AeroElectric-Archive.digest.vol-fa
November 27, 2005 - December 04, 2005
> running the battery ground right to the starter to bypass the high
> resistance steel frame tubes. The third option is to look for a starter
> with a lower current draw. I don=92t see that there=92s anything I can do
> about
> high frame resistance in the tubing.
>
>
> Questions:
>
>
> 9.2V at the battery while cranking seems low, indicating high internal
> resistance. I don=92t have another RG-35AXC battery for comparison. My
> battery is relatively new but has had a hard life of very hard starts and
> deep discharges. Any ideas or measurements on what the battery should be
> putting out?
>
>
> Does anybody have experience with a geared starter for big bore
> continentals
> such as the Sky-Tec C12ST3, which are claimed to have lower current draw
> and
> higher torque? The lighter weight would also help offset the weight gain
> from copper cable vs. the old aluminum conductor.
>
>
> Any ideas and demonstrated experience for dealing with high tubing-frame
> resistance? Short of trying multiple ground spots searching for the
> lowest
> resistance, I can=92t think of any other techniques to fix this especially
> in-situ.
>
>
>
________________________________________________________________________________
| From: | "Russell Williams" <rw_flyer(at)hotmail.com> |
| Subject: | Bellanca starter debugging |
Thanks David, good suggestions. My battery is a sealed Concorde recombinant
gas RG-35, so can't look for a bad cell as you suggest. Yes I do put it
onto a battery maintainer when left unflown for more than a week. The
voltage drop on the contactors in my system test out ok, but that's worth
looking at again to be sure.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of David
Lloyd
Subject: Re: AeroElectric-List: Bellanca starter debugging
WOW.... looks like you covered about everything.
I would have guessed bad terminals and, or bad starter contactor.
I have known several cases (Cessna) that had the same troubles with not
getting enough current into the starter for proper operation. Theirs turned
out to be the contactor, even though it "seemed" to test good. I would
certainly entertain the idea of swapping it out for a test. Maybe a hanger
buddy has a spare or will loan you his known good one just to try.
Another thought... how old is the battery and how is the charge maintained?
An apparently good battery, it powers most things on the buss, etc. ok,
could have a bad cell that will not keep pace with the other cells when
trying to produce and pass 300+ amps. If I recall, a well maintained
battery should hold about 10.5+ volts when under such a heavy current load
request. If the battery has a failing cell, then, it will not be able to
contribute to the working voltage.
One simple way to check this, remove all the battery caps, have a way to
look into all the cells, wear protective face gear and look at all the cells
while someone cranks on the engine for 15 secs. The bad cell will
bubble(gas) pretty vigorously. The remainder cells should be relatively
quiet.
If you have access to electric power, I suggest you install a small battery
"maintainer". I have used one for years. After I park the plane, I clip on
the maintainer ( I have a battery jumper port). On a 12 v system, the
little maintainer should bring the battery up to about 14.1 v and then,
shuts down the "charger" section and goes into a "float" mode and or pulse
mode of operation that holds that battery at about 13.1 to 13.3 volts. Both
settings are a bit critical. My last Gill 35, I used for 7 years via this
system. I finally installed a new battery and moved the Gill to a fueler
tank set-up. I was concerned about the Gill only in that I spend a lot of
time in the back country and did not want to face a possible non-start in
the bush just because I was a penny pincher.
David
----- Original Message -----
From: "Russell Williams" <rw_flyer(at)hotmail.com>
Subject: AeroElectric-List: Bellanca starter debugging
>
>
> I=92m working on debugging weak starting on my Bellanca 14-19-2
> Cruisemaster,
> and am looking for some input & validation of ideas. Here=92s the setup:
>
>
> Continental O-470 engine
>
> Lamar 12V permanent magnet starter =96 bench checked by the factory as ok.
>
> Concorde RG-35AXC battery =96 1 year old.
>
> Cables forward of the firewall that jump to the starter are 2 ga copper,
> about 1 foot in total length.
>
> The battery and master relay are located just forward of the horizontal
> stabilizer due to W&B. There is a 14=92 run of conductor to get from the
> master relay to the firewall.
>
>
> The starting behavior has been that when cold, I have to =93bump=94 the
> starter
> to get it to go over, usually it takes 3-5 tries before it will finally
> kick
> over and rotate freely. When warm, I=92m lucky to get it to turn over at
> all,
> usually I get =BD rotation before it hangs up. It is not slippage in the
> starter adapter, it is the starter motor. Fortunately my engine starts
> very
> easy once it is actually turned.
>
>
> Problem #1: The Bellanca designers were =93clever=94 and used a 3/8=94
> aluminum
> rod (covered in a vinyl sleeve for insulation) as the battery conductor up
> to the firewall. The ends of the rod were smashed flat and a hole drilled
> in them to make a terminal end. The firewall through-bolt was made of
> steel.
>
>
> Starting behavior has been progressively getting worse over the years, and
> a
> few weeks ago started to cook the rubber booties on the terminal ends of
> the
> battery conductor rod, with smell and a wisp of smoke in the cockpit.
> This
> prompted a replacement.
>
>
> Solution A: Rip and replace the aluminum rod with 0 ga aircraft wire.
> Replace the steel firewall through-bolt with a copper threaded-rod
> conductor
> and copper nuts. Cold starter turnover showed an improvement, but still
> not
> reliable full turnover rotation. Required 1 maybe 2 bumps to get full
> rotation (cold) going.
>
>
> Problem #2: The jumper from the starter relay to the starter was getting
> quite warm.
>
> Solution B: Replace this cable with 2 ga wire and new terminal ends. The
> jumper is no longer heating up, and is now measuring 0.06V drop while
> cranking.
>
>
> Problem #3: Measuring voltage drops on the system with the new cable,
> I=92m
> seeing 9.2V at the battery while cranking (13V static) and 7.5V at the
> starter. The positive side current path that I can measure with short
> voltmeter leads (battery to master relay, master relay, jumpers from
> firewall through bolt to starter relay, relay, starter relay to starter)
> were measuring under 0.2V cumulative drop, and I=92m estimating another
> 0.35V
> drop in the 14=92 cable based on a resistance calculation and estimated
> 250A
> starter current, for a total of ~0.55V drop.
>
>
> The remaining ~1.2V is in the ground return path. The engine to mount
> ground is good with negligible voltage drop, but the airframe is
> apparently
> high resistance and the airframe tubes (not the jumper cable) closest to
> the
> battery gnd connection point are warm to medium-hot. I have tried two
> different grounding points on the airframe, including jumpering the ground
> point about 6=92 forward on the airframe, and in all cases the behavior
> remains the same and the tubes are still getting hot.
>
>
> For diagnosis I=92ve temporarily jumpered the battery ground directly to
> the
> starter mounting stud on the engine with about 18=92 of 0 ga copper wire.
> The
> starter now reliably turns over when cold, and no wire or terminal heating
> is present. With the jumper in place I=92m getting 9.2V at the battery
> and
> about 8.5V at the starter while cranking. I=92m attributing the
> discrepancy
> in system voltage drop vs. the previous measurements and estimate as
> having
> over-estimated the current draw of the starter. Assuming about a 200A
> draw
> then the math works out given the known resistance of 0 ga wire.
>
>
> I see three solution options: first is the battery =96 low cranking
> voltage.
> Second is to put in a second copper wire for the ground side of the
> circuit,
> running the battery ground right to the starter to bypass the high
> resistance steel frame tubes. The third option is to look for a starter
> with a lower current draw. I don=92t see that there=92s anything I can do
> about
> high frame resistance in the tubing.
>
>
> Questions:
>
>
> 9.2V at the battery while cranking seems low, indicating high internal
> resistance. I don=92t have another RG-35AXC battery for comparison. My
> battery is relatively new but has had a hard life of very hard starts and
> deep discharges. Any ideas or measurements on what the battery should be
> putting out?
>
>
> Does anybody have experience with a geared starter for big bore
> continentals
> such as the Sky-Tec C12ST3, which are claimed to have lower current draw
> and
> higher torque? The lighter weight would also help offset the weight gain
> from copper cable vs. the old aluminum conductor.
>
>
> Any ideas and demonstrated experience for dealing with high tubing-frame
> resistance? Short of trying multiple ground spots searching for the
> lowest
> resistance, I can=92t think of any other techniques to fix this especially
> in-situ.
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Bellanca starter debugging |
>
>9.2V at the battery while cranking seems low, indicating high internal
>resistance. I don=92t have another RG-35AXC battery for comparison. My
>battery is relatively new but has had a hard life of very hard starts and
>deep discharges. Any ideas or measurements on what the battery should be
>putting out?
9v is not bad . . . if the starter is drawing 300+ amps.
Have you measured voltage AT the starter terminals too?
Have you measured total ground side drop? Quite often in
older airplanes, the ground side resistances can be as much
or more than the hot side resistances.
>Does anybody have experience with a geared starter for big bore continentals
>such as the Sky-Tec C12ST3, which are claimed to have lower current draw and
>higher torque? The lighter weight would also help offset the weight gain
>from copper cable vs. the old aluminum conductor.
Many peddlers toss out phrases like 'new and improved' and 'lower
current' and 'higher torque' without publishing the repeatable
experiment where brand A model X is compared under the same
conditions with brand C model Y. Lightplane Maintenance indicated
an interest in financing such a study about 10 years ago but never
heard from them again after the initial conversation. It would be
VERY interesting to do a single test-stand comparison for the
various modern products compared with the ol' Prestolite pigs.
The most consistent report I've heard from individuals who replaced
the Prestolite with ANY of the newer technologies is improved starting
performance because the engine turns over FASTER. Horsepower is
horsepower is HORSEPOWER. If brand X cranks faster than brand C
then it is either (1) more efficient, or (2) takes more electrical
power or (3) both. I can buy into the greater efficiency . . . to
a point. With higher gear ratios, the armature can run faster which
means higher counter EMF with fewer turns on the armature. Fewer
turns means lower I(squared)*R losses. Going from series field
(pure electrical loss, energy expended in field contributes nothing
to HP output) to permanent magnet is also an opportunity
to recoup electrical losses.
The astute buyer is justified in being skeptical of such claims.
The bottom line is, how does the new starter crank compared to
the old starter? All other things being equal (wiring drops,
battery impedance, contact and joint drops), if the new starter
does BETTER than the old starter, then who cares if it takes more
power or not? For example, if I could rewind the armature and
field of an old Prestolte and achieve a perceived improvement
in the ability to get the engine going, then there would probably
be market for that service.
To be sure, if such a mod requires MORE power, then battery service
life will suffer. Then again, if the owner operator adopted the
policy of a new el-cheeso battery every year, then perhaps the
performance of even the P-pig would be found acceptable.
Without good data, it's not very useful to compare the value
of one starter over another without first specifying design
goals for all components in the SYSTEM and accounting for all
the ways that variables interact. Short story is, don't get
sucked in by anybody's marketing hype. Your best source of
feedback is from users and even then, you should get the
largest sample possible.
>Any ideas and demonstrated experience for dealing with high tubing-frame
>resistance? Short of trying multiple ground spots searching for the lowest
>resistance, I can't think of any other techniques to fix this especially
>in-situ.
This is an old airplane. I presume that at some time in its
past, cranking performance was deemed adequate. If it's not
adequate now, then one and probably many things have changed.
Check the ground and hot-side drops independently of each
other and get back with us. Ground side drops in a biz-jet
with 700A starter draws is generally under 0.5 volts!
Bob . . .
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: No Solenoid Wiring Scheme (diagram for your comments) |
George et al ....
How about one manual contactor to supply the starter feed. Once the engine
is running turn off (open) the manual contactor. The hot side of the manual
contactor can feed a circuit to a small relay for the battery buss. Manual
contactors are available at the local farm store for under $10 and are both
simple and lighter than solenoid contactors. Of course they burn no juice
when closed. When opened there is no hot feed going to the starter. If the
manual contactor fails to make the circuit to feed the starter it doesn't
affect the rest of the aircraft electrical circuits. In my RV8A the manual
contactor would be accessible to be "hot wired", across the two contacts, to
start the engine.
How would such a circuit look, in comic book format, to include all the
diodes and the other protective devices this would require? What am I
missing with this proposal? It seems it would be safe when considering the
open circuit to the starter after engine start.
Jerry Grimmonpre'
RV8A
>
> It seemed over kill to have three solenoids under the cowl:
>
> FW Master: Has to be large to handle up to 300 amps flow thru to
> the starter
>
> FW Starter: Most modern aircraft starters (SkyTec) all have there
> own solenoid
>
> Starter: Has a big heavy duty solenoid already
>
> If you wire the battery to the starter direct you will by pass the
> firewall starter relay, which is not longer needed. Also since you
> no longer have to feed the starter current thru the master you can
> use a small relay to supply the "switch" master buss in the
> cockpit. The mess on the fire wall has always looked terrible and
> has many large connections. This alternate way will save almost
> 2 lbs and 1 amp of wasted current (12 watts) in wasted power to
> the master contactor. Picture below:
>
> http://img520.imageshack.us/img520/7674/norelays21re.jpg
>
>
> I think this will work with no loss in function or safety. I suppose
> you could argue that the starter engages and back-drives as a
> generator. What is the chance of that? Slim or nil. Well if it is a
> concern add the firewall starter relay back. I see no reason to
> have a big old firewall master relay.
>
> George
>
>
> ---------------------------------
>
>
>
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: Radio Panel Ground Buss |
Excellent idea Bob, would these come with appropriate fasteners for good
electrical contact ... ?
Jerry G
> I'm not ready to put them into the catalog yet. Which one
> are you interested in? Vertical . . .
>
> http://www.aeroelectric.com/Pictures/Grounding/AGB_V.jpg
>
> Right_Angle . . .
>
> http://www.aeroelectric.com/Pictures/Grounding/AVG_RA.jpg
>
>
> Bob . . .
________________________________________________________________________________
| Subject: | Re: Garmin 300xl/KI-202 |
I use the Kelly Airchart system. They list all the changes in the
system, and update it with every cycle. So it is easy to keep track of
local changes. If it is legal to do, it would be worth the price.
Jim
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Latching power relays? (Bob how about NO relays?) |
Match: #10 Message: #27374 Date: Nov 26, 2005 From:
"Robert L. Nuckolls, III" Subject: Re:
Latching power relays? (Bob how about NO relays?)
>The probability of having these design features becoming
>root cause or even exacerbation of an accident
>is very low compared to other reasons for bending
>airplanes and breaking people.
Good point, the thing I would consider is in an accident the
Starter wire grounds and causes a spark causing a gas fire.
However as you say this is unlikely and electrical spark. An
electrical spark could happen even with firewall starter/master
relays.
Fuel lines are on left, two short, strong, well protect fuel
lines; one goes from the carb to mech fuel pump and than
another to the gascolator. In the event of a forced landing
you would turn the fuel tanks off and electric pump off.
Consider routing the starter cable across the front of the
engine and on the right side away from the fuel lines.
Even if the starter cable grounded it would be fuse protected.
>The airplane I learned to fly in did not have a master
>contactor.
>Only a switch in the battery lead under the passenger side
>seat. Works good, lasts a long time. It didn't have starter
>contactor either. There was a really fat push-button under
>the pilot's seat. Also works good and lasts a long time.
Was that the Wright Flyer, JUST KIDDING. Yes I have seen
mechanical cables to throw mechanical switches or just running
big wires into the cockpit to big switches. It just shows that what
is old is new again and nothing new under the sun. Thanks for the
reply you make a good point. Also Eric points to:
http://www.flamingriver.com/index.cfm/page/ptype=results/Category_ID=133/home_id=76/mode=cat/cat133.htm
The BIG SWITCH could be firewall mounted with lever or cable
activation. The RED push switch could be used also if located
where you could kick it (with out doing it unintentionally).
Thanks Bob and Eric, interesting. I am going to run the cost,
weight reliability pro/con numbers and see if it makes sense.
Here is my latest way to wire the starter, main power distribution
and I added the ND alternator with internal regulation wiring.
http://img500.imageshack.us/img500/3753/norelaysalt23xi.jpg
HERE IS WITH A "FOOT" ACTIVATED CUTOUT SWITCH
http://img454.imageshack.us/img454/9797/norelaysalt2ks4rc.jpg
George
---------------------------------
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | No Solenoid Wiring Scheme / ND alternator wiring |
I made a few modifications and added the ND alternator wiring
to the NO (almost) solenoid wiring scheme. As Eric pointed out
race cars have emergency battery disconnects that could be
incorporated in the firewall. I feel with a large fuse on the
starter wire, careful routing and protection the risk of not
being able to disable the the big wire to the starter is a
small risk.
http://img500.imageshack.us/img500/3753/norelaysalt23xi.jpg
I show a battery disconnect in this one but not sure if this is
needed since you can cut most of the power from most of the
aircraft with one relay.
http://img454.imageshack.us/img454/9797/norelaysalt2ks4rc.jpg
Comments?
George
---------------------------------
________________________________________________________________________________
| From: | "Bill Schlatterer" <billschlatterer(at)sbcglobal.net> |
| Subject: | Con(fusing) fusible link questions? Z11 and Z13 |
Bob, I understand that we size the fuse to the wire but I am a little
confused about when and where one would use a fusible link. In the Z11
figure, you show the E-Bus Alt Feed with a 7a fuse off the main battery bus
using 16g wire through a 1-3 switch and 16g unprotected wire to the E-Bus.
Now, in Z13, you show the same thing with a fusible link between the E-bus
Alt Feed switch and E-Bus.
Questions:
In Z11, are we using the 7a fuse to protect the switch since 16g wire could
take a 12.5 amp fuse or is it size related to the design load on the E-bus?
In Z11, why aren't we protecting the wire after the switch since it is hot
when the master is on and it's a pretty long wire?
In Z13, why are we using a 20g fusible link (protects at 7 amps?) on the
wire after the E-Bus Alt Feed switch but not in the Z11 figure?
In the Z13 case, would it be acceptable to run the alt e-bus feed to a tab
on the e-bus with a 7a fuse instead of using a fusible link to the bus stud?
Assumes available tab positions.
I assume that the two 16g wires connecting the D25 Diode are not fused
because they are very short? Same for the always hot feed from the battery
to the Main Battery Buss?
Thanks Bill S
RV7a Ark Fuse/Panel
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Radio Panel Ground Buss |
>
>Excellent idea Bob, would these come with appropriate fasteners for good
>electrical contact ... ?
Not sure what your question is. This would be used as described
starting on page 18-11 of:
http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
There are no fasteners expected to participate in the electrical
circuit. In fact, on metal airplanes, the user will be instructed
to ISOLATE the ground bus mounting screws from the metallic structure.
On systems where the panel components are isolated from system
ground (most composites), the ground block is best mounted to one
of the radio trays.
High quality grounding takes place using one of the two
options described in Figure 18-17.
Bob . . .
________________________________________________________________________________
| Subject: | Re: No Solenoid Wiring Scheme / ND alternator wiring |
In a message dated 11/27/05 8:02:51 PM Eastern Standard Time,
gmcjetpilot(at)yahoo.com writes:
>
> http://img454.imageshack.us/img454/9797/norelaysalt2ks4rc.jpg
>
George,
May I suggest the addition of a 70 amp fuse (or size appropriate to Max
system load) at the foot switch to feed the firewall pass through and remove it
from the starter side of the ANL 350 amp fuse. Then if the starter / sol shorted
it would not take down the whole electrical system.
Ed. Sadler
________________________________________________________________________________
| From: | "Mark R. Supinski" <mark.supinski(at)gmail.com> |
| Subject: | Re: Alternator terminals |
Thanks for the input, Bob.
I note the comment: "If I were going to use this alternator in any
application..." Which gets my antenna wiggling.
General concerns about internally regulated alternators not withstanding,
would you not recommend this alternator for a Z-19 based system?
Regards,
Mark
On 11/24/05, Robert L. Nuckolls, III wrote:
>
> nuckollsr(at)cox.net>
>
>
> >
> >
> >Haven't gotten any feedback from anyone yet. More investigation on my
> part
> >has turned up some additional info -- here is an auto wiring diagram for
> the
> >alternator.
> >
> >http://www.rx7.org/jes/images/altsys91.jpg
> >
> >I presume the "B/W" lead corresponds to the "B" lead from the Z diagrams.
> >The remaining L and S remain confusing to me -- obviously I need to use
> one
> >of them (how to tell them apart on the connector is problem for the
> future.)
> >
> >Still looking for an insightful someone to stear me in the right
> >direction...
>
> Interesting diagram. If one blows it up enough, you can
> see a schematic of the voltage regulator! Aha! DATA!
>
> See:
>
>
> http://www.aeroelectric.com/Pictures/Alternators/IR_Alternator_Circa_1980.pdf
>
> for a redrawn schematic of what you posted above.
>
> Assuming the diagram matches the machine you have, one may deduce
> that this alternator's regulator is one of those "latch on"
> devices. A "tickler" current coming in through EITHER the IGN switch
> and series light bulb circuit "L" or through terminal "S" on my
> diagram will bring this alternator on line.
>
> This particular regulator is very simple . . . only 10 discrete
> components. Bill of materials in manufacturing volumes under
> $1.00. I visited the Wells Electronics plant in Fon du Lac, WI
> in 1988 and saw the same devices being manufactured on ceramic
> substrates by automated machines. The guy who gave me the grand
> tour said that his typical regulator had a manufacturing cost of
> under $1.50. The machine that assembled them built about 1200
> regulators per hour.
>
> However, if one studies the diagram, you'll see that power to
> run the regulator and energize the field comes off a separate trio
> of diodes (D7-D9) separate from the diodes that rectify b-lead
> output power (D1-D6). Once the alternator comes up, removing power
> from either the "L" or "S" leads will have no effect . . . the
> alternator will continue to provide output.
>
> If I were going to use this alternator in any application, I would
> attempt to identify the "S" lead with an ohmmeter. Depending on
> the instrument, a resistance measurement from each of the two
> terminals with respect to alternator case ground should produce
> some evidence of continuity. In the case of the "L" terminal,
> continuity will be indicated irrespective of the polarity of
> the meter leads. For the "S" terminal, the included diode (D11)
> will cause one of the ohmmeter connections to show infinite ohms.
>
> I'd run the "S" terminal to the alternator control switch
> KNOWING that until some other provisions are installed, the
> switch only controls ONSET of alternator operation and cannot
> turn it OFF later.
>
> This is a good example of the value of having internal schematics
> to any product. You need this kind of DATA to deduce things
> not revealed by a manufacturer's data sheets -AND/OR-
> to confirm that some supplier has adequately understood the
> finer points of some product he's trying to sell you.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator terminals |
>
>
>Thanks for the input, Bob.
>
>I note the comment: "If I were going to use this alternator in any
>application..." Which gets my antenna wiggling.
>
>General concerns about internally regulated alternators not withstanding,
>would you not recommend this alternator for a Z-19 based system?
I have no basis to recommend it or discourage it. By "any application" I
meant that if I needed to discover a way to make it work anywhere,
I'd proceed as follows . . .
Bob . . .
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: No Solenoid Wiring Scheme / ND alternator wiring |
Thanks Mr. Ed. Sadler:
Yes, sound obvious when you say it. That is a good idea and well worth consideration,
thanks.
This is what I was thinking. The chance of the starter cable shorting is slim
and.....
Not shown is a true HOT BAT buss that is battery direct, NOT thru the 350 amp
fuse (as you suggest). If the 350 amp fuse blew (ouch), an emergency feed thru
the hot battery buss and gets the power back, with a throw of the switch, like
what Bob shows with the avionics buss and a diode bridge. However thinking
about it why have an emergency feed if you are direct to the battery. Getting
rid of the relays has advantage obviously, it is no longer a possible failure
point. Why have an emergency feed, switch, wires, fuses and diode? I like the
emergency feed but wounder why it would be needed if wired as you suggest. Also
you may not need protection if the wire feeding the BAT BUS distribution (Fuse
block or CB bank) is short.
Great idea and well worth the effort and it only adds one large fuse/CB and
a few connections.
Thanks again great idea, it is a work in progress and your suggestion is just
what I needed. Regards George
From: Pebvjs(at)aol.com
Subject: Re: No Solenoid Wiring Scheme / ND alternator wiring
In a message dated 11/27/05 8:02:51 PM Eastern Standard Time,
gmcjetpilot(at)yahoo.com writes:
>
> http://img454.imageshack.us/img454/9797/norelaysalt2ks4rc.jpg
>
George,
May I suggest the addition of a 70 amp fuse (or size appropriate to Max
system load) at the foot switch to feed the firewall pass through and remove
it
from the starter side of the ANL 350 amp fuse. Then if the starter / sol
shorted
it would not take down the whole electrical system.
Ed. Sadler
---------------------------------
________________________________________________________________________________
| Subject: | Re: Garmin 300xl/KI-202 |
Hello
I have to thank you guys for this topic, as it directly pertains to me. I
have one of the refurbished Garmin 300XL's and have been thinking about the
indicator. Winter is coming and the garage/fusalage is looking a bit less
attractive, so thoughts turn to the panel. I had purchased a CD of install
information off ebay a while ago. Just looked through it and there is noting on
this
unit. Where do you obtain the install manual/information such as the pin outs
and CDI lists?
Jim
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: No Solenoid Wiring Scheme (diagram for your comments) |
Dan and Jerry:
Good points:
>From: "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com>
>Dan wrote: "It seems that during service, the starter lead is an issue - drop
a
wrench against it and ground and you probably fry something."
Good point I am a big believer in protecting every thing from inadvertent grounding.
I don't like seeing big connections and battery terminals exposed. With
the traditional relay many builders leave the studs wide open. I think this
issue can be resolved by protecting exposed connections. This is more an issue
during maintenance than in flight, but good point. As far as it taking the whole
system down, Looking at the ANL fuse it has a delay. You could use the faster
acting ANN fuse or reduce the amp rating for faster fusing. The standard SkyTec
is about 260-280 amps MAX peak. The wire wound starters are down around
200 amps. Any way you vote for the starter contactor added back. It sounds like
BIG -OLD master is something you might be willing to leave off?
Jerry: From: "Jerry Grimmonpre" <jerry(at)mc.net>
Jerry wrote:
"How about one manual contactor to supply the starter feed. Once the engine
is running turn off (open) the manual contactor. The hot side of the manual
contactor can feed a circuit to a small relay for the battery buss"
Actually based on Eric's suggestion I added an emergency shut off and posted
it. It is a manual switch which can cut off everything, like you are talking about.
The difference is it's only activated in an emergency. I can see your idea.
To start you engage the manual switch (assume fire wall mounted and push/pull
activated), start the engine and than turn off power to the starter, than
go fly. Interesting idea. I guess if I was going to worry about the #2 wire, I
would add the electric master back into the wiring.
For me personally I am not worried about the starter wire grounding. I think
the fuse will provide an acceptable level of safety. If I was not happy with
a fused HOT #2 starter wire.
These are all great ideas. The philosophy is for a lighter, simpler system that
maintains a high level of safety and function. The standard wiring scheme Bob's
shows in aero connection, using firewall master/starter contactors are very
good, reliable and safe. However the above idea should be as reliable or even
more reliable, while having a small weight, simplicity and efficiency advantage.
The cons are......
** I think the BIG or KEY HANG UPS I am hearing are two fold:**
Worry about an after crash fire started by sparks from the long starter wire.
Worry about an in-flight short of the #2 awg starter wire taking the system.
The first issue, my rationalization is the only part of the system to be HOT
in a crash (provided the pilot turned the master off) is the starter cable. So
if it shorts, the fuse blows in 0.10 seconds to 1 second. What will catch on
fire? Well fuel is the biggest worry to me. As long as you turned the fuel off
and aux pump the chance is small for the spark to catch anything on fire, as
long as the fuel tanks are not compromised. Fire is not a ZERO probability with
any plane or wiring. The solution is the emergency cut off Eric suggest. This
is like Jerry's suggestion, but Eric's suggestion is to have a cut off only
for emergencies. A firewall electric shut off may be better than a standard wiring
scheme from potential spark making.
Second: Will an in-flight partial or full short take the whole electrical system
down. Clearly it will be like starting the engine with the avionics on. The
voltage will draw down to X value (8 volts?) for a period of time until the
fuse blows. A dead short with a #2 will get your attention. My guess is it could
be like turning everything off for an instant. I guess the worst case is an
intermittent short, less than the rated fuse value, playing havoc with the radios.
Worse is if you have EFI or EI depended engine. That is why you would have
to secure and protect that big fat wire to assure that it can't happen (at
least 10 to the 99 power chance).
My thinking about "Electrics Light" has evolved. I think is makes sense and is
most suitable for day/night VFR, with engines not electric dependent. If you
are IFR with all electric flight instruments or have an electrical dependendant
engine, the greater electrical dependency calls for more "ISOLATION" and redundancy
clearly. However I think with careful routing and securing of the #2
awg starter cable (conduit) away from fuel (on a Lyc around front down the right
side), the risk is reduce, and post crash or in-flight failure risks are very
very unlikely. That is why we use the good wires, right.
Keep those comments coming. I am learning a lot. I see the trade offs more clearly.
It is also clear this is not a slam dunk either way.
Regards George
---------------------------------
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Garmin 300xl/KI-202 |
11/28/2005
Responding to Skip and Old Bob's inputs copied below:
Skip, Thanks for your question.
What if weather, clearance, aircraft malfunction, communication failure, or
whatever forces you away from your planned route and alternate in IMC
conditions. Do you personally want to be up there wishing you were down
here? Those of us who have been there and done that are not seeking a repeat
if it can be avoided.
I think the intent of the FAA is very clear -- current data base is required
for IFR operations -- and that an FAA ramp check inspector, an NTSB judge,
and a jury of your peers would agree with the FAA intent. I don't think that
anything that an amateur builder of an experimental aircraft wrote in his
aircraft's AFM or supplement would convince them otherwise.
Old Bob, Thanks for your always sagacious and well based input.
Did that 1997 Apollo GPS equipment Manual / Supplement provide suggested
wording that specifically permitted approval of IFR operations in IMC with
an outdated database? That would seem to be an operational issue and not a
hardware capability / functionality issue. Can you envision some GPS unit
manufacturer's company lawyer permitting that suggested wording today?
If wording of that nature is not in the GPS equipment manual how could it
get into the individual aircraft"s AFM or supplement?
In the AFM itself there are portions that are FAA approved and others that
are not. Could it also be that some parts of an AFM supplement related to
GPS use are not, in fact, FAA approved at some higher level but only
suggested? And those words are not FAA approved until the inspector
inspecting the individual installations says so? And the wording in the AIM
would be the controlling requirement? What installation inspector would
deliberately flout the wording in the AIM? I've never met an FAA employee
yet that was not concerned with packing paper around his ass that had
somebody else's approval.
With regard to checking to make sure that you have current data I once used
an out of date approach plate after assuring myself that the amdt number on
my plate was the same as the current plate. Turns out that communication
frequencies can be changed (and were on the plate that I was using) without
the amdt number on the plate changing. A bit embarrassing.
OC
Skip wrote:
<>
And Old Bob adds:
<| From: | Speedy11(at)aol.com |
| Subject: | Re: P-Mag Which Bus? |
In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
Interesting. I have dual Pmags, and neither one will self-power reliably
below
990 rpm.
Stormy,
So, if you lose electrical power except for battery, then you have to ensure
your RPM doesn't drop below 1000 when landing?
Stan Sutterfield
________________________________________________________________________________
| From: | "Mike" <mlas(at)cox.net> |
| Subject: | B&C Alternator field breaker tripping. |
Bob,
I have a question on trouble shooting an aircraft electric system, I'm
looking for the experienced answer based on symptoms. The airplane is a
9 year old Lancair 360 currently owned by the original builder. The
system is 12 volt with a B&C alternator and voltage regulator (working
on model numbers) on a Lycoming IO-360. The system has been working
perfectly until last spring, at which time the system would trip the
field breaker every now and then. The problem has been more pronounced
during periods of cooler weather (Phoenix Arizona). The owner has had
the alternator tested locally with no problems found. Most of the time
the system works as designed. My latest advice to the owner was to
check the engine, alternator, main bus, and voltage regulator grounds
first. Wondering what you think?
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: Re: AeroElectric-List: Alternator terminals
>
>
>Thanks for the input, Bob.
>
>I note the comment: "If I were going to use this alternator in any
>application..." Which gets my antenna wiggling.
>
>General concerns about internally regulated alternators not
withstanding,
>would you not recommend this alternator for a Z-19 based system?
I have no basis to recommend it or discourage it. By "any
application" I
meant that if I needed to discover a way to make it work anywhere,
I'd proceed as follows . . .
Bob . . .
--
11/24/2005
--
11/24/2005
________________________________________________________________________________
| From: | Earl_Schroeder <Earl_Schroeder(at)juno.com> |
| Subject: | Re: B&C Alternator field breaker tripping. |
Mike,
I'm not 'Bob' but I had a similar experience with my Lancair 235/320
when I had a 'large' alternator installed. [I have the B&C reg also].
When the gear pump kicked in [retracting the wheels] the field breaker
would always pop. For unrelated reasons, I switched to the smaller of
the two B&C alternators and the field breaker holds. I think the large
alternator could simply draw more than 5 amps when trying to keep up
with the gear pump demand. I think a larger field breaker is a likely
solution. I think the small Panasonic battery with limited 'immediate
need' capacity was also a factor. Choosing that particular battery
model was a mistake since corrected but done after switching to the
smaller alternator. Cooler weather probably just increases the current
required to the pump. Earl
Mike wrote:
> The system has been working
>perfectly until last spring, at which time the system would trip the
>field breaker every now and then. The problem has been more pronounced
>during periods of cooler weather (Phoenix Arizona).
>
>
>
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> Bus? |
| Subject: | Re: P-Mag minimum speed was P-Mag Which |
Bus?
At 09:30 AM 11/28/2005, you wrote:
>
>
>In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
>aeroelectric-list-digest(at)matronics.com writes:
>
>Interesting. I have dual Pmags, and neither one will self-power reliably
>below
>990 rpm.
>
>
>Stormy,
>So, if you lose electrical power except for battery, then you have to ensure
>your RPM doesn't drop below 1000 when landing?
>Stan Sutterfield
Stormy,
What is the spark plug gap on the plugs run by your P Mag? Magnetos use a
small gap (.018") to ensure that they will reliably fire the plugs during
slow speed (engine cranking) operation.
Charlie Kuss
________________________________________________________________________________
| From: | "Ralph Keeping" <Ralph_Keeping(at)cbc.ca> |
| Subject: | Re: RF Radiation |
Sorry if I missed it but what size capacitors would you use to filter
out the vhf band?
Ralph
>>> nuckollsr(at)cox.net 11/25/05 11:34 PM >>>
>
> Avionics-List message previously posted by: "Paul McAllister"
>
>
><having problems
>with RF getting into systems and causing problems.
>
>The first area is headsets, I couldn't get my Lightspeeds to work
properly.
>Lightspeed
>acknowledged that there can be problems and offered to modify the
battery
>box. That improved things, but from time to time I still have
problems.
>
>The next on the list is my Navaid. Despite following Navaids
suggestion of
>disabling
>the Navaid whenever the PTT is pressed I still have issues, if I
transmit
>for long enough it will still swing over to a 30 degree bank which is
a real
>pain if I am flying in IFR conditions.
>
>The latest trick is my intercom. Occasionally when I transmit I will
get a
>stuck
>mike. I called the manufacturer and managed to speak to the design
>engineer.
>He acknowledged that is there is enough RF present then this could
happen.
>The company are currently working with me to resolve the issue.
>
>So..... does anyone have any ideas. I have a GX60 as my nav / com and
the
>antenna
>(which is a Bob Archer) is buried in the tail. I have a single point
ground
>on the firewall.>>
Your ground system is probably not a participant in the problems
you're
experiencing. Given that you have so many different systems being
adversely
affected, it appears that your cockpit space may be subject to an
extra-
ordinarily high RF field.
First, I would make SURE that the radiation is coming from the
normally working antenna as-installed. Can you put a temporary
dummy load on the end of the coax before it goes into the vertical
fin? If the problems go away, then it's normally radiated energy
directly from the antenna. If the problem is still there, you have
a coax joint open at a shield somewhere. When the inside of an
airplane is this 'hot', it's a strong suggester of a compromised
feed line.
If the problems go away when the antenna is disconnected, try a
belly mounted antenna with ground plane. This could reduce energy
in the cockpit by 10db or more.
The alternatives are to modify your affected systems to include
the kind of filtering we generally design into vulnerable systems
as a matter of course. I spent 7 days in Little Rock adding
filters
to a 1960's product that couldn't stand the 50-100 v/m
interference
present in some current production airplanes. 16 little capacitors
were added to the backshell of the connector and potted. See:
http://www.aeroelectric.com/Pictures/Filters/filter_caps.jpg
http://www.aeroelectric.com/Pictures/Filters/potted_filter.jpg
This is a crummy way to run an airplane accessories business.
These SHOULD have been built into the device in the first place.
Your task is similar. Deduce which wires are vulnerable (you
need schematics of the accessories). Built test filters to
see what works. See:
http://www.aeroelectric.com/Pictures/Filters/breakout_filter_1.jpg
http://www.aeroelectric.com/Pictures/Filters/breakout_filter_2.jpg
These are filters required in the 2-30 MHz world. Since your
problem is VHF (118-135 MHz) you might get by with ferrite beads.
But even the ferrite bead doesn't work well if there is no
downstream,
shunt reactance (capacitor) to take advantage of the ferrite
bead's series inductance. Then figure out how to get the necessary
filtering either inside the victim accessory or right at the
connector outside the accessory.
In the OBAM aircraft world, you're ALLOWED to do anything you
need to to to fix a problem. In the certified world, getting
those caps installed was agonizingly difficult for non-technical
reasons. Your best first step is to see if a different antenna
style and
location will work. Then go after the filters . . .
Bob . . .
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
Charlie Kuss Bus? wrote:
>
>At 09:30 AM 11/28/2005, you wrote:
>
>
>>
>>
>>In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
>>aeroelectric-list-digest(at)matronics.com writes:
>>
>>Interesting. I have dual Pmags, and neither one will self-power reliably
>>below
>>990 rpm.
>>
>>
>>Stormy,
>>So, if you lose electrical power except for battery, then you have to ensure
>>your RPM doesn't drop below 1000 when landing?
>>Stan Sutterfield
>>
>>
>
>Stormy,
> What is the spark plug gap on the plugs run by your P Mag? Magnetos use a
>small gap (.018") to ensure that they will reliably fire the plugs during
>slow speed (engine cranking) operation.
>Charlie Kuss
>
Morning, Charlie...
Sounds like you're not that familiar with the P Mag. If I understand
your email right, you are asking if reducing the plug gap might produce
the same results as on a "normal" magneto.
The reason the P mag can't perform at low RPM applies ONLY if the
plane's power supply is gone for some reason.
It works normally if you still have a battery or alternator running. If
ALL power to it is gone, then it has it's own internal alternator, that
takes over...which doesn't put out enough power at low RPMs to work
well...just at higher engine speeds.
That is why they recommend one emag and one P mag. The emag will not
work at all if the plane's power is totally gone...with the p mag, you
have at least one mag still working even with power off, although you
have to maintain a higher RPM for it to work.
Which is a bit better than other electric ignition systems, they don't
work at all if the plane's power is gone.
Harley Dixon
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: RF Radiation |
>
>
>Sorry if I missed it but what size capacitors would you use to filter
>out the vhf band?
The test-filter I illustrated had L/C filters using
10 uHy/.01 uF sections with the inductor facing aircraft
wiring. These components were VERY effective at the 4.5
MHz antagonist of interest.
For VHF signals, I'd try devices about 1/10th that size.
0.5 to 1 uHy (or ferrite bead) and .001 uF monolythic
ceramic capacitors.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: B&C Alternator field breaker tripping. |
>
>
>Mike,
>I'm not 'Bob' but I had a similar experience with my Lancair 235/320
>when I had a 'large' alternator installed. [I have the B&C reg also].
>When the gear pump kicked in [retracting the wheels] the field breaker
>would always pop. For unrelated reasons, I switched to the smaller of
>the two B&C alternators and the field breaker holds. I think the large
>alternator could simply draw more than 5 amps when trying to keep up
>with the gear pump demand. I think a larger field breaker is a likely
>solution. I think the small Panasonic battery with limited 'immediate
>need' capacity was also a factor. Choosing that particular battery
>model was a mistake since corrected but done after switching to the
>smaller alternator. Cooler weather probably just increases the current
>required to the pump. Earl
What you were probably experiencing was a momentary overshoot
response that is produced by ALL alternators irrespective of
size. The magnitude and duration of the event is dependent on
MANY variables including alternator transfer function, regulator
transfer function, wiring arrangement, battery condition and
size/duration of the antagonist pulse (hydraulic pump motor).
A larger battery might have "fixed" the problem too.
It's likely that your system dynamics with the smaller alternator
were within the upper bounds for OV protection system sensitivity
to such transients. It's worth noting that this phenomenon is NOT
unique to the crowbar ov protection system. I used to work
similar problems during my earliest experiences with OV protection
relays.
A larger field breaker is NOT a solution. No alternator on the
market can draw more than 5A of field current. If your B&C
regulator fusses, it's system dynamics, not alternator field
loads.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: B&C Alternator field breaker tripping. |
>
>Bob,
>
>I have a question on trouble shooting an aircraft electric system, I'm
>looking for the experienced answer based on symptoms. The airplane is a
>9 year old Lancair 360 currently owned by the original builder. The
>system is 12 volt with a B&C alternator and voltage regulator (working
>on model numbers) on a Lycoming IO-360. The system has been working
>perfectly until last spring, at which time the system would trip the
>field breaker every now and then. The problem has been more pronounced
>during periods of cooler weather (Phoenix Arizona). The owner has had
>the alternator tested locally with no problems found. Most of the time
>the system works as designed. My latest advice to the owner was to
>check the engine, alternator, main bus, and voltage regulator grounds
>first. Wondering what you think?
See my post to another response to your question as well.
The B&C regulators were updated a few years ago to reduce
sensitivity to system dynamics and extraordinary noises on
the bus. Call B&C and see if they'll update your regulator.
If it's ten years old, it does not have these modifications.
If they can't do it for you, send it to me.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: P-Mag Which Bus? |
>
>
>In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
>aeroelectric-list-digest(at)matronics.com writes:
>
>Interesting. I have dual Pmags, and neither one will self-power reliably
>below
>990 rpm.
>
>
>Stormy,
>So, if you lose electrical power except for battery, then you have to ensure
>your RPM doesn't drop below 1000 when landing?
If you're running e-mags, they MUST be powered by the
ship's electrical system at all times. I recommend powering
from the always-hot, battery bus. IF you believe in assertive
preventative maintenance of the ship's battery, likelihood
of loss of ignition system power is exceedingly small (meaning
won't happen in this century).
If you run p-mags, there are dual sources of power for each
ignition system. Ship's battery -AND- a built in PM alternator
that supports the ignition system at all RPM's above some
published value. This means that dual p-mags enjoy the same
levels of redundancy as the certified Laser ignition system.
There's been some discussion recently about "reliability"
which correctly cites the case where installing two identical
systems offers TWICE the probability of failure for ignition
systems on board . . . of course, what we're REALLY interested
in is probability of losing too many essential components of
the ignition system(s) during any single flight (one tank
of gas).
Obviously, ADDing redundancy increases cost of ownership
and probability of increased maintenance activity. On the
other hand, having say FIVE independent ignition systems
offers no practical increase in flight safety and unnecessarily
burdens both the design and maintenance persons.
Dual e-mags offers the same or better suite of features
as ANY of the popular electronic ignition systems on the
market. Dual p-mags offers the same or better suit
of features as the certified LASAR system. There are
lots of folks flying with varied combinations of mags/
electronic+mags/all-electronic variants and each owner
operator is willing to expound at length on the rationale
for his/her decision.
Bottom line is that when I walk up to a certified rental,
concerns for reliability of that machine's ignition
systems is the furthest thing from my mind. Do what makes
sense to your pocketbook and space/weight budget for
your project. The debate on suitability of one configuration
over another will go on for decades, you need to finish
your airplane SOONER.
Bob . . .
________________________________________________________________________________
| Subject: | Re: B&C Alternator field breaker tripping. |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Mike -
He might also consider replacing the Circuit Breaker if the grounds check
out OK.
Per Z-14, we installed a fuseable link at the buss in the wire that goes
to the breaker. Those connections also may be corroded or a source of
trouble if installed.
Cheers,
John
Lancair ES - 95%/95%
> My latest advice to the owner was to
> check the engine, alternator, main bus, and voltage regulator grounds
> first. Wondering what you think?
> Mike Larkin
--
________________________________________________________________________________
| From: | sportav8r(at)aol.com |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
Gap is someting like .035 (I'm at work now and can't look it up) but should have
no bearing on plug firing, I think.
The rpm issue is only there if ship's battery bus falls below about 8 volts or
so (P-mags can be hand-propped with only a 9v transistor battery for excitation,
I'm told). I don't expect this to ever be an operational issue for me, even
on final approach.
-Stormy
-----Original Message-----
From: Charlie Kuss <chaztuna(at)adelphia.net>
Subject: Re: AeroElectric-List: Re: P-Mag minimum speed was P-Mag Which Bus?
Bus?
At 09:30 AM 11/28/2005, you wrote:
>
>
>In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
>aeroelectric-list-digest(at)matronics.com writes:
>
>Interesting. I have dual Pmags, and neither one will self-power reliably
>below
>990 rpm.
>
>
>Stormy,
>So, if you lose electrical power except for battery, then you have to ensure
>your RPM doesn't drop below 1000 when landing?
>Stan Sutterfield
Stormy,
What is the spark plug gap on the plugs run by your P Mag? Magnetos use a
small gap (.018") to ensure that they will reliably fire the plugs during
slow speed (engine cranking) operation.
Charlie Kuss
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | P-Mag minimum speed was P-Mag Which Bus? |
>That is why they recommend one emag and one P mag. The emag will not
>work at all if the plane's power is totally gone...with the p mag, you
>have at least one mag still working even with power off, although you
>have to maintain a higher RPM for it to work.
>
>Which is a bit better than other electric ignition systems, they don't
>work at all if the plane's power is gone.
. . . which is why we strive to craft failure tolerant systems
that NEVER leave you without power.
Bob . . .
________________________________________________________________________________
| From: | Joseph Larson <jpl(at)showpage.org> |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
Bob,
Does your response indicate caution towards P-mag? It seems like
this is a relatively inexpensive and (by all appearances) reliable
backup. It would seem like the fault tolerate systems you advocate
coupled with a Emag/Pmag combo achieves an optimal solution.
-Joe
On Nov 28, 2005, at 1:41 PM, Robert L. Nuckolls, III wrote:
>
>
>
>> That is why they recommend one emag and one P mag. The emag will not
>> work at all if the plane's power is totally gone...with the p mag,
>> you
>> have at least one mag still working even with power off, although you
>> have to maintain a higher RPM for it to work.
>>
>> Which is a bit better than other electric ignition systems, they
>> don't
>> work at all if the plane's power is gone.
>
> . . . which is why we strive to craft failure tolerant systems
> that NEVER leave you without power.
>
> Bob . . .
________________________________________________________________________________
| From: | "Malcolm Thomson" <mthomson(at)showmeproductions.com> |
| Subject: | Amplifier for Garmin 340... |
0.15 HTML_TEXT_AFTER_BODY BODY: HTML contains text after BODY close tag
I currently have a Chelton flight display wired to the Garmin 340 Audio
panel. I am using the "Alt Warn" un-muted input for the terrain and other
warnings output by the Chelton. Unfortunately, the Chelton's output volume
is set to max and there is no adjustment on the 340 and the audio level is
too low. So, does anyone have a small amplifier circuit that would boost
the output of the Chelton before it goes into the Garmin?
Thanks
--
________________________________________________________________________________
| Subject: | Re: Amplifier for Garmin 340... |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Hello Malcolm -
Looks like you are flying now?
Try this website. Someone on this list recommended it a month or so ago.
http://www.quasarelectronics.com/3087.htm
Cheers,
John
BODY: HTML contains text after BODY close tag, Malcolm Thomson
wrote:
>
>
> I currently have a Chelton flight display wired to the Garmin 340 Audio
> panel. I am using the "Alt Warn" un-muted input for the terrain and
> other
> warnings output by the Chelton. Unfortunately, the Chelton's output
> volume
> is set to max and there is no adjustment on the 340 and the audio level
> is
> too low. So, does anyone have a small amplifier circuit that would boost
> the output of the Chelton before it goes into the Garmin?
>
> Thanks
>
>
--
________________________________________________________________________________
| From: | "Ralph Keeping" <Ralph_Keeping(at)cbc.ca> |
| Subject: | Re: RF Radiation |
Perfect; thanks for the info. That's exactly what I have used but I was
never sure I was in the right range.
R
>>> nuckollsr(at)cox.net 11/28/05 1:04 PM >>>
>
>
>Sorry if I missed it but what size capacitors would you use to filter
>out the vhf band?
The test-filter I illustrated had L/C filters using
10 uHy/.01 uF sections with the inductor facing aircraft
wiring. These components were VERY effective at the 4.5
MHz antagonist of interest.
For VHF signals, I'd try devices about 1/10th that size.
0.5 to 1 uHy (or ferrite bead) and .001 uF monolythic
ceramic capacitors.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> Bus? |
| Subject: | Re: P-Mag minimum speed was P-Mag Which |
Bus?
>
>Bob,
>
>Does your response indicate caution towards P-mag? It seems like
>this is a relatively inexpensive and (by all appearances) reliable
>backup. It would seem like the fault tolerate systems you advocate
>coupled with a Emag/Pmag combo achieves an optimal solution.
Not at all. If I were building an airplane today, I'd probably
install the system depicted in Z13-8 which shows a pair of p-mags.
But if at purchase decision time I found that an 'extra' $400 would
get me some equally attractive electro-whizzy, I'd have no problem
dropping to a pair of e-mags. If my engine came with magnetos that
I could not sell for good value, I'd run one mag and one e-mag.
I'd wear out the first mag and then put the second mag back on.
After using up the second mag, I'd replace it with another e/p-mag.
Electronic ignition systems will not pay for themselves by fuel
savings for all but a very few individuals who spend hundreds of
hours per year in high-altitude cruise. For the rest of us, COST
OF PLUGS is the big motivator with improved cranking performance
running a distant second.
The EASY decision is to choose from the suite of electronic ignition
systems presently in production.
In terms of performance, there isn't a nickle's worth of difference
between
them. In terms of comparing SYSTEM reliability of what's currently flying
in the vast majority of the GA fleet, I perceive no great incentive
for either encouraging or discouraging any particular configuration
of ignition systems. Running at least one electronic ignition should
get you better cranking and the promise of fuel savings under the right
conditions. Beyond that, weight, volume and cost of ownership govern.
Here, the Mag-Air folks have it hands down.
Bob . . .
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)earthlink.net> |
| Subject: | Re: P-Mag Which Bus? |
>
> Interesting. I have dual Pmags, and neither one will
> self-power reliably below 990 rpm.
>
>
> Stormy,
> So, if you lose electrical power except for battery, then you
> have to ensure
> your RPM doesn't drop below 1000 when landing?
> Stan Sutterfield
If the ship's battery is still putting out something like 8 volts, the Emag
or Pmag will operate from ship's power. If the voltage drops below about 8
volts, the Emag drops off and the Pmag switches to its internally generated
power. Only then does one need to keep the rpm above about 1000, which is
not an issue at approach and landing speeds, at least with a C/S prop. I
can't speak for fixed pitch, as they will turn slower, I believe.
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| From: | Jeff Peterson <jeffreyb.peterson(at)gmail.com> |
| Subject: | lamina position lights |
I posted photos of some LED red and green wing tip position lights here:
http://w1.lancair.net/pix/Lamina-LED-Positon-Lights
The LED arrays are from Lamina Ceramics. These have a very wide
illumination pattern,
essentially Lambertian, and are so bright that without any lens they meet
FAA specs in the
forward direction. The FAA specs require much lower intensity off the
forward direction, so
these lights are way over spec for other azimuths.
I just used a series resistor to set the current. Keep it simple. One amp
for the green, two for the red.
Note that the standard Whelen bulb also uses 2 amps so these create no more
heat
than the bulbs. They make a LOT more red or green light, however.
I will attach the LEDs to the aluminum heat sinks I made with thermal heat
sink grease.
Also, you will see my strobes in the photos. These are public service units
I bought on E-bay.
I made a toroidal lens of D shape cross section to project more light into
the azimuthal plane.
The lens was made from 1/2 inch plexiglas rod. I heated it with a heat gun
and bent it into a curve.
I then cut the cylindrical inner surface on a milling machine with a fly
cutter.
These are for my LNC2 (360), but a similar design would work almost any
experimental.
Cheers.
--
Jeff Peterson
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)earthlink.net> |
| Subject: | P-Mag minimum speed was P-Mag Which Bus? |
SNIP
> Electronic ignition systems will not pay for themselves by fuel
> savings for all but a very few individuals who spend hundreds of
> hours per year in high-altitude cruise. For the rest of us, COST
> OF PLUGS is the big motivator with improved cranking performance
> running a distant second.
>
SNIP
> Bob . . .
Bob, quite a few RV's around MN have one or two EI's installed, and our
consensus is that they do indeed pay for themselves quite rapidly, even in
sport flying. Having an advanced, higher intensity spark allows one to run
leaner at low power settings (or, equivalently, at high altitude). When
flying side by side with similar engine and airframes, it is not unusual at
all to see the mag'd plane burning 8.5 to 9.0 gph, while the one running
next to it with EI only 7.0 to 7.5. The savings is typically about $4/hour
at $3/gallon. Obviously not all side by side comparisons will yield the
same result, but we do these comparisons regularly. Many RVer's run at MP's
of only 22 or 23 inHg, which also amplifies the differences. I cruise at
155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph. I
have FI also, but tests have shown that most of the gain is with the
ignition system. Non EI'd RV's typically are in the 9gph range for these
speeds (the -4's are slightly faster).
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| From: | "Dennis Johnson" <pinetownd(at)volcano.net> |
| Subject: | Do I Need an Ammeter? |
Greetings,
I'm building a Lancair Legacy composite airplane, installing a "glass cockpit."
I'm using the Z-13 "all electric airplane on a budget" wiring plan. I'll have
a voltmeter, but I'm not planning to install an ammeter. I wonder if that's
a mistake.
I'll have one battery, a main alternator, and an SD8 aux alternator. Both alternators
have overvoltage crowbar protection. The main bus has a low voltage warning
light. I'm not planning to install an ammeter for several reasons: additional
weight of a shunt, higher parts count, more money, and the temptation
to do troubleshooting in flight that is better done on the ground. No voltmeter
means I'll have to test my pitot heat by touching it during preflight, but
other than that, is an ammeter worth the additional complexity, cost, and weight
in my robust electrical system?
Thanks,
Dennis Johnson
Legacy #257: finishing the engine installation and getting ready to start wiring
________________________________________________________________________________
| From: | "Matt & Jo" <archermj(at)swbell.net> |
| Subject: | Questions on Z-20 and Z-16 |
Questions for Bob. I bought the AeroElectric Connection and have really
enjoyed it. What a great reference. I live here in Wichita also. I am the
guy that bought it at your home.
I am planning on using a Jabiru 3300 in a Zodiac with basic Night VFR.
Nothing Fancy. I am planning on using a Low voltage monitor and a crowbar.
I am considering both Z-16 and Z-20 as the basis for my system.
On Z-20 - Why is the starter contactor required if there is already a
starter solenoid on the starter?
Why isn't there a contactor on the battery circuit? Are these Contactors an
S701-1?
Is the OV Relay an S704-1? Why doesn't it have a Diode like on Z-16?
Odyssey batteries are described as dry batteries. Is this the same as an RC
battery?
I am also looking at Z-16 for the Jab 3300. If I were to incorporate the
Voltage regulator from Z-20 into Z-16 is there anything that I need to be
concerned about?
Thanks for the help
Cheers
Matt
www.zodiacxl.com
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> Bus? |
| Subject: | Re: P-Mag minimum speed was P-Mag Which |
Bus?
>-----Original Message-----
>From: Charlie Kuss <chaztuna(at)adelphia.net>
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: Re: P-Mag minimum speed was P-Mag Which Bus?
>
>
>Bus?
>
>At 09:30 AM 11/28/2005, you wrote:
> >
> >
> >In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
> >aeroelectric-list-digest(at)matronics.com writes:
> >
> >Interesting. I have dual Pmags, and neither one will self-power reliably
> >below
> >990 rpm.
> >
> >
> >Stormy,
> >So, if you lose electrical power except for battery, then you have
> to ensure
> >your RPM doesn't drop below 1000 when landing?
> >Stan Sutterfield
>
>Stormy,
> What is the spark plug gap on the plugs run by your P Mag? Magnetos use a
>small gap (.018") to ensure that they will reliably fire the plugs during
>slow speed (engine cranking) operation.
>Charlie Kuss
>
>
>Gap is someting like .035 (I'm at work now and can't look it up) but
>should have no bearing on plug firing, I think.
>
>The rpm issue is only there if ship's battery bus falls below about 8
>volts or so (P-mags can be hand-propped with only a 9v transistor battery
>for excitation, I'm told). I don't expect this to ever be an operational
>issue for me, even on final approach.
>
>-Stormy
Stormy,
The amount of power that the P-Mag must generate when it is in fail safe
mode is dependent on the gap of the spark plugs. The wider the gap, the
more power must be produced to fire the plugs. You can reduce the plug gap,
which will allow lower RPM operation in fail safe mode. The trade off is,
that you will lose some of the fuel economy that electronic ignition gives
you due to it's superior fuel/air combustion. All in all, it's probably
better to leave the plugs gapped to .035" and keep in mind that you must
keep the engine speed above 1000 rpm when in fail safe mode. As with
everything in life, there is no free lunch.
For myself, I'd rather be forced to keep the engine speed a bit above a
normal idle during emergency operations (fail safe) rather than give up the
fuel economy given by the larger spark plug gaps. It's simpy a matter of
knowing the limitations of your equipment.
Charlie
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> Bus? |
| Subject: | Re: P-Mag minimum speed was P-Mag Which |
Bus?
At 11:05 AM 11/28/2005, you wrote:
>
>
>Charlie Kuss Bus? wrote:
>
> Bus?
> >
> >At 09:30 AM 11/28/2005, you wrote:
> >
> >
> >>
> >>
> >>In a message dated 11/28/2005 2:58:49 A.M. Eastern Standard Time,
> >>aeroelectric-list-digest(at)matronics.com writes:
> >>
> >>Interesting. I have dual Pmags, and neither one will self-power reliably
> >>below
> >>990 rpm.
> >>
> >>
> >>Stormy,
> >>So, if you lose electrical power except for battery, then you have
> to ensure
> >>your RPM doesn't drop below 1000 when landing?
> >>Stan Sutterfield
> >>
> >>
> >
> >Stormy,
> > What is the spark plug gap on the plugs run by your P Mag? Magnetos use a
> >small gap (.018") to ensure that they will reliably fire the plugs during
> >slow speed (engine cranking) operation.
> >Charlie Kuss
> >
>Morning, Charlie...
>
>Sounds like you're not that familiar with the P Mag. If I understand
>your email right, you are asking if reducing the plug gap might produce
>the same results as on a "normal" magneto.
>
>The reason the P mag can't perform at low RPM applies ONLY if the
>plane's power supply is gone for some reason.
>
>It works normally if you still have a battery or alternator running. If
>ALL power to it is gone, then it has it's own internal alternator, that
>takes over...which doesn't put out enough power at low RPMs to work
>well...just at higher engine speeds.
>
>That is why they recommend one emag and one P mag. The emag will not
>work at all if the plane's power is totally gone...with the p mag, you
>have at least one mag still working even with power off, although you
>have to maintain a higher RPM for it to work.
>
>Which is a bit better than other electric ignition systems, they don't
>work at all if the plane's power is gone.
>
>Harley Dixon
Harley,
I grasp the operation of the P-Mag. Bendix and Slick magnetos work the
same way. All generators, alternators and magnetos are speed dependent.
They can't produce a useful amount of current if the speed is to low.
However, the amount of spark needed to be produced by a magneto or P-Mag
(when in self generating mode) are both affected by the gap of the spark
plugs. Changing the spark plug gap WILL affect the minimum operating speed
of the P-Mags in fail safe mode. (without ships power)
The P-Mags will be reliable in fail safe mode, so long as the pilot
understands what the minimum RPM that they require to function is.
Charlie
________________________________________________________________________________
| From: | "Richard Sipp" <rsipp(at)earthlink.net> |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
----- Original Message -----
From: "Alex Peterson" <alexpeterson(at)earthlink.net>
Subject: RE: AeroElectric-List: P-Mag minimum speed was P-Mag Which Bus?
>
>
>
> SNIP
>> Electronic ignition systems will not pay for themselves by fuel
>> savings for all but a very few individuals who spend hundreds of
>> hours per year in high-altitude cruise. For the rest of us, COST
>> OF PLUGS is the big motivator with improved cranking performance
>> running a distant second.
>>
> SNIP
>> Bob . . .
>
>
> Bob, quite a few RV's around MN have one or two EI's installed, and our
> consensus is that they do indeed pay for themselves quite rapidly, even in
> sport flying. Having an advanced, higher intensity spark allows one to
> run
> leaner at low power settings (or, equivalently, at high altitude). When
> flying side by side with similar engine and airframes, it is not unusual
> at
> all to see the mag'd plane burning 8.5 to 9.0 gph, while the one running
> next to it with EI only 7.0 to 7.5. The savings is typically about
> $4/hour
> at $3/gallon. Obviously not all side by side comparisons will yield the
> same result, but we do these comparisons regularly. Many RVer's run at
> MP's
> of only 22 or 23 inHg, which also amplifies the differences. I cruise at
> 155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph. I
> have FI also, but tests have shown that most of the gain is with the
> ignition system. Non EI'd RV's typically are in the 9gph range for these
> speeds (the -4's are slightly faster).
>
> Alex Peterson
> RV6-A N66AP 694 hours
> Maple Grove, MN
>
>Bob:
I'll second Alex's data. My 4 has 9.0 to 1 compression/carb/CS prop and my
cruise fuel numbers are slightly better than Alex reports at 6.8 to 7.2 GPH
at cruise above 7000. Flying in large formations of RVs I always buy less
fuel than the others (granted several of them are heavier bigger models). I
maintain the groups speed usually about 150-160 KTAS at approx 2250 RPM and
23-24 inches MP.
Another important factor to me is the engine's smoothness, and reliable
starting.
Best regards
Dick Sipp
________________________________________________________________________________
| From: | "Richard Sipp" <rsipp(at)earthlink.net> |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
Harley,
Small point here, the Unison Lasar system also runs fine with total failure
of ship's power. The electrically controlled mag timing reverts to the
standard manufacturer's mag setting in the event of controller failure for
any reason.
Dick Sipp
>
> Which is a bit better than other electric ignition systems, they don't
> work at all if the plane's power is gone.
>
> Harley Dixon
________________________________________________________________________________
| From: | "Stein Bruch" <stein(at)steinair.com> |
| Subject: | Do I Need an Ammeter? |
Couple things....
Most "glass" (assuming you're including an engine monitor) systems include
both volts and amps, so your question may be a moot point.
2nd, a simple hall effect current sensor adds maybe 1/2 to 1 ounce and a
wire to the plane...not overly complex or heavy, so I wouldn't worry about
it.
Plan on both Volts/Amps and then you needn't worry!
Just my 2 cents as usual.
Cheers,
Stein.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Dennis
Johnson
Subject: AeroElectric-List: Do I Need an Ammeter?
Greetings,
I'm building a Lancair Legacy composite airplane, installing a "glass
cockpit." I'm using the Z-13 "all electric airplane on a budget" wiring
plan. I'll have a voltmeter, but I'm not planning to install an ammeter. I
wonder if that's a mistake.
I'll have one battery, a main alternator, and an SD8 aux alternator. Both
alternators have overvoltage crowbar protection. The main bus has a low
voltage warning light. I'm not planning to install an ammeter for several
reasons: additional weight of a shunt, higher parts count, more money, and
the temptation to do troubleshooting in flight that is better done on the
ground. No voltmeter means I'll have to test my pitot heat by touching it
during preflight, but other than that, is an ammeter worth the additional
complexity, cost, and weight in my robust electrical system?
Thanks,
Dennis Johnson
Legacy #257: finishing the engine installation and getting ready to start
wiring
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | RE: electronics vs. mags metrics |
>
>
>
>SNIP
> > Electronic ignition systems will not pay for themselves by fuel
> > savings for all but a very few individuals who spend hundreds of
> > hours per year in high-altitude cruise. For the rest of us, COST
> > OF PLUGS is the big motivator with improved cranking performance
> > running a distant second.
> >
>SNIP
> > Bob . . .
>
>
>Bob, quite a few RV's around MN have one or two EI's installed, and our
>consensus is that they do indeed pay for themselves quite rapidly, even in
>sport flying. Having an advanced, higher intensity spark allows one to run
>leaner at low power settings (or, equivalently, at high altitude). When
>flying side by side with similar engine and airframes, it is not unusual at
>all to see the mag'd plane burning 8.5 to 9.0 gph, while the one running
>next to it with EI only 7.0 to 7.5. The savings is typically about $4/hour
>at $3/gallon. Obviously not all side by side comparisons will yield the
>same result, but we do these comparisons regularly. Many RVer's run at MP's
>of only 22 or 23 inHg, which also amplifies the differences. I cruise at
>155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph. I
>have FI also, but tests have shown that most of the gain is with the
>ignition system. Non EI'd RV's typically are in the 9gph range for these
>speeds (the -4's are slightly faster).
The only DATA I've been working with came from an engine
guru at GM who was building a Longez and got permission to
run his O-235 in a test cell at GM. He installed one of
Lightspeed's ignition systems for comparison with mags and
he also did a lot of work comparing various carburetors.
This work was done about 15 years ago and he reported 5-7%
savings in fuel for the same horsepower output at altitude.
He reported no significant advantages at low altitudes
since the spark advance was minimal at high manifold
pressures and the increased spark energy didn't produce
measurable improvements over fresh plugs on a mag.
I've lost track of him. I'd really like to know if and
how any further tests turned out. Obviously, if one can achieve
practical operation of an engine with a savings of 1.5 gallons
out of 9, then my assertions based on earlier data are
wrong. It would be really cool if a group of you could
record some results for a controlled experiment and
publish your findings. I'd be pleased to post it on
aeroelectric.com.
Mr. Braly, are you listening in? Do you have any metrics
on the mags vs. electronics in a controlled experiment.
Hmmmm . . . wonder if the CAFE folks have studied this.
They're the most likely to have instrumented systems in
ways that could provide data. I'll poke around on their
website . . .
Bob . . .
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Just a reminder-- Google "Ipod altitude".
The Ipod uses a little teeny hard-drive that depends on a cushion of air to ride
above the disk. At altitudes above 10,000 feet the head and disk...well you
get the idea.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Hey, it ain'tt rocket surgery!"
--anonymous
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)earthlink.net> |
| Subject: | RE: electronics vs. mags metrics |
> It would be really cool if a group of you could
> record some results for a controlled experiment and
> publish your findings. I'd be pleased to post it on
> aeroelectric.com.
>
Bob, I have done some very basic work posted here:
http://www.home.earthlink.net/~alexpeterson/fuelflow.htm
I really need to update it, as it is somewhat understating the benefit of
EI, partly because I ignored the fact that the engine ran rough with the
magnetos whenever lean of peak, while the engine runs smooth down to
significant power loss on the lean side with the EI on. So, for the roughly
.5gph savings that the above site presents, one would have to run the mag'd
engine right at peak egt to be at that savings. In an RV, this will run the
engine in my plane at cht's of around 400 in the summer, someplace I don't
want to regularly run. I now have better egt and cht instrumentation than I
did when that data was collected, so I need to repeat the tests. However,
this time I will run the data further to the rich side of things.
All that being said, in the real world when a gaggle of us is flying
somewhere side by side, the typical difference is around 1.0 to 1.5 gph.
This is well established. However, the question might be whether or not the
higher burn rates are the result of incorrect mixture management.
The best articles that I know of about engine management are by John Deakin,
and can be found by digging through Avweb.com. They focus on FI engines,
but are of value to carb'd engines as well.
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| Subject: | P-Mag minimum speed was P-Mag Which Bus? |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Alex,
Re you comparing the same mixture regime for both the mag and EI
equipped airplane?
I.e, if the Mag airplanes are running rich of peak (ROP) and the EI's
are running lean of Peak (LOP) then that would explain the substantial
difference.
Now if you are saying having a mag makes it hard to run LOP then that
would justify your position but the gains you talk of seem "impressive"
if it is purely due to the ignition system.
Can you shed more light here?
Thanks
Frank
Rv7a Emag/Pmag, working on cowl.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Alex
Peterson
Subject: RE: AeroElectric-List: P-Mag minimum speed was P-Mag Which Bus?
-->
SNIP
> Electronic ignition systems will not pay for themselves by fuel
> savings for all but a very few individuals who spend hundreds of
> hours per year in high-altitude cruise. For the rest of us, COST
> OF PLUGS is the big motivator with improved cranking performance
> running a distant second.
>
SNIP
> Bob . . .
Bob, quite a few RV's around MN have one or two EI's installed, and our
consensus is that they do indeed pay for themselves quite rapidly, even
in sport flying. Having an advanced, higher intensity spark allows one
to run leaner at low power settings (or, equivalently, at high
altitude). When flying side by side with similar engine and airframes,
it is not unusual at all to see the mag'd plane burning 8.5 to 9.0 gph,
while the one running next to it with EI only 7.0 to 7.5. The savings
is typically about $4/hour at $3/gallon. Obviously not all side by side
comparisons will yield the same result, but we do these comparisons
regularly. Many RVer's run at MP's of only 22 or 23 inHg, which also
amplifies the differences. I cruise at
155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph.
I have FI also, but tests have shown that most of the gain is with the
ignition system. Non EI'd RV's typically are in the 9gph range for
these speeds (the -4's are slightly faster).
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| From: | John Huft <aflyer(at)lazy8.net> |
| Subject: | Re: RE: electronics vs. mags metrics |
version=3.0.3
Go to
http://www.cafefoundation.org/research.htm
and look at Ignition Dynamics I, II, and III
John
Robert L. Nuckolls, III wrote:
>
>
>
>>
>>
>>
>>SNIP
>>
>>> Electronic ignition systems will not pay for themselves by fuel
>>> savings for all but a very few individuals who spend hundreds of
>>> hours per year in high-altitude cruise. For the rest of us, COST
>>> OF PLUGS is the big motivator with improved cranking performance
>>> running a distant second.
>>>
>>
>>SNIP
>>
>>> Bob . . .
>>
>>
>>Bob, quite a few RV's around MN have one or two EI's installed, and our
>>consensus is that they do indeed pay for themselves quite rapidly, even in
>>sport flying. Having an advanced, higher intensity spark allows one to run
>>leaner at low power settings (or, equivalently, at high altitude). When
>>flying side by side with similar engine and airframes, it is not unusual at
>>all to see the mag'd plane burning 8.5 to 9.0 gph, while the one running
>>next to it with EI only 7.0 to 7.5. The savings is typically about $4/hour
>>at $3/gallon. Obviously not all side by side comparisons will yield the
>>same result, but we do these comparisons regularly. Many RVer's run at MP's
>>of only 22 or 23 inHg, which also amplifies the differences. I cruise at
>>155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph. I
>>have FI also, but tests have shown that most of the gain is with the
>>ignition system. Non EI'd RV's typically are in the 9gph range for these
>>speeds (the -4's are slightly faster).
>
>
> The only DATA I've been working with came from an engine
> guru at GM who was building a Longez and got permission to
> run his O-235 in a test cell at GM. He installed one of
> Lightspeed's ignition systems for comparison with mags and
> he also did a lot of work comparing various carburetors.
>
> This work was done about 15 years ago and he reported 5-7%
> savings in fuel for the same horsepower output at altitude.
> He reported no significant advantages at low altitudes
> since the spark advance was minimal at high manifold
> pressures and the increased spark energy didn't produce
> measurable improvements over fresh plugs on a mag.
>
> I've lost track of him. I'd really like to know if and
> how any further tests turned out. Obviously, if one can achieve
> practical operation of an engine with a savings of 1.5 gallons
> out of 9, then my assertions based on earlier data are
> wrong. It would be really cool if a group of you could
> record some results for a controlled experiment and
> publish your findings. I'd be pleased to post it on
> aeroelectric.com.
>
> Mr. Braly, are you listening in? Do you have any metrics
> on the mags vs. electronics in a controlled experiment.
> Hmmmm . . . wonder if the CAFE folks have studied this.
> They're the most likely to have instrumented systems in
> ways that could provide data. I'll poke around on their
> website . . .
>
> Bob . . .
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Mark R. Supinski" <mark.supinski(at)gmail.com> |
Note that this is correct, but only applies to hard-disk based IPods
(classic, photo, video). The solid-state IPods are of course not affected
by altitude (Mini, Nano, Shuffle).
Mark Supinski
On 11/29/05, Eric M. Jones wrote:
>
> emjones(at)charter.net>
>
> Just a reminder-- Google "Ipod altitude".
>
> The Ipod uses a little teeny hard-drive that depends on a cushion of air
> to ride above the disk. At altitudes above 10,000 feet the head and
> disk...well you get the idea.
>
> Regards,
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> (508) 764-2072
>
> "Hey, it ain'tt rocket surgery!"
> --anonymous
>
>
________________________________________________________________________________
| From: | "Wayne Sweet" <w_sweet(at)comcast.net> |
| Subject: | Re: P-Mag minimum speed was P-Mag Which Bus? |
To compare side-by-side fuel burns, mixture settings would have to be
identical. For example, the ideal comparison would be to run two planes, one
with non-EI and the other with dual or single EI AND BOTH having
multi-cylinder EGT/CHT instrumentation. Then both planes are set at
identical ROP or if both have GAMI's, LOP settings. Both would of course
have to be FI, since carburetor engines are extremely difficult to run LOP.
Then if one sees better mileage on the EI plane (this is instantly
observable since JPI and other multicyclinder instrumentation has a mileage
readout), and this experiment is repeatable (VERY IMPORTANT) in other like
planes, it will be much more conclusive.
Just my $0.02.
Wayne
----- Original Message -----
From: "Richard Sipp" <rsipp(at)earthlink.net>
Subject: Re: AeroElectric-List: P-Mag minimum speed was P-Mag Which Bus?
>
>
>
> ----- Original Message -----
> From: "Alex Peterson" <alexpeterson(at)earthlink.net>
> To:
> Subject: RE: AeroElectric-List: P-Mag minimum speed was P-Mag Which Bus?
>
>
>>
>>
>>
>> SNIP
>>> Electronic ignition systems will not pay for themselves by fuel
>>> savings for all but a very few individuals who spend hundreds of
>>> hours per year in high-altitude cruise. For the rest of us, COST
>>> OF PLUGS is the big motivator with improved cranking performance
>>> running a distant second.
>>>
>> SNIP
>>> Bob . . .
>>
>>
>> Bob, quite a few RV's around MN have one or two EI's installed, and our
>> consensus is that they do indeed pay for themselves quite rapidly, even
>> in
>> sport flying. Having an advanced, higher intensity spark allows one to
>> run
>> leaner at low power settings (or, equivalently, at high altitude). When
>> flying side by side with similar engine and airframes, it is not unusual
>> at
>> all to see the mag'd plane burning 8.5 to 9.0 gph, while the one running
>> next to it with EI only 7.0 to 7.5. The savings is typically about
>> $4/hour
>> at $3/gallon. Obviously not all side by side comparisons will yield the
>> same result, but we do these comparisons regularly. Many RVer's run at
>> MP's
>> of only 22 or 23 inHg, which also amplifies the differences. I cruise at
>> 155 to 165 ktas between 4 and 10k feet, burning around 7.1 to 7.4 gph. I
>> have FI also, but tests have shown that most of the gain is with the
>> ignition system. Non EI'd RV's typically are in the 9gph range for these
>> speeds (the -4's are slightly faster).
>>
>> Alex Peterson
>> RV6-A N66AP 694 hours
>> Maple Grove, MN
>>
>>Bob:
>
> I'll second Alex's data. My 4 has 9.0 to 1 compression/carb/CS prop and
> my
> cruise fuel numbers are slightly better than Alex reports at 6.8 to 7.2
> GPH
> at cruise above 7000. Flying in large formations of RVs I always buy less
> fuel than the others (granted several of them are heavier bigger models).
> I
> maintain the groups speed usually about 150-160 KTAS at approx 2250 RPM
> and
> 23-24 inches MP.
>
> Another important factor to me is the engine's smoothness, and reliable
> starting.
>
> Best regards
>
> Dick Sipp
>
>
>
________________________________________________________________________________
| From: | "Alan K. Adamson" <aadamson(at)highrf.com> |
One note, this is only true of the original 10, 15, 20, 30, 40, and 60G
Ipods and derivatives. The Nano, the Mini, the Shuffle, etc all use solid
state memory and shouldn't have this problem.
Alan
----- Original Message -----
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: AeroElectric-List: IPod Grinch
>
>
> Just a reminder-- Google "Ipod altitude".
>
> The Ipod uses a little teeny hard-drive that depends on a cushion of air
> to ride above the disk. At altitudes above 10,000 feet the head and
> disk...well you get the idea.
>
> Regards,
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> (508) 764-2072
>
> "Hey, it ain'tt rocket surgery!"
> --anonymous
>
>
>
________________________________________________________________________________
| From: | William Morgan <wmorgan31(at)netzero.net> |
| Subject: | RE: Bellanca starter debugging - Hot frame tubes |
Hello Russell,
I saw this same problem once on a motorcycle (Hot frame tube at
ground point, hard starting).
It turned out to be SEVERE internal corrosion of the frame tubes
discovered when the frame tube failed. The frame broke at the hot
spot and examination showed almost no metal and mostly all rust. It
turned out that the entire frame was rusting.
Scott
--
________________________________________________________________________________
| From: | "Lloyd, Daniel R." <LloydDR(at)wernerco.com> |
But they have a version that is 512 or 1 gb, that is solid state memory,
plugs into the USB post and is about the size of a pack of gum.
Sounds great and uses very little power and can hold 120 songs, and 240
for the larger one
Dan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Eric
M. Jones
Subject: AeroElectric-List: IPod Grinch
Just a reminder-- Google "Ipod altitude".
The Ipod uses a little teeny hard-drive that depends on a cushion of air
to ride above the disk. At altitudes above 10,000 feet the head and
disk...well you get the idea.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Hey, it ain'tt rocket surgery!"
--anonymous
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Mag Which Bus? |
Yup. We all understand and agree.
For Stormy, the question again is, "On battery power only, you must keep your
RPM above 1000 for landing or the engine is dead?" 990 RPM sounds low to me.
I'd ask the manufacturer about it.
Stan Sutterfield
In a message dated 11/29/05 2:58:21 AM Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
>Interesting. I have dual Pmags, and neither one will self-power reliably
>below
>990 rpm.
>
>
>Stormy,
>So, if you lose electrical power except for battery, then you have to ensure
>your RPM doesn't drop below 1000 when landing?
If you're running e-mags, they MUST be powered by the
ship's electrical system at all times. I recommend powering
from the always-hot, battery bus. IF you believe in assertive
preventative maintenance of the ship's battery, likelihood
of loss of ignition system power is exceedingly small (meaning
won't happen in this century).
If you run p-mags, there are dual sources of power for each
ignition system. Ship's battery -AND- a built in PM alternator
that supports the ignition system at all RPM's above some
published value. This means that dual p-mags enjoy the same
levels of redundancy as the certified Laser ignition system.
There's been some discussion recently about "reliability"
which correctly cites the case where installing two identical
systems offers TWICE the probability of failure for ignition
systems on board . . . of course, what we're REALLY interested
in is probability of losing too many essential components of
the ignition system(s) during any single flight (one tank
of gas).
Obviously, ADDing redundancy increases cost of ownership
and probability of increased maintenance activity. On the
other hand, having say FIVE independent ignition systems
offers no practical increase in flight safety and unnecessarily
burdens both the design and maintenance persons.
Dual e-mags offers the same or better suite of features
as ANY of the popular electronic ignition systems on the
market. Dual p-mags offers the same or better suit
of features as the certified LASAR system. There are
lots of folks flying with varied combinations of mags/
electronic+mags/all-electronic variants and each owner
operator is willing to expound at length on the rationale
for his/her decision.
Bottom line is that when I walk up to a certified rental,
concerns for reliability of that machine's ignition
systems is the furthest thing from my mind. Do what makes
sense to your pocketbook and space/weight budget for
your project. The debate on suitability of one configuration
over another will go on for decades, you need to finish
your airplane SOONER.
Bob . . .
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)earthlink.net> |
| Subject: | P-Mag minimum speed was P-Mag Which Bus? |
> -->
>
> To compare side-by-side fuel burns, mixture settings would
> have to be identical. For example, the ideal comparison would
> be to run two planes, one with non-EI and the other with dual
> or single EI AND BOTH having multi-cylinder EGT/CHT
> instrumentation. Then both planes are set at identical ROP or
> if both have GAMI's, LOP settings. Both would of course have
> to be FI, since carburetor engines are extremely difficult to run LOP.
> Then if one sees better mileage on the EI plane (this is
> instantly observable since JPI and other multicyclinder
> instrumentation has a mileage readout), and this experiment
> is repeatable (VERY IMPORTANT) in other like planes, it will
> be much more conclusive.
> Just my $0.02.
> Wayne
With the same airspeed, my airplane will burn .5 gph less than my same plane
with the EI (Lasar) turned off. (A Lasar equipped plane is the only one
which can run conventional mags and EI in the same flight.) So, if you
could run your particular mag'd engine at 50F lean of peak, the savings
going to EI would only be about .5gph. But, there is more to it as I've
already explained.
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| From: | sportav8r(at)aol.com |
| Subject: | Re: Mag Which Bus? |
This would seem to be the case for me- if both P mags were to be taken off the
ship's battery bus, or said bus were to drop below about 8 volts or so, then the
engine must me kept turning above 990 rpm to avoid complete loss of spark.
In practice, this rpm is very easy to maintain in landing regime, so it's more
something to know about than to worry about.
I'm not sure if both mags have the same dropout rpm, because my GRT EIS rpm indication
goes nuts (double) when I switch the P-mag which is sending the tach signal
off of bus power. No such effect when I switch the other P-mag to internal
power, however. Mysterious. I'll try to post an update on the particulars.
Every P-mag operator should determine this critical self-powering rpm limit
for themselves.
-Stormy
-----Original Message-----
From: Speedy11(at)aol.com
Subject: AeroElectric-List: Re: Mag Which Bus?
Yup. We all understand and agree.
For Stormy, the question again is, "On battery power only, you must keep your
RPM above 1000 for landing or the engine is dead?" 990 RPM sounds low to me.
I'd ask the manufacturer about it.
Stan Sutterfield
In a message dated 11/29/05 2:58:21 AM Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
>Interesting. I have dual Pmags, and neither one will self-power reliably
>below
>990 rpm.
>
>
>Stormy,
>So, if you lose electrical power except for battery, then you have to ensure
>your RPM doesn't drop below 1000 when landing?
If you're running e-mags, they MUST be powered by the
ship's electrical system at all times. I recommend powering
from the always-hot, battery bus. IF you believe in assertive
preventative maintenance of the ship's battery, likelihood
of loss of ignition system power is exceedingly small (meaning
won't happen in this century).
If you run p-mags, there are dual sources of power for each
ignition system. Ship's battery -AND- a built in PM alternator
that supports the ignition system at all RPM's above some
published value. This means that dual p-mags enjoy the same
levels of redundancy as the certified Laser ignition system.
There's been some discussion recently about "reliability"
which correctly cites the case where installing two identical
systems offers TWICE the probability of failure for ignition
systems on board . . . of course, what we're REALLY interested
in is probability of losing too many essential components of
the ignition system(s) during any single flight (one tank
of gas).
Obviously, ADDing redundancy increases cost of ownership
and probability of increased maintenance activity. On the
other hand, having say FIVE independent ignition systems
offers no practical increase in flight safety and unnecessarily
burdens both the design and maintenance persons.
Dual e-mags offers the same or better suite of features
as ANY of the popular electronic ignition systems on the
market. Dual p-mags offers the same or better suit
of features as the certified LASAR system. There are
lots of folks flying with varied combinations of mags/
electronic+mags/all-electronic variants and each owner
operator is willing to expound at length on the rationale
for his/her decision.
Bottom line is that when I walk up to a certified rental,
concerns for reliability of that machine's ignition
systems is the furthest thing from my mind. Do what makes
sense to your pocketbook and space/weight budget for
your project. The debate on suitability of one configuration
over another will go on for decades, you need to finish
your airplane SOONER.
Bob . . .
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> metrics |
| Subject: | Engine cooling modifications was RE: electronics vs. |
mags
metrics
>Alex,
Thanks for the fuel flow charts. I noticed while browsing your site, that
you have tried to fair in the lumps and bumps at the rear of your engine
compartment. I hope to do the same on my 8A project. Could you email me
higher resolution photos of the mods you've made? Have you noticed any
improvement in drag or engine cooling as a result?
Charlie Kuss
>Bob, I have done some very basic work posted here:
>
>http://www.home.earthlink.net/~alexpeterson/fuelflow.htm
>
>I really need to update it, as it is somewhat understating the benefit of
>EI, partly because I ignored the fact that the engine ran rough with the
snipped
________________________________________________________________________________
| Subject: | Re: No Solenoid Wiring Scheme (diagram for your |
comments)
| From: | "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com> |
I like light. But I like safe. I think I will go with a starter
contactor with the big fuse down stream (a starter system failure cannot
take out the avionics). Then with a solid state relay for the remaining
systems. The SSR has very low hold current (will under a watt) and
still lets me isolate the battery in the event of a short in flight.
(Probably dual batteries, dual SSRs - one for critical bus, one for
other). At only a few ounces the SSR is as light as a mechanical switch
sized for the load. So my system gives more isolation and weighs in
within of a compromised system.
And yes, I plan to fly high, IFR and Night IFR in my plane. I will
revert to my C414 for serious weather flying and night over the
mountains flights. All of these mission parameters lead to a more robust
system. But for a day sport plane (like intensive aerobatics), I might
ignore some of these design features.
Dan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
gmcjetpilot(at)yahoo.com
Subject: AeroElectric-List: Re: No Solenoid Wiring Scheme (diagram for
your comments)
Dan and Jerry:
Good points:
>From: "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com>
>Dan wrote: "It seems that during service, the starter lead is an
issue - drop a
wrench against it and ground and you probably fry something."
Good point I am a big believer in protecting every thing from
inadvertent grounding. I don't like seeing big connections and battery
terminals exposed. With the traditional relay many builders leave the
studs wide open. I think this issue can be resolved by protecting
exposed connections. This is more an issue during maintenance than in
flight, but good point. As far as it taking the whole system down,
Looking at the ANL fuse it has a delay. You could use the faster acting
ANN fuse or reduce the amp rating for faster fusing. The standard SkyTec
is about 260-280 amps MAX peak. The wire wound starters are down around
200 amps. Any way you vote for the starter contactor added back. It
sounds like BIG -OLD master is something you might be willing to leave
off?
Jerry: From: "Jerry Grimmonpre" <jerry(at)mc.net>
Jerry wrote:
"How about one manual contactor to supply the starter feed. Once
the engine
is running turn off (open) the manual contactor. The hot side of
the manual
contactor can feed a circuit to a small relay for the battery
buss"
Actually based on Eric's suggestion I added an emergency shut off and
posted it. It is a manual switch which can cut off everything, like you
are talking about. The difference is it's only activated in an
emergency. I can see your idea. To start you engage the manual switch
(assume fire wall mounted and push/pull activated), start the engine and
than turn off power to the starter, than go fly. Interesting idea. I
guess if I was going to worry about the #2 wire, I would add the
electric master back into the wiring.
For me personally I am not worried about the starter wire grounding. I
think the fuse will provide an acceptable level of safety. If I was not
happy with a fused HOT #2 starter wire.
These are all great ideas. The philosophy is for a lighter, simpler
system that maintains a high level of safety and function. The standard
wiring scheme Bob's shows in aero connection, using firewall
master/starter contactors are very good, reliable and safe. However the
above idea should be as reliable or even more reliable, while having a
small weight, simplicity and efficiency advantage. The cons are......
** I think the BIG or KEY HANG UPS I am hearing are two fold:**
Worry about an after crash fire started by sparks from the long
starter wire.
Worry about an in-flight short of the #2 awg starter wire taking the
system.
The first issue, my rationalization is the only part of the system to
be HOT in a crash (provided the pilot turned the master off) is the
starter cable. So if it shorts, the fuse blows in 0.10 seconds to 1
second. What will catch on fire? Well fuel is the biggest worry to me.
As long as you turned the fuel off and aux pump the chance is small for
the spark to catch anything on fire, as long as the fuel tanks are not
compromised. Fire is not a ZERO probability with any plane or wiring.
The solution is the emergency cut off Eric suggest. This is like Jerry's
suggestion, but Eric's suggestion is to have a cut off only for
emergencies. A firewall electric shut off may be better than a standard
wiring scheme from potential spark making.
Second: Will an in-flight partial or full short take the whole
electrical system down. Clearly it will be like starting the engine with
the avionics on. The voltage will draw down to X value (8 volts?) for a
period of time until the fuse blows. A dead short with a #2 will get
your attention. My guess is it could be like turning everything off for
an instant. I guess the worst case is an intermittent short, less than
the rated fuse value, playing havoc with the radios. Worse is if you
have EFI or EI depended engine. That is why you would have to secure and
protect that big fat wire to assure that it can't happen (at least 10 to
the 99 power chance).
My thinking about "Electrics Light" has evolved. I think is makes
sense and is most suitable for day/night VFR, with engines not electric
dependent. If you are IFR with all electric flight instruments or have
an electrical dependendant engine, the greater electrical dependency
calls for more "ISOLATION" and redundancy clearly. However I think with
careful routing and securing of the #2 awg starter cable (conduit) away
from fuel (on a Lyc around front down the right side), the risk is
reduce, and post crash or in-flight failure risks are very very
unlikely. That is why we use the good wires, right.
Keep those comments coming. I am learning a lot. I see the trade offs
more clearly. It is also clear this is not a slam dunk either way.
Regards George
---------------------------------
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)earthlink.net> |
| Subject: | Engine cooling modifications was RE: electronics |
vs. mags metrics
>
> >Alex,
>
> Thanks for the fuel flow charts. I noticed while browsing
> your site, that you have tried to fair in the lumps and bumps
> at the rear of your engine compartment. I hope to do the same
> on my 8A project. Could you email me higher resolution photos
> of the mods you've made? Have you noticed any improvement in
> drag or engine cooling as a result?
> Charlie Kuss
Charlie, I do not believe there would be any measurable speed improvements,
and any cooling improvements are hard to pin on any one thing, since truly
comparing CHT's from one flight to another is almost impossible. I only
have the firewall to belly fairing ala RV8 remaining, as I was too lazy to
put the nosegear socket fairing back on after some maintenance.
Alex Peterson
RV6-A N66AP 694 hours
Maple Grove, MN
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Garmin 300xl/KI-202 |
Good Morning OC,
Sorry for being so late in getting back, but things have been a bit hectic
for us recently.
The intent of the FAA is not always easy to discern, but I would put a
slightly different emphasis on that than do you.
They seem to write volumes and say very little. (I guess I do that as well).
Also, C-129 did have a late 2003 rewrite of which I do not have a copy, so
there may be some changes with which I am not familiar.
I have not installed an IFR GPS since the spring of 2003 so my knowledge and
discussion will concern the data available to me at that time. If
conditions have materially changed since then, I would appreciate references
thereto.
Based on a fairly extensive reading of TSO C-129 and AC-20-138, I believe
the FAA is quite clear that they intend for the operator of an IFR Approved
GPS to use only data contained within the database for IFR navigation. They
also spell out quite clearly how to determine if the data available is current
and accurate data.
In Appendix 2, Section 2, paragraph 3 of the AC 20-138 document, they
suggest the following language be placed in the FAA Approved Airplane Flight Manual
Supplement:
"IFR en route and terminal navigation is prohibited unless the pilot
verifies the currency of the data base or verifies each selected waypoint for
accuracy by reference to current approved data."
Paragraph 4 of the same section has the following suggested language:
"Instrument approaches must be accomplished from the GPS equipment data
base. The GPS equipment data base must incorporate the current update cycle".
Language identical or very close to the suggested language has been in every
FAA Approved Flight Manual Supplement that I have ever read, except for
supplements for the Apollo units that were approved after the fall of 1997.
It was at an Oshkosh "Meet The Administrator" meeting in 1996 that I first
heard of using the method of checking the data by checking publication dates
and/or the Julian date. That thought was presented to the Administrator who
said they would take it under advisement.
By the fall of 1997, Apollo had managed to convince their controlling ACO
that checking the dates met the intent of the AC-20-138 guidance.
Since each individual flight manual supplement has to be individually
approved by the local inspector via the local approval process, variances do occur.
Some of the local inspectors did not like the guidance given in AC-20-138
and insisted that any unit they approved had to have a current data base at
the time of use. The vast majority of the inspectors just used the language
that each manufacturer had used when they got the original sets approved. A
very few liked the Apollo 1997 style wording and were willing to adopt it for
sets other than the Apollo units.
I am personally aware of two folks who have King 89Bs with the Apollo
wording used in their FAA Approved Airplane Flight Manual Supplement.
The intent of the FAA, in my opinion was, and still is, that the data being
used must be current and that it must be retrieved from the database. The
pilot is NOT allowed to self load the data.
However, the FAA did provide a method whereby an out of date card could be
used if a method was available to cross check that data against other current
approved data. That provision was in the very first issue of the suggested
supplement language and is found in every supplement I have read.
While any action we take should be an action that we are willing to support
at a hearing, I think there is very good data showing that the FAA did, and
still does, allow any data available in the database to be used if it can be
shown that the data is current.
It is current data that controls the situation, not just a current data
card.
Such a provision was not considered by the FAA for the use of GPS in Lieu of
ADF and DME. For that purpose, the FAA specifically says that only data from
a current data card could be used.
I was involved in that decision.
It arose because the folks who wrote the "In Lieu Of" provisions, didn't
find out about the Apollo method until just before the "In Lieu Of" provision
was to be published. They had no gripe with the Apollo method, but that had
not been what they had told the other departments of the FAA they were going to
do. It was felt that if they went back to the rest of the FAA to change the
language previously agreed to it would take many months, quite likely a year
or more.
I will have to admit to being the guilty party who caused the problem.
The fellow who wrote the final language and was about to publish the
interpretation in the AIM asked me if I would sooner have it published with the
requirement for a current data card or wait for the self checking process to be
cleared by all responsible parties. I asked that it be published with the
restriction in the hope we could get it changed later. I was unable to develop
enough interest within the AOPA and other alphabet groups to get it changed so
that is why there is a discrepancy between what we need to do to use a GPS
in lieu of ADF and DME and what is required to fly enroute or execute an
approach.
Things are not always as simple as they should be!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
In a message dated 11/28/2005 7:41:44 A.M. Central Standard Time,
bakerocb(at)cox.net writes:
I think the intent of the FAA is very clear -- current data base is required
for IFR operations -- and that an FAA ramp check inspector, an NTSB judge,
and a jury of your peers would agree with the FAA intent. I don't think that
anything that an amateur builder of an experimental aircraft wrote in his
aircraft's AFM or supplement would convince them otherwise.
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: No Solenoid Wiring Scheme (diagram for yourcomments) |
Thanks Dan for the comments.
I agree that is another way to go and concern is understood. I would make one
comment or clarification:
"starter system failure cannot take out the avionics"
With modern starters (ones with out Bendix drives) it is almost impossible that
the starter would stick, remaining engaged or engage by itself.
What skytec says:
[I]Stuck firewall solenoids: "What about the Bendix? Maybe it stuck.
Since Sky-Tec starters do not use mechanical Bendix drives to actuate the starter,
this is actually nearly impossible for a Sky-Tec starter to keep itself engaged
with the aircraft ring gear. Sky-Tec starters are electromechanically engaged
therefore requiring voltage to engage the starter's drive pinion gear with
the ring gear. Without voltage, the pinion simply cannot remain in the flywheel.
A spring and a helical return will both force the drive pinion back out
of the ring gear and into the rest position.
If utilizing a Bendix starter, then yes, this very well may have caused the problem
(and likely did - it is a very common failure mode of starter Bendix drives).[I]
(ref http://www.skytecair.com/Cessna_Solenoids.htm)
The concern of the battery cable shorting is also an issue that you addressed
by retaining the FW starter solenoid. Other wise I think a wiring scheme that
at least omits a BIG OLD master relay altogether seems to be a very viable way
to wire the aircraft. George
>Subject: Re: No Solenoid Wiring Scheme (diagram for yourcomments)
>From: "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com>
>
>
>
>I like light. But I like safe. I think I will go with a starter
>contactor with the big fuse down stream (a starter system failure
>cannot take out the avionics).
>Dan
---------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Van's ND alternator failure |
Just took a book order from an IA in GA who is retired
from certified aviation but maintains his own airplanes
which include an RV and Glasair.
His Glasair is fitted with the B&C system. He reports
no problems with it.
Within 4 hours of installing an alternator from Van's
on the RV, he was out flying over the countryside and noted
an acid smell in the cockpit. He first assumed the odor
was from a local Kaolin plan which uses sulphuric acid
in its manufacturing processes and often smells like this.
After a few minutes, he noted that his present position was
upwind of the plant. He started looking around the panel
and noted that the voltmeter was pegged.
He reports that after shutting the alternator OFF, the
voltage dropped to levels appropriate to battery only operations
and he landed without further deterioration of the
situation.
The alternator shop said that the regulator had failed (but
obviously not in a way that prevented the pilot from
shutting it off) and had overheated the stator windings
as well. The Odyssey battery case was bulged out. No other
damage was done to the airplane's accessories
After $150 work on alternator and new battery, the system
operates normally.
He asked if there was a way to prevent this from happening
again and I gave him a brief rundown on topical conversations
that had transpired on the List over the past year. I told
him we were working on a methodology for operating the
ND and similar machines under the same design goals as
alternators in certified aircraft but that the solution was
still perhaps months off.
I sent him a copy of the original Z-24 along with operating
limitations for not operating the alternator control switch
while the alternator was loaded and at high RPMs. I don't
know if he plans to install this system as an interim fix.
Just wanted to post this additional data point for incorporation
as appropriate into future deliberations on the subject.
Bob . . .
________________________________________________________________________________
| From: | <bbradburry(at)allvantage.com> |
| Subject: | Electronics International Capacitive Fuel Level Probes |
P-300C
Does anyone know of a maker of an adapter to convert the output of these
capacitive probes to a 0-5V DC output? Or a way to do it?
Thanks,
Bill Bradburry
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: Electronics International Capacitive Fuel |
Level Probes P-300C
Bill -
Van's sells them for $45/ea. Part # IE P-300C
D
bbradburry(at)allvantage.com wrote:
>
> Does anyone know of a maker of an adapter to convert the output of these
> capacitive probes to a 0-5V DC output? Or a way to do it?
>
> Thanks,
> Bill Bradburry
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: Do I Need an Ammeter? |
Stein -
Do you have a preferred supplier of those current sensors?
D
--------
Stein Bruch wrote:
>
> Couple things....
>
> Most "glass" (assuming you're including an engine monitor) systems include
> both volts and amps, so your question may be a moot point.
>
> 2nd, a simple hall effect current sensor adds maybe 1/2 to 1 ounce and a
> wire to the plane...not overly complex or heavy, so I wouldn't worry about
> it.
>
> Plan on both Volts/Amps and then you needn't worry!
>
> Just my 2 cents as usual.
>
> Cheers,
> Stein.
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Dennis
> Johnson
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Do I Need an Ammeter?
>
>
>
>
> Greetings,
>
> I'm building a Lancair Legacy composite airplane, installing a "glass
> cockpit." I'm using the Z-13 "all electric airplane on a budget" wiring
> plan. I'll have a voltmeter, but I'm not planning to install an ammeter. I
> wonder if that's a mistake.
>
> I'll have one battery, a main alternator, and an SD8 aux alternator. Both
> alternators have overvoltage crowbar protection. The main bus has a low
> voltage warning light. I'm not planning to install an ammeter for several
> reasons: additional weight of a shunt, higher parts count, more money, and
> the temptation to do troubleshooting in flight that is better done on the
> ground. No voltmeter means I'll have to test my pitot heat by touching it
> during preflight, but other than that, is an ammeter worth the additional
> complexity, cost, and weight in my robust electrical system?
>
> Thanks,
> Dennis Johnson
> Legacy #257: finishing the engine installation and getting ready to start
> wiring
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | CardinalNSB(at)aol.com |
| Subject: | Re: Should I use shielded wire for power/ground |
Would it be appropriate to use shielded multiple wire for my power/ground?
Its already twisted (or do I need more twist)?
Its nicely bundled.
I've seen it in 16 gauge with 2 wires inside.
With 20 gauge 4 wire I could run power and a dimmer, for instance.
Would the shield help reduce noise? Should I ground the shield at either
end, or float?
Other than additional expense (and being less flexible), is there any
negatives about using shielded cable for power?
Thank you, Skip Simpson
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Engine cooling modifications |
HTML_TEXT_AFTER_BODY(at)roxy.matronics.com, BODY:,
HTML(at)roxy.matronics.com, contains(at)roxy.matronics.com,
text(at)roxy.matronics.com, after(at)roxy.matronics.com,
BODY(at)roxy.matronics.com, close(at)roxy.matronics.com,
tag(at)roxy.matronics.com
In a message dated 11/30/2005 2:58:42 A.M. Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
Thanks for the fuel flow charts. I noticed while browsing your site, that
you have tried to fair in the lumps and bumps at the rear of your engine
compartment. I hope to do the same on my 8A project. Could you email me
higher resolution photos of the mods you've made? Have you noticed any
improvement in drag or engine cooling as a result?
Charlie and Alex,
I would like to know about the engine mount fairing results, too, and I'm
interested in your plans for the mount fairings, Charlie. Do you think
fiberglas fairings could be used?
Stan Sutterfield
_www.rv-8a.net_ (http://www.rv-8a.net)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> power/ground |
| Subject: | Re: Should I use shielded wire for |
power/ground
>
>Would it be appropriate to use shielded multiple wire for my power/ground?
>Its already twisted (or do I need more twist)?
>Its nicely bundled.
>I've seen it in 16 gauge with 2 wires inside.
>With 20 gauge 4 wire I could run power and a dimmer, for instance.
>Would the shield help reduce noise? Should I ground the shield at either
>end, or float?
>
>Other than additional expense (and being less flexible), is there any
>negatives about using shielded cable for power?
Shielding has a very limited effectiveness for the reduction of
noise. Shield only those leads which are called out in the
manufacturer's installation instructions paying careful attention
to which end (if not both) is connected to a connector pin or perhaps
general system ground.
Twisting pairs is useful only when the wires pass in close proximity
to the compass . . . like within a foot for most wiring. Again,
useful to a limited degree for reducing limited kinds of interference.
Perfectly quiet systems are flying with very little shielded wire
and no twisting. To add these techniques without specific noise
issues to be fixed is a no-value-added effort.
Bob . . .
________________________________________________________________________________
| From: | <Speedy11(at)aol.com> |
| Subject: | Re: Engine cooling modifications |
"IMB Recipient 1"
In a message dated 11/30/2005 2:58:42 A.M. Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
Thanks for the fuel flow charts. I noticed while browsing your site, that
you have tried to fair in the lumps and bumps at the rear of your engine
compartment. I hope to do the same on my 8A project. Could you email me
higher resolution photos of the mods you've made? Have you noticed any
improvement in drag or engine cooling as a result?
Charlie and Alex,
I would like to know about the engine mount fairing results, too, and I'm
interested in your plans for the mount fairings, Charlie. Do you think
fiberglas fairings could be used?
Stan Sutterfield
_www.rv-8a.net_ (http://www.rv-8a.net)
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Re: Garmin 300XL and Database intent |
11/30/2005
Hello Old Bob, Thank you for your detailed and well considered comments. I
believe that some of your information may be out of date. To explain:
<>
I agree.
<>
AC20-138A dtd Dec 22, 2003 is current (available on the FAA website).
Appendix 4 is titled: "SAMPLE AIRPLANE/ROTORCRAFT FLIGHT MANUAL SUPPLEMENT"
Paragraph 3 of Section 2 LIMITATIONS reads "A valid and compatible database
must be installed and contain current data."
<< You write: "It is current data that controls the situation, not just a
current data card."
So it appears to me that you are correct if one is following AC20-138, but
that AC20-138A has a specific limitation wording recommendation that the
".... database must be installed and contain current data." I interpret that
to mean that all of the data in the data base must be current.
As a practical matter it would be very difficult for a pilot flying IFR in
IMC who was taken off his planned route to confirm that all of the data
points on his new routing were in fact accurately portrayed in his out dated
data base. And if they were not accurately portrayed he is prevented from
making manual correction entries to the data base (from what source?) per
TSO-C129a and then using those entries in IFR operations.
I much appreciate our exchange.
OC
PS: TSO-C129a dtd 2/20/1996 is currently posted on the FAA web site. Do you
know the status of the 2003 rewrite?
----- Original Message -----
From: <BobsV35B(at)aol.com>
Subject: Garmin 300XL and Database intent
> Good Morning OC,
>
> Sorry for being so late in getting back, but things have been a bit hectic
> for us recently.
>
> The intent of the FAA is not always easy to discern, but I would put a
> slightly different emphasis on that than do you.
>
> They seem to write volumes and say very little. (I guess I do that as
> well).
> Also, C-129 did have a late 2003 rewrite of which I do not have a copy,
> so
> there may be some changes with which I am not familiar.
>
> I have not installed an IFR GPS since the spring of 2003 so my knowledge
> and
> discussion will concern the data available to me at that time. If
> conditions have materially changed since then, I would appreciate
> references thereto.
> Based on a fairly extensive reading of TSO C-129 and AC-20-138, I
> believe
> the FAA is quite clear that they intend for the operator of an IFR
> Approved
> GPS to use only data contained within the database for IFR navigation.
> They
> also spell out quite clearly how to determine if the data available is
> current
> and accurate data.
>
> In Appendix 2, Section 2, paragraph 3 of the AC 20-138 document, they
> suggest the following language be placed in the FAA Approved Airplane
> Flight Manual
> Supplement:
>
> "IFR en route and terminal navigation is prohibited unless the pilot
> verifies the currency of the data base or verifies each selected waypoint
> for
> accuracy by reference to current approved data."
>
> Paragraph 4 of the same section has the following suggested language:
>
> "Instrument approaches must be accomplished from the GPS equipment data
> base. The GPS equipment data base must incorporate the current update
> cycle".
>
> Language identical or very close to the suggested language has been in
> every
> FAA Approved Flight Manual Supplement that I have ever read, except for
> supplements for the Apollo units that were approved after the fall of
> 1997.
>
> It was at an Oshkosh "Meet The Administrator" meeting in 1996 that I
> first
> heard of using the method of checking the data by checking publication
> dates
> and/or the Julian date. That thought was presented to the Administrator
> who
> said they would take it under advisement.
>
> By the fall of 1997, Apollo had managed to convince their controlling ACO
> that checking the dates met the intent of the AC-20-138 guidance.
>
> Since each individual flight manual supplement has to be individually
> approved by the local inspector via the local approval process, variances
> do occur.
> Some of the local inspectors did not like the guidance given in AC-20-138
> and insisted that any unit they approved had to have a current data base
> at
> the time of use. The vast majority of the inspectors just used the
> language
> that each manufacturer had used when they got the original sets approved.
> A
> very few liked the Apollo 1997 style wording and were willing to adopt it
> for
> sets other than the Apollo units.
>
> I am personally aware of two folks who have King 89Bs with the Apollo
> wording used in their FAA Approved Airplane Flight Manual Supplement.
>
> The intent of the FAA, in my opinion was, and still is, that the data
> being
> used must be current and that it must be retrieved from the database. The
> pilot is NOT allowed to self load the data.
>
> However, the FAA did provide a method whereby an out of date card could be
> used if a method was available to cross check that data against other
> current
> approved data. That provision was in the very first issue of the
> suggested
> supplement language and is found in every supplement I have read.
>
> While any action we take should be an action that we are willing to
> support
> at a hearing, I think there is very good data showing that the FAA did,
> and
> still does, allow any data available in the database to be used if it can
> be
> shown that the data is current.
>
> It is current data that controls the situation, not just a current data
> card.
>
> Such a provision was not considered by the FAA for the use of GPS in Lieu
> of
> ADF and DME. For that purpose, the FAA specifically says that only data
> from
> a current data card could be used.
>
> I was involved in that decision.
>
> It arose because the folks who wrote the "In Lieu Of" provisions, didn't
> find out about the Apollo method until just before the "In Lieu Of"
> provision
> was to be published. They had no gripe with the Apollo method, but that
> had
> not been what they had told the other departments of the FAA they were
> going to
> do. It was felt that if they went back to the rest of the FAA to change
> the
> language previously agreed to it would take many months, quite likely a
> year
> or more.
>
> I will have to admit to being the guilty party who caused the problem.
>
> The fellow who wrote the final language and was about to publish the
> interpretation in the AIM asked me if I would sooner have it published
> with the
> requirement for a current data card or wait for the self checking process
> to be
> cleared by all responsible parties. I asked that it be published with the
> restriction in the hope we could get it changed later. I was unable to
> develop
> enough interest within the AOPA and other alphabet groups to get it
> changed so
> that is why there is a discrepancy between what we need to do to use a
> GPS
> in lieu of ADF and DME and what is required to fly enroute or execute an
> approach.
>
> Things are not always as simple as they should be!
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Air Park LL22
> Downers Grove, IL 60516
> 630 985-8503
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Garmin 300XL and Database intent |
Good Evening OC,
The reference you give has considerably shortened the suggested language in
the Appendix. It no longer separates enroute uses from approach data.
I absolutely agree with your interpretation of the suggested language. The
next question is: Have the manufacturers changed any of the language in their
current suggested supplements?
I guess I will have to get my hands on a current copy of a Garmin
installation manual. I believe that any supplement approved prior to the date
of the
source you have provided would still be applicable to that individual
installation as the FAA has issued no guidance telling us that the approval is
not
valid.
Unfortunately, those install manuals are no longer available on the web
which makes accessing them much more difficult.
If you have any supplements that have been written since 2003, I would be
interested in knowing what they say. All of the ones I have are from 1998 or
earlier.
As to the TSO C-129 update, I find no information concerning it anywhere. I
thought I read in one of the aviation newsletters that such a modification
was made. Maybe what I saw was a reference to AC-20-138A..
In any case, my family and I have all maintained our databases with current
datacards because we wanted to be able to use the "In Lieu Of" provisions.
Thank you for the updated information.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
In a message dated 11/30/2005 10:54:38 P.M. Central Standard Time,
bakerocb(at)cox.net writes:
AC20-138A dtd Dec 22, 2003 is current (available on the FAA website).
Appendix 4 is titled: "SAMPLE AIRPLANE/ROTORCRAFT FLIGHT MANUAL SUPPLEMENT"
Paragraph 3 of Section 2 LIMITATIONS reads "A valid and compatible database
must be installed and contain current data."
________________________________________________________________________________
| From: | "Mark & Lisa" <marknlisa(at)hometel.com> |
| Subject: | Re: Garmin 300XL and Database intentGarmin 300XL and |
Database intent
OC,
While I generally agree with the most conservative opinion when it comes to
operations under IFR, I respectfully disagree with your interpretation:
> So it appears to me that you are correct
> if one is following AC20-138, but
> that AC20-138A has a specific limitation
> wording recommendation that the
> ".... database must be installed and
> contain current data." I interpret that
> to mean that all of the data in the
> data base must be current.
My interpretation is if SOME of the data is current, then the database
contains current data and meets the intent of the AC. It's up to me to
determine of the data is current before use. This allows me (and everyone
else in my situation) to continue to use my GX60 following the guidance
contained in the supplement approved when the unit was installed. I've
never received (from the FAA) a notice telling me to change the information
in the FAA-approved supplement, so I believe I'm still legal in using it, as
approved.
> As a practical matter it would be
> very difficult for a pilot flying IFR
> in IMC who was taken off his planned
> route to confirm that all of the data
> points on his new routing were in fact
> accurately portrayed in his out dated
> data base.
Actually data currency is very easily determined in a number of ways. I use
Howie Keefe's Air Chart system. I receive a cycle update every 28 days
listing all the information that's changed since the last cycle. The list
is cumulative; all changes since the first cycle of the year are on the
list. I update my database at the beginning of the update cycle, such that
my database is dated later than the date of the chart system's first update
cycle. Now I know all changed data on the update cards apply to my
database.
Prior to flight, I check all the data I plan to use. By carrying this list
in-flight I can quickly and accurately assess the validity of data I hadn't
planned to use. If data I need for a particular route is out of date, I
simply request a different route, or use the VOR. So far (3 years), I've
never NOT been able to complete a flight due to out-of-date data.
I'm meeting the intent of both the FAA and equipment manufacturer -- and my
own fairly stringent common-sense and safety requirements. And I believe
I'm making Old Bob smile, because this is exactly the result he was shooting
for!
Mark & Lisa Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
________________________________________________________________________________
| Subject: | Re: Should I use shielded wire for power/ground |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Skip -
You got the two most important reason for not using the stuff. If you need
twisted to reduce interference, you can twist wires yourself. If you are
hooking up audio (intercomm) shielded is good, as it is for magnetometers.
Stiffness is really a pain when you are trying to keep wires under control
- especially behind the panel. Stripping and keeping the shielding
relatively intact is also a pain. Bob Nuckolls has a couple of comic books
that deal with various aspects of this problem. Let me know if you can't
find them on his website and I'll send them to you.
My humble experience having just wired an ES - panel and main wiring.
John
> Other than additional expense (and being less flexible), is there any
> negatives about using shielded cable for power?
> Thank you, Skip Simpson
--
________________________________________________________________________________
| Subject: | Electronics International Capacitive Fuel Level |
Probes P-300C
| From: | "Mark R Steitle" <mark.steitle(at)austin.utexas.edu> |
Bill,
I have a Blue Mountain EFIS/1. It has two input channels for frequency
inputs. Since the EI probes have their own circuitry that reads the
capacitance and converts the values to a PWM signal, I was able to
connect the probe outputs to the EFIS/1 frequency channels and then
calibrate and I was done. When testing the capacitance fuel probes, be
sure to use gasoline, or diesel fuel as water won't work (ask me how I
know this). I've enclosed a scope shot of the pwm output signal from
the EI probe. If it gets cut, write me and I'll send it to you
directly.
If you don't have a BMA EFIS/1, all's not lost. BMA sells a converter
circuit for the EI probes that converts the signal to 0-5v DC. You can
get contact information at www.bluemountainavionics.com
Mark S.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
bbradburry(at)allvantage.com
Subject: AeroElectric-List: Electronics International Capacitive Fuel
Level Probes P-300C
Does anyone know of a maker of an adapter to convert the output of these
capacitive probes to a 0-5V DC output? Or a way to do it?
Thanks,
Bill Bradburry
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Do I Need an Ammeter? |
>
>
>Greetings,
>
>I'm building a Lancair Legacy composite airplane, installing a "glass
>cockpit." I'm using the Z-13 "all electric airplane on a budget" wiring
>plan. I'll have a voltmeter, but I'm not planning to install an
>ammeter. I wonder if that's a mistake.
>
>I'll have one battery, a main alternator, and an SD8 aux alternator. Both
>alternators have overvoltage crowbar protection. The main bus has a low
>voltage warning light. I'm not planning to install an ammeter for several
>reasons: additional weight of a shunt, higher parts count, more money,
>and the temptation to do troubleshooting in flight that is better done on
>the ground. No voltmeter means I'll have to test my pitot heat by
>touching it during preflight, but other than that, is an ammeter worth the
>additional complexity, cost, and weight in my robust electrical system?
Here's a thread on the topic that went through the List
sometime back:
>I was planning elaborate diagnostic instrumentation for my Dragonfly, with
>voltmeter test points and ammeters all over the place.
>
>Then I went flying again. While approaching my airport, I realized that if
>something hiccupped, if I saw a wisp of smoke, if a warning light went on,
>I would just not have the bandwidth to start imagining the schematic
>diagram of the electrical system and start flipping switches and taking
>voltmeter readings. I would just want to throw a switch and know that
>there is now a 2 hour countdown to landing in progress or something like
>that. The exact nature of the problem can be best diagnosed on the ground.
Absolutely . . .
>That having been said, I do think it's a good idea to plan ahead for the
>need to diagnose things on the ground and provide/label test points,
>annotate your schematic with voltage references and things like that.
> >Bob,
> >I have to disagree. His cart is not ahead of the horse. He is suggesting
> >that as we build an airplane, we build in the diagnostic equipment
> >necessary to
> >analyse the electrical system. I have to agree with that concept. And your
> >answer indicates you advocate building in diagnostic equipment as well.
> >In your final paragraph, you said doing the diagnostics on the ground
"saves
> >weight, panel space and dollars for carrying around instruments that never
> >help you fly the airplane but provides a ready access to such data for
> >diagnosis
> >when necessary." However, the sensors will be installed whether used on
the
> >ground or in the air, so no weight or money is saved. The sensors can be
> >connected for display on the engine monitor that is already going to be on
> >board,
> >so no weight or savings there.
> >I am one who likes to have as much information as I desire while
> analysing in an airborne situation.
Okay, what are your recommendations for installation of an ammeter?
What current parameter(s) are you interested in and how would you
use them in flight?
> So, I prefer to have the voltage and load at numerous
> >places throughout the electrical system. Perhaps I am so ignorant of
> >electricity that I don't even know what I'm seeing on the readings, but I
> >still want to see them.
I'm mystified by this assertion. I've had flight instructors tell
me that ALL displays on the panel are ESSENTIAL else the very wise folks
who designed and/or regulated the configuration of the airplane
would not have included them on the panel. The same instructors
could not describe how an ammeter or voltmeter was used to enhance
probability of a sweat-free arrival with the earth that was
any more illuminating than having a low voltage warning light
telling me to switch to plan-B or plan-C.
> >So, if that is our desire, rather than trying to convince us that we don't
> >need the information displayed, how about helping us determine the best
> >methods
> >to achieve our goals - that is, display of desired system indications.
> >We aren't necessarily looking for a philosophical disccussion on why an
> >alternator ammeter is better or worse or more useful/less useful than a
> >battery
> >ammeter. We are simply asking how to accomplish what we want to achieve.
> >I don't know how much weight or cost it will add to my project to be
able to
> >monitor the electrons at the alternator, main bus, standby bus, battery
bus,
> >main battery, standby battery, etc. And I don't care - I just want to
> >know how
> >best to do it.
Okay, tell us your goals. I'll suggest that your primary goal
for the day is travel from point A to point B without breaking a
sweat. I'll further suggest that it is of no value to you as
pilot to know exactly WHY an alternator has quit, it's only
useful to know it has quit and that it's time to implement a
pre-planned, very predictable alternative such that sweat-free
arrival is assured. All the voltmeters and ammeters in the world
won't help you out if you don't have pre-planned alternatives.
If you DO have pre-planned alternatives, then the voltmeters and
ammeters are surplus to the mission while airborne.
Once you're on the ground, likelihood that ammeters and voltmeters
as-installed will reveal everything you need to zero in on
root cause of failure is remote . . . there are not enough readings
available from the rudimentary installations of such displays.
You can use an airspeed indicator to fine-tune an approach, how
do you use a voltmeter or ammeter to fine-tune endurance?
Bob . . .
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Garmin 300XL and Database intentGarmin 300XL and |
Datab...
Good Morning Mark,
I am smiling, but I am also very thankful that OC has pointed out the change
in the FAA guidance material.
I really like your interpretation of the new suggested language!
As I mentioned to OC, it is now time to see what is actually written in the
individual FAA Approved Airplane Flight Manual Supplements that have been
issued since the change to 138 was made.
There is no doubt that there are many individuals within the FAA who do feel
that there should be a currently dated data card in use, but there are still
some who agree that it is the use of current data that the FAA is actually
concerned with.
While I have never had the occasion to use an outdated card, I have always
championed that use as long as a reasonable method was available to determine
the currency of the data in use.
May I ask when your supplement was written and by whom? Also, what is the
date of the installation manual that was used for guidance during the approval
process. Since your aircraft is experimental, I would think that it would
not require an FAA approval, but that you should have a supplement that spells
out the same information as would have been used for the approval of the
supplement in a normally certificated flying machine.
Thank you for providing your insight.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
In a message dated 12/1/2005 6:56:04 A.M. Central Standard Time,
marknlisa(at)hometel.com writes:
I'm meeting the intent of both the FAA and equipment manufacturer -- and my
own fairly stringent common-sense and safety requirements. And I believe
I'm making Old Bob smile, because this is exactly the result he was shooting
for!
________________________________________________________________________________
| Subject: | Do I Need an Ammeter? |
| From: | "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com> |
You bring up a good point about how to interpret the ammeter voltmeter.
Volts show you the present health of the system - but not the endurance.
If you have 14V showing on the meter, you have an alternator running the
system and charging the battery. Fail the alternator and the volts fall
to 12, the basic output of a charged battery. As you continue to fly
with no alternator, the battery will run down. Voltage Lead acid
batteries tend to fall with their charge remaining - but it is not
linear - a half full battery shows more than 6V. And that voltage
depends on how fast you are drawing current out of it - higher loads
lower the voltage. Bottom line, it is very hard to tell the capacity
remaining in the battery based on volts. So the Volt meter is VERY good
at telling if you are on alternator or not. If not, it is not very good
at forecasting how much battery you have left. So on alternator
failure, you must use other means to determine when your radios and
instruments will fall over dead due to lack of juice....
An ammeter is a pretty good alternative, but it requires a little basic
math. I prefer ammeters that show the current into/out of the battery.
These go negative on discharge and positive on charge. My C414 has such
a system. In normal operation, the ammeter shows a small current going
into the battery. This is good - the battery is being recharged. This
current is higher right after start (I have used some energy to start
the airplane - it needs to be returned - recharged - to the battery).
Then it goes down to a low maintenance. Should the alternator(s) fail,
the battery current shows negative. Suppose is shows -50A. I have a 25
Amp Hour battery. That says I should have 25/50 or .5 hours at the
present load. (we conveniently just drop the minus sign - but the .5
hours is to discharge, not charge, accounting for the minus sign) So I
immediately shut down everything I can (heater fan, extra radio, lights
I don't need during daytime, etc....) I cut the load to 10A so I now
have 25/10 or 2.5 hours to get down. I cut that in half for my safety
factor and figure a have a good 1.25 hours to get down.
There are other style ammeter hookups - the total load style. They
always show positive - Piper seemed to like this style and my C414 also
shows information this way - The idea is that it just shows total drain
from the system - but now where it is coming from. This is measured at
the battery master buss - after the recharge point from the regulator.
The value shown can be directly applied in our formula - take the value
- say 20 amps - IF the alternator were to fail now, I would have 25/20
hours left. 1.25. I cut that in half and figure it is time to get down
now. The problem with this style ammeter is that it doesn't tell you
that the alternator has failed. I believe that this configuration
should always be coupled with a voltmeter or some other circuit to tell
that the alternator has failed.
I am a proponent of IDIOT lights for alternator failure. It is easy to
get distracted by other flying duties and miss an alternator failure.
Then, it is hard to figure out where you were when you lost it - did it
just occur (I have a full battery) or did it occur before takeoff (I may
have already used up the battery). Believe me, even with an
annunciator, I have seen people in the C414 simulator take a while to
recognize an alternator failure (or a fire for that matter) when the
work load is dialed up.
Anyway, so much for "Reading those stupid gages"
Hope it helps
Dan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: Re: AeroElectric-List: Do I Need an Ammeter?
>
>
>Greetings,
>
>I'm building a Lancair Legacy composite airplane, installing a "glass
>cockpit." I'm using the Z-13 "all electric airplane on a budget" wiring
>plan. I'll have a voltmeter, but I'm not planning to install an
>ammeter. I wonder if that's a mistake.
>
>I'll have one battery, a main alternator, and an SD8 aux alternator.
Both
>alternators have overvoltage crowbar protection. The main bus has a
low
>voltage warning light. I'm not planning to install an ammeter for
several
>reasons: additional weight of a shunt, higher parts count, more money,
>and the temptation to do troubleshooting in flight that is better done
on
>the ground. No voltmeter means I'll have to test my pitot heat by
>touching it during preflight, but other than that, is an ammeter worth
the
>additional complexity, cost, and weight in my robust electrical system?
Here's a thread on the topic that went through the List
sometime back:
>I was planning elaborate diagnostic instrumentation for my Dragonfly,
with
>voltmeter test points and ammeters all over the place.
>
>Then I went flying again. While approaching my airport, I realized
that if
>something hiccupped, if I saw a wisp of smoke, if a warning light went
on,
>I would just not have the bandwidth to start imagining the schematic
>diagram of the electrical system and start flipping switches and
taking
>voltmeter readings. I would just want to throw a switch and know that
>there is now a 2 hour countdown to landing in progress or something
like
>that. The exact nature of the problem can be best diagnosed on the
ground.
Absolutely . . .
>That having been said, I do think it's a good idea to plan ahead for
the
>need to diagnose things on the ground and provide/label test points,
>annotate your schematic with voltage references and things like that.
> >Bob,
> >I have to disagree. His cart is not ahead of the horse. He is
suggesting
> >that as we build an airplane, we build in the diagnostic equipment
> >necessary to
> >analyse the electrical system. I have to agree with that concept.
And your
> >answer indicates you advocate building in diagnostic equipment as
well.
> >In your final paragraph, you said doing the diagnostics on the
ground
"saves
> >weight, panel space and dollars for carrying around instruments that
never
> >help you fly the airplane but provides a ready access to such data
for
> >diagnosis
> >when necessary." However, the sensors will be installed whether used
on
the
> >ground or in the air, so no weight or money is saved. The sensors
can be
> >connected for display on the engine monitor that is already going to
be on
> >board,
> >so no weight or savings there.
> >I am one who likes to have as much information as I desire while
> analysing in an airborne situation.
Okay, what are your recommendations for installation of an ammeter?
What current parameter(s) are you interested in and how would you
use them in flight?
> So, I prefer to have the voltage and load at numerous
> >places throughout the electrical system. Perhaps I am so ignorant of
> >electricity that I don't even know what I'm seeing on the readings,
but I
> >still want to see them.
I'm mystified by this assertion. I've had flight instructors tell
me that ALL displays on the panel are ESSENTIAL else the very wise
folks
who designed and/or regulated the configuration of the airplane
would not have included them on the panel. The same instructors
could not describe how an ammeter or voltmeter was used to enhance
probability of a sweat-free arrival with the earth that was
any more illuminating than having a low voltage warning light
telling me to switch to plan-B or plan-C.
> >So, if that is our desire, rather than trying to convince us that we
don't
> >need the information displayed, how about helping us determine the
best
> >methods
> >to achieve our goals - that is, display of desired system
indications.
> >We aren't necessarily looking for a philosophical disccussion on why
an
> >alternator ammeter is better or worse or more useful/less useful
than a
> >battery
> >ammeter. We are simply asking how to accomplish what we want to
achieve.
> >I don't know how much weight or cost it will add to my project to be
able to
> >monitor the electrons at the alternator, main bus, standby bus,
battery
bus,
> >main battery, standby battery, etc. And I don't care - I just want
to
> >know how
> >best to do it.
Okay, tell us your goals. I'll suggest that your primary goal
for the day is travel from point A to point B without breaking a
sweat. I'll further suggest that it is of no value to you as
pilot to know exactly WHY an alternator has quit, it's only
useful to know it has quit and that it's time to implement a
pre-planned, very predictable alternative such that sweat-free
arrival is assured. All the voltmeters and ammeters in the world
won't help you out if you don't have pre-planned alternatives.
If you DO have pre-planned alternatives, then the voltmeters and
ammeters are surplus to the mission while airborne.
Once you're on the ground, likelihood that ammeters and voltmeters
as-installed will reveal everything you need to zero in on
root cause of failure is remote . . . there are not enough readings
available from the rudimentary installations of such displays.
You can use an airspeed indicator to fine-tune an approach, how
do you use a voltmeter or ammeter to fine-tune endurance?
Bob . . .
________________________________________________________________________________
| From: | John Markey <markeypilot(at)yahoo.com> |
| Subject: | Required FAA Paperwork |
Good Folks:
A friend flying a fast Glasair I recently installed a GARMIN 430-series gps.
The plane originally was approved for night IFR. The shop that did the installation
is now closed and they messed up the paperwork to the FAA. I think the foul
up is irrelevant because he doesn't need to file anyway since the plane is
experimental.
MUST he file any additional paperwork with the FAA on this change, or is he "good
to go" given the original signoff for IFR in his operating limits?
Thanks,
John Markey
Glasair IIS N661CC @ VPZ
---------------------------------
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: Electronics International Capacitive Fuel |
Level Probes P-300C
A capacitance probe installation MUST be calibrated with whatever you
will be using in the tanks! You CANNOT calibrate one with diesel fuel
and expect it to be accurate with gasoline. Presumably what Mark meant
was what I just said, but just to reinforce the concept...
Water has a dielectric constant of 80, gasoline has a dielectric
constant of approximately 2 and diesel approximately 2.2. The
dielectric constant is what controls the signal magnitude from the
probe, so you can see why you cannot use water to calibrate the probe.
Dick Tasker
Mark R Steitle wrote:
>
>Bill,
>I have a Blue Mountain EFIS/1. It has two input channels for frequency
>inputs. Since the EI probes have their own circuitry that reads the
>capacitance and converts the values to a PWM signal, I was able to
>connect the probe outputs to the EFIS/1 frequency channels and then
>calibrate and I was done. When testing the capacitance fuel probes, be
>sure to use gasoline, or diesel fuel as water won't work (ask me how I
>know this). I've enclosed a scope shot of the pwm output signal from
>the EI probe. If it gets cut, write me and I'll send it to you
>directly.
>
>If you don't have a BMA EFIS/1, all's not lost. BMA sells a converter
>circuit for the EI probes that converts the signal to 0-5v DC. You can
>get contact information at www.bluemountainavionics.com
>
>Mark S.
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>bbradburry(at)allvantage.com
>To: aeroelectric-list(at)matronics.com
>Subject: AeroElectric-List: Electronics International Capacitive Fuel
>Level Probes P-300C
>
>
>Does anyone know of a maker of an adapter to convert the output of these
>capacitive probes to a 0-5V DC output? Or a way to do it?
>
>Thanks,
>Bill Bradburry
>
>
>
>
________________________________________________________________________________
| Subject: | Electronics International Capacitive Fuel Level |
Probes P-300C
| From: | "Mark R Steitle" <mark.steitle(at)austin.utexas.edu> |
Dick,
Thank you for clarifying my last posting. I just meant to say that for
testing purposes, 1) water won't work, and 2) you can get a ballpark
idea using something other than gasoline. Also, you'll need to do a
final calibration, with the fuel you'll be burning, once you have your
system connected.
Mark S.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Richard Tasker
Subject: Re: AeroElectric-List: Electronics International Capacitive
Fuel Level Probes P-300C
A capacitance probe installation MUST be calibrated with whatever you
will be using in the tanks! You CANNOT calibrate one with diesel fuel
and expect it to be accurate with gasoline. Presumably what Mark meant
was what I just said, but just to reinforce the concept...
Water has a dielectric constant of 80, gasoline has a dielectric
constant of approximately 2 and diesel approximately 2.2. The
dielectric constant is what controls the signal magnitude from the
probe, so you can see why you cannot use water to calibrate the probe.
Dick Tasker
Mark R Steitle wrote:
>
>Bill,
>I have a Blue Mountain EFIS/1. It has two input channels for frequency
>inputs. Since the EI probes have their own circuitry that reads the
>capacitance and converts the values to a PWM signal, I was able to
>connect the probe outputs to the EFIS/1 frequency channels and then
>calibrate and I was done. When testing the capacitance fuel probes, be
>sure to use gasoline, or diesel fuel as water won't work (ask me how I
>know this). I've enclosed a scope shot of the pwm output signal from
>the EI probe. If it gets cut, write me and I'll send it to you
>directly.
>
>If you don't have a BMA EFIS/1, all's not lost. BMA sells a converter
>circuit for the EI probes that converts the signal to 0-5v DC. You can
>get contact information at www.bluemountainavionics.com
>
>Mark S.
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>bbradburry(at)allvantage.com
>To: aeroelectric-list(at)matronics.com
>Subject: AeroElectric-List: Electronics International Capacitive Fuel
>Level Probes P-300C
>
>
>Does anyone know of a maker of an adapter to convert the output of
these
>capacitive probes to a 0-5V DC output? Or a way to do it?
>
>Thanks,
>Bill Bradburry
>
>
>
>
________________________________________________________________________________
| From: | "Mark R. Supinski" <mark.supinski(at)gmail.com> |
I am implementing a Z-19 based layout for an all-electric experimental.
One area I am puzzling over is the Eng Bat switch. Specifically, I am not
implementing the Low Voltage Monitor module. Instead, I have an engine
controller which includes this functionality, and also will drive an
external lamp to flash when voltage (or many other issues) fall below a
preset value. Thus I will drive the lamp found in Z-19 from this device.
My question is: what is the point of the ON vs. AUTO setting in my case?
Looking at the schematic, it seems the only function performed in the AUTO
case is to activate the low voltage monitor?? I believe that in my case I
only need a simple on/off switch to ground the contactor -- I cannot see
what AUTO does for me in addition to this.
Am I correct, or am I missing something essential here?
Mark Supinski
________________________________________________________________________________
| From: | "Dave Morris \"BigD\"" <BigD(at)DaveMorris.com> |
| Subject: | Do I Need an Ammeter? |
The 25AH battery is probably rated 25A at 10 hours. That means it will
only put out 2.5A for 10 hours, but you can't say it will put out 50A for a
half hour unless you've verified that with the discharge graph for that
specific battery. My Panasonic LC-RD1217P is a 17AH battery that puts out
1.7A for 10 hours, but at 17A, the graph shows that it will already be dead
after a little over 30 minutes, not the full hour one might expect.
Safer would be for a single "Plan B switch" to shut down a specific group
of non-essential equipment, leaving only those loads whose currents you
have already computed or measured beforehand, so that you know exactly how
many minutes of flight time you have remaining based on a calculation you
did on the ground. Even better would be to have already measured your
battery life under that load in real time on the ground, not relying on
charts and graphs from the manufacturer.
In my case, I would have done a load test to verify that my 17AH battery
can source about 5A for 2 hours (as shown in the graph), enough to get me
on the ground. And then I make sure my total loads required to fly off
that 2 hours do not exceed 5A. And then I test the battery every year to
make sure the 5A for 2 hours still holds.
Then the only thing you need an ammeter for is to verify that you aren't
drawing more than 5A for some reason, after you flip the "Plan B Switch".
Dave Morris
At 09:53 AM 12/1/2005, you wrote:
>
>Suppose is shows -50A. I have a 25
>Amp Hour battery. That says I should have 25/50 or .5 hours at the
>present load. (we conveniently just drop the minus sign - but the .5
>hours is to discharge, not charge, accounting for the minus sign) So I
>immediately shut down everything I can (heater fan, extra radio, lights
>I don't need during daytime, etc....) I cut the load to 10A so I now
>have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>factor and figure a have a good 1.25 hours to get down.
________________________________________________________________________________
| From: | Michel RIAZUELO <mt.riazuelo(at)wanadoo.fr> |
| Subject: | With or without DYNON Internal Backup Battery ? |
Hi Bob and all,
I have been flying with my ROTAX 912 powered MCR SPORTSTER since June
2004 (250 h) and after every fly I thank Aeroelectric ....!
My electrical system is Z16 figure based (of course), I have a 2 hours
electrical range and the battery will be replaced next June !
I plan to install a DYNON D10A and analyse the Internal Backup Battery
option.
I think I do not need it.
Advices are welcome.
Cheers,
Michel RIAZUELO
________________________________________________________________________________
Battery ?
| Subject: | Re: With or without DYNON Internal Backup |
Battery ?
Bonjour Michel from L'Angleterre
> I plan to install a DYNON D10A and analyse the Internal Backup Battery
> option. I think I do not need it.
For the additional $120+ for that option I think it would be a good idea.
My reason. The Backup takes over instantly on Main Bus failure only
requiring acknowledgement with 30 seconds to continue to run on back up
Lithium Battery.
The failure of the main electrics could be a traumatic or distracting event.
The Dynon resilience is automatic and could give a vital few seconds to come
to terms with a problem.
I have the D10 with Battery in my Europa with Rotax 912.
IMHO
Salutations Cordiale
Gerry Holland
G-FIZY
________________________________________________________________________________
| Subject: | Do I Need an Ammeter? |
| From: | "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com> |
I agree with you 100%. The battery discharge curves are not linear.
However, the first poster seemed to have little understanding of the
basic use of the ammeter. Getting an understanding with a linear model
is the first step. Then you understand the non-linear discharge. (That
is why I divide the capacity by two - accounts for the non-linear
discharge). And, as you point out, you always want to load shed. A
"Critical Buss" is a great way to go to plan B.
But... for understanding anything, understand the basics, then
understand the subtleties.
I still would have the ammeter - it is a great diagnostic tool - Why did
the alternator fail (overloaded?) Is the critical bus really only
drawing 5 amps? Etc. Takes a lot of stress out of a stressful
situation.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dave
Morris "BigD"
Subject: RE: AeroElectric-List: Do I Need an Ammeter?
The 25AH battery is probably rated 25A at 10 hours. That means it will
only put out 2.5A for 10 hours, but you can't say it will put out 50A
for a
half hour unless you've verified that with the discharge graph for that
specific battery. My Panasonic LC-RD1217P is a 17AH battery that puts
out
1.7A for 10 hours, but at 17A, the graph shows that it will already be
dead
after a little over 30 minutes, not the full hour one might expect.
Safer would be for a single "Plan B switch" to shut down a specific
group
of non-essential equipment, leaving only those loads whose currents you
have already computed or measured beforehand, so that you know exactly
how
many minutes of flight time you have remaining based on a calculation
you
did on the ground. Even better would be to have already measured your
battery life under that load in real time on the ground, not relying on
charts and graphs from the manufacturer.
In my case, I would have done a load test to verify that my 17AH battery
can source about 5A for 2 hours (as shown in the graph), enough to get
me
on the ground. And then I make sure my total loads required to fly off
that 2 hours do not exceed 5A. And then I test the battery every year to
make sure the 5A for 2 hours still holds.
Then the only thing you need an ammeter for is to verify that you aren't
drawing more than 5A for some reason, after you flip the "Plan B
Switch".
Dave Morris
At 09:53 AM 12/1/2005, you wrote:
>
>Suppose is shows -50A. I have a 25
>Amp Hour battery. That says I should have 25/50 or .5 hours at the
>present load. (we conveniently just drop the minus sign - but the .5
>hours is to discharge, not charge, accounting for the minus sign) So I
>immediately shut down everything I can (heater fan, extra radio, lights
>I don't need during daytime, etc....) I cut the load to 10A so I now
>have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>factor and figure a have a good 1.25 hours to get down.
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | capacitive fuel probes in foam filled tanks? |
We're installing capacitive level probes into a semi-rigid fuel bladder
that is filled with sections of coarse 'anti-explosion' foam (like the
stuff used in racing tanks).
We've been told by one outfit that we have to cut a tunnel through the
foam for the probe because any contact with the foam will render the
probe inop. True?
I assumed the center rod and outer tube of the probe acted as capacitor
'plates' and that the fuel was the dielectric. Fuel level INSIDE the
probe (between the center rod and outer tube) changes, capacitance
changes. I don't understand how the foam comes into play.
I plan on testing it out in the shop just for kicks... but I figured I'd
ask before I start pouring gasoline on things.
Thanks for any insight!
D
________________________________________________________________________________
| From: | Paul Folbrecht <pfolbrecht(at)starkinvestments.com> |
| Subject: | Re: Do I Need an Ammeter? |
That's no problem. I'm just relieved there's no issue.
Dan Beadle wrote:
>
>I agree with you 100%. The battery discharge curves are not linear.
>However, the first poster seemed to have little understanding of the
>basic use of the ammeter. Getting an understanding with a linear model
>is the first step. Then you understand the non-linear discharge. (That
>is why I divide the capacity by two - accounts for the non-linear
>discharge). And, as you point out, you always want to load shed. A
>"Critical Buss" is a great way to go to plan B.
>
>But... for understanding anything, understand the basics, then
>understand the subtleties.
>
>I still would have the ammeter - it is a great diagnostic tool - Why did
>the alternator fail (overloaded?) Is the critical bus really only
>drawing 5 amps? Etc. Takes a lot of stress out of a stressful
>situation.
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dave
>Morris "BigD"
>To: aeroelectric-list(at)matronics.com
>Subject: RE: AeroElectric-List: Do I Need an Ammeter?
>
>
>
>The 25AH battery is probably rated 25A at 10 hours. That means it will
>only put out 2.5A for 10 hours, but you can't say it will put out 50A
>for a
>half hour unless you've verified that with the discharge graph for that
>specific battery. My Panasonic LC-RD1217P is a 17AH battery that puts
>out
>1.7A for 10 hours, but at 17A, the graph shows that it will already be
>dead
>after a little over 30 minutes, not the full hour one might expect.
>
>Safer would be for a single "Plan B switch" to shut down a specific
>group
>of non-essential equipment, leaving only those loads whose currents you
>have already computed or measured beforehand, so that you know exactly
>how
>many minutes of flight time you have remaining based on a calculation
>you
>did on the ground. Even better would be to have already measured your
>battery life under that load in real time on the ground, not relying on
>charts and graphs from the manufacturer.
>
>In my case, I would have done a load test to verify that my 17AH battery
>
>can source about 5A for 2 hours (as shown in the graph), enough to get
>me
>on the ground. And then I make sure my total loads required to fly off
>that 2 hours do not exceed 5A. And then I test the battery every year to
>
>make sure the 5A for 2 hours still holds.
>
>Then the only thing you need an ammeter for is to verify that you aren't
>
>drawing more than 5A for some reason, after you flip the "Plan B
>Switch".
>
>Dave Morris
>
>
>At 09:53 AM 12/1/2005, you wrote:
>
>
>>
>>Suppose is shows -50A. I have a 25
>>Amp Hour battery. That says I should have 25/50 or .5 hours at the
>>present load. (we conveniently just drop the minus sign - but the .5
>>hours is to discharge, not charge, accounting for the minus sign) So I
>>immediately shut down everything I can (heater fan, extra radio, lights
>>I don't need during daytime, etc....) I cut the load to 10A so I now
>>have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>>factor and figure a have a good 1.25 hours to get down.
>>
>>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
>I plan to install a DYNON D10A and analyse the Internal Backup Battery
>option.
>I think I do not need it.
>
>
>
Hi Michel and all,
I'm not closely acquainted with the Dynon, but I remember that one MCR
4S builder had trouble with the keepalive draining his battery in the
hangar. When he discovered it, the battery was dead.
In my opinion, there should be ZERO current draw when the master switch
is off.
Has this something to do with your backup battery question ?
Concerning your battery check, maybe my CBA-II battery analyser could
tell you if you really need to buy a new one ? Feel free to call at LFHH
or Grenoble ;-)
FWIW,
Amicalement,
Gilles
http://contrails.free.fr
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: capacitive fuel probes in foam filled tanks? |
They are blowing smoke. A coaxial probe like you describe measures the
capacitance just as you describe. Anything outside the probe is
essentially irrelevant.
Dick Tasker
D Wysong wrote:
>
>We're installing capacitive level probes into a semi-rigid fuel bladder
>that is filled with sections of coarse 'anti-explosion' foam (like the
>stuff used in racing tanks).
>
>We've been told by one outfit that we have to cut a tunnel through the
>foam for the probe because any contact with the foam will render the
>probe inop. True?
>
>I assumed the center rod and outer tube of the probe acted as capacitor
>'plates' and that the fuel was the dielectric. Fuel level INSIDE the
>probe (between the center rod and outer tube) changes, capacitance
>changes. I don't understand how the foam comes into play.
>
>I plan on testing it out in the shop just for kicks... but I figured I'd
>ask before I start pouring gasoline on things.
>
>Thanks for any insight!
>
>D
>
>
>
>
________________________________________________________________________________
| Subject: | With or without DYNON Internal Backup Battery |
?
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Yes but that was a faulty unit I believe. The Dynon has an internal
clock and charger for its internal battery...Like it or not this
translates into a tiny current draw (milliamps) which will easily be
maintained by your battery maintainer/charger.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Gilles Thesee
Subject: Re: AeroElectric-List: With or without DYNON Internal Backup
Battery ?
--> <Gilles.Thesee@ac-grenoble.fr>
>I plan to install a DYNON D10A and analyse the Internal Backup Battery
>option.
>I think I do not need it.
>
>
>
Hi Michel and all,
I'm not closely acquainted with the Dynon, but I remember that one MCR
4S builder had trouble with the keepalive draining his battery in the
hangar. When he discovered it, the battery was dead.
In my opinion, there should be ZERO current draw when the master switch
is off.
Has this something to do with your backup battery question ?
________________________________________________________________________________
| From: | "Bruce Gray" <Bruce(at)glasair.org> |
| Subject: | capacitive fuel probes in foam filled tanks? |
Not if it keeps the probe wet.
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Richard
Tasker
Subject: Re: AeroElectric-List: capacitive fuel probes in foam filled tanks?
They are blowing smoke. A coaxial probe like you describe measures the
capacitance just as you describe. Anything outside the probe is
essentially irrelevant.
Dick Tasker
D Wysong wrote:
>
>We're installing capacitive level probes into a semi-rigid fuel bladder
>that is filled with sections of coarse 'anti-explosion' foam (like the
>stuff used in racing tanks).
>
>We've been told by one outfit that we have to cut a tunnel through the
>foam for the probe because any contact with the foam will render the
>probe inop. True?
>
>I assumed the center rod and outer tube of the probe acted as capacitor
>'plates' and that the fuel was the dielectric. Fuel level INSIDE the
>probe (between the center rod and outer tube) changes, capacitance
>changes. I don't understand how the foam comes into play.
>
>I plan on testing it out in the shop just for kicks... but I figured I'd
>ask before I start pouring gasoline on things.
>
>Thanks for any insight!
>
>D
>
>
>
>
________________________________________________________________________________
| From: | "Mark R. Supinski" <mark.supinski(at)gmail.com> |
| Subject: | Re: Alternator terminals |
>
>
> >Thanks for the input, Bob.
> >
> >I note the comment: "If I were going to use this alternator in any
> >application..." Which gets my antenna wiggling.
> >
> >General concerns about internally regulated alternators not withstanding,
> >would you not recommend this alternator for a Z-19 based system?
>
> I have no basis to recommend it or discourage it. By "any application"
> I
> meant that if I needed to discover a way to make it work anywhere,
> I'd proceed as follows . . .
>
> Bob . . .
>
On further study, I wonder whether this alternator can be used in a Z-19
style of system. As I understand it, the "F" input is used to turn the
alternator on & off -- thus if the Crowbar detects a failed regulator, the
end result is that F shuts down & the alternator is taken offline.
Based on your analysis of the internals of my existing alternator, it seems
that there is no shutting it down short of making it stop spinning. Thus,
there is no way to prevent it eating everything on the main and engine
buses.
The only solution I can see is to introduce (another!) contactor, and
somehow use the output of the crowbar & regulator to turn the contactor
on/off.
Am I misreading the Z-19 diagram / alternator analysis?
Thanks,
Mark Supinski
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: capacitive fuel probes in foam filled tanks? |
It has to keep the space inside the probe wet. Outside is irrelevant.
Dick Tasker
Bruce Gray wrote:
>
>Not if it keeps the probe wet.
>
>Bruce
>www.glasair.org
>
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Richard
>Tasker
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: capacitive fuel probes in foam filled tanks?
>
>
>
>
>They are blowing smoke. A coaxial probe like you describe measures the
>capacitance just as you describe. Anything outside the probe is
>essentially irrelevant.
>
>Dick Tasker
>
>
________________________________________________________________________________
| Subject: | capacitive fuel probes in foam filled tanks? |
| From: | "Matt Prather" <mprather(at)spro.net> |
Is the foam conductive (metalic)? I think that's the only case that might
matter. Keeping the outside of the probe wet won't cause malfuction
(think about the tank sloshing).
My understanding is that this type of probe works because it is a coaxial
capacitor (two concentric, coductive materials). The dielectric in the
capacitor changes depending on the depth of fuel in the tube (the tank).
The gauge works by measuring the change in capacitance due to the change
in overall dielectric. Capactive coupling with material on the outside of
the probe should have little effect on its operation.
Regards,
Matt-
>
>
> Not if it keeps the probe wet.
>
> Bruce
> www.glasair.org
>
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Richard Tasker
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: capacitive fuel probes in foam filled
> tanks?
>
>
>
>
> They are blowing smoke. A coaxial probe like you describe measures the
> capacitance just as you describe. Anything outside the probe is
> essentially irrelevant.
>
> Dick Tasker
>
> D Wysong wrote:
>
>>
>>We're installing capacitive level probes into a semi-rigid fuel bladder
>> that is filled with sections of coarse 'anti-explosion' foam (like the
>> stuff used in racing tanks).
>>
>>We've been told by one outfit that we have to cut a tunnel through the
>> foam for the probe because any contact with the foam will render the
>> probe inop. True?
>>
>>I assumed the center rod and outer tube of the probe acted as capacitor
>> 'plates' and that the fuel was the dielectric. Fuel level INSIDE the
>> probe (between the center rod and outer tube) changes, capacitance
>> changes. I don't understand how the foam comes into play.
>>
>>I plan on testing it out in the shop just for kicks... but I figured
>> I'd ask before I start pouring gasoline on things.
>>
>>Thanks for any insight!
>>
>>D
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: capacitive fuel probes in foam filled tanks? |
I reckon I could test this. (?)
Fill a vial (or whatever) with gasoline and lower my probe in half way
and take a reading. Then, plug the air vent at the top of the probe and
lower the probe all the way in so that the outside fuel level is much
'deeper' than what's trapped on the inside.
If the reading doesn't change then I'm set (no foam tunnels!). If the
reading does change... well... then I'll probably curse for a while,
kick the dog, and wonder why the governing physics (as I understand
them) don't make sense.
D
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
On 1 Dec 2005, at 12:17, Michel RIAZUELO wrote:
>
>
> Hi Bob and all,
>
> I have been flying with my ROTAX 912 powered MCR SPORTSTER since June
> 2004 (250 h) and after every fly I thank Aeroelectric ....!
> My electrical system is Z16 figure based (of course), I have a 2
> hours
> electrical range and the battery will be replaced next June !
>
> I plan to install a DYNON D10A and analyse the Internal Backup Battery
> option.
> I think I do not need it.
Given the conditions under which you will fly the aircraft (day VFR,
night VFR, IFR, ?), any other installed flight instruments that don't
use electrical power, the aircraft flight characteristics and any
natural stall warning, what are the consequences if you lose
electrical power and the Dynon goes black?
Even if you have a backup battery, there are potential failure modes
where the Dynon could go black (screen failure, internal failures,
etc). If you plan to live a long time you need to be equipped so a
Dynon failure leaves you in an acceptable situation. If you have
done that, the risks from an electrical failure killing the Dynon are
acceptable. I believe the backup battery is not needed, in the
strictest sense of the definition. It might be desired, but that is
a personal preference.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
Hi Werner and all,
>
>the keepalive does recharge the internal battery and there was one
>software version with a fault there. Indeed the Dynon does use some
>50-70 mA
>
That's enough to run the battery flat within a week.
When designing our ship's circuits, the question arose about the panel
clock keepalive. I'm happy with my decision to rely on the internal
battery instead of running the keepalive from the ship's main battery.
>Can I take you also on the Battery tester just living in Switzerland
>about 80 minutes away from Grenoble and want to visit my friends from
>work, he is flying from LFLG.
>
>
>
Sure, you're welcome.
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| Subject: | Re: Electronics International Capacitive Fuel Level |
Probes P-300C
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Mark -
I had a long discussion with EI folks about the difference between their
probe and VMS's. Apparently they are the same except that VMS probes have
the electronics onternal to the probe and EI has theirs outside. The
external configuration allows much easier replacement if they go kaput. If
I recall my conversation with Princeton correctly, they said both probes
have to use the module in order to interface with BMA's EFIS/ONE.
Blue Mountain also told us that we had to have the Princeton Electronics
modules for our VMS probes to provide the proper signal format to the
EFIS/ONE. The question now for us is why, if the probes are electrically
identical, do did we have to buy the Princeton modules?
Any thoughts or insights or specifics on this proble would be most
appreciated. Wiring the modules and their cost were a bit of a challenge!.
I would most appreciate your sending me, offline, a copy of the scope
trace of the EI signal.
Thanks,
John
Lancair ES - Starting the paint process.
wrote:
>
>
> Dick,
> Thank you for clarifying my last posting. I just meant to say that for
> testing purposes, 1) water won't work, and 2) you can get a ballpark
> idea using something other than gasoline. Also, you'll need to do a
> final calibration, with the fuel you'll be burning, once you have your
> system connected.
>
> Mark S.
>
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Re: Do I Need an Ammeter? |
Dan
Congratulations.
I think I never read nothing so eloquent and educating about the use (and
need) of voltmeters and ammeters.
I was in favor of using both; now I know I'm 100% right.
Thanks
Carlos
----- Original Message -----
From: "Dan Beadle" <Dan.Beadle(at)hq.InclineSoftworks.com>
Subject: RE: AeroElectric-List: Do I Need an Ammeter?
>
>
> You bring up a good point about how to interpret the ammeter voltmeter.
>
> Volts show you the present health of the system - but not the endurance.
> If you have 14V showing on the meter, you have an alternator running the
> system and charging the battery. Fail the alternator and the volts fall
> to 12, the basic output of a charged battery. As you continue to fly
> with no alternator, the battery will run down. Voltage Lead acid
> batteries tend to fall with their charge remaining - but it is not
> linear - a half full battery shows more than 6V. And that voltage
> depends on how fast you are drawing current out of it - higher loads
> lower the voltage. Bottom line, it is very hard to tell the capacity
> remaining in the battery based on volts. So the Volt meter is VERY good
> at telling if you are on alternator or not. If not, it is not very good
> at forecasting how much battery you have left. So on alternator
> failure, you must use other means to determine when your radios and
> instruments will fall over dead due to lack of juice....
>
> An ammeter is a pretty good alternative, but it requires a little basic
> math. I prefer ammeters that show the current into/out of the battery.
> These go negative on discharge and positive on charge. My C414 has such
> a system. In normal operation, the ammeter shows a small current going
> into the battery. This is good - the battery is being recharged. This
> current is higher right after start (I have used some energy to start
> the airplane - it needs to be returned - recharged - to the battery).
> Then it goes down to a low maintenance. Should the alternator(s) fail,
> the battery current shows negative. Suppose is shows -50A. I have a 25
> Amp Hour battery. That says I should have 25/50 or .5 hours at the
> present load. (we conveniently just drop the minus sign - but the .5
> hours is to discharge, not charge, accounting for the minus sign) So I
> immediately shut down everything I can (heater fan, extra radio, lights
> I don't need during daytime, etc....) I cut the load to 10A so I now
> have 25/10 or 2.5 hours to get down. I cut that in half for my safety
> factor and figure a have a good 1.25 hours to get down.
>
> There are other style ammeter hookups - the total load style. They
> always show positive - Piper seemed to like this style and my C414 also
> shows information this way - The idea is that it just shows total drain
> from the system - but now where it is coming from. This is measured at
> the battery master buss - after the recharge point from the regulator.
> The value shown can be directly applied in our formula - take the value
> - say 20 amps - IF the alternator were to fail now, I would have 25/20
> hours left. 1.25. I cut that in half and figure it is time to get down
> now. The problem with this style ammeter is that it doesn't tell you
> that the alternator has failed. I believe that this configuration
> should always be coupled with a voltmeter or some other circuit to tell
> that the alternator has failed.
>
> I am a proponent of IDIOT lights for alternator failure. It is easy to
> get distracted by other flying duties and miss an alternator failure.
> Then, it is hard to figure out where you were when you lost it - did it
> just occur (I have a full battery) or did it occur before takeoff (I may
> have already used up the battery). Believe me, even with an
> annunciator, I have seen people in the C414 simulator take a while to
> recognize an alternator failure (or a fire for that matter) when the
> work load is dialed up.
>
>
> Anyway, so much for "Reading those stupid gages"
>
> Hope it helps
>
> Dan
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: Electronics International Capacitive Fuel |
Level Probes P-300C
Hi John -
The VMS probes contain circuitry (the "R" part of an RC circuit) that
allows them to generate a pulse train (PWM) with frequency proportional
to fuel level. You have to buy/build the signal conditioner
(frequency-to-voltage conversion) to get the DC voltage required by the
BM units. There are IC's that'll do it for you if you're interested in
rolling your own (as long as BM handles the calibration).
The other probes (Van's, EI) are capacitors. To use them with BM units
you need to complete the RC circuit (to get frequency) AND perform the
frequency-to-voltage conversion. Same thing... but different.
So, since BM wants to see a 0-5 VDC signal, both probes DO require
signal conditioning before they can be used -- but not the same sorta
signal conditioning.
D
---------
John Schroeder wrote:
>
> Mark -
>
> I had a long discussion with EI folks about the difference between their
> probe and VMS's. Apparently they are the same except that VMS probes have
> the electronics onternal to the probe and EI has theirs outside. The
> external configuration allows much easier replacement if they go kaput. If
> I recall my conversation with Princeton correctly, they said both probes
> have to use the module in order to interface with BMA's EFIS/ONE.
>
> Blue Mountain also told us that we had to have the Princeton Electronics
> modules for our VMS probes to provide the proper signal format to the
> EFIS/ONE. The question now for us is why, if the probes are electrically
> identical, do did we have to buy the Princeton modules?
>
> Any thoughts or insights or specifics on this proble would be most
> appreciated. Wiring the modules and their cost were a bit of a challenge!.
>
> I would most appreciate your sending me, offline, a copy of the scope
> trace of the EI signal.
>
> Thanks,
>
> John
> Lancair ES - Starting the paint process.
>
>
> wrote:
>
>
>>
>>
>>Dick,
>>Thank you for clarifying my last posting. I just meant to say that for
>>testing purposes, 1) water won't work, and 2) you can get a ballpark
>>idea using something other than gasoline. Also, you'll need to do a
>>final calibration, with the fuel you'll be burning, once you have your
>>system connected.
>>
>>Mark S.
>>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Electronics International Capacitive Fuel Level |
Probes P-300C
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Hello D -
As I read Mark's posting, he simply hooked up his EI probes directly to
the BMA EFIS/ONE and it works. We did what BMA suggested: bought a
Princeton Electronics module for each probe and wired its output into the
EFIS/ONE. As I read your posting, Mark should also have had to buy a
converter/conditioner.
I am still puzzled.
Thanks for your help.
John
> So, since BM wants to see a 0-5 VDC signal, both probes DO require
> signal conditioning before they can be used -- but not the same sorta
> signal conditioning.
--
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: Do I Need an Ammeter? |
Probably mentioned before.... there are single meters, that with a push
button will show both amps (current flow and direction) and buss voltage.
Who makes a good idiot light for system voltage that will indicate both high
and low alarm settings???
David
----- Original Message -----
From: "Carlos Trigo" <trigo(at)mail.telepac.pt>
Subject: Re: AeroElectric-List: Do I Need an Ammeter?
>
>
> Dan
>
> Congratulations.
> I think I never read nothing so eloquent and educating about the use (and
> need) of voltmeters and ammeters.
> I was in favor of using both; now I know I'm 100% right.
>
> Thanks
> Carlos
>
>
> ----- Original Message -----
> From: "Dan Beadle" <Dan.Beadle(at)hq.InclineSoftworks.com>
> To:
> Subject: RE: AeroElectric-List: Do I Need an Ammeter?
>
>
>>
>>
>> You bring up a good point about how to interpret the ammeter voltmeter.
>>
>> Volts show you the present health of the system - but not the endurance.
>> If you have 14V showing on the meter, you have an alternator running the
>> system and charging the battery. Fail the alternator and the volts fall
>> to 12, the basic output of a charged battery. As you continue to fly
>> with no alternator, the battery will run down. Voltage Lead acid
>> batteries tend to fall with their charge remaining - but it is not
>> linear - a half full battery shows more than 6V. And that voltage
>> depends on how fast you are drawing current out of it - higher loads
>> lower the voltage. Bottom line, it is very hard to tell the capacity
>> remaining in the battery based on volts. So the Volt meter is VERY good
>> at telling if you are on alternator or not. If not, it is not very good
>> at forecasting how much battery you have left. So on alternator
>> failure, you must use other means to determine when your radios and
>> instruments will fall over dead due to lack of juice....
>>
>> An ammeter is a pretty good alternative, but it requires a little basic
>> math. I prefer ammeters that show the current into/out of the battery.
>> These go negative on discharge and positive on charge. My C414 has such
>> a system. In normal operation, the ammeter shows a small current going
>> into the battery. This is good - the battery is being recharged. This
>> current is higher right after start (I have used some energy to start
>> the airplane - it needs to be returned - recharged - to the battery).
>> Then it goes down to a low maintenance. Should the alternator(s) fail,
>> the battery current shows negative. Suppose is shows -50A. I have a 25
>> Amp Hour battery. That says I should have 25/50 or .5 hours at the
>> present load. (we conveniently just drop the minus sign - but the .5
>> hours is to discharge, not charge, accounting for the minus sign) So I
>> immediately shut down everything I can (heater fan, extra radio, lights
>> I don't need during daytime, etc....) I cut the load to 10A so I now
>> have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>> factor and figure a have a good 1.25 hours to get down.
>>
>> There are other style ammeter hookups - the total load style. They
>> always show positive - Piper seemed to like this style and my C414 also
>> shows information this way - The idea is that it just shows total drain
>> from the system - but now where it is coming from. This is measured at
>> the battery master buss - after the recharge point from the regulator.
>> The value shown can be directly applied in our formula - take the value
>> - say 20 amps - IF the alternator were to fail now, I would have 25/20
>> hours left. 1.25. I cut that in half and figure it is time to get down
>> now. The problem with this style ammeter is that it doesn't tell you
>> that the alternator has failed. I believe that this configuration
>> should always be coupled with a voltmeter or some other circuit to tell
>> that the alternator has failed.
>>
>> I am a proponent of IDIOT lights for alternator failure. It is easy to
>> get distracted by other flying duties and miss an alternator failure.
>> Then, it is hard to figure out where you were when you lost it - did it
>> just occur (I have a full battery) or did it occur before takeoff (I may
>> have already used up the battery). Believe me, even with an
>> annunciator, I have seen people in the C414 simulator take a while to
>> recognize an alternator failure (or a fire for that matter) when the
>> work load is dialed up.
>>
>>
>> Anyway, so much for "Reading those stupid gages"
>>
>> Hope it helps
>>
>> Dan
>
>
>
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: Electronics International Capacitive Fuel |
Level Probes P-300C
Hi John -
It sounds like Mark is using frequency inputs available on the BM unit
instead of the proportional analog (0-5 VDC) inputs for his fuel level
signals.
That was a work-around for the BM units late last decade (... before the
external DC dongles were created) when folks were trying to integrate
their Vision Microsystems probes. Those probes, however, are PWM
generators.
A P-300C (EI capacitive fuel probe) won't generate a PWM signal without
additional circuitry. So... I reckon I'm puzzled, too! :-)
D
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Do I Need an Ammeter? |
>
>Probably mentioned before.... there are single meters, that with a push
>button will show both amps (current flow and direction) and buss voltage.
>
>Who makes a good idiot light for system voltage that will indicate both high
>and low alarm settings???
If you have ov protection, the conventional wisdom that you
don't need ov indication too. An ov condition trips the system
off line which generates an immediate lv condition.
However, B&C offers an OV/LV sensor in one package that I
designed for them about 15 years ago for the ultralight
market. See:
http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?6X358218
http://bandc.biz/BC207-1install.pdf
For turnkey lv warn and aux battery management see:
http://aeroelectric.com/Catalog/AEC/9005/9005.html
For DIY lv warn and aux battery management see:
http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf
http://aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html
and
http://aeroelectric.com/articles/lvwarn/9021-620.pdf
Bob . . .
________________________________________________________________________________
| From: | Fiveonepw(at)aol.com |
| Subject: | Re: Do I Need an Ammeter? |
In a message dated 12/01/2005 12:26:49 PM Central Standard Time,
mstewart(at)iss.net writes:
One recent event was I turned on my nav lights and nothing
changed on the meter. I cant see them from the cockpit and was in night
ops.
>>>
Hi Mike- just for kix&giglz ya might want to look at this:
http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=7883
A brain fart that actually came out smelling like a petunia! And no, I don't
have an ammeter, but can see where it could have some diagnostic benefits.
In my case, a LVWM, alarm on EIS4000, input voltage display on PDAs, an e-bus
and Z-11 leave me with little concern for crises in my day/nite VFR RV- those
of y'all that challenge the WX gods may think otherwise....
Mark Phillips - Columbia, TN N51PW 260 hrs
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Do I Need an Ammeter? |
>
>
>You bring up a good point about how to interpret the ammeter voltmeter.
>
>Volts show you the present health of the system - but not the endurance.
>If you have 14V showing on the meter, you have an alternator running the
>system and charging the battery. Fail the alternator and the volts fall
>to 12, the basic output of a charged battery. As you continue to fly
>with no alternator, the battery will run down. Voltage Lead acid
>batteries tend to fall with their charge remaining - but it is not
>linear - a half full battery shows more than 6V. And that voltage
>depends on how fast you are drawing current out of it - higher loads
>lower the voltage. Bottom line, it is very hard to tell the capacity
>remaining in the battery based on volts. So the Volt meter is VERY good
>at telling if you are on alternator or not. If not, it is not very good
>at forecasting how much battery you have left. So on alternator
>failure, you must use other means to determine when your radios and
>instruments will fall over dead due to lack of juice....
All true. Consider this:
The vast majority of alternator failures are either crapped cold
or ov runaway with the former taking the lead. If one chooses to
automatically mitigate the runaway condition with ov protection,
then this failure mode is covered. If the alternator is dead,
then the bus never rises above 13.0 volts and a low voltage light
will annunciate this condition.
If the alternator has failed, I'll suggest it is far better to
KNOW in advance what the battery capacity is for a switch to
Plan-B and confidence that there's sufficient juice to support
your pre-planned alt-out endurance value. I would strive to
support needed electro-whizzies for duration of fuel aboard.
Others might choose a different value. In the final analysis,
there's no practical reason why you should not be able to operate
with confidence in your pre-planed configuration.
Even if you do have a voltmeter, the best it can do is give
you a rough idea of voltage sink rate. The average stick jocky
should be not expected to observe voltmeter readings over some
period of time and then dance mathematical gyrations necessary
to integrate and predict when things quit whizzing. It's far better
to know in advance what the number is whereupon the voltmeter
becomes surplus to the task of completing the mission.
>An ammeter is a pretty good alternative, but it requires a little basic
>math. I prefer ammeters that show the current into/out of the battery.
>These go negative on discharge and positive on charge. My C414 has such
>a system. In normal operation, the ammeter shows a small current going
>into the battery. This is good - the battery is being recharged. This
>current is higher right after start (I have used some energy to start
>the airplane - it needs to be returned - recharged - to the battery).
>Then it goes down to a low maintenance. Should the alternator(s) fail,
>the battery current shows negative. Suppose is shows -50A. I have a 25
>Amp Hour battery. That says I should have 25/50 or .5 hours at the
>present load. (we conveniently just drop the minus sign - but the .5
>hours is to discharge, not charge, accounting for the minus sign) So I
>immediately shut down everything I can (heater fan, extra radio, lights
>I don't need during daytime, etc....) I cut the load to 10A so I now
>have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>factor and figure a have a good 1.25 hours to get down.
Ammeters are a terrible predictor of endurance. The methodology
you cite presumes that the battery's capacity is equal to or
greater than advertised and neglects the fact the 25 value
is correct only for the 20 hour discharge rate (in this case,
about 1.25 amps). The apparent capacity drops as loads go up
due to increased losses in the battery's internal resistance.
The astute builder will either (1) replace an inexpensive battery
annually so as to KNOW the battery's capacity or (2) do periodic
cap checks (at the planned e-bus loading) to verify the battery's
suitability for continued flight.
>There are other style ammeter hookups - the total load style. They
>always show positive - Piper seemed to like this style and my C414 also
>shows information this way - The idea is that it just shows total drain
>from the system - but now where it is coming from. This is measured at
>the battery master buss - after the recharge point from the regulator.
>The value shown can be directly applied in our formula - take the value
>- say 20 amps - IF the alternator were to fail now, I would have 25/20
>hours left. 1.25. I cut that in half and figure it is time to get down
>now. The problem with this style ammeter is that it doesn't tell you
>that the alternator has failed. I believe that this configuration
>should always be coupled with a voltmeter or some other circuit to tell
>that the alternator has failed.
>I am a proponent of IDIOT lights for alternator failure. It is easy to
>get distracted by other flying duties and miss an alternator failure.
>Then, it is hard to figure out where you were when you lost it - did it
>just occur (I have a full battery) or did it occur before takeoff (I may
>have already used up the battery). Believe me, even with an
>annunciator, I have seen people in the C414 simulator take a while to
>recognize an alternator failure (or a fire for that matter) when the
>work load is dialed up.
Absolutely. The low voltage warning light is just such an "other circuit".
Knowing the battery's capacity at the pre-determined, Plan-B endurance
loads combined with simple notification of alternator failure is
about as bullet-proof as you can get for the workload involved.
Voltmeters, ammeters, fuel gages, oil pressure gages, etc are NOT
warning devices in any sense of the word. These devices tend to
read exactly the same things they said 1,000 observations ago and
there's a psychological incentive to ignore and/or even miss
changes in their presentation.
I'm not suggesting that one should not have these capabilities
on the panel. We're bringing a new line of high-quality loadmeters
and perhaps voltmeters to the market place in a few weeks. See:
http://www.aeroelectric.com/Pictures/Instruments/Loadmeter_2.jpg
I'll only suggest that these devices are adjuncts to active
notification of low voltage combined with a knowledge
of battery capacity as it relates to e-bus loads and the
builder's pre-selected endurance goals. Instrument readings
are interesting and useful in some venues but nearly useless
when operations/maintenance are not well planned and things
under the cowl are having a bad day.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Do I Need an Ammeter? |
>
>
>I find my amp meter(In my case an amp indication of electrons being
>replaced in the battery) to be an excellent reflection of what IS
>working. One recent event was I turned on my nav lights and nothing
>changed on the meter. I cant see them from the cockpit and was in night
>ops. Shut down, change a fuse, and away I went. (don't know why it was
>blown. I suspect it was under fused with a 4 amp fuse.)
Folks should understand that only the LOADMETER (alternator output
amps) is useful for this service. A minus-zero-plus battery ammeter
will jump when a new load is added but offers no clue as to it's
magnitude. With a LOADMETER, it's possible to tell if one of the
three nav lights are burned out.
>Also in more critical situations, like IMC with potential icing, I like
>to see that when I put the Pitot Heat on, then the amp meter goes up
>appropriately. Otherwise I would never know if it is in fact working.
Which is exactly why production aircraft today have a combination of
current and pitot heat supply voltage indication like these
two illustrations.
http://www.aeroelectric.com/Pictures/Misc/CurrentSense.jpg
http://www.aeroelectric.com/PPS/DeIce/Pitot_Heat.pdf
The light shows that the power switch is ON and the reed relay
senses that current is flowing. This identical system is installed
on most of our production aircraft at RAC.
>Frankly, given the choice, Id take amps over volts as long as I had an
>alarm, which I do, that tells me when my amps are too low or too high.
Where do you set the alarm for "too low" and "too high" and
how did you arrive at these values? And would not a low voltage
warning set at 13.0 (or 26.0) volts be more indicative of the
alternator's ability to support the current system loads?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | SOS magneto vibrators? |
>
>Comments/Questions: Hello, My question is where can I get a shower of
>sparks with relay vibrator that is shown on your drawing labeled (SHOWER
>OF SPARKS VIBRATOR FOR TOGGLE SWITCH CONTROLED MAGNETOS)? Can you please
>provide a part number, manufacture etc? I plan on using this system on my RV8.
I don't supply these kinds of parts. I write texts and offer
classes on how they work. You can buy SOS vibrators from Aircraft
Spruce but be aware that Shower of Sparks diagram I've illustrated
is UNIQUE to two-breaker magnetos with no impulse coupler. The
same technique could be added to a single breaker mag with
impulse coupler . . . in fact, I belive there's a new, solid state
equivalent to the electro-mechanical vibrator called the Slickstart
See:
http://www.unisonindustries.com/pdf/marketing_literature/SlickStart%20Sure%20Start.pdf
This promises to add cranking performance on mags that rivals electronic
ignition.
Bob . . .
________________________________________________________________________________
| From: | "Bruce Gray" <Bruce(at)glasair.org> |
| Subject: | SOS magneto vibrators? |
Check with Unison (Slick) to see if they make a SOS mag for your engine. You
only need one (the left one).
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Subject: AeroElectric-List: SOS magneto vibrators?
>
>Comments/Questions: Hello, My question is where can I get a shower of
>sparks with relay vibrator that is shown on your drawing labeled (SHOWER
>OF SPARKS VIBRATOR FOR TOGGLE SWITCH CONTROLED MAGNETOS)? Can you please
>provide a part number, manufacture etc? I plan on using this system on my
RV8.
I don't supply these kinds of parts. I write texts and offer
classes on how they work. You can buy SOS vibrators from Aircraft
Spruce but be aware that Shower of Sparks diagram I've illustrated
is UNIQUE to two-breaker magnetos with no impulse coupler. The
same technique could be added to a single breaker mag with
impulse coupler . . . in fact, I belive there's a new, solid state
equivalent to the electro-mechanical vibrator called the Slickstart
See:
http://www.unisonindustries.com/pdf/marketing_literature/SlickStart%20Sure%2
0Start.pdf
This promises to add cranking performance on mags that rivals electronic
ignition.
Bob . . .
________________________________________________________________________________
| Subject: | Do I Need an Ammeter? |
| From: | "Dan Beadle" <Dan.Beadle(at)hq.inclinesoftworks.com> |
I subscribe to the "annual battery replacement" program that you
propose. You do need to know where the battery starts from. But I
disagree with the simple Plan B. If you trust the battery, due to
replacement, Plan B give you a minimum endurance. I can still do better
than that by consulting the ammeter and shutting down optional circuits.
I need position lights on Plan B (The failure may happen at night an
this is a regulatory requirement - I know - I could say PIC discretion
to dump the position lights at night - but I want o invoke that with due
consideration).
If the Plan B gives me an hour and I can shed some more load to get 2
hours, why not be able to tell what it is from the ammeter.
Finally, most loads on the circuits are over-stated - Peak Values. Use
the ammeter to see what the real loads are.
I agree that looking at the trend over time from pilot perspective is a
non-starter. Pilots are busy and time "warps".
Dan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: RE: AeroElectric-List: Do I Need an Ammeter?
>
>
>You bring up a good point about how to interpret the ammeter voltmeter.
>
>Volts show you the present health of the system - but not the
endurance.
>If you have 14V showing on the meter, you have an alternator running
the
>system and charging the battery. Fail the alternator and the volts
fall
>to 12, the basic output of a charged battery. As you continue to fly
>with no alternator, the battery will run down. Voltage Lead acid
>batteries tend to fall with their charge remaining - but it is not
>linear - a half full battery shows more than 6V. And that voltage
>depends on how fast you are drawing current out of it - higher loads
>lower the voltage. Bottom line, it is very hard to tell the capacity
>remaining in the battery based on volts. So the Volt meter is VERY
good
>at telling if you are on alternator or not. If not, it is not very
good
>at forecasting how much battery you have left. So on alternator
>failure, you must use other means to determine when your radios and
>instruments will fall over dead due to lack of juice....
All true. Consider this:
The vast majority of alternator failures are either crapped cold
or ov runaway with the former taking the lead. If one chooses to
automatically mitigate the runaway condition with ov protection,
then this failure mode is covered. If the alternator is dead,
then the bus never rises above 13.0 volts and a low voltage light
will annunciate this condition.
If the alternator has failed, I'll suggest it is far better to
KNOW in advance what the battery capacity is for a switch to
Plan-B and confidence that there's sufficient juice to support
your pre-planned alt-out endurance value. I would strive to
support needed electro-whizzies for duration of fuel aboard.
Others might choose a different value. In the final analysis,
there's no practical reason why you should not be able to operate
with confidence in your pre-planed configuration.
Even if you do have a voltmeter, the best it can do is give
you a rough idea of voltage sink rate. The average stick jocky
should be not expected to observe voltmeter readings over some
period of time and then dance mathematical gyrations necessary
to integrate and predict when things quit whizzing. It's far better
to know in advance what the number is whereupon the voltmeter
becomes surplus to the task of completing the mission.
>An ammeter is a pretty good alternative, but it requires a little basic
>math. I prefer ammeters that show the current into/out of the battery.
>These go negative on discharge and positive on charge. My C414 has
such
>a system. In normal operation, the ammeter shows a small current going
>into the battery. This is good - the battery is being recharged. This
>current is higher right after start (I have used some energy to start
>the airplane - it needs to be returned - recharged - to the battery).
>Then it goes down to a low maintenance. Should the alternator(s) fail,
>the battery current shows negative. Suppose is shows -50A. I have a
25
>Amp Hour battery. That says I should have 25/50 or .5 hours at the
>present load. (we conveniently just drop the minus sign - but the .5
>hours is to discharge, not charge, accounting for the minus sign) So I
>immediately shut down everything I can (heater fan, extra radio, lights
>I don't need during daytime, etc....) I cut the load to 10A so I now
>have 25/10 or 2.5 hours to get down. I cut that in half for my safety
>factor and figure a have a good 1.25 hours to get down.
Ammeters are a terrible predictor of endurance. The methodology
you cite presumes that the battery's capacity is equal to or
greater than advertised and neglects the fact the 25 value
is correct only for the 20 hour discharge rate (in this case,
about 1.25 amps). The apparent capacity drops as loads go up
due to increased losses in the battery's internal resistance.
The astute builder will either (1) replace an inexpensive battery
annually so as to KNOW the battery's capacity or (2) do periodic
cap checks (at the planned e-bus loading) to verify the battery's
suitability for continued flight.
>There are other style ammeter hookups - the total load style. They
>always show positive - Piper seemed to like this style and my C414 also
>shows information this way - The idea is that it just shows total drain
>from the system - but now where it is coming from. This is measured at
>the battery master buss - after the recharge point from the regulator.
>The value shown can be directly applied in our formula - take the value
>- say 20 amps - IF the alternator were to fail now, I would have 25/20
>hours left. 1.25. I cut that in half and figure it is time to get
down
>now. The problem with this style ammeter is that it doesn't tell you
>that the alternator has failed. I believe that this configuration
>should always be coupled with a voltmeter or some other circuit to tell
>that the alternator has failed.
>I am a proponent of IDIOT lights for alternator failure. It is easy to
>get distracted by other flying duties and miss an alternator failure.
>Then, it is hard to figure out where you were when you lost it - did it
>just occur (I have a full battery) or did it occur before takeoff (I
may
>have already used up the battery). Believe me, even with an
>annunciator, I have seen people in the C414 simulator take a while to
>recognize an alternator failure (or a fire for that matter) when the
>work load is dialed up.
Absolutely. The low voltage warning light is just such an "other
circuit".
Knowing the battery's capacity at the pre-determined, Plan-B
endurance
loads combined with simple notification of alternator failure is
about as bullet-proof as you can get for the workload involved.
Voltmeters, ammeters, fuel gages, oil pressure gages, etc are NOT
warning devices in any sense of the word. These devices tend to
read exactly the same things they said 1,000 observations ago and
there's a psychological incentive to ignore and/or even miss
changes in their presentation.
I'm not suggesting that one should not have these capabilities
on the panel. We're bringing a new line of high-quality loadmeters
and perhaps voltmeters to the market place in a few weeks. See:
http://www.aeroelectric.com/Pictures/Instruments/Loadmeter_2.jpg
I'll only suggest that these devices are adjuncts to active
notification of low voltage combined with a knowledge
of battery capacity as it relates to e-bus loads and the
builder's pre-selected endurance goals. Instrument readings
are interesting and useful in some venues but nearly useless
when operations/maintenance are not well planned and things
under the cowl are having a bad day.
Bob . . .
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Van's ND alternator failure |
>From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
>Subject: Van's ND alternator failure
>His Glasair is fitted with the B&C system. He reports no problems with it.
Of course there could never be a problem with a B&C product, but what does that
have to do with the issue at hand, besides a little unbiased advertisement?
Just Kidding Bob :-)
>Within 4 hours of installing an alternator from Van's on the RV, he was out
flying over the countryside and noted an acid smell in the cockpit. He first assumed
the odor was from a local Kaolin plan which uses sulphuric acid in its
manufacturing processes and often smells like this.
Did he have any other OV indications except his nose, the manufacturing plant
and the voltmeter?
>After a few minutes, he noted that his present position was upwind of the plant.
He started looking around the panel and noted that the voltmeter was pegged.
Hummmm, but no other damage to any other item? The ND alternator has an OV set
point of 18 volts. In other words if the prime voltage regulation fails is goes
to a max OV limit of 18 volts. It could be very possible that the alternator
reached this level and remained there (for quite) awhile, as your customer
and his nose cruised around the countryside.
>He reports that after shutting the alternator OFF, the voltage dropped to levels
appropriate to battery only operations and he landed without further deterioration
of the situation.
Turned it off with what? (Just curious) I assume he removed power from The IGN
wire, and that worked? Hummmmm I am surprised since when this happened or like
events happened the IGN wire became ineffective? Interesting.
>The alternator shop said that the regulator had failed (but obviously not in a
way that prevented the pilot from shutting it off) and had overheated the stator
windings as well. The Odyssey battery case was bulged out. No other damage
was done to the airplane's accessories
The Odyssey can be damaged with anything over 15 volts (per their technical literature
which states 15 volt is the MAX voltage for charging). Now I can imagine
if 18 volts was allowed to abuse the battery for a while it might protest.
Bob, this just point to the wisdom of your recommendation for a good OV/LO volt
(idiot) light on the panel.
>After $150 work on alternator and new battery, the system operates normally.
>He asked if there was a way to prevent this from happening again and I gave him
a brief rundown on topical conversations that had transpired on the List over
the past year. I told him we were working on a methodology for operating the
ND and similar machines under the same design goals as alternators in certified
aircraft but that the solution was still perhaps months off.
>I sent him a copy of the original Z-24 along with operating limitations for not
operating the alternator control switch while the alternator was loaded and
at high RPMs. I don't know if he plans to install this system as an interim fix.
That was nice of you Bob. I would love to get the failed VR. What is the chance
of that? I am not happy it happened but would love to take the thing and test
it and may be do an autopsy. Ill pay for shipping.
>Just wanted to post this additional data point for incorporation as appropriate
into future deliberations on the subject.
There was another similar event to this, just recent on another list, but the
gentleman turned the Vans alternator ON/OFF while flying just to SEE? It failed
right after he turned it back ON and it went right to a higher voltage. I dont
know if it is the brand of rebuilds Van uses or what? I do know there is several
aftermarket makers of VRs for ND alternators. I think TRANSPO is one of
the better one. I notice the same VR from one maker is $19 and another is $39.
I wonder if quantity is an issue with the parts in Vans alternator. Clearly
this is unacceptable performance and there seems to be alternators, bought from
Van's, in any issue involving a ND alternator?
Thanks for the info Bob, Regards George
>Bob . . .
---------------------------------
________________________________________________________________________________
| From: | Werner Schneider <glastar(at)gmx.net> |
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
Hello Gilles,
just talked with the guy which did the measurement I was wrong, charging
the depleted internal battery showed 50-70mA
the keepalive was around 10 mA. Sho with a fully charged battery you
should be fine for more then a month.
br Werner
Gilles Thesee wrote:
>
>Hi Werner and all,
>
>
>
>>the keepalive does recharge the internal battery and there was one
>>software version with a fault there. Indeed the Dynon does use some
>>50-70 mA
>>
>>
>>
>That's enough to run the battery flat within a week.
>When designing our ship's circuits, the question arose about the panel
>clock keepalive. I'm happy with my decision to rely on the internal
>battery instead of running the keepalive from the ship's main battery.
>
>
>
>>Can I take you also on the Battery tester just living in Switzerland
>>about 80 minutes away from Grenoble and want to visit my friends from
>>work, he is flying from LFLG.
>>
>>
>>
>>
>>
>Sure, you're welcome.
>
>Regards,
>Gilles Thesee
>Grenoble, France
>http://contrails.free.fr
>
>
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Required FAA Paperwork |
Responding to AeroElectric-List message copied below and previously posted
by: John Markey markeypilot(at)yahoo.com
<>
12/2/2005
Hello John, Short answer first. No, your friend does not have to file any
additional IFR approval paperwork with the FAA for the installation of a
Garmin 430 GPS in his Glasair amateur built experimental airplane.
To explain:
1) Your friend did not need and did not have any specific ".....orginal
signoff for IFR in his operating limitations." He did not need, and should
not have attempted to obtain, any such subsequent FAA approved sign off.
2) His Operating Limitations, which were part of his original special
airworthiness certificate issued by either an FAA or DAR inspector, should
contain words like the following from the then current version of FAA Order
8130.2_:
"After completion of phase I flight testing, unless appropriately equipped
for night and/or instrument flight in accordance with 91.205, this
aircraft is to be operated under VFR, day only."
"Aircraft instruments and equipment installed and used under 91.205 must
be inspected
and maintained in accordance with the requirements of part 91. Any
maintenance or inspection of this equipment must be recorded in the aircraft
maintenance records."
3) Those sentences are the grand sum total of IFR approval for his aircraft.
There are some other instructions in his Operating Limitations that would
apply when operating the aircraft IFR such as:
"In addition, this aircraft must be operated in accordance with applicable
air traffic and general operating rules of part 91and all additional
limitations herein prescribed under the provisions of 91.319(e)."
"When filing instrument flight rules (IFR), the experimental nature of this
aircraft must be listed in the remarks section of the flight plan."
As long as his aircraft is in compliance with his Operating Limitations and
the instructions in the current version of the AIM he is legal to fly IFR
with no further aircraft approval or paperwork from the FAA.
4) I might point out that included in the AIM for IFR GPS operations are the
requirements that the pilot comply with instructions in his AFM and AFM
supplement and pilot guides. Since your friend is in control of what is in,
or not in, his planes AFM and supplement that should present no problem.
Since the pilot guide for his Garmin GPS is published by Garmin, complying
with that guide should be no problem.
5) Common sense would require that the pilot follow some installation
guidance such as that provided in AC 20-138A and a perform a healthy dose of
VFR / VMC flight testing before attempting any IFR operations.
Please let me know if I can be of further help.
OC
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re Do I Need An Ammeter? (Hall effect is very accurate) |
Ammeter or no ammeter, I like them and my vote is to
put it on the alternator output. I don't care what the
battery "current" is, since most of the time it would read a
slight charge. If the alternator fails the volt meter is the
prime electrical measurement of interest. Really an
ammeter on the battery is not too much use in my opinion.
Given just one ammeter, how hard the alternator is working,
where all electrical power comes from when the engine's
running is more important.
HOW DOES A HALL EFFECT CURRENT SENSOR
WORK? What is the difference to a ammeter shunt? Shunts
have been around forever, where hall effect for current
measurement is fairly new.
I know the hall effect method of measuring current is a little
mysterious but it is dead nuts accurate. The term hall effect
gets misused but in this case, current sensors, they are
true hall effect devices. Magnetic fields are not as simple
to understand as Ohms law, but the physics is not difficult.
They are the preferred way to measure current with high
tech devices. Shunts do work and are dead simple but they
are old fashion. Old is not always bad, but the hall effect has
some unique advantages over the traditional way to measure
current.
Some implied that the Hall effect is not accurate or that the old
shunt method is better, that is not correct in my opinion.
The Hall effect is very accurate and not subject to extraneous
readings. Also it is lighter and has less connections than a shunt.
A shunt by its very nature produces a voltage drop across it.
Hall effect is an elegant simple device and the wire just passes
thru with no break. The down side is it may not work with a
standard ammeter (which is really a voltmeter).
Here how it works:
http://en.wikipedia.org/wiki/Hall_effect
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html
http://www.ampsense.com/HANDBOOK%204.pdf
It is a little more technical than just a shunt which is just ohms
law, where V=IR. If you know R (the shunt) you measure V
(drop across the shunt) with a little volt meter in the panel, you
know current (I=V/R). So lets say the shunt is equal to a .001
ohm resistor. So at 50 amp the voltage drop across the shunt is
50 mV. So if you have volt gage that is scaled to show 50 amps
at 50mV you have an ammeter. A digital panel meter that reads
mV will read the mV as amps digitally. With a shunt we affect
the circuit by the voltage drop. A halls effect has no affect on
the circuit.
Shunt
http://www.emproshunts.com/webstore/item.aspx?sku=MLA-50-50
http://img530.imageshack.us/img530/6522/20040416a882kz.jpg
(above from RV-9A builder)
Most stand alone amp meters still use the shunt because it is
simple, cheap and has been around since dirt. I can buy or make
a shunt for a few bucks and use a digital panel meter for another
few bucks and make my own amp meter. Using a hall effect
sensor may take a little more sophistication in the meter display
to scale or "offset" the null or zero point. However with modern
engine monitors it is easy to adjust scale of offset factors to use
a hall effect sensor. This is the wave of the present / future.
The hall effect actually uses the current in the wire and it's
effect in a magnetic field to sense current. When the current in
the wire goes thru the hall effect sensor, perpendicular to the
magnetic field in the sensor, another current is produced. Since
the hall effect device is a closed loops with the only current
being the wire passing thru it, they are not effected by outside
currents as some might think, since the magnetic field is focused
inside the sensors loop. In a word they are accurate and not
subject to interference.
Examples of hall effect sensors
http://www.ampsolution.com/AMP200,300.pdf
http://www.ampsense.com/
I played around with the hall effect on my engine monitor and
it's dead nuts accurate when tested. They are very small, light
and don't require breaks in the wire like a shunt. This is a big
advantage. Hall effect devices do work different than a shunt
and therefore a simple millivoltmeter may not work. Also if you
want to measure current in two directions you need a meter that
can "offset" the null point and add a negative sign, since the hall
effect does not reverse the output "signal" current, it only sends
the magnitude. The prime use of an ammeter is the output
from the alternator, which is in one direction only, reverse current
is not needed. If you want to measure +/- current you need to
do a little more fancy process at the meter to read it.
With microprocessor based engine monitors it's not an issue to
"program" it, to scale and read the output of the sensor. The
sensor output is just a small current relative and proportional
(linear) to the current measured, like a shunt.
The main advantage the old method has the shunt is "self
powered". The hall effect needs a 5v signal to work. As was
mentioned if you have an engine monitor you will likely use a
hall effect current sensor.
George
---------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Van's ND alternator failure |
>
> >From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
> >Subject: Van's ND alternator failure
>
> >His Glasair is fitted with the B&C system. He reports no problems with it.
>
> Of course there could never be a problem with a B&C product, but what
> does that have to do with the issue at hand, besides a little unbiased
> advertisement? Just Kidding Bob :-)
Those were his words . . . the thrust of his queries
were to help him decide whether or not I recommended
replacing a system that had just produced a problem
with one that had not.
>
>
> >Within 4 hours of installing an alternator from Van's on the RV, he
> was out flying over the countryside and noted an acid smell in the
> cockpit. He first assumed the odor was from a local Kaolin plan which
> uses sulphuric acid in its manufacturing processes and often smells like this.
>
>
> Did he have any other OV indications except his nose, the manufacturing
> plant and the voltmeter?
No . . . or if he did, it was not mentioned. This is
a simple day-vfr machine and was fitted with a minimal
panel. I think the only radios were a transponder and
a Microair transceiver. They were not damaged.
>
>
> >After a few minutes, he noted that his present position was upwind of
> the plant. He started looking around the panel and noted that the
> voltmeter was pegged.
>
> Hummmm, but no other damage to any other item? The ND alternator has an
> OV set point of 18 volts. In other words if the prime voltage regulation
> fails is goes to a max OV limit of 18 volts. It could be very possible
> that the alternator reached this level and remained there (for quite)
> awhile, as your customer and his nose cruised around the countryside.
Yup . . .
> >He reports that after shutting the alternator OFF, the voltage dropped
> to levels appropriate to battery only operations and he landed without
> further deterioration of the situation.
>
> Turned it off with what? (Just curious) I assume he removed power from
> The IGN wire, and that worked? Hummmmm I am surprised since when this
> happened or like events happened the IGN wire became ineffective? Interesting.
He was not specific . . . since this was a Van's alternator,
I assume it was wired per Van's recommendations.
> >The alternator shop said that the regulator had failed (but obviously
> not in a way that prevented the pilot from shutting it off) and had
> overheated the stator windings as well. The Odyssey battery case was
> bulged out. No other damage was done to the airplane's accessories
>
>
> The Odyssey can be damaged with anything over 15 volts (per their
> technical literature which states 15 volt is the MAX voltage for
> charging). Now I can imagine if 18 volts was allowed to abuse the battery
> for a while it might protest. Bob, this just point to the wisdom of your
> recommendation for a good OV/LO volt (idiot) light on the panel.
The certified aviation community has suggested for decades
that an "over voltage condition" is any time-magnitude that
lies above the envelope described in
http://www.aeroelectric.com/Pictures/Curves/MSTD704_28V_OV.jpg
(cut voltages in half for 14v systems)
. . . hence the selection of 16/32 as the nominal static
voltage trip points for ov protection offered by suppliers
to the certified aviation community.
While I've strongly suggested an idiot light for active
NOTIFICATION of low voltage, I'd much prefer automatic and
active RESPONSE to over voltage thus negating the value
of an ov warning light . . . if present in the system, it
would be illuminated for only milliseconds.
> >After $150 work on alternator and new battery, the system operates normally.
>
> >He asked if there was a way to prevent this from happening again and I
> gave him a brief rundown on topical conversations that had transpired on
> the List over the past year. I told him we were working on a methodology
> for operating the ND and similar machines under the same design goals as
> alternators in certified aircraft but that the solution was still perhaps
> months off.
>
> >I sent him a copy of the original Z-24 along with operating limitations
> for not operating the alternator control switch while the alternator was
> loaded and at high RPMs. I don't know if he plans to install this system
> as an interim fix.
>
>
> That was nice of you Bob. I would love to get the failed VR. What is
> the chance of that? I am not happy it happened but would love to take the
> thing and test it and may be do an autopsy. Ill pay for shipping.
My thoughts exactly. I asked about it. These events transpired a few
weeks ago and were worked in a commercial overhaul shop. Likelihood that
the trash barrels have not been emptied (assuming the technician
would know exactly which regulator came out of the problem
alternator) is somewhere between zero and none.
>
>
> >Just wanted to post this additional data point for incorporation as
> appropriate into future deliberations on the subject.
>
> There was another similar event to this, just recent on another list,
> but the gentleman turned the Vans alternator ON/OFF while flying just to
> SEE? It failed right after he turned it back ON and it went right to a
> higher voltage. I dont know if it is the brand of rebuilds Van uses or
> what? I do know there is several aftermarket makers of VRs for ND
> alternators. I think TRANSPO is one of the better one. I notice the same
> VR from one maker is $19 and another is $39. I wonder if quantity is an
> issue with the parts in Vans alternator. Clearly
> this is unacceptable performance and there seems to be alternators,
> bought from Van's, in any issue involving a ND alternator?
This underscores certified aviation's obsession with ISO,
QTP, QA manuals, TSO, PMA, etc ad nauseam. If one does not
enjoy the benefits of purchasing products from a capable
and honorable supplier, then certifications of one kind or
another must be relied on as substitutes. For folks who
ignorant of the technology, certification is all they
have . . . and sometimes it isn't enough.
Bob . . .
( There are many hypotheses in science which are wrong. )
( That's perfectly all right; they're the aperture to )
( finding out what's right. )
( -Carl Sagan- )
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Simple Audio System |
>Comments/Questions: I'm planning on having two comm radios and would like
>a simple audio panel to switch transmission between the two but also
>monitor the second. All the off the shelf audio panels seem to have much
>more than I need. Any direction would be much appreciated.
See http://aeroelectric.com/articles/Rev11/18Audio_R11.pdf
Figure 18-7 for headphone wiring, figure 18-11 for
mic/ptt wiring.
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Do I Need an Ammeter? |
>
>
>
> >Frankly, given the choice, Id take amps over volts as long as I had an
> >alarm, which I do, that tells me when my amps are too low or too high.
>
> Where do you set the alarm for "too low" and "too high" and
> how did you arrive at these values?
>
>I found that with my basic running, I pull 13 amps on my all glass
>panel. I also found that with everything on I can pull 47. So I set the
>boundaries above and below that. I arrived at these values through my
>initial flight testing. I can and do often look at the amps to confirm
>that I suspect is the draw. I have found on occasion that when the
>number shown, and the number in my head don't match, something is
>amiss(usually I have failed to do something like turn the aux pump off
>or whatever.) With a voltage number I would not get that. No matter what
>I do, 14.1v is what I see. I have alarms for the voltage too. I run
>14.1v +-.2 volts and set the alarms accordingly.
How accordingly? What are your specific setpoint values?
>My summary is that my amps tells me much more than my volts. The number
>often tells me that I have forgotten something. I suppose that this
>would not work in a complex G-V. I also suspect that I am much more in
>tuned with my current draw than most as I an all electric single engine
>piston 2 seater and I know to the amp what the number should be no
>matter What Im doing. Obviously both amps and voltage are important but
>IF I had to prioritize, Id take amps over volts as an indication of
>whats going on with my electrons.
You've accurately described the functionality of both instruments.
The point I would make is that the ammeter is a good indicator of
how much electro-stuff is turned on. You use the ammeter to raise
flags that some device not needed at the moment has been inadvertently
left on. Obviously this fits your operational protocols and design
goals. An ammeter alarm with adjustable set-points could have some
utility . . . but limited. See next point.
>====
> And would not a low voltage
> warning set at 13.0 (or 26.0) volts be more indicative of the
> alternator's ability to support the current system loads?
>Bob
>
>That I am not sure of Bob. I am not familiar with the failure modes and
>the rates as you are. Would an alternator continue to show my normal 13
>amps AND only deliver 13 volts? Beats me.
Only if the regulator's failure mode includes an ability to
simply shift the point of regulation. For example, suppose you
had a little screw on the back of the alternator that allowed
you to set the voltage regulator down to 12.8 volts. Then, yes.
The loads displayed on the ammeter would change very little while
the system voltage is too low to properly charge the battery.
Alarms on current are insufficiently discriminating to bring
all failures to a pilot's attention.
There are no common failure modes in integrated circuits or other
surface mount devices that "drift" . . . they either work or run
out into the weeds.
The way I use airplanes, I can't rely on ammeter or voltmeter
readings for operational assistance in flight. The reason
is that the rentals I use have no voltmeter and there's
a mix of
(1) Battery-ammeters with limited operational utility but
the ONLY warning offered when the readings go negative
and
(2) loadmeters with more utility but with variable significance
depending on the airplane. For folks that fly the same airplane
all the time, loadmeter readings can become a useful part of
the pilot's sense of system condition including a poor
degree of warning - a zero reading is significant.
The two conditions that all but guarantee comfortable completion
of any flight is that the voltage is above 13.0 volts (greater than a
battery-only bus) and less than 16.0 (not in a runaway
condition).
This is why I've suggested that addressing these two points
covers 99.9% of concerns about system functionality with active
notification of low volts and active response to high volts while
airborne. Adding more numbers never hurts for normal operations
but they're never enough for a full diagnostic study and
they MIGHT be a no-value-added distraction or even mis-leading
if things are not going well.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Z-19 Eng Bat |
>
>
>I am implementing a Z-19 based layout for an all-electric experimental.
>
>One area I am puzzling over is the Eng Bat switch. Specifically, I am not
>implementing the Low Voltage Monitor module. Instead, I have an engine
>controller which includes this functionality, and also will drive an
>external lamp to flash when voltage (or many other issues) fall below a
>preset value. Thus I will drive the lamp found in Z-19 from this device.
>
>My question is: what is the point of the ON vs. AUTO setting in my case?
>Looking at the schematic, it seems the only function performed in the AUTO
>case is to activate the low voltage monitor?? I believe that in my case I
>only need a simple on/off switch to ground the contactor -- I cannot see
>what AUTO does for me in addition to this.
See
http://aeroelectric.com/Catalog/AEC/9005/9005.html
The device is called a "Low Voltage Warning / Auxiliary Battery
Management Module". One has the option of using only the low volts
warning feature or adding an automatic aux battery isolation
subsequent to an alternator failure.
>Am I correct, or am I missing something essential here?
Keep in mind that the z-figures are intended to show architectures
and how some features like electronic ignition, different kinds of
alternator/regulator combinations, lv warning, etc. These individual
features can be mixed/matched between the various architectures
as your needs and accessories dictate.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Do I Need an Ammeter? |
>
>
>I subscribe to the "annual battery replacement" program that you
>propose. You do need to know where the battery starts from. But I
>disagree with the simple Plan B. If you trust the battery, due to
>replacement, Plan B give you a minimum endurance. I can still do better
>than that by consulting the ammeter and shutting down optional circuits.
>I need position lights on Plan B (The failure may happen at night an
>this is a regulatory requirement - I know - I could say PIC discretion
>to dump the position lights at night - but I want o invoke that with due
>consideration).
Then your Plan-B is not a "plan" but a "suite of options".
In Chapter 17 I've suggested that when the alternator
quits, you're #1 goal is to reach airport of intended
destination without breaking a sweat. The equipment needed
to achieve this goal is a tiny fraction of total electrical
system loads and does not include exterior lighting.
Your perception of the value of position lights adds
about 6A of load (in a 14v airplane) to the battery that
might more than double the e-bus loads and cut
alternator-out endurance by more than 50%.
>If the Plan B gives me an hour and I can shed some more load to get 2
>hours, why not be able to tell what it is from the ammeter?
Because you KNOW what each device/system in your airplane
needs. If it's ON, it requires a known supply of power, if
it's OFF that value goes to zero.
There's no need to "tune" alternator-out loads based
on an ammeter reading when you have pre-planned operating
configurations backed by a battery of known performance.
>Finally, most loads on the circuits are over-stated - Peak Values. Use
>the ammeter to see what the real loads are.
Absolutely! Get measurements in the shop while you're building
your airplane. Do the load analysis to KNOW what your system
requirements are for the various failure modes. Write the "plan"
on the ground to assure an outcome as opposed to shuffling
the deck of options while airborne hoping for a good outcome.
>I agree that looking at the trend over time from pilot perspective is a
>non-starter. Pilots are busy and time "warps".
Exactly. The Plan-B/E-bus operating philosophy has been
crafted to get you to a condition where you're "cleared
to land". After that, the concrete ahead belongs to you
and you can bring back any additional accessories you
like without affecting the outcome of the flight even
if the battery finally tosses in the towel.
This idea of an endurance bus versus an essential bus
is not well understood but the differences between them
are significant. Endurance-buses are intended to prevent an
emergency from developing, an essential bus assumes you're
already IN an emergency condition. There's obvious value
for "staying ahead of the airplane" at the controls . . .
I'll suggest it's even easier to "stay ahead of the
electrical system".
Bob . . .
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: Electronics International Capacitive Fuel |
Level Probes P-300C
Ah, HA! I stand corrected, Mark. Thanks for the data! My last
statement should have read "capacitive fuel probes won't generate a PWM
signal without additional circuitry." As usual, the confusion about EI
the P-300C probes was on MY end! :-)
So, to decode it all:
-- Van's fuel probes are simple capacitors (i.e. - Van is NOT reselling
EI probes). If you need PWM output, hook the probe to the $45 dongle
from Van's. If you need 0-5 VDC proportional output, hook the probe to
a $70 dongle (purchased in pairs for $140) from BM.
-- EI and Vision Microsystems probes provide PWM output. This PWM
output can be fed into BM units via the high frequency inputs. If you
need/want 0-5 VDC proportional output instead, hook them to a $$$ dongle
from Princeton.
-- If you haven't purchased probes and want 0-5 VDC proportional output
look to Princeton or Westach.
Unless you're bolting on a turbine engine or something else that
requires the BM high freq inputs for instrumentation you should be good
to go. If all else fails, at least the solution is only a dongle away.
Thanks again for those scope traces!
D
------------
Mark R Steitle wrote:
> Hi D,
> I'm responding to you directly so I can include some screen shots of the
> output from my EI capacitive fuel probes. I sent them to John also.
>
> I was told by EI that the output was a pwm signal, so I don't understand
> your last sentence. Anyway, they do generate a signal that the BMA E/1
> can read on the frequency input channel. At least, it sure appears to
> work. I'll be able to tell for sure when I get the wings on and I'm
> able to add fuel to the tanks. The lab tests turned out positive.
>
> Mark
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of D
> Wysong
> Sent: Thursday, December 01, 2005 7:54 PM
> To: aeroelectric-list(at)matronics.com.Level.Probes.P-300C
> Subject: Re: AeroElectric-List: Electronics International Capacitive
> Fuel Level Probes P-300C
>
>
> Hi John -
>
> It sounds like Mark is using frequency inputs available on the BM unit
> instead of the proportional analog (0-5 VDC) inputs for his fuel level
> signals.
>
> That was a work-around for the BM units late last decade (... before the
>
> external DC dongles were created) when folks were trying to integrate
> their Vision Microsystems probes. Those probes, however, are PWM
> generators.
>
> A P-300C (EI capacitive fuel probe) won't generate a PWM signal without
> additional circuitry. So... I reckon I'm puzzled, too! :-)
>
> D
>
>
>
>
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Re Do I Need An Ammeter? (Hall effect is very accurate) |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi George,
Comment below:
>
> the circuit by the voltage drop. A halls effect has no affect on the
> circuit.
>
Nit to pick.. I think it's one of the fundamental principles of physics
that observing a system changes the behavior of the system. Some methods
of observation are less intrusive than others. I will admit that the hall
effect sensor intrudes very little on the system we are discussing, but I
believe it is untrue to say that a sensor has "no" effect on the system
being measured.
Regards,
Matt-
________________________________________________________________________________
| From: | "David Lloyd" <skywagon(at)charter.net> |
| Subject: | Re: Do I Need an Ammeter? |
Thanks Bob for the leads.......
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: AeroElectric-List: Do I Need an Ammeter?
>
>
>
>>
>>
>>Probably mentioned before.... there are single meters, that with a push
>>button will show both amps (current flow and direction) and buss voltage.
>>
>>Who makes a good idiot light for system voltage that will indicate both
>>high
>>and low alarm settings???
>
> If you have ov protection, the conventional wisdom that you
> don't need ov indication too. An ov condition trips the system
> off line which generates an immediate lv condition.
>
> However, B&C offers an OV/LV sensor in one package that I
> designed for them about 15 years ago for the ultralight
> market. See:
>
> http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?6X358218
>
> http://bandc.biz/BC207-1install.pdf
>
> For turnkey lv warn and aux battery management see:
>
> http://aeroelectric.com/Catalog/AEC/9005/9005.html
>
> For DIY lv warn and aux battery management see:
>
> http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf
> http://aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html
> and
> http://aeroelectric.com/articles/lvwarn/9021-620.pdf
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | Jerry2DT(at)aol.com |
List and Bob...
The guy at NAPA AV Dept. *thinks* the regulator he sold me, Echlin VR440,
interchanges with Ford VR166 per Z-11 and Bob's note 21. Would it matter if it
isn't as long as terms are wired the same?
Jerry Cochran
Wilsonville, OR
________________________________________________________________________________
| From: | Earl_Schroeder <Earl_Schroeder(at)juno.com> |
| Subject: | Re: Do I Need an Ammeter? |
David,
I guess that is one reason the B&C offers a temperature 'probe' to be
located at the battery terminal.. ;-)
Not intended to stir the pot but I use a simple indication of current
reference suggested by Jim Weir at Oshkosh many moons ago. Just install
a sensitive volt meter to read the drop across the wire from the
alternator to the bus or from the battery to the bus or use two meters
as I do. Of course it doesn't give accurate current flow [unless you
take the time to calibrate it] but does give an indication if the flow
is more or less than the reference mark you placed [on a previous normal
flight with normal stuff turned on with a FAA approved grease pencil] on
the face of the meter. I find myself glancing at it after the wheels
are tucked away each time I climb out for comparisons. Once it varied
on the high side a bit so I glanced at it more often and found comfort
when it slowly lowered to the normal mark. This was after I made more
than the normal attempts to get the 0-320 to light off so even that was
'normal'. I do have the B&C voltage reg with OV and 'idiot' light for
low voltage warning.
Earl
David Lloyd wrote:
>
>Maybe I missed part of this thread on "set" points for voltage alarming.
>My 2 cents....
>In cold weather or when the battery is down, I have seen the high charge
>voltage at 14.1 to 14.3 range as pretty normal; 14.1 as pretty close to
>ideal for cold temps.
>On a hot day or when the battery is being just carried with a charge, the
>charge level voltage is approx. 13.1 volts.
>
>
>
>
>
>
________________________________________________________________________________
| From: | SMITHBKN(at)aol.com |
| Subject: | Question on Z-35 |
Can someone with more understanding than I tell me if the auxillary battery
in the Z-35 architecture is recharged while the aircraft is operating, or in
this setup will the battery never see the alternator and thus never be
recharged while in the plane?
Jeff
________________________________________________________________________________
| From: | rv-9a-online <rv-9a-online(at)telus.net> |
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
Here's my advice on the keep alive:
I originally wired my D10A using the keep alive power connected to the
battery through a fusible link. Even with up to date software, it
discharged my main battery.
I have the internal battery, and for some reason, it continued to draw
about 100 mA, even when charged. It sounds like the software bug, but
Dynon is going to check the hardware. I also have a real time clock
problem which may be related.
The 'fix' was to disconnect the keep alive power, and run the clock on
the internal battery only. No danger of running the main battery down.
In conclusion, if you have an internal battery, do not connect the keep
alive power.
Vern Little RV-9A
Werner Schneider wrote:
>
>Hello Gilles,
>
>just talked with the guy which did the measurement I was wrong, charging
>the depleted internal battery showed 50-70mA
>the keepalive was around 10 mA. Sho with a fully charged battery you
>should be fine for more then a month.
>
>br Werner
>
>
>Gilles Thesee wrote:
>
>
>
>>
>>Hi Werner and all,
>>
>>
>>
>>
>>
>>>the keepalive does recharge the internal battery and there was one
>>>software version with a fault there. Indeed the Dynon does use some
>>>50-70 mA
>>>
>>>
>>>
>>>
>>>
>>That's enough to run the battery flat within a week.
>>When designing our ship's circuits, the question arose about the panel
>>clock keepalive. I'm happy with my decision to rely on the internal
>>battery instead of running the keepalive from the ship's main battery.
>>
>>
>>
>>
>>
>>>Can I take you also on the Battery tester just living in Switzerland
>>>about 80 minutes away from Grenoble and want to visit my friends from
>>>work, he is flying from LFLG.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>Sure, you're welcome.
>>
>>Regards,
>>Gilles Thesee
>>Grenoble, France
>>http://contrails.free.fr
>>
>>
>>
>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | "Tammy Goff" <tngoff(at)houston.rr.com> |
| Subject: | Alternator with External Regulator? |
I did a search of the aeroelectric list to see if I could find this question's
answer. I could not so:
Does anyone know of an alternator that is externally regulated (40 to 60 amp) that
will mount easily on a Lycoming O-320 E2D in a RV-6A? I have the Van's Boss
Mounts for the 60 AMP that he sells. I have his regulator too but upon close
inspection it was obvious the shipping was paid for but not the "handling."
The pulley is dented and two of the studs on the back are bent! I thought I
would see if there is any plug and play that would work with the B&C regulators
and absolve me from having to remove the IR. I made the discovery when I went
to do the IR removal on the Van's unit. I stopped without touching it and
will attempt to send it back to Van's or sell it.
Thanks George
________________________________________________________________________________
| From: | "Ron" <rondefly(at)rtriano.com> |
| Subject: | Generator question |
If I am still using the Delco 20Amp generator on my 0200 continental do I
really need the ANL60 with the brass strap? and for my ammeter should I get
a 50MV 20amp shunt and do I really need the OV protect module for a
generator? I am trying to get as close to the Z-19 drawings as I can with
the two batteries.
Thanks in advance
Ron Triano
________________________________________________________________________________
| From: | Earl_Schroeder <Earl_Schroeder(at)juno.com> |
| Subject: | Re: Alternator with External Regulator? |
Why not go to B&C and use theirs? That is what I did on a 0-320-D and
along with their reg/ov/idiot light combo makes a rock solid
installation. No problems! Earl
Tammy Goff wrote:
>
>I did a search of the aeroelectric list to see if I could find this question's
answer. I could not so:
>
>Does anyone know of an alternator that is externally regulated (40 to 60 amp)
that will mount easily on a Lycoming O-320 E2D in a RV-6A?
>
>
________________________________________________________________________________
| From: | "Wayne Sweet" <w_sweet(at)comcast.net> |
| Subject: | Re: Alternator with External Regulator? |
I agree. I have B&C alternator, battery (and backup for dual LSE CDI's),
voltage regulator and starter. Other than a field wire termial connector
breaking due to my not providing a support for the wire, it's been over 10
years with only one battery replacement. And that replaced battery sits on
my hangar floor (in a box) for 3 years STILL holding a charge (OK, I charged
it once). Why was it removed, you ask...........six years on a battery is
long enough.
Wayne
----- Original Message -----
From: "Earl_Schroeder" <Earl_Schroeder(at)juno.com>
Subject: Re: AeroElectric-List: Alternator with External Regulator?
>
>
> Why not go to B&C and use theirs? That is what I did on a 0-320-D and
> along with their reg/ov/idiot light combo makes a rock solid
> installation. No problems! Earl
>
> Tammy Goff wrote:
>
>>
>>
>>I did a search of the aeroelectric list to see if I could find this
>>question's answer. I could not so:
>>
>>Does anyone know of an alternator that is externally regulated (40 to 60
>>amp) that will mount easily on a Lycoming O-320 E2D in a RV-6A?
>>
>>
>
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Garmin 300XL and Database intent |
INNOCENT GLOBAL 0.0003 1.0000 -4.4871
Responding to an AeroElectric-List message previously posted by: "Mark &
Lisa" and copied below.
12/02/2005
Hello Mark and Lisa, I read your posting below with great interest and found
myself mostly in agreement. But a few points puzzled me -- can we pursue
them?
1) <>
If we are talking amateur built experimental aircraft here the point is moot
because the builder can write his AFM and AFM supplement to say, or not say,
what he chooses as long as it is not in direct conflict with the FAR's, the
GPS manufacturer's "pilot guide", or the AIM.
If we are talking type certificated aircraft here then it would appear that
the actual wording contained in the AFM supplement that was approved by the
FAA for that aircraft would control.
If the supplement was written back when AC 20-138 was current and the
supplement contains the sample wording provided by that AC one has
considerable data substitution leeway as described by Old Bob in his quotes
from that version of the AC.
If the supplement was written after AC 20-138A became effective and it
contains the wording from the sample in that version of the AC then one is
forced into splitting much finer hairs regarding the FAA's intent in my
opinion .
3) You wrote: "I've never received (from the FAA) a notice telling me to
change the information
in the FAA-approved supplement, so I believe I'm still legal in using it, as
approved."
I presume here that you are referring to a type certificated aircraft with
AFM supplement wording following the sample wording provided in AC 20-138. I
would agree with your position.
4) You wrote: "I update my database at the beginning of the update cycle,
such that
my database is dated later than the date of the chart system's first update
cycle. Now I know all changed data on the update cards apply to my
database."
You lost me here unless you mean that you put in a new chip, card, or
software that officially updates the entire navigation database. It is not
important that I understand, but I'll provide the following from TSO C129a
regarding Class A equipment.
"a. (3) (x) 1. The equipment shall provide an appropriately updatable
navigation data base containing at least the following location information
in terms of latitude and longitude with a resolution of 0.01 minute or
better for the area(s) in which IFR operations are to be approved: all
airports, VORs (and VORTACs), NDBs, and all named waypoints and
intersections shown on en route and terminal area charts, Standard
Instrument Departures (SIDs) and Standard Terminal Arrival Routes (STARs).
NOTE: Manual entry/update of navigation data base data shall not be
possible. (This requirement does not preclude the storage of "user defined
data" within the equipment.)"
Since I am not sure what you are doing I don't know if this pertains or not.
5) You wrote: "Prior to flight, I check all the data I plan to use. By
carrying this list
in-flight I can quickly and accurately assess the validity of data I hadn't
planned to use. If data I need for a particular route is out of date, I
simply request a different route, or use the VOR. So far (3 years), I've
never NOT been able to complete a flight due to out-of-date data."
This seems very conservative and safe to me.
6) You wrote: "I'm meeting the intent of both the FAA and equipment
manufacturer -- and my
own fairly stringent common-sense and safety requirements. And I believe
I'm making Old Bob smile, because this is exactly the result he was shooting
for!"
Anything that makes Old Bob smile is OK with me.
OC
< So it appears to me that you are correct
> if one is following AC20-138, but
> that AC20-138A has a specific limitation
> wording recommendation that the
> ".... database must be installed and
> contain current data." I interpret that
> to mean that all of the data in the
> data base must be current.
My interpretation is if SOME of the data is current, then the database
contains current data and meets the intent of the AC. It's up to me to
determine of the data is current before use. This allows me (and everyone
else in my situation) to continue to use my GX60 following the guidance
contained in the supplement approved when the unit was installed. I've
never received (from the FAA) a notice telling me to change the information
in the FAA-approved supplement, so I believe I'm still legal in using it, as
approved.
> As a practical matter it would be
> very difficult for a pilot flying IFR
> in IMC who was taken off his planned
> route to confirm that all of the data
> points on his new routing were in fact
> accurately portrayed in his out dated
> data base.
Actually data currency is very easily determined in a number of ways. I use
Howie Keefe's Air Chart system. I receive a cycle update every 28 days
listing all the information that's changed since the last cycle. The list
is cumulative; all changes since the first cycle of the year are on the
list. I update my database at the beginning of the update cycle, such that
my database is dated later than the date of the chart system's first update
cycle. Now I know all changed data on the update cards apply to my
database.
Prior to flight, I check all the data I plan to use. By carrying this list
in-flight I can quickly and accurately assess the validity of data I hadn't
planned to use. If data I need for a particular route is out of date, I
simply request a different route, or use the VOR. So far (3 years), I've
never NOT been able to complete a flight due to out-of-date data.
I'm meeting the intent of both the FAA and equipment manufacturer -- and my
own fairly stringent common-sense and safety requirements. And I believe
I'm making Old Bob smile, because this is exactly the result he was shooting
for!
Mark & Lisa Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Do I Need an Ammeter? |
In reference to voltmeters, ammeters, and loadmeters, Bob says:
I'm not suggesting that one should not have these capabilities
on the panel. We're bringing a new line of high-quality loadmeters
and perhaps voltmeters to the market place in a few weeks.
I'll only suggest that these devices are adjuncts to active
notification of low voltage combined with a knowledge
of battery capacity as it relates to e-bus loads and the
builder's pre-selected endurance goals. Instrument readings
are interesting and useful in some venues but nearly useless
when operations/maintenance are not well planned and things
under the cowl are having a bad day.
Agree wholeheartedly. Now, assuming I have a low voltage warning at, say
13.0 volts, and an OV protection scheme with associated warning light, I want to
know how and where is best to take voltage and amperage readings. Here's what
I want to know about: I want to sense amperage load at the alternator B lead
and the main battery and the standby battery. What is the appropriate
indicator to use for each of those readings (i.e., a plus-minus ammeter or a positive
indication ammeter (loadmeter?))? Do I need to also sample voltage at each
of those locations or is the voltage the same throughout the electrical circuit?
The way I understand it (from listening on this list) is that the voltage can
be measured at any location in the entire circuit and that it is the same for
the entire circuit. Amperage loads, however, will vary depending on where
the reading is taken in the circuit. So, a reading at the alternator B lead
could indicate when a new load is added to the circuit (such as pitot heat)
whereas a reading at the main or standby battery will indicate the charge or
discharge being applied to the respective battery. I would find such information
to
be, at the least, interesting.
From what I understand, an acceptable method to sample the load at any one
point in the circuit is by using a hall effect device. I understand a HE device
can only provide me with an amperage reading - no voltage.
If my understandings are convoluted, then please correct me. However, if
I've understood it correctly, then please tell me how to best obtain the desired
readings.
In advance, thanks.
Stan Sutterfield
________________________________________________________________________________
| Subject: | Re: Electronics International Capacitive Fuel Level |
Probes P-300C
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Mark & D -
Here is a quote from the BMA discussion board, followed by a reply from
Bob Northrup - their tech support guy. We were told that the EI and VM
probes were virtually identical so we had to buy the Princeton modules for
our VM probes. Using the sensor map that BMA put together, we are putting
the output of the two princeton modules into pins 11 & 12 of Analog 2 on
the EFIS/ONE. We are using the frequency channels for fuel flow and
tachometer.
Mark - It looks like you are hooking your EI probes directly to the two hi
freq channels (13 & 14) (Pins 9 & 10 of analog 2). I'll be interested in
seeing how it works and quite irked if we got a bad steer from BMA. And
being irked is also contingent on finding out that the EI and VM probes
are not equal electrically. This would make the tech people at EI appear
to be wandering in the swamp.
Anyway, since neither of us are flying yet, let's keep each other informed
as to how this problem shakes out.
Cheers,
John
===================Quote =============
mark
Guest
Posts: n/a
Did I miss it somewhere that the EI capacitance fuel probes can be hooked
to the Hi-frequency channels on the BMA, without any interface/converter
box? I have just spent many hours trying to figure out how to do this and
I stumbled across this fact almost by accident. Seems that this
information could/should have been included in the installation
instructions. What I did get (see previous posting) was the statement, "EI
probe transducers are PWM which is not supported by BMA." The EI probe
comes with a small circuit that converts the signal to PWM, so I don't
need another one, and the 0-5v PWM signal can be read by the BMA EFIS-1.
#43
07-27-2004, 10:59 PM
bob
Guest
Posts: n/a
No Mark you didn't miss anything. You can't use the high freq channels to
measure your fuel. You need freq to voltage converters that put out 0 - 5
vdc and wire to the voltage channels.
================Unquote====================
>
> Ah, HA! I stand corrected, Mark. Thanks for the data! My last
> statement should have read "capacitive fuel probes won't generate a PWM
> signal without additional circuitry." As usual, the confusion about EI
> the P-300C probes was on MY end! :-)
>
> So, to decode it all:
> -- Van's fuel probes are simple capacitors (i.e. - Van is NOT reselling
> EI probes). If you need PWM output, hook the probe to the $45 dongle
> from Van's. If you need 0-5 VDC proportional output, hook the probe to
> a $70 dongle (purchased in pairs for $140) from BM.
> -- EI and Vision Microsystems probes provide PWM output. This PWM
> output can be fed into BM units via the high frequency inputs. If you
> need/want 0-5 VDC proportional output instead, hook them to a $$$ dongle
> from Princeton.
> -- If you haven't purchased probes and want 0-5 VDC proportional output
> look to Princeton or Westach.
>
> Unless you're bolting on a turbine engine or something else that
> requires the BM high freq inputs for instrumentation you should be good
> to go. If all else fails, at least the solution is only a dongle away.
>
> Thanks again for those scope traces!
>
> D
>
> ------------
> Mark R Steitle wrote:
>> Hi D,
>> I'm responding to you directly so I can include some screen shots of the
>> output from my EI capacitive fuel probes. I sent them to John also.
>>
>> I was told by EI that the output was a pwm signal, so I don't understand
>> your last sentence. Anyway, they do generate a signal that the BMA E/1
>> can read on the frequency input channel. At least, it sure appears to
>> work. I'll be able to tell for sure when I get the wings on and I'm
>> able to add fuel to the tanks. The lab tests turned out positive.
>>
>> Mark
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of D
>> Wysong
>> Sent: Thursday, December 01, 2005 7:54 PM
>> To: aeroelectric-list(at)matronics.com.Level.Probes.P-300C
>> Subject: Re: AeroElectric-List: Electronics International Capacitive
>> Fuel Level Probes P-300C
>>
>>
>> Hi John -
>>
>> It sounds like Mark is using frequency inputs available on the BM unit
>> instead of the proportional analog (0-5 VDC) inputs for his fuel level
>> signals.
>>
>> That was a work-around for the BM units late last decade (... before the
>>
>> external DC dongles were created) when folks were trying to integrate
>> their Vision Microsystems probes. Those probes, however, are PWM
>> generators.
>>
>> A P-300C (EI capacitive fuel probe) won't generate a PWM signal without
>> additional circuitry. So... I reckon I'm puzzled, too! :-)
>>
>> D
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Question on Z-35 |
>
>Can someone with more understanding than I tell me if the auxillary battery
>in the Z-35 architecture is recharged while the aircraft is operating, or in
>this setup will the battery never see the alternator and thus never be
>recharged while in the plane?
If you close the switch, the relay closes and the battery
is supported like all other batteries in the airplane. The
switch is closed for all operations after the engine starts
and just after shutdown. The only time the switch is open
for operation is times when the alternator(s) are not available
for running system loads (and charging batteries). During this
time, the switch is open so that the aux battery is isolated
from the rest of the system and tasked with powering devices
having a higher order priority than devices on the other battery.
This philosophy is the same for all multiple battery installations
and is discussed in Chapter 17.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Do I Need an Ammeter? |
>
>
>With a voltage number I would not get that. No matter what
> >I do, 14.1v is what I see. I have alarms for the voltage too. I run
> >14.1v +-.2 volts and set the alarms accordingly.
>
> How accordingly? What are your specific setpoint values?
>
> >Bob
>
>I have a high point of 14.3v, and a low of 13.9v. Neither of which I
>have seen in any normal flight condition.
These are sufficiently 'tight' to properly annunciate
an 'abnormal' condition.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Regulator VR |
>
>List and Bob...
>
>The guy at NAPA AV Dept. *thinks* the regulator he sold me, Echlin VR440,
>interchanges with Ford VR166 per Z-11 and Bob's note 21. Would it matter
>if it
>isn't as long as terms are wired the same?
Wouldn't call it an interchange. See:
http://www.rockauto.com/ref/SMP/SMPDetail2.html?VR440.jpg
while the "Ford" VR166 looks like:
http://www.aeroelectric.com/Pictures/Regulators/Ford_SS_Reg.jpg
The VR440 has 4 wires that in all probability have
functions like:
http://www.aeroelectric.com/Pictures/Regulators/Alternator_Test_1.jpg
. . . but without specific data describing the VR440
functionality, the most I could offer is "probably".
VR166 regulators are common and plentiful. See:
http://www.sherco-auto.com/Merchant2/merchant.mvc?Session_ID=088ff92644653b316e0c97d6f1c9ce36&Screen=PROD&Product_Code=VR166
http://www.rockauto.com/ref/SMP/SMPDetail2.html?VR166.jpg
This product crosses to a variety of other drop in replacements
like these:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=8013496032&category=33577
and the GR540 and VR266 shown on
http://autolider.com.tw/acc%20parts/electrical%20%20parts/elec%20eng%20parts/REGULATORS-1.htm
So knowing nothing about the regulator he sold you and
given the prolific supply of regulators I know will work
for anything from 5 to 20 dollars, I think I'd see if
he'll take the VR440 back.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator with External Regulator? |
>
>I did a search of the aeroelectric list to see if I could find this
>question's answer. I could not so:
>
>Does anyone know of an alternator that is externally regulated (40 to 60
>amp) that will mount easily on a Lycoming O-320 E2D in a RV-6A? I have
>the Van's Boss Mounts for the 60 AMP that he sells. I have his regulator
>too but upon close inspection it was obvious the shipping was paid for but
>not the "handling." The pulley is dented and two of the studs on the back
>are bent! I thought I would see if there is any plug and play that would
>work with the B&C regulators and absolve me from having to remove the
>IR. I made the discovery when I went to do the IR removal on the Van's
>unit. I stopped without touching it and will attempt to send it back to
>Van's or sell it.
>Thanks George
B&C is the only company I'm aware of that offers
the ND alternator modified for external regulator
usage. Depending on how handy you are with the
tools and figuring things out, you might consider
modifying your own. Some articles on suggested
techniques have been cited here on the list.
Bob . . .
________________________________________________________________________________
| From: | "DonVS" <dsvs(at)comcast.net> |
| Subject: | Master Relay Mount |
Bob,
Anything new on this issue? Would you use them as delivered or would you
recommend cutting the plastic off? Thanks. Don
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert
L. Nuckolls, III
Subject: Re: AeroElectric-List: Master Relay Mount
>
>
>In a message dated 11/23/2005 10:06:58 A.M. Central Standard Time,
>rv-9a-online(at)telus.net writes:
>
>Bob, another issue with the booties is that they interfere with torquing
>the mounting bolts. They will crack before the proper torque is
>achieved. I've chucked my B&C contactors for this reason.
>
>Vern Little
>RV-9A
>
>
>Good Morning Vern,
>
>That brings up the question as to how we are determining "proper " torque?
>
>To have the attaching hardware stretched to just short of it's elastic
limit
>is one type of "torque". To squeeze a plastic such as the booties to a
>point where no creeping or cracking is another form of "proper" torque.
If
>elastic stop nuts are used for attachment of the booted device, they
>should hold
>adequately at whatever point is determined to be optimum for the subject
>fastening.
>
>The term "torque to specification" is often used without proper regard to
>what it is that we are trying to accomplish.
Exactly. When I design joints that have compressibility, I'll
call out an all metal locknut. Drive the threaded fasteners together
such that all the slack is out. Finally I'll specify some amount of
additional rotation beyond the zero-slack point where thread pitch
and rotation set the crush value.
Stancor's choice of plastic in this instance is truly mystifying.
Bob . . .
________________________________________________________________________________
| From: | Michel RIAZUELO <mt.riazuelo(at)wanadoo.fr> |
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
Thanks to all,
In France, an Exprimental Aicraft only fly day VFR. So the only thing
really important in the aircraft is the engine (not electrical dependant
!) and as long it runs, life is beautiful !
Even in day VFR (over see for instance), a good attitude indicator is a
comfortable assistant, I think the DYNON is, but my life will never be
DYNON dependant !
So, the internal backup battery seems to be useless. Furthermore it
seems to be dangerous for my 7AH HAWKER (Werner, 10 mA during a month
correspond to 7.2 AH). Its (only) 2.7 Kg (full charged) perfertly start
the ROTAX 912 and give me 2 hours of electrical autonomy.
We should suggest to DYNON a quick charging battery based system witch
runs at the beginning of flight and do not drain any current when plane
is in the hangar .....
Cheers,
Michel RIAZUELO
F-PMTR
rv-9a-online a crit :
>
>Here's my advice on the keep alive:
>
>I originally wired my D10A using the keep alive power connected to the
>battery through a fusible link. Even with up to date software, it
>discharged my main battery.
>
>I have the internal battery, and for some reason, it continued to draw
>about 100 mA, even when charged. It sounds like the software bug, but
>Dynon is going to check the hardware. I also have a real time clock
>problem which may be related.
>
>The 'fix' was to disconnect the keep alive power, and run the clock on
>the internal battery only. No danger of running the main battery down.
>
>In conclusion, if you have an internal battery, do not connect the keep
>alive power.
>
>Vern Little RV-9A
>
>
>Werner Schneider wrote:
>
>
>
>>
>>Hello Gilles,
>>
>>just talked with the guy which did the measurement I was wrong, charging
>>the depleted internal battery showed 50-70mA
>>the keepalive was around 10 mA. Sho with a fully charged battery you
>>should be fine for more then a month.
>>
>>br Werner
>>
>>
>>Gilles Thesee wrote:
>>
>>
>>
>>
>>
>>>
>>>Hi Werner and all,
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>>the keepalive does recharge the internal battery and there was one
>>>>software version with a fault there. Indeed the Dynon does use some
>>>>50-70 mA
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>That's enough to run the battery flat within a week.
>>>When designing our ship's circuits, the question arose about the panel
>>>clock keepalive. I'm happy with my decision to rely on the internal
>>>battery instead of running the keepalive from the ship's main battery.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>>Can I take you also on the Battery tester just living in Switzerland
>>>>about 80 minutes away from Grenoble and want to visit my friends from
>>>>work, he is flying from LFLG.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>Sure, you're welcome.
>>>
>>>Regards,
>>>Gilles Thesee
>>>Grenoble, France
>>>http://contrails.free.fr
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re Do I Need An Ammeter? (Hall effect is very accurate) |
OK Matt (or any one):
I'll bite, how does a hall effect current sensor affect the circuit it's measuring?
"I believe it is untrue to say that a sensor has "no" effect on the system being
measured."
Prove it?
My point nit-picky as it was, is the shunt causes a voltage drop, small as it
may be; the hall effect does not affect a voltage drop. True? Yes? No? May Be?
Angles the size of an electron dancing on the head of a pin?
The big advantage is not having a hob-glob of connectors, lugs, nuts and washers.
Hall effect: the wire slips thru, no connections. That was implied when
I said "A hall effect has no affect on the circuit", no extra connections and
no direct connection to the circuit.
"one of the fundamental principles of physics that observing a system changes
the behavior of the system."
As far as observing a system and not affecting it, I guess I was sick that day.
It has been a while since my physics class at engineering school, so I'm ready
for learn-in. I only got a C in quantum mechanics, and here is why:
"present observations can affect the way a photon behaved in the past and suggests
that even the past behavior can be determined from present. This is in
a way equivalent to changing the past."
Matt can you explain black-holes or Wormhole's? I don't believe the theory or
relativity either, until some one proves it to me. :-)
George :-)
From: "Matt Prather" <mprather(at)spro.net>
Re: AeroElectric-List: Re Do I Need An Ammeter? (Hall effect
is very accurate)
Hi George,
Comment below:
>
> the circuit by the voltage drop. A halls effect has no affect on
the circuit.
>
Nit to pick.. I think it's one of the fundamental principles of
physics that observing a system changes the behavior of the
system. Some methods of observation are less intrusive than
others. I will admit that the hall effect sensor intrudes very little
on the system we are discussing, but I believe it is untrue to
say that a sensor has "no" effect on the system being measured.
Regards,
Matt-
---------------------------------
________________________________________________________________________________
| Subject: | Re: With or without DYNON Internal Backup Battery |
?
>Basically, if you have the backup battery, you don't need the
>keep-alive wire.
>
>
That's the my conclusion about our clock battery/keep alive question two
years ago.
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Do I Need an Ammeter? |
>
>
>David,
>I guess that is one reason the B&C offers a temperature 'probe' to be
>located at the battery terminal.. ;-)
>
>Not intended to stir the pot but I use a simple indication of current
>reference suggested by Jim Weir at Oshkosh many moons ago. Just install
>a sensitive volt meter to read the drop across the wire from the
>alternator to the bus or from the battery to the bus or use two meters
>as I do. Of course it doesn't give accurate current flow [unless you
>take the time to calibrate it] but does give an indication if the flow
>is more or less than the reference mark you placed [on a previous normal
>flight with normal stuff turned on with a FAA approved grease pencil] on
>the face of the meter. I find myself glancing at it after the wheels
>are tucked away each time I climb out for comparisons. Once it varied
>on the high side a bit so I glanced at it more often and found comfort
>when it slowly lowered to the normal mark. This was after I made more
>than the normal attempts to get the 0-320 to light off so even that was
>'normal'. I do have the B&C voltage reg with OV and 'idiot' light for
>low voltage warning.
The technique cited uses the resistance of the feeder
conductors in the same manner as one would use a shunt
to deduce current flowing in a wire. Ohms law tells us that
for every amp of current flowing through 1 ohm of resistance,
we'll see 1 volt of drop. Obviously, we don't want to toss
of 1 volt/amp of supply voltage to an accessory so it's practical
and prudent to select a much smaller resistor value . . . as small
as practical commensurate with our ability to measure and display
small voltages. Over 100 years ago, folks were wrestling with
technologies compatible with their knowledge, skills, materials
and tools to measure tiny currents and indirectly, voltages.
See:
http://physics.kenyon.edu/EarlyApparatus/Electrical_Measurements/DArsonval_Galvanometer/DArsonval_Galvanometer.html
Techniques pioneered by these folks are still in place with
the best we know how to do in todays electro-mechanical
sensing and display instruments . . .
http://www.aeroelectric.com/Pictures/Instruments/Loadmeter_2.jpg
Over the years, the vast majority of resistive shunt manufacturers
and instruments designed to read voltage drops across them
settled on 50 mv as a convenient 'standard' consistent with
our ability to read and display 50 mv full scale on instruments
and the system designer's agreement that tossing off 50 mv in
appliance supply voltage was insignificant to his/her purposes
the vast majority of the time.
Obviously, to get some sense of magnitude and trends for current,
absolute calibration may not be a high priority. Having some
reasonably repeatable display of the effects of current flowing
in a wire (b-lead feeder, battery lead feeder, etc), one can
attach a suitably sensitive instrument to each end of the feeder
and get a presentation that varies in proportion to current
flow in the feeder.
If this suits your purposes as in the situation cited by
Earl above, great.
Be aware, however that calibration of systems using
copper shunts is strongly influenced by the temperature
coefficient of copper.
The Temperature Coefficient of Copper (near room temperature) is
+0.393 percent per degree C. This means if the temperature
increases 1C the resistance will increase 0.393%. Example:
You have 100 feet of 20 gauge wire and its resistance is 1.015 ohms
at 20 C (room temp). If the temperature of the wire goes up 10C
the resistance will change by 0.0399 ohms (10 degrees * 0.00393 per
degree * 1.015 ohms = 0.0399 ohms). The wire resistance will now be
1.015 ohms + 0.0399 ohms = 1.0549 ohms.
If you were using the shunt resistance of this length of copper
to deduce current flowing in it, a calibration made at room
temperature would now be off by about 4%. So we can state that
over an operating span of say -10 to +50C, calibration of
our instrument will swing over a range of approximately 25 percent.
The goals of very few measurement tasks are satisfied with such
uncertainties.
This condition placed a market requirement upon shunt manufacturers
to provide a low resistance, high current resistor that could be
calibrated very closely and manufactured from materials having very
low temperature coefficients. A metal having moderate volume resistivity
and low tempco is called manganin.
http://www.goodfellow.com/csp/active/static/A/Manganin.HTML
If one studies the configuration of the shunts illustrated
below, it's easy to differentiate the strip of manganin resistance
material mounted between heavy brass connecting posts.
http://www.aeroelectric.com/Pictures/Instruments/60-50_Shunt.jpg
http://www.aeroelectric.com/Pictures/Instruments/20-50_Shunt.jpg
http://www.aeroelectric.com/Pictures/Instruments/40-40_Shunt.jpg
The 40-40_Shunt.jpg is a 40A, 40 mV shunt sold by Vans to go
with an instrument they sell. Technically correct but incompatible
with any other shunt/instrument combinations.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Generator question |
>
>If I am still using the Delco 20Amp generator on my 0200 continental do I
>really need the ANL60 with the brass strap? and for my ammeter should I get
>a 50MV 20amp shunt and do I really need the OV protect module for a
>generator? I am trying to get as close to the Z-19 drawings as I can with
>the two batteries.
Z-19 is an architeture drawing, not a wiring diagram guaranteed
to be suited to any particular task. Yes, sizes of components
and features offered by any particular accessory need to be
tailored to your design.
The output of a 20A machine offer risk during runaway if
you have a good battery. You might want to consider an
LV/OV indication such as that offered by B*C at:
http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?6X358218
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Master Relay Mount |
>
>Bob,
>Anything new on this issue? Would you use them as delivered or would you
>recommend cutting the plastic off? Thanks. Don
Nope. Stancor hasn't answered any of several e-mails inquiring
about the change. This is at least one frustration I don't have
with folks who choose to put up with arcane and no-value-added
hoop jumping to sell to the certified world. Nobody is allowed
to make a change without telling us and most do not for fear
of being shot off the drawings. Hence, stuff that was certified
onto some 1960's airplane is still being manufactured in exactly
the same way today.
I haven't a clue as to why the booties were added. Until we
discover or are informed of a good reason for having them on,
it's your call. Personally, I'd probably remove them but since
they sell these things by the gazillions to other markets, I
have to acknowledge that they probably cause no harm either.
Bob . . .
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert
>L. Nuckolls, III
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: Master Relay Mount
>
>
>
>
>
> >
> >
> >In a message dated 11/23/2005 10:06:58 A.M. Central Standard Time,
> >rv-9a-online(at)telus.net writes:
> >
> >Bob, another issue with the booties is that they interfere with torquing
> >the mounting bolts. They will crack before the proper torque is
> >achieved. I've chucked my B&C contactors for this reason.
> >
> >Vern Little
> >RV-9A
> >
> >
> >Good Morning Vern,
> >
> >That brings up the question as to how we are determining "proper " torque?
> >
> >To have the attaching hardware stretched to just short of it's elastic
>limit
> >is one type of "torque". To squeeze a plastic such as the booties to a
> >point where no creeping or cracking is another form of "proper" torque.
>If
> >elastic stop nuts are used for attachment of the booted device, they
> >should hold
> >adequately at whatever point is determined to be optimum for the subject
> >fastening.
> >
> >The term "torque to specification" is often used without proper regard to
> >what it is that we are trying to accomplish.
>
> Exactly. When I design joints that have compressibility, I'll
> call out an all metal locknut. Drive the threaded fasteners together
> such that all the slack is out. Finally I'll specify some amount of
> additional rotation beyond the zero-slack point where thread pitch
> and rotation set the crush value.
>
> Stancor's choice of plastic in this instance is truly mystifying.
>
> Bob . . .
>
>
>--
>
>
>-- incoming mail is certified Virus Free.
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Do I Need an Ammeter? |
>
> > In reference to voltmeters, ammeters, and loadmeters, Bob says:
> > I'm not suggesting that one should not have these capabilities
> > on the panel. We're bringing a new line of high-quality loadmeters
> > and perhaps voltmeters to the market place in a few weeks.
>
> > I'll only suggest that these devices are adjuncts to active
> > notification of low voltage combined with a knowledge
> > of battery capacity as it relates to e-bus loads and the
> > builder's pre-selected endurance goals. Instrument readings
> > are interesting and useful in some venues but nearly useless
> > when operations/maintenance are not well planned and things
> > under the cowl are having a bad day.
>Agree wholeheartedly. Now, assuming I have a low voltage warning at, say
>13.0 volts, and an OV protection scheme with associated warning light, I
>want to
>know how and where is best to take voltage and amperage readings. Here's
>what
>I want to know about: I want to sense amperage load at the alternator B lead
>and the main battery and the standby battery. What is the appropriate
>indicator to use for each of those readings (i.e., a plus-minus ammeter or
>a positive
>indication ammeter (loadmeter?))? Do I need to also sample voltage at each
>of those locations or is the voltage the same throughout the electrical
>circuit?
>The way I understand it (from listening on this list) is that the voltage can
>be measured at any location in the entire circuit and that it is the same for
>the entire circuit. Amperage loads, however, will vary depending on where
>the reading is taken in the circuit. So, a reading at the alternator B lead
>could indicate when a new load is added to the circuit (such as pitot heat)
>whereas a reading at the main or standby battery will indicate the charge or
>discharge being applied to the respective battery. I would find such
>information to
>be, at the least, interesting.
> From what I understand, an acceptable method to sample the load at any one
>point in the circuit is by using a hall effect device. I understand a HE
>device
>can only provide me with an amperage reading - no voltage.
>If my understandings are convoluted, then please correct me. However, if
>I've understood it correctly, then please tell me how to best obtain the
>desired
>readings.
Correct. Hall effect devices sense the effects of current flowing
in the wire without actually taking energy out and wasting it. However,
the term 'acceptable' is not terribly relevant in the context of this
discussion. ALL methods are acceptable to someone's design goals.
You have correctly perceived and illuminated the astute system
designers task where goal is to mitigate the technician's tasks
when it comes to troubleshooting in the future. Our brothers in the
automotive world have done an excellent job with cars having implemented
techniques and technologies rooted in ideas over 30 years old. The
aviation side has not been so fortunate. Even if the system designer
had ideas and skills to put them into production, the present
environment for implementing new ideas stonewalls all but the most
'necessary' of new products.
We had some discussion about this on the List sometime back
where I wrote:
--------------------------------------------
Once you're on the ground, likelihood that ammeters and
voltmeters as-installed will reveal everything you need
to zero in on root cause of failure is remote . . . there
are not enough readings available from the rudimentary installations
of such displays.
(As an example: see alternator system troubleshooting guide
in notes of Appendix Z)
I've suggested that what ever electrical instrumentation
is installed on the panel, the number and kind of measurements
displayed will be far short of what's necessary to do a full-up
diagnostics evaluation of the electrical system.
I've further suggested that INDICATORS displaying present value
of any parameter are poor warning devices.
In the automotive world, one can plug diagnostic tools into
a handy connector and the vehicle spills its guts. Let's
consider how something similar might be implemented on an
OBAM aircraft.
Readers will recall many times that folks have posted calls
for assistance diagnosing an electrical system problem here
on the list. More often than not, remote assistance for
deducing the problem requires DATA . . . voltage and/or
current measurements at various points in the system give
clues for a divide-and-conquer approach to isolating the
problem.
The task ALWAYS involves putting your multi-meter probes
on various points, usually with the engine running. There
are few machines more difficult to troubleshoot than an
airplane.
What's a mother to do? Take a peek at:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdf/Electrical_System_Diagnostics.pdf
Here's an approach to adding a diagnostics connector to
the airplane during construction. In this case, I've
illustrated a couple dozen permanently installed test
leads brought out to a 37-pin D-sub connector. A jack
panel similar to the one shown on the last page can be
plugged into the test connector. One can sit in the right
(in flight if needs be) and make voltage measurements
in strategic spots to aid in isolating root cause of
the problem. With this type of system installed, I can
deduce root cause of about any misbehavior down to a
few connections, wires, and line-replaceable accessories.
The example shown only speaks to electrical system. One
might wish to extend test points in other systems out
to the same connector.
This illustrates my assertion that display of any small
number of electrical system parameters on the panel will
almost never be adequate for detailed diagnosis of a
problem. Further, if real time indicators are also poor
warning devices, then I'll suggest that carefully crafted,
active notification of failures will guide you to implementation
of alternative operating procedures. A few chunks of 22AWG
wire and a D-sub connector will permit detailed access to
the system under conditions better suited to diagnosis and
repair.
--------------------------------------------
Somewhere between what's installed on current production
aircraft and the full-up approach I suggested above lies
the answer to your question. The answers have little to
do with whether you use shunted ammeters or hall effect
devices, 10-digit research instruments or a $20 RadioShack
multimeter. The real considerations are where to I need
to peek at a voltage in order to better understand what
is NOT working?
Design goals for your decisions should consider (1) what
measurements am I most likely to have an interest in
in the future and (2) how much $time$ am I willing to
expend now to save perhaps more $time$ in the future?
I can't recall how many times I've stood two feet behind
a running prop to get an voltage reading under the cowl.
Not difficult but time consuming and less than pleasant.
What are you willing to do now so that you can make
these kinds of measurements from the relative comfort
of the copilot's seat . . . and perhaps even while
airborne?
One of the new products under development here is a
12-bit, 8-channel data acquisition system along with
a graphical user interface that will be compatible with
tapping data on just such a diagnostic connector. This
product would allow you to plug in, start recording,
go fly, duplicate symptom, land, and review the data
in the comfort of your shop. The same equipment might
be running in behind the seat on a long trip to capture
some intermittent but irritating failure event. These
are just the kinds of things I do at RAC right now.
I get paid big-bux to design, fabricate, install and
use operate measurement systems to fix problem
airplanes . . . remote sensing systems required to
mitigate design deficiencies long since removed from
cars.
My design goal is to offer tools for under $100 that
will let you do things on your airplane that an
auto mechanic can now do on your car.
Having said all that, I'll have to beg your indulgence
for not having offered some simplistic response like,
"Install this ammeter here, that voltmeter there and
keep a wet finger ready to hold up to the wind." The
real answers to your questions are not so simple and
they require some thought and learning on your part.
Now, if you really WANT a simple answer . . .
"Do whatever you've seen done on any other airplane
in the present or past and you'll be no worse off than
they are . . . but no better either. I'll add that
nothing I've seen done to date comes close to being
a real service in the task of troubleshooting the
airplane."
Any and all techniques currently illustrated in the
Z-figures fill the bill. Take your pick.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Too-close radio reception |
>
>Have recently been doing some close formation work- Transmissions from
>adjacent aircraft are often badly garbled as if the signal into the
>antenna is
>overloading the radio- same transmissions sound fine when quarter mile
>away. Any
>explanation and possible "fix"? Pehaps some way to reduce power of signal at
>coax connection on back of radio? Other plane always reports my
>transmissions
>as loud&clear. (Microair 760) Have tried changing relative position of
>plane to compensate for antenna location with no obvious affect.
>
>Mark Phillips - Columbia, TN
What you've discovered is the other end of the spectrum
for "dynamic range" of a radio receiver. At the lower end,
very small analog signals (on the order of 0.1 microvolt) begin to
to sink into atmospheric and circuit noise levels and no
amount of gain can lift them out of the mud. On the other hand,
digital signals can be perhaps two orders of magnitude weaker
because of modern digital processing that knows where to look
for the edge of a pulse and know that it was there in spite of
being surrounded by much larger signals of no interest. GPS
operates this way).
At the other end of the spectrum, large signals ultimately
overload circuits optimized to hear tiny signals and the
result is unintelligible audio.
The fix is to install install an 10db attenuator in the
coax to each airplane's transceiver for use during formation
flight. This amount of attenuation will generate a total of
20 db attenuation (10 on xmit, 10 on receive) for all flight
members while leaving you fair capability to talk to ground
stations (a 5 watt transmitter becomes a 0.5 watt transmitter
and a 0.4 microvolt receiver becomes a about a 1 microvolt
receiver.
Attenuators can be purchased (and must be rated in power for
as much or more than your transmitter power output. They
are not difficult to build either. I could do a comic book
on the project if there's enough interest.
Examples of commercial attenuators include:
http://www.e-meca.com/rf-attenuator.htm
http://www.surplussales.com/RF/RFAtten-2.html
Bob . . .
________________________________________________________________________________
| From: | "Ron" <rondefly(at)rtriano.com> |
| Subject: | Generator question |
Bob, If your suggesting me to consider the LV/OV indicator I assume the
generator is not a problem that needs to be shut off as with an alternator.
I have already built your two voltage controllers but with the generator I
guess I only need an indicator for either lo or high voltage.
Thankyou
Ron Triano
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Subject: Re: AeroElectric-List: Generator question
>
>If I am still using the Delco 20Amp generator on my 0200 continental do I
>really need the ANL60 with the brass strap? and for my ammeter should I get
>a 50MV 20amp shunt and do I really need the OV protect module for a
>generator? I am trying to get as close to the Z-19 drawings as I can with
>the two batteries.
Z-19 is an architeture drawing, not a wiring diagram guaranteed
to be suited to any particular task. Yes, sizes of components
and features offered by any particular accessory need to be
tailored to your design.
The output of a 20A machine offer risk during runaway if
you have a good battery. You might want to consider an
LV/OV indication such as that offered by B*C at:
http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?6X358218
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Do I Need an Ammeter? |
Mike,
An excellent summary. Thanks for sending your info.
Stan Sutterfield
In a message dated 12/03/05 2:58:01 AM Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
I found that with my basic running, I pull 13 amps on my all glass
panel. I also found that with everything on I can pull 47. So I set the
boundaries above and below that. I arrived at these values through my
initial flight testing. I can and do often look at the amps to confirm
that I suspect is the draw. I have found on occasion that when the
number shown, and the number in my head don't match, something is
amiss(usually I have failed to do something like turn the aux pump off
or whatever.) With a voltage number I would not get that. No matter what
I do, 14.1v is what I see. I have alarms for the voltage too. I run
14.1v +-.2 volts and set the alarms accordingly.
My summary is that my amps tells me much more than my volts. The number
often tells me that I have forgotten something. I suppose that this
would not work in a complex G-V. I also suspect that I am much more in
tuned with my current draw than most as I an all electric single engine
piston 2 seater and I know to the amp what the number should be no
matter What Im doing. Obviously both amps and voltage are important but
IF I had to prioritize, Id take amps over volts as an indication of
whats going on with my electrons.
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Van's ND alternator failure |
In a message dated 12/03/05 2:58:01 AM Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
While I've strongly suggested an idiot light for active
NOTIFICATION of low voltage, I'd much prefer automatic and
active RESPONSE to over voltage thus negating the value
of an ov warning light . . . if present in the system, it
would be illuminated for only milliseconds.
Bob,
Could an OV light be "locked" on until cleared to continue its indication
even though the OV condition has been mitigated. That way the pilot would have
active indication that required acknowledgement. Then the pilot would have
indications of both OV and LV.
Stan Sutterfield
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Too-close radio reception |
Robert L. Nuckolls, III wrote:
> snipped
>
> Attenuators can be purchased (and must be rated in power for
> as much or more than your transmitter power output. They
> are not difficult to build either. I could do a comic book
> on the project if there's enough interest.
>
> Examples of commercial attenuators include:
>
>http://www.e-meca.com/rf-attenuator.htm
>
>http://www.surplussales.com/RF/RFAtten-2.html
>
> Bob . . .
>
I'd be grateful. I've got the same problem & I'll bet it's a pretty
common problem.
The BNC models shown seem to be limited to around 2 watts. If that's
total transmitter power, they are inadequate for a panel mount radio.
Thanks,
Charlie
________________________________________________________________________________
| From: | "Tammy Goff" <tngoff(at)houston.rr.com> |
| Subject: | Re: Alternator with External Regulator? |
Bob, Thanks, I sort of came to that conclusion and will probably attempt to modify
one of the regulators mentioned on the list. I go the "how too" remove
the IR but was hoping one of the early GM alternators that are externally regulated
might have been found to fit in an RV. Thanks for the info. I am pretty
sure I can figure out how to remove the IR. George
________________________________________________________________________________
| From: | "David Carter" <dcarter11(at)sbcglobal.net> |
| Subject: | Re: Van's ND alternator failure |
If the OVM disconnected the alternator, then the Low Volt Light would be on
steady. Wouldn't that be enough active notification, even though coming
from a light labeled "Low Voltage or alternator off"?
David
----- Original Message -----
From: <Speedy11(at)aol.com>
Subject: AeroElectric-List: Re: Van's ND alternator failure
>
> In a message dated 12/03/05 2:58:01 AM Eastern Standard Time,
> aeroelectric-list-digest(at)matronics.com writes:
> While I've strongly suggested an idiot light for active
> NOTIFICATION of low voltage, I'd much prefer automatic and
> active RESPONSE to over voltage thus negating the value
> of an ov warning light . . . if present in the system, it
> would be illuminated for only milliseconds.
> Bob,
> Could an OV light be "locked" on until cleared to continue its indication
> even though the OV condition has been mitigated. That way the pilot would
> have
> active indication that required acknowledgement. Then the pilot would
> have
> indications of both OV and LV.
> Stan Sutterfield
>
>
>
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Alternator with External Regulator? |
"hoping one of the early GM alternators that are externally regulated
might have been found to fit in an RV"
You might find a GM alternator with external regulation that will fit, but since
all new alternators have internal regulators, you would be looking at late
60's, 70's (old). This was not Detroit's golden days for alternators. These old
designs have poor cooling and are not designed for high speed. They also have
a poor weight to output ratio. Modern alternator are much more efficient.
May I suggest you get a ND alternator and modify that. Over the last 20 years
alternators have made technological leaps from the early 80's, such as better
coil windings (more power per pound weight/smaller size), better cooling (dual
internal cooling fans) and designed for higher rotation RPM's. I would not
use an alternator design older than say late 80's.
There are other brands other than the NipponDenso, ND but from my research American
made alternators continue to have service problems on cars with more recalls,
service bulletins and service letters.
Even B&C uses the ND as the basis of there line of alternators. They take the
regulator out for you and it is only $410 to $685 bucks, plus a regulator ($228).
Removing the regulator in a ND alternator is not trivial, but it's not hard.
The internal regulation is on the low side (type-A VR) so you will need to modify
the brush holder by tapping into one brush lead and grounding the other lead.
Good luck. George
From: "Tammy Goff" <tngoff(at)houston.rr.com>
Subject: Re: Alternator with External Regulator?
Bob, Thanks, I sort of came to that conclusion and will probably attempt to modify
one of the regulators mentioned on the list. I go the "how too" remove
the IR but was hoping one of the early GM alternators that are externally regulated
might have been found to fit in an RV. Thanks for the info. I am pretty
sure I can figure out how to remove the IR. George
---------------------------------
Single? There's someone we'd like you to meet.
________________________________________________________________________________
| From: | "Rodney Dunham" <rdunhamtn(at)hotmail.com> |
| Subject: | RE: OVPM Active Notification |
The OV protection module, as designed by Bob and purchased from B&C, does
indeed provide active notification. It's not an "idiot light" but it's the
next best thing. The 5 amp pullable circuit breaker is black with the
numeral 5 imprinted in the center of the round pull tab. When the system is
in normal mode the black on black (my panel) sits quietly in my peripheral
vision. When the breaker trips, the white "collar" is easily visible and
catches my eye.
If we are exercising even minimal flight discipline and doing our routine
check lists periodically during flight, the non illuminated but easily
visible white breaker collar informs us that the thing has tripped. I
usually look next at the volt meter which is reading lower than when the ALT
is on line.
So far, the only time mine trips is during engine start. For this reason I
start my engine with the master in the middle, BAT only, position and add
the ALT after the engine lights off but before adding strobes, radios,
etc... I watch the Volt meter needle swing up to the usual indication and am
consoled. Not only is my OBAM aircraft's electrical system functioning
properly BUT I actually understand what it's doing and why!!! Thank you Bob
Nuckolls. My wife still wants to bake you a cake :o)
Rodney, Knoxville TN
Rotax 912UL with built-in 20 Amp PM alternator and Ducatti igniton and VR
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Alternator with External Regulator? (ND alternators |
with external regulation)
"B&C is the only company I'm aware of that offers
the ND alternator modified for external regulator
usage."
This company has both internal and external voltage regulated
ND alternators.
The internal ones are modified with an on-board OV crow bar module.
The other models are similar but the internal regulator is removed for
external regulation; these come as approved certified replacements
for certified factory planes.
George
http://plane-power.com/
---------------------------------
Single? There's someone we'd like you to meet.
________________________________________________________________________________
| From: | CardinalNSB(at)aol.com |
| Subject: | Avionics Common Grounding Question |
I am working on a Cessna aluminum can. I am ready to begin installation of
the avionics. Per the manufacturer's instructions (PSE), I have used
shielded wire for the intercom. The shield floats at the jack end, and the jacks
are insulated. At the intercom end, the shields are to be tied together.
Also, all the "lo" wires are tied together. Finally, the shields and the lo's
are tied together and inserted into the connector pin 1.
There is .3 ohm resistance between the incoming pin 1 (containing the
combined shields and lo's) and the outside of the case.
There is a separate connector Z for the airframe ground, there is .3 ohm
resistance between that pin and the outside of the case.
There is .2 ohm between pin 1 and Z.
Also, my nav com case is also grounded. Basically, since my cases are
grounded, how is the best way to physically handle the grounding?
I suppose it is possible to isolate the the case. Is that normally done?
Any tips?
Is it best to separate the airframe grounds from the other audio grounds
anyway?
I am considering adding a ground lug on the back of the audio panel for all
the shields and lo's and tying that to pin 1. And to take all the airframe
grounds to a common ground lug.
Or am I misunderstanding, and should just make one big common ground for
everything avionics. Or, any other advice, please.
Thank you, Skip Simpson
________________________________________________________________________________
| From: | "flyv35b" <flyv35b(at)ashcreekwireless.com> |
| Subject: | Re: Battery Bus Architecture |
> If you extend the bus away from the battery, it's not a battery bus
> any more . . . you'll want to add some form of min-battery contactor
> and the bus becomes #2, aux, #3, etc.
>
> A "battery bus" is right at the battery, is always hot and feeds light
> loads protected by no larger than 5A breaker or 7A fuses. If a feeder
> larger than 7A is needed, then you'd be well advised to add some form
> of remotely controlled disconnect for that feeder . . . right at the
> bus.
Bob, I just noticed your email from over a month ago and have wondered for
quite awhile why a feeder from the battery bus to a pull type breaker, for
instance, that feeds an E-BUS should be limited to 5A, as specified in FAR
23, or 7A as you mentioned above. What's wrong with using a 15A fuse at the
battery, supplying current to a 10A Klixxon breaker and then directly to an
E-BUS, as long as the wire is sized properly? It seems to me that this is
simpler and there is less chance of failure than adding a contactor as you
show in your schematic below.
I have never heard why the 5A limitation in the FAR is based on some logical
reason or was just an arbitrary value sufficient to supply most always hot
circuits.
Cliff A&P/IA
> One example of a high-current battery bus feeder is illustrated in
> http://www.aeroelectric.com/Pictures/Schematics/E-BusFatFeed.gif
> where we see how one can feed an overweight e-bus with a 15A feeder
> and a relay operated by the E-BUS ALTERNATE FEED switch.
________________________________________________________________________________
| From: | "Kellie Hand" <ckhand(at)earthlink.net> |
| Subject: | Lowrance Airmap 2000c connector plug |
I need to make (or buy) a cable that will let me use the data line for input
to my Trio EZ-Pilot wing leveler, but having trouble finding a part number
or source for the 6-pin plug on the back of the 2000c gps.
Anybody know the type or a source and part number for the 2000c's power/data
plug connector?
I'll ask Trio for help as well and post the answer when I find it, but if
you have an answer, please let me know!
Thanks,
Chris Hand
RV-6A, finishing kit stages
________________________________________________________________________________
| Subject: | Re: Lorance Air map 2000c connector plug |
| From: | James H Nelson <rv9jim(at)juno.com> |
Chris,
I had the same problem with Lorance. The end of the discussion
was to use their computer hook up from the GPS (with the 12 volt auto
power plug). I am using the Air map 500 and I have to pull out the #2
(signal) pin and the #5 (gnd). That way I can use it to drive my Digi
Trak... They are beginning to realize they need to put on their web site
how to use their GPS to drive something like an auto pilot.
Jim Nelson
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Battery Bus Architecture |
>
>
> > If you extend the bus away from the battery, it's not a battery bus
> > any more . . . you'll want to add some form of min-battery contactor
> > and the bus becomes #2, aux, #3, etc.
> >
> > A "battery bus" is right at the battery, is always hot and feeds light
> > loads protected by no larger than 5A breaker or 7A fuses. If a feeder
> > larger than 7A is needed, then you'd be well advised to add some form
> > of remotely controlled disconnect for that feeder . . . right at the
> > bus.
>
>Bob, I just noticed your email from over a month ago and have wondered for
>quite awhile why a feeder from the battery bus to a pull type breaker, for
>instance, that feeds an E-BUS should be limited to 5A, as specified in FAR
>23, or 7A as you mentioned above. What's wrong with using a 15A fuse at the
>battery, supplying current to a 10A Klixxon breaker and then directly to an
>E-BUS, as long as the wire is sized properly? It seems to me that this is
>simpler and there is less chance of failure than adding a contactor as you
>show in your schematic below.
The goal for turning switches on the panel to OFF is to minimize
the numbers and sizes for wires connected to the battery (the biggest
single power source in the airplane). Toward this goal, battery contactors
have always been positioned as close as practical to the battery itself.
>I have never heard why the 5A limitation in the FAR is based on some logical
>reason or was just an arbitrary value sufficient to supply most always hot
>circuits.
The 1960's certified singles with electric clocks and Hobbs meters
powered from an always-hot battery had a 'battery bus' of sorts.
Both of these circuits tied directly to the hot side of the battery
contactor through fuses of 5A or less. When I worked at Cessna in
'68, the "5A rule" was around and being fondly observed.
I don't believe I've seen the "5A rule" in the FARS. In fact, I don't
think I've seen it in print anywhere but I can ask around out at
RAC . . .
The notion behind the "5A rule" is to limit the energy that might
delivered from a faulted wire that's always tied to a battery.
Just between you and me a 5A breaker will drive a soft-fault
with MORE than enough energy needed to light off either gasoline
or kerosene. Now, a 5A fuse has an i(squared)-T constant a fraction
of that for a breaker. So, I've extrapolated that perhaps one could
go to a 7A fuse on an always hot feeder and still meet the spirit
and intent of the 5A rule.
Like most rules from bureaucratic organizations, the final
version is that which upsets the least number of people on
the committee. My personal airplane would have an e-bus
relay like that shown in . . .
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdf/Z32K.pdf
Now the size of the fuse with respect to crash safety is
a moot point. When all the switches are OFF, everything
is cold. I might have some always hot feeders for things like
cabin light . . . on a 1A fuse. Those are my design goals . . .
you can adjust yours as you see fit.
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Do I Need an Ammeter? |
Bob,
As usual, your answers are extremely frustrating! You talk all around the
subject but never address the subject headon.
" Correct. Hall effect devices sense the effects of current flowing
in the wire without actually taking energy out and wasting it. However,
the term 'acceptable' is not terribly relevant in the context of this
discussion. ALL methods are acceptable to someone's design goals."
Let's assume that my design goal is to sense current in the wire without out
taking energy out of the wire. Therefore, let's accept that sensing that
current using a HE device is "acceptable" to me.
" You have correctly perceived and illuminated the astute system
designers task where goal is to mitigate the technician's tasks
when it comes to troubleshooting in the future. Our brothers in the
automotive world have done an excellent job with cars having implemented
techniques and technologies rooted in ideas over 30 years old. The
aviation side has not been so fortunate. Even if the system designer
had ideas and skills to put them into production, the present
environment for implementing new ideas stonewalls all but the most
'necessary' of new products.
We had some discussion about this on the List sometime back
where I wrote:
--------------------------------------------
Once you're on the ground, likelihood that ammeters and
voltmeters as-installed will reveal everything you need
to zero in on root cause of failure is remote . . . there
are not enough readings available from the rudimentary installations
of such displays.
(As an example: see alternator system troubleshooting guide
in notes of Appendix Z)
I've suggested that what ever electrical instrumentation
is installed on the panel, the number and kind of measurements
displayed will be far short of what's necessary to do a full-up
diagnostics evaluation of the electrical system.
I've further suggested that INDICATORS displaying present value
of any parameter are poor warning devices.
In the automotive world, one can plug diagnostic tools into
a handy connector and the vehicle spills its guts. Let's
consider how something similar might be implemented on an
OBAM aircraft.
Readers will recall many times that folks have posted calls
for assistance diagnosing an electrical system problem here
on the list. More often than not, remote assistance for
deducing the problem requires DATA . . . voltage and/or
current measurements at various points in the system give
clues for a divide-and-conquer approach to isolating the
problem.
The task ALWAYS involves putting your multi-meter probes
on various points, usually with the engine running. There
are few machines more difficult to troubleshoot than an
airplane.
What's a mother to do? Take a peek at:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdf/Electrical_System_Diagn
ostics.pdf
Here's an approach to adding a diagnostics connector to
the airplane during construction. In this case, I've
illustrated a couple dozen permanently installed test
leads brought out to a 37-pin D-sub connector. A jack
panel similar to the one shown on the last page can be
plugged into the test connector. One can sit in the right
(in flight if needs be) and make voltage measurements
in strategic spots to aid in isolating root cause of
the problem. With this type of system installed, I can
deduce root cause of about any misbehavior down to a
few connections, wires, and line-replaceable accessories.
The example shown only speaks to electrical system. One
might wish to extend test points in other systems out
to the same connector.
This illustrates my assertion that display of any small
number of electrical system parameters on the panel will
almost never be adequate for detailed diagnosis of a
problem. Further, if real time indicators are also poor
warning devices, then I'll suggest that carefully crafted,
active notification of failures will guide you to implementation
of alternative operating procedures. A few chunks of 22AWG
wire and a D-sub connector will permit detailed access to
the system under conditions better suited to diagnosis and
repair.
--------------------------------------------
Somewhere between what's installed on current production
aircraft and the full-up approach I suggested above lies
the answer to your question. The answers have little to
do with whether you use shunted ammeters or hall effect
devices, 10-digit research instruments or a $20 RadioShack
multimeter. The real considerations are where to I need
to peek at a voltage in order to better understand what
is NOT working?"
Correct! Now let's assume that I want to peek at, say, a dozen locations in
the electrical system.
"Design goals for your decisions should consider (1) what
measurements am I most likely to have an interest in
in the future and (2) how much $time$ am I willing to
expend now to save perhaps more $time$ in the future?
I can't recall how many times I've stood two feet behind
a running prop to get an voltage reading under the cowl.
Not difficult but time consuming and less than pleasant.
What are you willing to do now so that you can make
these kinds of measurements from the relative comfort
of the copilot's seat . . . and perhaps even while
airborne?"
Now we're getting somewhere. Design goal is to have access to multiple
readings of the electrical system - whether airborne or on the ground. And I'm
willing to expend lots of $time$ now to provide said readings to save $time$ in
the future.
"One of the new products under development here is a
12-bit, 8-channel data acquisition system along with
a graphical user interface that will be compatible with
tapping data on just such a diagnostic connector. This
product would allow you to plug in, start recording,
go fly, duplicate symptom, land, and review the data
in the comfort of your shop. The same equipment might
be running in behind the seat on a long trip to capture
some intermittent but irritating failure event. These
are just the kinds of things I do at RAC right now.
I get paid big-bux to design, fabricate, install and
use operate measurement systems to fix problem
airplanes . . . remote sensing systems required to
mitigate design deficiencies long since removed from
cars.
My design goal is to offer tools for under $100 that
will let you do things on your airplane that an
auto mechanic can now do on your car."
But, your product is not yet available and I want to wire my airplane now.
Having said all that, I'll have to beg your indulgence
for not having offered some simplistic response like,
"Install this ammeter here, that voltmeter there and
keep a wet finger ready to hold up to the wind." The
real answers to your questions are not so simple and
they require some thought and learning on your part.
I have given it a lot of thought and I'm learning more every day.
Now, if you really WANT a simple answer . . .
"Do whatever you've seen done on any other airplane
in the present or past and you'll be no worse off than
they are . . . but no better either. I'll add that
nothing I've seen done to date comes close to being
a real service in the task of troubleshooting the
airplane."
Any and all techniques currently illustrated in the
Z-figures fill the bill. Take your pick.
Here's what I want. I want to know where the best locations are in an
aircraft circuit to peek at the electrons so as to be able to narrow down and
trouble shoot problems. There must be SOMEONE out there who can make suggestions
where to sample (peek at) volts and amps so as to be able to trouble shoot the
circuits. Disregard the constraints of money and time. If I want to install
twelve sensors throughout my electrical system so as to be able to check
readings and trouble shoot problems, where would you locate those sensors and what
type sensor(s) would you use?
I'm anxious to see what the run-around answer will be this time.
Actually, I've probably PO'd Bob enough that he won't answer.
Perhaps someone can help.
Again, my design goal:
---twelve sensors in electrical system (or make it 24 if that would be
better) (uh oh, better is a relative term like acceptable ... let's see ... just
make it 24 sensors)
---where to locate the sensors to permit troubleshooting
---type of sensors to get the readings
Anyone?
Stan Sutterfield
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator terminals |
>
>
> >
> >
> > >Thanks for the input, Bob.
> > >
> > >I note the comment: "If I were going to use this alternator in any
> > >application..." Which gets my antenna wiggling.
> > >
> > >General concerns about internally regulated alternators not withstanding,
> > >would you not recommend this alternator for a Z-19 based system?
> >
> > I have no basis to recommend it or discourage it. By "any application"
> > I
> > meant that if I needed to discover a way to make it work anywhere,
> > I'd proceed as follows . . .
> >
> > Bob . . .
> >
>
>
>On further study, I wonder whether this alternator can be used in a Z-19
>style of system. As I understand it, the "F" input is used to turn the
>alternator on & off -- thus if the Crowbar detects a failed regulator, the
>end result is that F shuts down & the alternator is taken offline.
>
>Based on your analysis of the internals of my existing alternator, it seems
>that there is no shutting it down short of making it stop spinning. Thus,
>there is no way to prevent it eating everything on the main and engine
>buses.
>
>The only solution I can see is to introduce (another!) contactor, and
>somehow use the output of the crowbar & regulator to turn the contactor
>on/off.
>
>Am I misreading the Z-19 diagram / alternator analysis?
Nope. You're exactly right. Until Revision 11 of the
Connection I had published a way to add positive control
and ov protection to the internally regulated alternator.
This was the oft mentioned Figure Z-24 (temporarily removed
from Appendix Z) where a b-lead contactor combined with ov
protection could be used satisfy those design goals.
See:
http://www.aeroelectric.com/temp/Z24_temp%20Model%20(1).pdf
As it turns out, there are risks to the alternator wired
this way IF the alternator is switched off under load.
Some builders have reported killing an alternator by operating
the switch from ON to OFF while the engine is running.
http://www.aeroelectric.com/articles/Alternator_Failures.pdf
There is risk to the S701-1 contactor if it's called upon
to disconnect a runaway alternator during a real ov event.
The rate of rise in alternator output may cause an arc to
form across the opening contacts and severely damage the
contactor.
Initially, I considered these risks minimal since there was
no need to operate the alternator control switch while the
alternator was loaded and if I sacrificed a contactor to
accomplish disconnection of the failed alternator from the
system, it was no big deal.
However. After at least two builders reporting killing
alternators and Vans and others began to recommend against
the technique, the drawing was withdrawn until modifications
could be made to at least mitigate if not eliminate the
risks.
There is a school of thought that offers certain brands
and part numbers of modern alternators as demonstrating
reliability sufficient to use as-is in airplanes. Reliability
(freedom from catastrophic failure) notwithstanding, the
modern alternator does not fit my personal design goals
for crafting a system with the same degree of hazard-free,
risk-free control enjoyed by pilots of production aircraft
since day-one. Further, as a writer for a broad spectrum
of owner/builder/operators, I'm reluctant to promote the
idea that one brand and part number of alternator should
be favored over the exclusion of all others. Especially
when virtually ANY automotive alternator's quirks
can be accommodated with minimal $time$, weight and
volume.
Preliminary tests have confirmed some ideas that will
offer ways to refine Z-24 such that the original goals
are met (1) absolute control at any time under any
conditions without risk to alternator or other
system components which then gives rise to (2) ability
to incorporate ov protection with any technology of
choice. These ideas will not be incorporated into
Z-24 for publication until they are tested and explained
in the work started a few weeks ago at
http://www.aeroelectric.com/articles/alternators/UA/Alternators_1.html
I've about got the next four pages of this article
completed.
In the mean time, if you wired your alternator with
the Z-24 temp version cited above and refrained from
switching the alternator ON/OFF while under load
with the engine running, you sidestep the risks cited
and will be ready to install the "final solution"
as soon as it's developed and published. I've already
discovered a way to make the el-cheeso S701-1 contactor
work.
Bob . . .
________________________________________________________________________________
| From: | "Dave Morris \"BigD\"" <BigD(at)DaveMorris.com> |
| Subject: | Re: Do I Need an Ammeter? |
He gave you a link for a schematic diagram that clearly showed a bunch of
sample test points that a person would probably want to use. I found it
within minutes of reading Bob's email.
Dave Morris
At 07:51 PM 12/4/2005, you wrote:
>
>Bob,
>As usual, your answers are extremely frustrating! You talk all around the
>subject but never address the subject headon.
> " Correct. Hall effect devices sense the effects of current flowing
> in the wire without actually taking energy out and wasting it. However,
> the term 'acceptable' is not terribly relevant in the context of this
> discussion. ALL methods are acceptable to someone's design goals."
>Let's assume that my design goal is to sense current in the wire without out
>taking energy out of the wire. Therefore, let's accept that sensing that
>current using a HE device is "acceptable" to me.
>
> " You have correctly perceived and illuminated the astute system
> designers task where goal is to mitigate the technician's tasks
> when it comes to troubleshooting in the future. Our brothers in the
> automotive world have done an excellent job with cars having implemented
> techniques and technologies rooted in ideas over 30 years old. The
> aviation side has not been so fortunate. Even if the system designer
> had ideas and skills to put them into production, the present
> environment for implementing new ideas stonewalls all but the most
> 'necessary' of new products.
>
> We had some discussion about this on the List sometime back
> where I wrote:
>
>--------------------------------------------
>
> Once you're on the ground, likelihood that ammeters and
> voltmeters as-installed will reveal everything you need
> to zero in on root cause of failure is remote . . . there
> are not enough readings available from the rudimentary installations
> of such displays.
>
> (As an example: see alternator system troubleshooting guide
> in notes of Appendix Z)
>
> I've suggested that what ever electrical instrumentation
> is installed on the panel, the number and kind of measurements
> displayed will be far short of what's necessary to do a full-up
> diagnostics evaluation of the electrical system.
>
> I've further suggested that INDICATORS displaying present value
> of any parameter are poor warning devices.
>
> In the automotive world, one can plug diagnostic tools into
> a handy connector and the vehicle spills its guts. Let's
> consider how something similar might be implemented on an
> OBAM aircraft.
>
> Readers will recall many times that folks have posted calls
> for assistance diagnosing an electrical system problem here
> on the list. More often than not, remote assistance for
> deducing the problem requires DATA . . . voltage and/or
> current measurements at various points in the system give
> clues for a divide-and-conquer approach to isolating the
> problem.
>
> The task ALWAYS involves putting your multi-meter probes
> on various points, usually with the engine running. There
> are few machines more difficult to troubleshoot than an
> airplane.
>
> What's a mother to do? Take a peek at:
>
>http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdf/Electrical_System_Diagn
>ostics.pdf
>
> Here's an approach to adding a diagnostics connector to
> the airplane during construction. In this case, I've
> illustrated a couple dozen permanently installed test
> leads brought out to a 37-pin D-sub connector. A jack
> panel similar to the one shown on the last page can be
> plugged into the test connector. One can sit in the right
> (in flight if needs be) and make voltage measurements
> in strategic spots to aid in isolating root cause of
> the problem. With this type of system installed, I can
> deduce root cause of about any misbehavior down to a
> few connections, wires, and line-replaceable accessories.
>
> The example shown only speaks to electrical system. One
> might wish to extend test points in other systems out
> to the same connector.
>
> This illustrates my assertion that display of any small
> number of electrical system parameters on the panel will
> almost never be adequate for detailed diagnosis of a
> problem. Further, if real time indicators are also poor
> warning devices, then I'll suggest that carefully crafted,
> active notification of failures will guide you to implementation
> of alternative operating procedures. A few chunks of 22AWG
> wire and a D-sub connector will permit detailed access to
> the system under conditions better suited to diagnosis and
> repair.
>--------------------------------------------
>
> Somewhere between what's installed on current production
> aircraft and the full-up approach I suggested above lies
> the answer to your question. The answers have little to
> do with whether you use shunted ammeters or hall effect
> devices, 10-digit research instruments or a $20 RadioShack
> multimeter. The real considerations are where to I need
> to peek at a voltage in order to better understand what
> is NOT working?"
>
>Correct! Now let's assume that I want to peek at, say, a dozen locations in
>the electrical system.
>
> "Design goals for your decisions should consider (1) what
> measurements am I most likely to have an interest in
> in the future and (2) how much $time$ am I willing to
> expend now to save perhaps more $time$ in the future?
>
> I can't recall how many times I've stood two feet behind
> a running prop to get an voltage reading under the cowl.
> Not difficult but time consuming and less than pleasant.
> What are you willing to do now so that you can make
> these kinds of measurements from the relative comfort
> of the copilot's seat . . . and perhaps even while
> airborne?"
>
>Now we're getting somewhere. Design goal is to have access to multiple
>readings of the electrical system - whether airborne or on the
>ground. And I'm
>willing to expend lots of $time$ now to provide said readings to save
>$time$ in
>the future.
>
> "One of the new products under development here is a
> 12-bit, 8-channel data acquisition system along with
> a graphical user interface that will be compatible with
> tapping data on just such a diagnostic connector. This
> product would allow you to plug in, start recording,
> go fly, duplicate symptom, land, and review the data
> in the comfort of your shop. The same equipment might
> be running in behind the seat on a long trip to capture
> some intermittent but irritating failure event. These
> are just the kinds of things I do at RAC right now.
> I get paid big-bux to design, fabricate, install and
> use operate measurement systems to fix problem
> airplanes . . . remote sensing systems required to
> mitigate design deficiencies long since removed from
> cars.
>
> My design goal is to offer tools for under $100 that
> will let you do things on your airplane that an
> auto mechanic can now do on your car."
>But, your product is not yet available and I want to wire my airplane now.
>
>
> Having said all that, I'll have to beg your indulgence
> for not having offered some simplistic response like,
> "Install this ammeter here, that voltmeter there and
> keep a wet finger ready to hold up to the wind." The
> real answers to your questions are not so simple and
> they require some thought and learning on your part.
>I have given it a lot of thought and I'm learning more every day.
>
> Now, if you really WANT a simple answer . . .
>
> "Do whatever you've seen done on any other airplane
> in the present or past and you'll be no worse off than
> they are . . . but no better either. I'll add that
> nothing I've seen done to date comes close to being
> a real service in the task of troubleshooting the
> airplane."
>
> Any and all techniques currently illustrated in the
> Z-figures fill the bill. Take your pick.
>Here's what I want. I want to know where the best locations are in an
November 27, 2005 - December 04, 2005
AeroElectric-Archive.digest.vol-fa