Today's Message Index:
----------------------
1. 03:43 AM - LOM OVP System (Wolfgang Trinks)
2. 07:20 AM - Re: Z-13 and Dual Electronic Ignitions (Robert L. Nuckolls, III)
3. 08:47 AM - Re: Alt Field Trip (Rhett Westerman)
4. 11:33 AM - Source for Pins & Extraction tools (Paul McAllister)
5. 01:29 PM - WX900 Stormscope (DHPHKH@aol.com)
6. 02:08 PM - Re: Source for Pins & Extraction tools (Robert L. Nuckolls, III)
7. 04:40 PM - Re: Source for Pins & Extraction tools (Don Honabach)
8. 05:43 PM - (Gary Casey)
9. 05:57 PM - Re: Re: Whelen strobe current draw (Shannon Knoepflein)
10. 06:08 PM - Re: Z-13 and Dual Electronic Ignitions (Shannon Knoepflein)
11. 06:10 PM - Re: Avionics bus (Shannon Knoepflein)
12. 06:57 PM - Supporting the other ends of our gyros (Ralph E. Capen)
13. 08:00 PM - Re: Avionics bus (Jim Pack)
14. 08:25 PM - Re: Z-13 and Dual Electronic Ignitions (Don Honabach)
15. 08:36 PM - Re: Avionics bus (John Slade)
16. 08:39 PM - Re: Source for Pins & Extraction tools (Robert L. Nuckolls, III)
17. 08:59 PM - Re: Supporting the other ends of our gyros (Robert L. Nuckolls, III)
18. 09:10 PM - Re: Avionics bus (Robert L. Nuckolls, III)
19. 09:21 PM - Re: Source for Pins & Extraction tools (Don Honabach)
Message 1
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--> AeroElectric-List message posted by: "Wolfgang Trinks" <Wolfgang.Trinks@flugbereitschaft.com>
Hello Bob,
I am a professional pilot flying a Citation II in Karlsruhe-Baden/Germany(
with an engineering background) a former canadian F-18 Airbase. At the time
I am conducting restoration of a Stampe SV4 Biplane(all wood) for my private
use. Fourtunately we have our own JAR 145 maintenance facility, so I have
good support for dealing with the feds( its a certified aircraft in
Germany).
For the engine I am in progress of a STC for the LOM engine because I think
there is no future in the old Renault.
As I have to put an electric system into the plane and I have never done
this before from scratch your experiance written down will be a lot of help.
I am now starting the planing of the system and one of my first
considerations is the OVP-System given the 28Volt Magnetron Generator
supplied to the engine. ( I am aware that B&C has introduced a alternator
system for the engine, but unfortunately its not certified in Germany).
One fact that is growing of more and more importance during my project is to
be very carefull putting up more and more weight to an airplane that was
very basic in the first place. Also the space on my firewall is very
limited.
So looking at your drawing Z-18 raises a question of what I wood be
interested in your opinion:
Would it be ok related to the failure scenarios of a mechanical regulator to
only use the GENERATOR FIELD DISCONNECT RELAY to cut the field in an
OVP-event and to rely on the reverse current cuttoff relay consisted in the
regulator to disconnect the D+ line from the B+ line due to the resulting
breakdown of the generator output?
Do you have experience with this LUN regulator?
I have studied the little scematic in the cap and came to the opinion that
it is a 3 point type (cutout, voltage and current) where 2 contacts( cutout
and current) are located on one coil core.
I have to admit that I do not fully understand the functionality of the PR
pin. It seems to me to be a potential paralleling in/output for a
2-Generator system.
Nevertheless I have meassured that it is normally open and if the cutout
relay is connecting the generator voltage shows up there after passing a
coil on the voltage relay.
If one knew the effects on the voltage regulation( so to avoid influance
there) it would be a positive possible indication for generator operation
because it shows the state of the cutout relay.
Best Regards
Wolfgang Trinks, StampeSV4C,D-EBHR, EDSB
Message 2
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| Subject: | Re: Z-13 and Dual Electronic Ignitions |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:44 PM 5/10/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "David Carter"
><dcarter@datarecall.net>
>
>Mark Navratis (czechsix?),
>
>I am the least qualified to even attempt a comment here, but that never
>stops me from trying.
>
>I, too, am in process of modifying Z-13 for my all electric Mazda rotary
>engine.
Why Figure Z-13 if you have only one alternator drive?
> I, too, am concerned about a battery failure, and equally concerned
>about battery contactor failure. (I don't have a great fear of the
>probability of either, but believe there is enough anecdotal history to make
>me design my system so either or both will be a "no sweat" situation (Bob's
>"prime directive").
Which is why we consider the option of adding a second battery . . .
>That is why I'm going to use a Permanent Magnet Alternator (John Deere 35,
>55 or 85 amp) (the "alternate alternator is labeled "Dynamo" in Z-13 - this
>is a PM alternator).
> - PM alternators/dynamos operate with no need for a battery - ever.
> -- So, if battery fails, PM Alternator continues to put out
>regulated DC to the left hand (in Z-13) terminal of the battery contactor,
>which is where the wire that feeds the Battery Bus connects, which means
>that the battery can short, open, or melt and all run out a hole in the
>bottom of the plane -- and the battery bus, essential bus, and all electric
>engine will hum away on alternator power.
Not necessarily so. Some regulators (including the B&C regulator
for the SD-8/200G series alternators) won't allow the alternator
to come on line without a battery. I'm not certain of the rational
for this design but I would guess that it's a recognition of the
single phase, pm alternator's really ratty output. There are some
more modern, 3-phase designs available now. I have no personal
experience with them. But don't go on faith that because the
alternator has no need of field excitation that it will automatically
be available and useable sans battery. This takes some degree
of testing and/or research on the alternator/regulator's characteristics
as a system.
>I'm going to run only a single alternator - the PM alternator. They are
>supposed to be so reliable, and totally independent of the battery, that I
>don't see why I'd want all the "risks" that come with a "battery dependent,
>and battery contactor dependent std alternator.
If you have only one alternator drive, then I'd stay with the modern
fielded alternator . . . especially an ND. In over 10 years
of supplying this alternator to the OBAM community, B&C
has yet to have a gross failure of an alternator
due to wearout. All failures to date were installer/
operator induced. There has been a sprinkling of regulator
failures for a variety of reasons . . . there's probably
a similar risk of failure for a pm regulator . . . perhaps
even more risk. PM regulators have to be designed to CARRY
load currents. The parts are more highly stressed and need
heat sinks. A regulator for wound field alternators carries
only field current . . . 3A max, less than 1A in cruising
flight. MUCH less stress.
>I'm adding a second battery, so will have a "2 battery, single PM
>alternator" system.
So what you might consider is Z-11 with a Z-30 second
battery. This is the system I proposed in the aux battery
management module article in SA some years ago. A pair
of identical batteries with the yearly swap around of
new->main and main->aux combined with the demonstrated
reliability of an ND alternator is pretty hard to beat for cost
effectiveness and efficiency (the ND will give you more snort
with smaller installed volume and weight).
> - Haven't decided if I want to use 2 regular size batteries (may need
>that for "battery-only electrical endurace" close to equal to "fuel
>endurance"): 1) IF my electrically fed and fired engine current draw is
>not too great (don't have all the current draw info yet for 2 ignition
>coils, efi pump (1 on at a time except for T.O. & land), and Tracy Crook's
>EC-2 ignition-injection controller (engine computer), THEN may go with a
>small expensive light weight battery isolated just for the engine.
Which gives you dissimilar batteries to monitor and maintain
with no convenience of calendar based swap-around. Are you
planning to periodically capacity check your batteries?
> 2) If need the extra juice, and if need the extra
>amp capacity for cranking engine, will go the easy, heavier, cheaper way and
>go with 2 17AH batteries (this is what I feel will be my choice - makes
>annual battery replacement and rotation simple, lower cost, better
>reliability, and I don't care about the difference in weight - my Mazda
>rotary already saves me about 20#.)
Hear, hear . . .
> > Bob,
> >
> > I'm a bit baffled on your reply that "if you have two engine driven power
> > sources, then you don't need two batteries". A couple months ago we had
> > a lively exchange where you were poo-pooing my questions about tying
> > electronic ignition leads directly to the battery to eliminate failure
> > points between the battery and the battery bus (something about swatting
> > gnats). Then when you realized I was talking about DUAL electronic
> > ignition, you said that I should have dual batteries. My plan up until
> > then had been to go with Z-13, single battery/dual alternator. But this
> > does mean that the single battery is a single point failure that will
> > result in engine failure if it's integrity is destroyed. Someone
> > recently had a case where their battery lead bolt broke clean off (wasn't
> > it a Powersonic RG battery?).
Yeah . . . probably got my tongue tangled around my eye-teeth
and couldn't see what I was saying. If you have an electrically
dependent airplane, adding a second battery is the most effective
first-step to improved reliability.
In retrospect, I'm wondering if I was thinking about the engines
that run a single ignition or fuel delivery system wherein there
are lots of single points of failure. In these cases, our comfort
factor can go up only by improving the reliability of the single
system with judicious parts selection, operating at reduced stress and
more tightly controlled attention to details of assembly. In
these airplanes, I'm wondering if two batteries adds that much
overall system reliability . . .
The 4-pound, SD-8 installation is a very attractive alternative
to a second battery . . and depending on how you use your airplane,
may be an acceptable step-down from dual-battery reliability in
trade for unlimited endurance with a lot less weight and lower
cost of ownership.
We launch into detailed fault tree and reliability analysis
tasks when these kinds of discussions come up on the certified
iron. Problem is that MTBF numbers used for most hardware
are derived analytically. By the time you get a few dozen
assumptions piled on top of each other in a very complex
system, the overall analysis is pretty suspect. The FAA
realizes this so they put a 10x factor on requirements.
One failure per million flight hours is their idea of
failure proof. I personally don't have much confidence in
these exercises and don't believe they give the customer
good value. It's better to design for failure tolerance
in confidence than to design for failure proof with
fondest wishes.
> >
> > Anyway, I still don't know what to think....I've gotta believe that
> > complete battery failure with an RG is rare, but nevertheless I thought
> > maybe it would be better to go with dual batteries. The configuration
> > I've tentatively settled on is the one Klaus Savier recommends....single
> > alternator and single main battery, plus a very small standby battery
> > that is charged through a Schottky diode to isolate it from everything
> > else, and runs one of the ignition systems. This seemed to me to be the
> > lightest, simplest and cheapest setup that offered assurance of ignition
> > system redundancy. It doesn't have the convenience of running an SD-8 if
> > the main alternator quits, but since I'm running a B&C main alternator I
> > felt the odds of being stuck somewhere (albeit safely on the ground) away
> > from home with my alternator dead to be pretty low risk and probably
> > worth the compromise in the long run.
It stands to reason that lightly stressed parts are going to
be more reliable operating up to and including the limits
of capacity than highly stressed parts. This is why we design
wing and prop attach hardware with lots of headroom. Alternators
and batteries are routinely operated at the limits of their capability
(and from experience we know that the do fail and wear out -
an airplane may see dozens of batteries and several alternators
over its lifetime of operation on one set of wings).
This is why we adopt the philosophy of designing for failure
tolerance in electrical systems (you gotta install
a ballistic parachute to design for failure tolerance in wings).
> >
> > I was just amused at your statement on Z-13 because I thought that you
> > did not advocate this setup for dual electronic ignition?
Correct. Sometimes after a day of brain-wrestling with
these things all day at RAC, my thought train gets
derailed . . .
One of these days, it would interesting to do a formal fault tree
and reliability analysis of the various system options for publication
but that takes a lot of time and data (another reason
certified ships cost so much). Soooo . . . in the mean time,
I'll have to rely on you guys to throw down the flag when you
detect a derail . . .
Bob . . .
Message 3
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--> AeroElectric-List message posted by: "Rhett Westerman" <Rhettwesterman@cox.net>
Rick,
Not sure if you have an OVM in there or not. I had the same trouble and a
new OVM fixed it.
best,
Rhett
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Rick
Caldwell
Subject: AeroElectric-List: Alt Field Trip
--> AeroElectric-List message posted by: "Rick Caldwell"
<racaldwell@hotmail.com>
Hello All,
Anyone have experience in alternator circuit failures that could narrow down
my search?
I have a 40A B&C alternator with the LR3B-14v for control. My 5A field CB
pops. However, after a minute or so, I can reset it and it stays in, most
of the time. I have the Aeroelectric loadmeter and the load on resetting is
high but settles down to the normal 10% load after a minute or so. Adding
or cutting off loads does not seem to influence the tripping. No blown
fuses on any of the other circuits. I just installed a new Concorde 25RG-XC
battery thinking that was the problem. It wasn't. Tripped on take-off last
night. I will now start looking for intermittent shorts tomorrow. I sure
don't want to find that the LR3B is bad. I've flown 3.5 yrs with no alt.
problems until now.
Rick Caldwell
RV-6
Message 4
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| Subject: | Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Paul McAllister" <paul.mcallister@qia.net>
Hi all,
I am approaching the stage where I will be wiring up my UPS GX60 Nav/Com & SL 70
transponder. The units come supplied with 37 pin D style connectors and I am
seeking some advice.
Where can I purchase a suitable crimping tool, insertion/extraction tool and some
pins & sockets. I would be interested to know what size wire do people typically
use in these pins to ensure a good crimp
Thanks, Paul
http://europa363.versadev.com/
Message 5
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| Subject: | WX900 Stormscope |
--> AeroElectric-List message posted by: DHPHKH@aol.com
Gang,
Anybody have a pinout and/or installation manual for a WX-900
Stormscope?
Dan Horton
Message 6
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| Subject: | Re: Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 01:33 PM 5/11/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Paul McAllister"
><paul.mcallister@qia.net>
>
>Hi all,
>
>I am approaching the stage where I will be wiring up my UPS GX60 Nav/Com &
>SL 70 transponder. The units come supplied with 37 pin D style connectors
>and I am seeking some advice.
>
>Where can I purchase a suitable crimping tool, insertion/extraction tool
>and some pins & sockets.
See:
http://www.aeroelectric.com/Catalog/tools/tools.html#rct-3
http://www.aeroelectric.com/Catalog/tools/tools.html#dse-1
http://www.aeroelectric.com/Catalog/connect/connect.html#S604
http://www.aeroelectric.com/Catalog/BCcatalog.html
> I would be interested to know what size wire do people typically use in
> these pins to ensure a good crimp
24-20 AWG wire works well in these pins. 20AWG for
power/ground and 22AWG for everything else is
good . . .
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 7
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| Subject: | Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Don Honabach" <don@pcperfect.com>
Hi Everyone,
I noticed that when crimping the machined pins for the D style
connectors that the insulation on the wire usually ends up exposing
about a 1mm of wire despite my best attempts to keep the insulation
right next to the pin during the crimp.
Obviously 1mm of wire showing isn't going to be a problem, but it bugs
me. Is this normal for these type of pins/connectors? Has anyone been
able to keep a 0 tolerance on the wire shown at the back end of the pin?
I'm just trying to get a feeling of whether I need to practice and just
come up with a better technique, or if I'm fighting a losing battle.
Thanks!
Don Honabach
Tempe, AZ - Zodiac 601HDS
P.S. Getting ready to start my electrical installation and can't wait.
A little burned out on the mark, drill, de-bur, corrision protect, and
rivet it game.
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:bob.nuckolls@cox.net]
Subject: Re: AeroElectric-List: Source for Pins & Extraction tools
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <bob.nuckolls@cox.net>
At 01:33 PM 5/11/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Paul McAllister"
><paul.mcallister@qia.net>
>
>Hi all,
>
>I am approaching the stage where I will be wiring up my UPS GX60
>Nav/Com &
>SL 70 transponder. The units come supplied with 37 pin D style
connectors
>and I am seeking some advice.
>
>Where can I purchase a suitable crimping tool, insertion/extraction
>tool
>and some pins & sockets.
See:
http://www.aeroelectric.com/Catalog/tools/tools.html#rct-3
http://www.aeroelectric.com/Catalog/tools/tools.html#dse-1
http://www.aeroelectric.com/Catalog/connect/connect.html#S604
http://www.aeroelectric.com/Catalog/BCcatalog.html
> I would be interested to know what size wire do people typically use
> in
> these pins to ensure a good crimp
24-20 AWG wire works well in these pins. 20AWG for
power/ground and 22AWG for everything else is
good . . .
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
direct advertising on the Matronics Forums.
Message 8
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--> AeroElectric-List message posted by: "Gary Casey" <glcasey@adelphia.net>
<>
This is probably heresy, but I use a simple ohmmeter. It has to be a fairly
good one to detect the difference between the resistance of the coil (less
than 1 ohm) and the shorted points. I ONLY connect the ohmmeter when I am
right the correct timing value and then bump the crank very slowly. Do it
with any speed and there will occur a voltage spike when the points open
that could damage the ohmmeter. The easy way is to back the crank up and
turn it forward, listening for the impulse coupling click at about TDC.
Then back the crank up to just before 25 BTC and very slowly go forward. A
little time consuming, but if you only do it once in a great while it works.
Just don't send me a bill for your blown-up ohmmeter.
Gary Casey
Message 9
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| Subject: | Re: Whelen strobe current draw |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
Actually, he's right on the money. Its 42J total, released in 4
flashes, I think its like 18, 8, 8, 8, released within like 405ms, with
the first 26 within 200ms. I did a detailed analysis of this a few
weeks ago, if I didn't bore you to death, go back and find it and it
should answer any and all questions.
The end result is 20 gauge is plenty for power and ground, and 22-3
shielded will suffice for runs to the strobes of 15 feet.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
Irvine
Subject: AeroElectric-List: Re: Whelen strobe current draw
--> AeroElectric-List message posted by: Bill Irvine
<wgirvine@yahoo.com>
> So, if we assume that the strobe outlets produce a
> flash once every 860 milliseconds, then Outlets 3 42
> watt/seconds divided by .86 seconds is 48 watts, or
> 4 amps in a 12 volt system. This 4 amp "event" is
> alternating with Outlet 1. Therefore, the power
> pack is drawing 4 amps continuously, am I right?
I'm no expert on this, but keep in mind that for the
CF (Comet Flash) power supplies, everytime they
"flash", they actually produce four flashes in very
rapid succession. If the sum total of the four
flashes is 42 joules, then your calculations might be
correct. But if each one of the four flashes is 42
joules, then you will be off by a factor of four.
Bill
Lancaster, CA
C-310 (still in pieces)
do not archive
__________________________________
http://search.yahoo.com
Message 10
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| Subject: | Z-13 and Dual Electronic Ignitions |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
Bob,
As I have mentioned before, there is ONE case where an avionics master
is really needed. It's to protect the Chelton EFIS computer during its
boot-up stage when its opening and closing config files. If it reboots
while it has one of these files open, corruption of this file is a
possibility, rendering the unit useless.
Now, I won't go as far to say that this behavior is acceptable and
correct, but the fact is it does exist (whereas ALL of the other calls
for an avionics master are baseless, as you say).
I think this area is one that might need to be addressed in the future
as more things go electronic and computerized. Hopefully, the
manufacturers will make them immune to this, but, if not, it will need
to be addressed by a Z drawing.
My solution and suggestion to a solution is to create an avionics buss
that also doubles as an essential (or endurance) buss, that is fed by an
alternate feed switch. I also suggest this architecture to people that
are uncomfortable sleeping at night without their avionics behind a
master, whether it's for unfounded passed on blurb, or if its just for
convenience. This architecture adds one switch (av master) to a typical
Z14 with ess buss, and really provides the best of both worlds.
Shannon
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: Re: AeroElectric-List: Z-13 and Dual Electronic Ignitions
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> >
>Bob,
>The main incentive I had for going down this path was finding a simpler
>method of incorporating the dreaded avionics bus into your essential
>bus architecture. I know this is a major point of contention for you,
>but I find myself dealing with the reality of a manufacturers
>recommendation to provide protection for certain components, and I'm
>too far into the stream to change horses. More important to me than
>the failure modes was finding a way to simplify by combining the
>avionics bus and the essential bus by isolating the main and essential
>busses during starting. The aux bus backup was a lower priority
>consideration to allow me to have some of these sensitive instruments
>powered up during start without exposure to the brownout situation you
>have discussed, and secondarily to provide a second power source for my
>electronic flight instruments. I know this kind of talk probably makes
>you crazy, but in my never ending quest to expose my ignorance of
>electronics, I was compelled to present it to you.
> I would appreciate your consideration of this idea.
A little disappointed perhaps but not crazy. And the goal
here is not to please me or any body else on the list.
I've often suggested that folks are better off with a system
they understand and are comfortable with than to be worrying
about something unique to their level of understanding.
Keep in mind that the vast majority of SE aircraft flying today
are wired not unlike the CessnaBeechPiperMooneys of decades
gone by . . . including OBAM aircraft. Airplanes wired
per the Z-drawings are rare in comparison with the total
fleet of aircraft.
When I ask people to justify their wish to modify any
of the systems we've published, it's not because I have
any notion of convincing them to "do it my way." My
query is aimed at acquiring insight as to some point
of engineering I may have overlooked. The Z-drawings
have evolved a lot over the last 10 years and I'd be
foolish to believe they should not evolve further.
My job is not to persuade you to do anything. My
job is to help you understand how the system works.
Your job is to craft a system that is not distracting
because of concerns or misunderstood operation. So
in answer to your questions:
You can certainly add a switch in series with normal
feedpath diode to service as an "avionics master"
You don't need to use a contactor for an aux battery
unless the battery is robust enough to aid in cranking
and/or it is your intent NOT to use it to assist the main
battery in cranking. Indeed, when the automatic aux
battery management concept was published in Sport Aviation
about 6 years ago, the aux battery was perhaps a 4-6 a.h.
device connect to the bus via a 30A power relay like our
S704-1.
May I suggest the following actions which may work
toward mitigating your concerns? Give me a list of
folks who have supplied you with equipment that they
claim is "sensitive" . . and let's at least ask them
to provide a justification for their assertions
based on physics.
I presume you followed the conversation
with Electronics International over the last two weeks.
It turns out that they haven't a clue as to why their
products should or should not be "protected".
While they claimed credit for full compliance under
TSO requirements that include DO-160 testing, they
didn't truly understand the significance of the tests
they paid money to accomplish. Nor did they understand
the significance of that testing with respect to their
customer's reasonable expectations.
In EVERY case I've looked at over the past 15 years,
not one company asking for an "avionics master switch"
was able to enlighten me with an explanation. In more than
half the cases, they admitted that there was no
justification and that the topic of avionics master
switch was part of the boiler-plate used to craft installation
manuals since the 60's and nobody has ever bothered to
review that requirement and take it out of the book.
I don't know if the outcome of such an exercise would influence
the way you configure your airplane and it doesn't matter.
Bottom line is that what ever goes into YOUR airplane
should minimize your worries as an owner and maintainer
of the airplane so that you can maximize your performance
as the pilot of that airplane.
Bob . . .
Message 11
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--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
It is actually possible that Greg's system needs protected, just like my
Chelton, due to it opening and closing files during bootup. I think
Greg's is more PC based so it might be better at handling this, but the
Chelton isn't as forgiving.
These computers are really the ONLY thing that even has a chance of
needing the AV Master, as Bob has shown many times.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Terry
Watson
Subject: AeroElectric-List: Avionics bus
--> AeroElectric-List message posted by: "Terry Watson"
<terry@tcwatson.com>
Bob,
Have you had any progress (or tried) convincing Greg Richter at Blue
Mountain Avionics that their EFIS-1 doesn't need to be on an avionics
bus?
Terry
RV-8A
Blue Mountain EFIS-1
Message 12
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| Subject: | Supporting the other ends of our gyros |
--> AeroElectric-List message posted by: "Ralph E. Capen" <recapen@earthlink.net>
Fellow listers,
What are you doing (have you done) to support the forward (back) ends of your long
gyros?
A couple of mine will go through the next forward bulkhead so I can probably rivet
on a piece of angle and clamp the gyro to that. One (AI) is too short but
is right on top of another (HSI) that goes through the next forward bulkhead
- I was thinking of making up a spacer to put those two together and clamp them
together using the support on the one that goes all the way through to hold
both. Another of mine (S-Tec30 TC/AP) is also too short and is not close enough
to another one to "lean" on.
Your thoughts please,
Message 13
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| Subject: | Re: Avionics bus |
--> AeroElectric-List message posted by: "Jim Pack" <jpack@igs3.com>
In reality, it doesn't need a general AV master, it simply needs a dedicated
switch to that piece of avionics - only because one was not built into the
unit itself.
- Jim
----- Original Message -----
From: "Shannon Knoepflein" <kycshann@kyol.net>
Subject: RE: AeroElectric-List: Avionics bus
> --> AeroElectric-List message posted by: "Shannon Knoepflein"
<kycshann@kyol.net>
>
> It is actually possible that Greg's system needs protected, just like my
> Chelton, due to it opening and closing files during bootup. I think
> Greg's is more PC based so it might be better at handling this, but the
> Chelton isn't as forgiving.
>
> These computers are really the ONLY thing that even has a chance of
> needing the AV Master, as Bob has shown many times.
>
Message 14
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| Subject: | Z-13 and Dual Electronic Ignitions |
--> AeroElectric-List message posted by: "Don Honabach" <don@pcperfect.com>
>> As I have mentioned before, there is ONE case where an avionics
master is really needed. It's to protect the Chelton EFIS computer
during its boot-up stage when its opening and closing config files. If
it reboots while it has one of these files open, corruption of this file
is a possibility, rendering the unit useless.
If you wanted to keep a clean panel with one less switch, wouldn't it
possible to put a capacitor at the power input leads to act as a small
battery/noise filter for the device to take care of the temporary sags
in voltage during startup?
>> Now, I won't go as far to say that this behavior is acceptable and
correct, but the fact is it does exist (whereas ALL of the other calls
for an avionics master are baseless, as you say).
For such a nice unit, I'm surprised it doesn't have a better startup
design.
Regards,
Don
-----Original Message-----
From: Shannon Knoepflein [mailto:kycshann@kyol.net]
Subject: RE: AeroElectric-List: Z-13 and Dual Electronic Ignitions
--> AeroElectric-List message posted by: "Shannon Knoepflein"
--> <kycshann@kyol.net>
Bob,
As I have mentioned before, there is ONE case where an avionics master
is really needed. It's to protect the Chelton EFIS computer during its
boot-up stage when its opening and closing config files. If it reboots
while it has one of these files open, corruption of this file is a
possibility, rendering the unit useless.
Now, I won't go as far to say that this behavior is acceptable and
correct, but the fact is it does exist (whereas ALL of the other calls
for an avionics master are baseless, as you say).
I think this area is one that might need to be addressed in the future
as more things go electronic and computerized. Hopefully, the
manufacturers will make them immune to this, but, if not, it will need
to be addressed by a Z drawing.
My solution and suggestion to a solution is to create an avionics buss
that also doubles as an essential (or endurance) buss, that is fed by an
alternate feed switch. I also suggest this architecture to people that
are uncomfortable sleeping at night without their avionics behind a
master, whether it's for unfounded passed on blurb, or if its just for
convenience. This architecture adds one switch (av master) to a typical
Z14 with ess buss, and really provides the best of both worlds.
Shannon
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: Re: AeroElectric-List: Z-13 and Dual Electronic Ignitions
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> >
>Bob,
>The main incentive I had for going down this path was finding a simpler
>method of incorporating the dreaded avionics bus into your essential
>bus architecture. I know this is a major point of contention for you,
>but I find myself dealing with the reality of a manufacturers
>recommendation to provide protection for certain components, and I'm
>too far into the stream to change horses. More important to me than
>the failure modes was finding a way to simplify by combining the
>avionics bus and the essential bus by isolating the main and essential
>busses during starting. The aux bus backup was a lower priority
>consideration to allow me to have some of these sensitive instruments
>powered up during start without exposure to the brownout situation you
>have discussed, and secondarily to provide a second power source for my
>electronic flight instruments. I know this kind of talk probably makes
>you crazy, but in my never ending quest to expose my ignorance of
>electronics, I was compelled to present it to you.
> I would appreciate your consideration of this idea.
A little disappointed perhaps but not crazy. And the goal
here is not to please me or any body else on the list.
I've often suggested that folks are better off with a system
they understand and are comfortable with than to be worrying
about something unique to their level of understanding.
Keep in mind that the vast majority of SE aircraft flying today
are wired not unlike the CessnaBeechPiperMooneys of decades
gone by . . . including OBAM aircraft. Airplanes wired
per the Z-drawings are rare in comparison with the total
fleet of aircraft.
When I ask people to justify their wish to modify any
of the systems we've published, it's not because I have
any notion of convincing them to "do it my way." My
query is aimed at acquiring insight as to some point
of engineering I may have overlooked. The Z-drawings
have evolved a lot over the last 10 years and I'd be
foolish to believe they should not evolve further.
My job is not to persuade you to do anything. My
job is to help you understand how the system works.
Your job is to craft a system that is not distracting
because of concerns or misunderstood operation. So
in answer to your questions:
You can certainly add a switch in series with normal
feedpath diode to service as an "avionics master"
You don't need to use a contactor for an aux battery
unless the battery is robust enough to aid in cranking
and/or it is your intent NOT to use it to assist the main
battery in cranking. Indeed, when the automatic aux
battery management concept was published in Sport Aviation
about 6 years ago, the aux battery was perhaps a 4-6 a.h.
device connect to the bus via a 30A power relay like our
S704-1.
May I suggest the following actions which may work
toward mitigating your concerns? Give me a list of
folks who have supplied you with equipment that they
claim is "sensitive" . . and let's at least ask them
to provide a justification for their assertions
based on physics.
I presume you followed the conversation
with Electronics International over the last two weeks.
It turns out that they haven't a clue as to why their
products should or should not be "protected".
While they claimed credit for full compliance under
TSO requirements that include DO-160 testing, they
didn't truly understand the significance of the tests
they paid money to accomplish. Nor did they understand
the significance of that testing with respect to their
customer's reasonable expectations.
In EVERY case I've looked at over the past 15 years,
not one company asking for an "avionics master switch"
was able to enlighten me with an explanation. In more than
half the cases, they admitted that there was no
justification and that the topic of avionics master
switch was part of the boiler-plate used to craft installation
manuals since the 60's and nobody has ever bothered to
review that requirement and take it out of the book.
I don't know if the outcome of such an exercise would influence
the way you configure your airplane and it doesn't matter.
Bottom line is that what ever goes into YOUR airplane
should minimize your worries as an owner and maintainer
of the airplane so that you can maximize your performance
as the pilot of that airplane.
Bob . . .
direct advertising on the Matronics Forums.
Message 15
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--> AeroElectric-List message posted by: "John Slade" <sladerj@bellsouth.net>
> It is actually possible that Greg's system needs protected, just like my
> Chelton, due to it opening and closing files during bootup.
I don't understand this. I thought all the EFIS/ONE data was either rom
based or on a CD/DVD. Either way I don't see how you can corrupt a file
unless you're running off writable media. Am I wrong?
John Slade
Message 16
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| Subject: | Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 04:40 PM 5/11/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: "Don Honabach" <don@pcperfect.com>
>
>Hi Everyone,
>
>I noticed that when crimping the machined pins for the D style
>connectors that the insulation on the wire usually ends up exposing
>about a 1mm of wire despite my best attempts to keep the insulation
>right next to the pin during the crimp.
>Obviously 1mm of wire showing isn't going to be a problem, but it bugs
>me. Is this normal for these type of pins/connectors? Has anyone been
>able to keep a 0 tolerance on the wire shown at the back end of the pin?
Better to have strands exposed this amount than to have the
insulation pushed against the pin . . . the goal is to have
strands go all the way to the bottom of the crimp cup. If
Insulation rides against the pin, there is a question as to
sufficient strip length. When the pin is inserted into the
connector shell, this small gap is down inside the rear
molding of the connector and not visible.
Bob . . .
Message 17
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| Subject: | Re: Supporting the other ends of our gyros |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:59 PM 5/11/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Ralph E. Capen"
><recapen@earthlink.net>
>
>Fellow listers,
>
>What are you doing (have you done) to support the forward (back) ends of
>your long gyros?
>
>A couple of mine will go through the next forward bulkhead so I can
>probably rivet on a piece of angle and clamp the gyro to that. One (AI)
>is too short but is right on top of another (HSI) that goes through the
>next forward bulkhead - I was thinking of making up a spacer to put those
>two together and clamp them together using the support on the one that
>goes all the way through to hold both. Another of mine (S-Tec30 TC/AP) is
>also too short and is not close enough to another one to "lean" on.
>
>Your thoughts please,
Does the manufacturer suggest support at both ends?
Be careful that you don't make things worse than you
think they are already. Most instruments are designed
to be mounted from the face. I you were to add "support"
to a long instrument with brackets to some forward
structure, you may find that you're really adding support
to the panel via the case on the instrument. I can see
this causing failure of the instrument mounting provisions
due to overload.
Unless what you propose is recommended by the manufacturer,
proceed with caution.
Bob . . .
Message 18
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--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:08 PM 5/11/2003 -0400, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>It is actually possible that Greg's system needs protected, just like my
>Chelton, due to it opening and closing files during bootup. I think
>Greg's is more PC based so it might be better at handling this, but the
>Chelton isn't as forgiving.
>
>These computers are really the ONLY thing that even has a chance of
>needing the AV Master, as Bob has shown many times.
Is this an "Avonics Master" or a simple switch that accommodates
some unique requirement of the system? Last time I talked
to Greg, he said that there was no hazard to his system
due to brownout . . . it would just have to reboot thus
taking longer to get ready to go to work. So big deal . . .
If the Chelton system has any chance of going brain-dead
due to brownout, how would one propose to deal with a situation
like hard fault on a pitot heat line that opens the
fuse (or worse yet) breaker by putting a momentary load
of 300A or more on the system? There are OTHER causes of
reduced system voltage than engine cranking and they
might happen in flight (That's why we use fuses and
breakers).
I'm not sure I'd have much confidence in a system that
couldn't get stood back up after an unexpected brownout of
any duration, rise and fall times and amplitude. This
might be more of a reason for the ever popular Band-Aid
battery diode fed from the bus. Momentary brownouts of
any character are washed out by the battery.
There's no excuse for not being able to handle this
kind of event but if the manufacturer is insistent,
then a small diode fed support battery is the 100%
solution.
Bob . . .
Message 19
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| Subject: | Source for Pins & Extraction tools |
--> AeroElectric-List message posted by: "Don Honabach" <don@pcperfect.com>
Bob,
>> When the pin is inserted into the connector shell, this small gap is
down inside the rear molding of the connector and not visible.
Thanks - I really appreciate you taking the time to give full answers.
Seems like a lot of folks that give advice either don't know the whys or
won't take the time to explain.
Any way, I'll have to look for different connector shells. My current
one for my UPS GPS/COMM rids the pin right to the back end so any
exposed wire is visible which started my concern (just doesn't have that
clean look and I'd rather think that the insulation was helping to
support the wire). I'll try some different brands of shells and if the
installation sits inside the connector shell I'll be a happy camper.
Thanks!
Don
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:bob.nuckolls@cox.net]
Subject: RE: AeroElectric-List: Source for Pins & Extraction tools
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <bob.nuckolls@cox.net>
At 04:40 PM 5/11/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: "Don Honabach"
>--> <don@pcperfect.com>
>
>Hi Everyone,
>
>I noticed that when crimping the machined pins for the D style
>connectors that the insulation on the wire usually ends up exposing
>about a 1mm of wire despite my best attempts to keep the insulation
>right next to the pin during the crimp.
>Obviously 1mm of wire showing isn't going to be a problem, but it bugs
>me. Is this normal for these type of pins/connectors? Has anyone been
>able to keep a 0 tolerance on the wire shown at the back end of the
>pin?
Better to have strands exposed this amount than to have the
insulation pushed against the pin . . . the goal is to have
strands go all the way to the bottom of the crimp cup. If
Insulation rides against the pin, there is a question as to
sufficient strip length. When the pin is inserted into the
connector shell, this small gap is down inside the rear
molding of the connector and not visible.
Bob . . .
direct advertising on the Matronics Forums.
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