AeroElectric-Archive.digest.vol-jj
February 25, 2010 - March 15, 2010
A(continued): IF you have a problem, however - having the option to
do so is nice. Suppose you had a OV condition that trips the
alternator offline and you are IMC or VFR-on-top and your battery is
draining pretty bad before you can get down - I'll take a possible OV
condition in that scenario over dead screens, and reengage the
alternator field. If the battery is low already it will absorb a good
deal of the excess current, dropping the voltage and protecting the
avionics to a degree. As the charge state of the battery comes up the
OV will trip out the alt field again when the voltage rises beyond
the set point of the crow bar, but you've gained some battery charge
in the process. Lather, rinse, repeat, and fly the airplane. You may
fry the regulator (which was suspect already by default of your
situation) and you won't do the battery any favors with the high
current charge/discharge cycles - but you'll keep your avionics up
and give yourself a chance to get down safely.
Bob: This reader demonstrates no appreciation for
failure tolerant design or understanding of what
constitutes a hazardous voltage condition for
the rest of the system.
The root rationale for resetting CB on the
alternator field includes . . .
(1) there are occasionally situations where an ov
protection system of ANY style by ANY manufacturer
can be induced to nuisance trip. The ability
to do a cautious/attentive reset is useful.
(2) legacy operating philosophy CB trips that
shut down especially useful equipment, resetting a
breaker is is allowed one time. In a failed-regulator
scenario, resetting the breaker once simply produces
a second trip. In no case does it put extraordinary
stresses on other components that are still working.
A (reader): Bob talks in absolutes. When there is over lap or
preference, it gets a little confusing. Remember some of Bob's ideas
are more in the preference area than technically necessary.
The main reason for the ALT CB is when using a "crow-bar" or B & C
regulator, which has a crow bar in it. The CB is an integral part of
the "crow-bar system", an over voltage protection device as you know.
The crow bar works by dead shorting the CB and tripping it. The Plane
power alternator that I recommend, also uses or needs a CB. You could
still use a fuse from any CB, however, a CB makes more sense, if you
plan on occasionally tripping circuit "normally". (read on)
Here is my interpretation of Bob's CB/Fuse philosophy.
Since the OV "crow bar" might trip "accidentally", the ability to
reset it, is desirable; the CB is obviously more desirable than a
fuse for something you expect to normally trip on occasion. Bob
denies the crow-bar is finicky or subject to nuisance trips. OK? If
its true, it never tripped unless, than you could use a fuse, right?
Well the crow-bar is not that stable. There are other ways to protect
from OV, and this is one that Bob likes, and it needs a CB to work.
Bob: NEVER have I suggested that the OV crowbar devices
manufactured by me, B&C, Plane-Power or OV disconnect
devices by Perhelion, Electro-Delta, or BF Goodrich
ARE or ARE NOT "finicky".
Anyone who understands legacy OV protection philosophies
will offer due diligence in designing and qualifying
their device for intended purpose in accordance with
DO-160/Mil-STD-704 design goals.
ALL diligent designs are subject to nuisance tripping
from transients for reasons that have nothing to do
with design of the OV protection device.
Even the most diligent designs are subject to errors
in understanding ALL the potential nuisance trip
sources in the targeted airframes. Since the LR-1
first flew on Voyager's closed circuit tests of the
coast of CA up to the present LR-3 configuration
there have been THREE changes to design to address
new discoveries AFTER the product was fielded.
The first such condition was noted before Voyager did
the around the world flight where LR-2 regulators
were installed. The last two changes were prompted
by discoveries that were not brought to light until
thousands of regulators had been giving satisfactory
service for years. My current production OV modules
have benefited from lessons-learned in the last
two modifications. Further, those lessons learned
would have been the same whether the ov module opened
a circuit breaker or operated a relay.
A(contintued):In general his "logic" or philosophy on "fused" items,
is you can live with out them or should if it blows, with proper
design of your system. In most production planes (read all) only CB's
are used or resettable thermal current limiting devices. Bob is
right, fuse are cheap, simple, light and work to protect the wires as
good as any CB. The down side is you have to carry extra fuses and
it's difficult to fix or re-set in flight.
However the latter issue, resetting in flight, is moot in Bob's
opinion. He proposes you don't want to replace a fuse, ever, until
you land. Obviously if a CB pops, you might consider not resetting
it, like if you smell something. At least you let a CB cool and only
allow one reset. So bottom line, if a fuse blows it's OK to leave it
blown till you land since you don't need the device and it might harm
something to reset that circuit, in the scenario in his mind.
Bob: this writer chooses to ignore my suggestion
that fuses are PREFERABLE for equivalent protection
ONLY when the builder understands and strives for failure
tolerant design. This design philosophy produces a
system were fuse replacement is NOT NECESSARY because
the airplane has no device 'critical for continued flight'.
i.e. every devise with a potential for critical
operation has a PLAN-B. Hence, whether the fuse is
nuisance tripped or the device simply dies, no immediate
hazard to flight is created.
If one chooses to design and operation his/her OBAM
aircraft in the spirit and intent of a C-172, then
by all means, use breakers throughout. You may indeed
wish to do a one-time reset on several of the airplane's
electro-whizzies. When I fly, it's ALWAYS a rented
TC aircraft, it's ALWAYS fitted with breakers and
I ALWAYS have this failure-tolerance-package in the
flight bag . . .
http://aeroelectric.com/Pictures/Misc/Failure_Tolerance.pdf
A(continued) IMHO, for heavy current items like gear retraction
motors, CB's are generally preferred. A electric motor can have a
transient overload and be fine. So CB reset is hand.
Bob: Fuses are NOT suitable for hi-inrush loads or
the protection of fat-wire feeders and they've never
been recommended for that application. In these instances
fuse-like CURRENT LIMITERS and or fusible links are
suggested in my writing (TC aircraft use current
limiters too). The reader demonstrates no appreciation for
legacy design goals and recipes for success that go
back nearly 100 years.
A(continued): The Alternator is a little different? You could use a
fuse. Bob makes grand statements of philosophy or "Bob rules", but
than it "appears" he contradicts himself or changes the philosophy to
fit his current opinion. That is not a criticism, we all move the
goal post sometimes. However if you think you can live with out your
alternator, say fly on battery power, than the fuse on the ALT is not
critical. You could sub in a fuse for simplicity and less
cost/weight. If you have a stock internal voltage regulated
alterantor the CB on the "IGN" lead is even less useful. The current
is like 0.10 amps or less.
If you are using an internally regulated alterantor than the fuse can
be say 0.5 or 1 amp since the "IGN" lead is only a 'signal' to wake
up or sleep the alternator, not a "field wire" or power to the
voltage regulator. All the power goes through the b-lead. If you are
using a Plane Power, than use a 5 amp (or what ever size) CB they
suggest, since that is also a "crow bar" type CB popper as well. As
you might know a crow-bar dead shorts the CB to trip it, removing
power to the regulator, which removers power to the the alternator
"Field", which de-energizes the alternator, if its miss behaving.
Bottom line. Bob's way is not the only way or best way, just his way
which is totally fine. Some times its over kill. Some times the
reasons he gives are opposed to other opinions (but there is always a
justification). It's just not that important, and if you follow his
philosophy you will be ok, albeit may be on the overkill side. The
only thing I really think is wrong is putting a crow bar & over
voltage relay on the b-lead of a internally regulated alternator.
That is heavy and a Jury Rig. It also will damage the alternator in
the event of a nuisance trip.
Bob: discussed, researched, and demonstrated not to be true.
See recent updates to chapter on alternators.
A(continued): If you are worried about your internally regulated
alterantor (and you will be if you believe everything Bob says, which
he does not have proof of) than get a Plane Power unit. Also good is
B&C alterantor with an external regulator, but I would get a Transpo
V1200 regulator not a B&C voltage regulator. The Transpo V1200 uses
solid state OV protection and not a CB tripper crow bar. It also cost
1/3rd or 1/4th the cost of B&C voltage regulator price.
Bob: The really cool thing about the Internet is that
it's ALL out there for reading. The really bad thing
about the Internet is that it's ALL out there for the
reading.
Individuals who make due-diligence searches of the
archives for guidance must be wary of advice that carries
just enough truth to give the appearance of knowledgeable,
well considered, recipes for success.
But like the exchange detailed above, Some writers
place their otherwise good advice in question
when they carry tar bushes in one hand and buckets
of tomatoes in the other. The writing is also
suspect when the reasoning demonstrates no understanding
of the physics or simple ideas that go into recipes for
success that have rich histories of performing to design
goals.
Bob . . .
________________________________________________________________________________
| Subject: | Re: GPU for Piper |
| From: | John McMahon <blackoaks(at)gmail.com> |
Thanks Bob. That was also my decision when powering the systems., primarily
for having the battery on line but seeing all those other 'smart' TC folks
do it the other way was confusing me. I'm doing it your way!
On Thu, Feb 25, 2010 at 6:42 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
> At 11:30 PM 2/24/2010, you wrote:
>
>> Bob, Could you expand on the two philosophies or point me to a further
>> discussion. I've been wrestling with both ways and each time I decide one
>> way, I think about it some more and change my mind...again? Is either
>> choice superior or is it six of one and half a dozen of the other?
>>
>
> If you hook ground power to the battery side of the
> GP_Contactor, you can charge the battery without
> powering up the aircraft. Further, you would not
> be able to hook ground power to the aircraft WITHOUT
> having the battery on line as well. This would be
> my preferred configuration.
>
> Production TC do it both ways but predominantly
> the OTHER way. I'm mystified as to the rationale
> for doing it the other way . . . somebody made
> that decision long before my time and isn't around
> to explain it any more. I'm unable to deduce
> any advantage that would give it precedence over
> the first way. I am presuming that they had a
> "good" reason but I don't know what it is.
>
> Bob . . .
>
>
--
John McMahon
Lancair Super ES, S/N 170, N9637M (Reserved)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: RFC: My external power schematic |
At 10:21 AM 2/22/2010, you wrote:
>
>
>nuckolls.bob(at)aeroelect wrote:
> >
> > Let's discuss the ways in which the schematic in
> > Z-31A falls short of your design goals.
> >
>
>
>First, the minor differences:
>
>I put an LED across the solenoid so that I have some immediate
>feedback that it is engaged when I think it should be (and not
>engaged when I think it shouldn't be).
This is what's suggested in Figure 3 of
http://aeroelectric.com/articles/grndpwr.pdf
The press to test fixture shows when the contactor
is energized and also proves availability of ground
power if the press-to-test works.
>I also added a second diode reversed across the solenoid, similar to
>the one you have across the main battery contactor in Z-31A. Is
>there something different about the external power contactor that
>makes this safety not recommended?
Why would you want to close the ground power contactor
from a battery that's okay? As another reader pointed
out, this negates the protection for reversed polarity
in the ground power source.
>The major departure in my schematic is the addition of the
>switch. The center position gives the same behavior as
>Z-31A. The "force" position I put in there as a means of
>overcoming the problem I saw with the Otter.
I can't figure out how the schematic cited above
doesn't address this.
>With any luck, I'd just leave the switch on Auto for the lifetime of
>the airplane. But weird stuff happens... :)
Why not replace the switch breaker with a pullable
breaker in Figure 3 and probably leave that
breaker OUT for the lifetime of the airplane?
Bob . . .
________________________________________________________________________________
| From: | Peter Pengilly <peter(at)sportingaero.com> |
| Subject: | Re: GPU for Piper |
Bob,
When I was in the military we sometimes had aircraft in the hangar on
ground power for many hours at a time as electrics or avionics snags
were investigated. Ground Power plugs were wired up to by-pass the
battery, and most times (always?) the battery connector was pulled.
Also, if the battery (24v Ni-Cad) was flat we took it down to the
battery bay and got another. We also used to start the aircraft every
time on external power (unless a power rig wasn't available).
Perhaps this thinking has found its way by osmosis into the small
aircraft TC community without any good reason? Perhaps its also an
attempt to stop owners charging old wet electrolyte batteries in situ,
with the risk of acid spillage, or worse?
Regards, Peter
Robert L. Nuckolls, III wrote:
>
>
> At 11:30 PM 2/24/2010, you wrote:
>> Bob, Could you expand on the two philosophies or point me to a
>> further discussion. I've been wrestling with both ways and each time
>> I decide one way, I think about it some more and change my
>> mind...again? Is either choice superior or is it six of one and half
>> a dozen of the other?
>
> If you hook ground power to the battery side of the
> GP_Contactor, you can charge the battery without
> powering up the aircraft. Further, you would not
> be able to hook ground power to the aircraft WITHOUT
> having the battery on line as well. This would be
> my preferred configuration.
>
> Production TC do it both ways but predominantly
> the OTHER way. I'm mystified as to the rationale
> for doing it the other way . . . somebody made
> that decision long before my time and isn't around
> to explain it any more. I'm unable to deduce
> any advantage that would give it precedence over
> the first way. I am presuming that they had a
> "good" reason but I don't know what it is.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | David Nelson <david.nelson(at)pobox.com> |
Hi Bob,
Looking at Z-11/M, why is the endurance bus protected by a fuse from the
battery bus but not the main bus? Is it just for the sake of the switch or
something else?
Thank you,
/\/elson
________________________________________________________________________________
| Subject: | Re: Official color of levers |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Ron,
I looked into this years ago and there is no lack of information. Just Google "Cockpit
Ergonomics" and have a go at it. There are FAA and ICAO regulations on
the shapes of landing gear and flap knobs, but color is not the issue for controls.
What color is the blue knob in red night-lighting??
Being R-G color-blind, I carry a piece of paper from the FAA saying IO can see
color. So that makes me an expert.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288285#288285
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Circuit protection - Amps |
I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp PTC.
I replaced those by new LED nav lights, which draw about 0.5A, and should
need a protection device not bigger than 1A.
If I leave the circuit with the same 7A protection, what are the
implications?
Carlos
________________________________________________________________________________
| From: | Bill Mauledriver Watson <MauleDriver(at)nc.rr.com> |
| Subject: | OT & Cross Post - reflections on the transition from |
analog to digital navigation equipment and failure modes
Way off topic: Here's a video of an almost-accident by NZ60 landing at
Apia (Samoa?). It depicts how the failure of an ILS component at the
airport went undetected by multiple RF-based analog pieces of Nav
equipment including the ILS receivers, the FMS (digital?), and the
autopilot systems Only after the 3 pilots broke out and couldn't make
sense of the lights did their doubts finally result in a go-around
followed by a safe landing. Fascinating and informative for any
instrument pilot:
http://www.youtube.com/watch?v=GelRBhJ4gmI&feature=PlayList&p=C325C5DA287EC296&index=7
It's 3 parts long - if you enjoy it, you'll find part 2 and 3.
Anyway, this had me reflecting on how much more capable and reliable
digital based navigation (GPS) might be compared to analog based
systems. In the above example, everything in the aircraft worked as
designed. Procedures were for the most part, followed and executed.
The automated navigation systems of the aircraft were prepared to fly it
into the ground. The collective brain of the 3 pilots (NZ designation)
was the only thing that saved a crash. Is a WAAS based overlay of the
approach susceptible to a similiar sort of failure?
Arguably, one can now see the point in time where fully automated
flights, without pilots, can be accomplished. And of course these
flights are being made by mililtary drones and the Mars explorers.
No new news here, just marveling at it all.
I posted the response below to Sonex293 on the Aeroelectric list - check
the mikrokopter link at the bottom if you haven't seen it before.
That's what got me day dreaming in the first place....
--------
The next gen of OBAM aircraft? It reminds me that we are probably in
the golden age of OBAMA and personal GA (no pun intended).
Just reverse this scenario
http://alturl.com/gmqu
As unmanned and unpiloted aircraft hit their stride, those unpredictable
piloted aircraft with their free thinking, and at times, malevolent
pilots are going to be increasingly pushed into airspace restricted to
non-commercial, non-military, no-ATC-services areas. Probably to be
called 'uncontrolled' airspace... and we know how rare that has become.
Makes one savor the ability to hand fly our hand built aircraft from
coast to coast, all within the system.
Neat link. Thanks.
sonex293 wrote:
Kits are available...
http://www.mikrokopter.de/
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: Circuit protection - Amps |
The fuse is supposed to protect the wire. Shouldn't be an issue. You can downsize
the fuse based on expected draw and any unexpected draw will pop the fuse.
I had similar Whelens which I replaced with LED units...kept the same fuse as I
am carrying one of the old units (with both lenses) as a backup in case of hangar
rash at a destination....I can easily swap out to my backup and the wiring
is already set-up.
My .02
Ralph
-----Original Message-----
>From: Carlos Trigo <trigo(at)mail.telepac.pt>
>Sent: Feb 26, 2010 10:01 AM
>To: aeroelectric-list(at)matronics.com
>Subject: AeroElectric-List: Circuit protection - Amps
>
>I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp PTC.
>
>I replaced those by new LED nav lights, which draw about 0.5A, and should
>need a protection device not bigger than 1A.
>
>
>
>If I leave the circuit with the same 7A protection, what are the
>implications?
>
>
>
>Carlos
>
________________________________________________________________________________
| Subject: | Re: Clearing some away some fog and fuzzy logic . . |
.
| From: | "user9253" <fran4sew(at)banyanol.com> |
The main issue in this debate seems to be whether to use fuses or circuit breakers.
Like many decisions in life, there is more than one way to accomplish a
goal. One way may have certain advantages over the other way, and visa-versa.
Many times the decision boils down to a matter of personal preference; and I
believe that is the case here. I have replaced hundreds of fuses during my career
as an industrial electrician, but only a few circuit breakers. Fuses can
blow from a variety of reasons like old age, operating near maximum rating for
long time, heat from a bad fuse-holder connection, and of course overload or
short circuit. And circuit breakers will trip for most of those same reasons.
The blade type fuses used in modern cars are much less likely to develop a
high resistance connection with the fuse holder as compared to the old cylinder
shaped fuses. Some people might argue that fuses will blow quicker than circuit
breakers will trip, thus offering better protection. Although technically
true, I do not think the time difference is significant. One way to avoid
nuisance blowing of fuses is to use a larger size. For instance, an avionics
manufacturer might recommend using a 1 amp fuse. If you use a 3 amp fuse instead,
there will be a lot less chance of it blowing. The fuse should be sized
to protect the wire, not the load. If the equipment manufacturer is depending
on you to protect their device from internal failure, then choose another brand.
I am going to use fuses (where applicable) in my plane because they are lighter,
cost less, take up less room, and are easily replaceable. My fuses will have
indicator lights that will illuminate when the fuse blows. Van's Aircraft
is using fuses in the RV-12 and it meets the ASTM standards. If you want to
use circuit breakers, that is OK with me. To each his own.
Quote from technician,
> "The only thing I really think is wrong is putting a crow bar & over voltage
relay on the b-lead of an internally regulated alternator. That is heavy and a
Jury Rig. It also will damage the alternator in the event of a nuisance trip."
End Quote.
Quote from Bob,
> "discussed, researched, and demonstrated not to be true."
End Quote
I am taking Bob's side here. The technician is basing his statement on rumors.
Bob has done experiments with expensive lab equipment. I trust his work. Even
if the technician is correct (which I doubt), I would rather ruin an alternator
than have an over-voltage condition ruin thousands of dollars worth of avionics.
Although the technician is highly critical of Bob's recommendations, I do not
take his statements as being a personal attack. Still, he was expressing his
opinions as fact and pooh-poohing Bob's, which is not a nice thing to do. If
I say something that others disagree with, it is OK to tell me, as long as it
is done diplomatically. LOL
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288307#288307
________________________________________________________________________________
| From: | "Glaeser, Dennis" <dennis.glaeser(at)hp.com> |
| Subject: | Re: Circuit protection - Amps |
From: Carlos Trigo (trigo(at)mail.telepac.pt)
Date: Fri Feb 26 - 7:16 AM
I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp PTC.
I replaced those by new LED nav lights, which draw about 0.5A, and should
need a protection device not bigger than 1A.
If I leave the circuit with the same 7A protection, what are the
implications?
Carlos
--------------------------------------------------------
Did you replace the wires? If not, then virtually no implications.
If you put in smaller wires, then you need to use a smaller protection device.
Protection is for the wires - so they can't overheat in case of a short.
Dennis
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Re: Circuit protection - Amps |
Thanks Dennis
Just keep answering my questions in all forums (fora) in which we both lurk
. :-)
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Glaeser, Dennis
> Sent: sexta-feira, 26 de Fevereiro de 2010 16:54
> To: AeroElectric-List(at)matronics.com
> Subject: AeroElectric-List: Re: Circuit protection - Amps
>
>
>
> From: Carlos Trigo (trigo(at)mail.telepac.pt)
> Date: Fri Feb 26 - 7:16 AM
>
> I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp PTC.
>
> I replaced those by new LED nav lights, which draw about 0.5A, and should
> need a protection device not bigger than 1A.
>
> If I leave the circuit with the same 7A protection, what are the
> implications?
>
> Carlos
>
> --------------------------------------------------------
> Did you replace the wires? If not, then virtually no implications.
> If you put in smaller wires, then you need to use a smaller protection
device.
> Protection is for the wires - so they can't overheat in case of a short.
>
> Dennis
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: GPU connection philosophy |
At 03:44 PM 2/25/2010, you wrote:
>
>
>Bob,
>
>When I was in the military we sometimes had aircraft in the hangar
>on ground power for many hours at a time as electrics or avionics
>snags were investigated. Ground Power plugs were wired up to by-pass
>the battery, and most times (always?) the battery connector was pulled.
Yeah, I've had several folks tell me of such protocols. The
protocols have existed for doing a number of things for a long
time . . . but the rationale behind those processes remain a
mystery.
> Also, if the battery (24v Ni-Cad) was flat we took it down to the
> battery bay and got another.
I don't think ANYONE in the TC/Military world recommends
charging a flat battery while in the aircraft. This is because
certain protocols call for cap-checking any battery that's
found seriously discharged . . . particularly if the
individual who discovers the condition has no idea why
or how long the battery has been dead.
> We also used to start the aircraft every time on external power
> (unless a power rig wasn't available).
As a TC manufacturer, I'd be delighted if everyone used
ground power to start up . . . shucks, we could probably
make a battery last twice as long in service. But the
CONVENIENCE of owning your own airborne transportation
extends to maximizing convenience for jump-in-and-go.
It's a trade off.
>Perhaps this thinking has found its way by osmosis into the small
>aircraft TC community without any good reason? Perhaps its also an
>attempt to stop owners charging old wet electrolyte batteries in
>situ, with the risk of acid spillage, or worse?
I suspect you're correct. The neat thing about OBAM
aircraft, we're encouraged to understand how and
why things work with sufficient competence to craft
our own protocols.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z-11 Question |
At 09:15 PM 2/25/2010, you wrote:
>
>
>Hi Bob,
>
>Looking at Z-11/M, why is the endurance bus protected by a fuse from
>the battery bus but not the main bus? Is it just for the sake of
>the switch or something else?
Fuses, breakers, et. als. protect WIRES. They're not
well applied for the protection of hardware. There's
a long feeder from a VERY robust current source
quite capable of toasting the alternate feed path
wiring . . . hence the fuse or breaker at the battery
end. The other end is short wires that hopefully
conform with the 6" or less rule that says protection
MIGHT not be all that useful or necessary.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Circuit protection - Amps |
At 09:01 AM 2/26/2010, you wrote:
>I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp PTC.
>I replaced those by new LED nav lights, which draw about 0.5A, and
>should need a protection device not bigger than 1A.
>
>If I leave the circuit with the same 7A protection, what are the implications?
If you didn't downsize the wires, then none. The PTC
is to protect wires.
Bob . . .
________________________________________________________________________________
| Subject: | How do you reliably attach wire to a solder lug switch |
| From: | rparigor(at)suffolk.lib.ny.us |
Hi Group
Again I wish my instrument was "just a little bit
larger". I need to install a switch to reset (or turn off) my
wastegate servo for Rotax 914. It is not somewhere I want a wire fatiguing
and breaking. Rotax calls for a switchDPDT NO withmomentary
(OFF). I want ability to keep off so instead I want to use a TPDT, this
way when off I can illuminate a warning LED. The real estate I want to
place switch and indicator allows use of a miniature toggle with solder
lugs (also Perihelion switch guard and red screw on boot cover). My
question is what can I do besides double heat shrinking lugs and wires to
decrease chance of a mechanical fatigue failure? Or is double heat shrink
with wires secured within 2" adequate?
Thx.
Ron Parigoris
________________________________________________________________________________
| From: | dave.gribble(at)mchsi.com |
| Subject: | Re: GNS430 Wire Book |
forgive the minor thread hijack - but what is an AGATE wire book, and where can
it be downloaded from?
Thanks,
dave
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Thursday, February 25, 2010 8:46:56 AM GMT -06:00 US/Canada Central
Subject: Re: AeroElectric-List: GNS430 Wire Book
At 11:41 PM 2/24/2010, you wrote:
>I'm still trying to sort out my GNS430W's lack of comm. I had the
>unit bench tested here locally, and it works just fine at the
>avionics shop, so the issue must be my wiring somewhere. The wire
>book for AGATE that I've downloaded shows the 430 being hooked up
>through the GMA340. All I want to use is a simple Sigtronics
>intercom; no audio panel.
>
>The Sigtronics does not have "audio low" or "mic low" inputs. I
>believe I read somewhere that these are to be grounded, so that's
>what I did, but I can't find that reference right now.
Yes . . . when those pins are not available as
dedicated inputs, use signal or power grounds
as close to the intercom's cable connector
as practical . . .
> The Garmin manual (4.7.2.3) states that they're balanced inputs,
> and that both must be connected. I'm a bit wary of experimenting
> willy-nilly with this radio, so I haven't gone and tried tying them
> together yet.
>
>Also, the AGATE wire book shows a "Comm Mic Return" pin 8 on P4002,
>to be joined with the Comm Audio Lo. The Garmin manual simply shows
>that as a reserved or unused pin.
Hmmmm . . . I did those drawings some years ago and
a tech over in experimental flight installed the
radio. A week later I noticed that the radio was
in and working . . . but if he found any errors
in my drawing he didn't mention them. So I'm assuming
that the drawings are correct as depicted.
Is it just an audio issue? Which way . . . can't talk
or can't hear or both? Does the transmitter key when
you press the mic button.
Bob . . .
________________________________________________________________________________
| From: | "Brooks Wolfe" <slipstream(at)wavecable.com> |
| Subject: | Re: GNS430 Wire Book |
I think I found my problem -- Connectivity with the plugs in the back of
the
rack isn't too good. When I cut the panel, my thinking was to make my pa
nel
exactly as large as the GNS430 itself. The rack is flush with the backsi
de
of the panel. After figuring out that I wasn't getting a good connection
,
it occurred to me that the rack should be flush with the front side (disp
lay
side) of the panel. That little 1/8" of movement that I'd lost in the fi
rst
setup was apparently enough to keep the comm connector, P4002, from makin
g a
good solid connection.
Brooks
________________________________________________________________________________
| Subject: | Z-12 Architecture - Parallel Master Contactors |
| From: | "rckol" <rckol(at)kaehlers.com> |
In "A Short Discussion of the Endurance Bus" on page Z-2 of Rev 12A of The AeroElectric
Connection it states that "Unless you're planning TWO alternators (Z-12,
Z-13 or Z-14) then the purpose of the e-bus is to provide a minimum consumption
mode of operation in a battery only condition..."
Z-14 has no ebus
In Z-13, the ebus is tied to the output of the 8 AMP alternator and it functions
to limit the load on the alternator (as plan B) but also provides for a battery
only mode (Plan C) in the event of an unlikely simultaneous failure of both
alternator systems.
In Z-12, it seems the function of the e-bus is a battery only mode of operation
for either either of the following:
a. A Plan B in the event that an open master contactor failure renders both alternators
unusable or
b. A Plan C in the event of an unlikely failure of both alternator systems for
other reasons on the same tank of fuel.
For Z-12, if instead of an e-bus, a parallel master contactor was provided:
a. Plan B in the case of an open master contactor would be to close the parallel
contactor resulting in a fully functioning alternator(s) and
b. Plan C would be unchanged.
The cost and complexity of an extra contactor compared to an e-bus would seem to
be about a wash.
What would be the downside other than the need to thoughtfully manage the electrical
loads in Plan C?
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288452#288452
________________________________________________________________________________
| From: | "Noah" <sgninc(at)cox.net> |
I purchased an SD-20 auxiliary alternator after reading AEC a couple of years ago,
and had been planning a Z-13/20. Subsequent to this purchase and installation
on my engine, Bob has indicated on numerous occasions that this was not a
well thought out architecture, and thus was withdrawn a couple of years ago.
However, I have NEVER seen an explanation of what the concerns were regarding this
architecture, and more particularly, what its' failure modes are.
So what say ye, Bob? What did you decide that you didn't you like about this architecture?
What makes it so objectionable?
A related question regards what is "magic" about the SD-8 that allows it to be
used in the Z/13 architecture while the SD-20 has been deemed NOT compatible.
I don't have much experience analyzing schematics but when I look at Z-13/20, I
guess I just don't see what the issue is. Can someone please educate me?
Highest Regards,
Noah Forden
RV-7A
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288458#288458
________________________________________________________________________________
| Subject: | Re: Z-12 Architecture - Parallel Master Contactors |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Re: A second parallel battery contactor in lieu of an E-Bus.
The cost of the E-Bus and diode and switch and relay are relatively inexpensive
and weigh less than a second contactor and associated heavy wire. When I am
faced with a decision, I ask myself, "What is best in the long run?"
Your proposal is feasible for a backup in case of contactor failure in Z-12
(two alternators). I do not see any safety issues. You have double the chance
of leaving the master switch on. :-)
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288501#288501
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Circuit protection - Amps |
Thanks Ralph
I did the same as you and kept the old units (which I'll probably have to
toss when my bird will hit the weighing scales ... :-(), so I am maintaining
the same protection.
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Ralph E. Capen
> Sent: sexta-feira, 26 de Fevereiro de 2010 15:58
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Circuit protection - Amps
>
>
>
> The fuse is supposed to protect the wire. Shouldn't be an issue. You can
> downsize the fuse based on expected draw and any unexpected draw will pop
the
> fuse.
>
> I had similar Whelens which I replaced with LED units...kept the same fuse
as I am
> carrying one of the old units (with both lenses) as a backup in case of
hangar rash
> at a destination....I can easily swap out to my backup and the wiring is
already set-
> up.
>
>
> My .02
>
> Ralph
>
>
> -----Original Message-----
> >From: Carlos Trigo <trigo(at)mail.telepac.pt>
> >Sent: Feb 26, 2010 10:01 AM
> >To: aeroelectric-list(at)matronics.com
> >Subject: AeroElectric-List: Circuit protection - Amps
> >
> >I had Whelen Nav lights in my RV-9A, in a circuit protected by a 7Amp
PTC.
> >
> >I replaced those by new LED nav lights, which draw about 0.5A, and should
> >need a protection device not bigger than 1A.
> >
> >
> >If I leave the circuit with the same 7A protection, what are the
> >implications?
> >
> >
> >Carlos
>
________________________________________________________________________________
| From: | "Tom Barter" <kesleyelectric(at)iowatelecom.net> |
| Subject: | SD-8 self excite capacitor |
Bob,
The SD-8 that I recently purchased was supplied with a 10K mfd capacitor.
The self excite mod in the 'Connection calls for a 20-50K mfd. I seem to
remember reading that the capacitor rating was not that critical. With the
addition of the resistors and bridge rectifier, will the supplied capacitor
be satisfactory for the SD-8 to self excite?
Tom Barter
Kesley, IA
Avid Magnum
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: SD-8 self excite capacitor |
At 06:09 PM 2/27/2010, you wrote:
>Bob,
>
>The SD-8 that I recently purchased was supplied with a 10K mfd
>capacitor. The self excite mod in the 'Connection calls for a
>20-50K mfd. I seem to remember reading that the capacitor rating
>was not that critical. With the addition of the resistors and
>bridge rectifier, will the supplied capacitor be satisfactory for
>the SD-8 to self excite?
Yes.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Clearing some away some fog and fuzzy logic |
. . .
At 10:43 AM 2/26/2010, you wrote:
>
>The main issue in this debate seems to be whether to use fuses or
>circuit breakers. Like many decisions in life, there is more than
>one way to accomplish a goal. One way may have certain advantages
>over the other way, and visa-versa. Many times the decision boils
>down to a matter of personal preference; and I believe that is the case here.
It's always a personal preference but it's not
always a matter of 'let's take out a 5A breaker and
put in a 5A fuse'. There are even instances where
two 5A breakers can exhibit SIGNIFICANT differences.
It's not even a debate about which is better or
preferred but a reminder that what ever device
is being considered, confident compliance with
design goals may goe far beyond current ratings.
Some people might argue that fuses will blow quicker than circuit
breakers will trip, thus offering better protection. Although
technically true, I do not think the time difference is significant.
It's not necessarily better but it IS different.
The time-to-trip dynamics for the full gamut
of protective devices is huge . . . if you're
just protecting the wire to gear down indicator
LEDS, the differences may not be significant.
But as soon as the load offers high inrush or
transient characteristics like incandescent landing
lights, pump motors, pitot heaters, confident
application of the chosen device demands understanding.
One way to avoid nuisance blowing of fuses is to use a larger
size. For instance, an avionics manufacturer might recommend using a
1 amp fuse. If you use a 3 amp fuse instead, there will be a lot
less chance of it blowing.
I counsel rejection of the off-hand up-sizing
just to hedge one's bets. The prudent designer
doesn't wager, he strives for the sure thing.
>Quote from Bob,
> > "discussed, researched, and demonstrated not to be true."
> End Quote
>I am taking Bob's side here. The technician is basing his statement
>on rumors. Bob has done experiments with expensive lab
>equipment. I trust his work. Even if the technician is correct
>(which I doubt), I would rather ruin an alternator than have an
>over-voltage condition ruin thousands of dollars worth of avionics.
It's not about gathering followers into the
camp of any particular individual. We're not running
for office. It's about the physics of simple-ideas,
about lessons-learned, about failure-tolerant design
based on logic.
> Although the technician is highly critical of Bob's
> recommendations, I do not take his statements as being a personal attack.
I guess you've not been hanging around this List
very long my friend. The "technician" in another
life claims much in the way of qualifications for
his opinion . . . including engineering degrees.
He was asked to leave the List some years back
simply because he proved incapable or unwilling
to comport with list decorum. See:
http://www.aeroelectric.com/articles/gmcjetpilot.html
But since ALL our writings have been archived for
the future, I continue to be asked about certain
of his assertions years later. What was that we
read about 'sins of the fathers'?
> Still, he was expressing his opinions as fact and pooh-poohing
> Bob's, which is not a nice thing to do. If I say something that
> others disagree with, it is OK to tell me, as long as it is done
> diplomatically. LOL
I quite agree as do the vast majority of the List
members. This particular circumstance may well
bubble up to the surface for years to come . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>I don't have much experience analyzing schematics but when I look at
>Z-13/20, I guess I just don't see what the issue is. Can someone
>please educate me?
It's clumsy . . . my associates would
call it a kluge. Z-12 shows a well considered
integration of the SD20 into a legacy system
with an e-bus added. I'm working on a drawing
that explores another approach to tying the
SD-20 and a main alternator onto two batteries.
Build a 13/20 if you wish. It will function as
advertised. I pulled the drawing because I'm
not proud of it and I'd prefer not to be associated
with the system when and if it is used.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: How do you reliably attach wire to a solder lug |
switch
> My question is what can I do besides double heat shrinking lugs
> and wires to decrease chance of a mechanical fatigue failure? Or is
> double heat shrink with wires secured within 2" adequate?
Single 1" pieces of heat shrink should be fine.
We've never double-covered any similar joint in
a TC aircraft that I'm aware of. What part number
of switch are you using?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Circuit protection - Amps |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Assuming the circuit protection is to protect the wire...(this could be argued
but not now), let's examine some situations:
There is a specification called "Intrinsically Safe" which specifies that no circuit
protection at all is needed if the circuit cannot exceed (depends on other
factors...) about 0.2 Amperes. Google "intrisically-safe wiring" Determining
the exact limit would make a great science project for an adventurous High School
student. It involves --How many Joules does it takes to set fire to gasoline
vapour?....Ah my misspent youth...!
But the resulting lesson here is that you can limit the current through the wire
at the voltage source, perhaps the bus bar, with a suitable resistor and never
see currents of >0.2A, for a variety of useful devices like LEDs, timers, clocks,
sensors, indicators, memories and I suppose, some instruments.
Take note that intrinsically safe wiring requires special consideration when used
in bundles....and that's usually an issue in aircraft wiring.
It might be true that switch-breakers are less reliable than switches. But in my
airplane I will use switch-breakers instead of switches AND fuses OR breakers
AND the associated wiring to connect everything together.
Resettable solid state fuses also have a place, and they are perfect, if indeed,
the wire is what you want to protect.
Modern auto fuses are worlds better than glass-tube AGC and similar contraptions.
(Does Mercedes still use those awful ceramic fuses?), but it is a dictum of
technological progress that the very best old technology appears just before
it becomes completely extinct.
Fuses have had their day. You can't really make up a reason to have them at all.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288600#288600
________________________________________________________________________________
| Subject: | Re: Circuit protection - Amps |
| From: | Kevin Horton <khorton01(at)rogers.com> |
On 2010-02-28, at 10:05 , Eric M. Jones wrote:
>
> Fuses have had their day. You can't really make up a reason to have them at all.
Cost is a pretty important reason to many folks. If a technology (e.g. fuses)
does an perfectly adequate job, why pay more for some other technology (switch
breakers) that also does a perfectly adequate job?
--
Kevin Horton
RV-8
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
| Subject: | Re: Circuit protection - Amps |
Fuses have had their day. You can't really make up a reason to have them
at
all.
--------
Eric M. Jones
Totally incorrect. . . . There have been several reasons,
sited on this forum, for the use of fuses as opposed to breakers and
other
circuit protection devices. Cost, weight, availability, ease of use, are
only a few of the reasons to use fuses.
I do agree that they may not be for every application, but
for the vast majority of OBAM aircraft circuit protection applications,
they
meet the needs.
Roger
________________________________________________________________________________
| From: | "tomcostanza" <Tom(at)CostanzaAndAssociates.com> |
Bob (et al),
I'm about to wire the panel, and am wondering about the e-bus diode. In particular,
I'm looking at Z-11. It appears to me that the diode only needs to be there
when the main contactor is disengaged, and the e-bus alternate feed switch
is closed. When operating normally, the diode could be a piece of wire. So
why isn't the e-bus alternate feed switch a DPDT with one pole shorting the diode
when in "normal" operation. During normal operation, would I not drop 0.6
volts across the diode? I have found empirically, that an 0.6 volt drop equals
about a 10% deficit in the output of my comm transmitter (5w to 4.5w).
I do realize that Bob has probably forgotten more than I'll ever know about this
stuff, so am I over-thinking this? Or is there something I'm missing?
Clear skies,
-Tom
--------
Clear Skies,
Tom Costanza
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288611#288611
________________________________________________________________________________
| Subject: | Re: How do you reliably attach wire to a solder |
lug switch
| From: | rparigor(at)suffolk.lib.ny.us |
Hi Bob
Thx. for the reply.
"What can I do besides double heat
shrinking lugs and wires to decrease chance of a mechanical fatigue
failure?"
"> Single 1" pieces of heat shrink should
be fine.
> We've never double-covered any similar joint in
> a TC aircraft that I'm aware of. What part number
> of
switch are you using?"
I am usingfrom Newark C &
K - T201SHCQE - Toggle Switch.
Ron Parigoris
________________________________________________________________________________
| From: | "RV7ASask" <rv7alamb(at)sasktel.net> |
Early on I decided to go with the Z-12 architecture but as my wiring came together
I became more uncomfortable with it as I am going to be running dual Lightspeeds.
The question kept coming up where should I wire the second ignition? The first
one is directly on the Hot battery bus lead, i.e. straight to the battery. The
second was planned on the E-Bus?
Still not happy, I then decided to review the whole architecture and to change
to Z-13/8. This has not been a big change other than I am running a B&C 20A Aux
alternator.
The system is pretty well done and I do not have a relay in place for the E-Bus
Alternate feed.
I still have the 1-3 switch in place as per the Z-12 and have not added a fuselink
to the E-Bus Alternate feed.
Do I need a relay? If so why? Do I need a fuse link when the alternate feed has
a 7A fuse off the Bat Bus? Do I need a fuselink between the Aux Feed Current
Limiter and the Bat Contactor?
Thanks
David Lamb
RV7A Still wiring
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288622#288622
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Circuit protection - Amps |
>Modern auto fuses are worlds better than glass-tube AGC and similar
>contraptions. (Does Mercedes still use those awful ceramic fuses?),
>but it is a dictum of technological progress that the very best old
>technology appears just before it becomes completely extinct.
Are you expecting fuses to become extinct? They have
been around since long before Edison began to market
electron-flow. The fuse catalogs are noteworthy for
the absence of older products but still more noteworthy
for the increase in numbers of new products.
Not sure where "intrinsic safety" came from. While that
too is a study in energy management under fault conditions,
I'm not sure how it matters in conducting FMEA on our
own design goals. Finally, whether Mercedes uses or does
not use any product of any era is certainly not germane
to our deliberations.
But I cannot foresee how an elegantly simple, weak-link in
the chain of electron flow will ever be totally replaced by
panel-mounted thingys with handles on them.
>Fuses have had their day. You can't really make up a reason to have
>them at all.
"Make up a reason"? How about a low cost-of-ownership
solution for meeting design goals with an attractive
outcome of FMEA. It's a certainty that switch-breakers
do not figure favorably in that equation . . . nor do
solid state breakers. If cost, weight, panel space,
and time to install are not components of your personal
design goals, so be it. But to suggest that others on
the List are somehow outdated because they do not embrace
your goals borders on elitism . . . don't you think?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 10:57 AM 2/28/2010, you wrote:
>
>
>Bob (et al),
>
>I'm about to wire the panel, and am wondering about the e-bus
>diode. In particular, I'm looking at Z-11. It appears to me that
>the diode only needs to be there when the main contactor is
>disengaged, and the e-bus alternate feed switch is closed. When
>operating normally, the diode could be a piece of wire. So why
>isn't the e-bus alternate feed switch a DPDT with one pole shorting
>the diode when in "normal" operation.
The design goal was to minimize parts count for reducing
risk of mis-positioned switches during a re-configuration to
battery only operations. The diode absolutely prevents
back-feeding the main bus from the e-bus.
> During normal operation, would I not drop 0.6 volts across the
> diode? I have found empirically, that an 0.6 volt drop equals
> about a 10% deficit in the output of my comm transmitter (5w to 4.5w).
>
>I do realize that Bob has probably forgotten more than I'll ever
>know about this stuff, so am I over-thinking this? Or is there
>something I'm missing?
A "voltage drop" on the order of .6 to .7 volts is not significant
with respect to operation of equipment on the e-bus. That
tiny drop in output, while measureable, would not be
noticed by anyone listening to you at the other end.
Consider that the alternate feedpath to the e-bus is there to
provide 10.5 to 12.5 volts to the equipment when the alternator
is off line . . . 10.5 to 12.5 is all you're going to get out
of a battery. Nonetheless, we reasonably expect equipment on
the e-bus to function in a useful manner.
When the alternator is working, the main bus is 13.8 to 14.6
volts . . . throw away 0.7 volts in the e-bus normal feed diode
and you have 13.1 to 13.9 volts on the e-bus. Still higher
than with battery-only operations.
Bottom line is that the diode drop affects performance in no
way that anyone would notice.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 12:28 PM 2/28/2010, you wrote:
>
>Early on I decided to go with the Z-12 architecture but as my wiring
>came together I became more uncomfortable with it as I am going to
>be running dual Lightspeeds.
>
>The question kept coming up where should I wire the second ignition?
>The first one is directly on the Hot battery bus lead, i.e. straight
>to the battery. The second was planned on the E-Bus?
Or the main bus. Keep in mind that your engine runs perfectly
well on one electronic ignition. During battery only ops, I'd
turn one ignition off to reduce battery loads. In the event
of a VERY rare, dual failure (lost #1 ignition too) then you
can still close the battery contactor and deal with what is
now a more critical situation than the original plan-b.
>Still not happy, I then decided to review the whole architecture and
>to change to Z-13/8. This has not been a big change other than I am
>running a B&C 20A Aux alternator.
>
>The system is pretty well done and I do not have a relay in place
>for the E-Bus Alternate feed.
That relay is only suggested for e-bus loads larger than
7A. But if you have a 20A s/b alternator, suggest you
go with Z-12, put the #1 ignition on the battery bus,
#2 ignition on the main bus. Odds are that you'll never
have to configure for e-bus only ops.
>I still have the 1-3 switch in place as per the Z-12 and have not
>added a fuselink to the E-Bus Alternate feed.
Protecting the alternate feed wire is recommended whether
you have the relay or not. The only decision is to size that
protection commensurate with e-bus, battery only loads.
>
>Do I need a relay? If so why? Do I need a fuse link when the
>alternate feed has a 7A fuse off the Bat Bus? Do I need a fuselink
>between the Aux Feed Current Limiter and the Bat Contactor?
Suggest you research the e-bus feeder discussions
in Appendix Z notes and in the matronics archives.
Suggest also that you publish your power distribution
diagram that speaks to features of the /8 upsizing to
20A.
Bob . . .
________________________________________________________________________________
| From: | "Lapsley R. and Sandra E. Caldwell" <lrsecaldwell(at)earthlink.net> |
| Subject: | Noise in Handheld Tx signal. |
We have a problem with excessive noise occurring in an ICOM A24.
Receive is good. The noise only occurs in the transmitted signal while
the engine is running, The noise is so bad the the voice is not
understandable. If the operator is about 100 ft from the A/B with the
engine running the noise is down to a level that is acceptable.
Th hsndheld is completely independent of the a/c. Internal batteries
and operation on the rubber duckie antenna. A headset is used. Two
different A24's with different headsets exhibit the same problem.
There are no avionics in the plane except for the handheld. To
eliminate the possibility of interference from instruments or alternator
we tested with the master off and the problem still exists.
Previously the A24 was used acceptably with an open cockpit biplane, a
Murphy Renegade.
One possibility could be excessive gain using the external mike, but I
am skeptical since it was acceptable in the biplane
Any suggestions?
Roger
________________________________________________________________________________
| From: | "Mark Richards" <flagstone(at)cox.net> |
Bob:
Is it going to have 2 LR-3's or an LR-3/SB-1 combination? What's the
timeframe before we get a peek?
Thanks
Mark
----- Original Message -----
From: Robert L. Nuckolls, III
To: aeroelectric-list(at)matronics.com
Sent: Saturday, February 27, 2010 9:36 PM
Subject: Re: AeroElectric-List: Z13/20
>I don't have much experience analyzing schematics but when I look at
>Z-13/20, I guess I just don't see what the issue is. Can someone
>please educate me?
It's clumsy . . . my associates would
call it a kluge. Z-12 shows a well considered
integration of the SD20 into a legacy system
with an e-bus added. I'm working on a drawing
that explores another approach to tying the
SD-20 and a main alternator onto two batteries.
Build a 13/20 if you wish. It will function as
advertised. I pulled the drawing because I'm
not proud of it and I'd prefer not to be associated
with the system when and if it is used.
Bob . . .
________________________________________________________________________________
| From: | "Noah" <sgninc(at)cox.net> |
Bob, I appreciate the response, but from a technical perspective, it doesn't give
me much to go on.
Let me try my question from a different angle.
I prefer Z-13 over Z-12 because of the salient advantages it offers, namely that
it is a two-layered electrical system, with (as far as I can tell), very little
single point failure potential. With the aux alternator feeding the battery
directly, the main contactor is removed from the list of single point failure
modes requiring landing and fixing/replacing something. Additionally, a contactor
failure does not take BOTH alternators essentially offline, as occurs
with Z12. I believe that you yourself have said on numerous occasions that Z13
is your architecture of choice.
When I take a 6000 mile trip, I don't want a main contactor failure to mean I am
on the ground for an hour, a day, or a week waiting for a replacement. My mission
requires that I be able to fly a couple of thousand miles home, COMFORTABLY,
to replace that single failed electrical component in the comfort of my
own hangar. Unless I am mistaken somehow, Z13 allows this, and Z12 does not.
So the question I will ask again is, what is it about the SD-20 which makes it
not compatible with Z-13, while the SD-8 IS compatible?
Is it because the SD-8 is a dynamo, and needs no flash from the bus? Is it because
the lower current SD-8 driven E-bus can use a backfeed switch instead of
a relay? Something else?
I have searched the archives extensively on this topic and have never found a direct
technical response to this question, despite many builders who have asked
the question in one way or another, and who require a Z-13 architecture with
an up-sized auxiliary alternator and E-Bus, so that they can FLY COMFORTABLY
all the way home, not just to the next airport.
Z14 doesn't interest me because in my case its complexity isn't needed - all of
my critical flight instruments and nav gear have internal battery backups and
the additional weight and complexity is overkill IMHO.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288688#288688
________________________________________________________________________________
| From: | <stevei(at)carey.asn.au> |
Hi Bob and all
I'm building a Glasair Super II RG powered by a Mazda Renesis Rotary using
Tracy Crook's EC2 (injection and ignition) and EM3 (Engine monitoring) and
using standard starter and a small 40amp modern auto. So fully reliant on 1
4v source power.
I have a Radio and embedded systems background so I'm not completely ignora
nt of electrons.
I'm familiar with your Z-19 and have some general questions in order to wei
gh risks.
My questions are:
1. What are the failure modes of Aircraft Batteries?
2. What are the failure modes of auto starter motors?
3. What are the failure modes of auto alternators?
I hope these questions are firstly reasonable and not naive and can be answ
ered.
Many thanks for having already benefited from this list.
Steve Izett
Perth Western Australia
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________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 08:02 PM 2/28/2010, you wrote:
>Bob:
>
>Is it going to have 2 LR-3's or an LR-3/SB-1 combination? What's
>the timeframe before we get a peek?
I'm deliberating the ease with which a pair
of IR alternators can be incorporated into a
dual battery, dual alternator, three bus system.
The design goal embraces legacy protocols for
having all fat wires "cold" with switches OFF
and no always hot wires fused at over 7A. The
IR alternator crowbar OV (and ultimately 9011)
integration calls for a b-lead contactor. If
this contactor were mounted next to a battery
contactor it could tie an alternator to the battery
side of the battery contactor instead of the bus
side.
The simplest system would utilize two IR alternators
of any size. Adding external regulators wouldn't
drive up complexity much.
The architecture offers two battery busses
supported directly by their respective alternators.
Each would be operable independently of the other
and of the main bus. No e-bus is needed. I've
about got the drawing done but I'll be out of
town today. Might get it posted late tonight.
Bob . . .
________________________________________________________________________________
Noah,
You're trying to fit a square peg in a round hole? If you're mission is
complete and redundant reliability while flying over the generally
abandoned Kansas Territory, you've got the wrong approach.
Z-13/8 is designed for emergency redundancy and yes the lower power
SD-8. This should be read as minimum required equipment to facilitate
landing at the nearest facility (the tiny spare tire in the back of your
car has the same design goal - pretty simple eh?). Z-13 was not intended
as an all out fully redundant Rambo system, nor is it designed to
sustain the output provided by the SD-20.
Truth is, if you have the right equipment in your panel you can fly long
past the Kansas Territory running with the SD-8. I can do the same and I
am flying all electric. It doesn't get more desperate than that.
If you don't have the stomach to build out a Z-12 or Z-14 (closer to
what you want), than buy the twenty dollar contactor and throw it in the
glove box with the spare batteries.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Noah
Sent: Sunday, February 28, 2010 10:37 PM
Subject: AeroElectric-List: Re: Z13/20
Bob, I appreciate the response, but from a technical perspective, it
doesn't give me much to go on.
Let me try my question from a different angle.
I prefer Z-13 over Z-12 because of the salient advantages it offers,
namely that it is a two-layered electrical system, with (as far as I can
tell), very little single point failure potential. With the aux
alternator feeding the battery directly, the main contactor is removed
from the list of single point failure modes requiring landing and
fixing/replacing something. Additionally, a contactor failure does not
take BOTH alternators essentially offline, as occurs with Z12. I
believe that you yourself have said on numerous occasions that Z13 is
your architecture of choice.
When I take a 6000 mile trip, I don't want a main contactor failure to
mean I am on the ground for an hour, a day, or a week waiting for a
replacement. My mission requires that I be able to fly a couple of
thousand miles home, COMFORTABLY, to replace that single failed
electrical component in the comfort of my own hangar. Unless I am
mistaken somehow, Z13 allows this, and Z12 does not.
So the question I will ask again is, what is it about the SD-20 which
makes it not compatible with Z-13, while the SD-8 IS compatible?
Is it because the SD-8 is a dynamo, and needs no flash from the bus? Is
it because the lower current SD-8 driven E-bus can use a backfeed switch
instead of a relay? Something else?
I have searched the archives extensively on this topic and have never
found a direct technical response to this question, despite many
builders who have asked the question in one way or another, and who
require a Z-13 architecture with an up-sized auxiliary alternator and
E-Bus, so that they can FLY COMFORTABLY all the way home, not just to
the next airport.
Z14 doesn't interest me because in my case its complexity isn't needed -
all of my critical flight instruments and nav gear have internal battery
backups and the additional weight and complexity is overkill IMHO.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288688#288688
________________________________________________________________________________
| From: | "David E. Nelson" <david.nelson(at)pobox.com> |
| Subject: | Re: Z-11 Question |
Thank you, Bob.
/\/elson
~~ Lately my memory seems to be like a steel trap .... without any spring. ~~
On Fri, 26 Feb 2010, Robert L. Nuckolls, III wrote:
>
>
> At 09:15 PM 2/25/2010, you wrote:
>>
>>
>>
>> Hi Bob,
>>
>> Looking at Z-11/M, why is the endurance bus protected by a fuse from the
>> battery bus but not the main bus? Is it just for the sake of the switch or
>> something else?
>
> Fuses, breakers, et. als. protect WIRES. They're not
> well applied for the protection of hardware. There's
> a long feeder from a VERY robust current source
> quite capable of toasting the alternate feed path
> wiring . . . hence the fuse or breaker at the battery
> end. The other end is short wires that hopefully
> conform with the 6" or less rule that says protection
> MIGHT not be all that useful or necessary.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | James Robinson <jbr79r(at)yahoo.com> |
| Subject: | Re: Battery charging |
Hi Bob
I have been using Panasonic 17AH batteries (2) in my all electric airplane for
a few years. I usually change them out at annual time. Someone recommended
a 20 AH CSB from m&B battery company. It is the same size and a few dollars cheaper.
Any comment?
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________________________________________________________
| From: | Andrew Butler <andrewbutler(at)ireland.com> |
Hi Noah,
I'm no expert and my bird is a couple of months away from fire up, but my panel
and all electrics are finished and appear to work. Mine is based on the Z13/8
architecture.
The architecture is a template not a solution. My understanding is that the wares
being offered by the "owners" of this forum are design and engineering oriented
rather than solution oriented, hence the feeling that it is difficult to
get a straight answer when you ask a solution oriented question. A lot of time,
effort and experience has gone into fine tuning the aeroelectric templates.
Even so, there is nothing wrong with putting a SD-20 in place of the SD-8. However,
by changing one of the major components of a design template, you completely
change the profile of the architecture and the original design goals are
no longer a match (more weight, more expense etc.) and it is invalidated.
So if the design goal is to get down safe in the event of an alt failure for the
least weight and cost penalty, even if you are more than an hour from the nearest
airport, then the design that fits the bill is the Z13/8. If you want an
alt failure to be a normal mode of operation, then it is the design that you
deploy has to change, rather than the template you start with.
Andrew Butler
RV7 EI-EEO
Galway, Ireland.
----- Original Message -----
From: longg(at)pjm.com
Sent: Monday, 1 March, 2010 15:30:23 GMT +00:00 GMT Britain, Ireland, Portugal
Subject: RE: AeroElectric-List: Re: Z13/20
Noah,
You're trying to fit a square peg in a round hole? If you're mission is
complete and redundant reliability while flying over the generally
abandoned Kansas Territory, you've got the wrong approach.
Z-13/8 is designed for emergency redundancy and yes the lower power
SD-8. This should be read as minimum required equipment to facilitate
landing at the nearest facility (the tiny spare tire in the back of your
car has the same design goal - pretty simple eh?). Z-13 was not intended
as an all out fully redundant Rambo system, nor is it designed to
sustain the output provided by the SD-20.
Truth is, if you have the right equipment in your panel you can fly long
past the Kansas Territory running with the SD-8. I can do the same and I
am flying all electric. It doesn't get more desperate than that.
If you don't have the stomach to build out a Z-12 or Z-14 (closer to
what you want), than buy the twenty dollar contactor and throw it in the
glove box with the spare batteries.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Noah
Sent: Sunday, February 28, 2010 10:37 PM
Subject: AeroElectric-List: Re: Z13/20
Bob, I appreciate the response, but from a technical perspective, it
doesn't give me much to go on.
Let me try my question from a different angle.
I prefer Z-13 over Z-12 because of the salient advantages it offers,
namely that it is a two-layered electrical system, with (as far as I can
tell), very little single point failure potential. With the aux
alternator feeding the battery directly, the main contactor is removed
from the list of single point failure modes requiring landing and
fixing/replacing something. Additionally, a contactor failure does not
take BOTH alternators essentially offline, as occurs with Z12. I
believe that you yourself have said on numerous occasions that Z13 is
your architecture of choice.
When I take a 6000 mile trip, I don't want a main contactor failure to
mean I am on the ground for an hour, a day, or a week waiting for a
replacement. My mission requires that I be able to fly a couple of
thousand miles home, COMFORTABLY, to replace that single failed
electrical component in the comfort of my own hangar. Unless I am
mistaken somehow, Z13 allows this, and Z12 does not.
So the question I will ask again is, what is it about the SD-20 which
makes it not compatible with Z-13, while the SD-8 IS compatible?
Is it because the SD-8 is a dynamo, and needs no flash from the bus? Is
it because the lower current SD-8 driven E-bus can use a backfeed switch
instead of a relay? Something else?
I have searched the archives extensively on this topic and have never
found a direct technical response to this question, despite many
builders who have asked the question in one way or another, and who
require a Z-13 architecture with an up-sized auxiliary alternator and
E-Bus, so that they can FLY COMFORTABLY all the way home, not just to
the next airport.
Z14 doesn't interest me because in my case its complexity isn't needed -
all of my critical flight instruments and nav gear have internal battery
backups and the additional weight and complexity is overkill IMHO.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288688#288688
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: Battery charging |
James,
Curious why you change them out so often.
I'll assume they are fairly expensive batteries.
Do you use a "maintainer" on them on the parked days...? I use Concords
and Gill. These get maybe changed out in 5 years, but, they always have
a maintainer attached during off flying periods. When I do change them
out they are still functioning normally but, like you, there is a period
limit that one feels comfortable.
Dave
-------------------------------------------------------------------------
-------
----- Original Message -----
From: James Robinson
To: aeroelectric-list(at)matronics.com
Sent: Monday, March 01, 2010 8:44 AM
Subject: Re: AeroElectric-List: Battery charging
Hi Bob
I have been using Panasonic 17AH batteries (2) in my all electric
airplane for a few years. I usually change them out at annual time.
Someone recommended a 20 AH CSB from m&B battery company. It is the
same size and a few dollars cheaper. Any comment?
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________________________________________________________
| From: | "rckol" <rckol(at)kaehlers.com> |
Noah,
In another thread earlier this weekend I proposed the use of a second, parallel
master contactor in Z-12 instead of an E-bus to accomplish what you are looking
for. This would give you the potential to fully recover from a contactor failing
open in flight and still be set up to run off the battery through an alternate
path if need be.
You might use contactors with low holding current, like an EV-200, or a standard
contactor with the gizmo Bob is working on to reduce the holding current for
Plan C (battery only ops)
Dick Kaehler
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288794#288794
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Battery charging |
Good Afternoon Dave and James,
I am curious as to whether or not either of you run capacity checks on a
regular basis. Isn't that the way the FEDs like us to do it on certified
flying machines?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
LL22
Piper PA-20-150
In a message dated 3/1/2010 11:41:01 A.M. Central Standard Time,
skywagon(at)charter.net writes:
James,
Curious why you change them out so often.
I'll assume they are fairly expensive batteries.
Do you use a "maintainer" on them on the parked days...? I use Concords
and Gill. These get maybe changed out in 5 years, but, they always have a
maintainer attached during off flying periods. When I do change them out
they are still functioning normally but, like you, there is a period limit
that one feels comfortable.
Dave
____________________________________
----- Original Message -----
From: _James Robinson_ (mailto:jbr79r(at)yahoo.com)
(mailto:aeroelectric-list(at)matronics.com)
Sent: Monday, March 01, 2010 8:44 AM
Subject: Re: AeroElectric-List: Battery charging
Hi Bob
I have been using Panasonic 17AH batteries (2) in my all electric airplane
for a few years. I usually change them out at annual time. Someone
recommended a 20 AH CSB from m&B battery company. It is the same size and a
few dollars cheaper. Any comment?
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
(http://www.matronics.com/Navigator?AeroElectric-List)
(http://www.matronics.com/contribution)
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Battery charging |
Good Afternoon Dave and James,
I am curious as to whether or not either of you run capacity checks on a
regular basis. Isn't that the way the FEDs like us to do it on certified
flying machines?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
LL22
Piper PA-20-150
In a message dated 3/1/2010 11:41:01 A.M. Central Standard Time,
skywagon(at)charter.net writes:
James,
Curious why you change them out so often.
I'll assume they are fairly expensive batteries.
Do you use a "maintainer" on them on the parked days...? I use Concords
and Gill. These get maybe changed out in 5 years, but, they always have a
maintainer attached during off flying periods. When I do change them out
they are still functioning normally but, like you, there is a period limit
that one feels comfortable.
Dave
________________________________________________________________________________
| From: | James Robinson <jbr79r(at)yahoo.com> |
| Subject: | Re: Battery charging |
In the big scheme of things the battery is a small expense. Especially the ones
mentioned. I do not do a capacity check only because it is not something I
want to spend the time messing with. I use the removed batteries for other applicatiions.
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________
From: "BobsV35B(at)aol.com" <BobsV35B(at)aol.com>
Sent: Mon, March 1, 2010 11:22:02 AM
Subject: Re: AeroElectric-List: Battery charging
Good Afternoon Dave and James,
I am curious as to whether or not either of you run capacity checks on a
regular basis. Isn't that the way the FEDs like us to do it on certified flying
machines?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
LL22
Piper PA-20-150
In a message dated 3/1/2010 11:41:01 A.M. Central Standard Time,
skywagon(at)charter.net writes:
James,
>Curious why you change them out so often.
>I'll assume they are fairly expensive batteries.
>
>Do you use a "maintainer" on them on the parked
> days...? I use Concords and Gill. These get maybe changed out in 5
> years, but, they always have a maintainer attached during off flying
> periods. When I do change them out they are still functioning normally
> but, like you, there is a period limit that one feels
>comfortable.
>Dave
________________________________________________________________________________
| From: | "David LLoyd" <skywagon(at)charter.net> |
| Subject: | Re: Battery charging |
Ol' Bob,
Always enjoy your sage additions to this and other aviation related
lists.
To answer your question about "Capacity checking". No, I do not do a
formal check annually and probably should. I use other farmer style
method.... Example, .. my 185 is fuel injected. Every once in a while,
I don't hold my gum and tongue in the right place and miss judge a hot
start procedure especially in hot summer time. Next, what comes is
probably the hardest application for a battery.
I can misjudge once or twice a year, and the procedure to clear the
vapor lock in the injection system, clearing the engine, priming
properly and then doing the restart can make an aged battery wheeze. I
use that crude rule of thumb to determine if my battery is just not
making the juice anymore. I don't recommend it, but, it works for me.
In 40 years of flying, I have not been electron deficient.
However, I am a big advocate of using the small Maintainer type devices
to keep the float voltage at par.
David
-------------------------------------------------------------------------
-------
----- Original Message -----
From: James Robinson
To: aeroelectric-list(at)matronics.com
Sent: Monday, March 01, 2010 12:10 PM
Subject: Re: AeroElectric-List: Battery charging
In the big scheme of things the battery is a small expense.
Especially the ones mentioned. I do not do a capacity check only
because it is not something I want to spend the time messing with. I
use the removed batteries for other applicatiions.
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
-------------------------------------------------------------------------
-----
From: "BobsV35B(at)aol.com" <BobsV35B(at)aol.com>
To: aeroelectric-list(at)matronics.com
Sent: Mon, March 1, 2010 11:22:02 AM
Subject: Re: AeroElectric-List: Battery charging
Good Afternoon Dave and James,
I am curious as to whether or not either of you run capacity checks on
a regular basis. Isn't that the way the FEDs like us to do it on
certified flying machines?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
LL22
Piper PA-20-150
In a message dated 3/1/2010 11:41:01 A.M. Central Standard Time,
skywagon(at)charter.net writes:
James,
Curious why you change them out so often.
I'll assume they are fairly expensive batteries.
Do you use a "maintainer" on them on the parked days...? I use
Concords and Gill. These get maybe changed out in 5 years, but, they
always have a maintainer attached during off flying periods. When I do
change them out they are still functioning normally but, like you, there
is a period limit that one feels comfortable.
Dave
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>In another thread earlier this weekend I proposed the use of a
>second, parallel master contactor in Z-12 instead of an E-bus to
>accomplish what you are looking for. This would give you the
>potential to fully recover from a contactor failing open in flight
>and still be set up to run off the battery through an alternate path
>if need be.
The e-bus is NOT intended to back up the battery contactor.
The ENDURANCE bus philosophy supplies TWO independent power
paths to electro-whizzies considered most useful for maximizing
a limited energy resource (battery) during alternator failure.
The idea is to SUSTAIN flight battery only to airport of intended
destination or at least MUCH longer than the legacy 30 minute
rule embraced by much of TC aviation.
Contactors have an energy budget that contributes nothing to
running a radio or illuminating a map. Hence the idealized
response to a low-volts warning of shutting down all non-productive
pieces of hardware INCLUDING battery contactors until comforable
arrival with the earth is assured.
The alternate feedpath just happens to BACK up the contactor
but the purpose of the alternate feedpath is to enable sustained,
comfortable operations WITHOUT a contactor. So, if you can
demonstrably do without the contactor under one set of conditions
(loss of alternator) why carry the weight around just to back
it up in the rare event that it fails?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>Z-13/8 is designed for emergency redundancy and yes the lower power
>SD-8. This should be read as minimum required equipment to facilitate
>landing at the nearest facility (the tiny spare tire in the back of your
>car has the same design goal - pretty simple eh?). Z-13 was not intended
>as an all out fully redundant Rambo system, nor is it designed to
>sustain the output provided by the SD-20.
Actually, when the endurance-bus was first crafted in a LongEz
about 20 years ago, it was Figure Z1 (ancestor to Z-11) and
the idea was to be able to operate battery only for duration
of fuel aboard.
In other words, craft a Plan-B that used preventative maintenance
of a battery that insured its ability to power a minimal list
of goodies that could keep you on-track for perhaps hours.
As electrically dependent airplanes came along, endurance mode
loads went up which increased the size of batteries to support
it. At the same time, vacuum pumps were falling into disfavor
so the opportunity to support endurance mode loads with an 8A
enhancement was attractive, hence Z-13/8. Even better yet, if
endurance loads could be kept at or below 8A, this held the
battery's entire energy content in reserve for running more
electro-whizzies during approach to landing and without warning
the tower that "my airplane might go dark" during the landing
phase.
>Truth is, if you have the right equipment in your panel you can fly long
>past the Kansas Territory running with the SD-8. I can do the same and I
>am flying all electric. It doesn't get more desperate than that.
Exactly. In the sum total of all OBAM aircraft under
construction, there are VERY few that cannot sustain
flight on an 8A endurance budget. It only requires that
the builder/operator be willing to put some judicious
thought into what electro-whizzies are really all that
helpful in the task of conserving electrical energy.
>If you don't have the stomach to build out a Z-12 or Z-14 (closer to
>what you want), than buy the twenty dollar contactor and throw it in the
>glove box with the spare batteries.
Contactor failures are rare. Contactors ARE light (under 1#)
and depending on creativity of the installer, can be changed
out with a minimum off tools. I've had a number of builders
state that they intended to carry spares into the Canadian
north country. That isn't the ONLY equipment they carry as
a hedge against small precipitating disasters.
Our FMEA studies on electrical systems is no different
than the FEMA studies that bush pilots have been doing
on the total flight system for nearly 100 years. You trade
off empty weight for features that offset potential failures.
The real task is to not allow imagined or low risks to
drive the task into overkill . . .
Emacs!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 09:35 PM 2/28/2010, you wrote:
>Hi Bob and all
>
>I'm building a Glasair Super II RG powered by a Mazda Renesis Rotary
>using Tracy Crook's EC2 (injection and ignition) and EM3 (Engine
>monitoring) and using standard starter and a small 40amp modern
>auto. So fully reliant on 14v source power.
>I have a Radio and embedded systems background so I'm not completely
>ignorant of electrons.
>I'm familiar with your Z-19 and have some general questions in order
>to weigh risks.
>
>My questions are:
> * What are the failure modes of Aircraft Batteries?
> * What are the failure modes of auto starter motors?
> * What are the failure modes of auto alternators?
>
>I hope these questions are firstly reasonable and not naive and can
>be answered.
Probably not. The failure modes are legion. To "weigh" risks
you need failure rates to factor into a fault-tree
having calculable probabilities that will drive your
decision making processes.
In FAA parlance, one failure per million flight hours
doesn't need back up, and things that cannot be backed
up (wings falling off) need calculated rates on the
order of one per billion flight hours. The point is
that were anyone on the List willing to give you the
20 page data-dump that your question seems to seek,
you would be no closer to making rational build/buy
decisions.
It's far easier to simply ASSUME those things ARE
going to break in the time that you own the airplane.
Assuming that one of them DOES cease to be flight-worthy,
what are your plans for dealing with it in a graceful
manner. This is called failure tolerant design that
forces you to think about how you put things together.
You're further encouraged to understand and PLAN for how
you'll do without them.
The nice thing about this mode of thought relieves
you of the need to seek and purchase mil-spec, space-rated,
supper parts and HOPE they never fail. You can
buy parts from the hardware store with confidence that
any failure is not going to ruin your day.
See chapter 17 in the 'Connection.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Noise in Handheld Tx signal. |
At 06:51 PM 2/28/2010, you wrote:
>Caldwell"
>
>We have a problem with excessive noise occurring in an ICOM A24.
>Receive is good. The noise only occurs in the transmitted signal
>while the engine is running, The noise is so bad the the voice is
>not understandable. If the operator is about 100 ft from the A/B
>with the engine running the noise is down to a level that is acceptable.
>Th hsndheld is completely independent of the a/c. Internal
>batteries and operation on the rubber duckie antenna. A headset is
>used. Two different A24's with different headsets exhibit the same problem.
>
>There are no avionics in the plane except for the handheld. To
>eliminate the possibility of interference from instruments or
>alternator we tested with the master off and the problem still exists.
Then it's not electrical noise. Sounds more like acoustic
noise coming in through the microphone(s).
>Previously the A24 was used acceptably with an open cockpit biplane,
>a Murphy Renegade.
>
>One possibility could be excessive gain using the external mike, but
>I am skeptical since it was acceptable in the biplane
>
>Any suggestions?
You need to identify the nature of the noise. Props sound
different that exhausts which sound different than
ignition, strobes, EL panel inverters, etc.
If you key the hand-held with the external headset
disconnected and a tape over the built in microphone,
is it quiet then?
Bob . . .
________________________________________________________________________________
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
> Contactors have an energy budget that contributes nothing to
> running a radio or illuminating a map. Hence the idealized
> response to a low-volts warning of shutting down all non-productive
> pieces of hardware INCLUDING battery contactors until comforable
> arrival with the earth is assured.
>
> The alternate feedpath just happens to BACK up the contactor
> but the purpose of the alternate feedpath is to enable sustained,
> comfortable operations WITHOUT a contactor. So, if you can
> demonstrably do without the contactor under one set of conditions
> (loss of alternator) why carry the weight around just to back
> it up in the rare event that it fails?
>
> Bob . . .
>
>
Hi Bob. I'm glad this came up. In the Z10-8 I'm considering, wouldn't a
switch be more efficient than a relay for the E bus load, assuming a ~10
amp load? (I'm not refering to the brown out relay which I see is
necessary).
What do these little Bosch type cube relays draw?
Thanks, Tim Andres
________________________________________________________________________________
| From: | "johngoodman" <johngoodman(at)earthlink.net> |
I'm looking at using this switch - will it work in a 14v system?
John
--------
#40572 QB. Engine on, wing attach coming soon. Panel delivery soon.
N711JG reserved
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288873#288873
Attachments:
http://forums.matronics.com//files/picture_1_380.png
________________________________________________________________________________
| From: | "Noah" <sgninc(at)cox.net> |
[quote="nuckolls.bob(at)aeroelect"]
>
> ...the opportunity to support endurance mode loads with an 8A
> enhancement was attractive, hence Z-13/8. Even better yet, if
> endurance loads could be kept at or below 8A, this held the
> battery's entire energy content in reserve...
The beauty of Z-13/8, is that the endurance bus is really NOT an endurance bus,
as described above, where your range is limited to battery capacity only. Z-13/8
should really be called an UNLIMITED ENDURANCE bus because you can fly with
any single component failure (excepting battery) for MONTHS. It is not limited
to battery capacity at all, as are Z11 & Z-12. No getting stranded with
Z-13/8. Agreed?
But my technical question remains unanswered. Why does the SD-8 work in this architecture,
while the SD-20 somehow falls apart?
Why changing the capacity of either bus should FORCE a change in overall system
architecture is something that makes no sense to me, and thus far, nobody has
been willing or able to explain. This is a PURELY technical question, and requires
a PURELY technical explanation.
[quote="nuckolls.bob(at)aeroelect"]
> In the sum total of all OBAM aircraft under construction, there are VERY few
that cannot sustain flight on an 8A endurance budget. It only requires that the
builder/operator be willing to put some judicious thought into what electro-whizzies
are really all that helpful in the task of conserving electrical energy.
This misses the point entirely. Rather than trying to convince people that they
are wrong for wanting an UNLIMITED ENDURANCE bus with more capacity than 8 amps,
why not explain why a 20 amp UNLIMITED ENDURANCE bus powered by an SD-20 is,
somehow, not workable?
I'll say it again, the Z-13 is an elegant architecture. How does upsizing it
force this architecture to fall flat on its face?
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288880#288880
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>
>This misses the point entirely. Rather than trying to convince
>people that they are wrong for wanting an UNLIMITED ENDURANCE bus
>with more capacity than 8 amps, why not explain why a 20 amp
>UNLIMITED ENDURANCE bus powered by an SD-20 is, somehow, not workable?
>
>I'll say it again, the Z-13 is an elegant architecture. How does
>upsizing it force this architecture to fall flat on its face?
Z-13/20 would function as advertised. It doesn't fall on
its face . . . it's just not an elegant solution by my
personal judgment . . . I just didn't want to leave
it hanging out there with my name on it.
The SD-8 is a most adequate adjunct to expanding the
horizons on Z-11 in the endurance mode. The SD-20
is a keep-it-all running size of alternator that
encourages the e-bus to become stacked up with lots
more hardware. I think I like the way Z-8 is
coming together. It will accommodate two wound-field
alternators of any combination while supporting a pair
of batteries (with always hot busses) supported by
the two alternators totally independent of the main bus.
The FMEA is looking like the e-bus would go away
completely and the switching gets simpler.
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Battery charging |
As is normal for this list, the gentleman's question was not answered and
he was instead admonished for using his time-proven techniques (which are
not opposed by the list moderator).
I, too, am interested in an answer to James' question.
Please allow me to rephrase James' question.
Are you familiar with the M&B 20 AH CSB battery?
Have you used it in an airplane?
Is it suitable for use in an airplane?
Would you recommend it?
My technique is to change one of my two batteries each year. It is my
technique and I'm not asking for comment on my technique.
Any responses to the questions above regarding the M&B 20 AH CSB battery?
Stan Sutterfield
I have been using Panasonic 17AH batteries (2) in my all electric airplane
for
a few years. I usually change them out at annual time. Someone
recommended
a 20 AH CSB from m&B battery company. It is the same size and a few
dollars cheaper.
Any comment?
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________________________________________________________
| From: | "Noah" <sgninc(at)cox.net> |
When I have heard the term kluge, I have taken it to be a catch-all word for the
fact that a design has one or more less than desirable characteristics, or failure
modes, or performance inhibitors. Additionally, I take the term kluge
to mean that a design can be significantly simplified and still perform the same
function. Merriam Webster defines the term as a system made up of poorly matched
components.
I have repeatedly asked what are the negative implications, the failure modes,
the performance hits when using a Z-13 architecture (UNLIMITED ENDURANCE given
any single point failure) with a 20A aux alternator. None have been offered,
and this most recent response, indicating that Z-13/20 will function as advertised
seems to tell me that there are none (over and above those found with Z13/8).
Do I understand your position correctly? It this simply a case of personal
bias against any endurance bus requiring >8A because you deem it generally
unnecessary and a little more costly and a little bit heavier? Just trying to
understand your position here. Another way of saying this: are the FMEA for
both the Z-13/8 and Z-13/20 essentially equivalent / identical? If this is the
case I am still baffled by the continued strong position against Z-13/20 to
the extent that you have completely disavowed it like a red-headed bastard step-child,
pulling it from your website and other publications.
The concept of a (limited) endurance bus is a very good one certainly significantly
better than the typical spam-can fleet. But isnt the concept of an UNLIMITED
ENDURANCE bus, as afforded by Z-13 in both the 8 and 20-A varieties, significantly
better still? If so, why have you continually steered dozens of builders
interested in a Z-13 architecture with a 20A E-bus away from this architecture,
to a Z-12, with a LIMITED ENDURANCE bus, or to a Z-14, with significantly
greater complexity, cost, and weight when Z-13 offers SIMPLICITY and UNLIMITED
ENDURANCE given any probabilistic single point failure?
I still have an uneasy feeling that I must be missing something, that there must
be more to it given your continued and strong position on this, but for the
life of me, I dont know what it is.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288928#288928
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Battery charging |
Thank You David and Jim,
Just wondered as I have been using the capacity tests for the last five or
six years. I don't think it is imperative to do so, but it is interesting
I find that some batteries do fail the test before I would have normally
replaced them. As Jim mentioned. I try to use those batteries in a garden
tractor or similar non critical application.
Happy Skies,
Old Bob
In a message dated 3/1/2010 6:04:31 P.M. Central Standard Time,
skywagon(at)charter.net writes:
Ol' Bob,
Always enjoy your sage additions to this and other aviation related lists.
To answer your question about "Capacity checking". No, I do not do a
formal check annually and probably should. I use other farmer style method....
Example, .. my 185 is fuel injected. Every once in a while, I don't hold
my gum and tongue in the right place and miss judge a hot start procedure
especially in hot summer time. Next, what comes is probably the hardest
application for a battery.
I can misjudge once or twice a year, and the procedure to clear the vapor
lock in the injection system, clearing the engine, priming properly and
then doing the restart can make an aged battery wheeze. I use that crude rule
of thumb to determine if my battery is just not making the juice anymore.
I don't recommend it, but, it works for me. In 40 years of flying, I have
not been electron deficient.
However, I am a big advocate of using the small Maintainer type devices to
keep the float voltage at par.
David
____________________________________
----- Original Message -----
From: _James Robinson_ (mailto:jbr79r(at)yahoo.com)
(mailto:aeroelectric-list(at)matronics.com)
Sent: Monday, March 01, 2010 12:10 PM
Subject: Re: AeroElectric-List: Battery charging
In the big scheme of things the battery is a small expense. Especially
the ones mentioned. I do not do a capacity check only because it is not
something I want to spend the time messing with. I use the removed batteries
for other applications.
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
____________________________________
From: "_BobsV35B(at)aol.com_ (mailto:BobsV35B(at)aol.com) " <_BobsV35B(at)aol.com_
(mailto:BobsV35B(at)aol.com) >
Sent: Mon, March 1, 2010 11:22:02 AM
Subject: Re: AeroElectric-List: Battery charging
Good Afternoon Dave and James,
I am curious as to whether or not either of you run capacity checks on a
regular basis. Isn't that the way the FEDs like us to do it on certified
flying machines?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
LL22
Piper PA-20-150
In a message dated 3/1/2010 11:41:01 A.M. Central Standard Time,
skywagon(at)charter.net writes:
James,
Curious why you change them out so often.
I'll assume they are fairly expensive batteries.
Do you use a "maintainer" on them on the parked days...? I use Concords
and Gill. These get maybe changed out in 5 years, but, they always have a
maintainer attached during off flying periods. When I do change them out
they are still functioning normally but, like you, there is a period limit
that one feels comfortable.
Dave
________________________________________________________________________________
| From: | "jonlaury" <jonlaury(at)impulse.net> |
longg(at)pjm.com wrote:
> Noah,
>
> snip.... Z-13 was not intended
> as an all out fully redundant Rambo system, nor is it designed to
> sustain the output provided by the SD-20.
> --
Z-13/8 may not be "designed" for the SD-20, but is the additional 12 amps (or in
my case, 22a ) going to jeopardize the system function, assuming the appropriate
size wire, fuses, etc.?
I just don't see how a larger alternator makes any difference to the functioning
of the system.
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288945#288945
________________________________________________________________________________
| Subject: | Re: Battery charging |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Hey Stan,
Possibly the reason no answer was given was because M&B sells lots
of different batteries, but one of us who have to expend some effort to
figure out what kind of battery it is.
I did so, just because of all the chatter.
It is not a M&B battery, it is a CSB sealed Lead Acid battery
Does not say gel vs immobilized in the little ad.
Its probably ok but I have no experience with the CSB brand,
so you will be a test pilot! After you use it a year let us know
what you found. Half price off an Odessey is not bad unless there is
a reason for the cheapness.
As for swapping out batteries every year: what a waste of money!
Driven by FUD, as the IBMers used to say: Fear, Uncertainty, and Doubt.
If you learn a bit about batteries, then maybe you can still use
premium quality Pana batteries and only swap them every other year!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288972#288972
________________________________________________________________________________
| From: | Dan Brown <dan(at)familybrown.org> |
| Subject: | Daniels positioner question |
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Hash: SHA1
I bought a Daniels AFM8 crimper from eBay, which came with three
positioners. Two were K42s, which I can use. The other one is a K187.
I can't really find any information about its application. It appears
that it's intended for a connector from Continental Connector Company,
but that isn't telling me much.
I'm pretty sure it isn't something I'm going to need, so I'm looking to
sell it--just wanting to describe it as completely as possible.
- --
Dan Brown, KE6MKS, dan(at)familybrown.org
"Since all the world is but a story, it were well for thee to buy the
more enduring story rather than the story that is less enduring."
-- The Judgment of St. Colum Cille
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________________________________________________________________________________
| From: | Joe Dubner <jdubner(at)yahoo.com> |
| Subject: | Re: Battery charging |
BobsV35B(at)aol.com wrote:
[snip]
> I find that some batteries do fail the test before I would have normally
> replaced them. As Jim mentioned. I try to use those batteries in a garden
> tractor or similar non critical application.
Me too, Old Bob . (Image of my drill with an external 35AH battery
attached). Seriously, this is a cost-effective substitute for those
expensive replacement NiCad battery packs. I just can't bear to throw
away even a Harbor Freight $20 drill motor and it very useful at times.
The fine print: yes, this is a 12V battery and a 9.6V drill fed with
some 18AWG power cord I had lying around. The drill motor likes it just
fine. The thing should be fused but I consider the entire power cord to
be a "fusible link".
--
Joe
Independence, OR
http://www.mail2600.com/position
http://www.mail2600.com/cgi-bin/webcam.cgi
________________________________________________________________________________
| From: | "RV7ASask" <rv7alamb(at)sasktel.net> |
I think my original post on Z12/Z13 may have helped start this thread. As I indicated
I have changed to a Z13 with a 20A Aux Alternator.
Attached is my version of the schematic. There are some details missing of course
but this is what the system is built around.
My wiring is almost done but I am open to constructive criticism.
Thanks
David Lamb
RV7A Still wiring.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=288993#288993
Attachments:
http://forums.matronics.com//files/all_elec_schematic_178.pdf
________________________________________________________________________________
| From: | "David Barrett" <flylists(at)dbarrett.net> |
| Subject: | Re: Battery charging |
This thread piqued my curiosity, so I did a little research. The Panasonic &
CSB batteries have similar specs apart from the 17/20 AH rating curve. Their
operating range has a lower limit of -15 C (5 F), and an internal resistance
of 12-13 mOhms. Internal resistance and temperature range will have a large
impact on cold-weather starting. The CSB is limited to a max of 230 A for 5
sec. The Panasonic specs do not provide this information, but I suspect it
is similar to CSB due to the internal resistance.
At the other end of the battery spectrum is the Osyssey 680. It has a -40 C
(-40 F) lower temperature limit, and 7.5 mOhm internal resistance. They
claim a 680 A discharge rate for 5 sec. and 400 A for 30 seconds. The longer
time AH capacity is typical for a 16 AH battery. EnerSys (parent company)
also produces the Genesis product line at the same plant as Odyssey in
Warrensburg, Missouri. The Genesis G12V16EP happens to have the same case
design/dimensions, terminals, and electrical specs as the Odyssey 680, but
at a somewhat lower price. They may not be identical, but it's hard to tell
any difference. Aviation is on the Genesis application list, so this might
be a good value. http://tnrbatteries.com/geg11.html Odyssey and Genesis
batteries also have a two year replacement warranty rather than the typical
one year.
Spec sheets (note that Odyssey & Genesis have every detail):
Panasonic:
http://www.panasonic.com/industrial/includes/pdf/Panasonic_VRLA_LC-PD1217P.p
df
CSB: http://www.csb-battery.com/upfiles/dow01242375277.pdf
Odyssey: http://www.odysseybatteries.com/files/techbook.pdf
Genesis: http://www.enersysreservepower.com/documents/US_GPL_SG_001_0303.pdf
If you're looking at the Panasonic and/or CSB batteries, there are plenty of
other batteries with similar specs that are even lower cost. Among other
things, I'd pay close attention to the terminal style. Make sure that
vibration won't weaken the terminal over time. Many of these batteries
differ only by the label on top.
If starting current isn't an issue with you, the lower cost batteries may
well be the best value. If you don't want to be stranded with a dead
battery in a cold climate or after a failed hot start, cranking amps will be
a large part of your decision process. YMMV
David Barrett
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Speedy11(at)aol.com
Sent: Tuesday, March 02, 2010 10:11 AM
Subject: AeroElectric-List: Re: Battery charging
As is normal for this list, the gentleman's question was not answered and he
was instead admonished for using his time-proven techniques (which are not
opposed by the list moderator).
I, too, am interested in an answer to James' question.
Please allow me to rephrase James' question.
Are you familiar with the M&B 20 AH CSB battery?
Have you used it in an airplane?
Is it suitable for use in an airplane?
Would you recommend it?
My technique is to change one of my two batteries each year. It is my
technique and I'm not asking for comment on my technique.
Any responses to the questions above regarding the M&B 20 AH CSB battery?
Stan Sutterfield
I have been using Panasonic 17AH batteries (2) in my all electric airplane
for
a few years. I usually change them out at annual time. Someone
recommended
a 20 AH CSB from m&B battery company. It is the same size and a few dollars
cheaper.
Any comment?
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "user9253" <fran4sew(at)banyanol.com> |
> I'm looking at using this switch - will it work in a 14v system?
John,
Yes, it will work. Voltage is not an issue for this switch in your airplane.
Current is the issue. The picture does not specify 250V AC or DC. I will assume
that it is AC. I think it should be safe to use this switch to handle up
to 5 amps at 14VDC. A switch will not immediately self-destruct if operated slightly
above its rating. But its life will be shortened. How much current do
you want to control with this switch and what type of load is it?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289004#289004
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 12:33 PM 3/2/2010, you wrote:
>
>
>longg(at)pjm.com wrote:
> > Noah,
> >
> > snip.... Z-13 was not intended
> > as an all out fully redundant Rambo system, nor is it designed to
> > sustain the output provided by the SD-20.
> > --
>
>
>Z-13/8 may not be "designed" for the SD-20, but is the additional 12
>amps (or in my case, 22a ) going to jeopardize the system function,
>assuming the appropriate size wire, fuses, etc.?
>I just don't see how a larger alternator makes any difference to the
>functioning of the system.
And as I said, it will function as advertised. I've
seen V-6's in VW bugs and they too function as
advertised. I'm in no way attempting to talk you
out of doing what ever you wish. I was trying to
convey the idea that while Z-13/20 was my design
prompted by some discussions at the time . . . I
was not proud of it and withdrew it. In my opinion
it argued with design goals for Z-13/8 as a low
cost, light weight, simple excursion into all-electric
aircraft. If you are committed to the notion of running
an SD-20, then I think there are better ways to do it.
But, do as you wish with confidence . . . but please
don't call it Z-13/20. That would suggest the configuration
is something that I have offered as a elegant recipe
for success. I wouldn't put a 4-bbl carburetor on
my Chevy 6-cyl but it no doubt could be made to
function but with little more risk than the stock
carb would offer.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Daniels positioner question |
At 05:23 PM 3/2/2010, you wrote:
>
>-----BEGIN PGP SIGNED MESSAGE-----
>Hash: SHA1
>
>I bought a Daniels AFM8 crimper from eBay, which came with three
>positioners. Two were K42s, which I can use. The other one is a K187.
> I can't really find any information about its application. It appears
>that it's intended for a connector from Continental Connector Company,
>but that isn't telling me much.
>
>I'm pretty sure it isn't something I'm going to need, so I'm looking to
>sell it--just wanting to describe it as completely as possible.
Hmmm . . . Page 15 of . . .
http://aeroelectric.com/Mfgr_Data/Tools/Daniels/ConnectorToolingGuide.pdf
speaks to the K13-1, K41 and K42 positioners in the 20 and
22AWG d-sub world. But a search of the document says
nothing about the K187.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
Might a switch be more efficient than a relay for the E bus load,
assuming a ~10
amp load? (I'm not refering to the brown out relay which I see is
necessary).
Certainly more efficient since the switch does not
draw current to keep it closed. But the relay is
called for when it is functioning as a mini-contactor
located adjacent to the battery bus. If you can reach
a switch located there, then you could consider the
subsitution.
What do these little Bosch type cube relays draw?
Thanks, Tim Andres
About 100 mA depending on manufacturer and some
other details. These are not big energy hogs.
Bob . . .
________________________________________________________________________________
| From: | "rckol" <rckol(at)kaehlers.com> |
David,
Regarding your schematic, If you are planning to run a heavily loaded e-bus (yours
is fused for 15 amps), I think you are going to want to use the heavy duty
e-bus switching with a relay (Z-32). I think this has been recommended for anything
over 7 amps.
--------
rck
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289012#289012
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>
>I have repeatedly asked what are the negative
>implications, the failure modes, the performance
>hits when using a Z-13 architecture
>(UNLIMITED ENDURANCE given any single point failure) with a 20A aux alternator.
Actually, it's not unlimited endurance, you're still going
to run out of fuel. You just don't have to come down because
you're out of electrons.
> None have been offered, and this most recent
> response, indicating that Z-13/20 will
> function as advertised seems to tell me that
> there are none (over and above those found with
> Z13/8). Do I understand your position correctly?
Yes
> It this simply a case of personal bias against
> any endurance bus requiring >8A because you
> deem it generally unnecessary and a little more
> costly and a little bit heavier? Just trying to understand your position here.
It's not about the SD-20 vs any other alternator. It's
about substitutions in the recipe for success represented
by Z-13/8.
> Another way of saying this: are the FMEA for
> both the Z-13/8 and Z-13/20 essentially equivalent / identical?
Yes . . .
> If this is the case I am still baffled by the
> continued strong position against Z-13/20 to
> the extent that you have completely disavowed
> it like a red-headed bastard step-child,
> pulling it from your website and other publications.
If you could fit 55W halogen bulbs to your tail
lights, it would certainly ALTER the way the
tail lights function with respect to their
original design goals.
The folks who spent considerable time figuring
out the most cost effective ways to offer functional
tail lights would probably prefer that you did not
credit them with the idea of 'upgrading' to 55W
bulbs. It's just that simple.
I've received drawings in the mail where builders
have claimed to base their creation on one of the
Z-figures . . . or perhaps a stirring together of
several Z-figures. They're hopeful that I'll somehow
bless their creation or offer what ever "corrections"
are deemed necessary. I have to decline to debug
their NEW system as part of my commitment to the
'Connection and this List . . . and suggest that
they commission me at my usual rate to customize
a system to their design goals.
>I still have an uneasy feeling that I must be
>missing something, that there must be more to it
>given your continued and strong position on
>this, but for the life of me, I dont know what it is.
My position is simple. I've offered a number of
suggestions for architectures that include notes
describing design goals, functionality and sizing
of components. One COULD integrate two 100A
alternators into something that looks like Z-13/8
but it's NOT Z-13/8, or Z-13/100 . . . it's
something else.
Just because Bob Nuckolls doesn't want to lend
his "blessing" to such a system doesn't mean
that it's unsafe, or even difficult to do. What
it does mean that THIS particular combination
of hardware doesn't fit a recipe for success
that's been matched to an airframe and a mission
in concert with the spirit and intent of the
AeroElectric Connection and this List.
I'm not the FAA. I have no ability or slightest
desire to twist anyone's arm to do or not do
anything. There are plenty of folks here on the
List who can help sort out errors of sizing,
failure modes or functionality. But as soon as
any one of us offers such service, does this
translate into any sort of "blessing" by those
who offered assistance? By the same token,
if one wishes to stir new ingredients into
what used to look like Z-13/8, then we're
talking about a new system.
I've been thrashing through the design studies
for a two-alternator, two-battery system that
makes sense for an electrically dependent airplane
with failure tolerance loads that far exceed
8A . . . I.e., an SD-20 or even larger alternators
can be considered when necessary to meet anticipated
failure modes. It will be Z-8. It will be something
I'll happily stand up to defend and modify as
necessary to correct flaws of design/logic.
Bob . . .
________________________________________________________________________________
| From: | James Robinson <jbr79r(at)yahoo.com> |
| Subject: | Re: Battery charging |
Thank you David=0AThis was the type info I was hoping for. I have used the
Panasonic for 4 years with no real problem, however I have dual electronic
ignition and I am usually hangered so starts are very easy. However, it
is always good to be informed and with alternatives.=0AJim=0A=0A James Robi
nson=0AGlasair lll N79R=0ASpanish Fork UT U77=0A=0A=0A=0A=0A_____________
___________________=0AFrom: David Barrett <flylists(at)dbarrett.net>=0ATo: aer
oelectric-list(at)matronics.com=0ASent: Tue, March 2, 2010 6:39:46 PM=0ASubjec
t: RE: AeroElectric-List: Re: Battery charging =0A=0A =0AThis thread piqued
my curiosity, so I did a little research. The=0APanasonic & CSB batteries
have similar specs apart from the 17/20 AH rating=0Acurve. Their operating
range has a lower limit of -15 C (5 F), and an internal=0Aresistance of 12-
13 mOhms. Internal resistance and temperature range will have=0Aa large imp
act on cold-weather starting. The CSB is limited to a max of 230 A=0Afor 5
sec. The Panasonic specs do not provide this information, but I suspect=0Ai
t is similar to CSB due to the internal resistance.=0A =0AAt the other end
of the battery spectrum is the Osyssey 680. It=0Ahas a -40 C (-40 F) lower
temperature limit, and 7.5 mOhm internal resistance. They=0Aclaim a 680 A d
ischarge rate for 5 sec. and 400 A for 30 seconds. The longer=0Atime AH cap
acity is typical for a 16 AH battery. EnerSys (parent company) also=0Aprodu
ces the Genesis product line at the same plant as Odyssey in Warrensburg,
=0AMissouri. The Genesis G12V16EP happens to have the same case design/dime
nsions,=0Aterminals, and electrical specs as the Odyssey 680, but at a some
what lower price.=0AThey may not be identical, but it=99s hard to tel
l any difference. Aviation=0Ais on the Genesis application list, so this mi
ght be a good value. http://tnrbatteries.com/geg11.html Odyssey and Genesis
batteries also have a two year replacement warranty rather=0Athan the typi
cal one year.=0A =0ASpec sheets (note that Odyssey & Genesis have every det
ail):=0APanasonic: http://www.panasonic.com/industrial/includes/pdf/Panason
ic_VRLA_LC-PD1217P.pdf=0ACSB: http://www.csb-battery.com/upfiles/dow0124237
5277.pdf=0AOdyssey: http://www.odysseybatteries.com/files/techbook.pdf=0AGe
nesis: http://www.enersysreservepower.com/documents/US_GPL_SG_001_0303.pdf
=0A =0AIf you=99re looking at the Panasonic and/or CSB batteries,=0At
here are plenty of other batteries with similar specs that are even lower
=0Acost. Among other things, I=99d pay close attention to the termina
l style.=0AMake sure that vibration won=99t weaken the terminal over
time. Many of=0Athese batteries differ only by the label on top. =0A =0AIf
starting current isn=99t an issue with you, the lower=0Acost batterie
s may well be the best value. If you don=99t want to be=0Astranded w
ith a dead battery in a cold climate or after a failed hot start,=0Acrankin
g amps will be a large part of your decision process. YMMV=0A =0ADavid Barr
ett=0A =0A =0A =0AFrom:owner-aeroelectric-list-server(at)matronics.com=0A[mail
to:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Speedy11(at)aol.
com=0ASent: Tuesday, March 02, 2010 10:11 AM=0ATo: aeroelectric-list@matron
ics.com=0ASubject: AeroElectric-List: Re: Battery charging =0A =0AAs is nor
mal for this list, the gentleman's question was not=0Aanswered and he was i
nstead admonished for using his time-proven techniques=0A(which are not opp
osed by the list moderator).=0AI, too, am interested in an answer to James'
question.=0APlease allow me to rephrase James' question.=0AAre you familia
r with the M&B 20 AH CSB battery?=0AHave you used it in an airplane?=0AIs i
t suitable for use in an airplane?=0AWould you recommend it?=0AMy technique
is to change one of my two batteries each year. =0AIt is my technique and
I'm not asking for comment on my technique.=0AAny responses to the question
s above regarding the M&B 20 AH=0ACSB battery?=0AStan Sutterfield=0A =0A>
=0A>I have been using Panasonic 17AH batteries (2) in my all electric=0A>ai
rplane for=0A>>a few years. I usually change them out at annual time. =0A
>Someone recommended=0A>>a 20 AH CSB from m&B battery company. It is the s
ame size and a few=0A>dollars cheaper.=0A>>Any comment?=0A>>Jim=0A>=0A>>Jam
===============
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Battery charging |
>As for swapping out batteries every year: what a waste of money!
>Driven by FUD, as the IBMers used to say: Fear, Uncertainty, and Doubt.
>If you learn a bit about batteries, then maybe you can still use
>premium quality Pana batteries and only swap them every other year!
Those who choose to swap out every year should
be doing so precisely because it is NOT a waste of
$time$.
Every new development program I participate in
gets carefully studied to deduce cost-of-ownership.
When it comes to battery maintenance, you
have to decide what YOUR $time$ is worth to do
the extra functions required to guarantee battery
performance. If you're retired and have nothing
better to do than go through the cap-check exercise
periodically, then perhaps a premium battery and
attendant maintenance costs are comfortable to
contemplate.
On the other hand, if you buy the least expensive
battery you can find and simply swap them out
with some logic . . . like new main battery every
year and move main battery to the aux battery slot.
Now for the cost of a new battery you've saved the
$time$ and test equipment to do a cap check and your
confidence level in battery performance is quite
high.
This isn't about fear, uncertainty and doubt.
It's about having no doubts whatsoever based
on an activity that satisfies design goals
and makes economic sense. It doesn't apply to
everyone. For the guy who flies day-vfr to
go rubber-necking, shucks . . . he can run
a battery 'til it croaks. Cost of ownership
is very low. But if you've installed an e-bus
because it offers some capabilities for extended
alternator-out operations, there's a whole
new set of variables and solutions to consider
. . . which may or may not included a new
battery every year.
Bob . . .
________________________________________________________________________________
| From: | <stevei(at)carey.asn.au> |
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________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "johngoodman" <johngoodman(at)earthlink.net> |
> The picture does not specify 250V AC or DC. I will assume that it is AC. I
think it should be safe to use this switch to handle up to 5 amps at 14VDC. A
switch will not immediately self-destruct if operated slightly above its rating.
But its life will be shortened. How much current do you want to control
with this switch and what type of load is it?
> Joe
I want to use it for Coil Power for a GearedDrives LS1 V8 engine in an RV-10. I'm
not sure what the Coil actually draws but the wire is protected by a 15 amp
fuse. The wire from the engine looks like a 14 or 16awg. I'll have to look into
the actual draw, but this switch will probably not work since I need reliability.
Thanks for the reply,
John
--------
#40572 QB. Engine on, wing attach coming soon. Panel delivery soon.
N711JG reserved
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289034#289034
________________________________________________________________________________
| From: | "user9253" <fran4sew(at)banyanol.com> |
David Lamb,
I agree with rck that a relay is better than a switch between the battery and the
E-Bus. RCK mentioned the current handling abilities of the switch. There
is another issue: In case of smoke in the cockpit, there is no way to shut off
power to the E-Bus switch. A relay will give you the ability to open the circuit
on the engine side of the firewall.
The ANL fuse is on the wrong end of the #10 wire. A fuse and a fuselink are
not both needed, although having both does not hurt anything. The protection
device should be as close as practical to the battery contactor. The intent is
to prevent excessive battery current in case of a short circuit. No fuse is
required to protect the alternator output because the alternator current is self
limiting.
Is there over-voltage protection for the main alternator?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289041#289041
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Battery charging |
Ira,
Good points, all.
If I'm going to ask an opinion of someone on the list, then I certainly
must provide accurate information - or expect no answer.
I'm using Odessey and happy with it so far. I have no intention of
changing at this time. But, I was interested in the answer to the proposed
question. I am always interested in a less expensive, but adequate replacements
for equipment.
Perhaps changing a battery each year is a waste of money. And I've been
called an old FUDdy before, but it is certainly not out of fear,
uncertainty, or doubt.
I change a battery a year because:
1. It is recommended by an expert in the field - Electric Bob
2. My ignorance dictates that I listen to the experts
3. It establishes a reasonable means to avoid failure
4. It is not overly expensive
5. The batteries are used in other equipment and not wasted
6. The oldest battery at any moment in my RV is 2 years.
7. I don't have to bother with capacity checks
I also change my tires before they fail. Anyone who wants the old ones
just let me know.
I change my hoses before they fail. Anybody want the old ones?
I don't like being stranded in remote locations because I tried to stretch
the life of consumables such as batteries.
Just call me an old fuddy.
Ira, thanks for researching the correct info on the battery and providing
your opinion. I appreciate it.
It appears from your comment that you prefer Panasonic batteries. Which
model do you use? Why do you believe that battery is better than an
Odessey? Does it have more AH capacity? Does it have faston tabs or screw on
terminals?
Your suggestion of replacing a battery every two years seems like a
reasonable thing to do - especially if one charges the batteries to capacity
periodically.
Regards,
Stan Sutterfield
Possibly the reason no answer was given was because M&B sells lots
of different batteries, but one of us who have to expend some effort to
figure out what kind of battery it is.
I did so, just because of all the chatter.
It is not a M&B battery, it is a CSB sealed Lead Acid battery
Does not say gel vs immobilized in the little ad.
Its probably ok but I have no experience with the CSB brand,
so you will be a test pilot! After you use it a year let us know
what you found. Half price off an Odessey is not bad unless there is
a reason for the cheapness.
As for swapping out batteries every year: what a waste of money!
Driven by FUD, as the IBMers used to say: Fear, Uncertainty, and Doubt.
If you learn a bit about batteries, then maybe you can still use
premium quality Pana batteries and only swap them every other year!
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 12:42 AM 3/3/2010, you wrote:
Thanks Bob
I get the freedom that "expecting things to
break" brings. That is very helpful, so thanks.
We all must make a call between no backup and the
backup of the backup to the Nth order.
Many years ago I was a tech working on the Perth Airport ILS system.
All I can remember is that it was the arbiter
that decided which system was functioning
correctly and which was failing, was most often
the part that failed and took the ILS system offline!
What level of redundancy does one go to before
the backups defeat the original purpose and intent.
Yeah. I had an opportunity to craft and install the
cockpit mounted controller for a series of explosively
deployed recovery parachutes in flight test aircraft.
In fact, I'm presently tasked with doing the 4th
such installation for Hawker-Beech.
The design I replaced was horribly complex made so
by some desire to monitor all features of a redundant
and sometimes quad redundant system. Failures were
displayed on an LCD screen. Over a year into the design,
the system could not be made to work because of the
monitoring system kept raising alarms . . . and the
control system ultimately glitched one night and
launched the 'chute in the hangar.
The guys in the Targets group got together and built
one in two weeks.
http://aeroelectric.com/Pictures/Misc/Recovery_Parachute_Controller.jpg
Simple array of relays, solid state sequencer, failure
tolerant, preflight testable, very low comparative
parts count. A little brother to that controller
is on my bench right now awaiting a modern AC mains
powered battery maintainer. A review of the service
history of past installations revealed a lot of replaced
batteries. Seems the crews were pulling the breaker
from ship's DC power when the system was being
"disabled". Then when needed next time, the internal
battery wasn't fully charged.
I'm building a battery maintainer into the controller
with a placard that it be plugged in at least 1 hour
in the 48 hours preceding a flight where the
parachute will be armed.
I suppose where I am still pondering is, given
your systems make sense for aircraft batteries,
alternator/generators and starters (I understand
to be technologically challenged but may be
miss informed), how would they change (if any)
given modern alternators, starters etc? (My
question predicates (foolishly) that all modern
equipment is equal in reliability!!!???)
It's an absolute fact that modern vehicular DC
power components of all stripes are longer lived
and more robust than their ancestors. So yes,
one can comfortably state that reliability of
components has increased . . . in virtually
all technologies and brands.
Perhaps, even if the mean time between failures
has quadrupled in modern equipment the risks still demand your backup systems.
Absolutely.
It's been my observation that the vast majority
of electrical systems unhappiness in OBAM aircraft
(and a substantial number of TC aircraft) DOES
NOT originate in ABILITY OF ANY PART TO DO ITS JOB.
Most problems arise from mis-application of parts and
poor process. Of course, all parts have service
lives and will ultimately cease to function.
From a systems perspective, reliability arguments
that focus on parts are academic and non-productive.
Resolution of such arguments depends heavily on statistical
data derived from laboratory tests that may or may
not accurately mimic service conditions. This is
ESPECIALLY true when service conditions are defined
by the knowledge, resources and skill sets of
the designer/installer.
That's why I started focusing on SYSTEM reliability
through failure mode effects analysis and designs
tolerant of failures. Once this relatively simple skill
was mastered, it mattered little where one
purchases parts. We're now free to concentrate
on the weakest links the OBAM aircraft fabrication
chain . . . knowledge, resources and skill set
of the builder. This is one area where process
trumps science every day.
Again, thanks for the help on the journey and the
decision making that lies at every turn.
My pleasure sir . . .
Bob . . .
________________________________________________________________________________
| Subject: | Loadmeter Shunt 10 amp |
Can you folks recommend (a link to) a loadmeter shunt for a 10 amp
application (SD-8)? I see B & C has from 20 and up. I tried digi-key but
that place is like sorting through my attic. I prefer the closed type so
I can use it inside my panel.
Thanks,
Glenn
________________________________________________________________________________
| From: | <stevei(at)carey.asn.au> |
Once again, thanks Bob, these fundamentals will steer the required decision
s in the right direction.
Steve Izett
Perth WA
On 3/03/10 11:07 PM, "Robert L. Nuckolls, III" wrote:
s.bob(at)aeroelectric.com>
At 12:42 AM 3/3/2010, you wrote:
Thanks Bob
I get the freedom that "expecting things to
break" brings. That is very helpful, so thanks.
We all must make a call between no backup and the
backup of the backup to the Nth order.
Many years ago I was a tech working on the Perth Airport ILS system.
All I can remember is that it was the arbiter
that decided which system was functioning
correctly and which was failing, was most often
the part that failed and took the ILS system offline!
What level of redundancy does one go to before
the backups defeat the original purpose and intent.
Yeah. I had an opportunity to craft and install the
cockpit mounted controller for a series of explosively
deployed recovery parachutes in flight test aircraft.
In fact, I'm presently tasked with doing the 4th
such installation for Hawker-Beech.
The design I replaced was horribly complex made so
by some desire to monitor all features of a redundant
and sometimes quad redundant system. Failures were
displayed on an LCD screen. Over a year into the design,
the system could not be made to work because of the
monitoring system kept raising alarms . . . and the
control system ultimately glitched one night and
launched the 'chute in the hangar.
The guys in the Targets group got together and built
one in two weeks.
http://aeroelectric.com/Pictures/Misc/Recovery_Parachute_Controller.jpg
Simple array of relays, solid state sequencer, failure
tolerant, preflight testable, very low comparative
parts count. A little brother to that controller
is on my bench right now awaiting a modern AC mains
powered battery maintainer. A review of the service
history of past installations revealed a lot of replaced
batteries. Seems the crews were pulling the breaker
from ship's DC power when the system was being
"disabled". Then when needed next time, the internal
battery wasn't fully charged.
I'm building a battery maintainer into the controller
with a placard that it be plugged in at least 1 hour
in the 48 hours preceding a flight where the
parachute will be armed.
I suppose where I am still pondering is, given
your systems make sense for aircraft batteries,
alternator/generators and starters (I understand
to be technologically challenged - but may be
miss informed), how would they change (if any)
given modern alternators, starters etc? (My
question predicates (foolishly) that all modern
equipment is equal in reliability!!!???)
It's an absolute fact that modern vehicular DC
power components of all stripes are longer lived
and more robust than their ancestors. So yes,
one can comfortably state that reliability of
components has increased . . . in virtually
all technologies and brands.
Perhaps, even if the mean time between failures
has quadrupled in modern equipment the risks still demand your backup syste
ms.
Absolutely.
It's been my observation that the vast majority
of electrical systems unhappiness in OBAM aircraft
(and a substantial number of TC aircraft) DOES
NOT originate in ABILITY OF ANY PART TO DO ITS JOB.
Most problems arise from mis-application of parts and
poor process. Of course, all parts have service
lives and will ultimately cease to function.
From a systems perspective, reliability arguments
that focus on parts are academic and non-productive.
Resolution of such arguments depends heavily on statistical
data derived from laboratory tests that may or may
not accurately mimic service conditions. This is
ESPECIALLY true when service conditions are defined
by the knowledge, resources and skill sets of
the designer/installer.
That's why I started focusing on SYSTEM reliability
through failure mode effects analysis and designs
tolerant of failures. Once this relatively simple skill
was mastered, it mattered little where one
purchases parts. We're now free to concentrate
on the weakest links the OBAM aircraft fabrication
chain . . . knowledge, resources and skill set
of the builder. This is one area where process
trumps science every day.
Again, thanks for the help on the journey and the
decision making that lies at every turn.
My pleasure sir . . .
Bob . . .
--
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________________________________________________________________________________
| Subject: | Re: Battery charging |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Hi Stan,
Actually I have always used the Odyssey 680 in my Europa. I trust
Pana in terms of general quality, but the specs for the Odyssey are better
for me in the Northeast.
Just changing batteries annually because you don't choose to learn about
batteries (Not talking about anyone individually here) is a shame. Money
is tight all around and frequent changes ignores the real possibility of
infantile failure which is just as likely in the real world as premature failure
if the products are made in the far, far east.
Sometimes experts disagree. This is Bob's group and I respect that.
I appreciate his public service in dealing with the underending series
of questions. There are also other opinions formed on reasonably
solid foundations of knowledge and experience that may differ
however because some experts place different priorities on different
aspects of a project. Look for example on the scrap between Nuckolls
and Richter a few years ago.
I was once an E.E., I spent 8 years in school and grad school, I
try to keep up with the literature and I hand built my plane and panel.
Ergo, I have opinions and they are not always the same as Bob's.
Is is certainly not a dis at Bob when I think there are better places to
spend money than changing out batteries that should be fairly fresh.
(Of course some people know when they have intentionally abused a battery - that
is a different story)
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289060#289060
________________________________________________________________________________
| From: | "Tom Barter" <kesleyelectric(at)iowatelecom.net> |
| Subject: | Loadmeter Shunt 10 amp |
Glenn,
I recently purchased a 10 amp shunt for my SD-8 load meter from B&C. It is
the open style, but should be OK behind the panel. That is where mine is
going.
Tom Barter
Kesley, IA
Avid Magnum
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
longg(at)pjm.com
Sent: Wednesday, March 03, 2010 8:48 AM
Subject: AeroElectric-List: Loadmeter Shunt 10 amp
Can you folks recommend (a link to) a loadmeter shunt for a 10 amp
application (SD-8)? I see B & C has from 20 and up. I tried digi-key but
that place is like sorting through my attic. I prefer the closed type so
I can use it inside my panel.
Thanks,
Glenn
________________________________________________________________________________
| From: | "Noah" <sgninc(at)cox.net> |
Two questions regarding Z-8.
1. I assume this "new" Z-8 is different from the Z-8 published in 1999 in your
document "All Electric Airplane on a Budget" at:
http://www.matronics.com/aeroelectric/articles/allelect.pdf
If this is the case, why not give the new Z-8 a new name to eliminate confusion?
2. What is the minimum practical battery capacity that would be recommended in
a system as described above, on the bus with the smaller alternator (SD-20 in
my case)? I am not asking from a battery-only loads & endurance standpoint, but
rather from a battery-as-an-alternator-reservoir/voltage-stabilizer standpoint.
I am loathe to install a second battery, contactor, and additional components when
I think my requirements are met without them, but I will certainly have a
long hard look at what is proposed and do some soul searching.
Part of my question stems from the fact that my 16 A-Hr battery is already pretty
much integrated into my platform.
--------
Highest Regards,
Noah Forden
RV-7A
Rhode Island
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289084#289084
________________________________________________________________________________
| From: | Gerald Giddens <pruemotorgliders(at)cox.net> |
On Mar 2, 2010, at 7:54 PM, Robert L. Nuckolls, III wrote:
> Might a switch be more efficient than a relay for the E bus load,
assuming a ~10
> amp load? (I'm not refering to the brown out relay which I see is
> necessary).
>
> Certainly more efficient since the switch does not
> draw current to keep it closed. But the relay is
> called for when it is functioning as a mini-contactor
> located adjacent to the battery bus. If you can reach
> a switch located there, then you could consider the
> subsitution.
>
> What do these little Bosch type cube relays draw?
> Thanks, Tim Andres
>
> About 100 mA depending on manufacturer and some
> other details. These are not big energy hogs.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | jerb <ulflyer(at)verizon.net> |
| Subject: | Re: This switch OK? |
John,
Reading your reply to other folks replies I am concerned of your
using this switch for your intended application.
First off, the switch information you provided in the attachment does
not designate if it is rated for AC or DC current. Note, an AC rated
switch if used in an DC current application, the DC current capacity
will normally be only a fraction of it's AC current rating. Second,
I would point out that the reply by Joe saying that you could
probably run 5 amps of current exceeds the switches current rating,
if it turns out to be an AC application switch, you would be further
outside the switches safe operating limits. Neither would be
acceptable solution.
I strongly recommend you determine your current needs for the circuit
your controlling. Then determine if the switch your considering is
AC or DC rated. If the switch is AC rated, find another switch
appropriate for your application. Do it right the first time, you
might not get the second chance to do it over again.
jerryb
>Attachments:
>
>http://forums.matronics.com//files/picture_1_380.png
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 02:10 PM 3/3/2010, you wrote:
>
>Two questions regarding Z-8.
>
>1. I assume this "new" Z-8 is different from the Z-8 published in
>1999 in your document "All Electric Airplane on a Budget" at:
>http://www.matronics.com/aeroelectric/articles/allelect.pdf
>If this is the case, why not give the new Z-8 a new name to
>eliminate confusion?
Many moons ago, the z-figures went from Z-1 to 10 and somewhere
around revision 8 or 9 were replaced with Z-11 and on as they
were redrawn to be more consistent with each other. The suite
of drawings was extended upward from Z-11. It was my plan
at some time to fill the lower numbers back in later. Z-8
was the predecessor to Z-13/8. It only appears in the 1999
article and very old issues of the 'Connection which should
have been updated several times over.
>2. What is the minimum practical battery capacity that would be
>recommended in a system as described above, on the bus with the
>smaller alternator (SD-20 in my case)? I am not asking from a
>battery-only loads & endurance standpoint, but rather from a
>battery-as-an-alternator-reservoir/voltage-stabilizer standpoint.
Technically, any size battery is adequate to the task
of tickling an alternator to life. Batteries are of little
value in noise abatement or voltage stabilization.
Further, the smaller they get, the more they suffer
the 'abuse' of short but heavy charge/discharge
events. Having offered that, I have no idea what would
be considered useful to your task. You'll need to put
some sort of preventative maintenance program on it
or (ugh!) throw a new one in ever so often. It may
be that a tiny (6 a.h. or less) battery wouldn't
support this application for a year . . . I just don't
know. You can just pick one, check it from time to
time and see how it goes. There some small products
by Dekka that feature robust terminals indicative
of an ability to source/sink the transients.
>I am loathe to install a second battery, contactor, and additional
>components when I think my requirements are met without them, but I
>will certainly have a long hard look at what is proposed and do some
>soul searching.
The answer lies not with the soul but with calculated
and considered assembly of ingredients into a recipe
for success that meets your design goals.
The task before you is the same that evolved the
Z-figures over the years. You can look forward
a sifting the details in search of the stable
configuration.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: This switch OK? |
>I want to use it for Coil Power for a GearedDrives LS1 V8 engine in
>an RV-10. I'm not sure what the Coil actually draws but the wire is
>protected by a 15 amp fuse. The wire from the engine looks like a 14
>or 16awg. I'll have to look into the actual draw, but this switch
>will probably not work since I need reliability. Thanks for the reply,
What coil? Ignition? The picture I saw appears to
be a momentary push button. If it has 3 terminals,
then I suspect it's a single-pole, double-throw
device. Further, push-buttons of this style are
slow-make, slow-break (no fast acting over-center
mechanism). VERY poor technology for switching
reactive DC loads.
Bob . . .
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Looking at the picture of this switch (made in UK), the first thing that came to
mind is that it was going to be used for a starter switch. It turns out that
John intends to use it for a more critical application where a high quality
switch should be used. So I take back what I said about the switch being ok to
use.
As a general rule, a 125VAC rated switch can handle the same current at 14VDC,
even if the manufacturer does not publish the DC rating. Every AC switch has
a DC ampacity. That ampacity might not have been determined by testing and
thus is unknown.
Jerry B. said,
> "the DC current capacity will normally be only a fraction of it's AC current
rating."
That is true if the voltage remains the same: 250V in this case. But, generally speaking, a 125VAC rated switch can carry as much DC current at 14V as it can carry AC current at 125V. An example of this can be seen by reading the data sheet for another switch. http://www.nkkswitches.com/pdf/stoggleslowcap.pdf
Notice that 125VAC rating is identical to the 30VDC rating. At 14VDC, this switch
can handle even more. Also notice that this switch can handle 2 1/2 times
the current at 30VDC than it can at 250VAC. Most good quality snap action AC
switches are suitable for use in homebuilt aircraft as long as the 14VDC current
does not exceed the 125VAC rating of the switch.
Comments are welcome.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289145#289145
________________________________________________________________________________
| From: | "B Tomm" <fvalarm(at)rapidnet.net> |
| Subject: | Re: This switch OK? |
Remember...
Switches manufactured in the UK will not work in any north American aircraft
(certified or amateur built) as the current flow requirement is OPPOSITE to
what we consider normal. This is why many switch configurations in the UK
call for switch orientation to be up to be OFF and down to be ON. :)
Just trying to help. We're all in this together. Keep yur sticks on the
ice.
Bevan :)
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of user9253
Sent: Wednesday, March 03, 2010 6:21 PM
Subject: AeroElectric-List: Re: This switch OK?
-->
Looking at the picture of this switch (made in UK), the first thing that
came to mind is that it was going to be used for a starter switch. It turns
out that John intends to use it for a more critical application where a high
quality switch should be used. So I take back what I said about the switch
being ok to use.
As a general rule, a 125VAC rated switch can handle the same current at
14VDC, even if the manufacturer does not publish the DC rating. Every AC
switch has a DC ampacity. That ampacity might not have been determined by
testing and thus is unknown.
Jerry B. said,
> "the DC current capacity will normally be only a fraction of it's AC
current rating."
That is true if the voltage remains the same: 250V in this case. But,
generally speaking, a 125VAC rated switch can carry as much DC current at
14V as it can carry AC current at 125V. An example of this can be seen by
reading the data sheet for another switch.
http://www.nkkswitches.com/pdf/stoggleslowcap.pdf
Notice that 125VAC rating is identical to the 30VDC rating. At 14VDC, this
switch can handle even more. Also notice that this switch can handle 2 1/2
times the current at 30VDC than it can at 250VAC. Most good quality snap
action AC switches are suitable for use in homebuilt aircraft as long as the
14VDC current does not exceed the 125VAC rating of the switch.
Comments are welcome.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289145#289145
________________________________________________________________________________
| From: | Sam Hoskins <sam.hoskins(at)gmail.com> |
I am getting a lot of strobe noise in my headset and was hoping we could
work through this. It is so bad that I cannot fly with the strobes on. Here
are the basics:
Aircraft: all composite Quickie Q-200 <http://www.samhoskins.blogspot.com/>
SkyBrite strobes/position lights http://www.airplanegear.com/skybright.htm
Wing tip lights. Power supply is mounted on the right fuselage wall, right
bebeath the rear wing.
Radio: ICOM A210
http://icomamerica.com/en/products/avionics/panelmount/a210/default.aspx
Antenna: Bob Archer com antenna model SA-006, mounted on left side of
fuselage, just aft of the rear wing.
http://www.chiefaircraft.com/airsec/Aircraft/Antennas/ArcherSportcraft.html
The distance between the power supply and the antenna is perhaps four feet.
The Skybrite installation instructions call for using "*Strobe Extension
Cables (light-duty, 3-conductor, 18 gauge, shielded)" *made from that heavy
PVC stuff. I could not route this cable through the confines of my wing, so
I used smaller diameter 3 conductor, shielded, 20 gauge, Tefzel wire.
Symptom: When the strobes are on, there is an overall kind of a white noise
background and the shoowp-swoowp kind of pulsing noise of the strobes. I
can't make it go away with the squelch control, even jacked all the way up.
On Bob's suggestion, I removed the strobe PS input and supplied the 12V with
a battery positioned right next to the PS. It seemed to help a tiny bit,
but still no joy.
Any more suggestions? Nothing is easy to do on this plane, and everything
is hard to get at. I cannot fit a vertical antenna in the tail, since it is
already built.
Thanks,
Sam
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe noise |
At 06:14 AM 3/4/2010, you wrote:
>I am getting a lot of strobe noise in my headset and was hoping we
>could work through this. It is so bad that I cannot fly with the
>strobes on. Here are the basics:
>
>Aircraft: all composite <http://www.samhoskins.blogspot.com/>Quickie Q-200
>
>SkyBrite strobes/position lights
><http://www.airplanegear.com/skybright.htm>http://www.airplanegear.com/skybright.htm
>Wing tip lights. Power supply is mounted on the right fuselage
>wall, right bebeath the rear wing.
>
>Radio: ICOM A210
><http://icomamerica.com/en/products/avionics/panelmount/a210/default.aspx>http://icomamerica.com/en/products/avionics/panelmount/a210/default.aspx
>
>Antenna: Bob Archer com antenna model SA-006, mounted on left side
>of fuselage, just aft of the rear wing.
><http://www.chiefaircraft.com/airsec/Aircraft/Antennas/ArcherSportcraft.html>http://www.chiefaircraft.com/airsec/Aircraft/Antennas/ArcherSportcraft.html
>
>The distance between the power supply and the antenna is perhaps four feet.
>
>The Skybrite installation instructions call for using "Strobe
>Extension Cables (light-duty, 3-conductor, 18 gauge, shielded)" made
>from that heavy PVC stuff. I could not route this cable through the
>confines of my wing, so I used smaller diameter 3 conductor,
>shielded, 20 gauge, Tefzel wire.
>
>Symptom: When the strobes are on, there is an overall kind of a
>white noise background and the shoowp-swoowp kind of pulsing noise
>of the strobes. I can't make it go away with the squelch control,
>even jacked all the way up.
>
>On Bob's suggestion, I removed the strobe PS input and supplied the
>12V with a battery positioned right next to the PS. It seemed to
>help a tiny bit, but still no joy.
Do you have an audio system of any kind? Intercom?
Does radio volume control knob affect what noise
you hear? Do you hear the noise with the antenna
disconnected from the back of the radio? Do you
hear the noise on a hand-held radio while seated
in the cockpit (tune to unused frequency an open
the squelch)?
Bob . . .
>Any more suggestions? Nothing is easy to do on this plane, and
>everything is hard to get at. I cannot fit a vertical antenna in
>the tail, since it is already built.
>
>Thanks,
>
>Sam
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "johngoodman" <johngoodman(at)earthlink.net> |
I'd like to thank everybody for the interest - I've learned a lot about switches
(g).
I've moved on from that switch to possibly this one, but I still need to find out
the actual amps on the Coil first:
Included:
1 x Clear Illuminated Button
1 x Protector Cover
1 x Label Sheet (Water Spray, Wipers, Lights, Nitrous, Fan, etc.)
Specifications:
Switch Acutation Style: Push Button
Circuit Activation: Constant
Lighted: Yes (White)
Amp Rating: 10A
Volt Rating: 30VDC
Terminal Type: Blade
Material: Plastic
Quantity: Sold Individually
Mounting Size: 16mm or 5/8"
John
--------
#40572 QB. Engine on, wing attach coming soon. Panel delivery soon.
N711JG reserved
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289193#289193
Attachments:
http://forums.matronics.com//files/ign_6000_c_288.jpg
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: This switch OK? |
At 08:46 AM 3/4/2010, you wrote:
>
>
>I'd like to thank everybody for the interest - I've learned a lot
>about switches (g).
>I've moved on from that switch to possibly this one, but I still
>need to find out the actual amps on the Coil first:
It would sure help if we understood exactly what
this switch is supposed to do. Do you need
push-on, push-off (alternate action) or simply
push-on (momentary but spring loaded to off).
Exactly how does the switch under study integrate
into your airplane . . . and is there a reason
it shouldn't be but one of several switches that
accomplish different tasks? Like one of a row
of switches that control DC power, landing lights,
nav lights, etc.
In other words, why this decidedly odd
device in a machine that will undoubtedly have
several other switches?
Bob . . .
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "johngoodman" <johngoodman(at)earthlink.net> |
> It would sure help if we understood exactly what
> this switch is supposed to do. Do you need
> push-on, push-off (alternate action) or simply
> push-on (momentary but spring loaded to off).
>
> Exactly how does the switch under study integrate
> into your airplane . . . and is there a reason
> it shouldn't be but one of several switches that
> accomplish different tasks? Like one of a row
> of switches that control DC power, landing lights,
> nav lights, etc.
>
> In other words, why this decidedly odd
> device in a machine that will undoubtedly have
> several other switches?
>
> Bob . . .
I guess some explanation is in order, sorry about that. I'm looking for a unique
switch for Coil Power for my GearedDrives LS1 engine. The panel has a VP200
and no other switches except two battery switches that look just like the VP200
switches (autopilot does have a couple of micros).
The reason for a Coil switch is that I need a quick way to kill the engine. There
is no key, and the VP takes care of starting. Otherwise I would have to remove
power from the battery busses to stop the engine at the end of the flight.
This would kill everything at once, unless I did some power isolation first.
So, I'm looking for a Latching Pushbutton, preferably lit when on. It needs to
be obvious to the passengers that it powers the engine. In reality, I think it
only draws about 3 amps, 5 at most. Think of it as the "run" position of your
keyed ignition.
Hope this helps.
John
--------
#40572 QB. Engine on, wing attach coming soon. Panel delivery soon.
N711JG reserved
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289217#289217
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: This switch OK? |
>
>I guess some explanation is in order, sorry about that. I'm looking
>for a unique switch for Coil Power for my GearedDrives LS1 engine.
>The panel has a VP200 and no other switches except two battery
>switches that look just like the VP200 switches (autopilot does have
>a couple of micros).
>The reason for a Coil switch is that I need a quick way to kill the
>engine. There is no key, and the VP takes care of starting.
>Otherwise I would have to remove power from the battery busses to
>stop the engine at the end of the flight. This would kill everything
>at once, unless I did some power isolation first.
>So, I'm looking for a Latching Pushbutton, preferably lit when on.
>It needs to be obvious to the passengers that it powers the engine.
>In reality, I think it only draws about 3 amps, 5 at most. Think of
>it as the "run" position of your keyed
>ignition.
What do your other switches look like? Are
they all the same kind of switch? Are there
other switches that go to control of engine
accessories? Fuel pumps? Why not an identical
switch that says "IGNITION ON" when up and
"OFF" when down?
The device you're considering has a much more
complex internal mechanism than the plain-vanilla
toggle switch. You speak to "removing power from the
battery busses to stop the engine". What devices
feed from battery busses and how are they controlled
to disconnect while the airplane is parked? Is any
single feed from the battery bus required for
the engine to function . . . does that feed power
a device has a backup? You speak to "busses" . . .
so I presume you have dual batteries with 1/2 of
engine-critical loads powered from each battery . . .
how is the change-over from "primary" to "secondary"
hardware accomplished?
Bob . . .
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "user9253" <fran4sew(at)banyanol.com> |
John,
If this switch is going to kill the engine, what will happen if the switch fails
while flying? Assuming that you have two ignition systems, there should be
one switch for each. Is that what you have planned?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289236#289236
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: This switch OK? |
John
If like many of us here you looking for more than just a yes or no
answer, you might consider that most of us running EFI
systems do not cut ignition power to kill the engine. (I'm assuming you
have EFI) That leaves fuel in the cylinders and (same as a Lycoming) can
be a safety hazard if someone moves the prop on a hot engine. Most EFI
computers will kill the fuel before the ignition.
The next preferred shutdown method would likely be to kill power to the
electric fuel pump(s). That is what I do when I taxi in on my backup EFI
system. Anything other than a normal system shutdown can set engine
codes on some computers though.
I do control power to my secondary ignition coils through a toggle
switch but I never shutdown the engine that way.
Ken
johngoodman wrote:
>
>
>
>
> I guess some explanation is in order, sorry about that. I'm looking
> for a unique switch for Coil Power for my GearedDrives LS1 engine.
> The panel has a VP200 and no other switches except two battery
> switches that look just like the VP200 switches (autopilot does have
> a couple of micros). The reason for a Coil switch is that I need a
> quick way to kill the engine. There is no key, and the VP takes care
> of starting. Otherwise I would have to remove power from the battery
> busses to stop the engine at the end of the flight. This would kill
> everything at once, unless I did some power isolation first. So, I'm
> looking for a Latching Pushbutton, preferably lit when on. It needs
> to be obvious to the passengers that it powers the engine. In
> reality, I think it only draws about 3 amps, 5 at most. Think of it
> as the "run" position of your keyed ignition. Hope this helps. John
>
> -------- #40572 QB. Engine on, wing attach coming soon. Panel
> delivery soon. N711JG reserved
>
>
________________________________________________________________________________
| From: | jerb <ulflyer(at)verizon.net> |
| Subject: | Re: This switch OK? |
Whoa there Joe,
Wow! Can't believe your saying using use AC rated switches for DC
applications at near the full AC current rating is OK. No way.
AC switches take advantage of the AC zero crossing for reducing
contact arcing and welding. (The reason DC switches amp for amp
typically cost more than AC switches, there made different to reduce
and eliminate contact arcing and welding.) And suddenly you say
using the switch the gentlemen asked about is OK and justify your
recommendation upon the spec's of a totally different switch. Use
the right type of switch for your application. Maybe you can
convince the folks that select the switches used for DC powered
landing gear applications to use AC designated switches. Just don't
think you'll quite sell them on your method.
jerb
At 06:21 PM 3/3/2010, you wrote:
>
>Looking at the picture of this switch (made in UK), the first thing
>that came to mind is that it was going to be used for a starter
>switch. It turns out that John intends to use it for a more
>critical application where a high quality switch should be used. So
>I take back what I said about the switch being ok to use.
> As a general rule, a 125VAC rated switch can handle the same
> current at 14VDC, even if the manufacturer does not publish the DC
> rating. Every AC switch has a DC ampacity. That ampacity might
> not have been determined by testing and thus is unknown.
> Jerry B. said,
> > "the DC current capacity will normally be only a fraction of it's
> AC current rating."
> That is true if the voltage remains the same: 250V in this
> case. But, generally speaking, a 125VAC rated switch can carry as
> much DC current at 14V as it can carry AC current at 125V. An
> example of this can be seen by reading the data sheet for another
> switch. http://www.nkkswitches.com/pdf/stoggleslowcap.pdf
>Notice that 125VAC rating is identical to the 30VDC rating. At
>14VDC, this switch can handle even more. Also notice that this
>switch can handle 2 1/2 times the current at 30VDC than it can at
>250VAC. Most good quality snap action AC switches are suitable for
>use in homebuilt aircraft as long as the 14VDC current does not
>exceed the 125VAC rating of the switch.
>Comments are welcome.
>Joe
>
>--------
>Joe Gores
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "johngoodman" <johngoodman(at)earthlink.net> |
Sorry that I've got everybody wondering; I'll try to explain.
The GearedDrives LS1 Corvette engine is just like a car. In a traditional car,
the key has several positions, the last rotation is "start", and it is spring
loaded to come out of start to "run." The "run" position is Coil power. It is
not actual Coil power which is a lot of juice, just a relay out "under the hood."
When you turn off a car, you don't starve it of fuel like airplanes normally
do, you kill the coil power.
As far as my switches, The VP200 does everything with soft switches and it's switch
panel. The Master Battery and Aux Battery switches are positioned next to
the switch panel and are the same brand of switches. The two fuel pumps and the
Engine Crosstie will be on three guarded switches on the console, under the
panel, that will be normally on. See Z-19 but add a crosstie between the two
batteries, put the engine battery bus on the "on" side, but leave the Keep Alive
power for the ECU on the engine battery hot side.
There shouldn't be fuel in the cylinders because the ECU won't inject any and the
fuel rail regulator is closed. The prop is not connected to the engine because
the clutch has released around 700 rpm. You can spin the prop all you want.
Fuel is still pumping but isn't getting past the Filter/Regulator which returns
all the fuel to the tanks. Fuel can be stopped by turning off the batteries
or opening the guarded pump switches.
I'm sure a lot of you think this is wrong, but I'm really not asking. I'm only
trying to find a good Kill Switch that is so obvious that even a Cave Man Can
Do It.
I'm still amazed that a guy steered a stuck pedal Toyota for 6 miles without ever
thinking about the shift stick or the key....
John
--------
#40572 QB. Engine on, wing attach coming soon. Panel delivery soon.
N711JG reserved
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289283#289283
________________________________________________________________________________
| Subject: | Re: This switch OK? |
| From: | "user9253" <fran4sew(at)banyanol.com> |
> Wow! Can't believe your saying using use AC rated switches for DC applications
at near the full AC current rating is OK. No way.
JERB,
I am not the only one who thinks that it is OK to use AC rated switches in airplanes.
Read the last paragraph on Page 2 and page 3 of this document written
by a well respected electrical guru,
http://www.aeroelectric.com/articles/Switch_Ratings.pdf
Here is a quote from that article:"
> In a nutshell, 125 VAC ratings equate favorably and conservatively to 14 VDC
ratings - as long as the switch has a healthy "snap" action . . .The switches
we stock sell for $5.00 in a single-pole device and carry no markings for DC ratings.
They are rated at 7 amps or better at 115 AC and will work just fine
in virtually every slot on an airplane panel."
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289291#289291
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: This switch OK? |
At 10:36 PM 3/4/2010, you wrote:
>
>
> > Wow! Can't believe your saying using use AC rated switches for DC
> applications at near the full AC current rating is OK. No way.
All switches have ac and dc capabilities at some level.
Just because the ratings on the printed on the side of
the switch are given at 120 or 240 VAC simply speaks
to the largest market into which they are sold. It
doesn't mean that they don't have useful and quite
rational application in DC systems. The comparative
ratings charts for switches in any well written
switch catalog will confirm this assertion.
The voltage rating of a switch is driven mostly by
it's ability to break a circuit . . . spread the
contacts fast enough so that the fire goes out
before damage is done. The intensity of that fire
is proportional to the current in the circuit at
the time the contacts open.
So a switch with contacts that don't overheat at
7A will CARRY that much current at any voltage but
the current may have to be de-rated at the higher
DC voltages . . . because it's harder to put the
BREAK the circuit without generating a lot of heat.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Z8 scrapped . . . |
I've been wrestling with the design goals for
tying two alternators to their own dedicated
battery busses and then tying one or both
to a main bus.
Alternators using B&C alternator controllers
are not suited to this idea at all. They're
marginally okay if one of the alternators is
the SD-20 with an SB-1 regulator set to "relax"
the SD-20 when the main alternator is functional
(al la Z-12). But managing the input terminals
to the alternator controllers from an always
hot battery bus adds more poles to a DC
MASTER switch or adds complexity to the system
when handled with multiple switches . . . with
an attendant risk of mis-positioned switches
causing mis-behaviors.
There's also the issue of compliance with the
legacy "switches-off, max-cold" philosophy
for fat wires. The design demands either
b-lead disconnect contactors or fat diodes
on heat sinks.
The design looks better with internally regulated
alternators because they don't have the LV warning
systems and they do regulated voltage sensing
internally at the b-lead. But this demands b-lead
contactors as opposed to b-lead diodes because
the voltage drop across the diode cannot be
compensated for by sensing bus volts downstream
of the diode. So one COULD do some Z24-like
implementations of two alternators driving
dedicated batteries . . . but we still have
paralleling issues and increased pilot workload
to properly position switches.
The system was looking like we needed 5 contactors
total. 2 battery, 2 b-lead, 1 starter.
Finally, with the Z-8 dual-battery/dual-alternator
configuration, you can't have both alternators
driving the main bus at the same time . . . because
of load sharing issues. So this means that while
you can have both alternators running to support
their respective flying loads, only one can be
connected to the main bus at a time.
If one wants two, capable alternators and two
batteries, then Z-14 is still the architecture
of choice offering totally independent systems
with cross-tie capabilities. Z-13/8 is still the
elegant choice for low-cost, light-weight,
simple-operation.
This has been a useful exercise in that it validates
the work already published and illuminated the
messiness of what was initially perceived as another
recipe for success.
My recommendations for optimizing Noah's adaptation
of an SD-20 into his project is replace the SB-1
regulator with a generic "ford" style regulator,
add a b-lead contactor to implement fat-wire
disconnection when parked. Take field power/
voltage sensing directly from the battery bus
through a fusible link then to 5A breaker, crowbar
ovm and then to contactor+regulator bus
connection. Placard the system against
simultaneous operation of both alternators.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Z8 scrapped . . . |
My recommendations for optimizing Noah's adaptation
of an SD-20 into his project is replace the SB-1
regulator with a generic "ford" style regulator,
add a b-lead contactor to implement fat-wire
disconnection when parked. Take field power/
voltage sensing directly from the battery bus
through a fusible link then to 5A breaker, crowbar
ovm and then to contactor+regulator bus
connection. Placard the system against
simultaneous operation of both alternators.
ALTERNATIVELY
Consider going to Z-14. Use aux battery consistent
with experimentation to deduce smallest
satisfactory performance. Set the SB-1
up to 14.4 volts.
Bob . . .
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Help with an BMA EFIS/One question |
I have a BMA EFIS/One G3 gold box. My plane is to the point where I have started
checking out the avionics interconnections. I have the EFIS connected to my
SL30 and to my Trutrak autopilot. The
Trutrak was not communicating so I opened the EFIS/One up to take a look. I discovered
that the additional serial ports, one of which is connected to the Trutrak
and which I assumed were a standard
part of the EFIS/One, are not there. Contacting "alumni" from BMA indicates that
the serial ports were an option - which I didn't request since I didn't know
they were optional.
In any case, the ports were on a standard PC104 quad serial port board which I
could easily add to my system if I only knew what board it was and what settings
on the board.
So far no one with any involvement with BMA has been able to help me identify the
board.
So my questions are:
Is there any one who has an EFIS/One G3 with the serial port option that could
open their box and either take a picture of each side of the top (approx 3.5"x3.5")
board or let me know of any
manufacturing numbers on the board?
Or, is there anyone with this EFIS that has the serial ports, is not using the
extra serial ports (ports 2-5) and would be interested in selling me the serial
port board? Or, if the price is right,
the entire G3.
And for those of you who are not aware, there is someone on the BMA forums that
is currently working to get regular chart updates going again (with Greg's blessing).
The plan is for them to be even
cheaper than when BMA was supplying them since the charts will be generated directly
from the feds database, rather than through Jeppeson as a middleman. Not
that the difference in cost is really a
big deal if charts are available again!
Thanks for any help you can offer.
Dick Tasker
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
> What Z wiring diagram fits this engine?
Z-19 is a best fit for electrically dependent engines
with only one alternator.
>
>The chapter on batteries suggests an Odyssey PC680 battery. In
>doing research on this battery, it seems to be indicated for a
>motorcycle engine. Would it provide enough cranking power?
The 680 is PLENTY . . . but you may want to consider
two batteries for alternator-out operations. One for
the engine, one for everything else.
Do you have a load analysis? I.e. a listing of all
electrical accessories and what their current demands
are for normal operations?
>
>In reading, many times it suggested that grounding the engine should
>be done through the engine pan. Is there a reason why the engine
>pan is used VS gounding directly to the engine block?
Don't know why anyone would do that. The most substantial
bolt to the block that is not TORQUE sensitive is the
best place to get a robust electrical connection to
the engine.
>The Zenith 801 is a bush plane. My goal in finishing the plane is
>to keep it as light as possible. Over the last several months I
>have "listened" in on the discussion of fuses vs breakers and
>whether a transponder is needed.
Breakers vs. fuses are a rather small weight trade off.
Especially if your failure mode effects analysis suggests
that two batteries are called for. Transponders are only
useful if somebody on the ground (1) can even see you
on radar and (2) give a rat's you know what where you
are.
>Basically, I believe what a person really needs is a list of parts
>needed to wire a panel and where they can be purchased. There were
>good suggestions on fuse blocks and cup holders, but many things are
>missing. I guess it first begins with which Z diagram I need to use
>and then, I can go from there.
First you need to quantify the total energy budget
for (1) normal operations and then (2) an austere budget
for alternator out operations. Finally, decide what your
personal design goals are for alternator out endurance.
If you've got big fuel tanks then perhaps your batteries
need to be commensurately big too.
>I have studied Spanish for thirty years, and can do well. However,
>if we had a discussion on auto parts in Spanish, I would be
>lost. In reading your discussions on many issues, I feel like the
>kid who can tell you, "Where is the bathroom" in spanish, but is
>lost when asked to say more. As a read more and more, I catch a
>little more. However, there is a large void to fill.
That's what we're here for. Let's discover whether
a D8 Cat is needed . . . or you can shovel enough electrons
around with a garden tractor. Also, how many yards
of dirt do you need to move? This energy management
thing is a function of TIME, LOADS and under what
conditions those loads must be functioning for you
go get on the ground comfortably with a dead alternator.
If you're flying day-vfr kinds of missions perhaps
your energy requirements are modest . . . won't know
until you list them and add 'em all up.
Finding all the bits and pieces to wire it up is
the stone simple part.
Bob . . .
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | Solid State Contactors -- SuperSwitch? |
Hello,
Has anyone had experience with the solid state contactors from Lamar
Technologies they call a SuperSwitch? See this Aircraft Spruce link for
info:
http://www.aircraftspruce.com/catalog/elpages/superSwitch.php
I know they're expensive - but, we're already in that category of contactor
with the need for 28V high continuous current contactors (100 A alternator,
all electric A/C). We already have very nice Blue Sea high capacity
contactors that are hermetically sealed (~$150 each). They weigh about a
pound each, though, and the significant weight savings with these solid
state contactors looks good.
I'd appreciate comments and advice.
Thanks,
Valin Thorn
Legacy
Houston, TX USA
cid:image001.jpg(at)01CAB316.6FD47F10
cid:image002.png(at)01CAB316.6FD47F10
Exerpt of info on web link:
Features
* Up to 66% lighter weight
* 99% more reliable
* 5 to 44 volt operating range
* Replaces all mechanical contactors
* Solid state technology
* No moving parts
* Up to 600 amps momentary operation
* Up to 100 amps continuous
* Negative or positive turn on
Specifications
* Input: Input control current 5 to 44 volts
* Output: Operating DC voltage range 0 to 44 volts
* Maximum continuous current 100 amps
* Maximum surge current (IDM) - .1mS: 1200
* Ambient operating temperature range: -40 C to 85 C
* Weight: Uni-directional .3 lbs
* Bi-directional .5 lbs
* Encapsulation: Potting or conformal coating
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Solid State Contactors -- SuperSwitch? |
At 03:04 PM 3/6/2010, you wrote:
>Hello,
>
>Has anyone had experience with the solid state
>contactors from Lamar Technologies they call a
>SuperSwitch? See this Aircraft Spruce link for info:
>
><http://www.aircraftspruce.com/catalog/elpages/superSwitch.php>http://www.a
ircraftspruce.com/catalog/elpages/superSwitch.php
>
>I know they=92re expensive ' but, we=92re already in
>that category of contactor with the need for 28V
>high continuous current contactors (100 A
>alternator, all electric A/C). We already have
>very nice Blue Sea high capacity contactors that
>are hermetically sealed (~$150 each). They
>weigh about a pound each, though, and the
>significant weight savings with these solid state contactors looks good.
>
>I=92d appreciate comments and advice.
This same question came up a few years ago
http://www.matronics.com/forums/viewtopic.php?t=26571
I'd not heard of them at that time. I did write to Lamar
asking for an engineering data package that would help
me evaluate the potential for incorporation onto TC
aircraft. As I recall, I got an answer from somebody
in sales who promised to forward my request to the
right individual.
Never heard back and I guess it slipped my mind.
I just did an advanced search on "superswitch"
limited to http://www.lamartech.com/ and the
search engines did not return a hit. Did anohter
search on "07-01283" and "lamar". Got hits on
Aircraft Spruce and Skyshop in Australia.
Searched the whole constellation of matronics forums
and got two hits . . . THIS thread and the one I
cited above from some years ago. So I guess
the short answer is, haven't got a clue as to
how good the product is (although Lamar is
usually a low risk choice for other things).
It doesn't appear that they've made much of
a splash in the marketplace.
Bob . . .
________________________________________________________________________________
| From: | "Steve Hamer" <s.hamer(at)verizon.net> |
| Subject: | Voltage gauge question |
I have an Electronics International Volts/Amp gauge in my RV-6. It was
working fine till I decided to "fix" what I thought was too small of
wire through the E-Buss switch circuit. I'm wired per figure Z-11 and
the Voltage gauge is powered off of the E-Buss.
Here's what's happening. With the master on, the voltage reads 11.4
(through the diode). When I turn on the E-Buss switch, voltage goes to
12.1. With just the E-Buss on and the master off, voltage reads zero.
It didn't do this before I "fixed" it. What have I done?
Thanks,
Steve Hamer
________________________________________________________________________________
| From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
| Subject: | Voltage gauge question |
I have an Electronics International Volts/Amp gauge in my RV-6. It was
working fine till I decided to "fix" what I thought was too small of wire
through the E-Buss switch circuit. I'm wired per figure Z-11 and the
Voltage gauge is powered off of the E-Buss.
Here's what's happening. With the master on, the voltage reads 11.4
(through the diode). When I turn on the E-Buss switch, voltage goes to
12.1. With just the E-Buss on and the master off, voltage reads zero. It
didn't do this before I "fixed" it. What have I done?
Steve Hamer
What did it do before you fixed it?
Roger
________________________________________________________________________________
| From: | "Steve Hamer" <s.hamer(at)verizon.net> |
| Subject: | Re: Voltage gauge question |
Before I fixed it, with the E-Buss on and the master off, the voltage
was around 11.7. This seemed too low so I figured the wire in that
circuit might be too small so I increased it slightly. That's the only
change. If I put my multimeter on the the voltage meter connection with
the E-buss only on, it reads 12.3 while the gauge reads 0.
Steve
What did it do before you fixed it? Roger
________________________________________________________________________________
| Subject: | Re: Solid State Contactors -- SuperSwitch? |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Solid state contactors might have a small leakage current when they are off.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289477#289477
________________________________________________________________________________
| Subject: | Re: Voltage gauge question |
| From: | "user9253" <fran4sew(at)banyanol.com> |
The vast majority of electrical problems are bad connections, so check those.
Pull on wires to make sure they are not broken.
The symptoms point towards a bad voltmeter (or its connections). Connect your
hand held meter to the exact same two points that the panel meter is connected
to, both hot and ground. If they do not read approximately the same, then
one of them is lying.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289485#289485
________________________________________________________________________________
| Subject: | Wide angle LED indicators |
| From: | "rparigoris" <rparigor(at)suffolk.lib.ny.us> |
Because of building model electric planes that we primarily fly at night, we have
collected quite the assortment of LEDs. Whenever we see something interesting,
usual end up getting a few samples to fool with. collection is from the big
4 > Mouser, Digikey, Allied and Newark as well as Best Hong Kong, Hosfelt and
others.
Now that it's time to install indicators and warning LEDs on Europa XS we quickly
came to realization that unless a warning indicator is in your direct line
of vision, it ain't gonna get your attention too quickly during when operated
in direct sunlight. we are going to use some nice black bezeled indicators for
non-critical indicators. Pepboys and Advace Auto are going to be suppliers for
wide angled warning LEDs! you see we want several warning LEDs by knees. For
three pretty important LEDs, Rotax 914 TCU Red and Orange and Oil pressure going
to use a cluster of 4 LEDs from Advanced. These are super bright and the cluster
of 4 is mounted on a small circuit board. By drilling a cluster of 4 holes
and allowing tips stick out a bit, the tips glow plenty bright, available
in Red, and Yellow at least. The neat thing is there is no flange on side of LEDs.
For other warning LEDs, Pepboys sell single LEDs that are ultrabright. Same
thing, no flange on sides and long enough to allow tip to stick out of panel,
small OD, available in red, Yellow and probably blue at least. Both Pepboys
and Advanced sell a neat wide angle LED where the face has a counterbore, may
be 5/16" or 3/8" OD (I forget) but very wide angle viewing but only available
in Blue, White and Yellow/Orange, no Red.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Hyper-Bright-Amber-LED-Automotive-Bulb-Pair-Jam-Strait_6120511-P_N3157A_A%7CGRP2044____
I got a pack of 3 from Pepboys but these are probably similar (didn't see these
in Advance and Pepboys website is poor at best):
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_HyperLED-Red-Alpena_6120501-P_N3157A_A%7CGRP2044____
you can get these in Yellow/Orange and Blue, I didn't see in Red:
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_194-WHITE-LED-BULBS-Pilot_6460030-P_N3157A_A%7CGRP2044____
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289549#289549
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Solid State Contactors -- SuperSwitch? |
Haven't used these, but they look identical to Teledyne's. $$ to donuts
that the manufacturer is the same.
http://www.futurlec.com/RelSS.shtml
________________________________________________________________________________
| From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
| Subject: | Solid State Contactors -- SuperSwitch? |
Haven't used these, but they look identical to Teledyne's. $$ to donuts that
the manufacturer is the same.
http://www.futurlec.com/RelSS.shtml
If you are planning on using one of these devices in your airplane, make
sure you purchase the ones for a DC load. Some of the ones for AC load,
require a zero crossing to switch and will not work for DC.
Roger
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Solid State Contactors -- SuperSwitch? |
>
>
>If you are planning on using one of these devices in your airplane,
>make sure you purchase the ones for a DC load. Some of the ones for
>AC load, require a zero crossing to switch and will not work for DC.
The device being discussed is offered by an aviation
equipment specialty house as a replacement for contactors
(where bi-directional current flow is needed) and another
version (relay) where uni-directional current flow will
suffice. They are expected to function in a DC power system.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Z8 scrapped . . . |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
nuckolls.bob(at)aeroelect wrote:
>
> ... SNIP
> My recommendations for optimizing Noah's adaptation
> of an SD-20 into his project is replace the SB-1
> regulator with a generic "ford" style regulator,
> add a b-lead contactor to implement fat-wire
> disconnection when parked. Take field power/
> voltage sensing directly from the battery bus
> through a fusible link then to 5A breaker, crowbar
> ovm and then to contactor+regulator bus
> connection. Placard the system against
> simultaneous operation of both alternators.
>
> Bob . . .
Bob, previously I stated my desire to use a standby 30a ER alternator in place
of the SD 8 in Z-13/8. I've been lurking as others, like Noah, pushed the thread.
I have a B&C LR-3 for the main alt and intended to use another one for the standby.
I have a mechanical "either, or" lockout device for the two alternator field
switches. As long as the two systems are mutually exclusive, am I correct
to understand that the prohibition re dual LR-3's, mentioned at the beginning
of your post, no longer applys? And that the suggested mods in the quote above
for Noah's system would not apply to Z-13/8 as I intend to modify it?
Thanks,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289592#289592
________________________________________________________________________________
| From: | "Lapsley R. and Sandra E. Caldwell" <lrsecaldwell(at)earthlink.net> |
| Subject: | Noise in Handheld Tx signal |
As is frequently the case, once you truly identify the root cause of a problem
the solution is obvious.
In this case we were using an external headset with the A24 hand held without an
external PTT. In other words we were using the hand held Tx button for the
PTT. The owners manual did not say if the external PTT was either recommend or
necessary with an external headset.
After discussing the problem with ICOM tech support they told me that when you
press the hand held TX button it connects the internal mic as well as the external
mic to the transmitted carrier. Consequently when we tried to transmit without
the engine running the Tx signal was reasonably quite but with the engine
running the mic in the hand held picked up the cockpit noise and transmitted
it along with the voice from the headset mic.
Correction of this problem was easy we just used an external PTT. Just one more
wire in the cockpit
I suspect that this may be common to other handhelds.
Roger
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Subject: Re: AeroElectric-List: Noise in Handheld Tx signal.
At 06:51 PM 2/28/2010, you wrote:
> >Caldwell"
> >
> >We have a problem with excessive noise occurring in an ICOM A24.
> >Receive is good. The noise only occurs in the transmitted signal
> >while the engine is running, The noise is so bad the the voice is
> >not understandable. If the operator is about 100 ft from the A/B
> >with the engine running the noise is down to a level that is acceptable.
>
> >Th hsndheld is completely independent of the a/c. Internal
> >batteries and operation on the rubber duckie antenna. A headset is
> >used. Two different A24's with different headsets exhibit the same problem.
> >
> >There are no avionics in the plane except for the handheld. To
> >eliminate the possibility of interference from instruments or
> >alternator we tested with the master off and the problem still exists.
>
Then it's not electrical noise. Sounds more like acoustic
noise coming in through the microphone(s).
> >Previously the A24 was used acceptably with an open cockpit biplane,
> >a Murphy Renegade.
> >
> >One possibility could be excessive gain using the external mike, but
> >I am skeptical since it was acceptable in the biplane
> >
> >Any suggestions?
>
You need to identify the nature of the noise. Props sound
different that exhausts which sound different than
ignition, strobes, EL panel inverters, etc.
If you key the hand-held with the external headset
disconnected and a tape over the built in microphone,
is it quiet then?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Z8 scrapped . . . |
John,
I'm vaguely interested. What is it you are running that requires 30 amps
of power running as a backup? Is that air-conditioning? If you're
essential + engine bus pulls 30 amps, you've got big dependencies. This
is a backup up right, ala emergency power source?
Glenn E. Long
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
jonlaury
Sent: Sunday, March 07, 2010 10:27 PM
Subject: AeroElectric-List: Re: Z8 scrapped . . .
nuckolls.bob(at)aeroelect wrote:
>
> ... SNIP
> My recommendations for optimizing Noah's adaptation
> of an SD-20 into his project is replace the SB-1
> regulator with a generic "ford" style regulator,
> add a b-lead contactor to implement fat-wire
> disconnection when parked. Take field power/
> voltage sensing directly from the battery bus
> through a fusible link then to 5A breaker, crowbar
> ovm and then to contactor+regulator bus
> connection. Placard the system against
> simultaneous operation of both alternators.
>
> Bob . . .
Bob, previously I stated my desire to use a standby 30a ER alternator in
place of the SD 8 in Z-13/8. I've been lurking as others, like Noah,
pushed the thread.
I have a B&C LR-3 for the main alt and intended to use another one for
the standby. I have a mechanical "either, or" lockout device for the two
alternator field switches. As long as the two systems are mutually
exclusive, am I correct to understand that the prohibition re dual
LR-3's, mentioned at the beginning of your post, no longer applys? And
that the suggested mods in the quote above for Noah's system would not
apply to Z-13/8 as I intend to modify it?
Thanks,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289592#289592
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z8 scrapped . . . |
>
>
>Bob, previously I stated my desire to use a standby 30a ER
>alternator in place of the SD 8 in Z-13/8. I've been lurking as
>others, like Noah, pushed the thread.
Understand.
>
>I have a B&C LR-3 for the main alt and intended to use another one
>for the standby. I have a mechanical "either, or" lockout device for
>the two alternator field switches. As long as the two systems are
>mutually exclusive, am I correct to understand that the prohibition
>re dual LR-3's, mentioned at the beginning of your post, no longer
>applys? And that the suggested mods in the quote above for Noah's
>system would not apply to Z-13/8 as I intend to modify it?
Generally. Here's some data points to ponder for
creative integration of two alternators onto a
single bus:
(1) You can have two alternators "always on" but
be aware that their ability to share total loads
is poor to nil . . . it takes special regulators
that talk to each other and direct the choir for
the proper mix of field excitation. Hence it is
recommended that two alternators be used in a main/sb
or main/aux mode where one is used to back up the
other.
(2) You can still operate in an always-on mode IF
you set the regulator setpoint for the aux alternator
about a volt lower than the main alternator. Like
the SB-1 controller functionality illustrated in
Z12. This provides an automatic transfer of load
to the aux alternator if the main shuts down.
CAUTION
This configuration offers a risk of NOT being
aware of a main alternator failure. The SB-1
regulator has circuitry that senses when the
aux alternator becomes loaded and lights a light.
That same light is use to annunciate alternator
overload . . . reduce loads until the light stops
flashing. If you don't have and SB-1, then some
simple circuit that watches alternator field
voltage and lights a light for anything over
1 volt of applied excitation is called for.
(3) You can operate in an either/or mode where
only one alternator is switched on at a time.
In this case, a low volts warning light prompts
the changeover.
CAUTION
I would advise against wiring the two systems
such than turning one alternator on disables the
other. There is no risk to hardware by having both
alternators on at a time . . . but crafting circuits
common to both systems adds a risk of single failure
disabling both alternators. Keep them separate.
-----*****-----
Beyond these three rules-of-thumb, I recommend striving
for max-cold of ship's wiring when all switches are
off. Try to limit protection for small always-hot
wires to 5A breakered, 7A fused. Strive for minimum
parts count. Strive for simple switching protocols
that limit if not eliminate any possibility that
mis-positioning of switches can go unnoticed and
negate your best laid plans and fondest wishes.
All of these ideas are NOT regulations. Just because
you do something that is not specifically illustrated
in the Z-figures is not necessarily courting unhappy
days in the cockpit. We build experimental airplanes
and exploration of alternative recipes for success
is encouraged . . . with limitations. Study, understand
and take action by DESIGN to eliminate single points
of system failure . . . which INCLUDES pilot understanding
of how the system will or will not function.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Noise in Handheld Tx signal |
At 07:21 AM 3/8/2010, Lapsley R. and Sandra E. Caldwell wrote:
>As is frequently the case, once you truly identify the root cause of
>a problem the solution is obvious.
>
>In this case we were using an external headset with the A24 hand
>held without an external PTT. In other words we were using the hand
>held Tx button for the PTT. The owners manual did not say if the
>external PTT was either recommend or necessary with an external headset.
>
>After discussing the problem with ICOM tech support they told me
>that when you press the hand held TX button it connects the internal
>mic as well as the external mic to the transmitted
>carrier. Consequently when we tried to transmit without the engine
>running the Tx signal was reasonably quite but with the engine
>running the mic in the hand held picked up the cockpit noise and
>transmitted it along with the voice from the headset mic.
>
>Correction of this problem was easy we just used an external
>PTT. Just one more wire in the cockpit
>
>I suspect that this may be common to other handhelds.
Great datapoint! Thanks for sharing.
Bob . . .
________________________________________________________________________________
| From: | James Robinson <jbr79r(at)yahoo.com> |
| Subject: | Re: Solid State Contactors -- SuperSwitch? |
good morning Bob
I was hoping you would offer some comment on these devises. Pros / cons / etc
Jim
James Robinson
Glasair lll N79R
Spanish Fork UT U77
________________________________
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Sun, March 7, 2010 6:02:40 PM
Subject: RE: AeroElectric-List: Solid State Contactors -- SuperSwitch?
>
>
>If you are
>planning on using one of these devices in your airplane, make sure you
>purchase the ones for a DC load. Some of the ones for AC load,
>require a zero crossing to switch and will not work for
>DC.
The device being discussed is offered by an aviation
equipment specialty house as a replacement for contactors
(where bi-directional current flow is needed) and another
version (relay) where uni-directional current flow will
suffice. They are expected to function in a DC power
system.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Solid State Contactors -- SuperSwitch? |
At 09:41 AM 3/8/2010, you wrote:
>good morning Bob
>I was hoping you would offer some comment on these devises. Pros / cons / etc
I've not seen detailed engineering data on any such
products to date. Certainly, the technology exists
to fabricate solid stage contactors. I think the
race car hobby/industry has been flirting with them
for some years.
My personal knowledge as to the performance of
products currently offered for sale is zero. I
would be interested seeing the detail data sheets
and/or doing lab tests on a device to look at
things like on-resistance, off leakage, transient
immunities, conducted noise, performance at temperature
extremes.
We KNOW that hard-metal contactors have VERY good
OFF and ON switching characteristics. Further, they're
simple, rugged and offer good value (service life and
performance vs. acquisition costs).
So the short answer is that pending further enlightenment
on my part, I'm not able to offer any insight.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Z8 scrapped . . . |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
longg(at)pjm.com wrote:
> John,
>
> I'm vaguely interested. What is it you are running that requires 30 amps
> of power running as a backup?
>
> Glenn E. Long
>
> --
Hi Glenn,
I like to do arc welding while flying ;-).
I was initially considering Z-19 but was always a little uncomfortable with the
finite supply of power if alt 1 quit. So it wasn't so much that I needed 30 amps
(it's a 40a unit, but pulleyed to reduce wear, so 30 a @ max cruise rpm) as
what was available at a reasonable price and weight. Ignition, fuel pump, EFI
, navcom, EFIS put my electrical needs at about 12-15 amps. With just engine
needs at about 10-12 amps.
The extra alternator gives me more comfort and less weight for the same cost than
an extra battery.
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289659#289659
________________________________________________________________________________
| From: | "Mark Richards" <flagstone(at)cox.net> |
| Subject: | Re: Z8 scrapped . . . |
Hi Bob:
Excellent description. I have a follow-up questions to #2:
(2) You can still operate in an always-on mode IF
you set the regulator setpoint for the aux alternator
about a volt lower than the main alternator. Like
the SB-1 controller functionality illustrated in
Z12. This provides an automatic transfer of load
to the aux alternator if the main shuts down.
CAUTION
This configuration offers a risk of NOT being
aware of a main alternator failure. The SB-1
regulator has circuitry that senses when the
aux alternator becomes loaded and lights a light.
That same light is use to annunciate alternator
overload . . . reduce loads until the light stops
flashing. If you don't have and SB-1, then some
simple circuit that watches alternator field
voltage and lights a light for anything over
1 volt of applied excitation is called for.
Wouldn't the aux come on whenever the system loads exceed the main
alternator's capability and the system voltage drops below the set point
of the aux regulator, not just when the main alternator fails? So set
up in that configuration, wouldn't the two LR-3's work just like the
LR-3/SB-1 combination except for the annunciation function? Then,
wouldn't you be able to tell which alternators are on and how hard each
is working by the load meters? In that situation, does it really matter
if they don't share the loads?
Thanks
Mark
________________________________________________________________________________
| Subject: | Re: Z8 scrapped . . . |
| From: | "jonlaury" <jonlaury(at)impulse.net> |
nuckolls.bob(at)aeroelect wrote:
>
> >
> >
> >
> >
>
>
> Generally. Here's some data points to ponder for
> creative integration of two alternators onto a
> single bus:
> ....SNIP....
>
> Bob . . .
Give a man a fish and he eats for a day.
Teach a man to fish and he eats for a lifetime.
I am now a fisherman.
Thanks Bob.
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289670#289670
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z8 scrapped . . . |
>
>
>Wouldn't the aux come on whenever the system loads exceed the main
>alternator's capability and the system voltage drops below the set
>point of the aux regulator, not just when the main alternator fails?
>So set up in that configuration, wouldn't the two LR-3's work
>just like the LR-3/SB-1 combination except for the annunciation
>function? Then, wouldn't you be able to tell which alternators are
>on and how hard each is working by the load meters? In that
>situation, does it really matter if they don't share the loads?
>
Very perceptive. You're correct. The caveat is to make SURE
the alternator with the higher setpoint is adequately cooled.
There have been any number of advisors calling for de-rating
an alternator's load or adjusting pulleys to slow it down . . .
with some notion of increasing service life for forestalling
early failure due to "working too hard".
Every alternator is capable of running for rated service
life (usually thousands of hours) at FULL rated output.
If the OBAM aircraft community is guilty of an important
function of well considered design is that we generally
haven't got a clue as to how well we cool . . . or don't
cool some temperature sensitive components.
There are thousands of 60A or larger alternators flying
very successfully on OBAM aircraft with very low failure
rates due to overheating. But this probably has more to
do with accidental de-rating. Few airplanes need more than
20A of snort for 90 plus percent of their missions.
Many of those builders thinks he can install some power
hungry electro-whizzy because he believes he's got lots
of headroom in the as-installed alternator.
When we certify a new alternator, rules of the game
call for an extended climb at Vy with the alternator loaded
to full rated output. We plot the temperature rise curve
in order to extrapolate the asymptote (temperature rise
ceiling). We then correct for hot day conditions. Anticipated
worst case for temperatures on diode heatsinks and stator
windings cannot exceed manufacturer's ratings.
So before you launch off to deliberately allow one
alternator to operate continuously in a current limited
condition (usually a few percent higher than nameplate
rating), be prepared to determine that the alternator
is not running with one foot in a bucket and the other
in a fire.
Back in the heyday of light twins with generators,
turning on all electro-whizzies demanded that BOTH
power sources carried their "share" of the load.
This is really easy to do with carbon pile regulators.
A simple equalizer winding added to the regulator's
magnetics would allow the two regulators to compare
notes and shift loads between generators for balancing.
http://aeroelectric.com/Pictures/Schematics/Parallel_Aircraft_Generators.jpg
Sharing was important then because service life (brush
wear) was affected by system loads. Alternators do
not suffer such problems . . . but they're more difficult
to parallel too.
Designing a system that expects one of two alternators
to operate in a current limited mode is not an automatic
recipe for failure . . . but you need to do your
homework.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z8 scrapped . . . |
>
>
>I was initially considering Z-19 but was always a little
>uncomfortable with the finite supply of power if alt 1 quit. So it
>wasn't so much that I needed 30 amps (it's a 40a unit, but pulleyed
>to reduce wear, so 30 a @ max cruise rpm) as what was available at a
>reasonable price and weight.
Service life is not enhanced by slowing it down.
Performance in the original automotive application
counted on thousands of hours under condtions far
worse than on your airplane. If you'd really like
to get 40A from it, change the pulley ratio. It
will run cooler by turning faster for the same
load.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Z8 scrapped . . . |
>
>Give a man a fish and he eats for a day.
>Teach a man to fish and he eats for a lifetime.
>
>I am now a fisherman.
>
>Thanks Bob.
Thank YOU for helping spread the value of
what this List has to share.
Bob . . .
________________________________________________________________________________
| From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
| Subject: | Solid State Contactors -- SuperSwitch? |
If you are
planning on using one of these devices in your airplane,
make sure you
purchase the ones for a DC load. Some of the ones for AC
load,
require a zero crossing to switch and will not work for
DC.
The device being discussed is offered by an aviation
equipment specialty house as a replacement for contactors
(where bi-directional current flow is needed) and another
version (relay) where uni-directional current flow will
suffice. They are expected to function in a DC power
system.
Bob . . .
One of the devices referenced previously on
this website http://www.futurlec.com/RelSS.shtml pictured an AC device
JGX-1505FB. I seem to recall way back in a previous life that some of
these
similar devices required that the output go to zero before it would shut
off. I may be wrong, since it has been many moons since I have worked
with
this device. This is why I mentioned above to be careful when selecting
your solid state relay.
Roger
________________________________________________________________________________
| Subject: | audio panel and com wiring |
| From: | Dan Ballin <dballin(at)GMAIL.COM> |
This may be obvious to most, but I found a flaw in my wiring schema
that I figured I'd share. This is somewhat specific, but I am sure
many are in a similar situation. I have a Lancair Legacy with a PMA
7000 audio panel and SL30 as com 1 and an SL40 as com 2. I wired the
panel using Z-14 (2 separate battery/alternator busses). The issue is
that I wired com 1 and the audio panel on the same buss, so if I loose
power on that buss, I have lost the ability to use a com. Since the
default for the PMA when it is off is com1, com 2 is not available.
The solution is to make sure com 1 and the audio panel are on
different busses. Of course all I have to do is hit the crossfeed and
things are good again, but in a busy stressful situation I'd rather
have the default a working com.
Dan Ballin
LEG2 #286
________________________________________________________________________________
| From: | Bill Mauledriver Watson <MauleDriver(at)nc.rr.com> |
| Subject: | Re: audio panel and com wiring |
Not obvious here. Turns out I have the same situation.
I'm not sure this concerns me. But will have to think about it. Seems
easily fixed at this point.
Thanks.
Bill Watson
RV10 with a Z-14
Dan Ballin wrote:
>
> This may be obvious to most, but I found a flaw in my wiring schema
> that I figured I'd share. This is somewhat specific, but I am sure
> many are in a similar situation. I have a Lancair Legacy with a PMA
> 7000 audio panel and SL30 as com 1 and an SL40 as com 2. I wired the
> panel using Z-14 (2 separate battery/alternator busses). The issue is
> that I wired com 1 and the audio panel on the same buss, so if I loose
> power on that buss, I have lost the ability to use a com. Since the
> default for the PMA when it is off is com1, com 2 is not available.
> The solution is to make sure com 1 and the audio panel are on
> different busses. Of course all I have to do is hit the crossfeed and
> things are good again, but in a busy stressful situation I'd rather
> have the default a working com.
>
> Dan Ballin
> LEG2 #286
>
>
>
________________________________________________________________________________
| Subject: | Re: Strobe noise |
| From: | Sam Hoskins <sam.hoskins(at)gmail.com> |
Bob, I did a few tests in response to to your questions and here is the
info.
I do not have a separate intercom, it is built into the ICOM A210
I forgot to adjust the volume knob, but. I'm pretty sure the noise is
proportionate to the volume setting.
When I disconnected the antenna at the back of the radio, all noise ceased.
Installed a Radio Shack filter, inline with the power supply. - No change in
the noise.
I disconnected the strobe power supply's 12V input, as well as the filter,
and hooked up a 12V battery I had handy and located it right next to the
PS. This eliminated all of the ship's 12V supply wiring. The noise seemed
to remain the same.
I got a hand held radio (ICOM?) and listened to it with the strobes on and
re-connected to ship's power, through the RS filter. The hand held's
squelch easily over rode the stobe noise and all seemed well.
This seems like the A210 doesn't have enough squelch control.
Any thoughts?
Sam
On Thu, Mar 4, 2010 at 7:51 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 06:14 AM 3/4/2010, you wrote:
>
> I am getting a lot of strobe noise in my headset and was hoping we could
> work through this. It is so bad that I cannot fly with the strobes on. Here
> are the basics:
>
> Aircraft: all composite Quickie Q-200<http://www.samhoskins.blogspot.com/>
>
> SkyBrite strobes/position lights http://www.airplanegear.com/skybright.htm
> Wing tip lights. Power supply is mounted on the right fuselage wall, right
> bebeath the rear wing.
>
> Radio: ICOM A210
> http://icomamerica.com/en/products/avionics/panelmount/a210/default.aspx
>
> Antenna: Bob Archer com antenna model SA-006, mounted on left side of
> fuselage, just aft of the rear wing.
> http://www.chiefaircraft.com/airsec/Aircraft/Antennas/ArcherSportcraft.html
>
> The distance between the power supply and the antenna is perhaps four feet.
>
> The Skybrite installation instructions call for using "*Strobe Extension
> Cables (light-duty, 3-conductor, 18 gauge, shielded)" *made from that
> heavy PVC stuff. I could not route this cable through the confines of my
> wing, so I used smaller diameter 3 conductor, shielded, 20 gauge, Tefzel
> wire.
>
> Symptom: When the strobes are on, there is an overall kind of a white noise
> background and the shoowp-swoowp kind of pulsing noise of the strobes. I
> can't make it go away with the squelch control, even jacked all the way up.
>
> On Bob's suggestion, I removed the strobe PS input and supplied the 12V
> with a battery positioned right next to the PS. It seemed to help a tiny
> bit, but still no joy.
>
>
> Do you have an audio system of any kind? Intercom?
> Does radio volume control knob affect what noise
> you hear? Do you hear the noise with the antenna
> disconnected from the back of the radio? Do you
> hear the noise on a hand-held radio while seated
> in the cockpit (tune to unused frequency an open
> the squelch)?
>
> Bob . . .
>
>
> Any more suggestions? Nothing is easy to do on this plane, and everything
> is hard to get at. I cannot fit a vertical antenna in the tail, since it is
> already built.
>
> Thanks,
>
> Sam
>
>
> Bob . . .
>
> ////
> (o o)
> ===========o00o=(_)=o00o========
> < Go ahead, make my day . . . >
> < show me where I'm wrong. >
> ================================
>
> *
>
> *
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: audio panel and com wiring |
At 05:21 AM 3/9/2010, you wrote:
>
>
>Not obvious here. Turns out I have the same situation.
>
>I'm not sure this concerns me. But will have to think about
>it. Seems easily fixed at this point.
This goes to the final stages of a well crafted
Failure Modes Effects Analysis . . . verification.
And the best time to do verification is sitting
in the shop, not cruising at 9K.
For folks who have intercom/audio systems, be
sure that the power-off situation for your
intercom defaults to a hard-connected feed through
of mic and headset audio to at least one comm
radio. Also, if your intercom doesn't have
it's own power switch, you might want to add one
so that a mis-behaving system can be shut off.
If the audio system doesn't have a power-down
feed-through system (like our 9009 audio isolation
amplifier) then hard-wired mic and headset jacks
as illustrated in
http://www.aeroelectric.com/Catalog/AEC/9009/9009-700L.pdf
are called for. Of course, your personal plan-B
could simply revert to a flight-bag hand-held.
What ever your plan-b, its a really good idea to
make sure "the plan" works before you need it.
Bob . . .
________________________________________________________________________________
| From: | Dan Brown <dan(at)familybrown.org> |
| Subject: | Re: Daniels positioner question |
Quoting "Robert L. Nuckolls, III" :
> speaks to the K13-1, K41 and K42 positioners in the 20 and
> 22AWG d-sub world. But a search of the document says
> nothing about the K187.
Thanks for the help and the resource. The K187 sold, but for
considerably less than the K42. In any event, it's taken care of.
Thanks again.
--
Dan Brown, KE6MKS, dan(at)familybrown.org
"Since all the world is but a story, it were well for thee to buy the
more enduring story rather than the story that is less enduring."
-- The Judgment of St. Colum Cille
________________________________________________________________________________
| From: | Kenneth Johnson <kjohnsondds(at)yahoo.com> |
Thanks Bob for taking the time to respond.- In reviewing the Z-19 wiring
diagram, I was wondering about the need for the extra battery?- I underst
and the need to be able to fly the plane without fuel being the limiting fa
ctor.- As far as load analysis, I do not have the flight instruments yet
to determine my needs.-- I do not have dual ignition, so a second batte
ry as backup for that purpose would not be needed.- Thinking from another
perspective,-as my goal is to fly into remote areas, a second battery fo
r utility use would be beneficial.- I know AirVenture, Oshkosh is still 4
months away, but if anyone will be there with their plane, let me know.-
Viewing correct-wiring practices would be beneficial-to help me.- Th
anks-to all who wrote to help me.- Ken-Johnson-=0A=0A=0A=0A________
________________________=0AFrom: "Robert L. Nuckolls, III" <nuckolls.bob@ae
roelectric.com>=0ATo: aeroelectric-list(at)matronics.com=0ASent: Sat, March 6,
2010 3:03:36 PM=0ASubject: Re: AeroElectric-List: Figure Z?=0A=0A--> AeroE
lectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob@aer
oelectric.com>=0A=0A=0A>- What Z wiring diagram fits this engine?=0A=0A
- - Z-19 is a best fit for electrically dependent engines=0A- - wit
h only one alternator.=0A> =0A> The chapter on batteries suggests an Odysse
y PC680 battery.- In doing research on this battery, it seems to be indic
ated for a motorcycle engine.- Would it provide enough cranking power?=0A
=0A- - The 680 is PLENTY . . . but you may want to consider=0A- - t
wo batteries for alternator-out operations. One for=0A- - the engine, o
ne for everything else.=0A=0A- - Do you have a load analysis? I.e. a li
sting of all=0A- - electrical accessories and what their current demand
s=0A- - are for normal operations?=0A> =0A> In reading, many times it s
uggested that grounding the engine should be done through the engine pan.
- Is there a reason why the engine pan is used VS gounding directly to th
e engine block?=0A=0A- - Don't know why anyone would do that. The most
substantial=0A- - bolt to the block that is not TORQUE sensitive is the
=0A- - best place to get a robust electrical connection to=0A- - th
e engine.=0A=0A> The Zenith 801 is a bush plane.- My goal in finishing th
e plane is to keep it as light as possible.- Over the last several months
I have "listened" in on the discussion of fuses vs breakers and whether a
transponder is needed.=0A=0A- - Breakers vs. fuses are a rather small w
eight trade off.=0A- - Especially if your failure mode effects analysis
suggests=0A- - that two batteries are called for. Transponders are onl
y=0A- - useful if somebody on the ground (1) can even see you=0A- -
on radar and (2) give a rat's you know what where you=0A- - are.=0A=0A
> Basically, I believe what a person really needs is a list of parts needed
to wire a panel and where they can be purchased.- There were good sugges
tions on fuse blocks and cup holders, but many things are missing.- I gue
ss it first begins with which Z diagram I need to use and then, I can go fr
om there.=0A=0A- - First you need to quantify the total energy budget
=0A- - for (1) normal operations and then (2) an austere budget=0A-
- for alternator out operations. Finally, decide what your=0A- - pers
onal design goals are for alternator out endurance.=0A- - If you've got
big fuel tanks then perhaps your batteries=0A- - need to be commensura
tely big too.=0A=0A> I have studied Spanish for thirty years, and can do we
ll.- However, if we had a discussion on auto parts in Spanish, I would be
lost.- In reading your discussions on many issues, I feel like the kid w
ho can tell you, "Where is the bathroom" in spanish, but is lost when asked
to say more.- As a read more and more, I catch a little more.- However
, there is a large void to fill.=0A=0A- - That's what we're here for. L
et's discover whether=0A- - a D8 Cat is needed . . . or you can shovel
enough electrons=0A- - around with a garden tractor. Also, how many yar
ds=0A- - of dirt do you need to move? This energy management=0A- -
thing is a function of TIME, LOADS and under what=0A- - conditions thos
e loads must be functioning for you=0A- - go get on the ground comforta
bly with a dead alternator.=0A=0A- - If you're flying day-vfr kinds of
missions perhaps=0A- - your energy requirements are modest . . . won't
know=0A- - until you list them and add 'em all up.=0A=0A- - Finding
all the bits and pieces to wire it up is=0A- - the stone simple part.
====0A=0A=0A
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe noise |
At 06:11 AM 3/9/2010, you wrote:
Bob, I did a few tests in response to to your questions and here is the info.
I do not have a separate intercom, it is built into the ICOM A210
I forgot to adjust the volume knob, but. I'm pretty sure the noise
is proportionate to the volume setting.
When I disconnected the antenna at the back of the radio, all noise ceased.
Okay
Installed a Radio Shack filter, inline with the power supply. - No
change in the noise.
I disconnected the strobe power supply's 12V input, as well as the
filter, and hooked up a 12V battery I had handy and located it right
next to the PS. This eliminated all of the ship's 12V supply
wiring. The noise seemed to remain the same.
Okay, the noise RADIATED not conducted.
I got a hand held radio (ICOM?) and listened to it with the strobes
on and re-connected to ship's power, through the RS filter. The hand
held's squelch easily over rode the stobe noise and all seemed well.
This seems like the A210 doesn't have enough squelch control.
A squelch control allows the operator to set a threshold
at which an incoming signal will open the receiver's audio
circuits so that the signal of interest can be heard. When
the signal goes away, it closes the audio system to mute
what ever combination of noises are present while no signal
of interest is present.
Squelch controls have no noise mitigation or filtering
effects, they only shut off the audio so that you don't
hear what ever noise is present.
Some radios do not differentiate well between signals of
interest and some forms of noise. Digital signal processing
in radios like Garmin and King know the difference between
strobes, lightning, ignition and the guy talking on the
microphone.
Your particular problem may be based on proximity. Where
is your comm antenna with respect to the strobe supply.
Can they be separated more? Unfortunately, it seems that
your strobe system is probably incapable of passing a
DO-160 radiated emissions test. If this is true, then
there may be NO solution to your problem other than getting
more distance between the antagonist and your comm antenna.
Even then, the best you can hope for is to drop the noise
to a level that allows the ICOM squelch control to overpower
it. It will ALWAYS be there to some degree. When the noise
is strong, it has the effect of de-sensitizing your receiver.
You won't hear signals that are not strong enough to overpower
the effects of the noise. This is true even when your squelch
control is capable of "shutting it off".
What strobe system are you using again?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Strobe noise |
| From: | rparigor(at)suffolk.lib.ny.us |
I had a strobe noise problem with my Vertex handheld. Like you are finding
there is not enough squelch. I called Vertex and they told me that their
radio is set up for a ducky antenna and because I connected a AAE antenna
it is just plain becoming too sensative. Sounds like a poor excuse, but
did find that Vertex was to not goingbe of any assistance.I am
using Kunzleman strobes. Bob was kind enough to send over a few noise
filters with no better results. He even offered to help Kuntzleman pass
DO-160 radiated emissions test, Kunzleman had no interest in talking to
him. Kunzleman had a few suggestions with littleresults. Forme
it made little change if I had radio use ships power or not. It made a
difference getting the strobe power supply out of fuseand onto
wingtips.One thing that was terrible was using shieldedwire
for power. i tried it and it in fact brought more RF into fuse from power
supplies, twisted pair works much better. I detail what torroids worked
for me, read careful what grounding technique worked better. i also found
that if i had AAE antenne touching fuse, i picked up a little more noise
than if i had antenna mounted slightly off fuse. i have a Becker Comm and
didn't have anywhere near the noise compared to Verttex, but after fooling
noise is almost gone.
see:
http://www.europaowners.org/forums/gallery2.php?g2_itemId=31409
Click on pics to get full details. I ordered torroids from
www.mcmaster.com
Ron Parigoris
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 09:40 AM 3/9/2010, you wrote:
>Thanks Bob for taking the time to respond. In reviewing the Z-19
>wiring diagram, I was wondering about the need for the extra battery?
That's entirely up to you. The original design goal
spoke to having a battery that could support the needs
of an electrically dependent engine (in this case I think
it was a Subaru or maybe a Mazda . . . I forget) and
second battery to support everything else.
>I understand the need to be able to fly the plane without fuel being
>the limiting factor.
That's a "need" only if you define it as such.
It's your project. My suggestions and recommendations
go to the idea of continuous improvement upon the best
we know how to do. Just because some improvement exists
does not mean you need to embrace it. If a 30 minute or
one hour alternator-out endurance capability meets your mission
requirements, so be it.
> As far as load analysis, I do not have the flight instruments yet
> to determine my needs. I do not have dual ignition, so a second
> battery as backup for that purpose would not be needed.
So perhaps you've answered your own question . . .
> Thinking from another perspective, as my goal is to fly into
> remote areas, a second battery for utility use would be
> beneficial. I know AirVenture, Oshkosh is still 4 months away, but
> if anyone will be there with their plane, let me know.
Oh shucks, you asked another question . . . don't
feel too beat up over this exercise. Very few of
our fellow builders are even aware of a value
for doing the exercise. What EVER you decide to do
after your study will make you a more competent operator
of the airplane because you UNDERSTAND more about
how it works than to 90% of the GA pilots flying
today.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Strobe noise |
| From: | Sam Hoskins <sam.hoskins(at)gmail.com> |
SkyBrite strobes/position lights http://www.airplanegear.com/skybright.htm
Wing tip lights. Power supply is mounted on the right fuselage wall, right
beneath the rear wing. They are about 4 feet apart. Not sure where else i
could park it.
Radio: ICOM A210
http://icomamerica.com/en/products/avionics/panelmount/a210/default.aspx
Antenna: Bob Archer com antenna model SA-006, mounted on left side of
fuselage, just aft of the rear wing.
http://www.chiefaircraft.com/airsec/Aircraft/Antennas/ArcherSportcraft.html
Sam
On Tue, Mar 9, 2010 at 10:04 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
>
> At 06:11 AM 3/9/2010, you wrote:
> Bob, I did a few tests in response to to your questions and here is the
> info.
>
> I do not have a separate intercom, it is built into the ICOM A210
>
> I forgot to adjust the volume knob, but. I'm pretty sure the noise is
> proportionate to the volume setting.
>
> When I disconnected the antenna at the back of the radio, all noise ceased.
>
> Okay
>
>
> Installed a Radio Shack filter, inline with the power supply. - No change
> in the noise.
>
> I disconnected the strobe power supply's 12V input, as well as the filter,
> and hooked up a 12V battery I had handy and located it right next to the
> PS. This eliminated all of the ship's 12V supply wiring. The noise seemed
> to remain the same.
>
> Okay, the noise RADIATED not conducted.
>
>
> I got a hand held radio (ICOM?) and listened to it with the strobes on and
> re-connected to ship's power, through the RS filter. The hand held's
> squelch easily over rode the stobe noise and all seemed well.
>
> This seems like the A210 doesn't have enough squelch control.
>
> A squelch control allows the operator to set a threshold
> at which an incoming signal will open the receiver's audio
> circuits so that the signal of interest can be heard. When
> the signal goes away, it closes the audio system to mute
> what ever combination of noises are present while no signal
> of interest is present.
>
> Squelch controls have no noise mitigation or filtering
> effects, they only shut off the audio so that you don't
> hear what ever noise is present.
>
> Some radios do not differentiate well between signals of
> interest and some forms of noise. Digital signal processing
> in radios like Garmin and King know the difference between
> strobes, lightning, ignition and the guy talking on the
> microphone.
>
> Your particular problem may be based on proximity. Where
> is your comm antenna with respect to the strobe supply.
> Can they be separated more? Unfortunately, it seems that
> your strobe system is probably incapable of passing a
> DO-160 radiated emissions test. If this is true, then
> there may be NO solution to your problem other than getting
> more distance between the antagonist and your comm antenna.
> Even then, the best you can hope for is to drop the noise
> to a level that allows the ICOM squelch control to overpower
> it. It will ALWAYS be there to some degree. When the noise
> is strong, it has the effect of de-sensitizing your receiver.
> You won't hear signals that are not strong enough to overpower
> the effects of the noise. This is true even when your squelch
> control is capable of "shutting it off".
>
> What strobe system are you using again?
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | =?iso-8859-1?Q?Mich=E8le_Delsol?= <michele.delsol(at)orange.fr> |
| Subject: | Wide angle LED indicators |
Ron,
You might want to check out http://www.farnell.com/datasheets/3228.pdf (Marl
leds) - I installed these, 12v., they are very bright and visible from
practically any angle - I'd say around 150, more than enough for a panel.
Only problem, sort of expensive.
Michle
-----Message d'origine-----
De: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] De la part de
rparigoris
Envoy: dimanche 7 mars 2010 22:06
: aeroelectric-list(at)matronics.com
Objet: AeroElectric-List: Wide angle LED indicators
Because of building model electric planes that we primarily fly at night, we
have collected quite the assortment of LEDs. Whenever we see something
interesting, usual end up getting a few samples to fool with. collection is
from the big 4 > Mouser, Digikey, Allied and Newark as well as Best Hong
Kong, Hosfelt and others.
Now that it's time to install indicators and warning LEDs on Europa XS we
quickly came to realization that unless a warning indicator is in your
direct line of vision, it ain't gonna get your attention too quickly during
when operated in direct sunlight. we are going to use some nice black
bezeled indicators for non-critical indicators. Pepboys and Advace Auto are
going to be suppliers for wide angled warning LEDs! you see we want several
warning LEDs by knees. For three pretty important LEDs, Rotax 914 TCU Red
and Orange and Oil pressure going to use a cluster of 4 LEDs from Advanced.
These are super bright and the cluster of 4 is mounted on a small circuit
board. By drilling a cluster of 4 holes and allowing tips stick out a bit,
the tips glow plenty bright, available in Red, and Yellow at least. The neat
thing is there is no flange on side of LEDs. For other warning LEDs, Pepboys
sell single LEDs that are ultrabright. Same thing, no flange on sides and
long enough to allo!
w tip to stick out of panel, small OD, available in red, Yellow and
probably blue at least. Both Pepboys and Advanced sell a neat wide angle LED
where the face has a counterbore, may be 5/16" or 3/8" OD (I forget) but
very wide angle viewing but only available in Blue, White and Yellow/Orange,
no Red.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Hyper-Bri
ght-Amber-LED-Automotive-Bulb-Pair-Jam-Strait_6120511-P_N3157A_A%7CGRP2044__
__
I got a pack of 3 from Pepboys but these are probably similar (didn't see
these in Advance and Pepboys website is poor at best):
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_HyperLED-
Red-Alpena_6120501-P_N3157A_A%7CGRP2044____
you can get these in Yellow/Orange and Blue, I didn't see in Red:
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_194-WHITE
-LED-BULBS-Pilot_6460030-P_N3157A_A%7CGRP2044____
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289549#289549
________________________________________________________________________________
| Subject: | Running Big Battery Wire Through Firewall |
| From: | "DaveG601XL" <david.m.gallagher(at)ge.com> |
I have a friend who is building a metal airplane where the battery will be mounted
in the tail with a big 2GA positive wire going through the firewall. I did
not run into this on my airplane so I am asking what is the best way to lead
this wire through the firewall. Do you run a continuous wire with a grand-daddy
grommet or use a bolted stud on either side? We can figure the fire protection
part out seperately after we find out which way is best for routing the
electrical path.
Thanks,
--------
David Gallagher
601 XL/Jabiru 3300
First flight 7/24/08
116.5 hours and holding (incorporating upgrade)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289895#289895
________________________________________________________________________________
| From: | Corey Crawford <corey.crawford(at)gmail.com> |
| Subject: | Re: Running Big Battery Wire Through Firewall |
I'm not sure if this is exactly what you are asking about, but this is the
product I'm using for my firewall power pass-through.
Feed-through Terminal<http://www.westmarine.com/webapp/wcs/stores/servlet/p
roducte/10001/-1/10001/144078/377%20710%201635/0/High%20Amp%20Distribution/
Primary%20Search/mode%20matchallpartial/0/0?N=377%20710%201635&Ne=0&Ntt
=High%20Amp%20Distribution&Ntx=mode%20matchallpartial&page=CategoryDi
splayLevel1&isLTokenURL=true&storeNum=5002&subdeptNum=9&classNum=11
9#>
--
Corey Crawford
corey.crawford(at)gmail.com
On Wed, Mar 10, 2010 at 7:06 AM, DaveG601XL
wrote:
david.m.gallagher(at)ge.com>
>
> I have a friend who is building a metal airplane where the battery will b
e
mounted in the tail with a big 2GA positive wire going through the firewall
.
I did not run into this on my airplane so I am asking what is the best way
to lead this wire through the firewall. Do you run a continuous wire with
a
grand-daddy grommet or use a bolted stud on either side? We can figure the
fire protection part out seperately after we find out which way is best for
routing the electrical path.
>
> Thanks,
>
> --------
> David Gallagher
> 601 XL/Jabiru 3300
> First flight 7/24/08
> 116.5 hours and holding (incorporating upgrade)
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=289895#289895
________________________________________________________________________________
| From: | Jeff Page <jpx(at)qenesis.com> |
| Subject: | Re: Failure modes with Z14 |
Joe,
Thanks for taking the time to look at my diagram. It is comforting to
know that someone else doesn't see any obvious goofs.
I have finished the diagram of the low voltage monitor. Its link is
now available at the same page:
http://www.qenesis.com/tundra/Electrical
Note that I have drawn the diagram, but not yet breadboarded it, so it
may not function as intended.
I would be particularly interested in any changes that would make the
design better handle the DO-160 nasties.
Jeff Page
Dream Aircraft Tundra #10
> I looked over your schematic at
> http://www.qenesis.com/tundra/Electrical/Tundra_Power_Wiring.pdf and
> it looks very good. It would be interesting to see the internal
> schematic for the low voltage module and the purpose of the wires
> connected to it from switches. I am not saying that anything is
> wrong, only that I do not know what is inside of that box and how it
> works.
> Good job.
> Joe
________________________________________________________________________________
| Subject: | Re: Running Big Battery Wire Through Firewall |
| From: | jaybannist(at)cs.com |
Dave,
I used a Moroso thru panel battery connector, P/N 74145. I think I got it
from Summit Racing on line.
Jay Bannister
-----Original Message-----
From: DaveG601XL <david.m.gallagher(at)ge.com>
Sent: Wed, Mar 10, 2010 8:06 am
Subject: AeroElectric-List: Running Big Battery Wire Through Firewall
e.com>
I have a friend who is building a metal airplane where the battery will be
mounted in the tail with a big 2GA positive wire going through the firewal
l. I
did not run into this on my airplane so I am asking what is the best way
to lead
this wire through the firewall. Do you run a continuous wire with a grand
-daddy
grommet or use a bolted stud on either side? We can figure the fire prote
ction
part out seperately after we find out which way is best for routing the
electrical path.
Thanks,
--------
David Gallagher
601 XL/Jabiru 3300
First flight 7/24/08
116.5 hours and holding (incorporating upgrade)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289895#289895
========================
===========
========================
===========
========================
===========
========================
===========
________________________________________________________________________________
| Subject: | Running Big Battery Wire Through Firewall |
David,
I can tell you there is more than one way to skin a cat, but if you look
at one of the gazillion Piper Cherokees out there, the cable runs from
under the back seat along the left panel through the generally dry
rotted grand-daddy grommet to the contactor mounted on the firewall.
Size does matter but for 2 or 4 GA that won't make a difference. Good
enough for Piper...
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
DaveG601XL
Sent: Wednesday, March 10, 2010 9:06 AM
Subject: AeroElectric-List: Running Big Battery Wire Through Firewall
I have a friend who is building a metal airplane where the battery will
be mounted in the tail with a big 2GA positive wire going through the
firewall. I did not run into this on my airplane so I am asking what is
the best way to lead this wire through the firewall. Do you run a
continuous wire with a grand-daddy grommet or use a bolted stud on
either side? We can figure the fire protection part out seperately
after we find out which way is best for routing the electrical path.
Thanks,
--------
David Gallagher
601 XL/Jabiru 3300
First flight 7/24/08
116.5 hours and holding (incorporating upgrade)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289895#289895
________________________________________________________________________________
| From: | Jeff Page <jpx(at)qenesis.com> |
There is a lot of good discussion on this list about improving our
designs based on our goals.
Some of these goals are based on our personal flight profiles, but
some speak to best practices. It is the best practices I am discussing
here.
Some of the best practices have been established for us by the FAA,
and others we have worked out by "ourselves" - Thanks Bob !
We talk about these best practices as if we all know what all of them
are, but I suspect that is not true, since they are not collected in a
single place. I know it is not for me.
I think what might be very helpful, is a checklist of design
goals/best practices. This is something we could use after completing
our designs to ensure that we have not overlooked something important
and that we are aware of everything before we start pulling wires
through the wings.
I will start it off:
DESIGN GOAL/ BEST PRACTICE CHECKLIST
- Unfused, high current wires - minimize length to 6" or less
- Consider voltage drop as well as current capability when sizing wires
- Fuses or circuit breakers are intended to protect wire, not devices
- Avoid bringing high current wires to the instrument panel using relays
- Use a relay rather than a switch for currents above 7A
- Avoid single points of failure when possible
Use two single-pole switches in place of a single switch for a critical
item, such as ignition
- Consider ground paths to avoid ground loops
- Use higher capability components than needed, when robust packaging is
advantageous
- Make sure you can shut it off if it is misbehaving
- Consider the effect of failure of any single electrical device
- Simpler is more reliable, easier to build, troubleshoot and maintain
- More expensive items still fail - less expensive items may be quite suitable
- Plan alternatives, so devices are not critical to safe flight
Please add to this list !
Jeff Page
Dream Aircraft Tundra #10
________________________________________________________________________________
| From: | Peter Pengilly <peter(at)sportingaero.com> |
| Subject: | Re: Design Goals |
Jeff,
That's an great idea, and an excellent start. My suggestion would be to
try to order the goals into logical grouping, for example overall system
goals (Make sure you can shut it off if it is misbehaving), principles
(Fuses or circuit breakers are intended to protect wire, not devices),
and wiring goals (Unfused, high current wires - minimize length to 6" or
less )
I would re-order your list like this - please feel free to change the
names, changes words, add or subtract
Peter
System Goals
- Any single failure should not take out any flight critical service
(was, Avoid single points of failure when possible)
- Make sure you can shut it off if it is misbehaving
- Simpler is more reliable, easier to build, troubleshoot and maintain
(Sydney Camm <http://www.historylearningsite.co.uk/sidney_camm.htm> -
"Simplicate and add lightness")
- Plan alternatives, so devices are not critical to safe flight
- Following the failure of any single function or device the pilot
should be able to safely continue flying with a maximum of ?2? switch
selections
Principles
- Fuses or circuit breakers are intended to protect wire, not devices
- Avoid bringing high current wires to the instrument panel using relays
- Use a relay rather than a switch for currents above 7A
- Use two single-pole switches in place of a single switch for a
critical item, such as ignition
- Use higher capability components than needed, when robust packaging is
advantageous
- Consider the effect of failure of any single electrical device
- More expensive items still fail - less expensive items may be quite
suitable
Wiring Goals
- Unfused, high current wires - minimize length to 6" or less
- Consider voltage drop as well as current capability when sizing wires
- Consider ground paths to avoid ground loops
Jeff Page wrote:
>
> There is a lot of good discussion on this list about improving our
> designs based on our goals.
>
> Some of these goals are based on our personal flight profiles, but
> some speak to best practices. It is the best practices I am discussing
> here.
>
> Some of the best practices have been established for us by the FAA,
> and others we have worked out by "ourselves" - Thanks Bob !
>
> We talk about these best practices as if we all know what all of them
> are, but I suspect that is not true, since they are not collected in a
> single place. I know it is not for me.
>
> I think what might be very helpful, is a checklist of design
> goals/best practices. This is something we could use after completing
> our designs to ensure that we have not overlooked something important
> and that we are aware of everything before we start pulling wires
> through the wings.
>
> I will start it off:
>
> DESIGN GOAL/ BEST PRACTICE CHECKLIST
> - Unfused, high current wires - minimize length to 6" or less
> - Consider voltage drop as well as current capability when sizing wires
> - Fuses or circuit breakers are intended to protect wire, not devices
> - Avoid bringing high current wires to the instrument panel using relays
> - Use a relay rather than a switch for currents above 7A
> - Avoid single points of failure when possible
> Use two single-pole switches in place of a single switch for a critical
> item, such as ignition
> - Consider ground paths to avoid ground loops
> - Use higher capability components than needed, when robust packaging is
> advantageous
> - Make sure you can shut it off if it is misbehaving
> - Consider the effect of failure of any single electrical device
> - Simpler is more reliable, easier to build, troubleshoot and maintain
> - More expensive items still fail - less expensive items may be quite
> suitable
> - Plan alternatives, so devices are not critical to safe flight
>
> Please add to this list !
>
> Jeff Page
> Dream Aircraft Tundra #10
>
>
________________________________________________________________________________
| From: | rparigor(at)suffolk.lib.ny.us |
I guess a little off topic,I have a question about plumbing my
manifold pressure gauge. An avionics shop mentioned to mea while
back (now out of business)it is a good idea to have ability to drain
manifold pressure line once a year. They said even with a normal aspirated
engine, crud makes its way into gauge and clogs up the works. He said they
install near the gauge an easy way to create a leak once a year and let
crud get sucked through engine. I don't know if they use a needle valve,
some sort of valve, a capped flair or?? i have a Rotax 914 that has
ability to not only suck, but pressurize as well, being a turbo oil can
certainly be in themix as well. I have a UMA dual diaphragm
2+1/4" gauge, UMA said they recommend ability to purge line once a
year but offer no guidance as far as what sort of hardware to use to
create leak. any ideas or suggestions?
Thx.
Ron Parigoris
________________________________________________________________________________
| From: | "David E. Nelson" <david.nelson(at)pobox.com> |
Hi Ron,
Why not place a clear, in-line "fuel-filter" as found at motorcycle/small engine
shops?
Just an idea,
/\/elson
~~ Lately my memory seems to be like a steel trap .... without any spring. ~~
On Wed, 10 Mar 2010, rparigor(at)suffolk.lib.ny.us wrote:
> I guess a little off topic, I have a question about plumbing my manifold pressure
gauge. An avionics shop mentioned to me a while back (now out of business)
it is a good idea to have ability to
> drain manifold pressure line once a year. They said even with a normal aspirated
engine, crud makes its way into gauge and clogs up the works. He said they
install near the gauge an easy way to
> create a leak once a year and let crud get sucked through engine. I don't know
if they use a needle valve, some sort of valve, a capped flair or?? i have a
Rotax 914 that has ability to not
> only suck, but pressurize as well, being a turbo oil can certainly be in the
mix as well. I have a UMA dual diaphragm 2+1/4" gauge, UMA said they recommend
ability to purge line once a year but
> offer no guidance as far as what sort of hardware to use to create leak. any
ideas or suggestions?
> Thx.
> Ron Parigoris
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Failure modes with Z14 |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Jeff,
If wire 2223 or its connections fail, power will be lost to the essential bus.
Wire 2222 should be connected directly to the E-Bus.
Now I see what those 4 wires are for that connect between the low voltage module
and grounded switches. Any one of the switches can enable the low voltage
module. The diodes isolate the 4 switches from each other. Did you design
the low voltage warning module yourself? Are you an electrical engineer? Let
us know how it works.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=289958#289958
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | RE: Solid State Contactors -- SuperSwitch? |
Thank you everyone for the feedback.
Bob, I talked with Lamar Technologies' Jim Errington, their Sales &
Marketing Manager. I let him know that you are interested in examining and
testing their solid state contactor relays. He's also very interested in
providing you some of their contactors for testing and to get familiar with
them. I gave him the phone number on the AeroElectric home page
(620-886-3403) for you so you may have already heard from him. If you have
not, Jim's contact info is jime(at)lamartech.com, phone: 360-651-6666.
Their technical support guy, Alan Saldecki, provided a couple pdf files with
a bit more information on their SuperSwitches - I've attached only one of
them to keep this file size small. One thing that's different in their spec
file vs. the Aircraft Spruce page is that it's rated for 80 A continuous
rather than 100A and that various with ambient temperature.
They have a bunch of the SuperSwitches flying in a Cessna Corvalis for
certification testing, or something like that. They also report they have a
number of experimentals flying with them without problems.
If you are still interested in looking into them, I'll wait to see what you
think when you open one up and test it before deciding to use them in our
power system. Note that with my 28V, high current demand system (electric
A/C, live in Houston) I'm already stuck with contactor relays in their price
range - so, cost isn't a factor so much as reliability and weight.
Thanks,
Valin Thorn
Lancair Legacy project
Houston, TX USA
From: Valin & Allyson Thorn [mailto:thorn(at)starflight.aero]
Sent: Saturday, March 06, 2010 3:05 PM
Subject: Solid State Contactors -- SuperSwitch?
Hello,
Has anyone had experience with the solid state contactors from Lamar
Technologies they call a SuperSwitch? See this Aircraft Spruce link for
info:
http://www.aircraftspruce.com/catalog/elpages/superSwitch.php
I know they're expensive - but, we're already in that category of contactor
with the need for 28V high continuous current contactors (100 A alternator,
all electric A/C). We already have very nice Blue Sea high capacity
contactors that are hermetically sealed (~$150 each). They weigh about a
pound each, though, and the significant weight savings with these solid
state contactors looks good.
I'd appreciate comments and advice.
Thanks,
Valin Thorn
Legacy
Houston, TX USA
cid:image001.jpg(at)01CAB316.6FD47F10
________________________________________________________________________________
| From: | "Allen Fulmer" <afulmer(at)charter.net> |
| Subject: | Running Big Battery Wire Through Firewall |
I used stud pass through I purchased from West Marine online.
Allen Fulmer
RV7 Finish wiring
________________________________________________________________________________
| From: | "glen matejcek" <aerobubba(at)earthlink.net> |
| Subject: | RE: Running Big Battery Wire Through Firewall |
Hi Dave-
I used Bob's shower bar arrangement, and am quite happy with the result. I
actually ended up with two penetrations, one aircraft left that carries the
engine control cables and higher power electrical lines, and one aircraft
right that carries sensor lines.
glen matejcek
aerobubba(at)earthlink.net
> Subject: AeroElectric-List: Running Big Battery Wire Through Firewall
> From: "DaveG601XL" <david.m.gallagher(at)ge.com>
>
>
> I have a friend who is building a metal airplane where the battery will
be mounted
> in the tail with a big 2GA positive wire going through the firewall. I
did
> not run into this on my airplane so I am asking what is the best way to
lead
> this wire through the firewall. Do you run a continuous wire with a
grand-daddy
> grommet or use a bolted stud on either side? We can figure the fire
protection
> part out seperately after we find out which way is best for routing the
> electrical path.
>
> Thanks,
>
> --------
> David Gallagher
> 601 XL/Jabiru 3300
> First flight 7/24/08
> 116.5 hours and holding (incorporating upgrade)
________________________________________________________________________________
| From: | "Jay Hyde" <jay(at)horriblehyde.com> |
Hey there Bob,
I have been trying to send you mails to your address but do not seem to be
getting through- would you send me a mail to jay(at)horriblehyde.com to see if
I am getting the correct address?
Thanks
Jay
________________________________________________________________________________
| Subject: | RE: Running Big Battery Wire Through Firewall |
Dave,
Lancairs often use Industrial Cable Grips for pass through items. They
look good, are leak proof and do a great job of protecting the wire(s).
Much better than a grommet and very easy to install.
I too like the stud bolts ala West Marine but find that also creates
addition exposed connections for stuff to rub against.
Glenn
> Subject: AeroElectric-List: Running Big Battery Wire Through Firewall
> From: "DaveG601XL" <david.m.gallagher(at)ge.com>
>
>
> I have a friend who is building a metal airplane where the battery
will
be mounted
> in the tail with a big 2GA positive wire going through the firewall.
I
did
> not run into this on my airplane so I am asking what is the best way
to
lead
> this wire through the firewall. Do you run a continuous wire with a
grand-daddy
> grommet or use a bolted stud on either side? We can figure the fire
protection
> part out seperately after we find out which way is best for routing
the
> electrical path.
>
> Thanks,
>
> --------
> David Gallagher
> 601 XL/Jabiru 3300
> First flight 7/24/08
> 116.5 hours and holding (incorporating upgrade)
________________________________________________________________________________
| Subject: | Re: Running Big Battery Wire Through Firewall |
| From: | "DaveG601XL" <david.m.gallagher(at)ge.com> |
Thanks for the input. I think we have decided on the single wire through a flange
& tube arrangement with RTV protection. I guess that is what was referenced
as the "shower bar" approach. First time I heard it called that, but I guess
it fits.
Great to have a discussion board such as this!
--------
David Gallagher
601 XL/Jabiru 3300
First flight 7/24/08
116.5 hours and holding (incorporating upgrade)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290029#290029
________________________________________________________________________________
| From: | Jeff Page <jpx(at)qenesis.com> |
| Subject: | AeroElectric List: Low Voltage Module |
Joe,
Wow - sharp eyes. I have modified the Power diagram to move the wire
from the Essential Bus Relay to directly feed the Essential Bus. No
use having independent paths that are not independent ! Thanks Joe !
Yes, I did design the Low Voltage Module myself. I decided there
wasn't room on my panel for two ammeters that I was rarely going to
look at anyway and that a low voltage light would tell me (and my
wife, who is also a pilot) everything we need to know in flight. I
expect a I can connect a shunt to the Dynon and see what the load
current is if need be.
I wanted something that monitored both charging systems.
I wanted something that the indicator lights blinked, making them
easier to notice.
I graduated many years ago as an Electrical Technologist, although I
have spent most of my career in IT.
There are a lot of fancy new customizable chips that could probably do
this entire circuit, but I don't know anything about them, so I used
old components I am familiar with.
Did you really want an explanation of how the circuit works ? If not,
skip to the next message in this forum.
Keep in mind as you read this, that I have drawn the schematic, but
not breadboarded this circuit, so it may require changes to function
as intended.
Diodes D1-D4 bring the battery voltages into the module, while keeping
them isolated. Any one of D5 to D8 provide ground to the module to
turn it on. This means I will be reminded to turn off any switch that
would allow a battery to discharge if I accidentally leave it on.
D2 and D3 take power from whichever battery has the highest voltage to
power the module. I chose to run the electronics at 5 volts, so the
module will complain about low voltage at battery voltages far below
what a functioning battery will produce. U1 is a transistor-sized
voltage regulator needing no external components to set its voltage.
R1 and R2 form a voltage divider to create a 2.0 volt reference, which
is used by all the comparators.
D4 feeds the voltage divider for the primary battery/alternator.
R3 and R4 could have been a single resistor, but I split the value.
This makes it easier to make a small change to tweak the exact voltage
for the comparator. I think fixed resistors are more reliable than
adjustable ones. Also, by putting the C4 between R3 and R4, and
voltage variations that still occur will be divided by two before
being seen by the comparator.
R6 provides positive feedback for hysteresis. So the comparator
functions like this. Assume all is well with the alternator, so the
battery bus is say 14 volts. The voltage at the +ve comparator input
will be above the reference of 2.0V. The open collector transistor
output of the comparator is off. So R7 pulls the output up toward 5V.
It won't get there, since a voltage divider is created with R15,
which is turning on Q1, which holds Q2 off and there is no current
through the indicator LED.
Now an alternator failure. As the voltage on the battery bus
decreases to 13.0V, the +ve comparator input decreases and as soon as
it decreases barely below the 2.0V reference, the comparator flips and
turns on its output transistor, taking its output to ground. This
changes the direction of current through the feedback resistor R6,
changing the voltage divider, which now presents 1.85 volts to the +ve
input, keeping the comparator from flipping back. The bus voltage
must rise to 13.8 volts before the +ve input reaches 2.0V.
Q1 is now off, which means Q2 is driven by U3, which is a timer chip.
R8, R9 and C6 form a voltage divider. When the power is first applied
to the circuit, there is no voltage across C6, so the Trigger input is
low, producing a high Output. C6 charges, until the Threshold voltage
is reached, approximately 2/3 of 5V. The Output changes to low and
internally, an open collector transistor pulls the Discharge pin to
ground. C6 discharges through R9 into the Discharge pin. When the
voltage at the Trigger pin reaches approximately 1/3 of 5V, the output
goes high, Discharge open circuits and the charging cycle repeats.
C6 charges through R8 and R9, but discharges through only R9, so
charging takes longer. This means the LED will be blinking, but will
be on about 80% of the time. I figured the blinking would attract
attention, but having it mostly on means that a quick glance is most
likely to find the LED lit. Decreasing R8 and R9 will increase the
blinking frequency. Changing the ratio of R8 to R9 will alter the
duty cycle.
D1 feeds a voltage divider for an identical comparator circuit for the
Aux battery/alternator. Since the blinking circuit is common to both,
if both indicators are on, they will blink in unison.
The third comparator U2-C and the second voltage regulator U4 are to
control the brightness of the indicators. I find indicators bright
enough to be seen daytime to be very annoying at night. Manual
control to dim them could mean that I might not see a dimmed indicator
in sunlight. So the solution is to automatically dim at night.
R10, R11 and R12 form a voltage divider, which is compared to the same
2.0V reference. R11 is a resistor that changes it's resistance in the
presence of light. The one I have has not been manufactured for a
very long time. I will need to find an alternative part and tweak the
voltage divider accordingly. The current values are chosen so that
during daytime the voltage at the +ve comparator input causes the
output to be high.
U4 is an adjustable voltage regulator the size of a transistor. It
has no ground reference, but adjusts its output voltage so that the
voltage across R17 is always 1.2V. So during the daytime, the voltage
divider of R17 and R18 causes the regulator output to be 7.7V,
producing 23mA through the LED, making it quite bright. At night, the
output of the comparator is low, including R16 in parallel with R18,
changing the voltage divider so that the regulator output is 5.3V,
producing 12mA through the LED, so it glows dimly. Depending on the
LED, R18 and R16 can be changed to set the desired brightness.
Since a 14 pin dip includes four comparators, I had one left over. I
thought perhaps the day/night auto dimming might be useful for other
instrument lights. So U2-D just duplicates U2-C. To guarantee
isolation between the Primary and Aux busses, I used an opto-isolator
U6 to provide an open collector output that can be connected to
another circuit someday.
The capacitors and voltage regulators should make this circuit
relatively immune to voltage variations and noise on the busses.
The circuit as shown may be damaged by a high voltage spike. A change
I made since posting the original diagram is to add 20V zener diodes
in parallel with C4 and C9, which will protect the comparator inputs.
However, the maximum ratings for the regulators is 30 to 40 V. So I
need something to protect them. Does anyone have any recommendations ?
Jeff Page
Dream Aircraft Tundra #10
> Jeff,
> If wire 2223 or its connections fail, power will be lost to the
> essential bus.
> Wire 2222 should be connected directly to the E-Bus.
>
> Now I see what those 4 wires are for that connect between the low voltage
> module and grounded switches. Any one of the switches can enable the low
> voltage module. The diodes isolate the 4 switches from each other. Did you
> design the low voltage warning module yourself? Are you an electrical
> engineer? Let us know how it works.
> Joe
________________________________________________________________________________
| Subject: | Re: Running Big Battery Wire Through Firewall |
| From: | rparigor(at)suffolk.lib.ny.us |
Shower bar arrangement
"flange & tube arrangement with
RTV protection"
Would it be a bad thing to incorporate
tubing/hoses in a shower bar arrangement along with wires as compared to
using bulkhead fittings for the tubes/hoses?
On my Rotax 914 I need
to get these tubes/hoses aft of firewall:
Maniifold Pressure,
probably 1/4" Nylaflow
Two tubes for mixture control
(~3/16" Viton)
Thx.
Ron Parigoris
.
________________________________________________________________________________
| Subject: | Re: Running Big Battery Wire Through Firewall |
| From: | thomas sargent <sarg314(at)gmail.com> |
David:
Actually it's the end cut off a toilet grab bar. It's stainless steel and -
very important - it turns a 90 degree angle. It's a 90 deg elbow on a
flange. I have always thought, though I can't prove it, that the 90 deg.
bend adds substantially to the fire-barrier qualities of the tube. It's
fairly thin wall tube, but the flange is pretty thick, so the only downside
is it's kind of heavy. One made specifically for this purpose would
probably have half the weight.
On Thu, Mar 11, 2010 at 1:02 PM, DaveG601XL wrote:
> david.m.gallagher(at)ge.com>
>
> Thanks for the input. I think we have decided on the single wire through a
> flange & tube arrangement with RTV protection. I guess that is what was
> referenced as the "shower bar" approach. First time I heard it called that,
> but I guess it fits.
>
> Great to have a discussion board such as this!
>
>
--
Tom Sargent
________________________________________________________________________________
| From: | "glen matejcek" <aerobubba(at)earthlink.net> |
| Subject: | RE: Running Big Battery Wire Through Firewall |
HI David-
To expand on this topic a bit, the preferred sealant is an intumescent fire
block, not RTV. You can get it in the aviation department of Lowe's et al.
I believe Bob has a tutorial on his website that covers all the detail.
All my sensor lines, including MP, pass thru these fittings.
glen matejcek
aerobubba(at)earthlink.ne
________________________________________________________________________________
| Subject: | RE: Running Big Battery Wire Through Firewall |
Correct, also available at Ace and other fine Aero-motive department
stores. Cost is about $10/tube. After that you can install the remote
halon tubing and tips to put out the fire once it really gets going.
That will set ya back $500-$600 for the push type with a 5 lb tank.
http://www.acehardware.com/family/index.jsp?categoryId=2624911
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of glen
matejcek
Sent: Friday, March 12, 2010 9:58 AM
Subject: AeroElectric-List: RE: Running Big Battery Wire Through
Firewall
HI David-
To expand on this topic a bit, the preferred sealant is an intumescent
fire
block, not RTV. You can get it in the aviation department of Lowe's et
al.
I believe Bob has a tutorial on his website that covers all the detail.
All my sensor lines, including MP, pass thru these fittings.
glen matejcek
aerobubba(at)earthlink.ne
________________________________________________________________________________
| Subject: | Bob, Question on your WigWag flasher using a flasher |
relay
| From: | "Brantel" <bchesteen(at)hughes.net> |
Bob,
On page 3.0 of your diagram on the single switch solution to a wig wag using the
flasher relay.....
You state that we can use a 15 amp breaker and 16awg wire for up to 2ea 100w lamps.
Is this correct or a typo? Since when not in wigwag mode the full combined current
will flow thru one 16awg wire, this seams to breaks some rules????
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290113#290113
________________________________________________________________________________
| Subject: | Re: Flap motor draw for Rv-7A |
| From: | thomas sargent <sarg314(at)gmail.com> |
I've been using a 5 amp fuse. I used fairly light wire - 20 or 22 I think -
because the use of the flap motor is very intermittent. It's just on for a
few seconds once or twice and then you don't use it again for an hour. You
can tolerate a wire which, under continuous use, would have a noticeable
temperature rise.
--
Tom Sargent
________________________________________________________________________________
| From: | <robert.mccallum2(at)sympatico.ca> |
| Subject: | Flap motor draw for Rv-7A |
True as far as it goes=2C BUT the voltage drop on the small wire=2C dependi
ng on its length=2C may mean that the full design power of the motor is not
available. This may or may not be significant depending on=2C amongst othe
r things=2C your airspeed. It's also a little hard on the motor running it
at reduced voltage. Generally wires feeding motors should take voltage drop
into consideration so that the motor receives=2C as near as possible=2C fu
ll design voltage during operation however short or intermittant that opera
tion may be.
Bob McC
Date: Fri=2C 12 Mar 2010 11:03:16 -0700
Subject: Re: AeroElectric-List: Flap motor draw for Rv-7A
From: sarg314(at)gmail.com
I've been using a 5 amp fuse. I used fairly light wire - 20 or 22 I think
- because the use of the flap motor is very intermittent. It's just on for
a few seconds once or twice and then you don't use it again for an hour. Y
ou can tolerate a wire which=2C under continuous use=2C would have a notice
able temperature rise.
--
Tom Sargent
________________________________________________________________________________
| From: | "Jay Hyde" <jay(at)horriblehyde.com> |
Uh-oh, Bob Lee pointed out to me that there are more than one Bob on the
list. I am trying to get hold of Bob Nuckolls...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jay Hyde
Sent: 11 March 2010 05:03 PM
Subject: AeroElectric-List: Calling Bob...
Hey there Bob,
I have been trying to send you mails to your address but do not seem to be
getting through- would you send me a mail to jay(at)horriblehyde.com to see if
I am getting the correct address?
Thanks
Jay
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 01:38 PM 3/12/2010, you wrote:
>
>Uh-oh, Bob Lee pointed out to me that there are more than one Bob on the
>list. I am trying to get hold of Bob Nuckolls...
No problem Jay. I'm trying to chase down some missing parts.
Will reply directly to you shortly.
Bob . . .
________________________________________________________________________________
| Subject: | Flap motor draw for Rv-7A |
| From: | "Matt Prather" <mprather(at)spro.net> |
My hazy recollection is that running reduced voltage being hard on motors
depends on the type of motor.. I looked up what appears to be the
replacement motor and found a link here:
http://www.clickautomation.com/PDF/items/9234S004.PDF
I believe the peak current at 12V is found when stalled (RPM=0). Reducing
the Voltage should lower the current, reducing the temperature.
Again, my hazy recollection is that AC induction motors may not like
running with sagging voltage. Hopefully someone can remind me how this
works..
Matt-
>
> True as far as it goes, BUT the voltage drop on the small wire, depending
> on its length, may mean that the full design power of the motor is not
> available. This may or may not be significant depending on, amongst other
> things, your airspeed. It's also a little hard on the motor running it at
> reduced voltage. Generally wires feeding motors should take voltage drop
> into consideration so that the motor receives, as near as possible, full
> design voltage during operation however short or intermittant that
> operation may be.
>
>
> Bob McC
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Flap motor draw for Rv-7A |
At 02:02 PM 3/12/2010, you wrote:
>
>My hazy recollection is that running reduced voltage being hard on motors
>depends on the type of motor.. I looked up what appears to be the
>replacement motor and found a link here:
>
>http://www.clickautomation.com/PDF/items/9234S004.PDF
>
>I believe the peak current at 12V is found when stalled (RPM=0). Reducing
>the Voltage should lower the current, reducing the temperature.
>
>Again, my hazy recollection is that AC induction motors may not like
>running with sagging voltage. Hopefully someone can remind me how this
>works..
A DC motor doesn't really have a "hard" voltage rating.
I.e., the nameplate only speaks to performance at the
nameplate voltage. In the case of the motor specs cited
above, you won't find all that good stuff on any nameplate.
I've purloined the speed/torque/amps curve from the
data sheet cited above and added a few more features
which can be seen here:
http://www.aeroelectric.com/Pictures/Curves/Speed-Torque-Current_Curve.jpg
The 12v speed/torque plot is shown in brown along with
the current torque curve shown in blue. Note that
the output of a DC motor is proportional to current
so ONE plot suffices for all conditions. The speed/torque
curve is bounded a the left end by applied voltage
divided by Ke (back EMF constant). With 12v applied and
zero load, we see about 6200 rpm. 9V applied yields
about 4600 rpm. 6V applied drops the no-load speed
to 1/2 the 12v value or 3100 rpm.
The right end of these curves is bounded by the internal
resistance of the motor. At zero rpm, the current that
flows in the motor is volts/ohms. 6V yields 1/2 the
locked-rotor current of 12V. Since output torque is
absolutely proportional to current, it holds further
that stall torque is proportional to applied voltage.
Now, suppose it takes 20 oz-in to move your flaps
a the top of the white arc on your IAS display.
Let's assume further that your alternator is working
and there's about 14 volts applied to the motor.
14V applied to this motor gives you a no-load speed
of about 7600 rpm and a stall torque of 48 oz in.
Let's say your 20 oz-in working load slows the motor down
to about 4300 rpm and the motor will draw just under
7.5 amps. Now, battery only the bus drops to 12v and
the speed comes down to about 3000 rpm. It will now
take about 1.5 times longer to extend the flaps. But
the current is still 7.5 amps. If your battery is
on its last legs and the applied voltage drops to
9V, 20 oz-in of load runs the motor at 1500 rpm.
Flap extension time is now 5 times longer than
at 14v. Guess what? The current is still 7.5A. As
the battery continues to die, by the time the
voltage drops to 6 volts, the motor speed goes
to zero, flaps stop moving and gee whiz, the current
is still 7.5 amps.
Obviously in this simplistic case, current required
to extend flaps is never constant over full stroke
of the mechanisms. When you have the performance
curves for the motor, you can deduce behavior
at what ever voltage and load you wish bounded only
by speed bounded by potential damage to motor, torque
(current) bounded by risks of smoking wires/brushes,
and ability to move at all bounded by applied voltage
divided by internal resistance which yields a stall
current (or torque at which speed drops to zero).
Now, when picking a wire size to drive the motor,
any resistance EXTERNAL to the motor is in series
with INTERNAL resistance which serves to reduced
stall current. Suppose your wiring resistance reduces
14v stall current from 48 amps down to 43 amps. Just
draw in a new line (yellow) to account for the motor's
'new' loop resistance. You can draw any number of
additional lines parallel to the 14v curve to predict
performance at the full range of applied voltages
as described above.
Want to know how your installation particulars
influence motor performance? Get the motor performance
curves at any voltage, get out your pencil and straight
edge, and plot it out.
Understand too that the efficiency/power curves for
EACH voltage/loop resistance combination will need
recalculation.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flap motor draw for Rv-7A |
At 11:17 AM 3/12/2010, you wrote:
>Anyone know how many amps the flap motor draws on an RV-7A? I don't
>see it listed on the motor itself or on any of the documentation
>I've got and Van's doesn't know offhand either. I was going to use
>a 10A fuse and 14AWG wire (total wire run of about 15 feet) which
>seems very conservative, but I'd still like to know what the
>amperage draw is so I can calculate the total "worst-case peak"
>amperage that my alternator & battery will need to produce. Thanks.
As described in the posting of a few minutes ago,
wire size increases total loop resistance. This
has an easily predicted effect of reducing
stall current (translates to slow acceleration
of motor) and reduces speed of the motor.
At the same time, huge variability of voltage,
air loads and wiring resistance had have
MEASURABLE effects that may not even be
noticed by the pilot. How often do you check
flap travel times with a stop-watch?
Knowing the worst-case peak values are useful
only to the extent that you don't nuisance trip
your circuit protection. Using fuses to protect
a PM DC motor suggests some consideration for
weakening a fuse with repeated but infrequent
inrush values on the order of 30-50 amps . . . but
light guage wire goes a long way toward mitigating
that effect. Keeping voltage drop low improves on
motor performance but exacerbates inrush effects.
The 10A fuse and 14AWG wire is as good as any for
some reasons . . . upsizing to a 15A fuse is
good for other reasons. But one fellow talks
about pretty small wire and fuse . . . The motor
probably draws very low average current. Small
wire mitigates inrush. If this particular motor
seems sluggish during some portion of flap extension,
the pilot has no measured/considered reason to
attribute the effect to really high air loads,
small wire, undersized motor, or some combination
of those.
In the final analysis, it comes down to perceptions.
If it's been "doing the job" for some period of
time with no nuisance trips . . . well, it's
hard to argue with success! Doing what ever has
been installed in a few thousand RVs wouldn't
be a bad idea.
The point is, performance points for flap motors
in OBAM aircraft are all over the map. We could
spend a lot of time worrying about it . . . ultimately
fine tuning a decision that has no operational
benefits.
Bob . . .
________________________________________________________________________________
| Subject: | Patent on "warm up" for wigwag of HID |
| From: | "XeVision" <dblumel(at)XeVision.com> |
Our US patent was awarded Nov of 2009.
Vertical power has a license to use this patented technology in their units with
pulsing control capability.
Read this pdf news bulletin below.
http://www.xevision.com/pdf/Vertical...eVision_PR.pdf
We make 2 freestanding pulsing unit versions of our own, XePulse and XePulse II.
XePulse II is 1/3rd the size of our original XePulse (still available).
The original model (XePulse) has a terminal strip with 8 screw terminals. The new
XePulse II has a d-sub connector instead.
--------
LED still has a long way to go to compete with HID as a landing light. This is
true in terms of total lumens and reach (distance).
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290170#290170
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flap motor draw for Rv-7A |
Some private emails on the flap motor thing
have prompted some further expansion on the
topic of powering and sizing motors . . .
Anyone know how many amps the flap motor draws on an RV-7A? I
don't see it listed on the motor itself or on any of the
documentation I've got and Van's doesn't know offhand either.
Up until now, we've only discussed the capabilities
and performance of DC motors as described in their
performance data. This discussion says NOTHING about
what the motor is expected to do as-installed in
the airplane.
Just because a motor has some particular nameplate
rating does not automatically set the operating point
as installed. Looking at the data plots I published
yesterday . . .
http://www.aeroelectric.com/Pictures/Curves/Speed-Torque-Current_Curve.jpg
. . . suppose your flap system extension from 0-10
degrees required only 4 oz in of torque from the
motor. During this portion of the stroke it would
draw about 2A and run at 6800 rpm. Assume from 10-
20 degrees, air loads are building on the panels
and the current averages 6 oz in. Now current rises
to about 2.5 amps and speed drops to 6600. From
20-30 degrees, the air loads are at max. Torque might
rise to 10 oz-in at end of stroke with the current
surging up to 3.5A
This may be typical of what an RV or many other
OBAM aircraft demand of their flap extension systems.
This does not amount to much power. Indeed if we
compare the effort required to extend flaps by hand
with a "Johnson Bar", the horsepower developed during
a 30 pound pull through a arc length of 2 feet over
say 10 seconds really isn't much. The motor's task
is no greater except that SOME flap systems may
incorporate some form of worm gear reduction which
can have an efficiency of 30% or worse.
But even then, the power needed to extend flaps
is small. A HP is 550 lb-ft of work per second.
Our 60 lb-ft in two seconds is only 30 lb-ft/second
or 1/20th HP. A really lousy mechanism efficiency
might push that up to 1/5th HP.
In the hypothetical extension scenario I cited
above, electrical power into the flap extension
system peaked just before the haulted at the
fully extended position. 3.5A x 14v = 49 watts.
49w / 746w/hp = 0.06 HP
If these numbers are in the same reality ball park
with the system in an RV, then it's easy to see
how motor ratings on the side of the motor can
be VERY misleading with respect to real performance
numbers. Van's has had no particular reason to
go get the real numbers. In the airframe/power-plant
integrator's world, detail of electrical system
performance become useful ONLY when things are not
working and some investigation is launched to fix
the problem. Even then, the investigators may come
out of the exercise only having UPsized some
obviously undersized component (motor, breaker,
attach hardware, etc) and may STILL be uninformed
as to the real numbers.
I hope this exchange has shed some light on the
difficulty of answering questions like the one
that started this thread. Unless somebody has
taken the time and tools to go measure the performance,
the answer's will always be shallow and tend toward
the conservative. Certainly, wiring and fusing the
flap motor cited in the data plots at say 10A and
wiring with commensurate wire will eliminate any
possibility of nuisance tripping.
But understand that just because there's a 10 or
15A breaker protecting your hangar-mates flap
circuits doesn't say diddly-doo about what that
system really demands in terms of electrical
energy.
A pretty sharp cookie once opined,
"If you want to know, measure! When you can measure what you are
speaking about, and express it in numbers, you know something
about it, but when you cannot measure it, your knowledge is of
a meager kind." - Lord Kelvin 1824-1907
So after all this 'discussion' we're still unable
to answer the original question. Anyone got an
RV and a data acquisition system who would be
will to gather some real flight test data?
Bob . . .
________________________________________________________________________________
| From: | RScott <rscott(at)cascadeaccess.com> |
| Subject: | Re: FW: Zoo Sign In Dumas, TX, North of Amarillo |
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flap motor draw for Rv-7A (Corrected) |
Some private emails on the flap motor thing
have prompted some further expansion on the
topic of powering and sizing motors . . .
Anyone know how many amps the flap motor draws on an RV-7A? I
don't see it listed on the motor itself or on any of the
documentation I've got and Van's doesn't know offhand either.
Up until now, we've only discussed the capabilities
and performance of DC motors as described in their
performance data. This discussion says NOTHING about
what the motor is expected to do as-installed in
the airplane.
Just because a motor has some particular nameplate
rating does not automatically set the operating point
as installed. Looking at the data plots I published
yesterday . . .
http://www.aeroelectric.com/Pictures/Curves/Speed-Torque-Current_Curve.jpg
. . . suppose your flap system extension from 0-10
degrees required only 4 oz in of torque from the
motor. During this portion of the stroke it would
draw about 2A and run at 6800 rpm. Assume from 10-
20 degrees, air loads are building on the panels
and the current averages 6 oz in. Now current rises
to about 2.5 amps and speed drops to 6600. From
20-30 degrees, the air loads are at max. Torque might
rise to 10 oz-in at end of stroke with the current
surging up to 3.5A
This may be typical of what an RV or many other
OBAM aircraft demand of their flap extension systems.
This does not amount to much power. Indeed if we
compare the effort required to extend flaps by hand
with a "Johnson Bar", the horsepower developed during
a 30 pound pull through a arc length of 2 feet over
say 10 seconds really isn't much. The motor's task
is no greater except that SOME flap systems may
incorporate some form of worm gear reduction which
can have an efficiency of 30% or worse.
But even then, the power needed to extend flaps
is small. A HP is 550 lb-ft of work per second.
Our 60 lb-ft in two seconds is only 30 lb-ft/second
or 1/20th HP. A really lousy mechanism efficiency
might push that up to 1/5th HP.
In the hypothetical extension scenario I cited
above, electrical power into the flap extension
system peaked just before the haulted at the
fully extended position. 3.5A x 14v = 49 watts.
49w / 746w/hp = 0.06 HP
If these numbers are in the same reality ball park
with the system in an RV, then it's easy to see
how motor ratings on the side of the motor can
be VERY misleading with respect to real performance
numbers. Van's has had no particular reason to
go get the real numbers. In the airframe/power-plant
integrator's world, detail of electrical system
performance become useful ONLY when things are not
working and some investigation is launched to fix
the problem. Even then, the investigators may come
out of the exercise only having UPsized some
obviously undersized component (motor, breaker,
attach hardware, etc) and may STILL be uninformed
as to the real numbers.
I hope this exchange has shed some light on the
difficulty of answering questions like the one
that started this thread. Unless somebody has
taken the time and tools to go measure the performance,
the answer's will always be shallow and tend toward
the conservative. Certainly, wiring and fusing the
flap motor cited in the data plots at something
like 10 A and commensurate wire sizing will eliminate any
possibility of nuisance tripping.
But understand that just because there's a 10 or
15A breaker protecting your hangar-mates flap
circuit doesn't say diddly-doo about what that
system really demands in terms of electrical
energy.
A pretty sharp cookie once opined,
"If you want to know, measure! When you can measure what you are
speaking about, and express it in numbers, you know something
about it, but when you cannot measure it, your knowledge is of
a meager kind." - Lord Kelvin 1824-1907
So after all this 'discussion' we're still unable
to answer the original question. Anyone got an
RV and a data acquisition system who would be
will to gather some real flight test data?
Bob . . .
________________________________________________________________________________
| From: | John Markey <markeypilot(at)yahoo.com> |
| Subject: | Downed EAA Plane |
EAAer Lands Safely on Interstate in New Mexico
By Patrick Panzera
=C2-
=C2-
Jon Finley with Subar-Sonic, his Quickie Q-2 that won the COPPERSTATE 2008
Best Alternative Engine award.
March 8, 2010 =94 A Quickie Q-2, owned and piloted by Jonathan (Jon)
Finley (EAA 394580), made an emergency landing Saturday morning, March 6, o
n Interstate Highway 25, parallel to Mid Valley airpark (E98) in Los Lunas,
New Mexico. Jon=99s plane is powered with a direct-drive, Subaru aut
omobile conversion and was featured in the March 2009 issue of Experimenter
, EAA=99s homebuilder e-newsletter.
=C2-
[snip]
=C2-
By noon, Subar-Sonic was back in the hangar and still not willing to start.
Initial troubleshooting indicates that the problem may be due to a single
nut coming loose and getting into some electronics. =9CThe problem ap
pears to have been a nut in the cockpit (no, not this nut),=9D he jok
ed =9CLast time I looked at it was some 300 hours ago. Somewhere in t
hat timeframe it worked its way off the bolt and fell onto a printed circui
t board which seems to have defeated all of my built-in redundancy.
=C2-
=9CAt least that is the theory at the moment, and I can=99t fin
d anything else wrong. I won=99t know for sure for at least several d
ays but will let ya=99ll know when I know,=9D Jon told us.=0A
=0A=0A
________________________________________________________________________________
| Subject: | Re: Downed EAA Plane |
| From: | Dj Merrill <deej(at)deej.net> |
On 3/13/2010 2:26 PM, John Markey wrote:
> At least that is the theory at the moment, and I cant find anything
> else wrong. I wont know for sure for at least several days but will let
> yall know when I know, Jon told us.
Jon followed up later with:
Hi all,
I have confirmed the cause of my power failure last weekend. Long story
short - it was builder error. When you install a locknut on a bolt, you
MUST ensure that there is at least a thread or two coming all the way
thru the nut. If not, it will eventually vibrate free. I am guessing
that I did not look at these nuts after installation due to the
difficulty of seeing anything in this area. No excuse - get a mirror or
whatever is required and visually confirm this type of thing.
Longer story: To mount my EFI controller (computer in a metal box), I
mounted two bolts on the underside of my header tank, two holes in the
controller box, and then put locknuts on each of these bolts. One of
these nuts (and washer) came off the bolt and got down into the
electronics. I assume they bounced around in there for awhile before
finding the ideal location to cause a short which shut everything down.
I have changed my mounting method and now have nutplates inside this "box".
Please; learn from other's mistakes cause you don't have enough time to
make them all yourself!!
Jon Finley
________________________________________________________________________________
| From: | jimbean6(at)verizon.net |
| Subject: | Slowing down the trim |
We all know that the usual trim setup used in the RV's and others is very touchy.
Early in building my RV-8 I built and installed a 9 volt power supply intending
to power the headsets with it.
Foolish boy, that doesn't work.
Since the 9 volts was already there I tried it on the trim motor, leaving the trim
indicator supply at 14 volts.
Everything has been working fine with the trim just running slower, a good thing.
I realize that most people will not want to bother installing a separate 9 volt
supply but it does work.
For those interested the shack 5 amp regulator has a schematic and parts list on
the back of the package.
Contact me off-line for my trim schematic. It is in autocad format.
Jim Bean
jimbean6(at)verizon.net
RV-8 81110 80 hours.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Bob, Question on your WigWag flasher using a |
flasher relay
At 10:00 AM 3/12/2010, you wrote:
>
>Bob,
>
>On page 3.0 of your diagram on the single switch solution to a wig
>wag using the flasher relay.....
>
>You state that we can use a 15 amp breaker and 16awg wire for up
>to 2ea 100w lamps.
>
>Is this correct or a typo? Since when not in wigwag mode the full
>combined current will flow thru one 16awg wire, this seams to breaks
>some rules????
Good catch. Those drawings were done so long ago
that I don't now recall the reasoning behind
the suggestions. Obviously, not finely tuned.
I'll get them fixed in the not too distant future.
Thanks for the heads-up.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Downed EAA Plane |
| From: | Kevin Horton <khorton01(at)rogers.com> |
On 2010-03-13, at 15:05 , Dj Merrill wrote:
>
> On 3/13/2010 2:26 PM, John Markey wrote:
>
>> At least that is the theory at the moment, and I cant find anything
>> else wrong. I wont know for sure for at least several days but will let
>> yall know when I know, Jon told us.
>
> Jon followed up later with:
>
> Hi all,
>
> I have confirmed the cause of my power failure last weekend. Long story
> short - it was builder error. When you install a locknut on a bolt, you
> MUST ensure that there is at least a thread or two coming all the way
> thru the nut. If not, it will eventually vibrate free. I am guessing
> that I did not look at these nuts after installation due to the
> difficulty of seeing anything in this area. No excuse - get a mirror or
> whatever is required and visually confirm this type of thing.
>
> Longer story: To mount my EFI controller (computer in a metal box), I
> mounted two bolts on the underside of my header tank, two holes in the
> controller box, and then put locknuts on each of these bolts. One of
> these nuts (and washer) came off the bolt and got down into the
> electronics. I assume they bounced around in there for awhile before
> finding the ideal location to cause a short which shut everything down.
>
> I have changed my mounting method and now have nutplates inside this "box".
>
> Please; learn from other's mistakes cause you don't have enough time to
> make them all yourself!!
>
> Jon Finley
I'd also suggest that if a single short can lead to an engine failure that he should
review his system design. Even if he wishes to assume that this short cannot
physically occur, this occurrence suggests there are possibly other single
failures than can kill all power to critical components.
--
Kevin Horton
RV-8
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Downed EAA Plane |
Jon followed up later with:
Hi all,
I have confirmed the cause of my power failure last weekend. Long story
short - it was builder error. When you install a locknut on a bolt, you
MUST ensure that there is at least a thread or two coming all the way
thru the nut. If not, it will eventually vibrate free.
I have changed my mounting method and now have nutplates inside this "box".
Please; learn from other's mistakes cause you don't have enough time to
make them all yourself!!
I would like to follow up with the idea that
on a TC aircraft, there are NO plain nuts or
combinations of plain nuts and lockwashers used.
Non-locking, threaded fasteners are often supplied
on accessories from the outside world . . .
http://www.aeroelectric.com/Pictures/Contactors/Kilovac_EV200_contactor.jpg
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Mold-Captured_Terminals.jpg
http://aeroelectric.com/Pictures/Switches/Flap_Switch.jpg
Every time the system integrator picks up such
devices, there's supposed to be an evaluation of
risk due to "loose hardware". If the risks are
deemed great enough, non-locking fasteners will
be replaced with locking devices -or- doped with
Loc-tite on final assembly.
The tree-visible-threads rule has much more to do
with strength of the assembled fastener (indicates
that the screw is long enough) than with anti-
loosening. The same rule applies to all threaded
fasteners including the locking style nuts and
nutplates.
Where locking threads are not possible or practical,
consider still longer screws with a jamb-nut installed
on top of the structural nut. Further, a thread locker
that can be easily disassembled can go a long way
toward insuring joint integrity. Super-glue works
nice. It's thin and wicks into an already assembled
set of threads.
Bob . . .
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | Knuckolls Z-12 Power Grid Questions |
First for Bob K., I don't know what the experimental aircraft community
would do without all you've done to educate and guide us with your books,
classes, and ongoing advice on this forum. Thank you so much.
Hello AeroElectric gang,
My wife and I are building a Lancair Legacy and I've been working on wiring
diagrams to help with electrical system planning since they help capture the
layout of components, wiring, and connectors in the approximate topology of
the airplane.
Here is some background for our electrical system design goals and
requirements. For propulsion/engine reliability, we will fly with dual
magnetos though we will likely replace one with electronic ignition in the
future for improved efficiency and starting. We are designing for IFR
flight. We're planning on a Garmin G900X integrated avionics system. We
have an all electric air conditioning system (hot, humid Houston) that sits
behind the seats that steady state can pull about 50A continuous. To
support all this we have a 28V system with a primary 100A alternator and an
auxiliary 20A alternator.
For the power grid, we're using Knuckolls' Z-12 design (main alt, aux alt,
one battery) but without the Endurance Bus. In the event of an alternator
failure, I prefer to selectively load shed to reduce power demands based on
the current flight situation. We'll be ganging up two 12V Odyssey PC-680 17
AHr batteries to serve as one battery.
I have a couple questions I'd appreciate help with.
First, related to the E-Bus deletion, If we should find ourselves flying
along and the battery goes dead but the alternators are still working, I
want to still have power to the Battery Bus. So I've connected the
Main/System Bus to the Battery Bus with a diode in line to keep power from
flowing to the Main Bus when the battery contactor switch is off. Is this
the right way to provide this? Should this failure mode be protected for?
How likely is it with good maintenance practices that the battery would fail
in flight?
Second, with a carbon fiber/epoxy composite airframe, what are the options
for achieving a "common ground" for the system? Is it okay to have the
ground bus at the firewall, with a thru bolt to connect both sides, and then
run a jumper to a ground bus on the instrument panel where everything on the
panel is connected? Does this count as a common ground that will avoid
"electrical ground loops"?
Third, I'd like to have a battery ammeter to see it's charge and discharge
status. I've indicated a 100 mV/200A ammeter shunt. Should it be larger to
be able to see really high load cases like engine start?
I've attached a draft of our wiring diagram if that helps understand my
questions. Also, I'd appreciate hearing if anyone sees mistakes in it.
Thanks,
Valin Thorn
Lancair Legacy project
Houston, Texas USA
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
At 05:02 PM 3/13/2010, you wrote:
First for Bob K., I don't know what the experimental aircraft
community would do without all you've done to educate and guide us
with your books, classes, and ongoing advice on this forum. Thank you so much.
You're welcome. I'm pleased that you find the work useful!
Here is some background for our electrical system design goals and
requirements. dual magnetos. Garmin G900X.
All electric air conditioning at 50A continuous. 28V system. 100A
alternator. 20A aux alternator. Two 12V Odyssey PC-680 17 AHr
batteries in series.
First, related to the E-Bus deletion, If we should find ourselves
flying along and the battery goes dead . . .
So I've connected the Main/System Bus to the Battery Bus with a diode
in line to keep power from flowing to the Main Bus when the battery
contactor switch is off. Is this the right way to provide this?
Should this failure mode be protected for? How likely is it with
good maintenance practices that the battery would fail in flight?
Battery failure for devices favored with good
preventative maintenance is exceedingly rare.
We generally don't include battery failure as
a component of a failure mode effects analysis.
Second, with a carbon fiber/epoxy composite airframe, what are the
options for achieving a "common ground" for the system? Is it okay
to have the ground bus at the firewall, with a thru bolt to connect
both sides, and then run a jumper to a ground bus on the instrument
panel where everything on the panel is connected? Does this count as
a common ground that will avoid "electrical ground loops"?
Yes. See figure Z15 View A at:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z15K1.pdf
Third, I'd like to have a battery ammeter to see it's charge and
discharge status. I've indicated a 100 mV/200A ammeter
shunt. Should it be larger to be able to see really high load cases
like engine start?
Please don't do this. This was instrumentation of choice
for automobiles and some airplanes for years but needs
to go away. The readings presented are not useful for
managing an airplane in flight and are subject to a lot
of variability in interpretation. This configuration is
going to be removed from the 'Connection at Rev 13.
Active notification of Low Voltage, alternator load meters
and what ever voltmeters are built into your panel instrumentation
are more than adequate to the task.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
| From: | "user9253" <fran4sew(at)banyanol.com> |
Suggestions for Lancair Legacy IFR electrical schematic:
Replace the battery current shunt with a voltmeter.
The battery bus is on the wrong side of the firewall. It is not protected by a
fuse. If the battery bus circuit starts smoking, there is no way to shut it
off.
The avionics master contactor coil needs a diode like the other contactors. A
30amp automotive relay can replace that contactor. Mount it on the engine side
of the firewall so that it can isolate power in case of smoke in the cockpit.
> "If we should find ourselves flying along and the battery goes dead but the alternators
are still working."
You are more likely to win the lottery.
The wires feeding the Avionics bus are way too big.
When you are flying in the soup and the avionics master contactor circuit fails,
the glass panel will go dark. This could be a life threatening situation.
Here is how to prevent that:
Disconnect the diode from the battery bus and connect it to the avionics bus instead.
Disconnect the avionics contactor supply wire from the System bus and
connect it to the battery bus instead. Now there are two independent current
paths to the avionics bus.
The recommendation to shut off avionics while cranking the engine is based on an
old wives tale. Ask Bob. If you still want to shut off the avionics bus while
cranking, put a switch in series with the diode. But that introduces an unnecessary
failure point.
I hope this helps.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290280#290280
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flap motor draw for Rv-7A |
At 07:13 AM 3/14/2010, you wrote:
My measured current for my RV-& with the model 92345 motor was 2.0
Amps when at the stop, ie stalled. I discount the theory that when
the lube is cold that the current could be higher since the motor has
an over ride clutch which slips at the end of travel and if the
mechanical load was higher in the middle of travel then at the stops
the clutch should slip. Of course the starting current could be
higher but I doubt if it would be briefly more than 4 amp.. I have
been using a 5 amp fuse without problems.
Thanks for taking the time to do some real
measurements and share them with us. I'm having
trouble visualizing the electrical and mechanical
features of your flap extension system.
Normally, a motor that is powered up but not
turning will draw some value of current limited
only by its internal resistance. This would be
close to the data sheet stall current . . . on
the order of 30A or more. In this case, we would
expect the supply protection device to operate.
This is another reason why the proper adjustment
of limit switches is important.
I seem to recall that the RV flap actuator
was a ball-screw with free-wheel clutches
at each end of travel. If this is the case,
then the current you measured wasn't a "stall"
current in the conventional sense, but an
motor unloaded value that is a by-product
of the free-wheeling mechanisms.
Drag of the free-wheeling clutches at ends of
a ball screw are relatively insensitive to
temperature variation as you've guessed.
Were these measurements taken in flight
- airloads on the flaps during extend cycle?
Bob . . .
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
Thanks Bob and Joe.
I'm going to remove the ammeter for the battery and go with a tap for a
voltmeter. I'll add a fuse for the line to the battery bus. Since the
battery bus is going to power things like cabin lights, Hobbs meter, and
clock it seems like it is best to put it on the back of the instrument panel
near the switches, components it will power...? For future electronic
ignition I thought I'd run a tap directly from the battery. Agree line to
avionics bus was too big.
On the avionics contactor relay, I thought the diode was for if it was
switching inductive loads to prevent back EMF. Is a diode still recommended
for an avionics bus with resistive loads? Do I misunderstand the diodes
role here?
I hadn't heard that Bob K. doesn't see a need to isolate the avionics from
the main bus. I'd guess that with the power quality protection of modern
avionics that the transient from the engine starter motor is not an issue
these days. Still, with all that damn expensive electronics I'd rather not
test it at each engine start. It's also nice to bring it all up and down
with one switch. I agree that I can go with a lower capacity relay to
handle the job.
Thanks for pointing out that the avionics relay is a single point failure.
What do you guys think about getting one fault tolerant by having two
avionics bus relays/switches in parallel -- maybe one passing power from the
Battery Bus and one from the System Bus? Are their some other single point
failure modes that might need attention?
This is very helpful, thanks.
Valin
Valin Thorn
Lancair Legacy Project
Houston, Texas USA
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
At 02:25 PM 3/14/2010, you wrote:
>Thanks Bob and Joe.
>
>Im going to remove the ammeter for the battery
>and go with a tap for a voltmeter. Ill add a
>fuse for the line to the battery bus. Since the
>battery bus is going to power things like cabin
>lights, Hobbs meter, and clock it seems like it
>is best to put it on the back of the instrument
>panel near the switches, components it will power...?
Then it's not a battery bus but an always hot bus without
benefit of a battery contactor. The rule of thumb for always hot
wires is 6" or less in length and/or fused not greater that 7A
or breakered greater that 5A. This is why the battery busses
are shown on short feeders and have small fuses EXCEPT where
augmented by co-located relays.
We've got lots of battery busses in TC aircraft and many
do indeed have a goodly number of little bitty wires that
fan out to other places in the airplane.
> For future electronic ignition I thought Id
> run a tap directly from the battery. Agree line to avionics bus was too big.
Power it with its own fuse/breaker at the REAL
battery bus.
>
>On the avionics contactor relay, I thought the
>diode was for if it was switching inductive
>loads to prevent back EMF. Is a diode still
>recommended for an avionics bus with resistive
>loads? Do I misunderstand the diodes role here?
Diodes are check valves for electron flow in a host
of applications which include trapping off inductive
spikes from contactor coils and STEERING of power from
some source to some load while preventing back-flow of
power along the same path. A search of the website for
"diode" yields a collection of discussions on various
uses for diodes.
>
>I hadnt heard that Bob K. doesnt see a need to
>isolate the avionics from the main bus. Id
>guess that with the power quality protection of
>modern avionics that the transient from the
>engine starter motor is not an issue these
>days. Still, with all that damn expensive
>electronics Id rather not test it at each
>engine start. Its also nice to bring it all up
>and down with one switch. I agree that I can go
>with a lower capacity relay to handle the job.
Check out this article in particular:
http://www.aeroelectric.com/articles/avmaster.pdf
Go to the website at http://aeroelectric.com
and do a search on avionics + master + switch
for 15 hits on articles that discuss this topic.
>
>Thanks for pointing out that the avionics relay
>is a single point failure. What do you guys
>think about getting one fault tolerant by having
>two avionics bus relays/switches in parallel -
>maybe one passing power from the Battery Bus and
>one from the System Bus? Are their some other
>single point failure modes that might need attention?
Have you reviewed chapter 17 in the 'Connection
concerning system reliability along with the notes
that accompany the Z-figures? The philosophy and
features for failure tolerance in each example is
discussed.
The e-bus was crafted to provide a failure-tolerant
source for pieces of equipment particularly handy
for extended flight in spite of single failures of
hardware.
There is risk for "cherry picking" features of any
z-figure. Those things are all in there for a reason.
May I suggest you 'back up' and consider your z-figure
of choice (in this case Z-12) and explore how your
design goals differ from what's illustrated.
Bob . . .
________________________________________________________________________________
| From: | "Valin & Allyson Thorn" <thorn(at)starflight.aero> |
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
Thanks Bob,
I read your excellent Avionics Master Switch (AMS) article and re-read
AeroElectric Connection's chapter 17. Since we've only recently progressed
to the point in our Lancair Legacy project to where the electrical system
design details have to be decided, I've only recently fully engaged in the
subject. I was out of town on business when you came through Houston with
your class so my wife attended without me (but I'm doing the electrical...?)
So, I missed the previous debates, discussions on the AMS subject. I think
you've convinced me that we don't need an AMS.
I need to check on how you turn on a G900X integrated avionics system -- it
may be the equivalent of an AMS anyway... I'll check Monday.
With the addition of a 43 lb electric A/C system in our little Lancair
Legacy, we're working to trim some weight out. We've saved 17 lbs with an
MT prop vs. the Hartzell. If it were not for the weight concern I'd
probably opt for the dual alternator/dual battery system (or if I were going
dual electronic ignition). It seems that the Z-12 power grid is an
excellent, reliable architecture for us. I'm not yet convinced that the
Essential/Endurance Bus adds that much value. Though, if I found myself IFR
with electrical problems (aka panic:)) the idea of flipping a couple
switches to reconfigure would probably look like genius... It seems,
though, that it might improve reliability more for Z-12 to have dual
parallel battery contactors.
What do you think about that?
Thanks again,
Valin
BTW, I understand now what you mean by Battery Bus... It's by the battery
:) I'm reworking that architecture.
-----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
Sent: Sunday, March 14, 2010 5:33 PM
Subject: Re: AeroElectric-List: Re: Knuckolls Z-12 Power Grid Questions
At 02:25 PM 3/14/2010, you wrote:
>Thanks Bob and Joe.
>
>I'm going to remove the ammeter for the battery
>and go with a tap for a voltmeter. I'll add a
>fuse for the line to the battery bus. Since the
>battery bus is going to power things like cabin
>lights, Hobbs meter, and clock it seems like it
>is best to put it on the back of the instrument
>panel near the switches, components it will power...?
Then it's not a battery bus but an always hot bus without
benefit of a battery contactor. The rule of thumb for always hot
wires is 6" or less in length and/or fused not greater that 7A
or breakered greater that 5A. This is why the battery busses
are shown on short feeders and have small fuses EXCEPT where
augmented by co-located relays.
We've got lots of battery busses in TC aircraft and many
do indeed have a goodly number of little bitty wires that
fan out to other places in the airplane.
> For future electronic ignition I thought I'd
> run a tap directly from the battery. Agree line to avionics bus was too
big.
Power it with its own fuse/breaker at the REAL
battery bus.
>
>On the avionics contactor relay, I thought the
>diode was for if it was switching inductive
>loads to prevent back EMF. Is a diode still
>recommended for an avionics bus with resistive
>loads? Do I misunderstand the diodes role here?
Diodes are check valves for electron flow in a host
of applications which include trapping off inductive
spikes from contactor coils and STEERING of power from
some source to some load while preventing back-flow of
power along the same path. A search of the website for
"diode" yields a collection of discussions on various
uses for diodes.
>
>I hadn't heard that Bob K. doesn't see a need to
>isolate the avionics from the main bus. I'd
>guess that with the power quality protection of
>modern avionics that the transient from the
>engine starter motor is not an issue these
>days. Still, with all that damn expensive
>electronics I'd rather not test it at each
>engine start. It's also nice to bring it all up
>and down with one switch. I agree that I can go
>with a lower capacity relay to handle the job.
Check out this article in particular:
http://www.aeroelectric.com/articles/avmaster.pdf
Go to the website at http://aeroelectric.com
and do a search on avionics + master + switch
for 15 hits on articles that discuss this topic.
>
>Thanks for pointing out that the avionics relay
>is a single point failure. What do you guys
>think about getting one fault tolerant by having
>two avionics bus relays/switches in parallel --
>maybe one passing power from the Battery Bus and
>one from the System Bus? Are their some other
>single point failure modes that might need attention?
Have you reviewed chapter 17 in the 'Connection
concerning system reliability along with the notes
that accompany the Z-figures? The philosophy and
features for failure tolerance in each example is
discussed.
The e-bus was crafted to provide a failure-tolerant
source for pieces of equipment particularly handy
for extended flight in spite of single failures of
hardware.
There is risk for "cherry picking" features of any
z-figure. Those things are all in there for a reason.
May I suggest you 'back up' and consider your z-figure
of choice (in this case Z-12) and explore how your
design goals differ from what's illustrated.
Bob . . .
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
Hi Valin
I liked very much your wiring diagram, so when you finish re-doing it,
please post it again.
Thanks in advance
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Valin & Allyson Thorn
> Sent: segunda-feira, 15 de Mar=E7o de 2010 1:48
> To: aeroelectric-list(at)matronics.com
> Subject: RE: AeroElectric-List: Re: Knuckolls Z-12 Power Grid
Questions
>
>
>
> Thanks Bob,
>
> With the addition of a 43 lb electric A/C system in our little Lancair
> Legacy, we're working to trim some weight out. We've saved 17 lbs
with an
> MT prop vs. the Hartzell. If it were not for the weight concern I'd
> probably opt for the dual alternator/dual battery system (or if I were
going
> dual electronic ignition). It seems that the Z-12 power grid is an
> excellent, reliable architecture for us. I'm not yet convinced that
the
> Essential/Endurance Bus adds that much value. Though, if I found
myself
IFR
> with electrical problems (aka panic:)) the idea of flipping a couple
> switches to reconfigure would probably look like genius... It
seems,
> though, that it might improve reliability more for Z-12 to have dual
> parallel battery contactors.
>
> What do you think about that?
>
> Thanks again,
>
> Valin
>
> BTW, I understand now what you mean by Battery Bus... It's by the
battery
> :) I'm reworking that architecture.
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Flap motor draw for Rv-7A |
At 08:51 PM 3/14/2010, you wrote:
>You can surmise all you want about cold temps and related current
>draw, but there is a relationship. Don't think so, test at -5F and
>report. Otherwise, you're smply guessing.
Gently my friend. He DID come forward with some observed
current readings . . . and might be induced to go get some
more. Yeah, temperatures can have a huge effect on currents
because copper resistances go down and the grease (especially
on worm gears) gets stiff. But let's not scare him off. He
has hardware, test equipment, a demonstrated curiosity and
a willingness to share!
Bob . . .
________________________________________________________________________________
| From: | "Fred Stucklen" <wstucklen1(at)cox.net> |
| Subject: | Re: : Re: Flap motor draw for Rv-7A |
Interesting. I've tried 5 AMP fuses on three different RV's to date, and
all blew the fuses while
Trying to deploy the flaps during the first flight. Installing a 10 Amp
fuse always solved the problem.
Frederic Stucklen
RV-6A N925RV 2008 Hrs (Sold)
RV-6A N926RV 875 Hrs (Sold)
RV-7A N924RV 335 Hrs Flying
Time:
From:
"Robert L. Nuckolls, III"
Subject:
Re: Flap motor draw for Rv-7A
At 07:13 AM 3/14/2010, you wrote:
My measured current for my RV-& with the model 92345 motor was 2.0
Amps when at the stop, ie stalled. I discount the theory that when
the lube is cold that the current could be higher since the motor has
an over ride clutch which slips at the end of travel and if the
mechanical load was higher in the middle of travel then at the stops
the clutch should slip. Of course the starting current could be
higher but I doubt if it would be briefly more than 4 amp.. I have
been using a 5 amp fuse without problems.
Thanks for taking the time to do some real
measurements and share them with us. I'm having
trouble visualizing the electrical and mechanical
features of your flap extension system.
Normally, a motor that is powered up but not
turning will draw some value of current limited
only by its internal resistance. This would be
close to the data sheet stall current . . . on
the order of 30A or more. In this case, we would
expect the supply protection device to operate.
This is another reason why the proper adjustment
of limit switches is important.
I seem to recall that the RV flap actuator
was a ball-screw with free-wheel clutches
at each end of travel. If this is the case,
then the current you measured wasn't a "stall"
current in the conventional sense, but an
motor unloaded value that is a by-product
of the free-wheeling mechanisms.
Drag of the free-wheeling clutches at ends of
a ball screw are relatively insensitive to
temperature variation as you've guessed.
Were these measurements taken in flight
- airloads on the flaps during extend cycle?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | In search of the elegant solution (was: Z-12 considerations) |
At 08:47 PM 3/14/2010, you wrote:
>
>
>Thanks Bob,
>
>I was out of town on business when you came through Houston with
>your class so my wife attended without me (but I'm doing the electrical...?)
>So, I missed the previous debates, discussions on the AMS subject. I think
>you've convinced me that we don't need an AMS.
Yes, I recall meeting your wife and commiserating over
your absence!
>With the addition of a 43 lb electric A/C system in our little Lancair
>Legacy, we're working to trim some weight out. We've saved 17 lbs with an
>MT prop vs. the Hartzell. If it were not for the weight concern I'd
>probably opt for the dual alternator/dual battery system (or if I were going
>dual electronic ignition). It seems that the Z-12 power grid is an
>excellent, reliable architecture for us.
I agree.
>I'm not yet convinced that the Essential/Endurance Bus adds that much value.
Where does it DEVALUE? If you subscribe to the notion that
modern avionics have outlived the myths that promulgated
the AMS, then the task remaining is to craft a failure tolerant
system. The E-bus goes to that point. Further, it provides the
means by which electrical loads during an alternator-out configuration
can be predicted in advance. This is critical to an easily implemented
and well considered plan-B.
>Though, if I found myself IFR with electrical problems (aka panic:))
Why panic? That's the whole point of the plan-B exercise.
We KNOW that things are going to break. If one has plans
for every contingency, then where's the driver for panic?
>the idea of flipping a couple switches to reconfigure would probably
>look like genius... It seems, though, that it might improve
>reliability more for Z-12 to have dual parallel battery contactors.
>What do you think about that?
If that's what you want to do, by all means. But you'd probably
be flying one of a few dozen aircraft in the history of aviation
that was so equipped.
There are tens of thousands of airplanes that have successfully
launched and recovered into IMC with less reliable equipment,
heavier electrical loads and wired like a 1965 C-172.
Accidents having root cause in electrical system failure are
already exceedingly rare . . . and many if not most of those
could have been mitigated if not avoided by understanding
(well considered plan-B) and good preventative maintenance
(batteries, belts, attach brackets, etc) on the part of the
owner. Z-12 or any other z-figure offers a recipe for
success that has been filtered through years of
discussion and actual practice on thousands of airplanes.
Rather than stirring in new ingredients, it would seem
a better plan to deduce ways in which the architecture
fall short of mitigating demonstrable risks.
Then there's the matter of WHERE to put things and
HOW to wire them all up. Risks to your future in-flight
comfort will be driven more by the processes by which
you carry out the plan than the ingredients that go
into the plan. This idea is supported by the numerous
dark-n-stormy night stories we've studied here on the
list. We've also been privy to information from the
gleaned from the wreckage of several airplanes. NONE
of those events were forced by the failure of
single pieces of of properly installed hardware.
Bob . . .
________________________________________________________________________________
| From: | "Lapsley R. and Sandra E. Caldwell" <lrsecaldwell(at)earthlink.net> |
| Subject: | Re: Flap motor draw for Rv-7A |
I guess I did not make myself clear. I believe the clutch in the RV-7 is a friction
clutch. In other words the motor never stalls, but the clutch slips. Thus
max steady state current draw is set by the breakaway torque not any air loads.
Of course the current draw varies with temp, but I will still claim the peak current
will be the starting current. That too varies with temp. I would futher
claim that the peak starting current will occur if the flap is at the stop,
and you attempt to restart the flaps in that same direction, thus starting the
flap motor at max torque. However this would be a transient and mat not blow
the fuse. It does not blow my 5 amp fuse, admittedly at benign temps.
Since I do not have a environmental chamber at home I will be unable to meet your
request to measure at -5 deg.
Roger
From: "William Gill"<wgill10(at)comcast.net>
Subject: Re: AeroElectric-List: Re: Flap motor draw for Rv-7A
You can surmise all you want about cold temps and related current draw,
but there is a relationship. Don't think so, test at -5F and report.
Otherwise, you're smply guessing.
From: Lapsley R. and Sandra E. Caldwell
To:aeroelectric-list(at)matronics.com
Sent: Sunday, March 14, 2010 7:13 AM
Subject: AeroElectric-List: Re: Flap motor draw for Rv-7A
My measured current for my RV-& with the model 92345 motor was 2.0
Amps when at the stop, ie stalled. I discount the theory that when the
lube is cold that the current could be higher since the motor has an
over ride clutch which slips at the end of travel and if the mechanical
load was higher in the middle of travel then at the stops the clutch
should slip. Of course the starting current could be higher but I doubt
if it would be briefly more than 4 amp.. I have been using a 5 amp
fuse without problems.
Roger
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Running Big Battery Wire Through Firewall |
At 08:37 AM 3/10/2010, you wrote:
>
>David,
>
>I can tell you there is more than one way to skin a cat, but if you look
>at one of the gazillion Piper Cherokees out there, the cable runs from
>under the back seat along the left panel through the generally dry
>rotted grand-daddy grommet to the contactor mounted on the firewall.
>Size does matter but for 2 or 4 GA that won't make a difference. Good
>enough for Piper...
I don't think I've yet seen a commercial-off-the-shelf firewall
feedthru where the insulating material would have stood off
Jack Thermin's "puff the magic dragon" test. Electrically
and mechanically, these critters function as advertised.
The price is low and they seem adequately robust.
However, if one subscribes to the notion of protecting
firewall integrity with processes like . . .
http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html
then devices like . . .
Emacs!
and . . .
Emacs!
Are incompatible with the design goal cited in the
article. So if your design goals include attention
to details of fire-wall integrity, then perhaps
single fat-wires are best brought through grommets
with fire-shields and application of fire-putty
per Tony B's writings.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Lamar solid state contactors |
I've been in communication with folks at Lamar and
was updated on their plans and current offerings
for solid state contactors.
I'm going to be receiving an engineering data package
on the product line. They'll be sending me
some samples to play with as soon as I get a few
more boxes unpacked in M.L.
I've been both competitor and collaborator with
these folks (and their corporate ancestors) for
many years. In my experience they're both capable
and forthright in their dealings with the aircraft
industry.
If anyone on the List is waiting for ME to accomplish
anything specific in terms of evaluating the Smartswitch,
you may be wasting your time. After my conversation
this morning I judge that there is very low risk
for integrating the Lamar devices offered by
Aircraft Spruce into your project.
Bob . . .
________________________________________________________________________________
| Subject: | Re: : Re: Flap motor draw for Rv-7A |
| From: | thomas sargent <sarg314(at)gmail.com> |
Fred:
I have a 5 amp fuse on mine too. I haven't flown yet, so all the operation
of the flaps has been in the hangar, but I have not yet blown a fuse.
Do these things really use a clutch? I thought it was a screw that just
runs off the end of the threaded portion of the shaft at either end and the
n
re-engages when you reverse it. I don't know where I got that notion. I
could easily be wrong. I'm just point out that min/max flap extension may
not be high current events.
On Mon, Mar 15, 2010 at 4:29 AM, Fred Stucklen wrote:
> Interesting I=99ve tried 5 AMP fuses on three different
RV=99s to date, and
> all blew the fuses while
>
> Trying to deploy the flaps during the first flight. Installing a 10 Amp
> fuse always solved the problem
>
>
> *Frederic Stucklen*
>
--
Tom Sargent
________________________________________________________________________________
| Subject: | Re: Knuckolls Z-12 Power Grid Questions |
| From: | "user9253" <fran4sew(at)banyanol.com> |
> "On the avionics contactor relay, I thought the diode was for if it was switching
inductive loads to prevent back EMF. Is a diode still recommended for an
avionics bus with resistive loads? Do I misunderstand the diodes role here?"
A relay has two (or more) circuits. The coil is one circuit and the relay contacts
are in another circuit. The two circuits can be completely isolated from
each other. The purpose of a diode connected across a relay (or contactor) coil
is to protect the controlling switch from high voltage spark generated by
the relay coil when it is shut off by the switch. That high voltage has nothing
to do with the load on the relay contacts, whether that load is inductive or
resistive. In fact, a relay coil will produce a high voltage when it is shut
off, even if nothing at all is connected to the relay contacts. The bigger
the coil, the bigger the spark. A relay coil will not make as big of a spark
as a contactor coil. Connecting a diode across a relay coil will prolong the
life of the switch that controls it. The diode arrow should point towards positive.
> "Thanks for pointing out that the avionics relay is a single point failure. What
do you guys think about getting one fault tolerant by having two avionics
bus relays/switches in parallel - maybe one passing power from the Battery Bus
and one from the System Bus?"
Yes, that will work. What you are proposing is similar to the E-Bus. And it is
similar to what I proposed in my previous post, although I might not have explained
it clearly. Even if you do use two relays, the diode must still be used
to prevent high current from flowing from the avionics bus (AKA E-Bus) to the
system bus.
> "I'm not yet convinced that the Essential/Endurance Bus adds that much value."
The important feature of an E-Bus is that is has two independent current paths.
It would be easy to turn your avionics bus into an E-Bus by adding the alternate
feed path from the battery bus and a diode to prevent back-feeding the system
bus.
> "It seems, though, that it might improve reliability more for Z-12 to have dual
parallel battery contactors."
Yes, that will work, but will cost more and weigh more than using a relay and diode
along with an E-Bus that will accomplish the same thing.
It can be satisfying to design one's own electrical system. However, there could
be failure modes that you might not be aware of. The big advantage of using
one of Bob's drawings is that they have been proven over time and scrutinized
by many eyes. Any bugs have been worked out. Your schematic looks great in
colors. After a couple of minor changes, it will be similar to Z-11.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290394#290394
Attachments:
http://forums.matronics.com//files/e_bus_106.jpg
________________________________________________________________________________
| Subject: | Continued: Preferred Method for Redundant Power Sources |
to Single Input
| From: | jon(at)finleyweb.net |
=0AHi Bob,=0A =0ARegarding this archive thread: [http://forums.matronics.c
om/viewtopic.php?p=272463#272463] http://forums.matronics.com/viewtopic.p
hp?p=272463#272463=0A =0AI am interested to know the answer to the final
question. It was also the first question that came into my head after readi
ng your response. I'm not sure whether or not the answer matters but suspec
t that knowing the answer will answer that question!! ;-) =0A =0AGordon
Smith wrote:=0A"In this case when the two always-on sources differ by a vol
t or two, for whatever reason, Do the sources provide power proportionally
to their voltage or will it be a 100% feed from the highest voltage source?
" =0A =0AThanks!=0A =0AJon Finley=0AN314JF - Q2 - Subaru EJ-22=0A[http://ww
w.finleyweb.net/Q2Subaru.aspx] http://www.finleyweb.net/Q2Subaru.aspx
________________________________________________________________________________
| From: | "Lapsley R. and Sandra E. Caldwell" <lrsecaldwell(at)earthlink.net> |
| Subject: | Re: AeroElectric-List Digest: 8 Msgs - 03/15/10 |
Fred
It would be interesting if you could remember if you could remember id
the position of the flaps about blowing the fuse was fully up or down.
Also keep in mind that there have been at least two versions of the Flap
drive mechanism.
As to the clutch, if you operate the flaps without the engine running
you can hear the flap clutch slip at the fully up or down position (if
you don have any limit switches installed).
Roger
On 3/16/2010 2:55 AM, AeroElectric-List Digest Server wrote:
> From: "Fred Stucklen"<wstucklen1(at)cox.net>
> Subject: AeroElectric-List: : Re: Flap motor draw for Rv-7A
>
> Interesting. I've tried 5 AMP fuses on three different RV's to date, and
> all blew the fuses while
>
> Trying to deploy the flaps during the first flight. Installing a 10 Amp
> fuse always solved the problem.
>
>
> Frederic Stucklen
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Continued: Preferred Method for Redundant Power |
Sources to Single Input
At 07:18 PM 3/15/2010, you wrote:
>Hi Bob,
>
>Regarding this archive
>thread:
><http://forums.matronics.com/viewtopic.php?p=272463#272463>http://forums.matronics.com/viewtopic.php?p=272463#272463
>
>I am interested to know the answer to the final question. It was
>also the first question that came into my head after reading your
>response. I'm not sure whether or not the answer matters but suspect
>that knowing the answer will answer that question!! ;-)
>
>Gordon Smith wrote:
>"In this case when the two always-on sources differ by a volt or
>two, for whatever reason, Do the sources provide power
>proportionally to their voltage or will it be a 100% feed from the
>highest voltage source?"
The two either-or sources feeding a pair of diodes
need differ by only a few hundred millvolts for the
HIGHER of the two to pick up all loads downstream
of the diodes.
Bob . . .
________________________________________________________________________________
| From: | John Grosse <grosseair(at)comcast.net> |
| Subject: | Re: Running Big Battery Wire Through Firewall |
I'm sorry, but I'm not understanding something. The devices below look
more secure to me than a wire through a hole in the firewall filled with
fire putty. I can see that the bolt could conduct heat from a fire, but
then so could a wire. The concept with these devices seems the same to
me as a bulkhead fitting for hydraulic lines which is apparently okay.
So could someone explain why these electrical fittings are incompatible
with firewall security.
Thanks.
John Grosse
Robert L. Nuckolls, III wrote:
> At 08:37 AM 3/10/2010, you wrote:
>>
>> David,
>>
>> I can tell you there is more than one way to skin a cat, but if you look
>> at one of the gazillion Piper Cherokees out there, the cable runs from
>> under the back seat along the left panel through the generally dry
>> rotted grand-daddy grommet to the contactor mounted on the firewall.
>> Size does matter but for 2 or 4 GA that won't make a difference. Good
>> enough for Piper...
>
> I don't think I've yet seen a commercial-off-the-shelf firewall
> feedthru where the insulating material would have stood off
> Jack Thermin's "puff the magic dragon" test. Electrically
> and mechanically, these critters function as advertised.
> The price is low and they seem adequately robust.
>
> However, if one subscribes to the notion of protecting
> firewall integrity with processes like . . .
>
> http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html
>
> then devices like . . .
February 25, 2010 - March 15, 2010
AeroElectric-Archive.digest.vol-jj