Today's Message Index:
----------------------
1. 12:27 AM - Odyssey % of charge ()
2. 04:53 AM - Re: Odyssey % of charge (Alex Peterson)
3. 10:06 AM - Softcomm C300 ANR Headset (Hoffmann D- Remscheid)
4. 11:43 AM - Re: Over-voltage event w/ IR alternator ()
5. 01:25 PM - Re: Re: Over-voltage event w/ IR alternator (Matt Prather)
6. 01:27 PM - Re: Strobe power supplies was Wiring issues (Randy & Linda Nelson)
7. 03:18 PM - Re: Re: Over-voltage event w/ IR alternator (Brian Lloyd)
8. 03:48 PM - Z13-8 how to energize standby contactor? (Scott)
9. 03:56 PM - Z31-B Ground power disconnect? (Scott)
10. 04:03 PM - Z-13/8 Bad if both alternators on at once? (Scott)
11. 04:03 PM - Low Voltage Warn on E-Bus instead of Main? (Scott)
12. 04:44 PM - Re: Re: Over-voltage event w/ IR alternator (Dan Brown)
13. 04:59 PM - Re: Re: Over-voltage event w/ IR alternator (Robert L. Nuckolls, III)
14. 05:28 PM - Re: Strobe power supplies was Wiring issues (Charlie Kuss)
15. 05:30 PM - Re: Re: Over-voltage event w/ IR alternator (Ken)
16. 10:46 PM - instrument wiring (Chris & Kellie Hand)
17. 10:50 PM - dimmer ckt from Van's (Chris & Kellie Hand)
Message 1
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| Subject: | Odyssey % of charge |
--> AeroElectric-List message posted by: <rparigor@suffolk.lib.ny.us>
If the charging system is not working does anyone have an approximate % of
remaining capacity versus voltage for a Odyssey PC680 or similar?
What is a safe lower voltage limit one can discharge a PC680 to and not
cause permanent battery damage?
Thx.
Ron Parigoris
Message 2
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| Subject: | Odyssey % of charge |
--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@earthlink.net>
> --> AeroElectric-List message posted by: <rparigor@suffolk.lib.ny.us>
>
> If the charging system is not working does anyone have an
> approximate % of remaining capacity versus voltage for a
> Odyssey PC680 or similar?
>
> What is a safe lower voltage limit one can discharge a PC680
> to and not cause permanent battery damage?
>
> Thx.
> Ron Parigoris
Go to their website, there is a complete pdf for downloading.
Alex Peterson
RV6-A N66AP 714 hours
Maple Grove, MN
Message 3
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| Subject: | Softcomm C300 ANR Headset |
--> AeroElectric-List message posted by: "Hoffmann D- Remscheid" <Hoffmann.RS@t-online.de>
Softcomm seems to have a new ANR headset concept avoiding the trouble with all
the cables dangling around in the cockpit with the C300 ANR. As far as I understand
it they use the bias voltage for the electret microphone for power recruitment
which is surely very elegant.
However I wonder whether that can be sufficient, as power requirements for active
compensation are not negligible in a noisy environment. Any differences in
intercoms behaviour with this respect? Anybody who has experiences (good or bad)?
Thanks in advance
Richard Hoffmann
MCR4S Germany
Message 4
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: <gmcjetpilot@yahoo.com>
Mr. Bob Lee
Congratulation you had an overvoltage. You saw
that it limited the voltage to 18 volts max. I
think your volt meter is off and it was likely more
like 17 volts, but that is what the ND alternators
do. Their secondary voltage control limit is either
16v or 17v on some models. Not sure about a
Ford alternator, but all I-VR alternators (really the
only ones made now a day) use similar IC chip
control in the VR and OV limit of 17v max.
Even though you had an overvoltage you had some
control and never exceeded 18 volts (17 volts?).
Thanks for an excellent factual description with
out sensational emotional and prejudicial
comments. Yes an I-VR can have an OV but not the
wild runaway that gets spread around like brown
stinky stuff. Although OV is rare in the first place,
this is typical overvoltage when it does happen.
Bob and some dislike the I-VR because there is one
transistor that controls the field. If that transistor
failed (single point failure) it could in THEORY cause
a high uncontrolled OV condition. NO one has proved
this has EVER happened as they say. By prove I
mean took a claimed runaway VR and determined the
cause was this single point failure. Its RARE indeed.
In practice the field transistor is bullet proof.
Cooling air adds to the reliability of that or any transistor.
Don't install a I-VR like a E-VR they are differnt by design.
That is my only point I have tried to make in a
year of fighting the anecdotal comments Bob and
other's make. NO OFFENSE TO BOB. I agree the
E-VR has MORE control or should say more DIRECT
control of the fundamental thing that controls
output, the field wire. THAT IS AN ADVANTAGE.
(SEE I SAID IT, BUT THAT does not make I-VR bad.)
However let's be real. I-VR are super reliable as
is. Failures are rare and tend to be LOW voltage
or NO voltage events. When there is a spike above
the normal set voltage its a controllable event
by adding load.
Example in point: F150 Ford truck, IF YOU HAVE a
pull-able CB in your FORD truck for the alternator
output (b-lead), you would just pull the CB if the
voltage was too high. Done deal. No need for extra
protection or crow bars.
HOWEVER I KNOW BOB'S philosophy that he likes
automatic control. OK that is cool. However that
comes at the expense of weight, complexity and
potential nuisance trips that can damage a good
alternator.
BOB contradicts himself, saying don't use an I-VR at all?
OK great advice, but a problem?
NO ONE makes cheap off the shelf E-VR alternators?
Why spend++$600 for B&C or GUT a perfectly good I-VR?
Bottom line, Lee's alternator not only indicated
the OV failure, which shows the value of using the
warning light, the voltage never exceeded 18v (I
think you volt gauge is off by a volt). WHAT IS
WRONG WITH THAT? Most avionics can take anywhere
from 10-30 volts all day with out fail and even a
spike up to 60v for very short durations.
HERE HERE Mr. Lee!!!!!
Well done. I am putting you in my email post HALL
OF FAME. I agree with all you points except point
6, your conclusion, but than its not that point 6
is incorrect. I can't fault anything you said. I
just don't think its necessarily a needed.
Of your 6 points I summit the following comments:
1) The alternator defaults to 18v (17v?) by
design and typical. It is also NOT
indicative of the claim that the field has
gone crazy. There is a fault and it has lost
some control, but it is NOT out of control.
2) One event does not make a case, but your
experience is typical. In the rare cases of
OV (anything over 14.5v).
3) Check list are great
4) Z-13 would but so would reach over and
pulling a CB on the B-lead. I am not sure
turning the IGN "signal" to tell the VR to
go to sleep will work every time. Bob says
he does not recommend I-VR at all any more
any way, so if you are a disciple of his
doctrine the solution is obvious. I have no
issue with that.
5) I think it is worth the risk of good debate.
6) I am glad for you all the best. What ever
makes you sleep at night. By the way Ford
alternators have a bad service history
according to the NHTSA (Nits-a) (National
Highway Traffic Safety Administration). ND
alternators are as prolific and have a
spotless record in regards to consumer
complain, service bulletins and recalls.
My points are:
a) use the warning light; it is a fault light
not just a no charge light. If you don't use
the warning light, have something to
indicate a charge fault (hi/lo volts).
b) Do not turn the alternator on and off under
load.
c) Wire it (the ND alternator Van sells) just
like I show below. Which is a copy of how it
works in the Suzuki Samurai it was designed
for with one addition for aircraft use, the
50-60 amp pull-able CB in the panel.
d) If you want an I-VR and an OV relay and crow
bar, that is fine but you would be better
off going to an external VR if you can't
live with the I-VR as is, which is Bob Lee's
conclusion. I can't fault you for that. DO
what makes you happy.
http://img116.imageshack.us/my.php?image=altwiring5cm.jpg
A modified Toyota diagram.
http://img110.imageshack.us/my.php?image=toyota7gf.jpg
Flame Suit on. BTW please actually read what I
wrote first. I said external VR's are better in
that you have direct access to the field wire. I
also said I agree with Bob N and Bob L and
understand the desire to either use an OV
module/relay on an I-VR or use an E-VR.
I AGREE. Back off.
The only point I need to make is OV events with I-
VR's are rare, which Bob Lee made for me. I also need
to point out the SO CALLED overvoltage event was a
NON EVENT. In a car or plane it does little to
nothing since most devices can live on 17volts (or
even 18 volts as Bob Lee said, which I think is a
little high). AT LEAST this event was well
document and valid case to evaluate and its impact
on aircraft operations. Obviously Mr. Lee in his
F150 could just pull over and CRASH LAND on the
shoulder of the road. In a plane pulling over and
parking on a cloud is not possible. However that
is what a battery is for.
Sincerely George Nomex flame suit on.
From: <bob@flyboybob.com>
Subject: Over-voltage event w/ IR alternator
Message posted by: <bob@flyboybob.com>
Yesterday morning on the way to church I noticed
the alternator idiot Light come on. A quick check
of the volt meter indicated 18 volts. I was
Driving my son's 1990 Ford F-150 with an IR
alternator. It took me about Thirty seconds to
figure out what to do. There was not enough time
left Before church to make a forced landing so I
kept flying. I started turning on anything
electrical to absorb the extra electrons that were
smashing the battery. When I remembered the off
road driving lights my son recently installed and
turned them on I was down to 13 volts. The
voltage would vary with RPM and as long as I kept
everything on and the RPM below 1500 I could keep
the voltage under 14 volts. As the truck
accelerated away from a stop and the transmission
was in lower gears the idiot light would come on
each time the voltage was above 16 volts which
happened around 2000 RPM. Once in high gear the
RPM would settle around 1200 and the voltage would
be around 13 volts.
In thirty years of driving I would guess that I
have had five or six alternator failures. This is
the first time it has been a high voltage failure.
All of the other times it has been low output
failures.
Conclusions:
1. some IR alternators out there will detect an
overvoltage event (turn on the idiot light) and
yet do nothing about it (continue to produce 18
volts).
2. one event does not make conclusive science
3. a check list for OV events would have solved
this problem quicker. I need a plan for low
frequency failures with simple solutions.
4. z-13 would have handled this problem in my
airplane as the main alternator would have tripped
the OV module; the low voltage tone in my
earphones would alert me to turn on the standby
alternator and flight would have continued to
destination.
5. what I learned from conclusions 1, 3, and 4
is worth the risk of starting another IR
alternator e-mail flood.
6. I'm glad I removed the IR regulator from my
plane's alternator And replaced it with an
external unit and OV module.
Just remember, everything I say could be wrong - or right?
Regards,
Bob Lee
KR2 N52BL
91% done only 63% to go!
---------------------------------
Brings words and photos together (easily) with
Message 5
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Hello George,
A couple of questions:
What causes the failed IR overvoltage event to max-out at 17V (or 18V)?
Is it loads and battery? Or is the field current limited somehow. It
seems that we discussed that a short between Vb and the field (through the
main transistor, or otherwise) would cause cause an OV event similar to
what was described - open loop output, controlled by RPM, and load - the
battery being the primary load. Mr Lee didn't mention whether he
experimented with eliminating loads, and revving the engine to a higher
RPM (I wouldn't have tried that on my daily driver). But it seems that
you are suggesting that even had he done that, 17V would have been the
peak voltage seen on the bus. Am I reading you right?
How long can we predict that we can leave a typical 17Ah AGM battery
connected to 17V, and have it act as a system filter? Is there any risk
of fire associated with long term (admittedly, unquantified) operation in
such a manner? Asked another way, what's the charge rate on the battery
when pumped to 17V? I suppose your suggestion to include a b-lead
disconnect of some sort (breaker, in your case) addresses this issue. As
long as the pilot registers that the bus voltage is significantly out of
limits.
Without intending to put words into Bob (Nuckolls)'s mouth, I believe he
has said that he can't recommend IR alternators in the context of
designing an electrical system with certificated-like behavior. Not an
all-out condemnation of these alternators as a whole. I believe he has,
on several occasions, recognized the advantages of these low-cost devices.
Regards,
Matt-
> --> AeroElectric-List message posted by: <gmcjetpilot@yahoo.com>
>
> Mr. Bob Lee
>
> Congratulation you had an overvoltage. You saw
> that it limited the voltage to 18 volts max. I
> think your volt meter is off and it was likely more
> like 17 volts, but that is what the ND alternators
> do. Their secondary voltage control limit is either
> 16v or 17v on some models. Not sure about a
> Ford alternator, but all I-VR alternators (really the
> only ones made now a day) use similar IC chip
> control in the VR and OV limit of 17v max.
>
> Even though you had an overvoltage you had some
> control and never exceeded 18 volts (17 volts?).
>
> Thanks for an excellent factual description with
> out sensational emotional and prejudicial
> comments. Yes an I-VR can have an OV but not the
> wild runaway that gets spread around like brown
> stinky stuff. Although OV is rare in the first place,
> this is typical overvoltage when it does happen.
>
> Bob and some dislike the I-VR because there is one
> transistor that controls the field. If that transistor
> failed (single point failure) it could in THEORY cause
> a high uncontrolled OV condition. NO one has proved
> this has EVER happened as they say. By prove I
> mean took a claimed runaway VR and determined the
> cause was this single point failure. Its RARE indeed.
>
> In practice the field transistor is bullet proof.
>
> Cooling air adds to the reliability of that or any transistor.
>
> Don't install a I-VR like a E-VR they are differnt by design.
>
> That is my only point I have tried to make in a
> year of fighting the anecdotal comments Bob and
> other's make. NO OFFENSE TO BOB. I agree the
> E-VR has MORE control or should say more DIRECT
> control of the fundamental thing that controls
> output, the field wire. THAT IS AN ADVANTAGE.
>
> (SEE I SAID IT, BUT THAT does not make I-VR bad.)
>
> However let's be real. I-VR are super reliable as
> is. Failures are rare and tend to be LOW voltage
> or NO voltage events. When there is a spike above
> the normal set voltage its a controllable event
> by adding load.
>
> Example in point: F150 Ford truck, IF YOU HAVE a
> pull-able CB in your FORD truck for the alternator
> output (b-lead), you would just pull the CB if the
> voltage was too high. Done deal. No need for extra
> protection or crow bars.
>
> HOWEVER I KNOW BOB'S philosophy that he likes
> automatic control. OK that is cool. However that
> comes at the expense of weight, complexity and
> potential nuisance trips that can damage a good
> alternator.
>
> BOB contradicts himself, saying don't use an I-VR at all?
>
> OK great advice, but a problem?
>
> NO ONE makes cheap off the shelf E-VR alternators?
>
> Why spend++$600 for B&C or GUT a perfectly good I-VR?
>
> Bottom line, Lee's alternator not only indicated
> the OV failure, which shows the value of using the
> warning light, the voltage never exceeded 18v (I
> think you volt gauge is off by a volt). WHAT IS
> WRONG WITH THAT? Most avionics can take anywhere
> from 10-30 volts all day with out fail and even a
> spike up to 60v for very short durations.
>
> HERE HERE Mr. Lee!!!!!
>
> Well done. I am putting you in my email post HALL
> OF FAME. I agree with all you points except point
> 6, your conclusion, but than its not that point 6
> is incorrect. I can't fault anything you said. I
> just don't think its necessarily a needed.
>
> Of your 6 points I summit the following comments:
>
> 1) The alternator defaults to 18v (17v?) by
> design and typical. It is also NOT
> indicative of the claim that the field has
> gone crazy. There is a fault and it has lost
> some control, but it is NOT out of control.
>
> 2) One event does not make a case, but your
> experience is typical. In the rare cases of
> OV (anything over 14.5v).
>
>
> 3) Check list are great
>
>
> 4) Z-13 would but so would reach over and
> pulling a CB on the B-lead. I am not sure
> turning the IGN "signal" to tell the VR to
> go to sleep will work every time. Bob says
> he does not recommend I-VR at all any more
> any way, so if you are a disciple of his
> doctrine the solution is obvious. I have no
> issue with that.
>
>
> 5) I think it is worth the risk of good debate.
>
>
> 6) I am glad for you all the best. What ever
> makes you sleep at night. By the way Ford
> alternators have a bad service history
> according to the NHTSA (Nits-a) (National
> Highway Traffic Safety Administration). ND
> alternators are as prolific and have a
> spotless record in regards to consumer
> complain, service bulletins and recalls.
>
>
> My points are:
>
>
> a) use the warning light; it is a fault light
> not just a no charge light. If you don't use
> the warning light, have something to
> indicate a charge fault (hi/lo volts).
>
>
> b) Do not turn the alternator on and off under
> load.
>
>
> c) Wire it (the ND alternator Van sells) just
> like I show below. Which is a copy of how it
> works in the Suzuki Samurai it was designed
> for with one addition for aircraft use, the
> 50-60 amp pull-able CB in the panel.
>
> d) If you want an I-VR and an OV relay and crow
> bar, that is fine but you would be better
> off going to an external VR if you can't
> live with the I-VR as is, which is Bob Lee's
> conclusion. I can't fault you for that. DO
> what makes you happy.
>
>
> http://img116.imageshack.us/my.php?image=altwiring5cm.jpg
>
> A modified Toyota diagram.
>
> http://img110.imageshack.us/my.php?image=toyota7gf.jpg
>
>
> Flame Suit on. BTW please actually read what I
> wrote first. I said external VR's are better in
> that you have direct access to the field wire. I
> also said I agree with Bob N and Bob L and
> understand the desire to either use an OV
> module/relay on an I-VR or use an E-VR.
>
> I AGREE. Back off.
>
> The only point I need to make is OV events with I-
> VR's are rare, which Bob Lee made for me. I also need
> to point out the SO CALLED overvoltage event was a
> NON EVENT. In a car or plane it does little to
> nothing since most devices can live on 17volts (or
> even 18 volts as Bob Lee said, which I think is a
> little high). AT LEAST this event was well
> document and valid case to evaluate and its impact
> on aircraft operations. Obviously Mr. Lee in his
> F150 could just pull over and CRASH LAND on the
> shoulder of the road. In a plane pulling over and
> parking on a cloud is not possible. However that
> is what a battery is for.
>
> Sincerely George Nomex flame suit on.
>
>
> From: <bob@flyboybob.com>
> Subject: Over-voltage event w/ IR alternator
> Message posted by: <bob@flyboybob.com>
>
> Yesterday morning on the way to church I noticed
> the alternator idiot Light come on. A quick check
> of the volt meter indicated 18 volts. I was
> Driving my son's 1990 Ford F-150 with an IR
> alternator. It took me about Thirty seconds to
> figure out what to do. There was not enough time
> left Before church to make a forced landing so I
> kept flying. I started turning on anything
> electrical to absorb the extra electrons that were
> smashing the battery. When I remembered the off
> road driving lights my son recently installed and
> turned them on I was down to 13 volts. The
> voltage would vary with RPM and as long as I kept
> everything on and the RPM below 1500 I could keep
> the voltage under 14 volts. As the truck
> accelerated away from a stop and the transmission
> was in lower gears the idiot light would come on
> each time the voltage was above 16 volts which
> happened around 2000 RPM. Once in high gear the
> RPM would settle around 1200 and the voltage would
> be around 13 volts.
>
> In thirty years of driving I would guess that I
> have had five or six alternator failures. This is
> the first time it has been a high voltage failure.
> All of the other times it has been low output
> failures.
>
> Conclusions:
>
>
> 1. some IR alternators out there will detect an
> overvoltage event (turn on the idiot light) and
> yet do nothing about it (continue to produce 18
> volts).
>
> 2. one event does not make conclusive science
>
> 3. a check list for OV events would have solved
> this problem quicker. I need a plan for low
> frequency failures with simple solutions.
>
> 4. z-13 would have handled this problem in my
> airplane as the main alternator would have tripped
> the OV module; the low voltage tone in my
> earphones would alert me to turn on the standby
> alternator and flight would have continued to
> destination.
>
> 5. what I learned from conclusions 1, 3, and 4
> is worth the risk of starting another IR
> alternator e-mail flood.
>
> 6. I'm glad I removed the IR regulator from my
> plane's alternator And replaced it with an
> external unit and OV module.
>
> Just remember, everything I say could be wrong - or right?
> Regards,
> Bob Lee
> KR2 N52BL
> 91% done only 63% to go!
>
>
> ---------------------------------
> Brings words and photos together (easily) with
>
>
Message 6
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| Subject: | Re: Strobe power supplies was Wiring issues |
--> AeroElectric-List message posted by: "Randy & Linda Nelson" <RLNelson-5@peoplepc.com>
Ok My power supply is Whelen A413a 7 amps Can use either 1,2,3,4 lights
are 25 +25 joules or 12 joules or 25 +12 any combination depending if
alternate or simultaneous. Any thoughts on the wiring? Or the dimmer
stuff? I would like to start wiring my panel but am waiting on these 2
issues. Thanks
-------Original Message-------
From: Charlie Kuss
Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues
--> AeroElectric-List message posted by: Charlie Kuss <chaztuna@adelphia
net>
You might want to consult your Whelen manual regarding using this
power pack for 3 or 4 strobe heads. What is your power supply model?
Most Whelen and Nova power supplies only supply rated power to HALF
the number of heads. Most units only supply half power when using
more than half the maximum number of strobe heads. My Nova 904 can
run up to 6 heads. However, this means that each capacitor must power
2 heads rather than 1. This cuts the charging time (and therefore the
power output) for each head, in half.
This could become an issue when your DAR makes his/her inspection.
Charlie Kuss
>--> AeroElectric-List message posted by: "rlnelson5" <rlnelson-5@peoplepc
com>
>
>Hello
> Redoing my lower dash panel.
>
> 1 I have a Whalen strobe powerpack that can handle either 1,2,3
> or 4 strobes. It is 14v 7a unit . I have 2 wingtip , 1 tail and 1
> red strobe/ beacon.
>
> My question is if I could use a [ 2-10 ?] switch to control this
> strobe power unit and have the red beacon turn on the middle switch
> position and then add the other 3 strobes at the top switch position?
> If that would not do it is there some other arrangment to do it?
>
>2 I have the B + C instrament lighting dimmer setup .
> I have Inst. lights, couple of post lights Radio lights ,Lower
> dash panel lights , and 2 over the shoulder lights. I have a cabin
> ovhd light as well.
>
> I am using Fiber light units on most instraments and on the lower
> dash. The lower dash units are a long fiber optic strip that has
> lettering on them to label the lower dash panel items.
>
> How should I handle this whole setup?
> I only have one dimmer pot .
>Do I need some type of rotary switch?
> Regular switches or wire the ovhd to a seperate switch? ? wire
> them all together?
>
>Any ideas would be helfull
>
> thanks l
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=3D11546#11546
>
>
Message 7
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
gmcjetpilot@yahoo.com wrote:
> Bob and some dislike the I-VR because there is one
> transistor that controls the field. If that transistor
> failed (single point failure) it could in THEORY cause
> a high uncontrolled OV condition. NO one has proved
> this has EVER happened as they say. By prove I
> mean took a claimed runaway VR and determined the
> cause was this single point failure. Its RARE indeed.
Failure of the pass transistor in internally regulated or externally
regulated alternators and generators is rare but it does happen. Bob is
working on an OV protection circuit for the Nanchang CJ6A for just this
reason. The pass transistor in the VR shorts and turns the generator on
hard. (Late-model transistorized regulator, not the old
electromechanical regulator.) In one case it caused the battery to catch
fire. In another case the battery exploded causing substantial damage to
the aircraft. This is a dangerous failure that can result in the
destruction of the aircraft in flight if it happens. It deserves attention.
> In practice the field transistor is bullet proof.
Uh, no, that is not quite true. It is a transistor. It can fail. And
when it fails, it can fail shorted leading to an OV situation.
> 1) The alternator defaults to 18v (17v?) by
> design and typical. It is also NOT
> indicative of the claim that the field has
> gone crazy.
Crazy? Not a lot of useful information in that description. If you mean
that the pass transistor has shorted and turned the field on hard
leading to runaway high-voltage output, then, yes, that is the problem.
> There is a fault and it has lost
> some control, but it is NOT out of control.
I happen to think you are wrong but humor me. This is easy enough to
figure out if you can get to the field winding. Throw a 'scope
(something we idiot technicians know how to use) on the field and look
for the field being turned on and off rapidly (PWM control). If it is
always on, the pass transistor in the VR is failed shorted.
> 2) One event does not make a case, but your
> experience is typical. In the rare cases of
> OV (anything over 14.5v).
If it happens once, it will happen again. They can fail and when they
do, they will do serious damage to the battery and possibly the avionics.
Transistors do fail. That they are inside or outside the body of the
alternator does not change this fact.
Brian Lloyd
brian-yak@lloyd.com
Message 8
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| Subject: | Z13-8 how to energize standby contactor? |
--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
I'm rebuilding the electrical system on my flying RV6a. Conventional Mags
but all electric panel, so leaning strongly toward the Z-13/8 configuration.
I have developed several questions, but I'll send them individually to try
to keep the list archive most useable.
On the A13-8 diagram, it shows the Aux Alt "master" contractor energized
from the main battery side. Is there any reason not to energize it from the
SD-8 alternator side? My assumption is that the SD-8 will always generate a
voltage since it's got permanent magnets so it wouldn't need the battery to
energize the field before it was able to kick it's own relay on. It should
be a fine point that wouldn't usually matter, but if somehow the main
battery went flat (I don't know, flying with the Nav lights on durring the
day and not noticing a failed main alt because the low volts light bulb was
burned out?) it seems like it'd be nice to be able to bootstrap the system
from the SD-8.
Thanks!
Scott.
Message 9
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| Subject: | Z31-B Ground power disconnect? |
--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
Reviewing the diagram of the "piper" style ground power plug in Z-31B it
appears that once external power is applied, the contactor would stay
energized forever (at least until the battery was killed) since the
engergizing current would flow backward through the contactor and through
the solenoid coil. Is there a key point I'm missing or is an interrupt
switch of some kind called for?
Thanks!
Message 10
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| Subject: | Z-13/8 Bad if both alternators on at once? |
--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
Would it be "bad" if the main alternator was still running and the standby
alternator were engaged? My assumption is that which ever alternator's
regulator had the higher set point would max itself out (assuming a high
enough load) and the other alternator would pick up the rest (or idle) with
no ill effect on the system overall. Is this true, or are there issues I'm
missing like dynamic circuit response causing some kind of feedback or the
smaller SD8 burning itself up? A related question: If the load is greater
than the SD-8 can support is there any consequence other than the battery
supplying the extra required current? For instance if I flip on the battery
master and run landing lights or pitot heat or something.
Thanks again!
Scott.
Message 11
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| Subject: | Low Voltage Warn on E-Bus instead of Main? |
--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
The Z13-8 diagram shows the low voltage warning light connected to the main
bus. It seems to me like connecting it to the E-bus would be slightly more
useful. In that configuration, it should illuminate if the main alt drops
offline UNTIL the standby alt is engaged. At that point it stop indicating
unless/until the load exceeded the output capabiliy of the SD-8 standby
alternator. In that way it would essentially act as a "battery discharge"
warning (with the inference that if the voltage is below alternator
operating range, then the battery is discharging -- if only through the low
voltage warning circuit!) BTW, what is the current draw of the Low Voltage
Warning circuit? I presume it's very small and driven mostly by the
light/LED used.
Does anyone see a problem with this configuration? Does it miss a design
consideration that motivated it's original placement?
Message 12
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: Dan Brown <dan@familybrown.org>
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
gmcjetpilot@yahoo.com wrote:
> Congratulation you had an overvoltage. You saw
> that it limited the voltage to 18 volts max. I
Since the range of the voltmeter in question only extended to 18 volts,
it doesn't seem that we can confidently say what the voltage was, only
that it was at least 18 volts (or at least whatever voltage causes the
instrument to register 18 volts). The accuracy of the gauge could be
determined easily enough by cross-checking using a DVM of known
accuracy, so long as it was connected to the same place that the panel
meter uses--but that's really a side issue. As the scenario was
described, the voltmeter was pegged at 18 volts--you can't say from that
that the resulting voltage was 18 max; it's more like 18 min.
- --
Dan Brown, KE6MKS, dan@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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Message 13
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 02:20 PM 2/14/2006 -0700, you wrote:
>--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
>
>Hello George,
>
>A couple of questions:
>
>What causes the failed IR overvoltage event to max-out at 17V (or 18V)?
>Is it loads and battery?
Yes, recall the power system dynamics article I started last
spring:
http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf
Starting on page 6 we explore the battery's ability to stand
of the output of a runaway alternator . . .
> Or is the field current limited somehow. It
>seems that we discussed that a short between Vb and the field (through the
>main transistor, or otherwise) would cause cause an OV event similar to
>what was described - open loop output, controlled by RPM, and load - the
>battery being the primary load. Mr Lee didn't mention whether he
>experimented with eliminating loads, and revving the engine to a higher
>RPM (I wouldn't have tried that on my daily driver). But it seems that
>you are suggesting that even had he done that, 17V would have been the
>peak voltage seen on the bus. Am I reading you right?
>
>How long can we predict that we can leave a typical 17Ah AGM battery
>connected to 17V, and have it act as a system filter?
Depends on the size of the battery, its construction and it's
station in service life. The newer the battery, and assuming it's
an RG battery, it will hold a 60A alternator to something under
20 volts for some period of time. I'd guess maybe a minute or
more.
> Is there any risk
>of fire associated with long term (admittedly, unquantified) operation in
>such a manner?
Yes but slight. Remember this Odyssey battery we got from a Lister
who had suffered an ov condition? See pictures at:
http://www.aeroelectric.com/Pictures/Battery/Odyssey_OV/Odyssey_OV_1.jpg
But the risk is non-existent if you have some form of
ov warning, if only a light. You have some period of
time from onset of ov condition until things start coming
unglued.
>Asked another way, what's the charge rate on the battery
>when pumped to 17V? I suppose your suggestion to include a b-lead
>disconnect of some sort (breaker, in your case) addresses this issue. As
>long as the pilot registers that the bus voltage is significantly out of
>limits.
>
>Without intending to put words into Bob (Nuckolls)'s mouth, I believe he
>has said that he can't recommend IR alternators in the context of
>designing an electrical system with certificated-like behavior. Not an
>all-out condemnation of these alternators as a whole. I believe he has,
>on several occasions, recognized the advantages of these low-cost devices.
Back in December, I posted this response:
>Bob,
>
>Any recent updates on the "internally regulated alternator"?
>
>I know that you were not recommending it's use on an "all electric
>airplane with dual electronic ignition", which is the configuration of the
>plane I am building.
Not at all. The modern internally regulated alternator
is a great piece of hardware that offers excellent value
over most 60's certified alternators flying today. Your
choice of alternators has nothing to do with whether or
not you have electronic ignition, EFIS, or any other
modern feature.
Depending on WHICH IR alternator you choose, you may not
have 100%, absolute control over it's output which
does not satisfy traditional design goals.
Further, depending on WHICH IR alternator you choose,
you may not be able to add a convenient form of
OV protection which is also a traditional design
goal.
Finally, depending on WHICH IR alternator you choose,
the act of turning it on and OFF at inopportune times
may damage the alternator's regulator.
Having offered this, there are thousands of OBAM
aircraft flying wherein the builder has not included
these points in satisfaction of his own design goals
either because he has considered them insignificant
or doesn't understand them well enough to make a
well considered decision. None-the-less, a vast
majority of these aircraft ARE flying trouble free.
However, from time to time, we're made aware of
installations where the builder wishes he had
considered and adopted the traditional design
goals. It's a small percentage to be sure . . .
but then catastrophic runaway failures in the
certified ships also constitutes a small percentage
of all failures.
Bottom line is that we will be able to offer a means
by which any internally regulated alternator can
be integrated into your airplane under the traditional
design goals. In the mean time, drive on with whatever
installation instructions come with your alternator
of choice knowing that modifying the system will be
easy and inexpensive at a later time. I've been trying
to get the next few pages of "Understanding Alternators"
http://www.aeroelectric.com/articles/alternators/UA/Alternators_1.html
published but things are really busy around here this
time of year.
---------------------------------------
I've been working on the "Understanding Alternators" article
and plan to combine it with the DC Power System Dynamics
article.
Bob . . .
Message 14
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| Subject: | Re: Strobe power supplies was Wiring issues |
Cc: aeroelectric-list@matronics.com
--> AeroElectric-List message posted by: Charlie Kuss <chaztuna@adelphia.net>
Nelson,
Did you get an installation manual with this power supply? I ask,
because the A413A is an obsolete model. It has been superceded by the
model HDACF. See
http://www.whelen.com/aviation/catalog/Power%20Supply%20Replacement.pdf
Whelen's installation manual can be found here
http://www.whelen.com/aviation/Avserman.pdf
This unit will not meet the current light requirements, as even in
alternating mode, it only supplies 25 joules. Current requirement is
for approximately 40 joules. Most newer Whelen or Nova units produce
42 joules of light energy.
Running 3 or more strobe heads simultaneously will reduce the output
to only 12.5 joules.
Can you email me an electronic copy of your manual, if you have one?
Charlie Kuss
>--> AeroElectric-List message posted by: "Randy & Linda Nelson"
><RLNelson-5@peoplepc.com>
>
>Ok My power supply is Whelen A413a 7 amps Can use either 1,2,3,4 lights
>are 25 +25 joules or 12 joules or 25 +12 any combination depending if
>alternate or simultaneous. Any thoughts on the wiring? Or the dimmer
>stuff? I would like to start wiring my panel but am waiting on these 2
>issues. Thanks
>
>-------Original Message-------
>
>From: Charlie Kuss
>Date: 02/13/06 08:05:16
>To: aeroelectric-list@matronics.com
>Subject: Re: AeroElectric-List: Strobe power supplies was Wiring issues
>
>--> AeroElectric-List message posted by: Charlie Kuss <chaztuna@adelphia
>net>
>
>You might want to consult your Whelen manual regarding using this
>power pack for 3 or 4 strobe heads. What is your power supply model?
>Most Whelen and Nova power supplies only supply rated power to HALF
>the number of heads. Most units only supply half power when using
>more than half the maximum number of strobe heads. My Nova 904 can
>run up to 6 heads. However, this means that each capacitor must power
>2 heads rather than 1. This cuts the charging time (and therefore the
>power output) for each head, in half.
> This could become an issue when your DAR makes his/her inspection.
>Charlie Kuss
>
> >--> AeroElectric-List message posted by: "rlnelson5" <rlnelson-5@peoplepc
>com>
> >
> >Hello
> > Redoing my lower dash panel.
> >
> > 1 I have a Whalen strobe powerpack that can handle either 1,2,3
> > or 4 strobes. It is 14v 7a unit . I have 2 wingtip , 1 tail and 1
> > red strobe/ beacon.
> >
> > My question is if I could use a [ 2-10 ?] switch to control this
> > strobe power unit and have the red beacon turn on the middle switch
> > position and then add the other 3 strobes at the top switch position?
> > If that would not do it is there some other arrangment to do it?
> >
> >2 I have the B + C instrament lighting dimmer setup .
> > I have Inst. lights, couple of post lights Radio lights ,Lower
> > dash panel lights , and 2 over the shoulder lights. I have a cabin
> > ovhd light as well.
> >
> > I am using Fiber light units on most instraments and on the lower
> > dash. The lower dash units are a long fiber optic strip that has
> > lettering on them to label the lower dash panel items.
> >
> > How should I handle this whole setup?
> > I only have one dimmer pot .
> >Do I need some type of rotary switch?
> > Regular switches or wire the ovhd to a seperate switch? ? wire
> > them all together?
> >
> >Any ideas would be helfull
> >
> > thanks l
> >
> >
> >
> >
> >Read this topic online here:
> >
> >http://forums.matronics.com/viewtopic.php?p=3D11546#11546
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
Message 15
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| Subject: | Re: Over-voltage event w/ IR alternator |
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
Exactly what I was thinking Dan.
Even though the idiot light came on, without further info or testing of
the alternator I see no reason to assume that there was secondary OV
protection operating in this example. Maybe it was, maybe it wasn't.
Ken
Dan Brown wrote:
>--> AeroElectric-List message posted by: Dan Brown <dan@familybrown.org>
>
>-----BEGIN PGP SIGNED MESSAGE-----
>Hash: SHA1
>
>gmcjetpilot@yahoo.com wrote:
>
>
>
>>Congratulation you had an overvoltage. You saw
>>that it limited the voltage to 18 volts max. I
>>
>>
>
> Since the range of the voltmeter in question only extended to 18 volts,
>it doesn't seem that we can confidently say what the voltage was, only
>that it was at least 18 volts (or at least whatever voltage causes the
>instrument to register 18 volts). The accuracy of the gauge could be
>determined easily enough by cross-checking using a DVM of known
>accuracy, so long as it was connected to the same place that the panel
>meter uses--but that's really a side issue. As the scenario was
>described, the voltmeter was pegged at 18 volts--you can't say from that
>that the resulting voltage was 18 max; it's more like 18 min.
>
>- --
>Dan Brown, KE6MKS, dan@familybrown.org
>
>
Message 16
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| Subject: | instrument wiring |
--> AeroElectric-List message posted by: "Chris & Kellie Hand" <ckhand@earthlink.net>
I'm working on installing wiring and panel stuff in my RV-6A. The Van's fuel gage
and ammeter installation instructions say to use 18 AWG wire for the power,
ground, and sensor wires on the fuel gages and for the power and ground wire
on the ammeter. I didn't read that until after wiring up with 22 AWG as I didn't
think the current draw was significant enough to warrant anything bigger
- based this on an estimate of ~0.4 amps max per instrument from reference material
I looked at (yes, I looked through several books but didn't read the instructions
that came with the instruments....).
Am I that far out on my load estimates? Anybody think 18 AWG is really necessary
for powering these instruments? I'm wiring these independently, not daisy
chaining them as shown in the Van's drawings.
Thanks for any feedback,
Chris Hand
RV-6A, finishing stages
Message 17
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| Subject: | dimmer ckt from Van's |
--> AeroElectric-List message posted by: "Chris & Kellie Hand" <ckhand@earthlink.net>
I hooked up my instrument lights to the Van's dimmer ckt I installed and powered
things up. Power distribution is working and I have battery voltage at the
+12V terminal screw on the dimmer board. Also show good ground on the dimmer
board's ground terminal screw. Potentiometer is working properly and connected
to the right terminals on the board.
Output I'm getting at the Load terminal on the dimmer board varies from 0 to about
6 mV rather than the expected 2.5 V up to battery voltage.
The dimmer ckt is new out of the box, but I bought it well over a year ago and
didn't test it prior to now. Has anybody experienced similar issues with the
Van's board, and are there any suggestions on how to fix it without having to
buy a new one?
If I give up on the dimmer ckt from Van's, I need to find something else with a
poteniometer/dimmer knob the same size or larger since I already have the current
one installed in the panel.
Thanks for any help or advice you can give me.
Chris Hand
RV-6A, finishing stages
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