AeroElectric-Archive.digest.vol-fv
July 04, 2006 - July 15, 2006
Your words for George are entirely correct, but you must understand
that he has been admonished many many times before and just continues
to believe that he is the one and only god of the alternator
universe. Don't waste your breath (or keyboarding). If you are
smart, just put a filter in your email program that just dumps his
stuff in the trash. Yes, there are some good things he has to say
(occasionally) but most of that is available elsewhere. It's just
not worth the effort.
Best Regards,
Steve
________________________________________________________________________
On Jul 4, 2006, at 5:43 AM, LarryRobertHelming wrote:
> Please give us all a break and favor by showing you are a gentleman
> and just walk away until you get uncover (if there is any) some
> real evidence.
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Re: Grand Rapids Technology EIS Scaling Factor and |
Offset...
In addition, AuxOff must be odd.
Dave Reel - RV8A
________________________________________________________________________________
| Subject: | Potter & Brumfield w23 switche/circuit breaker |
I have had my heart set on using lighted rocker switches, but am
leaning towards the Potter & Brumsfield w23 since it would simplify wiring
and dash space. Any good or bad experiences with them ?
Randy
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Alternator failure thoughts |
There has been a lot of heat of late in the great alternator debate
(GAB). I thought I would throw in some thoughts and experience I have
had.
I have seen a number of alternator failures on cars, boats, and
airplanes. Some were pretty simple, no-brainer failures and some were
"HOLY S--T" failures. I thought I would toss in here the ways I can
see alternators failing (and have failed) and then address the failures.
Here are the failure modes I have see so far (feel free to add to
this list):
1. Straight electrical failures:
a. regulator failed -- no output
b. brushes failed -- no output
c. output diode failure -- whine and reduced output
d. diode trio failure -- no output
e. regulator failed -- runaway output (destroys battery and anything
else attached to the bus)
2. Mechanical failures:
a. bearing failure -- armature chews up stator -- no output
b. broken mounting brackets -- no output
c. broken wires, usually field -- no output
3. Miscellaneous failures:
a. burned up stator -- overload -- no output
First thing to think about is what to do when the alternator fails.
If you are on this list it probably means you are building your
electrical system with an eye toward safely completing the flight
with the lights still burning in the panel. I have come to the
conclusion that alternator failure is something that demands a
landing ASAP. Why? Because I have experienced too many failed-bearing
failures. The alternator stops producing output so you tend to think
in terms of electrical failure and just keep on going. I wonder what
would happen if the bearing were to fail so completely that the
armature would jam against the stator or one of the bell housings.
Instant stoppage. Nothing good is going to come from that much mass
stopping suddenly. I can certainly imagine mounting ears and mounting
brackets snapping and bits of alternator taking the grand tour of
your cowling.
So, I hold that an alternator failure should require a "let's land
and check it out now" response unless you can tell for sure it is an
electrical-only failure. And I don't know of a good way to tell if it
is an electrical-only failure.
Now as to causes, some have come up with vibration as a potential
source of failure. I agree. Lycoming engines are not particularly
smooth (but can be made a lot smoother by balancing, matching
mixtures in all the cylinders, and doing a dynamic prop balance). I
see extra-beefy mounting hardware as a plus here. The other form of
imbalance is the armature rotating balance. If the armature is
balanced the instantaneous vibrational loads on the bearings will be
a LOT less. I would expect this to result in reduced incidence of
mechanical failure of alternator bearings.
Heat is another killer. Insufficient cooling can result in burned
stator windings and/or failure of the lubricant in the bearings
leading to bearing failure. It seems to me that ensuring excellent
cooling is very important too. Many alternators have external or
internal fans but since most alternators are mounted on the hot side
of the baffling the fan just circulates hot air through the
alternator. The alternator really needs its own source of cool air
from before it passes through the cylinders. I would probably try to
find a source of cooling air that won't be as likely to contain water
if you run through the rain. I can't imagine that circulating water
through the alternator is likely to improve its longevity.
Hopefully this will spark some discussion about installation
practices that may improve alternator longevity over and above
anything we can do electrically.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Gary" <gtays(at)sympatico.ca> |
| Subject: | wiring for Turn Cord. |
I have a used RC Allen Turn and Bank and Artificial Attitude indicator both
electric. There are 3 pins in the back I have no idea how to wire these. Any
advice would be great.
Thanks
________________________________________________________________________________
| From: | "Harold" <kayce33(at)earthlink.net> |
| Subject: | Re: Alternator failure. Info provided (B&C value |
reliability)
Gee George,
It surely would be nice to see your writings without personal
complaints. Surely you could couch your criticisms in non personal terms
and still get your point across. All you would have to say is I think
this way might be better and explain why...then you'd have a dialogue,
not a public row. This way all could benefit, and then we ill educated,
vis a vis electronics could pick and choose our approach. We may not
make the best pick, but at least we'd have the info. The facts are being
obscured amid your charges.
Have a happy 4th,
Harold
________________________________________________________________________________
| From: | "Steven DiNieri" <capsteve(at)adelphia.net> |
| Subject: | wiring for Turn Cord. |
Try aircraft spruce pn# CANNON PLUG MS3106A-10SL-3S
steve
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gary
Sent: Tuesday, July 04, 2006 11:08 AM
I have a used RC Allen Turn and Bank and Artificial Attitude indicator
both
electric. There are 3 pins in the back I have no idea how to wire these.
Any
advice would be great.
Thanks
--
--
________________________________________________________________________________
| Subject: | Re: Potter & Brumfield w23 switche/circuit breaker |
Sorry I intended to write w31, but had a brain fart.
Randy
----- Original Message -----
Sent: Tuesday, July 04, 2006 9:43 AM
> <brinker@cox-internet.com>
>
> I have had my heart set on using lighted rocker switches, but am
> leaning towards the Potter & Brumsfield w23 since it would simplify wiring
> and dash space. Any good or bad experiences with them ?
>
> Randy
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator failure thoughts |
Good post.
I would add I have had an alternator on a Excavator suddenly lock up due to
a bearing seize and it was on the opposite end from the belt. It was a
sealed ball bearing and the result was a burned up belt 2300 hours on the
unit. A different failure than the too tight belt bearing damage often seen.
I also agree immediate landing is called for.
Paul
----- Original Message -----
Sent: Tuesday, July 04, 2006 7:57 AM
>
> There has been a lot of heat of late in the great alternator debate
> (GAB). I thought I would throw in some thoughts and experience I have
> had.
>
> I have seen a number of alternator failures on cars, boats, and
> airplanes. Some were pretty simple, no-brainer failures and some were
> "HOLY S--T" failures. I thought I would toss in here the ways I can see
> alternators failing (and have failed) and then address the failures.
>
> Here are the failure modes I have see so far (feel free to add to this
> list):
>
> 1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output (destroys battery and anything else
> attached to the bus)
>
> 2. Mechanical failures:
>
> a. bearing failure -- armature chews up stator -- no output
> b. broken mounting brackets -- no output
> c. broken wires, usually field -- no output
>
> 3. Miscellaneous failures:
>
> a. burned up stator -- overload -- no output
>
> First thing to think about is what to do when the alternator fails. If
> you are on this list it probably means you are building your electrical
> system with an eye toward safely completing the flight with the lights
> still burning in the panel. I have come to the conclusion that alternator
> failure is something that demands a landing ASAP. Why? Because I have
> experienced too many failed-bearing failures. The alternator stops
> producing output so you tend to think in terms of electrical failure and
> just keep on going. I wonder what would happen if the bearing were to
> fail so completely that the armature would jam against the stator or one
> of the bell housings. Instant stoppage. Nothing good is going to come
> from that much mass stopping suddenly. I can certainly imagine mounting
> ears and mounting brackets snapping and bits of alternator taking the
> grand tour of your cowling.
>
> So, I hold that an alternator failure should require a "let's land and
> check it out now" response unless you can tell for sure it is an
> electrical-only failure. And I don't know of a good way to tell if it is
> an electrical-only failure.
>
> Now as to causes, some have come up with vibration as a potential source
> of failure. I agree. Lycoming engines are not particularly smooth (but
> can be made a lot smoother by balancing, matching mixtures in all the
> cylinders, and doing a dynamic prop balance). I see extra-beefy mounting
> hardware as a plus here. The other form of imbalance is the armature
> rotating balance. If the armature is balanced the instantaneous
> vibrational loads on the bearings will be a LOT less. I would expect this
> to result in reduced incidence of mechanical failure of alternator
> bearings.
>
> Heat is another killer. Insufficient cooling can result in burned stator
> windings and/or failure of the lubricant in the bearings leading to
> bearing failure. It seems to me that ensuring excellent cooling is very
> important too. Many alternators have external or internal fans but since
> most alternators are mounted on the hot side of the baffling the fan just
> circulates hot air through the alternator. The alternator really needs
> its own source of cool air from before it passes through the cylinders. I
> would probably try to find a source of cooling air that won't be as
> likely to contain water if you run through the rain. I can't imagine that
> circulating water through the alternator is likely to improve its
> longevity.
>
> Hopefully this will spark some discussion about installation practices
> that may improve alternator longevity over and above anything we can do
> electrically.
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | "Harold" <kayce33(at)earthlink.net> |
| Subject: | Re: Alternator failure. Info provided (B&C value |
reliability)
Larry,
I think your george filter idea is great, if everyone did that, that
would reduce the clutter from trying to answer him. This could be a
refreshing future without the BS from one on an ego trip.
Harold
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: wiring for Turn Cord. |
If it's wired like every other 3-pin connector'ed gyro I've
encountered, Pin A goes to bus, pin B goes to ground.
Bob . . .
>I have a used RC Allen Turn and Bank and Artificial Attitude indicator
>both electric. There are 3 pins in the back I have no idea how to wire
>these. Any advice would be great.
>
>
>Thanks
>
>
>-- incoming mail is certified Virus Free.
>Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
>snipped
>I have seen a number of alternator failures on cars, boats, and
>airplanes. Some were pretty simple, no-brainer failures and some were
>"HOLY S--T" failures. I thought I would toss in here the ways I can
>see alternators failing (and have failed) and then address the failures.
>
>Here are the failure modes I have see so far (feel free to add to
>this list):
>
>1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output (destroys battery and
> anything
>else attached to the bus)
snipped
Brian,
I'd like to expand on item C of the list above
Output diodes comprise the rectifier. (converts AC current to
DC) For the purposes of the alternators we use, the rectifier is
comprised of 6 diodes. These diodes can fail in two modes, open or
short. Failing open (diode blows apart) is the more common failure
mode. In this mode, each diode that fails will reduce the
alternator's output by 1/6th.
Diodes that fail shorted are more insidious. Often, the pilot will
not notice a decrease in performance. However, he/she will generally
notice an increase in noise (generally on the radios) This is because
1/6th of the alternator's output is now bleeding through as AC
current. The ship's electrical system is designed for DC current. The
one item which really can not tolerate AC current is the battery. Any
time an alternator fails, it is best to do a postmortem, to determine
the cause.
Shorted rectifier diodes which are not repaired promptly, will soon
destroy the battery's storage capacity. This damage to the battery
may not be noticed, without conducting a battery output test. This is
important if you subscribe to Bob N's ideas regarding battery only
emergency operations.
Charlie Kuss
________________________________________________________________________________
| From: | "Dale Ensing" <densing(at)carolina.rr.com> |
| Subject: | Re: Alternator failure thoughts |
Output diodes comprise the rectifier. (converts AC current to DC) For
the purposes of the alternators we use, the rectifier is comprised of 6
diodes. These diodes can fail in two modes, open or short. Failing open
(diode blows apart) is the more common failure mode. In this mode, each
diode that fails will reduce the alternator's output by 1/6th.
Charlie,
Does the reduce output show as lower voltage and/or reduced maximum
amps?
Dale Ensing
________________________________________________________________________________
| From: | "Jekyll" <rcitjh(at)aol.com> |
| Subject: | Re: Alternator failure. Info provided (B&C value reliability) |
George adds substantial value to this forum. Each reader must decide if George
is brash, rude, obnoxious or none-of-the-above. I know what to expect when I see
him chime in on anything dealing with alternators or VR's HOWEVER, I also know
that his entries have caused, and will always cause a greater discussion of
the issues than would be had without him. This provides us all with a greater
understanding.
Don't chase George away because he riles you. Welcome him because he instigates
the forum to greater depths of discussion and research.
Out of chaos comes opportunity, out of heated discourse comes understanding and
knowledge.
Jekyll
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=44789#44789
________________________________________________________________________________
| From: | Deems Davis <deemsdavis(at)cox.net> |
| Subject: | Re: Alternator failure. Info provided (B&C |
out of dissonance come noise
Jekyll wrote:
>
>George adds substantial value to this forum. Each reader must decide if George
is brash, rude, obnoxious or none-of-the-above. I know what to expect when I
see him chime in on anything dealing with alternators or VR's HOWEVER, I also
know that his entries have caused, and will always cause a greater discussion
of the issues than would be had without him. This provides us all with a greater
understanding.
>
>Don't chase George away because he riles you. Welcome him because he instigates
the forum to greater depths of discussion and research.
>
>Out of chaos comes opportunity, out of heated discourse comes understanding and
knowledge.
>
>Jekyll
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=44789#44789
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
At 02:02 PM 7/4/2006, you wrote:
>Output diodes comprise the rectifier. (converts AC current to
>DC) For the purposes of the alternators we use, the rectifier is
>comprised of 6 diodes. These diodes can fail in two modes, open or
>short. Failing open (diode blows apart) is the more common failure
>mode. In this mode, each diode that fails will reduce the
>alternator's output by 1/6th.
>Charlie,
>Does the reduce output show as lower voltage and/or reduced maximum amps?
>Dale Ensing
Dale,
The reduced output can show itself as both a reduction in voltage
and amperage. If the load on the electrical system is below the
crippled alternator's ability to produce power, you may not notice
any difference. Generally though, reduced charging voltage will be
noticed first. This is why Bob N says that a good voltmeter is more
important to have than an ammeter.
An analogy could be made to an aircraft's ability to climb. An
aircraft can only climb as long as the engine can produce power in
excess of what is needed to maintain level flight at a given altitude.
An alternator's ability to increase the system voltage (assuming we
had no voltage regulator to stop a voltage climb) is limited by it's
ability to produce current (amps) in excess of the load on the system.
Charlie Kuss
________________________________________________________________________________
| From: | Email List Photo Shares <pictures(at)matronics.com> |
| Subject: | [ Dave Thompson ] : New Email List Photo Share Available! |
A new Email List Photo Share is available:
Poster: Dave Thompson
Lists: AeroElectric-List,Zenith-List
Subject: Proposed Zenith 601XL Panel Layout
http://www.matronics.com/photoshare/dave.thompson@verizon.net.07.04.2006/index.html
----------------------------------------------------------
o Main Photo Share Index
http://www.matronics.com/photoshare
o Submitting a Photo Share
If you wish to submit a Photo Share of your own, please include the
following information along with your email message and files:
1) Email List or Lists that they are related to:
2) Your Full Name:
3) Your Email Address:
4) One line Subject description:
5) Multi-line, multi-paragraph description of topic:
6) One-line Description of each photo or file:
Email the information above and your files and photos to:
pictures(at)matronics.com
----------------------------------------------------------
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Alternator failure thoughts |
We've discussed rotation speed a number of times but I still used larger
pulleys to keep the speed more in line with what my alternators would
see in their oem application. Automotive demonstrated reliability means
nothing to me when we run a component faster, hotter, at higher load, or
in a tight cowl, compared to an automotive engine compartment. Bearings
generally run cooler and last longer at slower speeds and vibration
loads are lower. I also like short dedicated belts that don't flop
around as much as long belts driving several accessories that have to be
fairly tight. I don't trust any alternator bracket that is less than
about 3/16" steel or 1/8" if truly 3 way triangulated. I hadn't really
considered it necessary to land soon following a alternator failure as
while I've discovered poor bearings during the electrical repair
(usually not on the pulley end), I've never had a bearing as the direct
cause of the failure -- yet ;) Maybe time to rethink a bit!
Ken
Brian Lloyd wrote:
>
>
> There has been a lot of heat of late in the great alternator debate
> (GAB). I thought I would throw in some thoughts and experience I have
> had.
>
> I have seen a number of alternator failures on cars, boats, and
> airplanes. Some were pretty simple, no-brainer failures and some were
> "HOLY S--T" failures. I thought I would toss in here the ways I can
> see alternators failing (and have failed) and then address the failures.
>
> Here are the failure modes I have see so far (feel free to add to
> this list):
>
> 1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output (destroys battery and
> anything else attached to the bus)
>
> 2. Mechanical failures:
>
> a. bearing failure -- armature chews up stator -- no output
> b. broken mounting brackets -- no output
> c. broken wires, usually field -- no output
>
> 3. Miscellaneous failures:
>
> a. burned up stator -- overload -- no output
>
> First thing to think about is what to do when the alternator fails.
> If you are on this list it probably means you are building your
> electrical system with an eye toward safely completing the flight
> with the lights still burning in the panel. I have come to the
> conclusion that alternator failure is something that demands a
> landing ASAP. Why? Because I have experienced too many failed-bearing
> failures. The alternator stops producing output so you tend to think
> in terms of electrical failure and just keep on going. I wonder what
> would happen if the bearing were to fail so completely that the
> armature would jam against the stator or one of the bell housings.
> Instant stoppage. Nothing good is going to come from that much mass
> stopping suddenly. I can certainly imagine mounting ears and mounting
> brackets snapping and bits of alternator taking the grand tour of
> your cowling.
>
> So, I hold that an alternator failure should require a "let's land
> and check it out now" response unless you can tell for sure it is an
> electrical-only failure. And I don't know of a good way to tell if it
> is an electrical-only failure.
>
> Now as to causes, some have come up with vibration as a potential
> source of failure. I agree. Lycoming engines are not particularly
> smooth (but can be made a lot smoother by balancing, matching
> mixtures in all the cylinders, and doing a dynamic prop balance). I
> see extra-beefy mounting hardware as a plus here. The other form of
> imbalance is the armature rotating balance. If the armature is
> balanced the instantaneous vibrational loads on the bearings will be
> a LOT less. I would expect this to result in reduced incidence of
> mechanical failure of alternator bearings.
>
> Heat is another killer. Insufficient cooling can result in burned
> stator windings and/or failure of the lubricant in the bearings
> leading to bearing failure. It seems to me that ensuring excellent
> cooling is very important too. Many alternators have external or
> internal fans but since most alternators are mounted on the hot side
> of the baffling the fan just circulates hot air through the
> alternator. The alternator really needs its own source of cool air
> from before it passes through the cylinders. I would probably try to
> find a source of cooling air that won't be as likely to contain water
> if you run through the rain. I can't imagine that circulating water
> through the alternator is likely to improve its longevity.
>
> Hopefully this will spark some discussion about installation
> practices that may improve alternator longevity over and above
> anything we can do electrically.
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 4, 2006, at 1:07 PM, Charlie Kuss wrote:
>> c. output diode failure -- whine and reduced output
>>
>
> Brian,
> I'd like to expand on item C of the list above
>
> Output diodes comprise the rectifier. (converts AC current to DC)
> For the purposes of the alternators we use, the rectifier is
> comprised of 6 diodes. These diodes can fail in two modes, open or
> short. Failing open (diode blows apart) is the more common failure
> mode. In this mode, each diode that fails will reduce the
> alternator's output by 1/6th.
Actually, I am pretty sure it is still 1/3 of the output. (Warning:
technical BS follows.) Each diode is part of a full-wave bridge for
two of the three phases. Therefore when one diode opens you lose a
half-wave of output from two of the three phases. Since there are six
half-wave outputs, two from each of the three phases, you still lose
1/3 of your potential output.
And then there is the whole root mean square (RMS) thing. Without
doing the math I am going to guess that the loss of one diode (open)
is going to reduce the available power (amps probably) by 1/3. Ripple
will also be up substantially.
> Diodes that fail shorted are more insidious. Often, the pilot will
> not notice a decrease in performance. However, he/she will
> generally notice an increase in noise (generally on the radios)
> This is because 1/6th of the alternator's output is now bleeding
> through as AC current.
Well, actually it is not. With one diode shorted it will show up as a
dead short on two of the phases for half a wave. The current from the
affected phases will go through the good diode but return to the
winding through the shorted diode so two of the phases will see a
short through one diode drop. So for half a wave two of the phases
will be producing maximum current and dissipating it in the
resistance of those two stator windings. To the outside world it will
look like and ope diode (I think -- I am guessing here) but I suspect
that the affected phases of the stator will very quickly burn
themselves up unless the alternator has superb cooling.
> The ship's electrical system is designed for DC current. The one
> item which really can not tolerate AC current is the battery. Any
> time an alternator fails, it is best to do a postmortem, to
> determine the cause.
> Shorted rectifier diodes which are not repaired promptly, will
> soon destroy the battery's storage capacity. This damage to the
> battery may not be noticed, without conducting a battery output
> test. This is important if you subscribe to Bob N's ideas regarding
> battery only emergency operations.
I understand your logic Charlie but, as I indicated above, I don't
think it will work the way you have outlined.
But this was just an off-the-top-of-my-head analysis and very will
could be wrong.
> Charlie Kuss
>
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Paul's article on modifying ND and MI alternators |
Charlie Kuss forwarded to me Paul Messinger's article from Contact
magazine about modifying the Nippon Denso and Mitsubishi alternators
for external regulation. Good article. It says a lot more than I
could. I recommend snagging a copy and reading it if you are
interested in possibly modifying your alternator for external
regulation.
Actually, you should snag a copy so you can understand how your ND
and/or MI alternators work. It has an interesting discussion about
bearings and slip-ring failure. Good reading.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 4, 2006, at 3:16 PM, Charlie Kuss wrote:
> At 02:02 PM 7/4/2006, you wrote:
>> Output diodes comprise the rectifier. (converts AC current to DC)
>> For the purposes of the alternators we use, the rectifier is
>> comprised of 6 diodes. These diodes can fail in two modes, open or
>> short. Failing open (diode blows apart) is the more common
>> failure mode. In this mode, each diode that fails will reduce the
>> alternator's output by 1/6th.
>> Charlie,
>
>> Does the reduce output show as lower voltage and/or reduced
>> maximum amps?
>> Dale Ensing
>
> Dale,
> The reduced output can show itself as both a reduction in voltage
> and amperage.
The peak voltage available will remain the same as each winding of
the stator is capable of that peak voltage. But the ripple will be up
and the available current will be down. With one diode gone (open) I
would bet that a 60A alternator becomes a 40A alternator. If one
diode shorts the alternator becomes a 40A alternator and then shortly
thereafter a 20A alternator as two of the windings in the stator burn
out.
> If the load on the electrical system is below the crippled
> alternator's ability to produce power, you may not notice any
> difference.
I agree with that but you will start to hear one heck of an
alternator whine.
> Generally though, reduced charging voltage will be noticed first.
> This is why Bob N says that a good voltmeter is more important to
> have than an ammeter.
But the VR is going to increase the field current to keep the voltage
where it is supposed to be. As long as you are drawing less than 1/3
of the alternator's rated output you won't notice anything but the
whine. What will be reduced is the charging current.
> An analogy could be made to an aircraft's ability to climb. An
> aircraft can only climb as long as the engine can produce power in
> excess of what is needed to maintain level flight at a given altitude.
> An alternator's ability to increase the system voltage (assuming
> we had no voltage regulator to stop a voltage climb) is limited by
> it's ability to produce current (amps) in excess of the load on the
> system.
True.
>
> Charlie Kuss
>
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Paul's article on modifying ND and MI alternators |
Thanks; I will be updating the article as a PDF with current info and part
numbers etc as needed. Need a couple of weeks to complete but it will not be
limited to the mag article for photo size and resolution etc.
Paul
----- Original Message -----
Sent: Tuesday, July 04, 2006 2:13 PM
alternators
>
> Charlie Kuss forwarded to me Paul Messinger's article from Contact
> magazine about modifying the Nippon Denso and Mitsubishi alternators for
> external regulation. Good article. It says a lot more than I could. I
> recommend snagging a copy and reading it if you are interested in
> possibly modifying your alternator for external regulation.
>
> Actually, you should snag a copy so you can understand how your ND and/or
> MI alternators work. It has an interesting discussion about bearings and
> slip-ring failure. Good reading.
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | "John W. Cox" <johnwcox(at)pacificnw.com> |
| Subject: | Re: Alternator failure. Info provided (B&C |
I have been shoveling so long on this subject, I know there must be a
pony here with the aeroelectric group discussion somewhere. The GMCpilot
filter is a most interesting point to ponder. Happy 4th.
John Cox
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Deems
Davis
Sent: Tuesday, July 04, 2006 12:18 PM
(B&C
-->
out of dissonance come noise
Jekyll wrote:
>
>George adds substantial value to this forum. Each reader must decide if
George is brash, rude, obnoxious or none-of-the-above. I know what to
expect when I see him chime in on anything dealing with alternators or
VR's HOWEVER, I also know that his entries have caused, and will always
cause a greater discussion of the issues than would be had without him.
This provides us all with a greater understanding.
>
>Don't chase George away because he riles you. Welcome him because he
instigates the forum to greater depths of discussion and research.
>
>Out of chaos comes opportunity, out of heated discourse comes
understanding and knowledge.
>
>Jekyll
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=44789#44789
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
>On Jul 4, 2006, at 1:07 PM, Charlie Kuss wrote:
>
>>> c. output diode failure -- whine and reduced output
>
>>
>>Brian,
>> I'd like to expand on item C of the list above
>>
>>Output diodes comprise the rectifier. (converts AC current to DC)
>>For the purposes of the alternators we use, the rectifier is
>>comprised of 6 diodes. These diodes can fail in two modes, open or
>>short. Failing open (diode blows apart) is the more common failure
>>mode. In this mode, each diode that fails will reduce the
>>alternator's output by 1/6th.
>
>Actually, I am pretty sure it is still 1/3 of the output. (Warning:
>technical BS follows.) Each diode is part of a full-wave bridge for
>two of the three phases. Therefore when one diode opens you lose a
>half-wave of output from two of the three phases. Since there are six
>half-wave outputs, two from each of the three phases, you still lose
>1/3 of your potential output.
Brian,
Your suggestion of a 33% loss of output is closer to real world
losses. I have tested charging systems which showed a 20 to 35% loss
of output. Tear down of the alternator later for repair showed that
one diode had failed in the rectifier.
>And then there is the whole root mean square (RMS) thing. Without
>doing the math I am going to guess that the loss of one diode (open)
>is going to reduce the available power (amps probably) by 1/3. Ripple
>will also be up substantially.
>
>> snipped
>
>Well, actually it is not. With one diode shorted it will show up as a
>dead short on two of the phases for half a wave. The current from the
>affected phases will go through the good diode but return to the
>winding through the shorted diode so two of the phases will see a
>short through one diode drop. So for half a wave two of the phases
>will be producing maximum current and dissipating it in the
>resistance of those two stator windings. To the outside world it will
>look like and ope diode (I think -- I am guessing here) but I suspect
>that the affected phases of the stator will very quickly burn
>themselves up unless the alternator has superb cooling.
I've tested alternators which would meet the output spec (for a
limited time) Then one (or more) of the rectifier diodes would
overheat and short. My point here is that not all failures are "hard"
failures. When diagnosing a charging system you can't always rely on
what "theory" says should happen. :-(
>>The ship's electrical system is designed for DC current. The one
>>item which really can not tolerate AC current is the battery. Any
>>time an alternator fails, it is best to do a postmortem, to
>>determine the cause.
>> Shorted rectifier diodes which are not repaired promptly, will
>>soon destroy the battery's storage capacity. This damage to the
>>battery may not be noticed, without conducting a battery output
>>test. This is important if you subscribe to Bob N's ideas regarding
>>battery only emergency operations.
>
>I understand your logic Charlie but, as I indicated above, I don't
>think it will work the way you have outlined.
>
>But this was just an off-the-top-of-my-head analysis and very will
>could be wrong.
>
>Brian Lloyd 361 Catterline Way
My experience here is anecdotal, as it simply relates to what I've
seen in my experiences.
Charlie
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
>>>snipped
>>
>>>Does the reduce output show as lower voltage and/or reduced
>>>maximum amps?
>>>Dale Ensing
>>
>>Dale,
>> The reduced output can show itself as both a reduction in voltage
>>and amperage.
>
>The peak voltage available will remain the same as each winding of
>the stator is capable of that peak voltage. But the ripple will be up
>and the available current will be down. With one diode gone (open) I
>would bet that a 60A alternator becomes a 40A alternator. If one
>diode shorts the alternator becomes a 40A alternator and then shortly
>thereafter a 20A alternator as two of the windings in the stator burn
>out.
>
>>If the load on the electrical system is below the crippled
>>alternator's ability to produce power, you may not notice any
>>difference.
>
>I agree with that but you will start to hear one heck of an
>alternator whine.
>
>>Generally though, reduced charging voltage will be noticed first.
>>This is why Bob N says that a good voltmeter is more important to
>>have than an ammeter.
>
>But the VR is going to increase the field current to keep the voltage
>where it is supposed to be. As long as you are drawing less than 1/3
>of the alternator's rated output you won't notice anything but the
>whine. What will be reduced is the charging current.
>
>>An analogy could be made to an aircraft's ability to climb. An
>>aircraft can only climb as long as the engine can produce power in
>>excess of what is needed to maintain level flight at a given altitude.
>> An alternator's ability to increase the system voltage (assuming
>>we had no voltage regulator to stop a voltage climb) is limited by
>>it's ability to produce current (amps) in excess of the load on the
>>system.
>
>True.
>
>Brian Lloyd 361 Catterline Way
Brian,
We both agree that voltage drop is caused by the alternator's
inability to produce enough current (amps) to meet system
demands. What I was trying to express, is that it would be more
likely for the pilot (Dale) to notice a drop in voltage first. This
is why Bob N recommends a low voltage warning system. When alternator
output drops below what is being consumed by the ship's systems,
voltage will always sag.
Charlie
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
At 05:08 PM 7/4/2006, you wrote:
>
>
>On Jul 4, 2006, at 3:16 PM, Charlie Kuss wrote:
>
>>At 02:02 PM 7/4/2006, you wrote:
>>>Output diodes comprise the rectifier. (converts AC current to DC)
>>>For the purposes of the alternators we use, the rectifier is
>>>comprised of 6 diodes. These diodes can fail in two modes, open or
>>>short. Failing open (diode blows apart) is the more common
>>>failure mode. In this mode, each diode that fails will reduce the
>>>alternator's output by 1/6th.
>>>Charlie,
>>
>>>Does the reduce output show as lower voltage and/or reduced
>>>maximum amps?
>>>Dale Ensing
>>
>>Dale,
>>snipped
>
>>If the load on the electrical system is below the crippled
>>alternator's ability to produce power, you may not notice any
>>difference.
>
>I agree with that but you will start to hear one heck of an
>alternator whine.
In most situations you are correct. Unfortunately, the absence of
whine doesn't mean that everything is rosy. Like they say, one test
is worth a thousand expert opinions. Another is: Test, don't guess.
snipped
Charlie
________________________________________________________________________________
| From: | "Harold" <kayce33(at)earthlink.net> |
| Subject: | For the gmc filter try Mail Frontier |
Hi all,
I have a filter for SPAM, Mail Frontier. It seems to work fairly well, gets
about 80% of the garbage mail. I'm confident that it will filter gmc....at
any rate we'll see
Harold
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
Bob & Listers,
I wish to install a remote Ident push button for my Garmin GTX320A
transponder. I want to use a momentary push button using a standard
1/2" bushing plan form. I'm trying to select an appropriate switch
for this purpose. I called Garmin's support to find out how much
current goes through this circuit. The tech couldn't tell me, as he
did not have that info at his disposal. He did say that the
instructions said that the circuit should have no more than 0.5 amps.
When pressed further, he looked at the circuit and told me that the
switch grounded one leg of a transistor in the transponder.
I am trying to figure out if:
#1 I should specify a switch with gold (low current draw)
contacts or silver contacts? According to NKK's catalog, their
switches with gold contacts are for 0.4 amps or less.
#2 Will it matter if the contacts are fast or slow "make and break"?
#3 Required amp rating of the switch.
Charlie Kuss
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Switch question |
Charlie Kuss wrote:
>
>
> Bob & Listers,
> I wish to install a remote Ident push button for my Garmin GTX320A
> transponder. I want to use a momentary push button using a standard
> 1/2" bushing plan form. I'm trying to select an appropriate switch for
> this purpose. I called Garmin's support to find out how much current
> goes through this circuit. The tech couldn't tell me, as he did not
> have that info at his disposal. He did say that the instructions said
> that the circuit should have no more than 0.5 amps.
> When pressed further, he looked at the circuit and told me that the
> switch grounded one leg of a transistor in the transponder.
> I am trying to figure out if:
> #1 I should specify a switch with gold (low current draw) contacts
> or silver contacts? According to NKK's catalog, their switches with
> gold contacts are for 0.4 amps or less.
>
> #2 Will it matter if the contacts are fast or slow "make and break"?
>
> #3 Required amp rating of the switch.
>
> Charlie Kuss
Hi Charlie,
I can't offer an answer with 'authority', but experience with modern
electronics would indicate that current demands should be minimal for
any switch other than the power switch (and even the power switch is
usually wimpy these days; only used to activate a solid state relay in a
lot of stuff). Call the tech back & ask him which lead of the transistor
is switched to ground. It's almost certainly the 'base' if it's a normal
silicon transistor or the 'gate' if it's an FET. If either is the case,
there will be very low current demand, likely way under 1/10 amp.
If I were doing the install in my plane, I'd just try to find something
that looked & mounted like I wanted & had good reliability with minimal
'excercise' to keep contacts clean because I wouldn't expect to be
needing the ident button very often.
I bet if you open up the xponder & look at the internal ident button, it
will be something you can buy from Mouser or Digikey for less than a dollar.
Charlie
(electronics tech in a previous life)
Slobovia Outernational
flying RV-4, -7 fuselage
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 4, 2006, at 6:55 PM, Charlie Kuss wrote:
>
> Brian,
> We both agree that voltage drop is caused by the alternator's
> inability to produce enough current (amps) to meet system demands.
> What I was trying to express, is that it would be more likely for
> the pilot (Dale) to notice a drop in voltage first. This is why Bob
> N recommends a low voltage warning system. When alternator output
> drops below what is being consumed by the ship's systems, voltage
> will always sag.
Very true. But until you reach the point where the alternator can't
carry the load, system voltage will appear normal.
You know, Bob used to sell a loadmeter/voltmeter that had the ability
to measure field voltage (voltage across the field windings which is
proportional to field current). What would be apparent is a sudden
increase in field voltage for the same RPM and load. Another
advantage of externally regulated alternators.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 4, 2006, at 6:47 PM, Charlie Kuss wrote:
>
> I've tested alternators which would meet the output spec (for a
> limited time) Then one (or more) of the rectifier diodes would
> overheat and short. My point here is that not all failures are
> "hard" failures. When diagnosing a charging system you can't always
> rely on what "theory" says should happen. :-(
Ah, you are telling me that the difference between theory and
practice in practice is greater than the difference between theory
and practice in theory? OK, I agree with that. ;-)
>> I understand your logic Charlie but, as I indicated above, I don't
>> think it will work the way you have outlined.
>>
>> But this was just an off-the-top-of-my-head analysis and very will
>> could be wrong.
>>
>> Brian Lloyd 361 Catterline Way
>
> My experience here is anecdotal, as it simply relates to what I've
> seen in my experiences.
Ah, real-life trumps theory. Yeah, I can go with that too.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Switch question |
On Jul 4, 2006, at 8:31 PM, Charlie Kuss wrote:
> I am trying to figure out if:
> #1 I should specify a switch with gold (low current draw)
> contacts or silver contacts? According to NKK's catalog, their
> switches with gold contacts are for 0.4 amps or less.
Go for the gold.
>
> #2 Will it matter if the contacts are fast or slow "make and
> break"?
It shouldn't. Since the ident circuit is basically a latching timer,
it can bounce the the cows come home and that will have no effect on
the behavior of the xpdr.
>
> #3 Required amp rating of the switch.
I would guess about 10ma -- yes, milliamps.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator failure thoughts |
In a message dated 7/4/2006 9:25:44 PM Eastern Standard Time,
chaztuna(at)adelphia.net writes:
For the purposes of the alternators we use, the rectifier is
comprised of 6 diodes. These diodes can fail in two modes, open or
short. Failing open (diode blows apart) is the more common
failure mode. In this mode, each diode that fails will reduce the
alternator's output by 1/6th.
Charlie,
Charlie:
Why 6 diodes? Half wave rectification only requires 2 diodes. And Full
wave reverification only requires 4 diodes. So why 6 and how are they hooked
up?
Barry
"Chop'd Liver"
________________________________________________________________________________
| Subject: | Re: Alternator failure thoughts |
> Why 6 diodes? Half wave rectification only requires 2 diodes. And
> Full wave reverification only requires 4 diodes. So why 6 and how are
> they hooked up?
>
> Barry
> "Chop'd Liver"
Hi Barry,
Those alternators are 3 phase.
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: Alternator failure. Info provided |
Bob, if you want a beta tester when you get the system developed, let me
know. I could be a good candidate. I have new IR 60amp alternator that is
waiting to be installed if the ER alt. from Vans fails which is controlled
by a B&C LR3; but I could make the switch sooner. Larry in Indiana with
flying RV7
>
>
>
> Don't worry about it. There's a system under development
> that's easy to add on to any existing system that provides
> the any-time/any-conditions absolute control over a
> stock automotive alternator. The risks for not having it
> right now are low. If you want OV protection now, you can
> install the original Z-24 configuration knowing that the
> ultimate solution will use the b-lead contactor and alternator
> control switch. The straight transorb approach hypothesized
> on the last figure of page 4 will not work. We've got
> a plan-E . . . or is it "F" . . . anyhow, the solution
> will not be difficult or expensive.
>
> See:
> http://www.aeroelectric.com/articles/Alternator_Failures.pdf
>
>
> Bob . . .
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 5, 2006, at 6:57 AM, FLYaDIVE(at)aol.com wrote:
> In a message dated 7/4/2006 9:25:44 PM Eastern Standard Time,
> chaztuna(at)adelphia.net writes:
> For the purposes of the alternators we use, the rectifier is
> comprised of 6 diodes. These diodes can fail in two modes, open or
> short. Failing open (diode blows apart) is the more common
> failure mode. In this mode, each diode that fails will reduce the
> alternator's output by 1/6th.
> Charlie,
> Charlie:
>
> Why 6 diodes? Half wave rectification only requires 2 diodes.
For a single winding, half-wave rectification only needs one diode.
> And Full wave reverification only requires 4 diodes. So why 6 and
> how are they hooked up?
It would be possible to write a whole dissertation on this subject.
The alternator is three phase. There are three windings in the stator
of the alternator. Each one by itself produces a full AC wave but
each one has its phase starting 120 degrees after the phase of the
previous winding. Imagine a sine wave starting at zero, rising to a
positive peak at 90 degrees, crossing zero again at 180 degrees,
rising (falling?) to a negative peak at 270 degrees, and then coming
back to zero at 360 degrees to start the whole cycle over again. Now
imagine that the next winding starts its wave at zero just as the
waveform from the first winding is on its downward slope between 90
and 180 degrees. Do this again for the third winding. (This stuff is
hard to describe in words without pictures.)
If you think of how a full-wave bridge rectifier is connected to a
single winding (as in a transformer) You see that each leg of the
transformer has two diodes connected to it -- one going from ground
to the winding and another going from the winding to output. So each
leg of the transformer requires two diodes, one to conduct the
positive half of the cycle to the positive output and the other to
connect the negative half of the cycle to ground.
Since we have a three-phase device we have three windings, not just
one. It turns out that you can save diodes by hooking the three
windings together so you end up with only three leads total. They are
hooked up in either delta configuration or wye ('Y') configuration.
Here, let me try to draw a picture. The letter 'W' will denote a
winding and 'T' will denote a connection terminal:
Delta:
T
/ \
W W
/ \
T---W---T
Wye:
T
|
W
|
t
/ \
W W
/ \
T T
(The center-tap terminal in the wye configuration is often not used
so I made it a small 't'.)
Most alternators are wired in wye configuration. Each of the three
main terminals gets two diodes, one each for the positive and
negative half-cycle of the waveform available at that terminal.
BTW, if your alternator has a 'stator' terminal (the Delco
alternators do) it is usually the center-tap terminal. On boats the
AC at this terminal is used to drive the tachometer. The frequency is
proportional to engine speed. Having your tach drop to zero while the
engine is running is a good indication you have lost your alternator.
(This is how I usually find out I have burned up another stator.)
BTW, if you are wondering about how you can 'short' all the windings
together in the delta configuration without hurting anything you will
find that the voltage at the free ends of any two windings connected
together (vector sum) will be equal and opposite in phase to the
voltage on the other winding so no current will flow.
>
> Barry
> "Chop'd Liver"
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | PWilson <pwmac(at)sisna.com> |
| Subject: | Re: Alternator failure thoughts |
Its interesting about the number of diodes used
in alternators. The Ford alternator used in
recent vehicles has 8 diodes and a regulator
bolted to the back of the case. I have not been
able to determine if the field wire is externally
accessible. Anyhow, the 95130/160/200amp versions
of the 3G alternator are physically pretty big
for a plane. A schematic and other details can be
found at:
http://fullsizebronco.com/forum/showthread.php?t=55169&highlight=alternator
I would appreciate an explanation of for all the diodes.
The guy who sells the upgraded alternators also
sells various pulleys if anybody has interest.
His link is buried in the above site.
Regards, Paul
=========================
At 06:35 AM 7/5/2006, you wrote:
>
>
>On Jul 5, 2006, at 6:57 AM, FLYaDIVE(at)aol.com wrote:
>
>>In a message dated 7/4/2006 9:25:44 PM Eastern Standard Time,
>>chaztuna(at)adelphia.net writes:
>>For the purposes of the alternators we use, the rectifier is
>>comprised of 6 diodes. These diodes can fail in two modes, open or
>>short. Failing open (diode blows apart) is the more common
>>failure mode. In this mode, each diode that fails will reduce the
>>alternator's output by 1/6th.
>>Charlie,
>>Charlie:
>>
>>Why 6 diodes? Half wave rectification only requires 2 diodes.
>
>For a single winding, half-wave rectification only needs one diode.
>
>>And Full wave reverification only requires 4 diodes. So why 6 and
>>how are they hooked up?
>
>It would be possible to write a whole dissertation on this subject.
>
>The alternator is three phase. There are three windings in the stator
>of the alternator. Each one by itself produces a full AC wave but
>each one has its phase starting 120 degrees after the phase of the
>previous winding. Imagine a sine wave starting at zero, rising to a
>positive peak at 90 degrees, crossing zero again at 180 degrees,
>rising (falling?) to a negative peak at 270 degrees, and then coming
>back to zero at 360 degrees to start the whole cycle over again. Now
>imagine that the next winding starts its wave at zero just as the
>waveform from the first winding is on its downward slope between 90
>and 180 degrees. Do this again for the third winding. (This stuff is
>hard to describe in words without pictures.)
>
>If you think of how a full-wave bridge rectifier is connected to a
>single winding (as in a transformer) You see that each leg of the
>transformer has two diodes connected to it -- one going from ground
>to the winding and another going from the winding to output. So each
>leg of the transformer requires two diodes, one to conduct the
>positive half of the cycle to the positive output and the other to
>connect the negative half of the cycle to ground.
>
>Since we have a three-phase device we have three windings, not just
>one. It turns out that you can save diodes by hooking the three
>windings together so you end up with only three leads total. They are
>hooked up in either delta configuration or wye ('Y') configuration.
>Here, let me try to draw a picture. The letter 'W' will denote a
>winding and 'T' will denote a connection terminal:
>
>Delta:
>
> T
> / \
> W W
> / \
> T---W---T
>
>Wye:
>
> T
> |
> W
> |
> t
> / \
> W W
> / \
> T T
>
>(The center-tap terminal in the wye configuration is often not used
>so I made it a small 't'.)
>
>Most alternators are wired in wye configuration. Each of the three
>main terminals gets two diodes, one each for the positive and
>negative half-cycle of the waveform available at that terminal.
>
>BTW, if your alternator has a 'stator' terminal (the Delco
>alternators do) it is usually the center-tap terminal. On boats the
>AC at this terminal is used to drive the tachometer. The frequency is
>proportional to engine speed. Having your tach drop to zero while the
>engine is running is a good indication you have lost your alternator.
>(This is how I usually find out I have burned up another stator.)
>
>BTW, if you are wondering about how you can 'short' all the windings
>together in the delta configuration without hurting anything you will
>find that the voltage at the free ends of any two windings connected
>together (vector sum) will be equal and opposite in phase to the
>voltage on the other winding so no current will flow.
>
>
>>
>>Barry
>>"Chop'd Liver"
>
>Brian Lloyd 361 Catterline Way
>brian-yak AT lloyd DOT com Folsom, CA 95630
>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
>I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| From: | "Jim Baker" <jlbaker(at)msbit.net> |
| Subject: | Re: Alternator failure thoughts |
> Its interesting about the number of diodes used
> in alternators. The Ford alternator used in
> recent vehicles has 8
Recall seeing an article that said Mercedes or BMW (forget
which) uses 12......
Jim Baker
580.788.2779
Elmore City, OK
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Alternator failure thoughts |
I'm not flying yet, but my 60 A ND ER alternator (of undetermined auto
application) has been modified by removing the stamped steel vented rear
cover and replacing it with a fiberglass closed cover with a stub to
accept a blast tube to force air over the diode plate, as an attempt to
compensate for a backward turning alt fan. Aside from buying a B&C or
Plane Power unit, is there a better way? Is this likely to have a
positive effect?
John
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
| Subject: | Alternator failure thoughts |
Not sure i understand this "backwards turning" deal. Frome what i can
see the internal fan alternators appear to have simply radial fan
blades that simply throw air out thru the sides of the alt. Therby
presumably sucking air in from both front and back.
Adding a cool air supply to the regulator should therefore augment the
existing fan. I am thinking of doing a similar thing by riveting
something similar to the stamped rear cover of my Autozone Toyota Camry
special.
Cetainly couldn't hurt
Frank
________________________________
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John
Burnaby
Sent: Wednesday, July 05, 2006 8:55 AM
I'm not flying yet, but my 60 A ND ER alternator (of undetermined auto
application) has been modified by removing the stamped steel vented rear
cover and replacing it with a fiberglass closed cover with a stub to
accept a blast tube to force air over the diode plate, as an attempt to
compensate for a backward turning alt fan. Aside from buying a B&C or
Plane Power unit, is there a better way? Is this likely to have a
positive effect?
John
________________________________________________________________________________
| From: | "Don Honabach" <don.honabach(at)pcperfect.com> |
| Subject: | Battery Contactor - HOT... |
I'm in the process of wiring up my panel and noticed that the battery
contactor gets fairly hot (don't have an exact temperature, but so hot
that you wouldn't leave your finger on it for more than a second, but
probably not hot enough to burn you in any 'real' way).
Since I'm only running between 1 to 2A rights now during testing (just a
few instruments connected), I'm assuming the heat is being generated by
the contactor's internal 'switch mechanism'. It also appears to be
hottest at the bottom of the contactor.
Is this normal?
In case you're curious, the unit is a continuous duty contactor and
meant for this type of application.
As always, thanks in advance for your help!
Don
________________________________________________________________________________
| Subject: | Re: Battery Contactor - HOT... |
Don Honabach a crit :
>
> Im in the process of wiring up my panel and noticed that the battery
> contactor gets fairly hot (dont have an exact temperature, but so hot
> that you wouldnt leave your finger on it for more than a second, but
> probably not hot enough to burn you in any real way).
>
>
Hi Don,
This seems quite normal to me.
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| From: | PWilson <pwmac(at)sisna.com> |
| Subject: | Re: Alternator failure thoughts Paul - Barry |
RE: Ford 8 diode alternator
I don't belong to that forum and it pops up without a password
Here is another link that has the same info It works for me and I
don't belong to that forum either.
http://www.foureyedpride.com/phpBB2/viewtopic.php?t=23682
Regards, Paul
====================================
At 10:09 AM 7/5/2006, you wrote:
>Paul:
>
>I could not access the site you gave the link for. Seems it requires a
>password.
>
>http://fullsizebronco.com/forum/showthread.php?t=55169&highlight=alternator
>
>Any other way I can get in, or you could copy the page and send it to me?
>
>Barry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 5, 2006, at 10:23 AM, PWilson wrote:
> I would appreciate an explanation of for all the diodes.
Well, as I said in my earlier post, there are two diodes for each leg
in the stator. You may find some alternators that have diodes in
parallel to carry more current. That would lead to there being 12
diodes in some cases. (Diodes do not parallel well as one diode of a
parallel pair will hog more of the current.)
Nippon Denso adds two more diodes going to the center tap of the wye
which will help the alternator keep going if one of the stator
windings happens to fail open.
If there are more diodes over and above the (basically) six output
diodes then they are there to provide power to the internal
regulator. The most typical system I have seen has three extra diodes
to provide the power to the regulator. Nippon Denso just gets its
regulator power from the B-lead. This means that whenever the battery
is connected to the alternator the alternator is using some amount of
battery power but the full power to the field is not switched on (it
would kill the battery in a couple of hours) until power is applied
to the 'I' lead. This is generally not a problem for an aircraft
application as the battery is disconnected from the alternator when
the battery master contactor is switched off.
In most other alternators there is no way for current to flow from
the battery to the regulator. You either have to provide start-up
power for the regulator through the ignition ('I') or idiot-lamp
('L') terminals, or you have to spin the alternator fast enough that
the residual magnetism in the armature will generate enough to get
the internal regulator to start sending some on to the field.
Does that help?
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Battery Contactor - HOT... |
On Jul 5, 2006, at 1:14 PM, Don Honabach wrote:
> Im in the process of wiring up my panel and noticed that the
> battery contactor gets fairly hot (dont have an exact temperature,
> but so hot that you wouldnt leave your finger on it for more than
> a second, but probably not hot enough to burn you in any real
> way). ...
> Is this normal?
Yes. There is about 1A flowing through the coil to hold the contactor
closed. Since it is not doing any other work that 1A at 12V is turned
into 12 watts of heat. That is enough to make the contactor get quite
warm. But that is how it is designed to work.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Battery Contactor - HOT... |
In a message dated 7/5/06 1:22:49 PM Eastern Daylight Time,
don.honabach(at)pcperfect.com writes:
> Since I'm only running between 1 to 2A rights now during testing (just a
> few instruments connected), I'm assuming the heat is being generated by
> the contactor's internal 'switch mechanism'. It also appears to be
> hottest at the bottom of the contactor.
========================================
Don:
I can understand WARM but not HOT! I honestly have never checked the
temperature of the Master or Starter relays but so hot that you can't touch it
and
keep your fingers on it does NOT seem correct.
My first thought is ... Did you Mix Up the relays? The Master Relay is rated
as CONTINUOUS DUTY while the Starter Relay is rated only INTERMITTENT DUTY.
If you mixed them up then SURE! The one used as Master would get HOT ...
Probably Very HOT!
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Jerry2DT(at)aol.com |
| Subject: | Re: Alternator failure thoughts |
Charlie, IIRC you are an automotive technician so I am curious... In your
years in that industry, how many alternators did you see fail mechanically
enough to toss parts and pieces around? Before I retired 8 years ago, I owned a
shop with 4 busy mechanics, many alternator failures we saw, but I don't
recall one that destroyed itself that way. We saw a few that seized and destroyed
the belt, but that's about it.
Jerry Cochran
>snipped
>I have seen a number of alternator failures on cars, boats, and
>airplanes. Some were pretty simple, no-brainer failures and some were
>"HOLY S--T" failures. I thought I would toss in here the ways I can
>see alternators failing (and have failed) and then address the failures.
>
>Here are the failure modes I have see so far (feel free to add to
>this list):
>
>1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output (destroys battery and
> anything
>else attached to the bus)
snipped
Brian,
I'd like to expand on item C of the list above
Output diodes comprise the rectifier. (converts AC current to
DC) For the purposes of the alternators we use, the rectifier is
comprised of 6 diodes. These diodes can fail in two modes, open or
short. Failing open (diode blows apart) is the more common failure
mode. In this mode, each diode that fails will reduce the
alternator's output by 1/6th.
Diodes that fail shorted are more insidious. Often, the pilot will
not notice a decrease in performance. However, he/she will generally
notice an increase in noise (generally on the radios) This is because
1/6th of the alternator's output is now bleeding through as AC
current. The ship's electrical system is designed for DC current. The
one item which really can not tolerate AC current is the battery. Any
time an alternator fails, it is best to do a postmortem, to determine
the cause.
Shorted rectifier diodes which are not repaired promptly, will soon
destroy the battery's storage capacity. This damage to the battery
may not be noticed, without conducting a battery output test. This is
important if you subscribe to Bob N's ideas regarding battery only
emergency operations.
Charlie Kuss
________________________________________________________________________________
| From: | PWilson <pwmac(at)sisna.com> |
| Subject: | Re: Alternator failure thoughts |
Thanks Brian it helps
===============
At 11:57 AM 7/5/2006, you wrote:
>
>On Jul 5, 2006, at 10:23 AM, PWilson wrote:
>
>>I would appreciate an explanation of for all the diodes.
>
>Well, as I said in my earlier post, there are two diodes for each leg
>in the stator. You may find some alternators that have diodes in
>parallel to carry more current. That would lead to there being 12
>diodes in some cases. (Diodes do not parallel well as one diode of a
>parallel pair will hog more of the current.)
>
>Nippon Denso adds two more diodes going to the center tap of the wye
>which will help the alternator keep going if one of the stator
>windings happens to fail open.
>
>If there are more diodes over and above the (basically) six output
>diodes then they are there to provide power to the internal
>regulator. The most typical system I have seen has three extra diodes
>to provide the power to the regulator. Nippon Denso just gets its
>regulator power from the B-lead. This means that whenever the battery
>is connected to the alternator the alternator is using some amount of
>battery power but the full power to the field is not switched on (it
>would kill the battery in a couple of hours) until power is applied
>to the 'I' lead. This is generally not a problem for an aircraft
>application as the battery is disconnected from the alternator when
>the battery master contactor is switched off.
>
>In most other alternators there is no way for current to flow from
>the battery to the regulator. You either have to provide start-up
>power for the regulator through the ignition ('I') or idiot-lamp
>('L') terminals, or you have to spin the alternator fast enough that
>the residual magnetism in the armature will generate enough to get
>the internal regulator to start sending some on to the field.
>
>Does that help?
>
>Brian Lloyd 361 Catterline Way
>brian-yak AT lloyd DOT com Folsom, CA 95630
>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
>I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| Subject: | Re: Alternator failure thoughts |
I have run a auto salvage business for 20 years and I cannot
recall ever seeing or hearing of an exploded alternator. I have seen
many of them seized up as you mention. It is hard to say how many I've
sold (several thousand I would guess) And I have never heard of any
damage to an auto engine resulting from an alternator seize. I would
guess most auto engines will cruise somewhere between 2000 and 3000 rpms
which would put it close to what an airplane engine is run. But on a
long drive I would guess the alternator would see 4000 and above rpm's
in an automobile many times while downshifting to pass, going uphill,
accelerating from stop etc, which in an airplane the max will normally
be around 2700 rpm. Accually the alt itself would see a much higher rpm
possibly twice or more that of the engine rpm's since the crank pulley
is generally at least twice the circumference of the alt pulley on an
auto engine and probably around 3 times difference on the airplane crank
vs. alt pulley. Which would make the alt rpm's much higher than an auto
if the same sized alt pulley. Taking into consideration the higher rpm's
of the auto engine the alt maximum seen rpm's difference between the
aircraft and auto alt's would be somewhere close I would think,
especially if the airplane alt pulley was larger. I am not saying that
an alt seizing cannot explode or damage an engine but I would think it
very rare. My observations are deffinately not scientific but I should
think a good indicator of the rarity.
Randy
----- Original Message -----
From: Jerry2DT(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Wednesday, July 05, 2006 1:37 PM
Subject: AeroElectric-List: Re: Alternator failure thoughts
Charlie, IIRC you are an automotive technician so I am curious... In
your years in that industry, how many alternators did you see fail
mechanically enough to toss parts and pieces around? Before I retired 8
years ago, I owned a shop with 4 busy mechanics, many alternator
failures we saw, but I don't recall one that destroyed itself that way.
We saw a few that seized and destroyed the belt, but that's about it.
Jerry Cochran
From: Charlie Kuss <chaztuna(at)adelphia.net>
Subject: Re: AeroElectric-List: Alternator failure thoughts
>snipped
>I have seen a number of alternator failures on cars, boats, and
>airplanes. Some were pretty simple, no-brainer failures and some
were
>"HOLY S--T" failures. I thought I would toss in here the ways I can
>see alternators failing (and have failed) and then address the
failures.
>
>Here are the failure modes I have see so far (feel free to add to
>this list):
>
>1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output (destroys battery
and
> anything
>else attached to the bus)
snipped
Brian,
I'd like to expand on item C of the list above
Output diodes comprise the rectifier. (converts AC current to
DC) For the purposes of the alternators we use, the rectifier is
comprised of 6 diodes. These diodes can fail in two modes, open or
short. Failing open (diode blows apart) is the more common failure
mode. In this mode, each diode that fails will reduce the
alternator's output by 1/6th.
Diodes that fail shorted are more insidious. Often, the pilot will
not notice a decrease in performance. However, he/she will generally
notice an increase in noise (generally on the radios) This is
because
1/6th of the alternator's output is now bleeding through as AC
current. The ship's electrical system is designed for DC current.
The
one item which really can not tolerate AC current is the battery.
Any
time an alternator fails, it is best to do a postmortem, to
determine
the cause.
Shorted rectifier diodes which are not repaired promptly, will
soon
destroy the battery's storage capacity. This damage to the battery
may not be noticed, without conducting a battery output test. This
is
important if you subscribe to Bob N's ideas regarding battery only
emergency operations.
Charlie Kuss
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
| Subject: | Re: Alternator failure thoughts |
The standard large pully on lyc is around 9.5 inches so the alt speed
does get up there even at a cruise of around 2400 RPM.
Mind you if the alt seized I'm sure it would simply vapourise the belt.
Can't imaging the belt will absorb more than 30HP without breaking.
Hard to see it stopping an engine....At leats I hope not...:)
Frank
________________________________
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Brinker
Sent: Wednesday, July 05, 2006 1:06 PM
I have run a auto salvage business for 20 years and I cannot
recall ever seeing or hearing of an exploded alternator. I have seen
many of them seized up as you mention. It is hard to say how many I've
sold (several thousand I would guess) And I have never heard of any
damage to an auto engine resulting from an alternator seize. I would
guess most auto engines will cruise somewhere between 2000 and 3000 rpms
which would put it close to what an airplane engine is run. But on a
long drive I would guess the alternator would see 4000 and above rpm's
in an automobile many times while downshifting to pass, going uphill,
accelerating from stop etc, which in an airplane the max will normally
be around 2700 rpm. Accually the alt itself would see a much higher rpm
possibly twice or more that of the engine rpm's since the crank pulley
is generally at least twice the circumference of the alt pulley on an
auto engine and probably around 3 times difference on the airplane crank
vs. alt pulley. Which would make the alt rpm's much higher than an auto
if the same sized alt pulley. Taking into consideration the higher rpm's
of the auto engine the alt maximum seen rpm's difference between the
aircraft and auto alt's would be somewhere close I would think,
especially if the airplane alt pulley was larger. I am not saying that
an alt seizing cannot explode or damage an engine but I would think it
very rare. My observations are deffinately not scientific but I should
think a good indicator of the rarity.
Randy
----- Original Message -----
From: Jerry2DT(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Wednesday, July 05, 2006 1:37 PM
Subject: AeroElectric-List: Re: Alternator failure thoughts
Charlie, IIRC you are an automotive technician so I am
curious... In your years in that industry, how many alternators did you
see fail mechanically enough to toss parts and pieces around? Before I
retired 8 years ago, I owned a shop with 4 busy mechanics, many
alternator failures we saw, but I don't recall one that destroyed itself
that way. We saw a few that seized and destroyed the belt, but that's
about it.
Jerry Cochran
From: Charlie Kuss <chaztuna(at)adelphia.net>
Subject: Re: AeroElectric-List: Alternator failure
thoughts
>snipped
>I have seen a number of alternator failures on cars,
boats, and
>airplanes. Some were pretty simple, no-brainer failures
and some were
>"HOLY S--T" failures. I thought I would toss in here
the ways I can
>see alternators failing (and have failed) and then
address the failures.
>
>Here are the failure modes I have see so far (feel free
to add to
>this list):
>
>1. Straight electrical failures:
>
> a. regulator failed -- no output
> b. brushes failed -- no output
> c. output diode failure -- whine and reduced
output
> d. diode trio failure -- no output
> e. regulator failed -- runaway output
(destroys battery and
> anything
>else attached to the bus)
snipped
Brian,
I'd like to expand on item C of the list above
Output diodes comprise the rectifier. (converts AC
current to
DC) For the purposes of the alternators we use, the
rectifier is
comprised of 6 diodes. These diodes can fail in two
modes, open or
short. Failing open (diode blows apart) is the more
common failure
mode. In this mode, each diode that fails will reduce
the
alternator's output by 1/6th.
Diodes that fail shorted are more insidious. Often,
the pilot will
not notice a decrease in performance. However, he/she
will generally
notice an increase in noise (generally on the radios)
This is because
1/6th of the alternator's output is now bleeding through
as AC
current. The ship's electrical system is designed for DC
current. The
one item which really can not tolerate AC current is the
battery. Any
time an alternator fails, it is best to do a postmortem,
to determine
the cause.
Shorted rectifier diodes which are not repaired
promptly, will soon
destroy the battery's storage capacity. This damage to
the battery
may not be noticed, without conducting a battery output
test. This is
important if you subscribe to Bob N's ideas regarding
battery only
emergency operations.
Charlie Kuss
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
---- Jerry2DT(at)aol.com wrote:
>
> Charlie, IIRC you are an automotive technician so I am curious... In your
> years in that industry, how many alternators did you see fail mechanically
> enough to toss parts and pieces around? Before I retired 8 years ago, I owned
a
> shop with 4 busy mechanics, many alternator failures we saw, but I don't
> recall one that destroyed itself that way. We saw a few that seized and destroyed
> the belt, but that's about it.
>
> Jerry Cochran
snipped
Jerry,
I, like you, own an auto repair shop. I have never in 30+ years seen an automobile
alternator "explode". It just doesn't happen. What did happen, back in the
days when cars mounted alternators like is done on light aircraft, was that
the adjuster bracket cracked and broke. The alternator then starts bouncing
around. If the driver didn't shut the engine down fairly soon, it would attempt
to depart the engine. On most light aircraft, the normal operating noises would
preclude any chance of you hearing this situation in time to do anything about
it.
You have two brackets, the pivot bracket and the adjuster bracket. The adjuster
bracket is the long arm with the slotted hole in it. These brackets broke with
some regularity back before the use of large cast mounting and tensioning pulleys.
They would break for one of two reasons.
#1 The brackets were under designed for the load. I think that the bracket supplied
by Vans Aircraft is marginal here. (I'm building an RV-8A, so that's my
reference point with experimental aircarft)
#2 Due to carelessness or poor workmanship during an alternator replacement, a
mechanic omitted some of the retaining hardware for the alternator or it's brackets.
Most common was loosing the large "fender" (think AN970) washer between the adjuster
bolt and the slotted hole in the adjuster bracket. This would concentrate
the vibratory stresses around the hex head of the bolt at the adjuster bracket.
The adjuster bracket is weak due to the adjustment slot machined (or broached)
into it. The purpose of the fender washer was to spread the stress over
an area large enough to absorb it, and to reinforce this less than steller mount
design.
I also have a background in aerospace machine assembly. I was taught that any
metal surface less than 1/4" thick should have a flat washer installed between
the bolts (or nut) and the surface it bore down on (in this case the bracket)
Another rule of thumb is that all brackets should be triangulated. By this I mean
that they should have 3 mounting points. Two points should attach to the engine
and one to the alternator.
Many aviation (and decades old cars) did not meet either of these engineering
rules of thumb. Most RV alternator adjusting brackets have this failing. The adjustment
bracket mounts to the engine with only one fastener and to the alternator
with one fastener. Compound the problem with the following agrivating conditions.
#1 The 4 cylinder Lycoming's reputation to mimic a wet dog during start up and
shut down.
#2 An adjustment slot that is much longer than necessary to do the job.
So you have 3 conditions which are trying to destroy your adjustment bracket. I
suggest to the listers that they ensure that their alternator mounting system
is stout enough to do the job. Also take care when installing and removing the
mounting hardware to it.
Charlie Kuss
________________________________________________________________________________
| Subject: | Re: Alternator failure thoughts |
Thanks for that info. I have a loose IO-540 flywheel that
measures 9 3/4" I measured it to the outside, Lyc. may get their
measurement from down in the groove. That spurred me to check some
automobile measurements (I have aprox. 150 or so engines on my engine
rack from anything from a chevy v-8 to a 4cyl foreign) It was
interesting to see the varying sizes on the crankshaft pulley's, they
ranged from aprox. 4 1/2" to 8". Of course many of them had double and
triple pulley system, so not sure which one would have been the alt.
pulley. Although the largest 8" was a single crank pulley system off of
a 99 Plymouth Breeze ( I am 99% sure it was a single pulley system, I
found no indications of any other pulleys that may have been bolted to
it).
I also went thru my alternator racks and got various
different pulley measurements. They ranged from aprox. 2 1/4" to 2 7/8"
although I am almost certain I have seen some over 3" in diameter in the
past but just not on the rack at this time.
Keep in mind these measurements we're all outside pulley
measurements. I did not even try to figure the diameter where the belt
accually rides. I would guess the shoulder measurements we're anywhere
from 1/8" to 1/4" on the serpintine types and probably around 1/2" deep
for the v-belt type.
So from my perspective, there are some auto's that approach the
Lyc. flywheel size so the alt. rpm's difference would not be extremely
far apart and some of the auto alt's would probably surpass the airplane
alt. rpm speed ( although most do not ) while in an acceleration. But
even if only say 10% of the auto alt's would exceed the airplanes rpm's
even only 10% of the time that would be I believe a significant enough
number to say that if it we're a real world problem with them exploding
we would have seen at least one.
Nope not exactly scientific data but I hope this may give some
perspective. Of course I thru in some Randy rambling logic for free.
Sorry for the rant.
Rambling Randy
----- Original Message -----
From: Hinde, Frank George (Corvallis)
To: aeroelectric-list(at)matronics.com
Sent: Wednesday, July 05, 2006 3:36 PM
Subject: RE: AeroElectric-List: Re: Alternator failure thoughts
The standard large pully on lyc is around 9.5 inches so the alt speed
does get up there even at a cruise of around 2400 RPM.
Mind you if the alt seized I'm sure it would simply vapourise the
belt. Can't imaging the belt will absorb more than 30HP without
breaking. Hard to see it stopping an engine....At leats I hope not...:)
Frank
-------------------------------------------------------------------------
-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Brinker
Sent: Wednesday, July 05, 2006 1:06 PM
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: Alternator failure thoughts
I have run a auto salvage business for 20 years and I cannot
recall ever seeing or hearing of an exploded alternator. I have seen
many of them seized up as you mention. It is hard to say how many I've
sold (several thousand I would guess) And I have never heard of any
damage to an auto engine resulting from an alternator seize. I would
guess most auto engines will cruise somewhere between 2000 and 3000 rpms
which would put it close to what an airplane engine is run. But on a
long drive I would guess the alternator would see 4000 and above rpm's
in an automobile many times while downshifting to pass, going uphill,
accelerating from stop etc, which in an airplane the max will normally
be around 2700 rpm. Accually the alt itself would see a much higher rpm
possibly twice or more that of the engine rpm's since the crank pulley
is generally at least twice the circumference of the alt pulley on an
auto engine and probably around 3 times difference on the airplane crank
vs. alt pulley. Which would make the alt rpm's much higher than an auto
if the same sized alt pulley. Taking into consideration the higher rpm's
of the auto engine the alt maximum seen rpm's difference between the
aircraft and auto alt's would be somewhere close I would think,
especially if the airplane alt pulley was larger. I am not saying that
an alt seizing cannot explode or damage an engine but I would think it
very rare. My observations are deffinately not scientific but I should
think a good indicator of the rarity.
Randy
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 5, 2006, at 4:36 PM, Hinde, Frank George (Corvallis) wrote:
> The standard large pully on lyc is around 9.5 inches so the alt
> speed does get up there even at a cruise of around 2400 RPM.
> Mind you if the alt seized I'm sure it would simply vapourise the
> belt. Can't imaging the belt will absorb more than 30HP without
> breaking. Hard to see it stopping an engine....At leats I hope
> not...:)
I think it more likely that the mounting ears could break and the
alternator could find itself bouncing around in the cowling. I don't
think it will turn into a grenade but who knows.
Brian Lloyd 361 Catterline Way
brianl at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
"Five percent of the people think.
Ten percent of the people think they think.
Eighty-five percent of the people would rather die than think."
---Thomas A. Edison
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | alternator failure modes |
I have had several people write to me to tell me that they have never
seen an alternator turn into a grenade. Neither have I. I was just
listing that is a *possible* scenario, as in, "I suppose this might
happen." I think it unlikely but I do think that things like broken
brackets, having the alternator seize, and who knows what happens if
both happen at once.
The key point is that there are mechanical failure modes, not just
electrical failure modes. When the alternator stops producing power
it is not just an electrical problem. If one were to fly for a longer
period of time something bad could happen that would make the
situation much worse.
I still hold that it is a good idea to land and check things out even
if you have a backup alternator or lots of battery capacity.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Robert G. Wright" <armywrights(at)adelphia.net> |
| Subject: | Bob's Ground Power Plug button |
I've been slowly working on Bob Nuckolls' design for the ground power plug
made out of the Cole-Hersey Piper-style plug/socket. I couldn't get the
insulating button out with pliers or other methods so I figured I'd try to
be careful as I heated up the rear screw for solder. Of course, it got too
hot and melted. I emailed Cole-Hersey (CH) on the website and got a message
to call local dealers. Dealers, come to find out, don't carry little parts,
just the end item.
I finally talked to someone at CH who had to go down to the assembly
line/warehouse to find the little buttons, then sent me four for free when I
only requested one that I would pay for, and who was also kind enough to
write the part number on the little baggie when she sent them to me.
Awesome job at customer service. If anyone else has had this problem,
before you go buy a new plug or find a decades-old salvage part, call CH up
and ask for part number 11055-25.
Rob Wright
RV-10 #392
________________________________________________________________________________
| Subject: | Re: alternator failure modes |
Yep it's not like we can coast to the side of the road when we have a
major problem. Better safe than sorry. And hey we might even make a friend
at our non scheduled destination. If there's one thing I've noticed in my
relatively short flying experiences is that airport folks are generally
friendly and willing to help.
Randy
----- Original Message -----
Sent: Wednesday, July 05, 2006 6:07 PM
>
> I have had several people write to me to tell me that they have never
> seen an alternator turn into a grenade. Neither have I. I was just
> listing that is a *possible* scenario, as in, "I suppose this might
> happen." I think it unlikely but I do think that things like broken
> brackets, having the alternator seize, and who knows what happens if both
> happen at once.
>
> The key point is that there are mechanical failure modes, not just
> electrical failure modes. When the alternator stops producing power it is
> not just an electrical problem. If one were to fly for a longer period of
> time something bad could happen that would make the situation much worse.
>
> I still hold that it is a good idea to land and check things out even if
> you have a backup alternator or lots of battery capacity.
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator failure. Info provided |
>
>
>Bob, if you want a beta tester when you get the system developed, let me
>know. I could be a good candidate. I have new IR 60amp alternator that
>is waiting to be installed if the ER alt. from Vans fails which is
>controlled by a B&C LR3; but I could make the switch sooner. Larry in
>Indiana with flying RV7
I'll keep it in mind. There will be some beta-systems shipped
to builders who are willing and able to provide best-practical
turn-around for proofing installation instructions and product
performance.
Thanks for the offer!
Bob . . .
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
| Subject: | Strange power source |
I got this today from a relative who lives in Florida:
.our son-in-law, had an underground electrical service line burn up about
two months ago. The electric company came with a two wheel hand truck
mounted metal box (heavy, had a hoist on it to get it back in the truck) to
replace his electric service. They cut the service line into his meter,
removed it, plugged in, and then plugged back in the meter. It ran his
house for over a month, including air conditioner, water heater, stove, etc.
I crawled all over the device, and there was not a line coming to it. It
worked just like a battery, and was silent. I could not find a manufactures
nameplate, a property number, any thing but a number stamped into the box
with the word "Deland" (name of the town that the service company is located
in).
What a hell of a backup generator, and with the wheels on it, we could just
lift the hood, roll it into the front of our vehicle, and replace the "gas
burner". I'm not making much progress in locating the manufacturer of this
device (has to be a fuel cell). Progress Energy, headquartered in the
Carolinas, is the electric company. If you see anything, let me know, this
thing was awesome.
I thought one of you might know more about what he is talking about. Sounds
interesting!
Terry
RV-8A
Seattle
________________________________________________________________________________
| From: | "Bret Smith" <smithhb(at)tds.net> |
| Subject: | Annunciator Project |
Bob,
Speaking of test projects, have you heard anything from your "design crew"
about the annunciator project? Prospective buyers want to know.
Bret Smith
RV-9A (91314)
Mineral Bluff, GA
www.FlightInnovations.com
________________________________________________________________________________
| From: | PeterHunt1(at)aol.com |
| Subject: | Load Meter Question |
Bob:
When I first installed the load meter you sold me it read 25%. Now, with
the same instruments/electrical equipment on it reads 16%. The decrease from
25% to 16% has taken place gradually over the past 20 hours of flight time and
it just seems to me that this decrease is substantial. No lights,
instruments or other electrical equipment have failed. Any thoughts on what may
be
causing this decrease in load meter reading?
Pete in Clearwater
RV-6, Reserve Grand Champion - Kit, Sun 'n Fun 2006
All electric panel
Heading for Oshkosh
________________________________________________________________________________
| From: | "Jim Butcher" <europa(at)triton.net> |
I'm having difficulty trouble shooting a charging system problem. The
install is a Rotax 914 in an Europa XS. Besides the Rotax alternator, I
have a B&C L60 alternator driven off the crankshaft and a B&C LR3C
regulator. The electrical system is basically AeroElectric Z-13. I have
recently completed the 50 hour inspection of the airframe and engine.
There were no problems found with the charging system and the battery
(Panasonic LC-X1220P 20 aH) is only 18 mos old with 50 hours of use. It
passed a capacity test with the same result as when new.
The aircraft is equipped with 3 ammeters - one on the battery positive
and one on each alternator output. What I observed during flight and
subsequent testing today is that the battery ammeter shows -3 amps (a 3
amp discharge) all the time, regardless of load - ie turning on pitot
heat doesn't change the value - it's still a 3 amp discharge. Data from
flights prior to the maintenance showed 0 amps at this spot as expected.
The problem is present with either alternator on line and both of them
operate correctly, proven by loading heavily (pitot heat) and noting the
amp output.
Any suggestions on where to look? Might there be a problem with this
battery where it can't accept a charge properly? The bus voltage runs
14.1 - 14.2 volts which is what B&C recommends.
Thanks
Jim Butcher
Europa XS N241BW
________________________________________________________________________________
| From: | "Jerry & Ledy Esquenazi" <jlinga(at)mchsi.com> |
| Subject: | RE: Insrument Lighting |
Hey Guys,
Thanks to Eric, Ken , and Charlie for your suggestions. However, I
don't have any idea on how to build a PWM or variable duty cycle
circuit. Do you guys have any schematics or more info? Thanks Charlie
for including the link.
I don't plan on disconnecting the instrument or covering it up. I
have the g-meter lit for aesthetics and symmetry. I paid extra to have
it lit, so I plan on using it.
I called the manufacturer of the g-meter. The reason the instrument
is so bright is that it actually has three bulbs drawing a total of
0.56. The company verified my amp draw correct for a 12 v unit. So at
least I know I have the right bulbs. I still need to dim it down a bit
to make the brightness similar to the rest of the instruments. Bob K.,
do you have any ideas?
Thank you,
Jerry
Hi Jerry
I'd say you did it all correctly but you are just surprised at how much
the 2.5 watts heats up a resistor. A 5 watt bulb is about what
incandescent children's night lights are and does seem ridiculous for an
instrument so I agree that is is the wrong bulb. I would leave it as is
with your resistor. Second choice would be change the bulb to one that
is really 12 volts. Third choice is a variable duty cycle circuit that
pulses short 12 volt pulses to the lamp so that it averages the same
power as running it on 5 volts. That avoids heating up a resistor and
dumping the 2.5 watts but I doubt it is worth the trouble. Fourth choice
is kind of silly but if you had another similar instrument you could
wire them is series...
Ken
Jerry & Ledy Esquenazi wrote:
> Hey Guys,
> I have a simple problem that most likely has a simple solution.
> The solution, however, eludes me. I have an internally lit g-meter on
> my instrument panel (Don't ask me why :-)). The g-meter's lighting is
> internal to the instrument, i.e. it's not a lighting tray that is
> screwed to the top. The instrument would have to be opened up to get
> to the lamp.
>
> I purchased the g-meter from Chief a while back ago, and when I
> received it, I realized it was a 5v unit. Chief didn't have any other
> lighting option listed or available. I thought about dropping the
> voltage with a resistor. Before doing this I called the manufacturer
> Wultrad (aka Falcon Gauge). They said they had a 12v unit in stock
> that they could swap for mine. I thought... "great problem solved."
> They shipped me one back with a 12v label over the original label. In
> testing my instrument panel lighting, I discovered that the g-meter is
> considerably brighter than the other instruments to the point it would
> be annoying at night. The interesting thing is the light is nice and
> white and very uniform though out the face of the instrument. Anyway,
> I thought... "gee I'm back to putting in a resistor to dim the light!"
>
> "OK, no problem. I'll figure out what size resistor I need and
> move on," I thought. The problem is the resistance of any
> incandescent lamp changes whether it hot or cold. The lamp is drawing
> 0.56 A at 12.0 v. Seem's like a lot to me. From that I deduced the
> lamp's resistance at 21.3 ohm. The problem is that when I figure out
> what size resistor I need to get say a 7 or 8 v voltage drop across
> the lamp and add that resistor to the circuit, the current changes and
> so does the resistance of the lamp. So how does one figure this stuff
> out? I decided to purchase a potentiometer and install it in my
> circuit, adjust it 'till I got the brightness I wanted and then
> measure the resistance of the pot. In doing this I began to smell
> smoke, the little pot was beginning to glow red as I dimmed down the
> light in the instrument. I went back and purchased a heavier pot.
> This did the trick. I decided a 20 ohm resistor in series would be
> perfect. I purchased a 22 ohm, 2 W resistor, temporarily installed
> it, and the light was perfect. The problem was I was still smelling
> that familiar acrid smell. I had a 7.4 v drop across the resistor and
> a .34 A current giving me 2.5 W to dissipate. I later tried two 10
> ohm, 2 W resistors in series. Still, they got too hot. I purchased a
> ceramic 22 ohm, 5 W resistor and it still got too hot to touch. The
> small battery I was using for testing was putting out 12.2 v under the
> load. I had a 7.4 v drop across the resistor, So I deduced I must be
> getting a 4.8 v drop across the lamp. The light was just right. I
> wonder if I still have a 5v lamp inside the instrument! I measured
> 0.34 A in the circuit. The 5 W resistor ought to be handling the 2.5
> W I need to dissipate just fine. Something is wrong. Do any of you
> smart guys know what I'm doing wrong?
>
> Jerry
> "Smelling smoke in Georgia
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
A recent post regarding alternator abuse mentioned using an
automotive belt on the alternator rather than an aircraft belt.
That's the first I ever heard regarding an "aircraft alternator
belt." I always thought a V- belt is a V-belt.
The belt furnished with my B&C 60 Amp alternator was too short. I
replaced it with a belt from an auto parts store. Seems to work okay.
Am I asking for trouble?
Charlie Brame
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | "Ed Anderson" <eanderson(at)carolina.rr.com> |
| Subject: | Re: Alternator Belt |
Charlie, I've found that good quality auto V belts like made by GATES give
no problem. However, I have had some poor experience with lesser quality
brands. I only use GATES belts myself.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
----- Original Message -----
Sent: Thursday, July 06, 2006 4:59 AM
>
> A recent post regarding alternator abuse mentioned using an automotive
> belt on the alternator rather than an aircraft belt. That's the first I
> ever heard regarding an "aircraft alternator belt." I always thought a V-
> belt is a V-belt.
>
> The belt furnished with my B&C 60 Amp alternator was too short. I
> replaced it with a belt from an auto parts store. Seems to work okay.
>
> Am I asking for trouble?
>
> Charlie Brame
> RV-6A N11CB
> San Antonio
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: Alternator Belt |
No problem. Just be sure you got a good one. Vans aircraft recommends using
a Yates belt. I would not use a no name special, Stick with a strong
brand name and premium grade. Larry in Indiana
----- Original Message -----
Sent: Thursday, July 06, 2006 3:59 AM
>
> A recent post regarding alternator abuse mentioned using an automotive
> belt on the alternator rather than an aircraft belt. That's the first I
> ever heard regarding an "aircraft alternator belt." I always thought a V-
> belt is a V-belt.
>
> The belt furnished with my B&C 60 Amp alternator was too short. I
> replaced it with a belt from an auto parts store. Seems to work okay.
>
> Am I asking for trouble?
>
> Charlie Brame
> RV-6A N11CB
> San Antonio
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: RE: Insrument Lighting |
Jerry:
I hate the place, but take a ride to Radio Shack. Get an LM-317 voltage
regulator, right on the packaging there is a schematic of how to build and what
parts are required for a very effective voltage regulator.
The hardest and most frustrating part is dealing with the total mental
midgets behind the counter. They don't know the difference between a diode,
resistor or a capacitor. And god forbid, they get off their ass and look for
something or say anything more than, "If you don't see it we don't have it." Or,
"Want to buy a cell phone?"
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Load Meter Question |
In a message dated 7/5/06 10:37:49 PM Eastern Daylight Time,
PeterHunt1(at)aol.com writes:
> Any thoughts on what may be
> causing this decrease in load meter reading?
>
> Pete in Clearwater
> RV-6, Reserve Grand Champion - Kit, Sun 'n Fun 2006
> All electric panel
> Heading for Oshkosh
==================================
Pete:
Let's make the assumption that the meter is reading correctly. Then there is
only two conditions considering all your above checks are correct.
The two conditions are really one just at different ends of the circuit.
Vibration has improved the connection(s). Either on the B+ side or on the Ground
side.
Since metal planes tend to use the plane as the common ground I have seen
quite a few problems solved by improving the systems grounds.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: alternator failure modes |
In a message dated 7/5/06 7:53:06 PM Eastern Daylight Time,
brinker@cox-internet.com writes:
> If there's one thing I've noticed in my
> relatively short flying experiences is that airport folks are generally
> friendly and willing to help.
>
> Randy
================
Yup, as long as you keep away from the FBO's.
And look for the EAA types.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator Belt |
>
>A recent post regarding alternator abuse mentioned using an
>automotive belt on the alternator rather than an aircraft belt.
>That's the first I ever heard regarding an "aircraft alternator
>belt." I always thought a V- belt is a V-belt.
>
>The belt furnished with my B&C 60 Amp alternator was too short. I
>replaced it with a belt from an auto parts store. Seems to work okay.
There's no such thing as an "aircraft alternator belt". There
are thousands of belts by hundreds of manufacturers and they
range in SERVICE LIFE from mediocre to the best-we-know how
to do.
There may be folks who are on a par with GATES for the
manufacture of belts but I'm not personally familiar with
who they might be. Perhaps folks on the list who work in
that venue can offer some insight as to alternative brands.
>Am I asking for trouble?
Not if you've crafted your architecture and pilot's mind-set
for failure tolerant operation. Broken belts are but one of
many reasons an alternator might decided to quit. If you're
prepared to deal with an alternator failure on your own terms,
then no, you're not asking for trouble. But you may decided to
'upgrade' a belt because you're tired of replacing it. See
chapter 17 in the 'Connection.
I've seen airplanes at fly-ins where the owner has installed
a 'spare' belt over the prop shaft and secured it. This would
allow a failed belt to be replaced in the field without
pulling the prop. Given the extra-ordinary stress that a
belt gets when driving a small-pulley alternator such as
the B&C, it's probably money well spent to get the best.
Give B&C a call and ask about their experience with Gates
belts (that's the brand that probably came with your alternator).
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Instrument Lighting was RE: Insrument |
Jerry,
I scanned the first page of the assembly sheet for the MPJA pulse
width controller. See
http://www.mpja.com/productview.asp?product=4057+MD
I've sent it to you off list. I can scan the 2nd page if this is not
enough. I've built 3 of these units. I had very little experience
with electronics kits previous to assembling these. The first unit
took 1.5 hours to build. (reading and understanding the
instructions) The third unit only took 0.5 hour to assemble. For a
dimmer circuit, the slide switch shown on the diagram can be omitted.
It's purpose is only to allow polarity reversal for reversing
direction of a motor.
Charlie Kuss
>Hey Guys,
> Thanks to Eric, Ken , and Charlie for your
> suggestions. However, I don't have any idea on how to build a PWM
> or variable duty cycle circuit. Do you guys have any schematics or
> more info? Thanks Charlie for including the link.
> I don't plan on disconnecting the instrument or covering it
> up. I have the g-meter lit for aesthetics and symmetry. I paid
> extra to have it lit, so I plan on using it.
> I called the manufacturer of the g-meter. The reason the
> instrument is so bright is that it actually has three bulbs drawing
> a total of 0.56. The company verified my amp draw correct for a 12
> v unit. So at least I know I have the right bulbs. I still need
> to dim it down a bit to make the brightness similar to the rest of
> the instruments. Bob K., do you have any ideas?
>
>Thank you,
>Jerry
>
><klehman(at)albedo.net>
>
>Hi Jerry
>I'd say you did it all correctly but you are just surprised at how much
>the 2.5 watts heats up a resistor. A 5 watt bulb is about what
>incandescent children's night lights are and does seem ridiculous for an
>instrument so I agree that is is the wrong bulb. I would leave it as is
>with your resistor. Second choice would be change the bulb to one that
>is really 12 volts. Third choice is a variable duty cycle circuit that
>pulses short 12 volt pulses to the lamp so that it averages the same
>power as running it on 5 volts. That avoids heating up a resistor and
>dumping the 2.5 watts but I doubt it is worth the trouble. Fourth choice
>is kind of silly but if you had another similar instrument you could
>wire them is series...
>Ken
>
>Jerry & Ledy Esquenazi wrote:
>
> > Hey Guys,
> > I have a simple problem that most likely has a simple solution.
> > The solution, however, eludes me. I have an internally lit g-meter on
> > my instrument panel (Don't ask me why :-)). The g-meter's lighting is
> > internal to the instrument, i.e. it's not a lighting tray that is
> > screwed to the top. The instrument would have to be opened up to get
> > to the lamp.
> >
> > I purchased the g-meter from Chief a while back ago, and when I
> > received it, I realized it was a 5v unit. Chief didn't have any other
> > lighting option listed or available. I thought about dropping the
> > voltage with a resistor. Before doing this I called the manufacturer
> > Wultrad (aka Falcon Gauge). They said they had a 12v unit in stock
> > that they could swap for mine. I thought... "great problem solved."
> > They shipped me one back with a 12v label over the original label. In
> > testing my instrument panel lighting, I discovered that the g-meter is
> > considerably brighter than the other instruments to the point it would
> > be annoying at night. The interesting thing is the light is nice and
> > white and very uniform though out the face of the instrument. Anyway,
> > I thought... "gee I'm back to putting in a resistor to dim the light!"
> >
> > "OK, no problem. I'll figure out what size resistor I need and
> > move on," I thought. The problem is the resistance of any
> > incandescent lamp changes whether it hot or cold. The lamp is drawing
> > 0.56 A at 12.0 v. Seem's like a lot to me. From that I deduced the
> > lamp's resistance at 21.3 ohm. The problem is that when I figure out
> > what size resistor I need to get say a 7 or 8 v voltage drop across
> > the lamp and add that resistor to the circuit, the current changes and
> > so does the resistance of the lamp. So how does one figure this stuff
> > out? I decided to purchase a potentiometer and install it in my
> > circuit, adjust it 'till I got the brightness I wanted and then
> > measure the resistance of the pot. In doing this I began to smell
> > smoke, the little pot was beginning to glow red as I dimmed down the
> > light in the instrument. I went back and purchased a heavier pot.
> > This did the trick. I decided a 20 ohm resistor in series would be
> > perfect. I purchased a 22 ohm, 2 W resistor, temporarily installed
> > it, and the light was perfect. The problem was I was still smelling
> > that familiar acrid smell. I had a 7.4 v drop across the resistor and
> > a .34 A current giving me 2.5 W to dissipate. I later tried two 10
> > ohm, 2 W resistors in series. Still, they got too hot. I purchased a
> > ceramic 22 ohm, 5 W resistor and it still got too hot to touch. The
> > small battery I was using for testing was putting out 12.2 v under the
> > load. I had a 7.4 v drop across the resistor, So I deduced I must be
> > getting a 4.8 v drop across the lamp. The light was just right. I
> > wonder if I still have a 5v lamp inside the instrument! I measured
> > 0.34 A in the circuit. The 5 W resistor ought to be handling the 2.5
> > W I need to dissipate just fine. Something is wrong. Do any of you
> > smart guys know what I'm doing wrong?
> >
> > Jerry
> > "Smelling smoke in Georgia
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Alternator failure thoughts |
Frank
All cars except Honda products, spin their alternators in the
opposite direction than Lycomings. Air is supposed to be sucked into
the alternator (longitudinally) at both the front and rear (fans at
both ends) and expelled through the grates in the center of the case
(radially). Correct fan rotation aids in cooling, as incoming air
from the cowl is going into the front of the alternator. Also,
cooling shrouds on the rear of the alternator are more effective. All
that said, Bob N says that using an ND off of a Toyota or other
vehicle won't greatly affect the cooling of the unit. The air will
simply be drawn in from the center and expelled out the ends.
Charlie Kuss
>Not sure i understand this "backwards turning" deal. Frome what i
>can see the internal fan alternators appear to have simply radial
>fan blades that simply throw air out thru the sides of the alt.
>Therby presumably sucking air in from both front and back.
>
>Adding a cool air supply to the regulator should therefore augment
>the existing fan. I am thinking of doing a similar thing by riveting
>something similar to the stamped rear cover of my Autozone Toyota
>Camry special.
>
>Cetainly couldn't hurt
>
>Frank
>
>
>----------
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John Burnaby
>Sent: Wednesday, July 05, 2006 8:55 AM
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: Alternator failure thoughts
>
>I'm not flying yet, but my 60 A ND ER alternator (of undetermined
>auto application) has been modified by removing the stamped steel
>vented rear cover and replacing it with a fiberglass closed cover
>with a stub to accept a blast tube to force air over the diode
>plate, as an attempt to compensate for a backward turning alt fan.
>Aside from buying a B&C or Plane Power unit, is there a better way?
>Is this likely to have a positive effect?
>
>John
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator Belt |
>snipped
>
> There's no such thing as an "aircraft alternator belt". There
> are thousands of belts by hundreds of manufacturers and they
> range in SERVICE LIFE from mediocre to the best-we-know how
> to do.
>
> There may be folks who are on a par with GATES for the
> manufacture of belts but I'm not personally familiar with
> who they might be. Perhaps folks on the list who work in
> that venue can offer some insight as to alternative brands.
>snipped
> Bob . . .
Listers,
I will second the recommendation of Gates belts. On a par with
Gates is the OEM belt supplier for most Japanese cars. The
manufacturer is Bando. In the past year, I've found Bando belts
easily available from the after-market. I have only found one "off
brand" belt which compares to these two. The brand name is Force One.
It comes in a black and white cardboard sheath. My local parts
supplier carries this brand and I'm impressed with the quality. On
the other hand, I would not use a Dayco brand belt on a go kart!
Charlie Kuss
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator failure thoughts |
>I'm not flying yet, but my 60 A ND ER alternator (of undetermined auto
>application) has been modified by removing the stamped steel vented rear
>cover and replacing it with a fiberglass closed cover with a stub to
>accept a blast tube to force air over the diode plate, as an attempt to
>compensate for a backward turning alt fan. Aside from buying a B&C or
>Plane Power unit, is there a better way? Is this likely to have a positive
>effect?
>
>John
Positive, forced air cooling of an alternator is never a bad thing
to do. The question that has always plagued the OBAM aircraft
community continues to be: "Is cooling necessary?"
Until we mount an effort to gather meaningful temperature data
internal to the alternator under various electrical loads and
flight conditions (hot-day, Vx climb), etc.
From the viewpoint of regulators who have blessed an
electrical load analysis based on what the alternator's nameplate
ratings, now they want to see if installation
issues (drive ratios and cooling) will produce the power
your load analysis claims.
We know that very few OBAM aircraft will ever need all of
the alternator's nameplate power. We also know that cooling
effectiveness of air movement under the cowl can be strongly
influenced by changes in baffling, cowl geometry, accessory
locations, belt ratios, etc.
The bright side of all this uncertainty is that few alternators
fail in OBAM aircraft for reasons obviously attributable to
heat . . . nonetheless, when some poor builder is on his
third in a string of alternator failures, cooling is one
of several things to be explored. The standard approach is to
add some form of blast cooling and hope the next alternator
survives.
In the past half-dozen or so seminars, I've offered to help
any interested builder in crafting a test plan and then
providing them with the data acquisition system that would
let us investigate alternator cooling issues on their
airplane. The same activity would work toward development of
a testing model and an article that might encourage others
to add further test data to the library. So far, no takers.
It occurs to me that recent discussions on alternator
"failures" may have suffered from a lack of definition for
the word. As a professional in TC aviation I've come to understand
that failures come in three broad classes: (1) failure due to
lack of due-diligence in observance of manufacturer's instructions.
(2) failure to meet design goals for operating performance.
(3) failure to meet reasonable (or guaranteed) expectations for
service life. In the TC aircraft world, "failure" is applied
to those devices that required replacement or disassembly for
refurbishment/upgrading.
The perception of value for service life is a BIG driver
in the supplier/consumer relationship. I recall a conversation
with one of our hangar renters at 1K1 who was telling me that
TBO on his ultra-light engine was about 300 hours! 2000 hour, TC
engine drivers sitting on the porch with us were aghast.
I remember thinking that was about 6 years of average flying.
He quickly followed up that he was already on his "second engine"
having overhauled it on a Saturday afternoon for $600 worth of
parts. Hmmmm $2/hr for parts. 6 hours labor. Not a "bad"
return on investment as long as the device wears in an orderly
manner such that the owner can choose when to do replacement
or refurbishment based on inspection.
When looking over the various postings on the 'net concerning
ANY product, one needs to sort out discussions for relevance
against your working definition of failure and a host of other
issues. These include user understanding for both the
basic physics of the system augmented with skill of the
writers of installation instructions. One can find a great
deal of discussion about a lot of products where root cause
of the discussion is NOT a failure of the product but
a customer service issue. This is where the manufacturer
has an opportunity to excel. One can have the best-we-know-
how-to-do product and still gather less-than-stellar reviews
if the customer doesn't get whatever support is necessary
for satisfactory installation and operation.
I can cite you a great example of how a once admired
supplier to RAC has crapped in their mess kit by failing
to go the extra mile with customer support. A product I
designed for them 25 years ago has been replaced under
warranty in the field at a cost of $millions$. It didn't take
much investigation to find that installation and trouble-shooting
instructions were poor. The supplier's attitude is that
"The parts go out of here meeting all quality assurance
requirements. We've done everything we signed up to do."
Nonetheless, hundreds of no-fault-found units get replaced for
lack of understanding. As far as purchasing is concerned,
the computer records don't lie. They see losses against that
part in $millions$, the project group thinks the supplier
is incompetent, the users just shrug it off as the high cost
of owning an airplane and the supplier says "we did what
we signed up to do." The thing that really irks me
personally is the fact that my name is on all the drawings
that define how the thing is built and few persons who
pick those drawings up see the big picture and understand
why there is so much grief. The easy and common thing to
do is curse those "ivory tower" engineers . . . My momma
told me that I would be judged by the company I keep.
Took me 40 years to understand what she was talking about.
The supplier is now on the @!#@-list and not likely
to get new business from that project group. The recipes
for success call for much more than the elegant design.
You need to be prepared to support your product from
cradle to grave whether problems are your fault or not.
Failure to do so can severely damage a perfectly good
reputation for really stupid reasons that start with
ignorance of the supporting simple-ideas.
Bob . . .
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Load Meter Question |
On Jul 5, 2006, at 10:32 PM, PeterHunt1(at)aol.com wrote:
> Bob:
>
> When I first installed the load meter you sold me it read 25%.
> Now, with the same instruments/electrical equipment on it reads
> 16%. The decrease from 25% to 16% has taken place gradually over
> the past 20 hours of flight time and it just seems to me that this
> decrease is substantial. No lights, instruments or other
> electrical equipment have failed. Any thoughts on what may be
> causing this decrease in load meter reading?
Your battery may have been low in charge. Over the past 25 hours it
has finally reached full charge. That is all I can think of.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Charging System |
On Jul 5, 2006, at 10:40 PM, Jim Butcher wrote:
> The aircraft is equipped with 3 ammeters - one on the battery
> positive and one on each alternator output. What I observed during
> flight and subsequent testing today is that the battery ammeter
> shows -3 amps (a 3 amp discharge) all the time, regardless of load
> - ie turning on pitot heat doesnt change the value - its still a
> 3 amp discharge. Data from flights prior to the maintenance showed
> 0 amps at this spot as expected. The problem is present with either
> alternator on line and both of them operate correctly, proven by
> loading heavily (pitot heat) and noting the amp output.
>
> Any suggestions on where to look? Might there be a problem with
> this battery where it cant accept a charge properly? The bus
> voltage runs 14.1 - 14.2 volts which is what B&C recommends.
If the bus voltage is 14.1 then the battery is charging. There is no
question about that. I would suspect the metering circuit.
Do you really have three ammeters or three shunts switched to one
ammeter? It sounds to me like you might have inadvertently switched
two of the leads to your shunt switch. (Presuming one ammeter).
Another possibility is that if you have hall-effect sensors the zero
setting on the one for the battery has become misadjusted.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | alternator temperature sensor |
Here is how Balmar senses temp on an alternator:
http://www.balmar.net/PDF/Temperaturesensormanuall.pdf
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 6, 2006, at 9:40 AM, Robert L. Nuckolls, III wrote:
>
>
>
>> I'm not flying yet, but my 60 A ND ER alternator (of undetermined
>> auto application) has been modified by removing the stamped steel
>> vented rear cover and replacing it with a fiberglass closed cover
>> with a stub to accept a blast tube to force air over the diode
>> plate, as an attempt to compensate for a backward turning alt fan.
>> Aside from buying a B&C or Plane Power unit, is there a better
>> way? Is this likely to have a positive effect?
>>
>> John
>
> Positive, forced air cooling of an alternator is never a bad thing
> to do. The question that has always plagued the OBAM aircraft
> community continues to be: "Is cooling necessary?"
>
> Until we mount an effort to gather meaningful temperature data
> internal to the alternator under various electrical loads and
> flight conditions (hot-day, Vx climb), etc.
That might not be too hard to do. Interesting thing is that the
Balmar alternator controllers include a temp sensor for the
alternator. If the alternator gets too hot the controller reduces
alternator output. They just bolt a thermistor to the alternator case
much like we do with a CHT sensor. That shouldn't be hard to craft at
all.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
| Subject: | Alternator failure thoughts |
Like I said i have not pulled and alt apart to see what it has but
radial fans come in three forms...Simple spade blades, forward curved
centrifugal and backards curved centrifugal.
I would bet the fan is a rudimentary backwards curved design. Either way
the fan will still flow air in the correct direction but not as
efficiently...I.e its still a centrifugal fan that sucks air into the
middle and throw radially outwards.
I have never personally done this but my suspicion was just confirmed by
one of my techs here in the office.
Bottom line is then running backwards will equate to less cooling flow
but is this an issue...Without instrumentation its impossible to tell.
Frank
________________________________
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Charlie Kuss
Sent: Thursday, July 06, 2006 6:33 AM
Frank
All cars except Honda products, spin their alternators in the opposite
direction than Lycomings. Air is supposed to be sucked into the
alternator (longitudinally) at both the front and rear (fans at both
ends) and expelled through the grates in the center of the case
(radially). Correct fan rotation aids in cooling, as incoming air from
the cowl is going into the front of the alternator. Also, cooling
shrouds on the rear of the alternator are more effective. All that said,
Bob N says that using an ND off of a Toyota or other vehicle won't
greatly affect the cooling of the unit. The air will simply be drawn in
from the center and expelled out the ends.
Charlie Kuss
Not sure i understand this "backwards turning" deal. Frome what
i can see the internal fan alternators appear to have simply radial fan
blades that simply throw air out thru the sides of the alt. Therby
presumably sucking air in from both front and back.
Adding a cool air supply to the regulator should therefore
augment the existing fan. I am thinking of doing a similar thing by
riveting something similar to the stamped rear cover of my Autozone
Toyota Camry special.
Cetainly couldn't hurt
Frank
________________________________
From: owner-aeroelectric-list-server(at)matronics.com [
mailto:owner-aeroelectric-list-server(at)matronics.com
] On Behalf Of
John Burnaby
Sent: Wednesday, July 05, 2006 8:55 AM
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Alternator failure thoughts
I'm not flying yet, but my 60 A ND ER alternator (of
undetermined auto application) has been modified by removing the stamped
steel vented rear cover and replacing it with a fiberglass closed cover
with a stub to accept a blast tube to force air over the diode plate, as
an attempt to compensate for a backward turning alt fan. Aside from
buying a B&C or Plane Power unit, is there a better way? Is this likely
to have a positive effect?
John
________________________________________________________________________________
| From: | "brian bollaert" <bbollaert(at)comcast.net> |
Hello
It is with infinite sadness that I must inform you all that Brian was in a
plane crash with two other pilots on Saturday July 1. He was not in his RV
and he was not the pilot.
He really enjoyed all the input and comraderie he felt from you all . He is
going to be very sorely missed.
Please tell me how to unsubscribe from here.
Sincerely,
Rebecca Bollaert
rbollaert(at)comcast.com
----- Original Message -----
Sent: Thursday, July 06, 2006 7:11 AM
>
> Here is how Balmar senses temp on an alternator:
>
> http://www.balmar.net/PDF/Temperaturesensormanuall.pdf
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| From: | "Harold" <kayce33(at)earthlink.net> |
| Subject: | Re: RE: Insrument Lighting |
I live on the wrong coast, but I've been to FRYS south of Portland, seems as
if they have something for everyone.
Harold
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator Belt |
In a message dated 7/6/06 9:17:59 AM Eastern Daylight Time, nuckollsr(at)cox.net
writes:
> There's no such thing as an "aircraft alternator belt". There
> are thousands of belts by hundreds of manufacturers and they
> range in SERVICE LIFE from mediocre to the best-we-know how
> to do.
======================================
Don't tell that to the FAA!
Here are the part numbers:
ALT BELT: 37A19773-37 <--- FAA Approved and with an FAA - PMA stamp. This
is the Gates Automotive equivalent: (gates belt 3V375).
Now, as I have stated before, there are quality differences. I have noted
that when it comes to Original Timing Belts and Serpentine Belts. The FACTORY
ORIGINAL is of much better quality than OEM or Auto Store items. See my long
post with explanation ... It should be in the archives.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "James Clark" <jclarkmail(at)gmail.com> |
So sorry to hear that.
Click on the first link in the message below and then go and click on the
"Subscribe/Unsubscribe" link. It will be self explanatory from there.
James
On 7/6/06, brian bollaert wrote:
>
> bbollaert(at)comcast.net>
>
> Hello
>
> It is with infinite sadness that I must inform you all that Brian was in
a
> plane crash with two other pilots on Saturday July 1. He was not in his
> RV
> and he was not the pilot.
>
> He really enjoyed all the input and comraderie he felt from you all . He
> is
> going to be very sorely missed.
>
> Please tell me how to unsubscribe from here.
>
> Sincerely,
>
>
> Rebecca Bollaert
> rbollaert(at)comcast.com
>
>
> ----- Original Message -----
> Sent: Thursday, July 06, 2006 7:11 AM
>
>
> brian-yak(at)lloyd.com>
> >
> > Here is how Balmar senses temp on an alternator:
> >
> > http://www.balmar.net/PDF/Temperaturesensormanuall.pdf
> >
> > Brian Lloyd 361 Catterline Way
> > brian-yak AT lloyd DOT com Folsom, CA 95630
> > +1.916.367.2131 (voice) +1.270.912.0788 (fax)
> >
> > I fly because it releases my mind from the tyranny of petty things . .
.
> > =97 Antoine de Saint-Exup=E9ry
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
=========================
===========
=========================
===========
=========================
===========
=========================
===========
>
>
--
This is an alternate email. Please continue to email me at
james(at)nextupventures.com .
________________________________________________________________________________
| From: | "Brett Ferrell" <bferrell(at)123mail.net> |
| Subject: | Sport Aviation 7/2006 article - Avionics Master |
Bob,
I'd love to hear your opinion on the "The Avionics Master - to Protect and
Defend" article in the July Sport Aviation, page 119 by George Wilhlmsen. I
don't know if you recieve it or not, it appears to not be available online
http://www.eaa.org/benefits/sportaviation/0607_toc.html though I could
probably scan it for you.
Brett
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
For those of you in other parts of the country or world who would not be
aware of Rebecca Bollaert's loss, here is the story from the Seattle Times
last Sunday.
Terry
Three Western Washington men killed in small-plane crash
By The Associated Press
DAVENPORT, Wash. - Three Western Washington men were killed when the
experimental aircraft they were in crashed during an attempted landing at
Seven Bays Airport west of Spokane.
The Lincoln County sheriff's office identified the victims as Charles W.
McCanna, 74, and Brian G. Bollaert, 56, both of Federal Way, and Michael B.
Ekholm, 50, of Monroe, KOMO Television reported Sunday.
The single-engine, homemade aircraft was registered to McCanna. It went down
Saturday afternoon about 30 miles north of Davenport in Lincoln County, said
FAA spokesman Mike O'Connor. Staff from the agency's Spokane office were
investigating, he said.
Witnesses said the plane's propeller hit the side of a gully, flipping it as
the pilot tried to land the plane.
"An eyewitness said they saw the plane in a pretty deep banking turn" before
crashing, said Kelly Watkins, chief criminal investigator for the Lincoln
County sheriff's office.
Copyright C 2006 The Seattle Times Company
Hello
It is with infinite sadness that I must inform you all that Brian was in a
plane crash with two other pilots on Saturday July 1. He was not in his RV
and he was not the pilot.
He really enjoyed all the input and comraderie he felt from you all . He is
going to be very sorely missed.
Please tell me how to unsubscribe from here.
Sincerely,
Rebecca Bollaert
rbollaert(at)comcast.com
>
>
________________________________________________________________________________
| From: | "Jeffery J. Morgan" <jmorgan(at)compnetconcepts.com> |
Thanks for the info.
Anyone know more info, such as how the prop hit a gully, but the wings
didn't? Is the airport in a valley? Being from not there, just trying
to get a picture.
Thanks
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Terry
Watson
Sent: Thursday, July 06, 2006 11:52 AM
-->
For those of you in other parts of the country or world who would not be
aware of Rebecca Bollaert's loss, here is the story from the Seattle
Times last Sunday.
Terry
Three Western Washington men killed in small-plane crash
By The Associated Press
DAVENPORT, Wash. - Three Western Washington men were killed when the
experimental aircraft they were in crashed during an attempted landing
at Seven Bays Airport west of Spokane.
The Lincoln County sheriff's office identified the victims as Charles W.
McCanna, 74, and Brian G. Bollaert, 56, both of Federal Way, and Michael
B.
Ekholm, 50, of Monroe, KOMO Television reported Sunday.
The single-engine, homemade aircraft was registered to McCanna. It went
down Saturday afternoon about 30 miles north of Davenport in Lincoln
County, said FAA spokesman Mike O'Connor. Staff from the agency's
Spokane office were investigating, he said.
Witnesses said the plane's propeller hit the side of a gully, flipping
it as the pilot tried to land the plane.
"An eyewitness said they saw the plane in a pretty deep banking turn"
before crashing, said Kelly Watkins, chief criminal investigator for the
Lincoln County sheriff's office.
Copyright C 2006 The Seattle Times Company
Hello
It is with infinite sadness that I must inform you all that Brian was in
a plane crash with two other pilots on Saturday July 1. He was not in
his RV and he was not the pilot.
He really enjoyed all the input and comraderie he felt from you all .
He is going to be very sorely missed.
Please tell me how to unsubscribe from here.
Sincerely,
Rebecca Bollaert
rbollaert(at)comcast.com
>
>
________________________________________________________________________________
| From: | James H Nelson <rv9jim(at)juno.com> |
Charlie,
I sell V-Belts for a living and other assorted sundry for
industrial items like bearings. There is two styles of "V" belts. one
configuration is "industrial" and the other is "automotive". The
difference is in the angle that makes the v-belt. The automotive is a
narrow "V" and the industrial "V" is a wider angle "V".. Industrial
belts are designated by their size. The first letter or number usually
designates the top width. Such as A-35 belt. This is a 1/2" wide belt
that is 35" in circumference on the inside. A 4L370 is physically the
same just a light duty "A" series. (don't ask !!) Think of the "L"
meaning light duty. There is a series called "3V or 3VX that is almost
the exact match to the belts used on aircraft engines. I will bring
home a 3vx belt and check it out on my engine. That should put the
confusion and sources to rest.
Jim Nelson
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | alternator health |
Bob, I loved your original alternator health-O-meter. How about a new
one that measures:
1. alternator load;
2. alternator voltage;
3. field voltage;
4. alternator frame temperature;
all in a single, compact, 2.25" instrument.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: alternator health |
I'll second that motion ....
It'll make trouble shooting easier.
Jerry Grimmonpre'
Do no archive
Bob, I loved your original alternator health-O-meter. How about a new
one that measures:
1. alternator load;
2. alternator voltage;
3. field voltage;
4. alternator frame temperature;
all in a single, compact, 2.25" instrument.
Brian Lloyd
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Alternator failure thoughts |
Frank
Thank you for correcting my misguided notion that running these fans backwards
would reverse the direction of air flow.
Charlie Kuss
---- "Hinde wrote:
> Like I said i have not pulled and alt apart to see what it has but
> radial fans come in three forms...Simple spade blades, forward curved
> centrifugal and backards curved centrifugal.
>
> I would bet the fan is a rudimentary backwards curved design. Either way
> the fan will still flow air in the correct direction but not as
> efficiently...I.e its still a centrifugal fan that sucks air into the
> middle and throw radially outwards.
>
> I have never personally done this but my suspicion was just confirmed by
> one of my techs here in the office.
>
> Bottom line is then running backwards will equate to less cooling flow
> but is this an issue...Without instrumentation its impossible to tell.
>
> Frank
>
>
>
> ________________________________
>
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Charlie Kuss
> Sent: Thursday, July 06, 2006 6:33 AM
>
>
> Frank
> All cars except Honda products, spin their alternators in the opposite
> direction than Lycomings. Air is supposed to be sucked into the
> alternator (longitudinally) at both the front and rear (fans at both
> ends) and expelled through the grates in the center of the case
> (radially). Correct fan rotation aids in cooling, as incoming air from
> the cowl is going into the front of the alternator. Also, cooling
> shrouds on the rear of the alternator are more effective. All that said,
> Bob N says that using an ND off of a Toyota or other vehicle won't
> greatly affect the cooling of the unit. The air will simply be drawn in
> from the center and expelled out the ends.
> Charlie Kuss
>
>
>
>
> Not sure i understand this "backwards turning" deal. Frome what
> i can see the internal fan alternators appear to have simply radial fan
> blades that simply throw air out thru the sides of the alt. Therby
> presumably sucking air in from both front and back.
>
> Adding a cool air supply to the regulator should therefore
> augment the existing fan. I am thinking of doing a similar thing by
> riveting something similar to the stamped rear cover of my Autozone
> Toyota Camry special.
>
> Cetainly couldn't hurt
>
> Frank
>
>
> ________________________________
>
> From: owner-aeroelectric-list-server(at)matronics.com [
> mailto:owner-aeroelectric-list-server(at)matronics.com
> ] On Behalf Of
> John Burnaby
> Sent: Wednesday, July 05, 2006 8:55 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Alternator failure thoughts
>
> I'm not flying yet, but my 60 A ND ER alternator (of
> undetermined auto application) has been modified by removing the stamped
> steel vented rear cover and replacing it with a fiberglass closed cover
> with a stub to accept a blast tube to force air over the diode plate, as
> an attempt to compensate for a backward turning alt fan. Aside from
> buying a B&C or Plane Power unit, is there a better way? Is this likely
> to have a positive effect?
>
> John
>
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator Belt |
James,
I am aware of the industrial Gates belts. I've also seen Gates heavy duty belts
referred to as Green Stripe. Are the Green Stripe Gates brand belts the same
as the industrial quality units? I often see these used in heavy machinery or
in medium and heavy duty trucks. Your recommendation to use the industrial quality
belts is well founded.
However, for the pilot who is AOG due to a broken belt, he may not be able to
find an industrial supplier close by the airport or open (weekends ya' know).
That means he has to resort to an auto or farm supply store. He still has a chance
of getting a good quality belt, if he knows what to ask for.
Thanks for adding to this discussion.
Charlie Kuss
---- James H Nelson wrote:
>
> Charlie,
> I sell V-Belts for a living and other assorted sundry for
> industrial items like bearings. There is two styles of "V" belts. one
> configuration is "industrial" and the other is "automotive". The
> difference is in the angle that makes the v-belt. The automotive is a
> narrow "V" and the industrial "V" is a wider angle "V".. Industrial
> belts are designated by their size. The first letter or number usually
> designates the top width. Such as A-35 belt. This is a 1/2" wide belt
> that is 35" in circumference on the inside. A 4L370 is physically the
> same just a light duty "A" series. (don't ask !!) Think of the "L"
> meaning light duty. There is a series called "3V or 3VX that is almost
> the exact match to the belts used on aircraft engines. I will bring
> home a 3vx belt and check it out on my engine. That should put the
> confusion and sources to rest.
>
>
> Jim Nelson
>
>
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
| Subject: | alternator health |
Just suck the data into an engine monitor like a Dynon and set an alarm
on each parameter.
Frank
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jerry
Grimmonpre
Sent: Thursday, July 06, 2006 11:14 AM
-->
I'll second that motion ....
It'll make trouble shooting easier.
Jerry Grimmonpre'
Do no archive
-->
Bob, I loved your original alternator health-O-meter. How about a new
one that measures:
1. alternator load;
2. alternator voltage;
3. field voltage;
4. alternator frame temperature;
all in a single, compact, 2.25" instrument.
Brian Lloyd
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: alternator health |
On Jul 6, 2006, at 2:35 PM, Hinde, Frank George (Corvallis) wrote:
> (Corvallis)"
>
> Just suck the data into an engine monitor like a Dynon and set an
> alarm
> on each parameter.
The only problem with that is, at least in the case of field voltage
or field current, it varies all over the map. It is proportional to
load (goes up when load is increased) and inversely proportional to
RPM (goes down as RPM increases). This means you have to know what
both the load and the RPM are doing to make sense of the field
voltage reading. I suspect that people will poke at the button and
get a feel for what the field voltage should be in cruise with a
normal load. If it jumps up then they will know that something has
changed in their alternator. This is not something you can set a hard
limit on.
BTW, Bob, I want one in a 24V flavor too. Maybe we should just use a
4-digit DVM.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Instrument lighting |
On Jul 6, 2006, at 1:53 PM, rd2(at)evenlink.com wrote:
>
> Would PWM be suitable for LEDs also?
Yes.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Instrument lighting |
Yes that works very well but as a rule you still need the current
limiting resistor. LED's draw so little power that a simple linear
regulator may be a bit easier and cheaper and may not even require a
heatsink. While you can put LED's and incandescant lamps on the same
dimmer they are unlikely to dim evenly so two different dimmers might be
required if you are picky about uniformly dimming panel lights. There
are ways of controlling multiple dimming circuits from one knob but of
course then one circuit failure can kill all the lights if that is a
concern.
Note that Bob has a LM-117 or LM-317 based linear regulator circuit for
a lamp dimmer on his aeroelectric site. Linear regulators are
essentially a solid state variable resistor and they dissipate as much
heat as a resistor would. But for panel lighting that may not be much
heat. I setup four of them in a row for panel dimming and they merely
get a bit warm. The efficiency is not much of an issue in an application
that doesn't require much power. A neat characteristic of these linear
regulators is that they protect themselves rather well from overheating
or short circuits so they are fairly resistant to abuse and they don't
generate noise. A PWM circuit may generate some electrical noise as it
rapidly switches the current on and off. I have seen some high end ANR
headsets that are sensitive to noise from some PWM panel dimmers.
Ken
rd2(at)evenlink.com wrote:
>
>Would PWM be suitable for LEDs also?
>
>Rumen
>
>_____________________Original message __________________________
> (received from Eric Ekberg; Date: 09:32 AM 7/4/2006
>-0500)
>________________________________________________________________
>I think what you did is fine, resistors are designed to get hot. However,
>if you want to reduce voltage efficiently use a simple PWM (pulse width
>modulated) voltage regulator circuit - you can build them for a dollar or
>two, they just use one IC and 2 or 3 resistors, and sometimes a heatsink.
>Look in one of the electronic catalogs. You can do a google search and
>come up with the design examples.
>
>eric
>snip
>
________________________________________________________________________________
| From: | "William Slaughter" <willslau(at)alumni.rice.edu> |
The Green Stripe belt was/is a "premium" automotive version. I have no specs
on how premium it is, but back in the day it was the preferred belt for
racing Corvairs, where the belt had to go over two idler pulleys, making the
trip from the horizontal crankshaft pulley, then turning 90 degrees to drive
the cooling fan mounted on a vertical axis, then back down another 90 degree
turn to rejoin the crankshft pulley. As you can imagine, this setup on a
6000+ rpm motor was quite a workout for the belt. Generic belts wouldn't
last a day, but the Green Stripe belts gave good service.
William Slaughter
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
chaztuna(at)adelphia.net
Sent: Thursday, July 06, 2006 1:08 PM
James,
I am aware of the industrial Gates belts. I've also seen Gates heavy duty
belts referred to as Green Stripe. Are the Green Stripe Gates brand belts
the same as the industrial quality units? I often see these used in heavy
machinery or in medium and heavy duty trucks. Your recommendation to use the
industrial quality belts is well founded.
However, for the pilot who is AOG due to a broken belt, he may not be able
to find an industrial supplier close by the airport or open (weekends ya'
know). That means he has to resort to an auto or farm supply store. He still
has a chance of getting a good quality belt, if he knows what to ask for.
Thanks for adding to this discussion. Charlie Kuss
---- James H Nelson wrote:
> -->
>
> Charlie,
> I sell V-Belts for a living and other assorted sundry for
> industrial items like bearings. There is two styles of "V" belts. one
> configuration is "industrial" and the other is "automotive". The
> difference is in the angle that makes the v-belt. The automotive is a
> narrow "V" and the industrial "V" is a wider angle "V".. Industrial
> belts are designated by their size. The first letter or number
> usually designates the top width. Such as A-35 belt. This is a 1/2"
> wide belt that is 35" in circumference on the inside. A 4L370 is
physically the
> same just a light duty "A" series. (don't ask !!) Think of the "L"
> meaning light duty. There is a series called "3V or 3VX that is almost
> the exact match to the belts used on aircraft engines. I will bring
> home a 3vx belt and check it out on my engine. That should put the
> confusion and sources to rest.
>
>
> Jim Nelson
>
>
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
snipped
> >John
>
> Positive, forced air cooling of an alternator is never a bad thing
> to do. The question that has always plagued the OBAM aircraft
> community continues to be: "Is cooling necessary?"
>
> Until we mount an effort to gather meaningful temperature data
> internal to the alternator under various electrical loads and
> flight conditions (hot-day, Vx climb), etc.
snipped
>
> We know that very few OBAM aircraft will ever need all of
> the alternator's nameplate power. We also know that cooling
> effectiveness of air movement under the cowl can be strongly
> influenced by changes in baffling, cowl geometry, accessory
> locations, belt ratios, etc.
snipped
> In the past half-dozen or so seminars, I've offered to help
> any interested builder in crafting a test plan and then
> providing them with the data acquisition system that would
> let us investigate alternator cooling issues on their
> airplane. The same activity would work toward development of
> a testing model and an article that might encourage others
> to add further test data to the library. So far, no takers.
snipped
> Bob . . .
Bob,
Where would you suggest mounting a thermister on an alternator to monitor temperature?
Charlie Kuss
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Sport Aviation 7/2006 article - |
>
>
>Bob,
>
>I'd love to hear your opinion on the "The Avionics Master - to Protect and
>Defend" article in the July Sport Aviation, page 119 by George
>Wilhlmsen. I don't know if you recieve it or not, it appears to not be
>available online
>http://www.eaa.org/benefits/sportaviation/0607_toc.html though I could
>probably scan it for you.
I let my EAA membership lapse this year. I only go to OSH
every 5-10 years (more often to support a client). EAA
and Sport Aviation in particular have lost their roots.
I just don't find them inspiring any more. I recall
having done an article on avionics master switches
that was published in SA about 10 years ago but I don't
seem to have a copy on this computer. However, here's a longer
thread on the topic I captured from some forums back about
that same time:
See: http://aeroelectric.com/articles/avmaster.pdf
It's sad to see old flags being run up the pole and saluted
year after year.
The only argument with strength advanced by modern deacons
of the AVMaster Church is that, "not all products offered to
the OBAM aircraft community benefit from DO-160 style design."
My response is, "Why not?" It's easy to do, it's not a secret
process. The only reason folks get away with marketing
unnecessarily fragile equipment is because uneducated customers
will buy it . . . and then take pains to manually protect the
device from gremlins the manufacturer should have taken care of
by design.
NOT the way to advance the art and science of building airplanes.
Bob . . .
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
At 06:57 AM 7/5/2006, you wrote:
>In a message dated 7/4/2006 9:25:44 PM Eastern Standard Time,
>chaztuna(at)adelphia.net writes:
>For the purposes of the alternators we use, the rectifier is
>comprised of 6 diodes. These diodes can fail in two modes, open or
>short. Failing open (diode blows apart) is the more common
>failure mode. In this mode, each diode that fails will reduce the
>alternator's output by 1/6th.
>Charlie,
>
>Charlie:
>
>Why 6 diodes? Half wave rectification only requires 2 diodes. And
>Full wave reverification only requires 4 diodes. So why 6 and how
>are they hooked up?
>
>Barry
>"Chop'd Liver"
Barry,
The ND alternators actually DO have 8 diodes. 6 of these rectify
the AC current from the 3 windings of the stator into DC current. The
main function of the other two diodes is to prevent the battery from
discharging back into the alternator when the engine is not running.
You have to remember that a DC motor and a generator are very
similar. You apply current into a motor to create mechanical motion.
With a generator (or alternator in this case) you apply mechanical
motion and a magnetic field to create electrical current.
If either of these two isolation diodes were to fail short, the
battery would discharge into the alternator. The alternator would act
like a seized motor. The input current from the battery can not turn
over the engine, via the alternator's pulley and drive belt.
Have you ever had a vehicle which operated OK when driven daily.
Yet, if allowed to sit unused for a number of days, the vehicle would
have a dead battery? Shorted isolation diodes in the alternator are
one possible cause of this situation.
Charlie Kuss
________________________________________________________________________________
| From: | Fiveonepw(at)aol.com |
| Subject: | Re: Instrument lighting |
In a message dated 07/06/2006 1:33:31 PM Central Daylight Time,
rd2(at)evenlink.com writes:
Would PWM be suitable for LEDs also?
>>>
Absolutely- I've been using one of the Marlin P. Jones PWM motor speed
control kits (as recently mentioned by Charlie Kuss) on my panel lights for 3 years
with most satisfactory results. All LEDs (many!) thus fed appear to be happy
so far...
Mark
________________________________________________________________________________
| From: | "Marty Martin" <martygmartin(at)gmail.com> |
| Subject: | Re: Battery Contactor - HOT... |
I have wing tip (3 light, white, (red or greed) & strobe. I'm putting the
firewall together, no engine to *rehang* as this was a flying Q200 to begin
with.
I woundering if I can just connect the battery to the leads that go to the
battery and check the lights for working condition.
Maybe I need to wait and rehang the motor.
Please let me know.
Greg Martin, martygmartin(at)gmail.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator failure thoughts |
>
>snipped
>
> > >John
> >
> > Positive, forced air cooling of an alternator is never a bad thing
> > to do. The question that has always plagued the OBAM aircraft
> > community continues to be: "Is cooling necessary?"
> >
> > Until we mount an effort to gather meaningful temperature data
> > internal to the alternator under various electrical loads and
> > flight conditions (hot-day, Vx climb), etc.
>snipped
> >
> > We know that very few OBAM aircraft will ever need all of
> > the alternator's nameplate power. We also know that cooling
> > effectiveness of air movement under the cowl can be strongly
> > influenced by changes in baffling, cowl geometry, accessory
> > locations, belt ratios, etc.
>snipped
> > In the past half-dozen or so seminars, I've offered to help
> > any interested builder in crafting a test plan and then
> > providing them with the data acquisition system that would
> > let us investigate alternator cooling issues on their
> > airplane. The same activity would work toward development of
> > a testing model and an article that might encourage others
> > to add further test data to the library. So far, no takers.
>snipped
> > Bob . . .
>
>Bob,
> Where would you suggest mounting a thermister on an alternator to
> monitor temperature?
>Charlie Kuss
If we were doing the typical full-up temperature survey on an
alternator in flight, a thermocouple would be attached to:
front bearing casting
rear bearing casting
diode commoning-plate/heat-sink(s)
. . . and finally a thermocouple wedged into
a stator winding slot.
The DAS would record all thermocouples in the
alternator + temperature of incoming cooling
air, oat and probably one cht slot. This would
be a total of 8 or 9 devices. Temperatures would
be recorded about once every 2 seconds. I'd also
consider adding a couple of absolute pressure
transducers for Palt and Ptotal.
We would also record alternator load (I have some
precision servoed hall-effect sensors that are easy
to install over the b-lead). If this were a certification
effort, we'd have to install a load bank to load the
machine to nameplate rated output. However, getting
three sets of data at min, max and some intermediate
load generated by your on-board systems is generally
sufficient to extrapolate max load conditions with
fair accuracy.
Lots of hardware but stuff I keep in inventory
(my shop is the last of the 'skunk werks' left at
RAC). The laptop is a klunky ol' dos machine
running a Power Basic utility that queries two
A/D converters modules and writes comma-delimited
text files to disk that can be easily sucked into
Excel for plotting and analysis.
It's easy to set in the right seat, start recording
process and forget it until after shutdown. Just
keep a time of day log of flight conditions to be
achieved as part of a test plan.
You game? We could make some real history here and
actually KNOW something about a typical OBAM alternator
installation.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: alternator health |
Hmmmm . . . I thought about this and I'm not sure that there's a
very good return on investment. An alternator is like prop-governor
or fuel pump, it's either working or it isn't. It's a really good
idea to see how hot you're getting under worst case conditions as-installed
and if those numbers don't make you mess yer drawers, then it's
unlikely that any form of instrumentation would give you an advance
warning of impending failure. The most likely scenario is that your
supper-whizzy alternator watch-dog will bark the same time the low-voltage
warning light comes on.
Now, if a builder was interested in monitoring how close the alternator
is to being maxed-out for present loads -AND- RPM the simple field voltage
tap I've described in the Z-figures is a good thing to watch.
Most alternators on Lycomings run a field voltage of less than 8 volts
even at max load while in cruise conditions. Anything over 8 volts
says that you might have a stator lead or a diode opening thus crippling
the alternator.
I helped chase a rat out of a Falco's alternator system a couple of years
ago. We
put a temporary field voltmeter wire on the alternator and strung it
back to the cabin by taping it to the outside of the airplane. It took
about ten minutes in flight to observe field voltage surging upward at
the same time the loadmeter was going down. This told us that the brushes
were intermittent. On teardown, the brushes were not worn but one of them
would hang up in the holder due to some kind of gucky on the side of the
brush that didn't get tacky and troublesome until the alternator was warmed
up and subject to engine vibration at the same time. Several bench tests
at the parts store failed to spot the problem.
Bob . . .
>
>
>On Jul 6, 2006, at 2:35 PM, Hinde, Frank George (Corvallis) wrote:
>
>>(Corvallis)"
>>
>>Just suck the data into an engine monitor like a Dynon and set an
>>alarm
>>on each parameter.
>
>The only problem with that is, at least in the case of field voltage
>or field current, it varies all over the map. It is proportional to
>load (goes up when load is increased) and inversely proportional to
>RPM (goes down as RPM increases). This means you have to know what
>both the load and the RPM are doing to make sense of the field
>voltage reading. I suspect that people will poke at the button and
>get a feel for what the field voltage should be in cruise with a
>normal load. If it jumps up then they will know that something has
>changed in their alternator. This is not something you can set a hard
>limit on.
>
>BTW, Bob, I want one in a 24V flavor too. Maybe we should just use a
>4-digit DVM.
>
>Brian Lloyd 361 Catterline Way
>brian-yak AT lloyd DOT com Folsom, CA 95630
>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
>I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
>--
>
>
>-- incoming mail is certified Virus Free.
>Checked by AVG Anti-Virus.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 6, 2006, at 11:01 PM, Robert L. Nuckolls, III wrote:
> If we were doing the typical full-up temperature survey on an
> alternator in flight, a thermocouple would be attached to:
>
> front bearing casting
> rear bearing casting
> diode commoning-plate/heat-sink(s)
> . . . and finally a thermocouple wedged into
> a stator winding slot.
You know, the marine and RV alternator guys have solved these
problems. I bet they have some good data.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: alternator health |
>
>I'll second that motion ....
>It'll make trouble shooting easier.
>Jerry Grimmonpre'
>Do no archive
>
>
>Bob, I loved your original alternator health-O-meter. How about a new
>one that measures:
>
>1. alternator load;
>2. alternator voltage;
>3. field voltage;
>4. alternator frame temperature;
>
>all in a single, compact, 2.25" instrument.
We could program a version of the AEC9011 to
watch load (hall effect sensor), field voltage
and temperature and light a warning light.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Re: Alternator Belt |
I know some Piper owners have received belt from Piper dealer in a Gates
sleeve, with the Gates number on the belt, and the Piper number hand
written in silver pen on the belt. I don't know for sure that it was an
automotive number, but believe that is correct. 9335XL Green Stripe or
9335HD. Piper number 73965-015 formerly #452-541
James H Nelson wrote:
>
> Charlie,
> I sell V-Belts for a living and other assorted sundry for
> industrial items like bearings. There is two styles of "V" belts. one
> configuration is "industrial" and the other is "automotive". The
> difference is in the angle that makes the v-belt. The automotive is a
> narrow "V" and the industrial "V" is a wider angle "V".. Industrial
> belts are designated by their size. The first letter or number usually
> designates the top width. Such as A-35 belt. This is a 1/2" wide belt
> that is 35" in circumference on the inside. A 4L370 is physically the
> same just a light duty "A" series. (don't ask !!) Think of the "L"
> meaning light duty. There is a series called "3V or 3VX that is almost
> the exact match to the belts used on aircraft engines. I will bring
> home a 3vx belt and check it out on my engine. That should put the
> confusion and sources to rest.
>
>
> Jim Nelson
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "DEAN PSIROPOULOS" <dean.psiropoulos(at)verizon.net> |
| Subject: | VM-1000 current sensor question |
I've been looking at this VM1000 current sensor (it looks like some sort of
hall effect sensor with 4 terminals, it's a coil you slide over the wire, no
connection needed). Originally I had it on the feed line from the alternator
but realized that I would only get readings of zero and greater than zero on
the display if I did that. So I thought I'd put it around the fat wire that
connects to the battery positive terminal and get both discharge and charge
readings. But....re-reading the VM-1000 manual and looking at their display
silk-screening, it appears that the display is only designed to read a
positive rate of charge from the alternator (0 to +60 amps). I don't have
everything connected yet so I can't actually fire it up and test it.
You VM1000 users, is this true? Does it NOT read and display negative
amperes when the battery is discharging and the alternator is not running
(or failed)? Is everyone installing this sensor on the alternator feed line
or are some of you doing something else??? if so what???? and why? Thanks.
Dean Psiropoulos
RV-6A N197DM
Plodding along to blissful completion.
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator Belt |
In a message dated 7/6/06 9:17:59 AM Eastern Daylight Time, nuckollsr(at)cox.net
writes:
> There's no such thing as an "aircraft alternator belt". There
> are thousands of belts by hundreds of manufacturers and they
> range in SERVICE LIFE from mediocre to the best-we-know how
> to do.
======================================
Don't tell that to the FAA!
Here are the part numbers:
ALT BELT: 37A19773-37 <--- FAA Approved and with an FAA - PMA stamp. This
is the Gates Automotive equivalent: (gates belt 3V375).
Now, as I have stated before, there are quality differences. I have noted
that when it comes to Original Timing Belts and Serpentine Belts. The FACTORY
ORIGINAL is of much better quality than OEM or Auto Store items. See my long
post with explanation ... It should be in the archives.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: VM-1000 current sensor question |
I'm in a similar situation as Dean - except I have most of my electrical
system up and functioning. My amp sensor is in the equivalent place of the
feed line and could only show current being generated by the alternators.
My instruction manual shows the 'minus' bar on the display page implying
that the unit could display current draw and supply - but I can't figure out
how to wire it so both situations would be discernable to the
transducer......the only solutions that I have come up with involve A) two
wires passing throught the transducer - one 'flowing' in each
direction...under normal operation one would carry generated current - under
failure operation (of the alternators) the other would carry drawn current
or B) two transducers with a switch to select which one is being
displayed...one transducer would show the generated current and the other
would show drawn current.
The VM1000 instruction manual indicates that the transducer is to be placed
to measure generated current from what I remember reading and does not
provide for reading of drawn current - even though the unit is implied to be
able to display either mode.
Maybe we need to get Vision Microsystems to weigh in n this one.....I'll
send out a note to them.....
Ralph Capen
----- Original Message -----
Sent: Friday, July 07, 2006 1:43 AM
>
>
> I've been looking at this VM1000 current sensor (it looks like some sort
> of
> hall effect sensor with 4 terminals, it's a coil you slide over the wire,
> no
> connection needed). Originally I had it on the feed line from the
> alternator
> but realized that I would only get readings of zero and greater than zero
> on
> the display if I did that. So I thought I'd put it around the fat wire
> that
> connects to the battery positive terminal and get both discharge and
> charge
> readings. But....re-reading the VM-1000 manual and looking at their
> display
> silk-screening, it appears that the display is only designed to read a
> positive rate of charge from the alternator (0 to +60 amps). I don't have
> everything connected yet so I can't actually fire it up and test it.
>
> You VM1000 users, is this true? Does it NOT read and display negative
> amperes when the battery is discharging and the alternator is not running
> (or failed)? Is everyone installing this sensor on the alternator feed
> line
> or are some of you doing something else??? if so what???? and why?
> Thanks.
>
>
> Dean Psiropoulos
> RV-6A N197DM
> Plodding along to blissful completion.
>
>
>
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | pulse width module |
Charlie,
"Jerry,
I scanned the first page of the assembly sheet for the MPJA pulse
width controller. See
http://www.mpja.com/productview.asp?product=4057+MD
I've sent it to you off list. The first unit took 1.5 hours to build.
(reading and understanding the instructions) "
I tried your source for which my thanks. Unfortunately they are
unaware that 'alien' beings can pay from away but ship internally. For some
obscure reason your dental Xrays must co-ordinate with your shoe size or
they won't deign to sell (VISA is actually good in several townships). So
much for NAFTA - remember "free" trade?
Anyway, when they grow up I'll buy.
But thanks for the trouble.
Ferg Kyle
Europa A064 914 Classic
________________________________________________________________________________
| From: | "Jerry & Ledy Esquenazi" <jlinga(at)mchsi.com> |
| Subject: | Re: VM-1000 current sensor question |
Guys,
When I installed my VM1000C, I had the same question and called the
company. The display will not show negative numbers. The current
sensor is designed to be used as a loadmeter and not a battery ammeter.
The voltage will generally give you a good indication whether or not the
battery is charging.
Jerry
I'm in a similar situation as Dean - except I have most of my electrical
system up and functioning. My amp sensor is in the equivalent place of
the
feed line and could only show current being generated by the
alternators.
My instruction manual shows the 'minus' bar on the display page implying
that the unit could display current draw and supply - but I can't figure
out
how to wire it so both situations would be discernable to the
transducer......the only solutions that I have come up with involve A)
two
wires passing throught the transducer - one 'flowing' in each
direction...under normal operation one would carry generated current -
under
failure operation (of the alternators) the other would carry drawn
current
or B) two transducers with a switch to select which one is being
displayed...one transducer would show the generated current and the
other
would show drawn current.
The VM1000 instruction manual indicates that the transducer is to be
placed
to measure generated current from what I remember reading and does not
provide for reading of drawn current - even though the unit is implied
to be
able to display either mode.
Maybe we need to get Vision Microsystems to weigh in n this one.....I'll
send out a note to them.....
Ralph Capen
----- Original Message -----
Sent: Friday, July 07, 2006 1:43 AM
>
>
> I've been looking at this VM1000 current sensor (it looks like some
sort
> of
> hall effect sensor with 4 terminals, it's a coil you slide over the
wire,
> no
> connection needed). Originally I had it on the feed line from the
> alternator
> but realized that I would only get readings of zero and greater than
zero
> on
> the display if I did that. So I thought I'd put it around the fat
wire
> that
> connects to the battery positive terminal and get both discharge and
> charge
> readings. But....re-reading the VM-1000 manual and looking at their
> display
> silk-screening, it appears that the display is only designed to read a
> positive rate of charge from the alternator (0 to +60 amps). I don't
have
> everything connected yet so I can't actually fire it up and test it.
>
> You VM1000 users, is this true? Does it NOT read and display negative
> amperes when the battery is discharging and the alternator is not
running
> (or failed)? Is everyone installing this sensor on the alternator
feed
> line
> or are some of you doing something else??? if so what???? and why?
> Thanks.
>
>
> Dean Psiropoulos
> RV-6A N197DM
> Plodding along to blissful completion
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator failure thoughts |
>
>On Jul 6, 2006, at 11:01 PM, Robert L. Nuckolls, III wrote:
>
>> If we were doing the typical full-up temperature survey on an
>> alternator in flight, a thermocouple would be attached to:
>>
>> front bearing casting
>> rear bearing casting
>> diode commoning-plate/heat-sink(s)
>> . . . and finally a thermocouple wedged into
>> a stator winding slot.
>
>You know, the marine and RV alternator guys have solved these
>problems. I bet they have some good data.
Don't understand "problem" . . . the goal is to confirm
the influence of the installation in a particular airplane.
If you have an off-the-shelf alternator in hand, the hardware
has already been crafted to meet design goals that are generally
confirmed independently of the installation.
A typical installation study for the purpose of acquiring
a TC or STC involves looking at the same points of interest
as-installed as the manufacturer of the alternator looked
at during their laboratory qual testing and making sure that
installed stresses are not alarmingly greater than those
encountered during qualification.
People have killed perfectly good hardware by not understanding
and accommodating it's limits in a new installation.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Battery Contactor - HOT... |
Go for it Marty.
I don't see how you can harm anything as long as you don't have any bare
wires hanging there that might short. Was there some particular concern
that you had?
Ken
Marty Martin wrote:
>
>
> I have wing tip (3 light, white, (red or greed) & strobe. I'm putting
> the firewall together, no engine to rehang as this was a flying Q200
> to begin with.
>
> I woundering if I can just connect the battery to the leads that go to
> the battery and check the lights for working condition.
>
> Maybe I need to wait and rehang the motor.
>
> Please let me know.
>
>
> Greg Martin, martygmartin(at)gmail.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: VM-1000 current sensor question |
>
>
>I've been looking at this VM1000 current sensor (it looks like some sort of
>hall effect sensor with 4 terminals, it's a coil you slide over the wire, no
>connection needed). Originally I had it on the feed line from the alternator
>but realized that I would only get readings of zero and greater than zero on
>the display if I did that.
Correct. It becomes an alternator LOADMETER
> . . . So I thought I'd put it around the fat wire that
>connects to the battery positive terminal and get both discharge and charge
>readings.
That becomes a BATTERY AMMETER which is less useful. While
it was the ONLY instrumentation in most automobiles and many
airplanes, it wasa system health instrument that required
interpretation and flight to flight trend monitoring. It met
FAA requirements for electrical system health monitoring.
The problem with a battery ammeter is that it "sorta" tells you if
the bus voltage is okay when the recharge current ultimately goes
back to zero AFTER it sorta tells you that the battery is okay when
it accepts a healthy recharge after engine start. Battery ammeters
are better than nothing but not much. Given that the VM-1000 provides
voltage readings and low volts warning, then using the ammeter function
to watch alternator load is the most definitive use of the instrument
for troubleshooting.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Battery Contactor - HOT... |
Didn't get to this one earlier. Battery contactors routinely run too hot
to touch but not too hot to operate properly. See:
http://www.aeroelectric.com/Pictures/Contactors/Battery_Contactor_Temps_1.jpg
http://www.aeroelectric.com/Pictures/Contactors/Battery_Contactor_Temps_2.jpg
Bob . . .
>
>Go for it Marty.
>I don't see how you can harm anything as long as you don't have any bare
>wires hanging there that might short. Was there some particular concern
>that you had?
>Ken
>
>Marty Martin wrote:
>
>>
>>
>>I have wing tip (3 light, white, (red or greed) & strobe. I'm putting
>>the firewall together, no engine to rehang as this was a flying Q200 to
>>begin with.
>>
>>I woundering if I can just connect the battery to the leads that go to
>>the battery and check the lights for working condition.
>>
>>Maybe I need to wait and rehang the motor.
>>
>>Please let me know.
>>
>>
>>Greg Martin, martygmartin(at)gmail.com
>
>
>--
>
>
>-- incoming mail is certified Virus Free.
>Checked by AVG Anti-Virus.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Alternator failure thoughts |
On Jul 7, 2006, at 8:37 AM, Robert L. Nuckolls, III wrote:
>> You know, the marine and RV alternator guys have solved these
>> problems. I bet they have some good data.
>
>
> Don't understand "problem" . . . the goal is to confirm
> the influence of the installation in a particular airplane.
Perhaps problem is not the right word. Knowing maximum safe operating
temperature, temp rise with load, etc., would help someone plan their
installation better than just bolting it in there an hoping it works.
> People have killed perfectly good hardware by not understanding
> and accommodating it's limits in a new installation.
Right. And what are those limits and how can we mitigate?
OTOH, most alternators work just fine so maybe just ignoring the few
failures is acceptable.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Alternator failure thoughts |
>To: aeroelectric-list(at)matronics.com
>From: Charlie Kuss <chaztuna(at)adelphia.net>
>Date: Thu, 06 Jul 2006 22:31:35 -0400
>Subject: Re: AeroElectric-List: Alternator failure thoughts
>Sender: owner-aeroelectric-list-server(at)matronics.com
>Reply-To: aeroelectric-list(at)matronics.com
>
>At 06:57 AM 7/5/2006, you wrote:
>>In a message dated 7/4/2006 9:25:44 PM Eastern Standard Time,
>>chaztuna(at)adelphia.net writes:
>>For the purposes of the alternators we use, the rectifier is
>>comprised of 6 diodes. These diodes can fail in two modes, open or
>>short. Failing open (diode blows apart) is the more common
>>failure mode. In this mode, each diode that fails will reduce the
>>alternator's output by 1/6th.
>>Charlie,
>>
>>Charlie:
>>
>>Why 6 diodes? Half wave rectification only requires 2 diodes. And
>>Full wave reverification only requires 4 diodes. So why 6 and how
>>are they hooked up?
>>
>>Barry
>>"Chop'd Liver"
>
>Barry,
> The ND alternators actually DO have 8 diodes. 6 of these rectify
> the AC current from the 3 windings of the stator into DC current.
> The main function of the other two diodes is to prevent the battery
> from discharging back into the alternator when the engine is not
> running. You have to remember that a DC motor and a generator are
> very similar. You apply current into a motor to create mechanical
> motion. With a generator (or alternator in this case) you apply
> mechanical motion and a magnetic field to create electrical current.
> If either of these two isolation diodes were to fail short, the
> battery would discharge into the alternator. The alternator would
> act like a seized motor. The input current from the battery can
> not turn over the engine, via the alternator's pulley and drive belt.
> Have you ever had a vehicle which operated OK when driven daily.
> Yet, if allowed to sit unused for a number of days, the vehicle
> would have a dead battery? Shorted isolation diodes in the
> alternator are one possible cause of this situation.
>Charlie Kuss
Barry & Listers,
(Voice of Auggie Doggie) Oh, the shame of it all! I really stepped
in deep doo doo on the post above. Please ignore it, as it's all
incorrect. Brian's earlier post (which I hadn't read) correctly
described the function of the 2 extra diodes.
My apologizes
Charlie Kuss
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | VM-1000 current sensor question |
7/7/2006
Responding to an AeroElectric-List message previously posted by: "DEAN
PSIROPOULOS"
Hello Dean, Why don't you just shoot an email to Vision Microsystems
support(at)visionmicrosystems.com or, better
yet, call them on the phone, (360-714-8203) ask for a technician and ask
him. I have found them great people to deal with. Please tell us what you
learn.
My sensor is on the output (B lead) from the alternator. My visual
electrical information consists of that VM 1000 display reading of amperage
being put out by the alternator, the VM 1000 display of bus voltage, and a
low voltage warning light from a B&C LR3 voltage regulator. The VM 1000
display amperage reading is zero until the alternator comes on line.
Isn't the above a sufficient display of electrical information?
I guess it would be nice to be able to know at all times what amount of the
electrical supply to the aircraft systems was coming from the battery and
what amount was coming from the alternator, but I don't know just exactly
how one would go about configuring a system to obtain that information or
how one would use that information.
I think that after the engine is started and the alternator is on line that
all of the aircraft's electrical system needs are being supplied by the
alternator and if the battery needs charging as determined by the voltage
regulator then the alternator is also supplying the amperage that flows into
the battery.The only time the battery should be discharging is if the total
amperage required by aircraft systems and battery charging needs is greater
than the output capacity of the alternator. Can some one help me here?
OC
PS: I did find the VM hall effect sensor difficult to mount. Their
directions to put it into some sort of protective box was too awkward for me
so mine is just bolted to a bracket on the forward side of the fire wall.
Has worked OK for 144 hours.
"DEAN PSIROPOULOS WRITES"
> I've been looking at this VM1000 current sensor (it looks like some sort
> of
> hall effect sensor with 4 terminals, it's a coil you slide over the wire,
> no
> connection needed). Originally I had it on the feed line from the
> alternator
> but realized that I would only get readings of zero and greater than zero
> on
> the display if I did that. So I thought I'd put it around the fat wire
> that
> connects to the battery positive terminal and get both discharge and
> charge
> readings. But....re-reading the VM-1000 manual and looking at their
> display
> silk-screening, it appears that the display is only designed to read a
> positive rate of charge from the alternator (0 to +60 amps). I don't have
> everything connected yet so I can't actually fire it up and test it.
>
> You VM1000 users, is this true? Does it NOT read and display negative
> amperes when the battery is discharging and the alternator is not running
> (or failed)? Is everyone installing this sensor on the alternator feed
> line
> or are some of you doing something else??? if so what???? and why?
> Thanks.
>
>
> Dean Psiropoulos
> RV-6A N197DM
> Plodding along to blissful completion.
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: VM-1000 current sensor question |
I sent a note to Vision Microsystems....
I'll post the response.....
BTW, My understanding matches yours....about the alternator supplying required
current etc.....
Ralph
-----Original Message-----
>From: bakerocb(at)cox.net
>Sent: Jul 7, 2006 11:28 AM
>To: aeroelectric-list(at)matronics.com, dean.psiropoulos(at)verizon.net
>Subject: AeroElectric-List: VM-1000 current sensor question
>
>
>7/7/2006
>
>Responding to an AeroElectric-List message previously posted by: "DEAN
>PSIROPOULOS"
>
>Hello Dean, Why don't you just shoot an email to Vision Microsystems
>support(at)visionmicrosystems.com or, better
>yet, call them on the phone, (360-714-8203) ask for a technician and ask
>him. I have found them great people to deal with. Please tell us what you
>learn.
>
>My sensor is on the output (B lead) from the alternator. My visual
>electrical information consists of that VM 1000 display reading of amperage
>being put out by the alternator, the VM 1000 display of bus voltage, and a
>low voltage warning light from a B&C LR3 voltage regulator. The VM 1000
>display amperage reading is zero until the alternator comes on line.
>
>Isn't the above a sufficient display of electrical information?
>
>I guess it would be nice to be able to know at all times what amount of the
>electrical supply to the aircraft systems was coming from the battery and
>what amount was coming from the alternator, but I don't know just exactly
>how one would go about configuring a system to obtain that information or
>how one would use that information.
>
>I think that after the engine is started and the alternator is on line that
>all of the aircraft's electrical system needs are being supplied by the
>alternator and if the battery needs charging as determined by the voltage
>regulator then the alternator is also supplying the amperage that flows into
>the battery.The only time the battery should be discharging is if the total
>amperage required by aircraft systems and battery charging needs is greater
>than the output capacity of the alternator. Can some one help me here?
>
>OC
>
>PS: I did find the VM hall effect sensor difficult to mount. Their
>directions to put it into some sort of protective box was too awkward for me
>so mine is just bolted to a bracket on the forward side of the fire wall.
>Has worked OK for 144 hours.
>
>"DEAN PSIROPOULOS WRITES"
>
>> I've been looking at this VM1000 current sensor (it looks like some sort
>> of
>> hall effect sensor with 4 terminals, it's a coil you slide over the wire,
>> no
>> connection needed). Originally I had it on the feed line from the
>> alternator
>> but realized that I would only get readings of zero and greater than zero
>> on
>> the display if I did that. So I thought I'd put it around the fat wire
>> that
>> connects to the battery positive terminal and get both discharge and
>> charge
>> readings. But....re-reading the VM-1000 manual and looking at their
>> display
>> silk-screening, it appears that the display is only designed to read a
>> positive rate of charge from the alternator (0 to +60 amps). I don't have
>> everything connected yet so I can't actually fire it up and test it.
>>
>> You VM1000 users, is this true? Does it NOT read and display negative
>> amperes when the battery is discharging and the alternator is not running
>> (or failed)? Is everyone installing this sensor on the alternator feed
>> line
>> or are some of you doing something else??? if so what???? and why?
>> Thanks.
>>
>>
>> Dean Psiropoulos
>> RV-6A N197DM
>> Plodding along to blissful completion.
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: alternator failure modes |
In a message dated 7/5/06 7:32:46 PM Eastern Daylight Time,
brian-yak(at)lloyd.com writes:
> I have had several people write to me to tell me that they have never
> seen an alternator turn into a grenade. Neither have I. I was just
> listing that is a *possible* scenario, as in, "I suppose this might
> happen." I think it unlikely but I do think that things like broken
> brackets, having the alternator seize, and who knows what happens if
> both happen at once.
===========================
Brian:
When you say grenade, are you saying totally blown apart with the case
breaking into pieces?
I have done two alternators jobs that have had what I would call catastrophic
failures.
The first had the through bolts come out and the alternator bells separated.
This caused the rotor to violently wobble and destroy the stator. Basic
cause - Plane owner went to his buddy to have an annual done. Cost of Annual:
One
bottle of Jonnie Walker Black. I do not know at what point the bottle was
consumed.
Second was a failure of the alternator's end bell (sheave end) where the
bearing is pressed in. The voltage output failed and the rotor just started to
wobble off center. Basic cause - The alternator was installed off center. The
sheave was not aligned with the gear tooth ring.
I would not cal lit a grenade, but close.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
Hey Guys:
I've been thinking on this too much and wish for some outside input.
On a 4 cycle engine does the firing of one spark plug happen every other
revolution? That is from one Ignition on spark plug #1 to the next igination on
spark plug #1 the crank goes around two (2) times?
Does this sound correct?
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: 4 cycle - cycle |
On Jul 7, 2006, at 3:05 PM, FLYaDIVE(at)aol.com wrote:
>
> Hey Guys:
>
> I've been thinking on this too much and wish for some outside input.
>
> On a 4 cycle engine does the firing of one spark plug happen every
> other
> revolution?
Yes.
> That is from one Ignition on spark plug #1 to the next igination on
> spark plug #1 the crank goes around two (2) times?
Yes.
>
> Does this sound correct?
Yes.
>
> Barry
> "Chop'd Liver"
>
>
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: alternator failure modes |
On Jul 7, 2006, at 3:04 PM, FLYaDIVE(at)aol.com wrote:
>
> In a message dated 7/5/06 7:32:46 PM Eastern Daylight Time,
> brian-yak(at)lloyd.com writes:
>
>> I have had several people write to me to tell me that they have never
>> seen an alternator turn into a grenade. Neither have I. I was just
>> listing that is a *possible* scenario, as in, "I suppose this might
>> happen." I think it unlikely but I do think that things like broken
>> brackets, having the alternator seize, and who knows what happens if
>> both happen at once.
> ===========================
> Brian:
>
> When you say grenade, are you saying totally blown apart with the case
> breaking into pieces?
Yes, that was the picture I had in my mind but really, any failure
where the energy in the rotor causes catastrophic failure of the
case. It could be just breaking off the mounting ears, bells
separating, etc.
>
> I have done two alternators jobs that have had what I would call
> catastrophic
> failures.
> The first had the through bolts come out and the alternator bells
> separated.
> This caused the rotor to violently wobble and destroy the stator.
> Basic
> cause - Plane owner went to his buddy to have an annual done. Cost
> of Annual: One
> bottle of Jonnie Walker Black. I do not know at what point the
> bottle was
> consumed.
Usually pre-inspection. That ensures that the signature appears in
the logbook regardless of the condition of the airplane.
> Second was a failure of the alternator's end bell (sheave end)
> where the
> bearing is pressed in. The voltage output failed and the rotor
> just started to
> wobble off center. Basic cause - The alternator was installed off
> center. The
> sheave was not aligned with the gear tooth ring.
>
> I would not cal lit a grenade, but close.
That is pretty much what I was thinking. I could see the rotor
suddenly seizing because a bearing failed and the rotor jams with the
case or the stator. The sudden stoppage along with the additional
torque being applied by the belt could cause some or all of the
alternator to do the grand tour of the cowling. I can see that doing
damage to the carb, fuel injection servo, linkages, exhaust, airbox,
or other bits down there under the engine. I don't think it likely to
hole the case of the engine but weird stuff happens. OTOH, there is a
lot more mass in an alternator than in a piston or connecting rod. It
would not be a pretty sight.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Bob C. " <flyboy.bob(at)gmail.com> |
| Subject: | Re: VM-1000 current sensor question |
So Bob,
I hope this isn't too redundant, in this scenario, where is the best
(most useful) place to locate the hall effect sensor?
Thanks,
Bob Christensen
in SE Iowa - RV-8 Bldr
On 7/7/06, Robert L. Nuckolls, III wrote:
>
>
> >
> >
> >I've been looking at this VM1000 current sensor (it looks like some sort of
> >hall effect sensor with 4 terminals, it's a coil you slide over the wire, no
> >connection needed). Originally I had it on the feed line from the alternator
> >but realized that I would only get readings of zero and greater than zero on
> >the display if I did that.
>
> Correct. It becomes an alternator LOADMETER
>
>
> > . . . So I thought I'd put it around the fat wire that
> >connects to the battery positive terminal and get both discharge and charge
> >readings.
>
> That becomes a BATTERY AMMETER which is less useful. While
> it was the ONLY instrumentation in most automobiles and many
> airplanes, it wasa system health instrument that required
> interpretation and flight to flight trend monitoring. It met
> FAA requirements for electrical system health monitoring.
>
> The problem with a battery ammeter is that it "sorta" tells you if
> the bus voltage is okay when the recharge current ultimately goes
> back to zero AFTER it sorta tells you that the battery is okay when
> it accepts a healthy recharge after engine start. Battery ammeters
> are better than nothing but not much. Given that the VM-1000 provides
> voltage readings and low volts warning, then using the ammeter function
> to watch alternator load is the most definitive use of the instrument
> for troubleshooting.
>
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: VM-1000 current sensor question |
>
>So Bob,
>
>I hope this isn't too redundant, in this scenario, where is the best
>(most useful) place to locate the hall effect sensor?
>
>Thanks,
>Bob Christensen
>in SE Iowa - RV-8 Bldr
If it were my airplane (and I chose to have any ammeters
at all) they would be alternator loadmeters. This is the
most useful current measurement location for troubleshooting
a misbehaving alternator system.
Bob . . .
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: VM-1000 current sensor question |
On Jul 7, 2006, at 5:54 PM, Bob C. wrote:
>
>
> So Bob,
>
> I hope this isn't too redundant, in this scenario, where is the best
> (most useful) place to locate the hall effect sensor?
In the average electrical system there are three places to measure
current. If measure two you can calculate the third. The three places
are:
1. output of the alternator (B-lead);
2. battery positive terminal;
3. input to the main distribution bus.
If you know what is coming out of the alternator and what is going
into the loads then the difference is what is going into or coming
out of the battery.
If you know what is coming out of the alternator and what is going
into the battery, the difference is going into your loads.
If you know what is going into the battery and what is going into
your loads, add them together to figure out alternator load.
If I could only measure one I would measure alternator load and, of
course, system voltage. You will quickly learn what your loads draw
and what the battery draws will drop near to zero. Any excess load on
the alternator indicates a problem.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| Subject: | RE: Insrument Lighting |
Jerry,
If you have a combination of incandescent and LEDs you can control the
brightness with a unit made by A and T labs. You can daisy-chain the modules
and control the overall brightness with a master. Obviously it will also
level out different intensities of incandescenst. You can find them at
http://www.a-and-t-labs.com/
Peter
_____
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jerry &
Ledy Esquenazi
Sent: Wednesday, July 05, 2006 10:52 PM
Hey Guys,
Thanks to Eric, Ken , and Charlie for your suggestions. However, I
don't have any idea on how to build a PWM or variable duty cycle circuit.
Do you guys have any schematics or more info? Thanks Charlie for including
the link.
I don't plan on disconnecting the instrument or covering it up. I have
the g-meter lit for aesthetics and symmetry. I paid extra to have it lit,
so I plan on using it.
I called the manufacturer of the g-meter. The reason the instrument is
so bright is that it actually has three bulbs drawing a total of 0.56. The
company verified my amp draw correct for a 12 v unit. So at least I know I
have the right bulbs. I still need to dim it down a bit to make the
brightness similar to the rest of the instruments. Bob K., do you have any
ideas?
Thank you,
Jerry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: 4 cycle - cycle |
In a message dated 7/7/06 3:32:15 PM Eastern Daylight Time,
frank.hinde(at)hp.com writes:
> Yup!
>
> Suck...push...bang...Blow
>
> Two rotations
>
> Frank
======================
LoL ... Thank you Frank, I like you r description.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: 4 cycle - cycle |
In a message dated 7/7/06 3:50:38 PM Eastern Daylight Time,
brian-yak(at)lloyd.com writes:
> > Hey Guys:
> >
> > I've been thinking on this too much and wish for some outside input.
> >
> > On a 4 cycle engine does the firing of one spark plug happen every
> > other
> > revolution?
>
> Yes.
>
> > That is from one Ignition on spark plug #1 to the next igination on
> > spark plug #1 the crank goes around two (2) times?
>
> Yes.
>
> >
> > Does this sound correct?
>
> Yes.
>
> >
> > Barry
> > "Chop'd Liver"
===========================
Thank you Brian for the conformation.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: 4 cycle - cycle |
On Jul 7, 2006, at 11:39 PM, FLYaDIVE(at)aol.com wrote:
>
> In a message dated 7/7/06 3:50:38 PM Eastern Daylight Time,
> brian-yak(at)lloyd.com writes:
>
>>> Hey Guys:
>>>
>>> I've been thinking on this too much and wish for some outside input.
>>>
>>> On a 4 cycle engine does the firing of one spark plug happen every
>>> other
>>> revolution?
>>
>> Yes.
>>
>>> That is from one Ignition on spark plug #1 to the next igination on
>>> spark plug #1 the crank goes around two (2) times?
>>
>> Yes.
>>
>>>
>>> Does this sound correct?
>>
>> Yes.
>>
>>>
>>> Barry
>>> "Chop'd Liver"
> ===========================
> Thank you Brian for the conformation.
Welcome. ;-)
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: RE: Insrument Lighting |
Morning, Peter...
>>www.a-and-t-labs.com/ <http://www.a-and-t-labs.com/><<
Great website! Not only do they sell the kits, or just the PC board (the
parts list states that they are all available at Digi-Key), but they
have the complete circuit description, block diagrams, schematic
diagrams and all the artwork for a PC board on the site for those who
want to home brew it!
Note that the dimmer also has a photocell option to turn on the lights
when the cockpit gets too dark. Looks like they thought of
everything...good link, thanks, Peter.
Harley Dixon
------------------------------------------------------------------------
Peter Laurence wrote:
>
> Jerry,
>
>
>
> If you have a combination of incandescent and LEDs you can control the
> brightness with a unit made by A and T labs. You can daisy-chain the
> modules and control the overall brightness with a master. Obviously it
> will also level out different intensities of incandescenst. You can
> find them at http://www.a-and-t-labs.com/
>
>
>
>
>
> Peter
>
>
>
> ------------------------------------------------------------------------
>
> *From:* owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] *On Behalf Of
> *Jerry & Ledy Esquenazi
> *Sent:* Wednesday, July 05, 2006 10:52 PM
> *To:* AeroElectric-List(at)matronics.com
> *Subject:* AeroElectric-List: RE: Insrument Lighting
>
>
>
> Hey Guys,
>
> Thanks to Eric, Ken , and Charlie for your suggestions. However,
> I don't have any idea on how to build a PWM or variable duty cycle
> circuit. Do you guys have any schematics or more info? Thanks
> Charlie for including the link.
>
> I don't plan on disconnecting the instrument or covering it up. I
> have the g-meter lit for aesthetics and symmetry. I paid extra to
> have it lit, so I plan on using it.
>
> I called the manufacturer of the g-meter. The reason the
> instrument is so bright is that it actually has three bulbs drawing a
> total of 0.56. The company verified my amp draw correct for a 12 v
> unit. So at least I know I have the right bulbs. I still need to dim
> it down a bit to make the brightness similar to the rest of the
> instruments. Bob K., do you have any ideas?
>
>
>
> Thank you,
>
> Jerry
>
>
>
________________________________________________________________________________
| From: | "George Braly" <gwbraly(at)gami.com> |
| Subject: | alternator failure modes |
I have had an alternator turn into a hunk of twisted junk due to a
failed bearing.
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
FLYaDIVE(at)aol.com
Sent: Friday, July 07, 2006 2:04 PM
In a message dated 7/5/06 7:32:46 PM Eastern Daylight Time,
brian-yak(at)lloyd.com writes:
> I have had several people write to me to tell me that they have never
> seen an alternator turn into a grenade. Neither have I. I was just
> listing that is a *possible* scenario, as in, "I suppose this might
> happen." I think it unlikely but I do think that things like broken
> brackets, having the alternator seize, and who knows what happens if
> both happen at once.
===========================
Brian:
When you say grenade, are you saying totally blown apart with the case
breaking into pieces?
I have done two alternators jobs that have had what I would call
catastrophic
failures.
The first had the through bolts come out and the alternator bells
separated.
This caused the rotor to violently wobble and destroy the stator. Basic
cause - Plane owner went to his buddy to have an annual done. Cost of
Annual: One
bottle of Jonnie Walker Black. I do not know at what point the bottle
was
consumed.
Second was a failure of the alternator's end bell (sheave end) where the
bearing is pressed in. The voltage output failed and the rotor just
started to
wobble off center. Basic cause - The alternator was installed off
center. The
sheave was not aligned with the gear tooth ring.
I would not cal lit a grenade, but close.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: RE: Insrument Lighting |
In a message dated 7/8/06 7:52:41 AM Eastern Daylight Time,
harley(at)AgelessWings.com writes:
> Note that the dimmer also has a photocell option to turn on the lights
> when the cockpit gets too dark. Looks like they thought of
> everything...good link, thanks, Peter.
>
> Harley Dixon
>
======================
Hey Guys ...
Are you really willing to spend $75 for a simple dimmer? As I stated before,
as much as I dislike Radio Shack you can build this dimmer for $15 to $20
with all parts and instructions available from the $hit Shack.
LQQK for the LM-317
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: RE: Insrument Lighting |
FLYaDIVE(at)aol.com wrote:
>
> In a message dated 7/8/06 7:52:41 AM Eastern Daylight Time,
> harley(at)AgelessWings.com writes:
>
>
>> Note that the dimmer also has a photocell option to turn on the lights
>> when the cockpit gets too dark. Looks like they thought of
>> everything...good link, thanks, Peter.
>>
>> Harley Dixon
>>
>>
> ======================
> Hey Guys ...
>
> Are you really willing to spend $75 for a simple dimmer? As I stated before,
> as much as I dislike Radio Shack you can build this dimmer for $15 to $20
> with all parts and instructions available from the $hit Shack.
>
> LQQK for the LM-317
>
> Barry
> "Chop'd Liver"
>
Morning, Barry (or, are we supposed to call you Chop'd Liver? )...
>>spend $75 for a simple dimmer?<<
That's why I supported Peter's choice of that link...the web site
doesn't limit one to purchasing their unit. It has a complete
schematic, block diagram, parts list, etc..., and mentions that all the
parts can be purchased from Digi-key...but, of course, one can buy them
wherever you'd like, Radio Shack not excluded. Mouser being my first choice.
The PDF for the description and schematic for it is here:
www.a-and-t-labs.com/K11_Dimmer/Dimmer_with_figs.pdf
Includes instructions for construction on a perf board, or a pc board
which you can make yourself from their artwork or buy from them and add
the parts, installation instructions, etc.
Their feature list in the above document says:
Multiple outputs with tracking capability
Day time full brightness over-ride capability
Reliability
Current limiting/short circuit protection
Thermal protection
Low drop-out voltage (ability to adjust the dimmer bus up as close to
the battery
voltage as possible)
Photocell light sensor automatic control capability
Low cost
A little more than the Radio shack dimmer.
It's beginning to sound like I'm affiliated with A&T Labs in some
way...I assure you, I am not. I just appreciate a company that offers
the option to build or buy...and makes nothing off of it if you build.
After all, that's why I have a Long EZ .
Harley
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: RE: Insrument Lighting |
In a message dated 7/8/06 9:44:29 AM Eastern Daylight Time,
harley(at)AgelessWings.com writes:
> Morning, Barry (or, are we supposed to call you Chop'd Liver? )...
>
Harley:
You can call me Barry
You can call me Chop'd Liver
You can call me Gimp
But don't call me Johnson!
Chop'd Liver and Gimp are my Callsigns. Flight callsign is NUGGET
If I'm working ATC then it is NUGGET 01
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Ben Schneider <plumberben(at)yahoo.com> |
| Subject: | Note #10 on Z-12 |
Bob,
I was putting together my contactors, current limiters, and shunts via Z-12.
My question comes in with the current limiter near the starter contactor.
I m using an auto conversion, and using an automotive starter with a solenoid
on the starter. Mounting the CL near the starter does not really work out for
me. The note in the aeroelectric bible says "Consider installing the breaker
(or fuse) as close as possible to the starter contactor" Can you elaborate?
Is it an alternator noise issue? Is it going to cause me grief in the future?
The CL will be on the firewall, and the starter and soleoid will be right
up near the prop about 24 inches away. Is that going to cause me issues, other
that running big wire up there?
Just wanting to fully understand.
Ben Schneider
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Collins Radio Request |
I have a friend seeking to find a source for a Collins 350A Nav unit.
Any help will be very appreciated.
Jim McCulley
---------------------------------------------------------------------
________________________________________________________________________________
| From: | gary.stiffler(at)kroger.com |
Hi:
I have a 1974 Grumman AA1B. Mounted on the firewall are two cylinders
about one inch in diameter, one is about an inch in length with a =BC 20
post on either end and the alternator charging circuit passes through
it.
One of the posts is cross threaded and moves inside of the cylinder. The
other is electrically between the solid state regulator and the
alternator. It had a ground wire which looks like 16 gauge that is no
longer attached running in to the bakelite on one end of the cylinder.
Does anyone know what these devices are and where I can get
replacements?
Gary
N952GS
________________________________________________________________________________
| From: | "Deems Herring" <dsleepy47(at)hotmail.com> |
I have a 1776 AA1B, it sounds to me like you are talking about the starter
and battery relays. Check here: http://www.fletchair.com/ check page 12 of
there pdf catalog for a picture. I recommend Fletchair for all things Grumm
an you can reach them at 1 800 FA-WINGS.
Deems Herring
AA1B N1491R
Hi:
I have a 1974 Grumman AA1B. Mounted on the firewall are two cylinders about
one inch in diameter,
_________________________________________________________________
Express yourself: design your homepage the way you want it with Live.com.
http://www.live.com/getstarted
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Insrument Lighting |
An instrument with internal tungsten lamps should be easy to convert to LEDs. This
has many benefits, and the LEDs are available in exact replacement sizes.
(Ledtronics and others places).
I sell the "Extremely General Purpose Adjustable Voltage Regulator" that is used
for dimming purposes and is smaller and lighter than anything you could build
from a kit. For $99 for four of them, it's hard to beat the price. too. Share
them with a fellow builder.
--------
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=45967#45967
Attachments:
http://forums.matronics.com//files/egpavr_161.pdf
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
In a message dated 7/9/06 7:30:44 PM Eastern Daylight Time,
gary.stiffler(at)kroger.com writes:
> Hi:
>
>
>
> I have a 1974 Grumman AA1B. Mounted on the firewall are two cylinders
> about one inch in diameter, one is about an inch in length with a 20
> post on either end and the alternator charging circuit passes through it.
> One of the posts is cross threaded and moves inside of the cylinder. The
> other is electrically between the solid state regulator and the
> alternator. It had a ground wire which looks like 16 gauge that is no
> longer attached running in to the bakelite on one end of the cylinder.
> Does anyone know what these devices are and where I can get replacements?
>
>
>
> Gary
>
> N952GS
===========================
Gary:
As you have guess and from your description they are FEED-THROUGH Capacitors.
Their value is probably in the range of .001 to .01 uF at 20 VDC (WVDC) or
more. The voltage should be MORE than the system voltage by 50% and if you
find one at 100 VDC (WVDC) you can use that also ... Not critical.
I'm not understanding your description about the other item. That sounds
like an Electrolytic capacitor (Polarized ... + & - leads) that is hooked between
the 'S' terminal of the ACU and Ground. It's purpose is to filter out NOISE
& Spikes. The value of that can be anywhere from say 25,000 uF to 200,000 uF
and of course the voltage rating should be as described above.
Hope this helps.
Hey Got pictures?
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "Jerry & Ledy Esquenazi" <jlinga(at)mchsi.com> |
| Subject: | Re: Instrument Lighting |
Hello Guys,
At the suggestion of another lister I googled the LM317K. It took
about $6 for the components and hour worth of work. I didn't even have
to go to Radio Shack; I have an excellent electronics supply store 5
minutes from the house. Not bad for a town of only 45,000! Anyway the
regulator works like a champ. The reason I needed this is because my
g-meter light was a lot brighter than the rest of the instruments. It
has a 3 lamps built into the instrument unlike the other instruments
that have a simple light tray. A simple resistor in series was getting
too hot.
Since my main control for my lights is the LC40 4 ch dimmer, I did
away with the pot in the LM317K circuit and replaced it with a fixed
resistor of appropriate size. The g-meter lighting is powered by the
LM317K circuit which in turn is wired to the rest of my instrument
lighting circuit via the LC40.
Try it. It is easy, cheap, and effective.
Jerry
Hey Guys ...
Are you really willing to spend $75 for a simple dimmer? As I stated
before,
as much as I dislike Radio Shack you can build this dimmer for $15 to
$20
with all parts and instructions available from the $hit Shack.
LQQK for the LM-317
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: 22000 MF Capacitor |
In a message dated 7/1/06 6:18:38 PM Eastern Daylight Time,
twalker(at)cableone.net writes:
> I'm wiring my Rotax 912 and I have the above capacitor. I can't understand
> the markings on the two terminals. one of the terminals has a dab of black
> paint on it and the other is clear. Can someone tell me what the polarity
> of these two terminals is/are?
>
> Many thanks,
>
> Tommy Walker in Alabama
==========================
Tommy:
Have you received the information you were looking for?
Sounds like you have an Electrolytic Capacitor. The 'MF' could also be
written as "uF' which is read as Micro-Farads. The Black is Ground and the Clear
is Positive. To verify this there should also be a voltage marking in the
range of 16 to 100 VDC maybe even higher.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | LM-317 dimmer (was: Instrument Lighting) |
The LM-317 is an adjustable *linear* voltage regulator. Think of it
as a power resistor that adjusts itself to always maintain the same
voltage at its output. By varying that voltage you can vary the
brightness of the lamps.
There is a drawback to this type of regulator; it must dissipate the
power represented by the voltage drop across the regulator (voltage
difference between the input and output). For example, if the input
is 14V and you have the output voltage set at about 50% (about 7
volts) for low-to-medium brightness for your lamps, and your lamps
draw about 1 amp, the regulator has to dissipate 7 watts ( [14V-7V] x
1A). Like the resistor it is going to get quite hot. You need to make
sure it has a good heat sink to get rid of the heat.
But if your lamp loads are low (perhaps you are using LED lighting)
then the LM-317 won't have to dissipate much power. It may be 30-year-
old technology but it does work pretty well.
This is where a variable switching regulator or a pulse-width-
modulator (PWM) is better. These devices dissipate very little heat
to achieve the same thing.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Mark Chamberlain" <mchamberlain(at)runbox.com> |
Hi All,
I am about to install the Dynon Ammeter Shunt that comes with the 180
FlightDeck. It can be installed in 3 locations that can read either:
1. Amps
in and out of battery (-60a to 60a),
2. Amps in to the battery from the alternator only
3. Amps used by aircraft load only.
My question is: where would be the best location to put it? Suggestions welcomed.
Thanks for your help,
Mark
RV-7 (234C Res)
Engine/Wiring
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Ahh...Therein lies the question.
I personally put it in the Alternator B lead. In fact I have 2
alternators so I purchased an extra shunt and put one in each b lead...I
used a changeover switch labelled amps#1 and Amps#2.
I use the SD8 as a backup and will simply flip the switch over to read
how the SD8 is performing compared to knowing how many amps it will make
at say 2600RPM.
Frank
-----Original Message-----
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark
Chamberlain
Sent: Monday, July 10, 2006 10:40 AM
-->
Hi All,
I am about to install the Dynon Ammeter Shunt that comes with the 180
FlightDeck. It can be installed in 3 locations that can read either:
1. Amps
in and out of battery (-60a to 60a),
2. Amps in to the battery from the alternator only 3. Amps used by
aircraft load only.
My question is: where would be the best location to put it? Suggestions
welcomed.
Thanks for your help,
Mark
RV-7 (234C Res)
Engine/Wiring
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Note #10 on Z-12 |
>Bob,
>
> I was putting together my contactors, current limiters, and shunts via
> Z-12. My question comes in with the current limiter near the starter
> contactor. I m using an auto conversion, and using an automotive starter
> with a solenoid on the starter. Mounting the CL near the starter does not
> really work out for me.
Then feed the alternator to the down-stream side of the battery
contactor and mount the limiter there . . .
> The note in the aeroelectric bible says "Consider installing the breaker
> (or fuse) as close as possible to the starter contactor" Can you
> elaborate? Is it an alternator noise issue?
No, it protects the altenrator b-lead which can tie into the system
at either the starter contactor or the battery contactor . . .
> Is it going to cause me grief in the future? The CL will be on the
> firewall, and the starter and soleoid will be right up near the prop
> about 24 inches away. Is that going to cause me issues, other that
> running big wire up there?
>
>Just wanting to fully understand.
No big deal. Use the alternate location.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: VM-1000 current sensor question |
This conversation has run far-afield . . .
Consider that as long as your low-volts warning light is OFF,
there is nothing helpful for aviating or navigating offered by any
display of amps in any part of the system. When the low volts
light does come on, it's wise to have "plan-b" in the hip pocket
for comfortable termination of flight, preferably at the airport
of intended destination. Again, whatever the amps display is saying
is not useful to the task at hand.
When it comes time to troubleshoot the system, there is no
single measurement point for amps that will minimize the efforts
needed to troubleshoot the system. The repair task almost always
requires probing the system for a LOT more data than what is
offered by panel displays.
I'll suggest there is no right, better, wrong, or best place to
put an ammeter sense point. Every one of the classic locations offers
some data that is useful only if you know the significance of the
data and how to interpret it. But using any such data in flight
for diagnosis is not a useful thing to do . . . it's never helpful
for comfortably completing the flight. No matter where you choose
to put the sense point(s), they will be only the beginning of a
future troubleshooting effort.
Bob . . .
________________________________________________________________________________
| Subject: | Wingtip Grounding |
Hi folks,
I am getting towards completion of the wings on an RV-8. At the wing tips,
I will have strobes, nav lights, landing lights and antennae. I was
scratching my head about grounding these things. The wing spar is a lovely ground
spot. The outboard-most rib is primed and hence is not a good ground point.
I
was thinking about drilling a 3/16 or so hole in the spar just inboard from
the last rib, inserting a bolt and then using the bolt as a common terminal
for the ground side of the above components. Does that seem reasonable? Is
there a better way to do this?
Regards,
Michael Wynn
RV 8
San Ramon, CA
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: Wingtip Grounding |
--- MIME Errors - No Plain-Text Section Found ---
A message with no text/plain MIME section was received.
The entire body of the message was removed. Please
resend the email using Plain Text formatting.
HOTMAIL is notorious for only including an HTML section
in their client's default configuration. If you're using
HOTMAIL, please see your email application's settings
and switch to a default mail option that uses "Plain Text".
--- MIME Errors No Plain-Text Section Found ---
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Wingtip Grounding |
In a message dated 7/10/06 4:49:04 PM Eastern Daylight Time, MLWynn(at)aol.com
writes:
> Hi folks,
>
> I am getting towards completion of the wings on an RV-8. At the wing
tips,
>
> I will have strobes, nav lights, landing lights and antennae. I was
> scratching my head about grounding these things. The wing spar is a
lovely
> ground
> spot. The outboard-most rib is primed and hence is not a good ground
point.
> I
> was thinking about drilling a 3/16 or so hole in the spar just inboard
from
>
> the last rib, inserting a bolt and then using the bolt as a common
terminal
>
> for the ground side of the above components. Does that seem reasonable?
> Is
> there a better way to do this?
>
> Regards,
>
> Michael Wynn
> RV 8
> San Ramon, CA
============================
Michael:
How are you running all those wires out to the wing tip?
I would suggest a plastic tube about 3/4 to 1" ID
Now that you have the tube and the wires out there just run a #12 wire all
the way out there Do the Double Nut & Bolt through the rib idea you mentioned
BUT, now you can locate the Nut & Bolt at an easy to access point ... Use BRASS
Nut & Bolt with a star washer under the first nut. Then use a washer stack
your ground lugs and another star washer & nut. O! Still want to use the wing
as a ground ... Go right ahead run that wing ground out to the same Nut & Bolt
configuration you just installed.
Years later when yo would want to run another wire for what ever reason ...
EASY no crazy fishing and cursing to do ;-)
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | gary.stiffler(at)kroger.com |
| Subject: | Re: AeroElectric-List Digest: 6 Msgs - 07/09/06 |
>As you have guess and from your description they are FEED-THROUGH
Capacitors.
>Their value is probably in the range of .001 to .01 uF at 20 VDC (WVDC)
or
>more. The voltage should be MORE than the system voltage by 50% and if
you
>find one at 100 VDC (WVDC) you can use that also ... Not critical.
>I'm not understanding your description about the other item. That sounds
>like an Electrolytic capacitor (Polarized ... + & - leads) that is hooked
between
>the 'S' terminal of the ACU and Ground. It's purpose is to filter out
NOISE
>& Spikes. The value of that can be anywhere from say 25,000 uF to
200,000 uF
>and of course the voltage rating should be as described above.
Everyone:
Thanks for the reply, I did not do a good job of describing the second
cylinder that looks like a cap. It has a terminal on each end. One is
connected to the regulator and the other is connected to the alternator.
It had a wire that went into the bakelite on one end that was connected to
the airplane frame ground. I am guessing it is also to eliminate noise.
Does anyone have an idea where I can buy these?
Thanks for all of the help.
Gary
N592GS AA1B
________________________________________________________________________________
| From: | Dennis Haverlah <clouduster(at)austin.rr.com> |
| Subject: | External voltage regulator Connections |
I converted my RX-8 computer controlled alternator (100 amp) to
externally regulated. I purchased an Auto Zone VR 749 external
regulator for a 100 amp alternator. I have a question on how to connect
the regulator to the system.
This is my best guess for the four pins - I, A, S , and F- on the regulator.
1). F on regulator goes to ungrounded brush in alternator.
2) A and S pins on regulator tie together and get fed from 5 amp breaker
and switch.
3). I have no clue about the I pin on the regulator - I'm guessing it
is either an indicator light feed or connects to the ignition switch.
4). The B terminal on the alternator connects to the + at the contactor.
Anyone have better information?
Thanks,
Dennis H.
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: Wingtip Grounding |
That is the way I did mine but I cleaned off the primer and put it in
the end rib. Works fine. Larry in Indiana
----- Original Message -----
From: MLWynn(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Monday, July 10, 2006 3:39 PM
Subject: AeroElectric-List: Wingtip Grounding
Hi folks,
I am getting towards completion of the wings on an RV-8. At the wing
tips, I will have strobes, nav lights, landing lights and antennae. I
was scratching my head about grounding these things. The wing spar is a
lovely ground spot. The outboard-most rib is primed and hence is not a
good ground point. I was thinking about drilling a 3/16 or so hole in
the spar just inboard from the last rib, inserting a bolt and then using
the bolt as a common terminal for the ground side of the above
components. Does that seem reasonable? Is there a better way to do
this?
Regards,
Michael Wynn
RV 8
San Ramon, CA
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: Ammeter Shunt |
I did mine with #2 of your possible choices. Works fine. Shows me what
seems to be the load being consumed and therefore being produced by the Alt.
Larry in Indiana with RV7 flying
----- Original Message -----
>
>
> Hi All,
>
>
> I am about to install the Dynon Ammeter Shunt that comes with the 180
> FlightDeck. It can be installed in 3 locations that can read either:
> 1. Amps
> in and out of battery (-60a to 60a),
> 2. Amps in to the battery from the alternator only
> 3. Amps used by aircraft load only.
>
>
> My question is: where would be the best location to put it? Suggestions
> welcomed.
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: External voltage regulator Connections |
>
>
>I converted my RX-8 computer controlled alternator (100 amp) to
>externally regulated. I purchased an Auto Zone VR 749 external regulator
>for a 100 amp alternator. I have a question on how to connect the
>regulator to the system.
>This is my best guess for the four pins - I, A, S , and F- on the regulator.
>1). F on regulator goes to ungrounded brush in alternator.
>2) A and S pins on regulator tie together and get fed from 5 amp breaker
>and switch.
>3). I have no clue about the I pin on the regulator - I'm guessing it is
>either an indicator light feed or connects to the ignition switch.
Leave "I" unconnected.
The VR-749 is one of several versions of the generic "Ford"
regulator described in Note 21 and Figure Z-23 of
http://aeroelectric.com/articles/Rev11/AppZ_R11H.pdf
>4). The B terminal on the alternator connects to the + at the contactor.
yes.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: AeroElectric-List Digest: 6 Msgs - |
> >As you have guess and from your description they are FEED-THROUGH
> Capacitors.
> >Their value is probably in the range of .001 to .01 uF at 20 VDC (WVDC) or
> >more. The voltage should be MORE than the system voltage by 50% and if you
> >find one at 100 VDC (WVDC) you can use that also ... Not critical.
>
> >I'm not understanding your description about the other item. That sounds
> >like an Electrolytic capacitor (Polarized ... + & - leads) that is
> hooked between
>
> >the 'S' terminal of the ACU and Ground. It's purpose is to filter out
> NOISE
> >& Spikes. The value of that can be anywhere from say 25,000 uF to
> 200,000 uF
> >and of course the voltage rating should be as described above.
>
>Everyone:
>
>Thanks for the reply, I did not do a good job of describing the second
>cylinder that looks like a cap. It has a terminal on each end. One is
>connected to the regulator and the other is connected to the alternator.
>It had a wire that went into the bakelite on one end that was connected to
>the airplane frame ground. I am guessing it is also to eliminate noise.
>Does anyone have an idea where I can buy these?
>
>Thanks for all of the help.
Try running without them and see what happens. Do you
fly with and ADF much? Most of those caps were added
to reduce if not eliminate alternator noise in the ADF.
If you don't fly with ADF, then perhaps you don't even need
them.
If it turns out that you do need them, it's unlikely that
you'll find an exact match in anyone's aviation stock. That
style of filter has become rare. There are some surplus
houses with New Old Stock that might offer a substitute
with satisfactory performance to the task. See:
http://www.surplussales.com/Feedthrus/FTflangeMt.html
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
While working on revision J to Appedix Z, I discovered
that while revision H had been completed a month ago, it never
got posted! So, for the next few days, you can get the latest
update only a month late . . . Rev J is 90% done and will get
posted probably before next weekend.
See:
http://aeroelectric.com/whatsnew.html
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | <rparigor(at)SUFFOLK.LIB.NY.US> |
| Subject: | Small diameter landing light |
I have fooled a bit with different lights to be used as landing lights.
Thus far the bigger the parabolic reflector, the better they seem to work.
Why is it that a huge reflector works better than a smaller one? Is it
that perfect aim of a specific spot on reflector is less critical with a
larger reflector?
Anyone know of a small diameter light (preferless than 2.5") that is
suitable for a landing light and does not make too much heat?
Anyone using a Hella Xenon? Are they as close to a standard cessna landing
light?
Thx.
Ron Parigoris
________________________________________________________________________________
| Subject: | Re: Small diameter landing light |
> Anyone using a Hella Xenon?
We used a XeVison. No probems, except the price.
Some buddies installed Hella lights. Some have experienced noise
problems with the Hella.
http://contrails.free.fr/elec_hid.php
> Are they as close to a standard cessna landing
> light?
>
Not sure I understand your question. The HID lights are bright and their
current draw is low. Some months ago someone raised a visibility issue.
That's old wife's tales.
FWIW,
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: External voltage regulator Connections |
In a message dated 7/10/06 6:27:51 PM Eastern Daylight Time,
clouduster(at)austin.rr.com writes:
> Anyone have better information?
>
> Thanks,
> Dennis H.
==============================
Dennis:
I = INDICATOR
A = ALTERNATOR
S = SWITCH
F = FIELD
BULB/LED GOES TO I AND TO +12 VDC ALT FIELD
Go to the ZIFTRONICS website and download their instruction sheet.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "Jim Ellis" <JEllis9847(at)aol.com> |
| Subject: | Blue Mountain EFIS to TruTrak Connection |
I have been trying to find out if anyone has ever been able to make a working gps
serial connection between a Blue Mountain EFIS and a TruTrak autopilot. I have
made many phone calls and searched all the web sites.
According the BMA the G3 Lite will provide a gps output through one of its two
serial ports in either GPSS (UPS GPS) or standard NMEA-0183 format.
OK.
According to TruTrak their autopilots will accept and read GPSS or NMEA-0183 format
(with the correct baud setting programed into the autopilot).
OK.
Now here's the strange part. None of the tech reps at either company can confirm
that their units will work with the other. Nor do they know if anyone anywhere
has ever made a working connection between the two systems. I find this very
odd that the manufacturers don't know the basic compatibility of the equipment
they sell.
Here is my question for the List. Do you know or have you heard of anyone who has
ever made a working gps serial connection between any Blue Mountain EFIS and
any TruTrak autopilot? If so, I would love to hear from you.
Jim Ellis
RV9-A, Flying (Yippee!)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=46309#46309
________________________________________________________________________________
| From: | Werner Schneider <glastar(at)gmx.net> |
| Subject: | Re: Blue Mountain EFIS to TruTrak Connection |
Jim,
log with hyperterm (or even another better terminal emulation) a
sequence of the BMA (as it is the active component) and send it to
trutrak (passive component). I had to do that 4 years ago, when my
Garmin 196 did not work with my digitrack (old SW version). They were
very helpful and sent me a new digitrack for free.
NMEA-0183 is a set of standard commands, but how the BMA does output
it's path direction is not standardized.
br Werner
Jim Ellis wrote:
>
>I have been trying to find out if anyone has ever been able to make a working
gps serial connection between a Blue Mountain EFIS and a TruTrak autopilot. I
have made many phone calls and searched all the web sites.
>
>According the BMA the G3 Lite will provide a gps output through one of its two
serial ports in either GPSS (UPS GPS) or standard NMEA-0183 format.
>
>OK.
>
>According to TruTrak their autopilots will accept and read GPSS or NMEA-0183 format
(with the correct baud setting programed into the autopilot).
>
>OK.
>
>Now here's the strange part. None of the tech reps at either company can confirm
that their units will work with the other. Nor do they know if anyone anywhere
has ever made a working connection between the two systems. I find this very
odd that the manufacturers don't know the basic compatibility of the equipment
they sell.
>
>Here is my question for the List. Do you know or have you heard of anyone who
has ever made a working gps serial connection between any Blue Mountain EFIS and
any TruTrak autopilot? If so, I would love to hear from you.
>
>Jim Ellis
>RV9-A, Flying (Yippee!)
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=46309#46309
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: External voltage regulator Connections |
>
>
>I converted my RX-8 computer controlled alternator (100 amp) to
>externally regulated. I purchased an Auto Zone VR 749 external regulator
>for a 100 amp alternator. I have a question on how to connect the
>regulator to the system.
>This is my best guess for the four pins - I, A, S , and F- on the regulator.
>1). F on regulator goes to ungrounded brush in alternator.
>2) A and S pins on regulator tie together and get fed from 5 amp breaker
>and switch.
>3). I have no clue about the I pin on the regulator - I'm guessing it is
>either an indicator light feed or connects to the ignition switch.
Leave "I" unconnected.
The VR-749 is one of several versions of the generic "Ford"
regulator described in Note 21 and Figure Z-23 of
http://aeroelectric.com/articles/Rev11/AppZ_R11H.pdf
>4). The B terminal on the alternator connects to the + at the contactor.
yes.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: AeroElectric-List Digest: 6 Msgs - |
> >As you have guess and from your description they are FEED-THROUGH
> Capacitors.
> >Their value is probably in the range of .001 to .01 uF at 20 VDC (WVDC) or
> >more. The voltage should be MORE than the system voltage by 50% and if you
> >find one at 100 VDC (WVDC) you can use that also ... Not critical.
>
> >I'm not understanding your description about the other item. That sounds
> >like an Electrolytic capacitor (Polarized ... + & - leads) that is
> hooked between
>
> >the 'S' terminal of the ACU and Ground. It's purpose is to filter out
> NOISE
> >& Spikes. The value of that can be anywhere from say 25,000 uF to
> 200,000 uF
> >and of course the voltage rating should be as described above.
>
>Everyone:
>
>Thanks for the reply, I did not do a good job of describing the second
>cylinder that looks like a cap. It has a terminal on each end. One is
>connected to the regulator and the other is connected to the alternator.
>It had a wire that went into the bakelite on one end that was connected to
>the airplane frame ground. I am guessing it is also to eliminate noise.
>Does anyone have an idea where I can buy these?
>
>Thanks for all of the help.
Try running without them and see what happens. Do you
fly with and ADF much? Most of those caps were added
to reduce if not eliminate alternator noise in the ADF.
If you don't fly with ADF, then perhaps you don't even need
them.
If it turns out that you do need them, it's unlikely that
you'll find an exact match in anyone's aviation stock. That
style of filter has become rare. There are some surplus
houses with New Old Stock that might offer a substitute
with satisfactory performance to the task. See:
http://www.surplussales.com/Feedthrus/FTflangeMt.html
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
While working on revision J to Appedix Z, I discovered
that while revision H had been completed a month ago, it never
got posted! So, for the next few days, you can get the latest
update only a month late . . . Rev J is 90% done and will get
posted probably before next weekend.
See:
http://aeroelectric.com/whatsnew.html
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Ernest Christley <echristley(at)nc.rr.com> |
| Subject: | Converting to external regulators |
AeroElectric-List Digest Server wrote:
>From: Dennis Haverlah <clouduster(at)austin.rr.com>
>Subject: AeroElectric-List: External voltage regulator Connections
>
>
>I converted my RX-8 computer controlled alternator (100 amp) to
>externally regulated.
>
>
I have been reading these IVR vs EVR arguments for so long I must be
getting senile. I'm sure this idea has been covered, but for the life
of me I can't remember when and I can't find a reference to it in my
archives.
George makes a good point that the IVR was designed to work in a
specific way by smart people with lots of money to spend on the
problem; a way that does not include people turning it off and on. Bob
makes an excellent point that the pilot has always had complete control
over the power producing entity, and there is little reason to give that
up now. The choice seems to be that you must choose one or the other.
But wouldn't it be a simple modification to break the wires going to the
field brushes and bring them out to a double throw panel switch? The
IVR functionality is maintained, load dump of the field coil has no
where to go (double throw to break both sides of the path
simultaneously), and the pilot has complete control.
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
________________________________________________________________________________
| From: | fiveonepw(at)aol.com |
| Subject: | Re: Small diameter landing light |
These have worked well for me with 100w halogen bulbs:
http://websites.expercraft.com/n51pw/index.php?q=log_entry&log_id=5257
Scroll through the pages using the >>Next entry>> link at the top of each page
& click on fotos for bigger view.
Mark Phillips
-----Original Message-----
Anyone know of a small diameter light (preferless than 2.5") that is
suitable for a landing light and does not make too much heat?
________________________________________________________________________
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
7/11/2006
Responding to an AeroElectric-List message previously posted by: "Mark
Chamberlain"
Hello Mark, I would appreciate some help from you and others to better
understand this subject.
You wrote: "1. Amps in and out of battery (-60a to 60a)"
I understand the above statement and how to wire in order to measure all of
those amps.
If one puts the shunt in the wire going from the battery plus terminal to
the input to the battery contactor you will be able (with the proper kind of
guage) to measure all of the amps going into and out of the battery itself.
This presumes that: A) The alternator B lead is connected to the battery
through the contactor output terminal, and B) That you are operating such
that you don't have some sort of endurance / essential bus or hot battery
bus, also connected directly to the battery plus terminal, that is feeding
amps to some portion of the aircraft's system not through the wire going to
the battery contactor.
You wrote: "3. Amps used by aircraft load only."
I understand how this can be measured by placing the shunt in a wire going
from the battery contactor output terminal to the aircraft's main power
distribution bus. Amps from the alternator, which has its B lead connected
to the battery contactor output terminal, and, if need be, amps from the
battery, would flow through this shunt to carry the aircraft system's load.
Again with no "back door" flows not going through this wire.
You wrote: "2. Amps in to the battery from the alternator only."
I am not sure what you mean by this statement. Do you mean "Only the amps
that are flowing from the alternator into the battery and none of the amps
that are flowing from the alternator into the aircraft systems?"
Assuming that we are talking about a simple system with only one battery and
one alternator there are only two sources of amps possible -- the battery
and the alternator. Recall that the amperage flowing into the battery from
the alternator is one of the two things being measured as wired in scenario
1 above.
Can you please explain what you mean by statement 2 and how one would wire
to accomplish it?
I know that Bob Nuckolls has a very low opininion of some electrical
instrumentation in the aircraft's instrument panel and the pilot's
expectations of beneficially using that instrumentation in flight. I am
basically in agreement with him and am not trying to wire an airplane. I
just want to better understand the concepts involved. Thanks.
OC
Hi All,
I am about to install the Dynon Ammeter Shunt that comes with the 180
FlightDeck. It can be installed in 3 locations that can read either:
1. Amps
in and out of battery (-60a to 60a),
2. Amps in to the battery from the alternator only
3. Amps used by aircraft load only.
My question is: where would be the best location to put it? Suggestions
welcomed.
Thanks for your help,
Mark
________________________________________________________________________________
| From: | "John McMahon" <blackoaks(at)gmail.com> |
| Subject: | Grounding lugs and transponder radiation |
Bob,
In your writings you suggest a grounding or through firewall brass bolt of
5/16" diameter.
In your article on local grounding, the notation on the photo suggests a
1/4" or 5/16" bolt. Lancair used 1/4" studs through the firewall on my ES.
Are these sufficient or should I change them to 5/16"? I'm using #2 welding
cable for my big wires.
Second question regards the transmission of the transponder signal. Does
the signal rediate from the shaft and the ball or only the ball at the tip?
I have a suggestion for future revisions. The military flight manuals mark
the revised material in each change with a dark bar in the margin. I don't
know it would be possible for you do do something similar with your word
processor to make finding the changes in your text revisions.
Thanks for all your information and insights, also your PATIENCE. We got a
lot out of and very much enjoyed the Prescott seminar.
>
>
John McMahon
Lancair Super ES
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Grounding lugs and transponder radiation |
On Jul 11, 2006, at 7:36 PM, John McMahon wrote:
> Second question regards the transmission of the transponder
> signal. Does the signal rediate from the shaft and the ball or
> only the ball at the tip?
The signal is radiated only from the shaft of the antenna. The ball
is just there mainly to keep people from getting hurt when they bump
into it.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 11, 2006, at 7:40 PM,
wrote:
> You wrote: "2. Amps in to the battery from the alternator only."
>
> I am not sure what you mean by this statement. Do you mean "Only
> the amps that are flowing from the alternator into the battery and
> none of the amps that are flowing from the alternator into the
> aircraft systems?"
>
> Assuming that we are talking about a simple system with only one
> battery and one alternator there are only two sources of amps
> possible -- the battery and the alternator. Recall that the
> amperage flowing into the battery from the alternator is one of the
> two things being measured as wired in scenario 1 above.
>
> Can you please explain what you mean by statement 2 and how one
> would wire to accomplish it?
I think that he meant the output of the alternator so it was a
misprint. Still, if you think about it, if you have a shunt in the
lead to the battery, when the alternator is working that shunt will
measure only current from the alternator to the battery. If the
alternator is off-line that same shunt will show all the loads as
they are now being powered by the battery, not the alternator.
> I know that Bob Nuckolls has a very low opininion of some
> electrical instrumentation in the aircraft's instrument panel and
> the pilot's expectations of beneficially using that instrumentation
> in flight. I am basically in agreement with him and am not trying
> to wire an airplane. I just want to better understand the concepts
> involved. Thanks.
I am a fan of the alternator load meter. It is amazing how, during
the day you look down at that ammeter and wonder why there are about
5A more load than usual. That is when you realize that you
inadvertently left the position lights on from your last night
flight. (And if any of you tell me you haven't done this I will say
that you are not telling the whole truth.)
For what it's worth, I actually see a use for the battery ammeter. I
like to see how long it takes the battery to stop accepting current
from the alternator. This tells me when the battery has replaced its
lost charge. The time also gives me an inkling of battery capacity.
When the battery has lost most of its capacity it will "recharge"
much more quickly than usual. It is another one of those things that
you just get a feel for, kind of like the way the engine sounds and
where the controls are under normal circumstances. Oil pressure is
not a particularly useful gauge until it says something new and
different too. It is just another one of those ways that you "feel"
the way the airplane and its systems are working.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Grounding lugs and transponder radiation |
In a message dated 7/11/06 10:03:23 PM Eastern Daylight Time,
brian-yak(at)lloyd.com writes:
> > Second question regards the transmission of the transponder
> > signal. Does the signal rediate from the shaft and the ball or
> > only the ball at the tip?
>
> The signal is radiated only from the shaft of the antenna. The ball
> is just there mainly to keep people from getting hurt when they bump
> into it.
==========================================================
Brian - Group:
A bit of clarification:
If it is metal and it is attached to the antenna (straight portion of the
shaft) it is radiating. There are two reasons for the BALL:
1 - To prevent Corona Discharge - Which is a static discharge that occurs at
antenna ends when there is a SHARP mechanical end to an antenna.
2 - As Brian described - It helps prevent injuries when working around the
antenna.
The other part of the antenna which many tend to forget is the Metal mounting
surface - It functions as a Reflector aka Ground Plane (Plane as in an axis
... X, Y or Z. In this case an X axis.) Without it the radiation pattern
would be very poor and your transmit & receive signal would be very weak. You
would also have a high SWR (Standing Wave Ratio) and that would reduce your
signal and shorten the life of the Xponder output circuit.
Now, your next question should be: What about planes that are not made out of
metal, such as the Long EZ type? Well, they install a [or should install]
small metal reflective surface. This can be thin sheet metal or even peel and
stick copper tape. It can be mounted directly on the outside of the plane,
imbedded into the composite lay-up or on the inside. Only thing that matters is
that it is mechanical and electrically connected to the antenna.
When doing the math for the construction of the antenna [because all
electrical wavelengths are converted to a mechanical wave length or part there
of] the
Ball must be taken into account for the overall length. This is especially
true at the higher frequencies VHF, UHF and Microwave. Transponders are
Microwave.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | "T. Graziano" <tonyplane(at)bellsouth.net> |
| Subject: | Re Blue Mountain EFIS to TruTrak Connection |
I have a BM EFIS Lite G-3 in my Zodiac 601XL and a Trio Avionics EZ Pilot II
which accepts NMEA 0183 data stream. Below is an excerpt from my POH on
how it works on mine, and also with the Garmin 195 and 296. Note when using
the BM EFIS for AP data stream to my EZ Pilot II , I must have the EFIS AP
setting on COURSE BUG.
Hope this may help.
Tony Graziano
Zodiac 601XL, N493TG 118 hrs
"GENERAL OPERATING INSTURCTIONS ON THE USE OF THE AUTOPILOT:
With The Auto Pilot turned ON
A. For use with the EFIS providing navigation (the
switch below the Autopilot is in the EFIS position):
1. Push the AP Button of the EFIS.
2. Select Source and scroll to and select COURSE BUG
3. Push the SET Button and select the destination and/or the Virtual VOR you
wish to go to,
4. Push the DSP Button and select the HSI.
5. Place the Course Bug on the of the GPS Destination or Virtual VOR Pointer
using the outer knob
6. Push ON the Servo Button of the Autopilot and the aircraft will turn to
and TRACK to the Course Bug Heading. The Autopilot should be in the Track
mode.
NOTE: The EFIS Course Bug is a heading Bug corrected for wind. In other
words, it determines the aircraft's track across the ground regardless of
the wind conditions. Be aware that in case of a crosswind, the nose of the
aircraft will be pointed into the wind and not to the selected course.
Rotate the outer knob on the EFIS to change the course Bug. While flying
the Course Bug, the Autopilot will list "BUG" vice a destination.
A. For use with the Garmin GPS 295 or 296 (the switch below
the Autopilot must be in the Garmin position and the switch below the EFIS
switched to either the GPS 296 or to the 295, whichever will be used to
provide navigation data.)
1. With a GOTO destination, via any waypoints as selected
on the Garmin unit, simply push ON the Autopilot Servo Button and the
Autopilot will turn to and track the airplane to the destination.
Consult the EZ Pilot Operation and Installation Manual for detailed
information on us
> From: "Jim Ellis" <JEllis9847(at)aol.com>
> Subject: AeroElectric-List: Blue Mountain EFIS to TruTrak Connection
>
>
> I have been trying to find out if anyone has ever been able to make a
working gps
> serial connection between a Blue Mountain EFIS and a TruTrak autopilot. I
have
> made many phone calls and searched all the web sites.
>
> According the BMA the G3 Lite will provide a gps output through one of its
two
> serial ports in either GPSS (UPS GPS) or standard NMEA-0183 format.
>
> OK.
>
> According to TruTrak their autopilots will accept and read GPSS or
NMEA-0183 format
> (with the correct baud setting programed into the autopilot).
>
> OK.
>
> Now here's the strange part. None of the tech reps at either company can
confirm
> that their units will work with the other. Nor do they know if anyone
anywhere
> has ever made a working connection between the two systems. I find this
very
> odd that the manufacturers don't know the basic compatibility of the
equipment
> they sell.
>
> Here is my question for the List. Do you know or have you heard of anyone
who has
> ever made a working gps serial connection between any Blue Mountain EFIS
and
> any TruTrak autopilot? If so, I would love to hear from you.
>
> Jim Ellis
> RV9-A, Flying (Yippee!)
________________________________________________________________________________
| From: | Dennis Haverlah <clouduster(at)austin.rr.com> |
| Subject: | Re: External voltage regulator Connections |
Thanks for the advice on connecting the external regulator. I wound up
using Bob's Z-23 regulator connection diagram. The alternator is
working great!.
Thanks Again!
Dennis H.
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Converting to external regulators |
>
>George makes a good point that the IVR was designed to work in a specific
>way by smart people with lots of money to spend on the problem; a way
>that does not include people turning it off and on. Bob makes an
>excellent point that the pilot has always had complete control over the
>power producing entity, and there is little reason to give that up
>now. The choice seems to be that you must choose one or the other.
>But wouldn't it be a simple modification to break the wires going to the
>field brushes and bring them out to a double throw panel switch?
You betcha! But that puts the alternator at-risk for
having been 'modified'. Once you open it up, the service
life may be affected by the modifier's lack of experience
and/or understanding of the recipe for success.
If one is willing and able to open any alternator for
the purpose of modifying it, then one might as well
bring the field leads out for excitation by an externally
mounted regulator which offers an opportunity for . . .
Adjustability
Remote sensing of regulation voltage
Graceful, low energy OV management
Temperature compensation
Easy diagnosis of failures and opportunity
to replace a regulator without pulling the
alternator.
and finally . . . absolute, any time, any conditions
control.
For all it's virtues the as-supplied, internal
regulator offers no better performance than an
externally mounted regulator and forces the builder
to accept new design goals. If those conditions are
acceptable . . . great. If one is desirous of
achieving any one or all of the above design goals,
then some modifications are necessary. Once you
open that puppy up, you might as well make it conform
to the classic 'aircraft' configuration.
Folks who design cars had NONE of the aforementioned
design goals. The present state of the art for automotive
alternators has followed a logical and economically sound
evolution - for cars. Much of what's been developed and proven
in automobiles is slowly and painfully finding its way
onto airplanes. However, just because a particular philosophy has
become a highly developed, widely accepted practice in
cars does not automatically force the airplane builder
to give up desirable design goals.
> The IVR functionality is maintained, load dump of the field coil has no
> where to go (double throw to break both sides of the path
> simultaneously), and the pilot has complete control.
You only need to open one side. A single pole switch
would suffice nicely.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Converting to external regulators |
On Jul 12, 2006, at 11:27 AM, Robert L. Nuckolls, III wrote:
> For all it's virtues the as-supplied, internal
> regulator offers no better performance than an
> externally mounted regulator and forces the builder
> to accept new design goals. If those conditions are
> acceptable . . . great. If one is desirous of
> achieving any one or all of the above design goals,
> then some modifications are necessary. Once you
> open that puppy up, you might as well make it conform
> to the classic 'aircraft' configuration.
An analogy: would you buy an engine and prop combination that you
could not change on your aircraft? They came as a unit and no matter
what you did, you could not change the prop to match the operating
parameters of your aircraft?
I am very much with Bob on this. I want the ability to have complete
and total control over my charging system. I cannot do that with an
IR alternator. There is no way to force the IR alternator to turn off
without modification. (Using the 'I' lead to turn the alternator on
or off is dependent on the internal regulator continuing to behave
normally and when it is behaving abnormally is precisely the time
when I need it to behave normally and turn off when I turn off the
'I' lead.) It is just easier to use an ER alternator and wire up an
external regulator.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Ammeter Shunt |
Brian,
Am I understanding correctly, that with a shunt between the alternator
and battery, the ammeter will display amp load on the battery when the
alternator is off-line?
John
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Re: Ammeter Shunt |
7/12/2006
Hello Mark, Thanks for the quick response.
You wrote: "In the diagram I have from Dynon it says that if you put the
shunt
between the alternator and the battery (somewhere in the main power lead
from the alternator) it will measure only amps coming from the
alternator."
Yes, I agree. And those amps will be flowing into both the aircraft systems
and into recharging the battery if the voltage regulator is holding the
alternator output voltage at a battery charging level.
There is no way that I know of to wire the aircraft using only one shunt or
Hall effect device in a way that will display the alternator load share
between aircraft systems and battery charging.
So your three choices are:
A) As You wrote: "1. Amps in and out of battery (-60a to 60a)"
B) As You wrote: "3. Amps used by aircraft load only."
C) Or, Amps flowing out of the alternator to both charge the battery and
feed the aircraft systems in some unknown proportion. (Per the diagram from
Dynon)
So where are you going to put the shunt?
OC
----- Original Message -----
Sent: Wednesday, July 12, 2006 10:39 AM
Hi,
In the diagram I have from Dynon it says that if you put the shunt
between the alternator and the battery (somewhere in the main power lead
from the alternator) it will measure only amps coming from the
alternator.
Hope this helps,
Mark
-----Original Message-----
Sent: Tuesday, July 11, 2006 4:41 PM
7/11/2006
Responding to an AeroElectric-List message previously posted by: "Mark
Chamberlain"
Hello Mark, I would appreciate some help from you and others to better
understand this subject.
You wrote: "1. Amps in and out of battery (-60a to 60a)"
I understand the above statement and how to wire in order to measure all
of
those amps.
If one puts the shunt in the wire going from the battery plus terminal
to
the input to the battery contactor you will be able (with the proper
kind of
guage) to measure all of the amps going into and out of the battery
itself.
This presumes that: A) The alternator B lead is connected to the battery
through the contactor output terminal, and B) That you are operating
such
that you don't have some sort of endurance / essential bus or hot
battery
bus, also connected directly to the battery plus terminal, that is
feeding
amps to some portion of the aircraft's system not through the wire going
to
the battery contactor.
You wrote: "3. Amps used by aircraft load only."
I understand how this can be measured by placing the shunt in a wire
going
from the battery contactor output terminal to the aircraft's main power
distribution bus. Amps from the alternator, which has its B lead
connected
to the battery contactor output terminal, and, if need be, amps from the
battery, would flow through this shunt to carry the aircraft system's
load.
Again with no "back door" flows not going through this wire.
You wrote: "2. Amps in to the battery from the alternator only."
I am not sure what you mean by this statement. Do you mean "Only the
amps
that are flowing from the alternator into the battery and none of the
amps
that are flowing from the alternator into the aircraft systems?"
Assuming that we are talking about a simple system with only one battery
and
one alternator there are only two sources of amps possible -- the
battery
and the alternator. Recall that the amperage flowing into the battery
from
the alternator is one of the two things being measured as wired in
scenario
1 above.
Can you please explain what you mean by statement 2 and how one would
wire
to accomplish it?
I know that Bob Nuckolls has a very low opinion of some electrical
instrumentation in the aircraft's instrument panel and the pilot's
expectations of beneficially using that instrumentation in flight. I am
basically in agreement with him and am not trying to wire an airplane. I
just want to better understand the concepts involved. Thanks.
OC
Hi All,
I am about to install the Dynon Ammeter Shunt that comes with the 180
FlightDeck. It can be installed in 3 locations that can read either:
1. Amps
in and out of battery (-60a to 60a),
2. Amps in to the battery from the alternator only
3. Amps used by aircraft load only.
My question is: where would be the best location to put it? Suggestions
welcomed.
Thanks for your help,
Mark
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Transponder and radio to sell |
Hi guys
I am a Portuguese homebuilder who is building an RV-9A.
Some time ago I bought a NARCO AT 155 transponder, but didn't install yet.
Since in Europe it's going to be mandatory next year to have a mode S
transponder, I'll have to buy something like a Garmin 330. Therefore, I am
willing to sell the Narco AT 155. Although it is brand new, never installed
or used, I am accepting less than I payed for it ($1.149).
I also bought an ICOM A-200 TSO'd comm radio, which I'm also willing to
sell, because I'm thinking in buying a GARMIN SL-40 (or an SL-30 if Santa is
generous with me). The ICOM radio is also still in the box, and I also
accept less than it's new price ($849).
Those interested please contact me offlist.
I will go to Oshkosh this year, I can deliver both there.
Carlos
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 12, 2006, at 1:42 PM, John Burnaby wrote:
> Brian,
>
> Am I understanding correctly, that with a shunt between the
> alternator and battery, the ammeter will display amp load on the
> battery when the alternator is off-line?
Bob's book explains this better than I can but I will take a stab at it.
There is a point in the electrical system where the alternator, the
battery, and the distribution bus all connect together. This is
usually at the junction of the battery master contactor and the
starting contactor. (It may also be at your positive distribution
point for your bus.) You can put an ammeter shunt or a hall-effect
current sensor in any one of the three wires coming to that point.
1. If you put the shunt in the wire (B-lead) from the alternator, the
ammeter will read the current being drawn from the alternator. This
is usually called a "load meter".
2. If you put the shunt in the wire going to the distribution bus,
the ammeter will read the loads on the electrical system.
3. If you put the shunt in the lead going to the battery, the ammeter
will read the current going from the alternator to the battery when
the alternator is on-line and the battery is charging (positive amps)
or it will read the bus loads if the alternator is off-line (negative
amps). This is the typical center-zero battery ammeter you find in
most Cessna aircraft.
(Piper switched from #3 to #1 somewhere along the line. I think
Cessna still uses #3. The only place I have seen #2 is on larger
aircraft with multiple charging and load buses.)
Bob doesn't like the center-zero battery ammeter (#3) and I have to
admit, it is not particularly useful most of the time. When the
battery is charging it shows charging current but that drops to zero
so you really can't tell anything. OTOH, if the alternator goes off-
line, you can see the loads and estimate the remaining battery "run-
time" by seeing how many amps you are pulling out of it. If you have
a 25AH battery and you are drawing 5A, you can expect the battery to
provide power for about 5 hours before it goes dead.
(And for those of you who are about to correct me to tell me that
when you draw more amps from a battery its amp-hour rating goes down,
you are correct but I am trying to make a general point here with
relatively simple arithmetic and without a discussion of Peukert's
exponent.)
The bottom line is that you cannot tell everything about the current
flows in your electrical system without at least TWO ammeters.
But Bob is certainly right about needing a voltmeter. It is more
useful than an ammeter under just about every condition.
Brian Lloyd 361 Catterline Way
brianl at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
"Five percent of the people think.
Ten percent of the people think they think.
Eighty-five percent of the people would rather die than think."
---Thomas A. Edison
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "europa flugzeug fabrik" <n3eu(at)comcast.net> |
| Subject: | Re: Grounding lugs and transponder radiation |
brian wrote:
> The signal is radiated only from the shaft of the antenna.
A couple theoretical texts I have suggest it radiates only from the base of the
antenna. Has to do with 90-deg phase lag, current and voltage, I think. The
vertical element is there merely to resonate.
Dunno also, but the ball has been alleged to be either a capacity hat, or to have
proverse effect on radiating pattern. One such allegation came from a retired,
aircraft antenna engineer I know. But he thinks my questions are often
inane! [Wink]
Fred F.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=46771#46771
________________________________________________________________________________
| From: | "Ed Holyoke" <bicyclop(at)pacbell.net> |
Yeah---but, if the alternator is offline, won't you shut off the
contactor to save the 1 amp (and shed loads) and isn't the shunt now
offline?
Pax,
Ed Holyoke
-----Original Message-----
> 3. If you put the shunt in the lead going to the battery, the ammeter
will read the current going from the alternator to the battery when
the alternator is on-line and the battery is charging (positive amps)
or it will read the bus loads if the alternator is off-line (negative
amps). This is the typical center-zero battery ammeter you find in
most Cessna aircraft.
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Grounding lugs and transponder radiation |
On Jul 12, 2006, at 7:31 PM, europa flugzeug fabrik wrote:
>
>
>
> brian wrote:
>> The signal is radiated only from the shaft of the antenna.
>
> A couple theoretical texts I have suggest it radiates only from the
> base of the antenna.
The entire antenna radiates but most of the radiation comes from the
portion of the conductor with the greatest current. Since the current
node occurs at the feed point of a 1/4 wave antenna, you are correct
in that the portion of the conductor nearer the base radiates more of
the signal. Regardless, the entire radiator radiates to one extent or
another.
If you want you can make a 1/2 wave radiator and feed it at the
voltage node (the end). Now you don't need much of a counterpoise
(ground) at all because the current is very low at the feedpoint. In
that case radiation is primarily from the current node which is now
at the center of the radiator. This is commonly used where a ground
is not available, such as on plastic cars and boats.
> Dunno also, but the ball has been alleged to be either a capacity
> hat, or to have proverse effect on radiating pattern.
It doesn't really have enough area to be a capacity hat but even so,
all that would do is to allow you to reduce the length of the
radiator and still be in resonance. It could be a way to reduce
corona discharge but the power levels used by transponders is low
enough that it really isn't an issue.
I don't have any of my antenna books with me but, as I recall, the
effective impedance of an end-fed 1/2 wave antenna is about 2000
ohms. Since the voltage node of a 1/4 wave antenna (the free end)
should be about the same, I should be able to calculate the voltage
at the end of 1/4 wave antenna.
Assuming that the 1/4 wave antenna is resonant, the impedance should
be 100% resistive so I can use the standard ohms law stuff to
calculate voltage. For resistive loads it is:
P = V^2/R
(power equals voltage squared divide by resistance)
If your transponder puts out a peak power of 200W we have:
200 = V^2 / 2000
If we do the algebra we get:
V = sqrt (200 * 2000) or 632V
I don't think we are going to get a corona discharge from 632V. It
could produce a pretty good RF burn if you touch it tho'.
(BTW, I could be wrong about the impedance at the voltage node and
that would skew things a bit but I am pretty sure I am in the ballpark.)
Therefore I hold that the ball is there to keep you from poking holes
in yourself should you rise up rapidly whilst cleaning exhaust stains
off the belly of your airplane prior to judging at OSH.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 12, 2006, at 8:49 PM, Ed Holyoke wrote:
>
>
> Yeah---but, if the alternator is offline, won't you shut off the
> contactor to save the 1 amp (and shed loads) and isn't the shunt now
> offline?
It depends on how you wire your electrical system. If I have 5 hours
of battery life including the battery contactor and I have 4 hours of
fuel on board ...
But if you have a separate battery feed to your endurance bus you
might want a second shunt to read loads on the endurance bus. You may
want then information to load shed to increase battery endurance.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 12, 2006, at 9:22 PM, Brian Lloyd wrote:
> It depends on how you wire your electrical system. If I have 5
> hours of battery life including the battery contactor and I have 4
> hours of fuel on board ...
>
> But if you have a separate battery feed to your endurance bus you
> might want a second shunt to read loads on the endurance bus. You
> may want then information to load shed to increase battery endurance.
A further comment: the original question was on the ammeter shunt (or
hall-effect sensor). There are many ways to craft the topology of
your electrical system as Bob has shown in his book and discussions
herein. But there are only a few places you can put an ammeter and
get meaningful information.
1. You can put one in series with any source of power (alternator,
generator, dynamo) and find out how much current it is delivering.
2. You can put one in series with a battery and see either its
charging current or loads when the charging current is insufficient
to carry all the loads (as in when the alternator is turning too
slowly or is off-line).
3. You can put one in series with a load or loads and see how much
current that device or devices demand from the system.
If you change the path so that the current no longer travels through
the shunt then you won't get any reading. Heck, you can put the shunt
permanently in the path to the battery so it always shows battery
current, even starting current. Then you can always see what is going
into and coming out of your battery. Just make sure your shunt is
beefy enough to handle the starting currents.
The above is true regardless of the number of alternators or
batteries in your system.
Bob makes a point that all this discussion is so you can craft your
electrical system to do what YOU want it to do. You may have
different reasons to measure current than Bob or I do. Bob doesn't
like the center-zero battery ammeter and I understand that. I have
developed new respect for this instrument in applications where one
will be running from battery power.
Here is another way of looking at it. If you have two sources of
power (alternators/dynamos) you are never going to be running your
loads off your battery. It is only needed to start the airplane. The
center-zero battery ammeter is almost useless in that system. OTOH if
you have a single alternator system and will depend on the battery to
get you to your destination should the alternator fail, you might
want to know what the loads are so you can estimate remaining battery
capacity. Now the center-zero ammeter is useful.
I have a boat with a 1000AH battery bank. That battery bank provides
all of the boat's power when I am at sea. I have to periodically
recharge it. I want to know how much capacity I have consumed so I
know how much is left and I want to know when it is fully charged. In
this application the battery ammeter/shunt is critical. No other tool
will suffice.
So it all depends on your application.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Bob Lee" <bob(at)flyboybob.com> |
Brian Lloyd Wrote:
<<
But if you have a separate battery feed to your endurance bus you
might want a second shunt to read loads on the endurance bus.
>>
If you use a hall-effect sensor rather than a shunt you could run the
endurance bus feed as well as the battery bus feed through the sensor and
that way the ammeter would report total of battery bus and endurance bus
(depending on which one was energized).
Regards,
Bob Lee
N52BL KR2
Suwanee, GA
91% done only 65% to go!
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>Brian Lloyd Wrote:
><<
>But if you have a separate battery feed to your endurance bus you
>might want a second shunt to read loads on the endurance bus.
> >>
>
>If you use a hall-effect sensor rather than a shunt you could run the
>endurance bus feed as well as the battery bus feed through the sensor and
>that way the ammeter would report total of battery bus and endurance bus
>(depending on which one was energized).
Battery busses and endurance busses (if wired per the z-figures)
are always energized in one way or another. There is one pretty
useful dual-feedline use for a hall-sensor. You can run both
alternator leads thorough it and have it read total load for
both machines operating either independently or together.
The questions to be asked and answered are: If I want to install
any form of current monitoring device on the panel, what is
the design goal for utility? One can select from a variety
of locations all of which will present different information
and different dynamics. Keep in mind that the first task to
be completed for any architecture is a load analysis based on
distribution of equipment across the various busses. The load
analysis tells you that for any and all operating conditions,
no current limited is exceeded -OR- during "plan-b" ops,
certain loads must be turned off to meet endurance goals
or to observe certain PRE-DETERMINED load limits.
Bottom line is that EVERY current draw for EVERY mode of
operation should be known to you before your first flight.
An ammeter display of any variety is but one snapshot into
system performance that might have some usefulness during
a future troubleshooting activity as a technician. But
if one has done their homework before first flight,
ammeters are 95% useless to operating the airplane as
pilot.
I'm not trying discourage all the discussion about where
shunts/hall-sensors can be placed and what they will show.
But for the 1300 or so who are not participating in the
conversation, know that whatever deductions are
accomplished, don't think that ANY ammeter has much
utility as an aid to flight operations no matter where
it's installed.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | =?iso-8859-1?Q?Mich=E8le_MS?= <michele.delsol(at)microsigma.fr> |
| Subject: | External Power and electrical system isolation |
Listers,
I have been planning on adding external power to my system (one alternator,
one battery, PMag IO360). My original design was pretty simple, hook it
straight onto the battery such as one does when jump starting a car. Then I
added a relay so that the external power terminals would not be hot when not
connected to external power. Then some knowledgeable fellow builders told me
that I should only use external power for starting the engine nothing
else. Then some other knowledgeable builders told me that I could install a
cigar lighter jack in parallel as an external power connector for recharging
the battery. Then there was the issue as to external power not being clean
DC current and consequently liable to play havoc with some of my sensitive
equipment. Based on this I proceeded to design a circuit which would
automatically disconnect all electricals except for the starter solenoid,
current to the PMags and current to my fuel pump. Whereupon another
knowledgeable person suggested that I should remember the KISS principle I
may be over designing my system.
What do you guys suggest isolate my electrical system when external power
is hot or just hook it up onto the battery via a relay?
Thanks,
Michele Delsol
RV8 Fuselage
________________________________________________________________________________
| Subject: | Phone jack conventions |
U2F5IC0gSSd2ZSBub3RpY2VkIHRoYXQgUFMgRW5nci4gaGFzIHN3YXBwZWQgdGhlIEwvUiBvbiB0
aGUgdGlwL21pZGRsZSBzZWN0aW9uIG9mIHRoZSBqYWNrcyAtIG9uIHRoZSBQTUE4MDAwQiB2cyB0
aGUgUE1BNzAwMEIuICBUaGV5IGFsc28gY2hhbmdlZCB0aGUgZW50ZXJ0YWlubWVudCBpbnB1dHMg
YXMgd2VsbCAtIHNvIEwvUiBzdGVyZW8gaW1hZ2luZyBzaG91bGQganVzdCAncGFzcyB0aHJ1Jy4N
CiANCkkgYW0gdHJ5aW5nIHRvIGRvY3VtZW50IHRoZSBhY3R1YWwgTC9SIC0gY2FuIHNvbWVvbmUg
aGVscCBjbGFyaWZ5IHdoYXQgcG9ydGlvbiBvZiB0aGUgamFjayByZWFsbHkgaXMgdGhlIEwgYW5k
IHdoYXQgaXMgdGhlIFI/DQogDQpUaGFua3MsDQogDQpKb2huDQo
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: External Power and electrical system isolation |
Afternoon, Michele
>>hook it straight onto the battery such as one does when jump starting
a car<<
I'm not familiar with an RV8, as I have a Long EZ (hangar neighbor has
an RV6, though), but my philosophy is as you said...the KISS principal.
Fewer plugs, relays, switches, cables and wires means less weight in the
plane and fewer things to fail and possibly cause problems with other
devices even when the ground power is NOT connected.
>>so that the external power terminals would not be hot when not
connected to external power.<<
You lost me here. The external terminals? Can't you just clip a trickle
charger directly onto the battery? Leave the master switch off when
charging, and you should be fine. Remove the charger when flying and you
have a nice, light, safe craft!
That way, you'll always have a full battery, and should never have
problems having enough juice to start the plane.
Harley Dixon
Long EZ N28EZ
Canandaigua, NY
Michle MS wrote:
>
> Listers,
>
> I have been planning on adding external power to my system (one alternator,
> one battery, PMag IO360). My original design was pretty simple, hook it
> straight onto the battery such as one does when jump starting a car. Then I
> added a relay so that the external power terminals would not be hot when not
> connected to external power. Then some knowledgeable fellow builders told me
> that I should only use external power for starting the engine -- nothing
> else. Then some other knowledgeable builders told me that I could install a
> cigar lighter jack in parallel as an external power connector for recharging
> the battery. Then there was the issue as to external power not being clean
> DC current and consequently liable to play havoc with some of my sensitive
> equipment. Based on this I proceeded to design a circuit which would
> automatically disconnect all electricals except for the starter solenoid,
> current to the PMags and current to my fuel pump. Whereupon another
> knowledgeable person suggested that I should remember the KISS principle -- I
> may be over designing my system.
>
> What do you guys suggest -- isolate my electrical system when external power
> is hot or just hook it up onto the battery via a relay?
>
> Thanks,
> Michele Delsol
> RV8 Fuselage
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "europa flugzeug fabrik" <n3eu(at)comcast.net> |
| Subject: | Re: Grounding lugs and transponder radiation |
brian wrote:
> ...If your transponder puts out a peak power of 200W we have:
>
> 200 = V^2 / 2000
>
> If we do the algebra we get:
>
> V = sqrt (200 * 2000) or 632V....
>
>
That could be for what I know, but I thought we worked on 50 ohms by fiat. I have
a musty, ancient xponder service manual I eBayd cheap for maybe giggles. To
measure power, they had you kludge a commercial voltage detector together with
a special diode, IN23B. Then you observed reply pulse trains on any whatever
scope and counted P-P volts by graticule divisions. Volts squared, divided by
50 (into a dummy 50-ohm load) and thems peak watts. So only 100V P-P would
work out to 200W.
Thats the purists approach, and funny that around 1990, I had my xponder check
done by a crotchety old-timer. Hed ramp check also Mode C by observing similarly
kludged, detected xponder output on what looked like his Dads old scope --
on wheels. For his selected altitude test points per Part 43, he had sketched
the bit pattern on little index cards. Head cocked skyward to use his bifocals,
holding said card up to the scope with round display. Pump vacuum at the
plane, then run to the scope to check. He had to work fast, as permissible leak-down
in the static sys at higher alts can cause up to multiple bits to flip
Grey-code style (he seemed to rely on an observed time lag). Who needs very
expensive equipment, when all you need are FAA-approved index cards? Worked for
him and me, a priceless observance of an actual FAR Part 145 repair facility
at work, worth every penny for the log entry. Purists impress me.... Had the
temptation to hit the IDENT button whilst he was straining through bifocals,
but dared not!
How 50-ohm impedance became the norm, where impedance of the atmosphere is etched
in stone by a higher power, and a 1/4-wave straight element is natural at 37,
well I beg off. Perhaps cuz it all works, or perhaps you know.... 75 works
for video hi-def TV with 2-way for nefarious purpose. The history of the decibel
may be similar whimsy? Not the convenient, additive/subtractive nondimensional
math, but Dr. Bell didn't get recognized as did Watt, Ohm, etc., and his
employer allegedly thought dividing by 10 (deci) was more practical. Purists
like me write "dB,"not "db." :D It's like in very current cell phone technology,
where despite awesome cleverness to me at least, nobody's been memorialized
for nuthin'. :x
Fred F.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=46993#46993
________________________________________________________________________________
| From: | "Bret Smith" <smithhb(at)tds.net> |
| Subject: | Capacitor for Z-13/8 |
Where can I purchase the capacitor (20-50KuFd) called out in Z13/8? I
cannot find it on the B&C site and wondered if the automotive variety would
work?
TIA
Bret Smith
RV-9A (91314)
Mineral Bluff, GA
www.FlightInnovations.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Capacitor for Z-13/8 |
>Where can I purchase the capacitor (20-50KuFd) called out in Z13/8? I
>cannot find it on the B&C site and wondered if the automotive variety
>would work?
>
>TIA
>
>Bret Smith
>RV-9A (91314)
>Mineral Bluff, GA
>www.FlightInnovations.com
B & C has a kit that includes all of the SD-8 filter, control
and ov protection parts cited in the drawing. You can give
them a call and see what the thing costs. I wasn't able to find
it quickly on their website either and don't have the time right
now.
If you just want the capacitor, check out Digikey
http://dkc3.digikey.com/PDF/T062/1099.pdf
The P10078 22KuF/40V is a good part for the task.
Also, look at 95F4431 at http://newark.com
This is a smaller diameter and much less expensive
part that would also do nicely.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: External Power and electrical system |
>
>
>Listers,
>
>I have been planning on adding external power to my system (one alternator,
>one battery, PMag IO360). My original design was pretty simple, hook it
>straight onto the battery such as one does when jump starting a car.
That works.
> Then I
>added a relay so that the external power terminals would not be hot when not
>connected to external power.
What is the added value? What risks are mitigated by this?
Is your external power INTENDED to crank an engine with a
compromised battery . . . or just to run electro-whizzies on
the ground, or just charge a battery, or just maintain a battery?
Settling on one of these design goals drives the size of your
hardware ranging from a tiny wall-wart charger and 24AWG connecting
leads up to 2AWG welding cable plugged in through a very fat connecto.
>Then some knowledgeable fellow builders told me
>that I should only use external power for starting the engine nothing
>else.
If that was their design goal, that's correct. What's your design
goal?
> Then some other knowledgeable builders told me that I could install a
>cigar lighter jack in parallel as an external power connector for recharging
>the battery.
Yup, that's another achievable design goal . . .
> Then there was the issue as to external power not being clean
>DC current and consequently liable to play havoc with some of my sensitive
>equipment.
If you have a battery on the bus any time ground power is
applied, then externally conducted noises are not an issue.
The battery is the airplane's best firewall against any and
all perturbations of bus voltage.
>Based on this I proceeded to design a circuit which would
>automatically disconnect all electricals except for the starter solenoid,
>current to the PMags and current to my fuel pump. Whereupon another
>knowledgeable person suggested that I should remember the KISS principle I
>may be over designing my system.
Again, depends on your design goals. What do YOU want this
ground power system to do for you?
>What do you guys suggest isolate my electrical system when external power
>is hot or just hook it up onto the battery via a relay?
Start with the article at:
http://aeroelectric.com/articles/grndpwr.pdf
This is typical of ground power jacks installed on
type certificated aircraft with a few AEC enhancements
added as described in the text.
This installation may be used for just about every purpose
other than battery maintenance because you need to close
a contactor to get connection between external power and
the battery.
Let's start with what you want the connection to do and
then tailor it to that task. Most of what you were told
is inaccurate and/or incomplete.
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: Ammeter Shunt |
Brian,
I'm one of those ignorant pilots who believes that an ammeter can provide
useful information while in flight, so I intend to install one along with a
voltmeter. I'm crafting my electrical system to do what I want it to do.
Do you, or anyone, know of one that is a digital center-zero meter? How
about a combo digital ammeter-voltmeter?
I plan to use hall effect devices and I'm going to mount them in at least
three places in the electrical system. I also plan to sample the voltage at the
same locations in the electrical system. I'm still deciding where those
locations will be, but they will likely be on the alternator lead, at the main
battery and at the standby battery. Other potential locations are the main bus
and the standby bus. I plan to route the sensor wires to a rotary selector
switch so as to be able to view any of the sensor locations on a single ammeter
and voltmeter. Too much effort and expense for little or no gain? Perhaps, but
it's the way I want it.
I believe that by using HE devices instead of shunts I would not have to
worry about making the shunt beefy enough to handle the starting loads. Is there
any advantage to using a shunt that I'm overlooking?
Has anyone found a good source for donut HE devices?
Thanks,
Stan Sutterfield
www.rv-8a.net
1. You can put one in series with any source of power (alternator,
generator, dynamo) and find out how much current it is delivering.
2. You can put one in series with a battery and see either its
charging current or loads when the charging current is insufficient
to carry all the loads (as in when the alternator is turning too
slowly or is off-line).
3. You can put one in series with a load or loads and see how much
current that device or devices demand from the system.
If you change the path so that the current no longer travels through
the shunt then you won't get any reading. Heck, you can put the shunt
permanently in the path to the battery so it always shows battery
current, even starting current. Then you can always see what is going
into and coming out of your battery. Just make sure your shunt is
beefy enough to handle the starting currents.
The above is true regardless of the number of alternators or
batteries in your system.
Bob makes a point that all this discussion is so you can craft your
electrical system to do what YOU want it to do. You may have
different reasons to measure current than Bob or I do. Bob doesn't
like the center-zero battery ammeter and I understand that. I have
developed new respect for this instrument in applications where one
will be running from battery power.
Here is another way of looking at it. If you have two sources of
power (alternators/dynamos) you are never going to be running your
loads off your battery. It is only needed to start the airplane. The
center-zero battery ammeter is almost useless in that system. OTOH if
you have a single alternator system and will depend on the battery to
get you to your destination should the alternator fail, you might
want to know what the loads are so you can estimate remaining battery
capacity. Now the center-zero ammeter is useful.
I have a boat with a 1000AH battery bank. That battery bank provides
all of the boat's power when I am at sea. I have to periodically
recharge it. I want to know how much capacity I have consumed so I
know how much is left and I want to know when it is fully charged. In
this application the battery ammeter/shunt is critical. No other tool
will suffice.
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Grounding lugs and transponder radiation |
On Jul 13, 2006, at 6:50 PM, europa flugzeug fabrik wrote:
>
>
>
> brian wrote:
>> ...If your transponder puts out a peak power of 200W we have:
>>
>> 200 = V^2 / 2000
>>
>> If we do the algebra we get:
>>
>> V = sqrt (200 * 2000) or 632V....
>>
>>
>
> That could be for what I know, but I thought we worked on 50 ohms
> by fiat. I have a musty, ancient xponder service manual I eBayd
> cheap for maybe giggles. To measure power, they had you kludge a
> commercial voltage detector together with a special diode, IN23B.
> Then you observed reply pulse trains on any whatever scope and
> counted P-P volts by graticule divisions. Volts squared, divided by
> 50 (into a dummy 50-ohm load) and thems peak watts. So only 100V
> P-P would work out to 200W.
You are correct for measuring the power at the output of a
transponder as the impedance there is 50 ohms. But we were not
talking about the impedance at the output of the transponder or of
the feedline. We were talking about the voltage at the tip of the
antenna.
The impedance of an antenna changes depending on where you feed it.
In a quarter-wave monopole (a "whip" antenna) the feedpoint impedance
at the base (the part nearest the ground plane) is something close to
50 ohms. (It is actually 36 ohms but that is close enough for
government work.) The impedance at the other end, where the little
ball is, is around 2000 ohms. The current in the conductor is at a
maximum near the base and a minimum at the end. Conversely the
voltage is at a minimum near the base and at a maximum near the free
end. If you consider the impedance to be the ratio of voltage to
current you can see that the impedance is constantly changing along
the shaft of the antenna. (This RF stuff is *WAY* different from the
DC stuff as voltage and current vary along a conductor or antenna
unlike DC were they stay the same.)
BTW, your comment about peak voltage caught a mistake of mine in that
I did my calculations in RMS volts when I should have done the
calculations in peak volts (RMS volts X 1.414 for a sine wave). So
the peak voltage at the tip of our transponder antenna with 200W
input is quite near 900V.
> Thats the purists approach, and funny that around 1990, I had my
> xponder check done by a crotchety old-timer. Hed ramp check
> also Mode C by observing similarly kludged, detected xponder output
> on what looked like his Dads old scope -- on wheels. For his
> selected altitude test points per Part 43, he had sketched the bit
> pattern on little index cards. Head cocked skyward to use his
> bifocals, holding said card up to the scope with round display.
> Pump vacuum at the plane, then run to the scope to check. He had
> to work fast, as permissible leak-down in the static sys at higher
> alts can cause up to multiple bits to flip Grey-code style (he
> seemed to rely on an observed time lag). Who needs very expensive
> equipment, when all you need are FAA-approved index cards? Worked
> for him and me, a priceless observance of an actual FAR Part 145
> repair facility at work, worth every penny for the log entry.
> Purists impress me.... Had the temptation to hit the IDENT butt!
> on whilst he was straining through bifocals, but dared not!
It is pretty cool that you can do it that way. You are just looking
at the pulses (RF on/off) and reading the code. I have done that as a
quick-and-dirty test with a cheap scope, a wire probe, and a crystal
diode configured as a shunt detector. You can get a pretty good
feeling for whether your transponder is working or not (assuming
there is an ATC RADAR close enough to interrogate the transponder
into a reply while on the ground).
> How 50-ohm impedance became the norm, where impedance of the
> atmosphere is etched in stone by a higher power, and a 1/4-wave
> straight element is natural at 37, well I beg off. Perhaps cuz it
> all works, or perhaps you know....
Ah, you have discovered the difference between physics and
philosophy. Physics just tells us that the feedpoint impedance at the
center of a dipole is 72 ohms. (A monopole being half a dipole is why
its impedance is 36 ohms.) It doesn't tell us *why* it is 72 ohms.
Philosophy is supposed to tell us why. The easiest answer is,
"because God wanted it that way," but that is too hard to get my tiny
brain around. I will just settle for trying to understand a few of
the relationships between the how, what, and where.
> 75 works for video hi-def TV with 2-way for nefarious purpose.
The answer is, "because the feedpoint impedance at the center of a
dipole is 72 ohms." Once you make a wire intended to feed that
impedance you may as well use it for something else too. If you have
a coax with a characteristic impedance of 75 ohms you have to
terminate it at 75 ohms to minimize reflections. Everyone else may as
well use that impedance as well. And then people started playing with
monopole antennas and found 50 ohms to be more convenient so we got
another kind of coax we could use with lots of different things.
> The history of the decibel may be similar whimsy? Not the
> convenient, additive/subtractive nondimensional math, but Dr. Bell
> didn't get recognized as did Watt, Ohm, etc., and his employer
> allegedly thought dividing by 10 (deci) was more practical.
No, the official unit is the Bell, just like the other official units
are things like the watt, volt, ampere, coulomb, etc. It is just that
sometimes it is easier to measure things with multipliers in the
units like micro-volt, milliampere, kilowatt, and decibel.
> Purists like me write "dB,"not "db." :D
Well, that is the way it is supposed to be written. Just like Hertz
is Hz, not hz. Mega-Hertz is MHz, not mhz.
> It's like in very current cell phone technology, where despite
> awesome cleverness to me at least, nobody's been memorialized for
> nuthin'. :x
There hasn't been a lot that is new in radio theory. The "new" stuff
is just clever application of what we have known for a long time. It
is now with digital signal processing we can do some things that we
knew could be done but couldn't do effectively using the technology
at hand back when the math showed the possibility.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: Ammeter Shunt |
--- MIME Errors - No Plain-Text Section Found ---
A message with no text/plain MIME section was received.
The entire body of the message was removed. Please
resend the email using Plain Text formatting.
HOTMAIL is notorious for only including an HTML section
in their client's default configuration. If you're using
HOTMAIL, please see your email application's settings
and switch to a default mail option that uses "Plain Text".
--- MIME Errors No Plain-Text Section Found ---
________________________________________________________________________________
| Subject: | Mic audio ground - PMA8000B |
Say - on the PMA7000, 8000 or GMA340 audio panels...none of them have a
dedicated return (ground) for the Mic Gnd (used on SL30/40 & GNS480). I
would assume the 'dedicated' returns are all connected together
internally - and are there for ease of install - i.e. to pin 10,11.....
Anyone have some advice as to what to hook up the Mic Gnd to on a
PMA8000 series audio panel?
-------------------------
Say - I noticed that the PMA7000 vs the PMA8000 and GMA340 have opposite
convention on the tip and middle tip of the audio plugs - for L/R use.
Obviously the input tip/middle tips are changed as well - so pass thru
is just fine.
Is there actually a convention used? - just curious....
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 14, 2006, at 10:37 AM, Ralph E. Capen wrote:
> Vision Microsystems uses one for their current detection (uses four
> wires and a shield).......I have one installed and was thinking
> about something along the lines of what you're doing......
>
> My question is where are you getting the rotary switch to switch
> the four wires? (I would gang all of the shields)
You may find that you only need to switch one or maybe two wires. At
least one wire is power in and one other is power ground. You can
probably leave those hooked up all the time and not switch them. I
would guess that one of the other wires is output and one is signal
ground or maybe it has a differential output.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Mic audio ground - PMA8000B |
On Jul 14, 2006, at 11:11 AM, John Tvedte wrote:
>
> Anyone have some advice as to what to hook up the Mic Gnd to on a
> PMA8000 series audio panel?
Insulate the mic jack from the airframe. Return the shell to the
ground at the audio panel. All your mic inputs will return to this
same common ground at the audio panel.
Do not return your mic grounds to the single-point power ground at
the firewall.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: Ammeter Shunt |
On Jul 14, 2006, at 10:03 AM, Speedy11(at)aol.com wrote:
> Brian,
> I'm one of those ignorant pilots who believes that an ammeter can
> provide useful information while in flight, so I intend to install
> one along with a voltmeter. I'm crafting my electrical system to
> do what I want it to do.
Well, if only ignorant pilot believe that an ammeter provides useful
information then I am an ignorant pilot too.
> Do you, or anyone, know of one that is a digital center-zero
> meter? How about a combo digital ammeter-voltmeter?
There are a lot of companies that make volt/ammeter combination
gauges. I have not seen an analog center-zero ammeter that is also a
combination volt/ammeter. The digital ones will usually show a sign
on the current indication thus allowing you to see the magnitude of
both charge and discharge. You should be able to find either analog
or digital to suit your taste.
> I plan to use hall effect devices and I'm going to mount them in at
> least three places in the electrical system. I also plan to sample
> the voltage at the same locations in the electrical system. I'm
> still deciding where those locations will be, but they will likely
> be on the alternator lead, at the main battery and at the standby
> battery. Other potential locations are the main bus and the
> standby bus. I plan to route the sensor wires to a rotary selector
> switch so as to be able to view any of the sensor locations on a
> single ammeter and voltmeter. Too much effort and expense for
> little or no gain? Perhaps, but it's the way I want it.
Then that is how you should do it. It is your airplane and you should
equip it the way you like.
> I believe that by using HE devices instead of shunts I would not
> have to worry about making the shunt beefy enough to handle the
> starting loads. Is there any advantage to using a shunt that I'm
> overlooking?
Shunts are more accurate. When there is zero voltage across the
terminals of a shunt there is definitely no current through the
shunt. Hall effect devices exhibit offset error and can be affected
by other nearby conductors carrying current. But in most cases they
are just fine.
Bipolar hall effect sensors usually have their output midway between
ground and the supply voltage (typically +5V) when they are sensing
zero current. So +2.5V really means zero current. You just need to
calibrate your indicator accordingly.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | building a hall-effect ammeter |
FYI: http://www.siliconchip.com.au/cms/A_30551/article.html
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Brian Meyette" <bmeyette(at)gmail.com> |
| Subject: | FW Bell RSS-100-A hall effect sensor |
Does anyone know a source of this sensor, or an equivalent? I need it for
current flow measuring on BMA EFIS/One. Newark no longer lists them - just
the 200a. Allied lists them, but none in stock and they tell me 18 week
delay to get one. None of the other places I checked list them at all;
DIgikey, Mouser, onlinecomponents, and several others listed on the FW Bell
site. I realize BMA has theirs, but it's $100 and these FW Bell ones are
$43; quite a difference.
--
________________________________________________________________________________
| From: | "Dale Ensing" <densing(at)carolina.rr.com> |
| Subject: | Re: building a hall-effect ammeter |
Brian,
Is this available as a kit?
Dale Ensing
>
> FYI: http://www.siliconchip.com.au/cms/A_30551/article.html
>
> Brian Lloyd
>
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: building a hall-effect ammeter |
On Jul 14, 2006, at 3:20 PM, Dale Ensing wrote:
>
>
> Brian,
> Is this available as a kit?
I don't know. I just found the article. You probably need to use the
info in the article to find out.
> Dale Ensing
>
>
>> yak(at)lloyd.com>
>>
>> FYI: http://www.siliconchip.com.au/cms/A_30551/article.html
>>
>> Brian Lloyd
>>
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Grounding lugs and transponder radiation |
In a message dated 7/12/06 7:45:08 PM Eastern Daylight Time, n3eu(at)comcast.net
writes:
> > The signal is radiated only from the shaft of the antenna.
>
> A couple theoretical texts I have suggest it radiates only from the base
of
> the antenna. Has to do with 90-deg phase lag, current and voltage, I
think.
> The vertical element is there merely to resonate.
>
> Dunno also, but the ball has been alleged to be either a capacity hat, or
to
> have proverse effect on radiating pattern. One such allegation came from
a
> retired, aircraft antenna engineer I know. But he thinks my questions are
> often inane! [Wink]
>
> Fred F.
=================================
Fred - Group:
If people think that the ball does not radiate cut it off. Better yet TOUCH
it and see if you get an RF Burn! Want to get a bit more scientific? Make up
or obtain a second antennas and check the SWR with and without the ball. SWR
will be higher without the ball.
As I stated before ... If it is metal and it is attached to the antenna it is
part of the radiating medium of the antenna.
As far as Lead Vs Lag ... Current Vs Voltage ... ELI the ICE man ... [The
previous are all theories taught in electronics and physics.] Who gives a
Dittlie-Womp. That is all theory in Capacitive Reactance - Inductive Reactance
and
Wave Length. It only matters when obtaining the correct impedance for
matching the antenna to the transmission line and the transmission line to the
transponder (in this case). Bottom Line ... IT RADIATES. Check out SMITH Charts
and that other guy's charts I can't remember right now.
It is NOT a capacitive hat ... It is NOT a loading coil ... Again as I stated
it is for eliminating Corona Effect and the dissipation of static.
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: External Power and electrical system isolation |
In a message dated 7/13/06 3:59:57 PM Eastern Daylight Time,
michele.delsol(at)microsigma.fr writes:
> What do you guys suggest isolate my electrical system when external power
> is hot or just hook it up onto the battery via a relay?
>
> Thanks,
> Michele Delsol
> RV8 Fuselage
==========================
Michele:
The first question you have to ask yourself is: "What do I want the external
power for?"
If your answer is STARTING then all that is required is a connection - relay
to act as a MASTER RELAY and supply power to the Starter Relay and conversely
to the STARTER. Isolating the rest of the panel and electronics. You can get
that circuit from any GA manual Cessna, Piper or Grumman. That to me is the
K.I.S.S. M.E. principal. Now if you want a THREE function power hookup source
for:
1 - Running a handheld or GPS
2 - Running your electronics for testing, or
3 - Doing a LOW LEVEL charge, such as charging the battery using a solar
panel ... The just hook up a cigarette lighter directly to the battery.
This is the system I have hooked up in the RV-6A.
It is GREAT when you have an electrical problem and have to shut down the
MASTER. It gives you power for the GPS [Navigation] and a handheld
[Communication]. Oh, did you remember to install a quick disconnect for the antenna
so you
can hook up the handheld?
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | microphone noise |
Good day.
I've tried a couple of headsets but I have a lot of static whenever I
key the transmit button with the headset microphone plugged in. I can
hear it on my headset and it is being transmitted. No static if I key it
with the mic unplugged. So it would seem that the mic is picking up
cockpit noise. However clasping my hand over the boom mic or changing
its orientation does not change the static which seems to suggest it is
not cockpit noise. Any suggestions?
This is an Icomm A-200 radio and an intercom but bypassing the intercom
with its "pilot/all" switch doesn't change anything. The headset jacks
are mounted in a plastic box. Separate shielded wires are used for the
mic and the earphones with the shields carrying the grounds.
thanks
Ken
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: microphone noise |
Ken wrote:
>
> Good day.
>
> I've tried a couple of headsets but I have a lot of static whenever I
> key the transmit button with the headset microphone plugged in. I can
> hear it on my headset and it is being transmitted. No static if I key
> it with the mic unplugged. So it would seem that the mic is picking up
> cockpit noise. However clasping my hand over the boom mic or changing
> its orientation does not change the static which seems to suggest it
> is not cockpit noise. Any suggestions?
>
> This is an Icomm A-200 radio and an intercom but bypassing the
> intercom with its "pilot/all" switch doesn't change anything. The
> headset jacks are mounted in a plastic box. Separate shielded wires
> are used for the mic and the earphones with the shields carrying the
> grounds.
>
> thanks
> Ken
If you have a noisy cockpit, covering the mic with your hand probably
won't make much difference.
Is it electronic static or cockpit noise?
Does it change in pitch with engine rpm? (ignition or alternator)
Is it quiet it you key the mic with the master & all accessories on but
without the engine running? (cockpit noise)
If it's there with the engine & all other accessories off, you might
have radio problems.
If it's there but quieter & no pitch change with the engine idling, it's
probably cockpit noise.
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Re: External Power and electrical system |
> >
> >
> >Listers,
> >
> >I have been planning on adding external power to my system (one alternator,
> >one battery, PMag IO360). My original design was pretty simple, hook it
> >straight onto the battery such as one does when jump starting a car.
>> Then I added a relay so that the external power terminals would not be hot
when not connected to external power.
Michele,
Earlier you said that you intended to place your battery on the right side behind
the firewall. It seems to me, that in this location, you can access the battery
on your RV8 by simply opening the front baggage door and reaching down.
With this location, why add weight and complexity when there is such a simple
and obvious solution? What am I missing?
Charlie Kuss
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: microphone noise |
In a message dated 7/15/06 7:55:03 AM Eastern Daylight Time,
klehman(at)albedo.net writes:
> Good day.
>
> I've tried a couple of headsets but I have a lot of static whenever I
> key the transmit button with the headset microphone plugged in. I can
> hear it on my headset and it is being transmitted. No static if I key it
> with the mic unplugged. So it would seem that the mic is picking up
> cockpit noise. However clasping my hand over the boom mic or changing
> its orientation does not change the static which seems to suggest it is
> not cockpit noise. Any suggestions?
>
> This is an Icomm A-200 radio and an intercom but bypassing the intercom
> with its "pilot/all" switch doesn't change anything. The headset jacks
> are mounted in a plastic box. Separate shielded wires are used for the
> mic and the earphones with the shields carrying the grounds.
>
> thanks
> Ken
============================
Ken:
You have a good question ... Problem their ... My next question in the
diagnosis would be:
Is the static their when you use any other Headset - Mic Jacks?
If not then the problem is only associated with the Mic Jack you are using.
If the problem still exists on ALL jacks then you have to go back to the
common points - PTT Switch, Intercom and Radio.
Barry
"Chop'd Liver"
"When all the possibilities are eliminated then the only thing left is the
probability"
________________________________________________________________________________
| From: | Brian Lloyd <brian-yak(at)lloyd.com> |
| Subject: | Re: External Power and electrical system |
It can be difficult to effectively asses one's needs when doing an
initial design. For the most part, whenever I have said to myself, "I
won't need that," I have found that indeed I eventually needed "that".
As others have said, there are three reasons for ground power:
1. starting the engine when the battery charge is too low;
2. to operate the electrical equipment on the ground without
discharging the battery;
3. to charge the battery.
If I were going to craft a ground-power plug I would ensure that it
was usable for all three functions.
Now for an anecdote. At OSH in 2000 I was supposed to fly my CJ6A in
the mass warbird formation on Friday. (I had already flown on opening
day on Wednesday as I recall.) At the proper time we hopped in our
airplanes. It was at that moment I discovered that someone had been
in my airplane and had turned on every switch, including the battery
master. My battery was dead. If I had had a ground power plug I might
have been able to put an initial charge on the battery and start the
engine and still fly in the shoe. As it was, I couldn't.
I considered trying to get some jumpers in there but, as the battery
was back in the empennage under the baggage compartment floor, it was
inconvenient and a rogue jumper cable was likely to do damage to
something. So I very carefully pulled the battery and hauled it up to
the warbird maintenance area were we were able to put it on a charger.
Several hours later the battery was charged and I was in the process
of reinstalling it. I was being extremely careful to keep the
terminal from touching any of the control cables but it was dark back
in there. I had avoided the rudder and elevator control cables but
missed seeing the much smaller trim cable. Of course I managed to get
the trim cable across the battery terminals. The trim cable failed
with a most satisfactory flash and bang. (Yes, the damned thing
literally exploded in my face.) I bashed my head against a bulkhead
and uttered the immortal words. I managed to extricate my temporarily-
blinded eyes from the baggage compartment only to have the pilot next
to me say, "So Sparky, having a bit of trouble, are we?" From then on
my call-sign was "Sparky".
So, yes, I want my ground power plug to be able to do it all. I
consider it to be a safety issue now.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | luckymacy(at)comcast.net (lucky) |
| Subject: | Help needed: continued strobe noise & weak radio |
I have two "comm" issues that I haven't been able to debug to completion yet.
I'm using an Xcom 760 radio with their pre-made harness.
1) I still hear my strobes in my headset even when they are grounded with the radio
ground and even when I put power noise filters on. However, the Radio Shack
noise filters reference on Bob's web site were reported to me to be no longer
carried by them. So I used the only ones I could find locally which were
sold by Pep Boys and the capacitor was 4700 uF instead of 2200 uF like Radio Shack
apparently was.
More specifically, the strobe noise is relatively faint until I select the Push
to Talk button. Then it gets pretty loud. Some feedback going on there. Looking
for ideas from this list.
Should the capacitor specs have made a big difference on the effectiveness overall
of the noise filter? It made no measurable difference regardless of whether
I installed it just before the radio or out at the strobe's power supply just
before the AC +14v entered the power supply. I even reversed direction of
the filter and it didn't matter one iota. Really bummed out about this turn of
events since I thought they'd at least have made some observable difference
based upon stuff in the archives.
2) The second overall problem is that the radio still is reported to me by other
pilots as weak when I get much beyond a couple of miles and breaks up in the
pattern a lot. I'm guessing it's because I can't put out enough consistent
power to break their squelch consistently. When on the actual ground taxiing
around, if there's a crown or "hill" between me and another airplane on the ground
forget it. They can't hear me or vice a versa.
When I check my radio with a handheld on the ground I seem to be just fine for
the relatively close distances I've tried even when the plane is inside an open
hangar and come in just as loud on the hand held as anyone else is. It also
doesn't matter whether or not the strobes are powered on or not as far as whether
or not the range/strength improves. ie, even with them off the lack of range
doesn't improve.
I swapped the cable between the radio and the antenna and it made no difference.
I bought my antenna from Van's but didn't do any kind of post install test
besides checking it out with my comm radio and a hand held and it seemed fine
at the time...
Instead of using RG-58 I bought two pre-made RG-400 cables. What should the center
conductor's resistance read end to end? ~58 Ohms, right? My actual reading
bounces all over the place no matter how stable I am in trying to read it.
Strange. Also, there doesn't seem to be a short between the center conductor
and the plug itself when I check it with a multimeter so I'm guessing the plugs
were installed correctly.
Things I have left to try is just buy a pre-made 12' RG-58 cable from radio shack
and try it instead of the RG-400 cables. Also, I don't have a spare comm antenna
but I think RS carries a replacement 800 Mhz scanner antenna with the right
BNC connector that I can just temporarily use just to see if makes any difference
at all.
Any ideas from the list?
________________________________________________________________________________
| From: | Hopperdhh(at)aol.com |
| Subject: | Re: Help needed: continued strobe noise & weak radio |
In a message dated 7/15/2006 10:05:43 P.M. Eastern Daylight Time,
luckymacy(at)comcast.net writes:
Instead of using RG-58 I bought two pre-made RG-400 cables. What should the
center conductor's resistance read end to end? ~58 Ohms, right? My actual
reading bounces all over the place no matter how stable I am in trying to
read it. Strange. Also, there doesn't seem to be a short between the center
conductor and the plug itself when I check it with a multimeter so I'm guessing
the plugs were installed correctly.
No, with a DC meter the cable should read very low resistance from end to
July 04, 2006 - July 15, 2006
AeroElectric-Archive.digest.vol-fv