Today's Message Index:
----------------------
1. 05:46 AM - Re: OV B-lead Relay (bob noffs)
2. 05:59 AM - Re: OV B-lead Relay (bob noffs)
3. 07:19 AM - Re: OV B-lead Relay (johnbright)
4. 09:01 AM - Re: Re: OV B-lead Relay (Robert L. Nuckolls, III)
5. 09:50 AM - Re: Re: OV B-lead Relay (bob noffs)
6. 09:56 AM - Re: Re: OV B-lead Relay (Robert L. Nuckolls, III)
7. 10:41 AM - Bose Headset Replacement Plug ()
8. 11:16 AM - Re: Re: OV B-lead Relay (Charlie England)
9. 11:36 AM - Re: Bose Headset Replacement Plug (Eric Page)
10. 11:38 AM - Re: Bose Headset Replacement Plug (Eric Page)
11. 12:29 PM - Re: OV B-lead Relay (Dan Fritz)
12. 01:07 PM - Re: Re: OV B-lead Relay (Finn Lassen)
13. 05:24 PM - Re: Re: OV B-lead Relay (Robert L. Nuckolls, III)
14. 07:02 PM - Re: Re: OV B-lead Relay (Robert L. Nuckolls, III)
15. 07:16 PM - Re: Re: OV B-lead Relay (Robert L. Nuckolls, III)
16. 07:27 PM - Re: Alternator Mod to External Control (Robert L. Nuckolls, III)
17. 08:49 PM - Re: OV B-lead Relay (Dan Fritz)
18. 08:55 PM - Re: Alternator Mod to External Control (Dan Fritz)
19. 10:55 PM - Re: Alternator Mod to External Control (Dan Fritz)
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| Subject: | Re: OV B-lead Relay |
hi bob,
you posted on 8/23/18 on the subject of ''crowbars''. it looks like the
link is a dead end now but maybe i have the receipt of a hx on ebay in my
account.
bob noffs
On Mon, Apr 20, 2020 at 1:34 PM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 06:44 AM 4/20/2020, you wrote:
>
> there is a thread in the past 2 yrs. about ov disconnecting the b lead.
> bob posted a link to a 200 amp relay that i did use to wire an ov
> disconnect into my b lead. is it being said now that that is a bad idea?
i
> always expected i would fry the alternator, i only need the disconnect on
ce.
> =C3=82 bob noffs
>
>
> Refresh my memory . . . what kind of relay
> made it into your system? Can you give
> me a date on the thread?
>
>
> Bob . . .
>
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| Subject: | Re: OV B-lead Relay |
bob, all i could find of it was a pic. it i black plastic. at the time of
the post connector types was in question. yp180, yp-100-12 and 12v-200a are
printed on the unit. it is for auto, continuous duty. it has 3/16 or 1/4''
lugs and is rated 200 amps.
bob noffs
On Tue, Apr 21, 2020 at 7:43 AM bob noffs <icubob@gmail.com> wrote:
> hi bob,
> you posted on 8/23/18 on the subject of ''crowbars''. it looks like the
> link is a dead end now but maybe i have the receipt of a hx on ebay in my
> account.
> bob noffs
>
> On Mon, Apr 20, 2020 at 1:34 PM Robert L. Nuckolls, III <
> nuckolls.bob@aeroelectric.com> wrote:
>
>> At 06:44 AM 4/20/2020, you wrote:
>>
>> there is a thread in the past 2 yrs. about ov disconnecting the b lead.
>> bob posted a link to a 200 amp relay that i did use to wire an ov
>> disconnect into my b lead. is it being said now that that is a bad idea?
i
>> always expected i would fry the alternator, i only need the disconnect o
nce.
>> =C3=82 bob noffs
>>
>>
>> Refresh my memory . . . what kind of relay
>> made it into your system? Can you give
>> me a date on the thread?
>>
>>
>> Bob . . .
>>
>
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| Subject: | Re: OV B-lead Relay |
bobnoffs wrote:
> ... yp180, yp-100-12 and 12v-200a are printed on the unit...
https://www.ebay.com/c/20012698760
--------
John Bright, RV-6A, at FWF, O-360
Single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495939#495939
Attachments:
http://forums.matronics.com//files/12v24v_dc200a_high_power_car_relay_112.jpg
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| Subject: | Re: OV B-lead Relay |
At 09:18 AM 4/21/2020, you wrote:
><john_s_bright@yahoo.com>
>bobnoffs wrote:
> > ... yp180, yp-100-12 and 12v-200a are printed on the unit...
>
>
>https://www.ebay.com/c/20012698760
>
Yeah, this is the one I did a tear-down on
but for the life of me, I can't find the
pictures in the archive. I'm skeptical of
the 200A rating and to be sure, the single
break contact gap is unsuitable for a
b-lead disconnect.
Bob . . .
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| Subject: | Re: OV B-lead Relay |
bob, do you have a link or part # for something that would work for b lead
disconnect?
how unsuitable is this 200 amp relay? i mean, are the number of cycles
that it will function be limited or will it be shot after its first cycle?
if i use it once i am going to have an alternator to replace, why not the
relay too? it is not likely this thing is ever likely to see even one use.
your take on this would be appreciated.
bob noffs
On Tue, Apr 21, 2020 at 11:09 AM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 09:18 AM 4/21/2020, you wrote:
>
> john_s_bright@yahoo.com>
> bobnoffs wrote:
> > ... yp180, yp-100-12 and 12v-200a are printed on the unit...
>
>
> https://www.ebay.com/c/20012698760
>
>
> Yeah, this is the one I did a tear-down on
> but for the life of me, I can't find the
> pictures in the archive. I'm skeptical of
> the 200A rating and to be sure, the single
> break contact gap is unsuitable for a
> b-lead disconnect.
>
>
> Bob . . .
>
Message 6
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| Subject: | Re: OV B-lead Relay |
At 11:39 PM 4/20/2020, you wrote:
>
>Hi Bob, I've been doing some searching and found
>a couple of tutorials on modifying an alternator
>to external regulation and am considering
>whether to attempt the mod. While searching, I
>also found an article of yours from Feb 2004
>(=9CLoad Dump=9D Damage to Alternators with
>Built-in Regulators). Were you ever able to get
>test results from your proposed Z-24 with a TVS diode installed?
>
>Dan
That's been awhile back . . . I don't recall
that I ever got to explore that option on the
bench. There's a LOT of energy sourcing the
output of a runaway alternator. TVS are
transient suppressors: High current, rapidly
rising voltage but of limited duration hence
low energy.
The runaway alternator is suited to being
jury-rigged into a arc welder!
I do recall a visit to Motorcar Parts of
America facilities in Tijuana Mexico in 2004
where I witnessed the extreme load-dump being
impressed on an alternator under test.
The narrative of that trip can be found
on page 3-6 of this document
https://tinyurl.com/y7qzlfw6
We cannot know the source for alternators
popular with the Van's crowd back then
but common sense suggests that immunity
from load-dump effects are pretty much
the gold standard. It's not hard to do . . .
so why not do it? Your competition does.
I have a design proposal on the hard drive
that takes a little different approach
to b-lead management of an ov condition.
This approach drive the bus through a
diode capable of carrying full alternator
output. Instead of attempting to BREAK
the b-lead, I simply short it to ground
with a fat FET. In a mater of microseconds,
b-lead voltage is reduced to millivolts.
Since the field is sourced from the b-lead,
the runaway alternator is simultaneously
deprived of field excitation. The whole
thing simply relaxes. The cited diode
prevents reflection of the crowbar
on the rest of the airplane.
Intuitively, this has to work. Best
yet, it would prevent the alternator's
suicide attempt.
I didn't push this idea forward . . . it
seemed like a lot of monkey-motion to
avoid the simple mod to run the
alternator with an external regulator.
If anyone would like to explore the b-lead,
crowbar method for bringing an internally
regulated alternator to heel, I'll publish
the sketches.
Bob . . .
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| Subject: | Bose Headset Replacement Plug |
Greetings Ya'All,
I am still trying to find out what color wire connects to the phone jack
lugs of the Bose A20 "GA wire harness".
>From the recommendations you gave from my last post on this subject I tried
to do a continuity check of the wires to the phone plug so as to determine
what color wires went to the jack lugs however the wires were broken inside.
I then tried to dig out the plastic molded on cable end and trace the wire
colors to the plug however as the molded on plastic was removed it pulled
off the colored insulation from the wires so now I.and my headset.are dead
in the water because I do not know what wire is supposed to go where.
So I need to know what color wires (red/black/white/blue/green) are supposed
to be soldered on to the replacement Neutrik NP3X plug's three lugs
(tip/center/ring) and
If you can help I would be greatly appreciative since Bose wants 300 bucks
for a replacement cable.
THANKS!!!!
Bill
Message 8
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| Subject: | Re: OV B-lead Relay |
On 4/21/2020 11:52 AM, Robert L. Nuckolls, III wrote:
> At 11:39 PM 4/20/2020, you wrote:
>>
>> Hi Bob, I've been doing some searching and found a couple of
>> tutorials on modifying an alternator to external regulation and am
>> considering whether to attempt the mod. While searching, I also
>> found an article of yours from Feb 2004 (Load Dump Damage to
>> Alternators with Built-in Regulators). Were you ever able to get
>> test results from your proposed Z-24 with a TVS diode installed?
>>
>> Dan
>
> That's been awhile back . . . I don't recall
> that I ever got to explore that option on the
> bench. There's a LOT of energy sourcing the
> output of a runaway alternator. TVS are
> transient suppressors: High current, rapidly
> rising voltage but of limited duration hence
> low energy.
>
> The runaway alternator is suited to being
> jury-rigged into a arc welder!
>
>
> I do recall a visit to Motorcar Parts of
> America facilities in Tijuana Mexico in 2004
> where I witnessed the extreme load-dump being
> impressed on an alternator under test.
>
> The narrative of that trip can be found
> on page 3-6 of this document
>
> https://tinyurl.com/y7qzlfw6 <https://tinyurl.com/y7qzlfw6>
>
> We cannot know the source for alternators
> popular with the Van's crowd back then
> but common sense suggests that immunity
> from load-dump effects are pretty much
> the gold standard. It's not hard to do . . .
> so why not do it? Your competition does.
>
> I have a design proposal on the hard drive
> that takes a little different approach
> to b-lead management of an ov condition.
>
> This approach drive the bus through a
> diode capable of carrying full alternator
> output. Instead of attempting to BREAK
> the b-lead, I simply short it to ground
> with a fat FET. In a mater of microseconds,
> b-lead voltage is reduced to millivolts.
> Since the field is sourced from the b-lead,
> the runaway alternator is simultaneously
> deprived of field excitation. The whole
> thing simply relaxes. The cited diode
> prevents reflection of the crowbar
> on the rest of the airplane.
>
> Intuitively, this has to work. Best
> yet, it would prevent the alternator's
> suicide attempt.
>
> I didn't push this idea forward . . . it
> seemed like a lot of monkey-motion to
> avoid the simple mod to run the
> alternator with an external regulator.
>
> If anyone would like to explore the b-lead,
> crowbar method for bringing an internally
> regulated alternator to heel, I'll publish
> the sketches.
>
>
> Bob . . .
>
My admittedly sometimes faulty memory of the whole 'load dump' situation
two decades ago was that guys were flipping their alt switches/breakers
(which controlled the B lead contactor) while the alt was under load,
and killing the alt. IIRC, after multiple incidents like that, the OV
module/contactor circuit became a lot harder to find in the AEC docs.
My solution is the He Haw Solution: 'If it hurts when you do that, DON'T
DO THAT!'
Here's my take: If I operate the IR alternator just like it's operated
in the car, I'll never have a load dump event. If I use an OV module
that is relatively immune to 'false positives', along with a relatively
robust B lead contactor, the only penalty I see is carrying a few ounces
of extra weight for the contactor. The contactor will never operate
unless the regulator has failed (in an OV mode), in which case the 'load
dump' issue is already moot.
This lets me use an off the shelf, *very inexpensive*, available at any
auto supply, alternator. It won't be as reliable as a B&C, but based on
anecdotal evidence from RV-x owners, a *lot* more reliable than a Plane
Power. And I'll have about $500 left over to buy fuel. (Replacement
alts, if ever needed, will be free.) If I do have to replace the alt
while away from home, no mod to the alt is needed, and replacement can
happen on the ramp with only a couple of wrenches.
I have had several different 'lives' as an electronics tech, from home
electronics to pro sound, to industrial gear. Even though I'd consider
myself to be well above average in qualifications, I trust an 'as-built'
alternator to be more reliable than one that I've modded.
My opinion is that if any update is made, it would be to redesign the OV
module to reduce the risk of 'false positive' nuisance trips, and retain
the B lead relay. Perhaps do a little testing on whether a single
contact automotive cube relay can reliably open the B lead, *once*, as
Bob Noffs mentioned, and treat the relay as if it's a fusible link.
Realistically, if the OV module fires at ~16V, how much energy is really
there? How much delay will there be from hitting the voltage threshold
to the contacts opening? If we used a 100A cube relay (which *should*,
by definition, be able to actively control a 100A load), will it really
be stressed by 60-70 amps at ~20V? Or will the voltage (and energy) be
much higher by the time the contacts actually start to open? I realize
that voltage will spike upward as the contacts separate, but will it be
bad enough in a 'one shot' environment to weld the contacts?
Charlie
--
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Message 9
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| Subject: | Re: Bose Headset Replacement Plug |
Red (positive) and black (ground) will almost certainly be power to the he
adset electronics.=C2- White, blue and green are probably left, right and
ground for audio.=C2- The correlation of those colors is anyone's guess,
but they're easy to figure out.
You may be able to determine audio ground by a continuity check with power
ground (black).=C2- Left and right are easily determined by experimentati
on with a 1.5V AA or AAA battery (do NOT use a 9V!).=C2- Put the headset
on, then hold one wire on the "-" pole of the battery and tap another wire
on the "+" pole.=C2- You'll hear a scratching noise in the ear that's fed
by that wire.
Eric
On Tuesday, April 21, 2020, 11:02:28 AM PDT, <billhuntersemail@gmail.co
m> wrote: I am still trying to find out what color wire connects to the ph
one jack lugs of the Bose A20 =9CGA wire harness=9D
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| Subject: | Re: Bose Headset Replacement Plug |
Right after posting that last suggestion, I opened the weekly email from K
itplanes magazine and found this article about repairing the cable on Bose
headsets!
https://www.kitplanes.com/crimping-style/
Eric
On Tuesday, April 21, 2020, 11:02:28 AM PDT, <billhuntersemail@gmail.co
m> wrote: I am still trying to find out what color wire connects to the ph
one jack lugs of the Bose A20 =9CGA wire harness=9D
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| Subject: | Re: OV B-lead Relay |
One of the things I've always wondered about with Z-24 was the impact of the B-lead
contactor opening when the field switch is opened. This appears to negate
any positive influence of having a progressive switch for the master contactor
and field power. What do you all think of the adjustment propose in the attached
to Z-24 to re-introduce the goodness of the progressive switch while keeping
the full protection offered by Z-24. One could also consider putting a
TVS across the B-lead between the B-lead contactor and the alternator in an attempt
to save the regulator if a nuisance trip of the Overvoltage protection were
to take place.
thoughts? Dan
P.S. did this "old school" with whiteout and a pencil, excuse the messiness...
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495948#495948
Attachments:
http://forums.matronics.com//files/modz24_364.jpg
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| Subject: | Re: OV B-lead Relay |
On 4/21/2020 12:52 PM, Robert L. Nuckolls, III wrote:
> This approach drive the bus through a
> diode capable of carrying full alternator
> output. Instead of attempting to BREAK
> the b-lead, I simply short it to ground
> with a fat FET. In a mater of microseconds,
> b-lead voltage is reduced to millivolts.
> Since the field is sourced from the b-lead,
> the runaway alternator is simultaneously
> deprived of field excitation. The whole
> thing simply relaxes.
Is it possible that some car alternators have built-in filtering
(capacitor) in the internal regulator that would extend microseconds to
milliseconds or more?
Looking at the output windings as a coil, wouldn't shorting them result
in a huge spike destroying the rectifier diodes or would all the energy
stored in the coil be dissipated as heat?
Shorting B+ to ground would put the rectifier diodes in the shorted
path. Any chance that the rectifier diodes would be destroyed?
Finn
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| Subject: | Re: OV B-lead Relay |
>
>Is it possible that some car alternators have built-in filtering
>(capacitor) in the internal regulator that would extend microseconds
>to milliseconds or more?
>
>Looking at the output windings as a coil, wouldn't shorting them
>result in a huge spike destroying the rectifier diodes or would all
>the energy stored in the coil be dissipated as heat?
>
>Shorting B+ to ground would put the rectifier diodes in the shorted
>path. Any chance that the rectifier diodes would be destroyed?
No, no and no. The alternator is simply modeled
as a current limited source of power the magnitude
of which can be controlled by adjustment to
input RPM and field current.
Whether you tax the alternator at nameplate ratings
in a normal energy production mode -OR- throw
a dead short across the b-lead . . . the current
that will flow in the alternator's output hardware
will be the same . . . at or slightly above nameplate
rating of the alternator.
Unlike a really fat capacitor or a battery, the
b-lead fault current is limited by the alternator's
magnetics.
Even if the field were continuously excited a
dead short on the b-lead would only produce a
STEADY current flow at or above nameplate ratings.
That condition WOULD continue to warm the diodes
and stator windings as if the machine were producing
useful power. Given that the field on an internally
regulated alternator is SUPPLIED from the b-lead,
hitting the b-lead with a short not only shunts
a nominal current source to ground, it deprives
the alternator of it's field excitation. The
current that flows would be very short and things
would settle down to what ever current is generated
by residual field flux. The whole thing is brought
gracefully to a low energy state.
That's an interesting bench experiment I'm
planning to conduct . . . I've attached
a sketch of what the system would look like.
The series diode would drop the alternator
output by a volt or so . . . no big deal.
Everything on the panel is lit up. This
'crowbar' needs to use a really low resistance
FET (easy to get). If you used an SCR to
effect the short, the SCR still drops about
a volt in the on-state. 1 volt on an ND
alternator at 10,000 rpm will generate a LOT
of snort.
Our short needs to take the b-lead down to
millivolt levels and hold it there.
But given the ease with which the alternator
can be modified into a real 'aircraft'
part, any notions of a Z24 update are not
so interesting.
Bob . . .
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| Subject: | Re: OV B-lead Relay |
>>My admittedly sometimes faulty memory of the whole 'load dump'
>>situation two decades ago was that guys were flipping their alt
>>switches/breakers (which controlled the B lead contactor) while the
>>alt was under load, and killing the alt. IIRC, after multiple
>>incidents like that, the OV module/contactor circuit became a lot
>>harder to find in the AEC docs.
Yeah, your memory is correct. The Z24 pot boiled
over when I think only one individual experienced
alternator failure after cycling it. We don't know
how fast the engine was running or what the alternator
loads were . . . you never get that quality of data
from someone pointing a figure at you hollering, "you
alternator killer!"
I think Paul M was a well entrenched advisor to
that faction of RV fans and he was rather antagonistic
to anything 'crowbar'.
>My solution is the He Haw Solution: 'If it hurts when you do that,
>DON'T DO THAT!'
Exactly. If the alternator is brought off and
on line at engine idle (standard ops) then
there is no risk.
>Here's my take: If I operate the IR alternator just like it's
>operated in the car, I'll never have a load dump event. If I use an
>OV module that is relatively immune to 'false positives', along with
>a relatively robust B lead contactor, the only penalty I see is
>carrying a few ounces of extra weight for the contactor. The
>contactor will never operate unless the regulator has failed (in an
>OV mode), in which case the 'load dump' issue is already moot.
That was the spirit and intent of the design
but I failed to include a note precluding random
operations at high rpm. In all fairness, any
alternator should be able to respond safely
to on/off commands under any speed and load
conditions.
>This lets me use an off the shelf, *very inexpensive*, available at
>any auto supply, alternator. It won't be as reliable as a B&C, but
>based on anecdotal evidence from RV-x owners, a *lot* more reliable
>than a Plane Power. And I'll have about $500 left over to buy fuel.
>(Replacement alts, if ever needed, will be free.) If I do have to
>replace the alt while away from home, no mod to the alt is needed,
>and replacement can happen on the ramp with only a couple of wrenches.
Is PlanePower having issues? I think they
were bought out by a company that shall
remain nameless. Has their craftsmanship
suffered?
>I have had several different 'lives' as an electronics tech, from
>home electronics to pro sound, to industrial gear. Even though I'd
>consider myself to be well above average in qualifications, I trust
>an 'as-built' alternator to be more reliable than one that I've modded.
YEeaahh . . . with reservations. The recent
Kitplanes article we've discussed here is
a rather benign operation . . . with profound
benefit.
>My opinion is that if any update is made, it would be to redesign
>the OV module to reduce the risk of 'false positive' nuisance trips,
>and retain the B lead relay. Perhaps do a little testing on whether
>a single contact automotive cube relay can reliably open the B lead,
>*once*, as Bob Noffs mentioned, and treat the relay as if it's a fusible link.
If we combined the crowbar feature with
the 200A 'cube' relay, the ov sense could
be a microcontroller that waits until the
relay contacts are sensed to be open before
triggering the FET. That would reduce abuse
to the relay to insignificance for both
an OV shutdown -AND- the normal on/off commands
at ANY rpm.
To be sure, MOST modern alternators including
rebuilds should be able to stand off the load
dump spike.
> Realistically, if the OV module fires at ~16V, how much energy is
> really there? How much delay will there be from hitting the voltage
> threshold to the contacts opening? If we used a 100A cube relay
> (which *should*, by definition, be able to actively control a 100A
> load), will it really be stressed by 60-70 amps at ~20V? Or will
> the voltage (and energy) be much higher by the time the contacts
> actually start to open? I realize that voltage will spike upward
> as the contacts separate, but will it be bad enough in a 'one shot'
> environment to weld the contacts?
Yeah, an ov trip condition is asserted when
bus voltage rises above 16v for say 500 mS.
By this time, the energy 'spring' in the
failed alternator is really wound up pretty
good. I've observed field voltages on the
order of 1 to 2 volts for alternators carrying
a normal running load at cruise rpm. So
if you suddenly increase that voltage to 15v,
the 'spring' starts winding rapidly while held
at bay by the battery+system loads.
This is the special condition that might be
handled nicely with a fat-FET and relay.
. . . I'd want to do some studies on the
alternator test stand before running very far down
that rabbit hole.
But FOR SURE . . . a fat-FET and diode would
be a piece of cake because there's no timing
to worry about and the b-lead never rises very
far given that it's loaded down by the ship's
battery. Best yet, no concerns for keeping your
contacts out of the fire.
For an AUX alternator in the 20-30A class,
the diode/fet crowbar need not be very
beefy. Maybe not so attractive for MAIN
alternators in the 60A+ class. Voltage
drop across the diode becomes an energy
management issue.
There was a time that Cessna was using
some fat diodes in the alternator b-leads
to orchestrate an alternator failure
sensor some guy at Cessna dreamed up . . .
not me!
Here are some excerpts from a kit I wrote to
put a 100A alternator on a USAF U17. That
diode dropped about 0.9V at 100A for a
dissipation the order of 90W. Needless
to say, the heatsink was impressive. I
seem to recall we did a similar thing
on the C337. Had to dig pretty deep into
the archives for those images. Wrote that
kit in 1968!
A Schottky b-lead diode for a 30A alternator
would be much more manageable.
Bob . . .
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| Subject: | Re: OV B-lead Relay |
At 02:25 PM 4/21/2020, you wrote:
>
>One of the things I've always wondered about with Z-24 was the
>impact of the B-lead contactor opening when the field switch
>is opened. This appears to negate any positive influence of
>having a progressive switch for the master contactor and field power.
Not sure how . . . the progressive transfer is an
emulation of the 'split rocker' that simply prevents
alternator operations without a battery on line.
Adding the relay-crowbar ov control system doesn't
negate that design goal.
>What do you all think of the adjustment propose in the attached to
>Z-24 to re-introduce the goodness of the progressive switch while
>keeping the full protection offered by Z-24.
I'm not seeing the proposed advantage. Remember
that the "F" terminal on an internally regulated
alternator is simply a control lead that talks
to the internal regulator. Once the regulator
has failed, it matters not what voltage appears
at the "F" terminal . . . the b-lead is straining
to take off for the moon.
>One could also consider putting a TVS across the B-lead between the B-lead
>contactor and the alternator in an attempt to save the regulator
>if a nuisance trip of the Overvoltage protection were to take place.
Remember that TVS (transient voltage suppressor) is
designed to take on fairly large currents for a very
SHORT period of time. In Z24 the alternator cannot
be shut down hence this is no longer a transient
event but a uncontrolled runaway that will continue
until the field windings burn in two.
>P.S. did this "old school" with whiteout and a pencil, excuse the messiness...
fine pencil work . . .
Bob . . .
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| Subject: | Re: Alternator Mod to External Control |
At 02:59 AM 4/21/2020, you wrote:
>Hi Bob,
>
>Recently there has been a bit of talk re using an controlling
>internally controlled alternators. It is very easy to modify them.
>
>In Kitplanes for Nov 2019 I had published an article on how how to
>modify an alternator (Nippon Denso) with virtually no surgery; and
>it can be easily restored to standard. Doing this totally eliminates
>all the hassles with the internally regulated unit. Just use the B&C Regulator.
>
>Graeme Coates
>
>Melbourne, Australia
I've contacted Marc Cook at Kitplanes who has graciously
approved a reprint on AeroElectric.com.
Interested readers can access this nicely illustrated article at:
http://aeroelectric.com/articles/Alternators/NiponDenso_Modification_Nov_2019_Kitplanes.pdf
Bob . . .
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| Subject: | Re: OV B-lead Relay |
Bob,
Thanks for the explanation on the B-lead contactor and progressive field switch.
I like the direction you're going with the B-lead crowbar solution. Seems like
it could make the OV event much less spectacular and potentially even save a
few alternators from load dumps in nuisance trip situations. It also saves the
effort to modify the alternator to eliminate the internal regulator and keeps
the Autozone replacement alternator from taking up too much $time$.
That said, you've piqued my interest, I'll have to dig into my alternator to see
what I've got lurking inside and determine if I want to take it on. Sounds
like there was a recent Kitplanes article that outlines a simple mod, can anyone
point me to a link?
thanks,
Dan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495954#495954
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| Subject: | Re: Alternator Mod to External Control |
Thanks Bob, you read my mind!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495955#495955
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| Subject: | Re: Alternator Mod to External Control |
So I just reviewed the Kitplanes article and it got me thinking of a potentially
simpler solution. Please tell me if I'm crazy, but why not just replace the
screw in the left brush mount with a non-conductive screw and insert fiber washers
to insulate the brush mount from the B-lead. Would this then effectively
separate the field from the b-lead and make the field to the internal regulator
fully controllable using the already installed IGN connection? What am I missing?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495956#495956
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