Today's Message Index:
----------------------
1. 02:19 AM - Re: Off topic - tracing house wiring (Ron Koyich)
2. 06:11 AM - Re: Off topic - tracing house wiring (lm4@juno.com)
3. 06:14 AM - Re: Coax Cable (Robert L. Nuckolls, III)
4. 06:17 AM - Re: Re: Circuit Breakers and OVPs (Robert L. Nuckolls, III)
5. 06:19 AM - Re: Internal Regulated Alternator converted (Mark Steitle)
6. 06:23 AM - Re: Pressure altitude and short sparks (Gary Casey)
7. 06:44 AM - Re: Off topic - tracing house wiring (Eric M. Jones)
8. 07:50 AM - Re: Re: Circuit Breakers and OVPs (Wallace Enga)
9. 07:54 AM - Re: Re: Off topic - tracing house wiring (Ron Koyich)
10. 07:58 AM - Re: Pressure altitude and short sparks (Fergus Kyle)
11. 08:19 AM - Re: Re: Coax Cable (McFarland, Randy)
12. 08:25 AM - Re: Re: Off topic - tracing house wiring (Fiveonepw@aol.com)
13. 08:41 AM - Re: Re: Off topic - tracing house wiring (Richard Tasker)
14. 10:14 AM - Re: Re: Pitot Static Sources and Ram sources (Dennis Haverlah)
15. 10:27 AM - Audio Amplifier (Leo Gates)
16. 10:37 AM - Re: Re: Pressure altitude and short sparks (BobsV35B@aol.com)
17. 11:25 AM - Re: Re: Circuit Breakers and OVPs (Paul Messinger)
18. 11:53 AM - Re: Re: Pressure altitude and short sparks (Trampas)
19. 12:43 PM - Re: Re: Off topic - tracing house wiring (Eric M. Jones)
20. 12:48 PM - Re: Audio Amplifier (Eric M. Jones)
21. 01:17 PM - Re: Re: Audio Amplifier (KITFOXZ@aol.com)
22. 01:32 PM - Inrush current protection for lights (Bob Miller)
23. 02:20 PM - Re: Re: Audio Amplifier (Leo Gates)
24. 03:18 PM - Re: Inrush current protection for lights (KITFOXZ@aol.com)
25. 04:57 PM - Re: Inrush current protection for lights (klehman@albedo.net)
26. 05:53 PM - Re: Inrush current protection for lights (KITFOXZ@aol.com)
27. 09:44 PM - Alternator from Mag drive. (Patrick Elliott)
Message 1
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| Subject: | Off topic - tracing house wiring |
--> AeroElectric-List message posted by: "Ron Koyich" <Ron@Koyich.com>
Thanks, Richard - I found a transmitter/receiver pair in Sham Shui Po
today - but after getting them home and connected, I couldn't find the
other end of the cable anywhere in our flat!
God only knows where it goes - I wandered all over the place, including
many unlikely places, like the bath off the master bedroom. Nothing. No
warble tones except at the start of the cable.
Time for another approach - swagged power cords used to be in fashion
in the '70s.....
Again, thanks!
Ron
Message 2
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| Subject: | Re: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: lm4@juno.com
One name for it is "current tracker".
They are available at electrical supply houses. HTH.
Larry Mac Donald
Rochester N.Y.
do not archive
On Wed, 5 May 2004 12:57:47 +0800 "Ron Koyich" <Ron@Koyich.com> writes:
> --> AeroElectric-List message posted by: "Ron Koyich"
> <Ron@Koyich.com>
>
> Apologies for asking this on the list - but where else can one
> find
> electrical-savy people concentrated in one place?
>
> First - the home in question is in Hong Kong, and I've got no idea
> who
> installed the wiring in the first place, or if I could find them
> even if
> I knew.
>
> Here's the challenge:
>
> We have a concrete ceiling in our living room - with some 'loomex'
> type
> wire imbedded in the concrete, terminating in the middle of the
> ceiling.
>
> I've mounted a ceiling fan there, but cannot find where the other
> end of
> the wire is located. I'd assumed it was at the large bank of
> switches
> near the entrance door, as some of them did nothing. The wire
> doesn't go
> to those switches, however, so I still cannot put power to the fan.
>
> Somewhere in the dark recesses of my mind I recall seeing a device
> used
> to trace wires. One part of the unit sends some kind of pulses down
> the
> wires, and the other part is a detector for those pulses. So you
> clip
> part a) onto the cable you need to trace, and use part b) to follow
> the
> wire through whatever it's hidden behind.
>
> Do any of you know what this unit might be called - or who makes
> them
> - or where they can be purchased?
>
> Or is this another home brew project coming up?
>
>
> Thanks - Ron Koyich
>
>
>
=
>
=
>
=
> http://www.matronics.com/FAQ/AeroElectric-List.htm
>
=
>
>
>
>
>
Message 3
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--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:33 AM 5/3/2004 -0700, you wrote:
>Below is the result of your inquiry. It was submitted by
>mike speer (m.speer@shaw.ca) on Monday, May 3, 2004 at 10:33:36
>
>Monday, May 3, 2004
>
>mike speer
>
>,
>Email: m.speer@shaw.ca
>Comments/Questions: Hi..
>I have RG-58/U cable that came with my ELT, it is too short for the
>location where I want to place my antenna. I would like to know if it is
>possible to use RG-400 cable as a replacement for the supplied cable.
>Thanks for all your wonderful advise...Mike
Yes. In fact, RG400 or RG142 are the materials of choice
for modern aircraft fabrication.
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
A further benefit can be realized with membership on
the list. There are lots of technically capable folks
on the list who can offer suggestions too. You can
join at . . .
http://www.matronics.com/subscribe/
Thanks!
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 4
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| Subject: | Re: Circuit Breakers and OVPs |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 12:13 PM 5/3/2004 -0400, you wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>When an Over-Voltage Module crowbars the alternator field line to ground, it
>is extremely important to have a fast blow circuit breaker for the
>Alternator Field when using a crowbar. This fine point is easy to miss.
Define "fast blow circuit breaker" . . .
The fault current that flows in the crowbar module is
something on the order of 200-300A when it trips. I'm aware
of no 5A breaker that is particularly "slow" when
presented with this condition. I can offer no
valid "concerns" to anyone who is selecting breakers for
their project where the use of crowbar ov protection is
anticipated.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 5
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| Subject: | Re: Internal Regulated Alternator converted |
to External?
--> AeroElectric-List message posted by: Mark Steitle <msteitle@mail.utexas.edu>
Bobby,
A while back I wrote up an explanation for some on this list on how to
convert the ND internally-regulated alternator to external regulation. I
don't see where it would matter which external regulator you use, as long
as the voltage is correct. A search of the archives should locate the
article.
Mark S.
At 11:01 PM 5/4/2004 -0500, you wrote:
>--> AeroElectric-List message posted by: Bobby Hester
><bhester@hopkinsville.net>
>
>Has anyone had there Van's internal regulated 60amp alternator converted
>to external and used B&C's LR3C-14 regulator?
>Does this make since to do?
>
>--
>Surfing the Web from Hopkinsville, KY
>Visit my web site at: http://www.geocities.com/hester-hoptown/RVSite/
>RV7A Slowbuild wings-QB Fuse :-)
>
>
Message 6
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| Subject: | Re: Pressure altitude and short sparks |
--> AeroElectric-List message posted by: "Gary Casey" <glcasey@adelphia.net>
<<But as I recall, the ideal gas law states, PV = nRT. If the compression
ratio is 10:1 and you have isothermal compression then the final
pressure will indeed be 10x the inlet pressure as P varies inversely with
V since n, R, and T don't change. I know that this is not totally realistic
but delta-T is going to be a lot smaller than you think because the heat of
compression
will quickly transfer to the head and piston crown.>>
You are right in the gas law, but the assumption of constant temperature
(isothermal) compression is incorrect. It is very close to adiabatic (no
heat transfer) than it is to isothermal. In that case V has an exponent
that turns out to be approximately 1.4. Since there is actually some heat
transfer the exponent can be assumed to be a little lower than 1.4, so 1.35
might be a better number - the higher the engine speed the closer it is to
adiabatic. You're right, it does sound a little picky except that going
from isothermal to adiabatic changes the predicted peak pressure from 10X to
24X - it can't be ignored.
Another post said:
<<Thus the engine will run perfect
at low altitudes and miss or cross fire under a load at high altitudes.>>
Exactly, but only true for turbocharged engines that can maintain a fixed
manifold pressure regardless of altitude. For a naturally aspirated engine
the compression pressure drops in proportion to atmospheric pressure so
there is no more cross-firing problem at altitude than at sea level.
Also:
<<Thus automotive manufactures have started going to coil on plug. That is
there is one coil
per plug. This means they can put more energy into the spark plug and
increase the spark plug gap, thus making it more likely you can ignite the
fuel, getting fast combustion propagation and also run a leaner mixture, one
closer to 14.7:1, and some times even leaner.>>
Typical Coil-On-Plug (COP) systems use coils that actually require SHORTER
dwell times that single-coil systems. The reason for this is that with no
losses in the plug wires it takes less spark energy to light the fire. A
byproduct of that is the voltage rise times are faster, making it more
likely that fouled plugs will still fire. But the reason for using COP
ignition is mainly to eliminate the least reliable part of the engine - the
plug wires (Then why does GM mount the individual coils on the valve cover
and use short plug wires? Have to ask them). And, yes, a leaner mixture
has a higher dielectric strength than a rich one, requiring higher spark
voltages. Automotive engines run 99% of the time at exactly 14.7:1 air/fuel
ratio so the push to higher voltages has pretty much stopped. An aircraft
engine at peak EGT is running about 15:1 and at 100 LOP is at about 16:1,
leaner than an automotive engine mixture.
Gary Casey
Message 7
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| Subject: | RE: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>From: Ron Koyich (Ron@Koyich.com)
Now hold on there Roy! Don't give up. The Aeroelectric list has a combined
IQ greater than all of China, even with Bob N on vacation. So here's my
suggestion.
The tester you have may be the wrong tool. Is it one where you attach leads
to wires and then go look for them in a fusebox? Then it won't do this job.
We need to know: Since apparently you have access to the ceiling leads only;
can you determine anything from them? Are there two leads or three? Are they
grounded to each other or ground? Is there resistance from one to the other?
Have you opened all fixtures, switches and outlets for inspection? Anything
else?
Possible approaches:
1) Metal detector. Depending on the construction of the house, might work
well.
2) Signal generator/radio method: Attach the output of the signal generator
tuned to a radio station frequency to the ceiling wires (assuming they're
not live). Use an AM radio tuned to the same frequency. When near the wire,
the radio station will be blocked. Some fiddling around may be required.
This works well to eliminate annoying radio and TV stations from the local
area as well.
3) Call an electrician.
4) Call a better electrician.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
Message 8
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| Subject: | Re: Circuit Breakers and OVPs |
--> AeroElectric-List message posted by: Wallace Enga <wenga@svtv.com>
Bob,
On a related subject, do you have a part # / source for a device to handle
the Load Dump issue and Internal Voltage Regulators that was discussed
here a couple of months ago?
Thanks
Wally Enga
At 08:15 AM 5/5/04 -0500, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 12:13 PM 5/3/2004 -0400, you wrote:
> >--> AeroElectric-List message posted by: "Eric M. Jones"
> <emjones@charter.net>
> >
> >When an Over-Voltage Module crowbars the alternator field line to ground, it
> >is extremely important to have a fast blow circuit breaker for the
> >Alternator Field when using a crowbar. This fine point is easy to miss.
>
> Define "fast blow circuit breaker" . . .
>
> The fault current that flows in the crowbar module is
> something on the order of 200-300A when it trips. I'm aware
> of no 5A breaker that is particularly "slow" when
> presented with this condition. I can offer no
> valid "concerns" to anyone who is selecting breakers for
> their project where the use of crowbar ov protection is
> anticipated.
>
> Bob . . .
Message 9
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| Subject: | RE: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: "Ron Koyich" <Ron@Koyich.com>
Thanks, Eric - on the one hand you give me confidence that we might get
somewhere, then on the other you get my name wrong - ah, lack of
confidence creeping in.
My name is Ron - not Roy. You're not the first to make this mistake -
I think it has to do with the 'Koy' in my family name.
>>We need to know: Since apparently you have access to the ceiling leads
only; can you determine anything from them?<<
>> Are there two leads or three?<<
Three leeds. None connected to anything. No voltage and infinite
resistance between any two.
>> Are they grounded to each other or ground? <<
No - total open circuit - the other end is floating somewhere.
>>Is there resistance from one to the other?<<
No.
>>Have you opened all fixtures, switches and outlets for inspection?<<
Not absolutely every one, Eric. But nearly every one and all close by.
And I've put a warble tone on the leads and found the other ends of the
wires nowhere, including searching in every room of the apartment, and
all wiring fixtures.
>> Anything else?<<
The wires may terminate in the flat above us.<g>
>>Call an electrician<<
My bet is he'd want to chisel out the ceiling and run a cable over to the
wall - too much mess. Decorating department has ruled out swag cord to
the fan.
If you're in the neighbourhood, Eric, please drop by and sort it out for
us....
Thanks for the suggestions - we're into deep thinking now.<g>
Best - Ron
Message 10
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| Subject: | Re: Pressure altitude and short sparks |
--> AeroElectric-List message posted by: "Fergus Kyle" <VE3LVO@rac.ca>
Cheers,
I had no idea what I stirred up with this topic, but found the
byplay very interesting and have archived some extensive text on same. Added
some depth to a shallow understanding of how an engine pumps out its
guts............
Thanks for the trouble taken!
Ferg
Europa A064
Message 11
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--> AeroElectric-List message posted by: "McFarland, Randy" <Randy.McFarland@novellus.com>
Along the lines of RG 400 use, can anyone tell me why the Garmin 327
Transponder installation manual suggests in their Antenna Cable table 2-1
the max length for the cable is 8.8 feet if using RG 400?
Is this length specific to the transponder antenna only? Can I run RG 400
for Com / Nav antennas longer than 8.8 feet? (like about 20' out to the
wingtip?)
Thx
Randy
RV7A Panel wiring
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:bob.nuckolls@cox.net]
Subject: AeroElectric-List: Re: Coax Cable
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 10:33 AM 5/3/2004 -0700, you wrote:
>Below is the result of your inquiry. It was submitted by
>mike speer (m.speer@shaw.ca) on Monday, May 3, 2004 at 10:33:36
>
>Monday, May 3, 2004
>
>mike speer
>
>,
>Email: m.speer@shaw.ca
>Comments/Questions: Hi..
>I have RG-58/U cable that came with my ELT, it is too short for the
>location where I want to place my antenna. I would like to know if it is
>possible to use RG-400 cable as a replacement for the supplied cable.
>Thanks for all your wonderful advise...Mike
Yes. In fact, RG400 or RG142 are the materials of choice
for modern aircraft fabrication.
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
A further benefit can be realized with membership on
the list. There are lots of technically capable folks
on the list who can offer suggestions too. You can
join at . . .
http://www.matronics.com/subscribe/
Thanks!
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 12
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| Subject: | Re: RE: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: Fiveonepw@aol.com
In a message dated 5/5/04 9:55:26 AM Central Daylight Time, Ron@Koyich.com
writes:
> Thanks for the suggestions - we're into deep thinking now.<g>
>
>
> Best - Ron
>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Hey Rob (KIDDING!) Make that RON-
Are these wires in conduit? It would be odd if they are just buried in the
concrete, but local building codes/traditions might allow that-
If in conduit, maybe you could try:
1- Tape a boom box speaker up to the hole, turn it up loud and see if the
music escapes elsewhere
2- Attach a vacuum cleaner hose (the BLOW side) tightly to the wire exit,
restrict the flow at the SUCK inlet and place a smoke bomb located so smoke
enters the vacuum- look for smoke elsewhere, dont forget the breaker/fuse panel
(and might best avoid using smoke from controlled substances.......)
3- If smoke is unacceptable, try week-old unrefrigerated fish and give it the
ol' "sniff" test.
4- Perhaps these are connected to a video camera- connect a monitor and maybe
you can SEE where the wires go!
WARNING- none of the above may contribute to upstairs neighbor appreciation
if in fact wiring does go there! 8-) (Well, they might like your choice
of music or maybe not....)
Mark - do not archive
Message 13
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| Subject: | Re: RE: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: Richard Tasker <retasker@optonline.net>
Ron, we lived in HK for three years and I know what you are going
through. We had a similar problem when wires running to an outlet that
our heater/air conditioner was connected to burned out (thank goodness
for concrete or we may have had more than just burned out wiring). One
would have thought that it would have been an easy job to just pull new
wires through the embedded conduit... Unfortunately, the conduit had
evidently corroded and the old wires were trapped in the conduit. I
finally ended up just running surface wiring to the outlet. The joys of
HK construction! The fuse box was such a nightmare I didn't even want
to open the door!
If you haven't already tried, connect the wire tracer to a known set of
wires to make sure that it is working and will actually trace wires like
you want to do. Most of the tracers available in the US assume that you
have typical US wiring - no conduit, no armored cable - so they may not
work in HK where the wiring is installed in conduit embedded in concrete
with lots of rebar around (and who knows - they may have embedded the
wiring directly.
And, yes, I am sure that an electrician would do exactly what you
suggest - lots of chiseling and lots of dust...
Dick Tasker
>
>
Message 14
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| Subject: | Re: Pitot Static Sources and Ram sources |
--> AeroElectric-List message posted by: Dennis Haverlah <clouduster@austin.rr.com>
To keep bugs out of my pitot tube and fuel tank vent tubes on my
Bonanza, I crumpled up a small piece of aluminum screen and pushed it
into each tube. Keep it within 1/16 to 1/8 inch of the end. No more
bugs and the air can move in or out OK. Has worked for over 10 years.
Dennis H.
Eric M. Jones wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>It would make a great science project for your high school student to
>determine if there is a size tube that is unattractive to mud wasps (and
>therefore best for pitot [after Henri Pitot (1695-1771), French physicist]
>tubes).
>
>For bees, it turns out that if a gap (and maybe a hole) is below a certain
>size, the bee will fill it. If the gap is bigger, the bees will build comb
>in it, but if it is a certain size (7.5mm +/-1.5 mm) the bees will simply
>ignore it. Rev. Lorenzo Langstroth (Philadelphia in 1851) was the first
>person to use the bee space in hive construction. How he determined that
>bees used the metric system is truly one of the wonders of science.
>
>You don't have to search the NTSB very hard to find "wasp-like creature in
>pitot tube" accidents. And you don't have to talk to many pilots to find
>hair-raising tales that thankfully didn't end up in an NTSB report. Usually
>pitot tube clogs are discovered near flying speed, half-way down the runway.
>
>For static sources I am convinced (perhaps incorrectly) that too much fuss
>is made of their position. And yes, you can tee off many instruments to the
>same static source, and have multiple static sources. Classically static
>sources have been taken from the supports for or just behind pitot ram
>sources.
>
>For pitot ram sources, you can also tee off many instruments, and
>furthermore you can have multiple ram sources (several pitot tubes) leading
>into one line. This seems never to have been done in EAA aircraft. Big
>planes often use two or more pitot tubes but route them to their own
>instrument banks.
>
>I am designing a spare retractable pitot tube. The prototype will appear on
>my website shortly. Comments are solicited.
>
>Regards,
>Eric M. Jones
>www.PerihelionDesign.com
>113 Brentwood Drive
>Southbridge MA 01550-2705
>Phone (508) 764-2072
>Email: emjones@charter.net
>
>Ring the bells that still can ring
>Forget your perfect offering
>There is a crack in everything
>That's how the light gets in
> - - Leonard Cohen
>
>
>
>
Message 15
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--> AeroElectric-List message posted by: Leo Gates <leogates@allvantage.com>
I would like to build an audio amplifier for my Zenith CH601HDS. I want
to mount a 3 way bookshelf speaker in the baggage compartment and feed
the headset audio to it. The speaker I have will handle 40 watts but I
think driving it with 10 -20 watts should be adequate - any thoughts?
The amplifier needs 150 Ohm input and 4 - 8 Ohm output, 12 V. DC power.
Anyone know of a source, either diagram or ready made?
Leo Gates
Message 16
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| Subject: | Re: Pressure altitude and short sparks |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 5/5/04 8:24:05 AM Central Daylight Time,
glcasey@adelphia.net writes:
Exactly, but only true for turbocharged engines that can maintain a fixed
manifold pressure regardless of altitude. For a naturally aspirated engine
the compression pressure drops in proportion to atmospheric pressure so
there is no more cross-firing problem at altitude than at sea level.
Also:
Good Afternoon Gary,
That may be the theory, but I have flown several Jacobs powered
aircraft that always misfired above ten or twelve thousand feet
and smoothed out nicely down low. When new wires were pulled
into the ignition loom, the high altitude problems ceased.
I have no way of knowing for sure what was happening, but it
sure acted like it was cross-firing and the new harness did solve
the problem.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Do Not Archive
Message 17
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| Subject: | Re: Circuit Breakers and OVPs |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
I am one of two that are doing an engineering test characterization and
design of a Load dump clamp.
I am sorry but that project is way behind but nearing completion of
preliminary results. There are other pressing issues (not related to load
dump) that is delaying my completing the testing.
I (we) fully expect to have one or two proven solutions available as well as
purchase info, now estimated late this month.
Paul
----- Original Message -----
From: "Wallace Enga" <wenga@svtv.com>
Subject: Re: AeroElectric-List: Re: Circuit Breakers and OVPs
> --> AeroElectric-List message posted by: Wallace Enga <wenga@svtv.com>
>
> Bob,
>
> On a related subject, do you have a part # / source for a device to handle
> the Load Dump issue and Internal Voltage Regulators that was discussed
> here a couple of months ago?
>
> Thanks
> Wally Enga
>
> At 08:15 AM 5/5/04 -0500, you wrote:
> >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> ><bob.nuckolls@cox.net>
> >
> >At 12:13 PM 5/3/2004 -0400, you wrote:
> > >--> AeroElectric-List message posted by: "Eric M. Jones"
> > <emjones@charter.net>
> > >
> > >When an Over-Voltage Module crowbars the alternator field line to
ground, it
> > >is extremely important to have a fast blow circuit breaker for the
> > >Alternator Field when using a crowbar. This fine point is easy to miss.
> >
> > Define "fast blow circuit breaker" . . .
> >
> > The fault current that flows in the crowbar module is
> > something on the order of 200-300A when it trips. I'm aware
> > of no 5A breaker that is particularly "slow" when
> > presented with this condition. I can offer no
> > valid "concerns" to anyone who is selecting breakers for
> > their project where the use of crowbar ov protection is
> > anticipated.
> >
> > Bob . . .
>
>
Message 18
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| Subject: | Re: Pressure altitude and short sparks |
--> AeroElectric-List message posted by: "Trampas" <tstern@nc.rr.com>
Gary,
<<Exactly, but only true for turbocharged engines that can maintain a fixed
manifold pressure regardless of altitude. For a naturally aspirated engine
the compression pressure drops in proportion to atmospheric pressure so
there is no more cross-firing problem at altitude than at sea level.
Actually there is, if the atmospheric pressure drops then it is easier for
the spark to jump to neighboring tab in distributor cap. It really has
little to do with the compression pressure other than the plug on the
compression stroke requires high voltage to fire and when this voltage is
higher than the voltage required to jump to neighboring tab on distributor
cap, electricity will flow via path with least resistance.
Trampas
Message 19
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| Subject: | RE: RE: Off topic - tracing house wiring |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: "Ron Koyich" <Ron@Koyich.com>
Sorry about the name thing Ron.
Many good suggestions have bubbled up to the surface. I especially like the
smoke thing or the vacuum cleaner thing, if there is a conduit. Carbon
dioxide would work well too. On a humid day, CO2 would cause condensation on
the concrete where the conduit is.
Or if you can establish that the conduit or wiring is not too deep, boring
test holes with a diamond hole saw would access the wiring, not make much
mess, and could easily be patched.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
"Mankind faces a cross-roads.
One path leads to despair and utter hopelessness.
The other, to total extinction.
Let us pray we have the wisdom to choose correctly."
--Woody Allen
Message 20
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| Subject: | Re: Audio Amplifier |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>From: Leo Gates (leogates@allvantage.com)
http://www.allelectronics.com/cgi-bin/category.cgi?category=937&item=AMP-30&type=store
Eric M. Jones
(do not archive)
Message 21
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| Subject: | Re: Audio Amplifier |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
In a message dated 5/5/2004 3:50:18 PM Eastern Standard Time,
emjones@charter.net writes:
http://www.allelectronics.com/cgi-bin/category.cgi?category=937&item=AMP-30&ty
pe=store
Eric M. Jones
Eric, Leo,
This amp calls for an AC power input not DC. But, not to worry, you may be
able to bypass internal power supply rectifier and run on DC.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
Message 22
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| Subject: | Inrush current protection for lights |
--> AeroElectric-List message posted by: "Bob Miller" <drmiller@cvillepsychology.net>
I've seen little button-size devices that you insert between a standard lightbulb
and its socket that supposedly reduces the shock of inrush current that tends
to wear out filaments. A keepwarm circuit would be preferable, but my PM
alternator produces only 10 amps continuous and I'm about at that limit. Is
there anything like those button devices that might work in an aircraft as an
alternative to a keepwarm circuit? I know it won't protect the lamps from vibration
damage, but it would at least be better than nothing.
Bob Miller
Message 23
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| Subject: | Re: Audio Amplifier |
--> AeroElectric-List message posted by: Leo Gates <leogates@allvantage.com>
Eric, John,
My thoughts exactly. I ordered one today.
Thanks again Eric and thanks John.
Leo
KITFOXZ@aol.com wrote:
>--> AeroElectric-List message posted by: KITFOXZ@aol.com
>
>In a message dated 5/5/2004 3:50:18 PM Eastern Standard Time,
>emjones@charter.net writes:
>http://www.allelectronics.com/cgi-bin/category.cgi?category=937&item=AMP-30&ty
>pe=store
>
>Eric M. Jones
>
>Eric, Leo,
>
>This amp calls for an AC power input not DC. But, not to worry, you may be
>able to bypass internal power supply rectifier and run on DC.
>
>John P. Marzluf
>Columbus, Ohio
>Kitfox Outback (out back in the garage)
>
>
>
>
Message 24
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| Subject: | Re: Inrush current protection for lights |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
In a message dated 5/5/2004 4:34:23 PM Eastern Standard Time,
drmiller@cvillepsychology.net writes:
I've seen little button-size devices that you insert between a standard
lightbulb and its socket that supposedly reduces the shock of inrush current that
tends to wear out filaments. A keepwarm circuit would be preferable, but my PM
alternator produces only 10 amps continuous and I'm about at that limit.
Is there anything like those button devices that might work in an aircraft as
an alternative to a keepwarm circuit? I know it won't protect the lamps from
vibration damage, but it would at least be better than nothing.
Bob Miller
Bob,
The device you have seen I believe is simply a diode that rectifies the
voltage supply to a household light bulb. Instead of the bulb's filament dropping
the entire 120 volt AC voltage across itself, it only sees a half wave pulsing
DC supply at half average voltage. The bulb will last a long time but with
less light output. For DC voltage aircraft application I would guess using the
lowest wattage bulb that will give the minimum light that you require is
best. Keep it cooled and vibration protected and forget about browning out the
applied voltage. Why waste power on a filament protection device when you only
have 10 amps in the bank?
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
Message 25
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| Subject: | Re: Inrush current protection for lights |
--> AeroElectric-List message posted by: klehman@albedo.net
Keystone also makes a variety of inrush limiters which are just
thermistors that have a high cold resistance and less resistance when
they heat up. Physically they look like an MOV or a large ceramic disc
capacitor. I have tried them on sealed beam lamps and they seem to only
dim the lamp very slightly. Personally I think it is not worth the
effort for automotive style lamps but it might be worth it for more
expensive certified lamps.
Ken
KITFOXZ@aol.com wrote:
> --> AeroElectric-List message posted by: KITFOXZ@aol.com
>
> In a message dated 5/5/2004 4:34:23 PM Eastern Standard Time,
> drmiller@cvillepsychology.net writes:
> I've seen little button-size devices that you insert between a standard
> lightbulb and its socket that supposedly reduces the shock of inrush current
that
> tends to wear out filaments. A keepwarm circuit would be preferable, but my
PM
> alternator produces only 10 amps continuous and I'm about at that limit.
> Is there anything like those button devices that might work in an aircraft as
> an alternative to a keepwarm circuit? I know it won't protect the lamps from
> vibration damage, but it would at least be better than nothing.
>
> Bob Miller
>
> Bob,
>
> The device you have seen I believe is simply a diode that rectifies the
> voltage supply to a household light bulb. Instead of the bulb's filament dropping
> the entire 120 volt AC voltage across itself, it only sees a half wave pulsing
> DC supply at half average voltage. The bulb will last a long time but with
> less light output. For DC voltage aircraft application I would guess using the
> lowest wattage bulb that will give the minimum light that you require is
> best. Keep it cooled and vibration protected and forget about browning out the
> applied voltage. Why waste power on a filament protection device when you only
> have 10 amps in the bank?
>
> John P. Marzluf
> Columbus, Ohio
> Kitfox Outback (out back in the garage)
Message 26
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| Subject: | Re: Inrush current protection for lights |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
In a message dated 5/5/2004 7:59:28 PM Eastern Standard Time,
klehman@albedo.net writes:
Keystone also makes a variety of inrush limiters which are just
thermistors that have a high cold resistance and less resistance when
they heat up. Physically they look like an MOV or a large ceramic disc
capacitor. I have tried them on sealed beam lamps and they seem to only
dim the lamp very slightly. Personally I think it is not worth the
effort for automotive style lamps but it might be worth it for more
expensive certified lamps.
Ken
Hello Ken,
There are so many variations to semiconductor devices it is hard to tell
exactly what it is without a data sheet. There used to be a device used in
television circuits called a VDR (voltage dependent resistor) that looked like
an
MOV in a black or dark brown disk packaging. They may still be used, I don't
know. Upon initial power up the device offers very low resistance in series
with the degaussing coil, once full voltage is realized across the coil, the
resistance climbs to near infinity, shutting off the current to the coil. Perhaps
they are actually temperature transient activated?
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
Message 27
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| Subject: | Alternator from Mag drive. |
--> AeroElectric-List message posted by: "Patrick Elliott" <pelliott@innercite.com>
Just bought a VariEze and need a power source. I'm putting two LSE Plasma 3
systems on it and will have two empty mag holes. Does anyone know of a
light weight alternator that is driven from a magneto drive? before you
ask .. It's on a Rotorway Rw-100 which uses standard Slick mags. same mags
you'd find on an O-200
_____
Patrick Elliott
541 297 0004
---
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