Today's Message Index:
----------------------
1. 02:51 AM - Re: How do you carry the braid from a shielded... (Jay Brinkmeyer)
2. 05:52 AM - Re: LED Bias Resistors (John Schroeder)
3. 06:56 AM - Dual Alternators (Jim Butcher)
4. 07:04 AM - Re: Stereo vs. Mono Headphone Jacks (Bordelon, Greg)
5. 07:19 AM - Battery Buss (Speedy11@aol.com)
6. 07:52 AM - Re: Battery Buss (Robert L. Nuckolls, III)
7. 07:53 AM - Re: Re: How do you carry the braid from a (Robert L. Nuckolls, III)
8. 07:56 AM - Alternator light misteries (Hans Teijgeler)
9. 08:45 AM - Re: LED Bias Resistors (John Schroeder)
10. 09:21 AM - Re: Re: How do you carry the braid from a shielded... (Bob C.)
11. 09:29 AM - Aerospace Logic instruments (Ken Simmons)
12. 09:55 AM - Re: Aerospace Logic instruments (rv-9a-online)
13. 12:10 PM - Re: Dual Alternators (James H Nelson)
14. 12:40 PM - Re: Heated Pitot Tube Installations - New article (Robert L. Nuckolls, III)
15. 12:42 PM - Re: Relays for heated pitot tube circuit (Robert L. Nuckolls, III)
16. 01:23 PM - Re: Aerospace Logic instruments (Robert L. Nuckolls, III)
17. 01:54 PM - Re: Aerospace Logic instruments (Ken Simmons)
18. 03:36 PM - Re: Relays for heated pitot tube circuit ()
19. 05:01 PM - Re: Battery Buss (Jim Stone)
20. 08:53 PM - Re: Stereo vs. Mono Headphone Jacks (Kingsley Hurst)
21. 09:10 PM - Re: LED Bias Resistors (Robert L. Nuckolls, III)
22. 09:16 PM - Re: Alternator light misteries (Robert L. Nuckolls, III)
23. 09:18 PM - Re: Dual Alternators (Robert L. Nuckolls, III)
24. 09:30 PM - Re: Relays for heated pitot tube (Robert L. Nuckolls, III)
25. 09:35 PM - Re: Stereo vs. Mono Headphone Jacks (Robert L. Nuckolls, III)
26. 09:37 PM - Re: Size of Fuse vs. Circuit Breaker (Robert L. Nuckolls, III)
27. 09:42 PM - Com antenna relay?? (Robert L. Nuckolls, III)
28. 10:15 PM - Re: Stereo vs. Mono Headphone Jacks (Kingsley Hurst)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: How do you carry the braid from a shielded... |
--> AeroElectric-List message posted by: Jay Brinkmeyer <jaybrinkmeyer@yahoo.com>
Back to my original question... Am I asking for trouble by running my
Whelan-type strobe wires through a mil spec molex connect at the wing root? If
so, then what sort of connector might be used? If none, then I get to buy more
wire and terminate only at the power supply...
Thanks,
Jay
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<b.nuckolls@cox.net>
shielded
<snip>
Case in point . . . the wires running from strobe power supplies
are twisted trios with all outbound electrons matched by inbound
electrons. I'll bet that the shielding of that wire offers no
demonstrable benefits other than insurance against an invasion
of pink elephants . . . but yes, there is a sharp rise time
trigger pulse of 300 volts or more that runs out that wire . . .
having a shield is not a bad idea but it's certainly not going
to stand or fall on the length of a pigtail that carries it
through a connector.
<snip>
=====
__________________________________
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: LED Bias Resistors |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
Dick Trasker & Matt Prather
Your last responses answered it all for me. Many thanks again for the help.
Cheers,
John
Do not archive
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Dual Alternators |
--> AeroElectric-List message posted by: "Jim Butcher" <europa@triton.net>
I am fitting a second alternator to a Rotax 914. It is a B&C L60 driven off
the crank shaft so will generate about 40A at 5000 RPM. The circuit I'm
using is Z-13. Is there a problem in having both alternators "turned on" at
the same time, ie DC Power Master Switch ON to operate the L60 and the Aux
Alt ON to operate the S704-1 relay? Seems like some have said the Rotax
(Ducatti) regulator will not tolerate this.
Thanks
Jim Butcher Europa A185 N241BW
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Stereo vs. Mono Headphone Jacks |
--> AeroElectric-List message posted by: "Bordelon, Greg" <gbordelon@hess.com>
Dennis,
I am in the mist if a panel redo.....and I am going to install a small
slide or toggle switch next to the headset jacks to allow me to switch
from stereo to mono when needed. If you wire it stereo only, when you
plug in a mono headset you'll only hear the audio in one ear. With a
switch you could rectify that.....
Greg
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Dennis Johnson
Subject: AeroElectric-List: Stereo vs. Mono Headphone Jacks
--> AeroElectric-List message posted by: "Dennis Johnson"
--> <pinetownd@volcano.net>
Greetings,
I'm starting the electrical planning for my Lancair Legacy and wonder
about the advantages and disadvantages of stereo vs. mono headphone
jacks. At this point, I don't see any need for stereo headphones, but
if there aren't any significant disadvantages, I wonder if it would be
wise to wire for stereo in case my plans change in the future. What
happens if I plug mono headphones into a stereo jack and vice versa? Any
other thoughts?
Thanks,
Dennis Johnson
Lancair Legacy
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: Speedy11@aol.com
Listers,
Please correct me if I'm wrong. The way I see it, the only reason I need a
battery buss is to provide always available power for things such as engine
ignition, clock, or small courtesy lights. If I don't have any of those things,
then I could do without a battery buss.
Stan Sutterfield
Tampa
www.rv-8a.net
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Battery Buss |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 10:18 AM 2/15/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: Speedy11@aol.com
>
>Listers,
>Please correct me if I'm wrong. The way I see it, the only reason I need a
>battery buss is to provide always available power for things such as engine
>ignition, clock, or small courtesy lights. If I don't have any of those
>things,
>then I could do without a battery buss.
Correct.
Technically, the single always hot feed from battery to the
e-bus alternate feed switch is a "battery bus" connection
but it can be much simpler than a fuseblock with multiple
taps.
Bob . . .
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: How do you carry the braid from a |
shielded...
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
shielded...
At 02:47 AM 2/15/2005 -0800, you wrote:
>--> AeroElectric-List message posted by: Jay Brinkmeyer
><jaybrinkmeyer@yahoo.com>
>
>Back to my original question... Am I asking for trouble by running my
>Whelan-type strobe wires through a mil spec molex connect at the wing root? If
>so, then what sort of connector might be used? If none, then I get to buy more
>wire and terminate only at the power supply...
carrying shield connections through connectors on separate
pins is a time honored technique well founded both in physics
and practice throughout the aviation industry and many others.
Bob . . .
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Alternator light misteries |
--> AeroElectric-List message posted by: "Hans Teijgeler" <hans@jodel.com>
Hi guys,
I am wiring up a dual battery, single alternator setup using an internally
regulated ND alternator (55 amp) for a dual computer, dual fuel pump Subaru
engine.
My system will be somewhat simpler than Z-14 (which has dual batteries, dual
alternators and a crossfeed function). Basically this:
* Battery A feeds engine bus A
* Battery B feeds engine bus B
* Battery A feeds main power bus (strictly VFR, no electric flaps, trim or
anything, so all of this electricity is a luxury item and not strictly
needed, hence no attempt to connect to battery B in case number A fails.
Tough luck for ATC)
* Battery B feeds starter (I could use two starter solenoids and a toggle
switch to enable battery B starting as well, but these solenoids are HEAVY).
Now, normal starting will be with engine on battery A and starter on B. If I
run down battery A, I can switch to battery and engine bus B, and still use
the starter.
* Alternator feeds both batteries through a 70 amp diode to each battery.
No problems so far (unless you think that I've got this design all wrong),
until I got to the point of wiring up the alternator light. This one is
supposed to go to +12V. But which one? The alternator is feeding both
systems, so I guess either battery A or B would do?
Can someone elaborate on what the true function of this light really is?
What is it telling me? What if the light bulb breaks, will that affect
alternator operation? Could I wire in a diode-resistor combo, or does it
need to be a light bulb? Do I really need this light, or would a negative
amps alarm on my ammeter(s) make more sense?
Thanks!
Hans
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: LED Bias Resistors |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
Robert L. Nuckolls, III <b.nuckolls@cox.net> wrote:
> A pair of 220 ohm resistors wired as suggested provides about 35 mA of
> drive to an LED when the LR-3 is flashing the lamp. 220 was picked
> because it's a commonly stocked value
Bob -
My problem is that 35 milliamps of current, when the LR-3 provides the
signal, will put 1.75 times the amount of current specified by the NKK LED
lamps we are using. I came up with 560 because that gives me a tolerable
bit of overdrive and I can get the resistors at Radio Shack. That is the
basis of my original question.
Thanks,
John
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: How do you carry the braid from a shielded... |
--> AeroElectric-List message posted by: "Bob C. " <flyboy.bob@gmail.com>
Now that's the kind of answer I like . . . wasn't that the original question?!
On Tue, 15 Feb 2005 09:52:38 -0600, Robert L. Nuckolls, III
<b.nuckolls@cox.net> wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
shielded...
>
> At 02:47 AM 2/15/2005 -0800, you wrote:
>
> >--> AeroElectric-List message posted by: Jay Brinkmeyer
> ><jaybrinkmeyer@yahoo.com>
> >
> >Back to my original question... Am I asking for trouble by running my
> >Whelan-type strobe wires through a mil spec molex connect at the wing root?
If
> >so, then what sort of connector might be used? If none, then I get to buy more
> >wire and terminate only at the power supply...
>
> carrying shield connections through connectors on separate
> pins is a time honored technique well founded both in physics
> and practice throughout the aviation industry and many others.
>
> Bob . . .
>
>
>
>
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Aerospace Logic instruments |
--> AeroElectric-List message posted by: "Ken Simmons" <ken@truckstop.com>
I'm thinking/planning on installing a couple of the digital instruments from Aerospace
Logic to replace some analog Mitchell instruments. The manuals for the
digital instruments state they are internally fused and that an external fuse/breaker
is not necessary, just tie them to the battery buss.
Is this an OK/wise thing to do? I think I would feel more comfortable with at least
a common fuse/breaker protecting the set.
Thanks.
Ken
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Aerospace Logic instruments |
--> AeroElectric-List message posted by: rv-9a-online <rv-9a-online@telus.net>
Ken, the purpose of the fuses in the aircraft are to protect the wiring,
not the instruments. If you follow their advice, and you had a wiring
short, you could have a combustion event... and the instrument fuse
would never blow.
Conversely, external fuses are not there to protect the instrument.
Instruments should have their own internal protection, if required.
Vern Little
RV-9A
http://www3.telus.net/aviation/flying/RV-9A/rv-9a.html
http://www3.telus.net/aviation/vx.html
Ken Simmons wrote:
>--> AeroElectric-List message posted by: "Ken Simmons" <ken@truckstop.com>
>
>I'm thinking/planning on installing a couple of the digital instruments from Aerospace
Logic to replace some analog Mitchell instruments. The manuals for the
digital instruments state they are internally fused and that an external fuse/breaker
is not necessary, just tie them to the battery buss.
>
>Is this an OK/wise thing to do? I think I would feel more comfortable with at
least a common fuse/breaker protecting the set.
>
>Thanks.
>Ken
>
>
>
>
>
>
>
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Dual Alternators |
--> AeroElectric-List message posted by: James H Nelson <rv9jim@juno.com>
Jim,
Use a seperate regulator for the 40A alternator and leave the
Duccati for the Rotax unit. I used the B&C regulator for the 40A unit.
Jim Nelson
N15JN (sold)
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Heated Pitot Tube Installations - New article |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
Mike,
Thank you for sharing this. Yes, your data tracks nicely with that
which I've gathered on a variety of tubes over the years. I dug
through the pile of data I have and crafted an article which I've
posted at:
http://aeroelectric.com/articles/Pitot_Heater/Gauging_Pitot_Heater_Performance.pdf
I think this piece will illuminate the decision making processes
for installing heated pitot tubes in airplanes.
Bob . . .
At 06:27 PM 2/12/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: Mike Nellis <mike@bmnellis.com>
>
>Bob,
>
>A few years ago I tested the 5814 pitot/static tube which is basically
>the same as the one you have. You can see the graphed results here
>http://www.bmnellis.com/pitotcurrent.htm along with raw data link in the
>middle of the page.
>
>--
>Mike Nellis
Message 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
vs. Circuit Breaker - Corrected
| Subject: | Re: Relays for heated pitot tube circuit |
question was Size of Fuse vs. Circuit Breaker - Corrected
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
question was Size of Fuse vs. Circuit Breaker - Corrected
>
>Bob,
> I have a Piper style heated 12 volt pitot. This unit has 2 heating
> elements. Each element draws 5 amps and has 16 AWG leads to each element.
> I would like to a 2-2 style switch to control the heater. Each heater
> element would have it's own fused circuit running 16AWG wire.
> Your previous advice has been that relays are not needed to protect the
> switch when current draw does not exceed 5 amps. Since this double pole
> switch will limit warmed up current to 5 amps per set of contacts in the
> switch, will this be sufficient? Will the high "in rush" current
> overwhelm the contacts in my Carling Technologies switch? Do I need the
> added complexity of relays? Would 14 AWG wire be needed or preferable?
Charlie, 16AWG is fine. A two pole switch without relays is fine.
You might want to fuse each circuit at 10 or 15A. See:
http://aeroelectric.com/articles/Pitot_Heater/Gauging_Pitot_Heater_Performance.pdf
Bob . . .
Message 16
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Aerospace Logic instruments |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
Good answer Vern!
Bob . . .
At 09:48 AM 2/15/2005 -0800, you wrote:
>--> AeroElectric-List message posted by: rv-9a-online <rv-9a-online@telus.net>
>
>Ken, the purpose of the fuses in the aircraft are to protect the wiring,
>not the instruments. If you follow their advice, and you had a wiring
>short, you could have a combustion event... and the instrument fuse
>would never blow.
>
>Conversely, external fuses are not there to protect the instrument.
>Instruments should have their own internal protection, if required.
>
>Vern Little
Message 17
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Aerospace Logic instruments |
--> AeroElectric-List message posted by: "Ken Simmons" <ken@truckstop.com>
Thanks for the smack upside the head guys. I had forgotten the basic purpose for
the fuse/breaker protection.
Ken
DO NOT ARCHIVE
---------- Original Message ----------------------------------
From: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
>
>Good answer Vern!
>
>Bob . . .
>
>At 09:48 AM 2/15/2005 -0800, you wrote:
>
>>--> AeroElectric-List message posted by: rv-9a-online <rv-9a-online@telus.net>
>>
>>Ken, the purpose of the fuses in the aircraft are to protect the wiring,
>>not the instruments. If you follow their advice, and you had a wiring
>>short, you could have a combustion event... and the instrument fuse
>>would never blow.
>>
>>Conversely, external fuses are not there to protect the instrument.
>>Instruments should have their own internal protection, if required.
>>
>>Vern Little
>
>
Message 18
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Relays for heated pitot tube circuit |
question was Size of Fuse vs. Circuit Breaker - Corrected
--> AeroElectric-List message posted by: <chaztuna@adelphia.net>
---- "Robert L. Nuckolls wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
question was Size of Fuse vs. Circuit Breaker - Corrected
>
>
> >
> >Bob,
> > I have a Piper style heated 12 volt pitot. This unit has 2 heating
> > elements. Each element draws 5 amps and has 16 AWG leads to each element.
> > I would like to a 2-2 style switch to control the heater. Each heater
> > element would have it's own fused circuit running 16AWG wire.
>
>
> > Your previous advice has been that relays are not needed to protect the
> > switch when current draw does not exceed 5 amps. Since this double pole
> > switch will limit warmed up current to 5 amps per set of contacts in the
> > switch, will this be sufficient? Will the high "in rush" current
> > overwhelm the contacts in my Carling Technologies switch? Do I need the
> > added complexity of relays? Would 14 AWG wire be needed or preferable?
>
>
> Charlie, 16AWG is fine. A two pole switch without relays is fine.
> You might want to fuse each circuit at 10 or 15A. See:
>
> http://aeroelectric.com/articles/Pitot_Heater/Gauging_Pitot_Heater_Performance.pdf
>
>
> Bob . . .
Bob,
Wow! What can I say? Thank you! I'd of been happy with a simple yes or no answer.
I got an entire article on the subject.
Charlie Kuss
Message 19
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> AeroElectric-List message posted by: "Jim Stone" <jsto1@tampabay.rr.com>
Stan,
In the Tampa TCA and 30 NM vail, you will need a mode C transponder and
com. Sqawking 1200 under the TCA reduces the need for a com, but it's
nice to be able to call for help in some instances.
Jim Stone
Jabiru J450 at KPIE
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Speedy11@aol.com
Subject: AeroElectric-List: Battery Buss
--> AeroElectric-List message posted by: Speedy11@aol.com
Listers,
Please correct me if I'm wrong. The way I see it, the only reason I
need a
battery buss is to provide always available power for things such as
engine
ignition, clock, or small courtesy lights. If I don't have any of those
things,
then I could do without a battery buss.
Stan Sutterfield
Tampa
www.rv-8a.net
Message 20
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Stereo vs. Mono Headphone Jacks |
--> AeroElectric-List message posted by: "Kingsley Hurst" <khurst@taroom.qld.gov.au>
Bob et al,
This topic reminds me of something I have wanted to know for some time
now. I'm not too frightened to ask a question on this list as others
have suggested but since my knowledge is so limited in this respect, I
am a little embarrassed because I am not sure I really know HOW to ask
the question.
Given that I will have an XCOM 760 com with a built-in VOX intercom, if
I purchase an IPOD and/or an AM/FM radio receiver, what do I need to do
to be able to selectively listen to each in a headset?
I imagine I need something like Bob's Audio Isolation Amplifier but if
this is correct, one of many things I don't understand is where the
inbuilt VOX intercom fits into all of this.
Any help gratefully received thanks but please observe the KISS
principle.
Kingsley Hurst
Europa Classic 281 in Oz
Message 21
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: LED Bias Resistors |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 11:44 AM 2/15/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "John Schroeder"
><jschroeder@perigee.net>
>
>Robert L. Nuckolls, III <b.nuckolls@cox.net> wrote:
>
> > A pair of 220 ohm resistors wired as suggested provides about 35 mA of
> > drive to an LED when the LR-3 is flashing the lamp. 220 was picked
> > because it's a commonly stocked value
>
>Bob -
>
>My problem is that 35 milliamps of current, when the LR-3 provides the
>signal, will put 1.75 times the amount of current specified by the NKK LED
>lamps we are using. I came up with 560 because that gives me a tolerable
>bit of overdrive and I can get the resistors at Radio Shack. That is the
>basis of my original question.
Aha! . . . and entirely different application which probably
doesn't need the parallel resistor unless you're planning on having
one of these switches double as the low volts warning light. Figure
about 2 volts across the lamp and assuming a 14v source, you need
(14-2)/.02 = 600 ohms and 560 is plenty close.
Further, in my experience the modern LED is VERY tolerant to
over-current. We had a bit of a kerfuffle here on the list
a few years ago about this. I fabricated an experiment with
a wall wart wherein I biased up several LEDs at 5x their
rated current (150 versus 30 mA). Plugged them into a little
used outlet in the garage and left them.
Several years later I took them down when I was pulling wall
socket plates off the walls to paint . . . they never got put
back. As far as I could see, all LEDs in the experiment were
still capable of scorching the retinas off the backs of my
eyeballs.
Yeah, if you want the LED to run a bizillion hours, there may
be value in running at or less than specified current. If you
need a bit more light, there's little risk in overdriving the
parts to get it.
Bob . . .
Message 22
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Alternator light misteries |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 04:55 PM 2/15/2005 +0100, you wrote:
>--> AeroElectric-List message posted by: "Hans Teijgeler" <hans@jodel.com>
>
>Hi guys,
>
>I am wiring up a dual battery, single alternator setup using an internally
>regulated ND alternator (55 amp) for a dual computer, dual fuel pump Subaru
>engine.
>
>My system will be somewhat simpler than Z-14 (which has dual batteries, dual
>alternators and a crossfeed function). Basically this:
>
>* Battery A feeds engine bus A
>
>* Battery B feeds engine bus B
>
>* Battery A feeds main power bus (strictly VFR, no electric flaps, trim or
>anything, so all of this electricity is a luxury item and not strictly
>needed, hence no attempt to connect to battery B in case number A fails.
>Tough luck for ATC)
>
>* Battery B feeds starter (I could use two starter solenoids and a toggle
>switch to enable battery B starting as well, but these solenoids are HEAVY).
>Now, normal starting will be with engine on battery A and starter on B. If I
>run down battery A, I can switch to battery and engine bus B, and still use
>the starter.
>
>* Alternator feeds both batteries through a 70 amp diode to each battery.
>
>
>No problems so far (unless you think that I've got this design all wrong),
>until I got to the point of wiring up the alternator light. This one is
>supposed to go to +12V. But which one? The alternator is feeding both
>systems, so I guess either battery A or B would do?
>
>Can someone elaborate on what the true function of this light really is?
>What is it telling me? What if the light bulb breaks, will that affect
>alternator operation? Could I wire in a diode-resistor combo, or does it
>need to be a light bulb? Do I really need this light, or would a negative
>amps alarm on my ammeter(s) make more sense?
It's an alternator fail light which MAY or MAY not tell all the
tales of altenrator failure. I've never bothered to hook one up
going instead with active notification of low voltage such as
described both in a DIY project or off-the-shelf product.
The question I have is why not figure Z-13 with a second battery
added. Run engine dependent stuff from independent battery busses
and simply run two battery contactors. Close only one contactor
for starting. I have a number of builders with this configuration
and as far as I know, it has proven satisfactory and doesn't need
power diodes. Further, the low voltage warning drives from the
main bus as depicted in the diagram.
With respect to your last question, waaaayyyyy back when, some
alternator designs required this lamp for the alternator to
come on line. I don't think this is true any more . . . so if
it were my airplane, I'd just eliminate it and ignore the unused
terminal on the alternator.
Bob . . .
Message 23
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Dual Alternators |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 09:55 AM 2/15/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "Jim Butcher" <europa@triton.net>
>
>I am fitting a second alternator to a Rotax 914. It is a B&C L60 driven off
>the crank shaft so will generate about 40A at 5000 RPM. The circuit I'm
>using is Z-13. Is there a problem in having both alternators "turned on" at
>the same time, ie DC Power Master Switch ON to operate the L60 and the Aux
>Alt ON to operate the S704-1 relay? Seems like some have said the Rotax
>(Ducatti) regulator will not tolerate this.
Is this an academic question or are you planning
to run both alternators at the same time? Having
looked over the schematic of a Ducatti regulator
for the Rotax, I don't think this will hurt it. I'm
curious as to why you're belting the alternator for
reduced power? Why not run an L-40 and set the pulley
ratio for full power and save the dollars and weight
difference between an L40 and the L60?
Bob . . .
Message 24
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Relays for heated pitot tube |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
>
>Bob,
> Wow! What can I say? Thank you! I'd of been happy with a simple yes or
> no answer. I got an entire article on the subject.
>Charlie Kuss
Public schools are rife with individuals who dispense lots of
data with neat yes/no or pick-the-right-box answers on a
multiple-guess test. Real teachers know that one needs to
understand how something works so that when the "student"
encounters run the situation again, they are qualified
to be a "teacher". It's my fondest wish that folks who get
answers from participants here on the list get understanding
as well so that they can be a teacher on that subject in the
future.
Bob . . .
Message 25
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Stereo vs. Mono Headphone Jacks |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 02:50 PM 2/16/2005 +1000, you wrote:
>--> AeroElectric-List message posted by: "Kingsley Hurst"
><khurst@taroom.qld.gov.au>
>
>Bob et al,
>
>This topic reminds me of something I have wanted to know for some time
>now. I'm not too frightened to ask a question on this list as others
>have suggested but since my knowledge is so limited in this respect, I
>am a little embarrassed because I am not sure I really know HOW to ask
>the question.
>
>Given that I will have an XCOM 760 com with a built-in VOX intercom, if
>I purchase an IPOD and/or an AM/FM radio receiver, what do I need to do
>to be able to selectively listen to each in a headset?
>
>I imagine I need something like Bob's Audio Isolation Amplifier but if
>this is correct, one of many things I don't understand is where the
>inbuilt VOX intercom fits into all of this.
>
>Any help gratefully received thanks but please observe the KISS
>principle.
If it were my airplane, I'd add an audio isolation amplifer
that handles the stereo source signals to stereo phone and
mixes monophonic aircraft sources into both right and left
headsets. This eliminates the need for multiple headset jacks
and some of the switches proposed on the list of late.
See: http://www.aeroelectric.com/Catalog/AEC/9009/9009-700E.pdf
Page 1.10 of this document describes how the system you describe
is wired.
Bob . . .
Message 26
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Size of Fuse vs. Circuit Breaker |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
At 10:57 AM 2/12/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: "Bob C. " <flyboy.bob@gmail.com>
>
>Bob,
>
>The reason I asked . . . I'm building a RV-8 that was partially
>completed by another builder . . . he had installed a Gretz Aero
>AN5812 heated pitot. The installation instruction say it will draw
>from 6.4 to 8.0 amps which would put it in the 100W range. The
>predecessor builder had run 16AGW from the pitot to the wing root . .
>.
>
>I was planning on finishing the circuit with 16 and putting a 10A
>switch/breaker in to feed this device. Sounds like it "could be" a
>little light on start up?
Agreed. See:
http://aeroelectric.com/articles/Pitot_Heater/Gauging_Pitot_Heater_Performance.pdf
If you have breakers, a 25A would be more appropriate and 14AWG wire would be
"better". You can switch this with the ordinary toggle switch like
the S700-1-3 from B&C.
>I learn a lot from this list!?
Great!
Bob . . .
Message 27
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Com antenna relay?? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>Comments/Questions: I am installing a second com radio in my homebuilt
>airplane. I want to use an RF coaxial relay to be able to switch between
>two radios and one com antenna. I have an audio panel and can use an aux
>contact on the com selector switch to change the relay position. Are they
>any caveats to doing this? I usually see two antennas on aircraft--one
>for each radio.
Yup, that's so that you can listen on both radios at the
same time. If you use the relay and one antenna, only one radio
works at a time in BOTH transmit and receive modes.
Bob . . .
Message 28
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Stereo vs. Mono Headphone Jacks |
--> AeroElectric-List message posted by: "Kingsley Hurst" <khurst@taroom.qld.gov.au>
Unbelievable Bob, your answer was back exactly 30 min after I posted my
question. I have now printed out this document thank you so will do my
best to understand it.
Best regards
Kingsley
Do not archive.
>
>Given that I will have an XCOM 760 com with a built-in VOX intercom, if
>I purchase an IPOD and/or an AM/FM radio receiver, what do I need to do
>to be able to selectively listen to each in a headset?
>
>I imagine I need something like Bob's Audio Isolation Amplifier but if
>this is correct, one of many things I don't understand is where the
>inbuilt VOX intercom fits into all of this.
>
>Any help gratefully received thanks but please observe the KISS
>principle.
If it were my airplane, I'd add an audio isolation amplifer
that handles the stereo source signals to stereo phone and
mixes monophonic aircraft sources into both right and left
headsets. This eliminates the need for multiple headset jacks
and some of the switches proposed on the list of late.
See: http://www.aeroelectric.com/Catalog/AEC/9009/9009-700E.pdf
Page 1.10 of this document describes how the system you describe
is wired.
Bob . . .
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|