Today's Message Index:
----------------------
1. 05:03 AM - Connection to Diode (William Bernard)
2. 05:12 AM - Re: to Schottky or not to Shottkey, that IS thw question . . . (Robert L. Nuckolls, III)
3. 05:33 AM - Re: Connection to Diode (William Bernard)
4. 06:02 AM - Landing/taxi light warm up (Jay Ferguson)
5. 06:22 AM - Re: Landing Light - on e-buss or main buss??? (Mark Phillips)
6. 06:43 AM - Re: Landing/taxi light warm up (Shannon Knoepflein)
7. 06:59 AM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
8. 07:11 AM - Re: Landing Light - on e-buss or main (Robert L. Nuckolls, III)
9. 07:34 AM - Re: Landing/taxi light warm up (Scott Bilinski)
10. 07:51 AM - Re: Landing/taxi light warm up (Shannon Knoepflein)
11. 08:08 AM - Re: Filter inductor question (Gilles.Thesee)
12. 08:34 AM - Re: Landing Light - on e-buss or main buss??? (Mark Phillips)
13. 08:43 AM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
14. 08:57 AM - Mechanical Latching Battery Disconnect ()
15. 09:19 AM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
16. 10:15 AM - Re: Landing/taxi light warm up (Shannon Knoepflein)
17. 12:29 PM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
18. 12:37 PM - Re: Mechanical Latching Battery Disconnect (Robert L. Nuckolls, III)
19. 12:59 PM - Re: Mechanical Latching Battery Disconnect ()
20. 02:16 PM - Need a vaccum pump with a pulley. (cecilth@juno.com)
21. 02:29 PM - panel pix (Shannon Knoepflein)
22. 02:29 PM - Re: Landing/taxi light warm up (Shannon Knoepflein)
23. 03:06 PM - Re: Mechanical Latching Battery Disconnect (Robert L. Nuckolls, III)
24. 04:09 PM - Re: Landing/taxi light warm up (fellowsw)
25. 04:28 PM - Re: Need a vaccum pump with a pulley. (RSwanson)
26. 05:24 PM - Re: Mechanical Latching Battery Disconnect ()
27. 07:36 PM - Re: Mechanical Latching Battery Disconnect (Robert L. Nuckolls, III)
28. 07:56 PM - Re: Landing/taxi light warm up (David Carter)
29. 08:19 PM - Colorado Seminar Date Set (Robert L. Nuckolls, III)
30. 08:32 PM - Re: Mechanical Latching Battery Disconnect ()
31. 08:36 PM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
32. 08:39 PM - Re: Landing/taxi light warm up (Robert L. Nuckolls, III)
33. 08:55 PM - PM Alternator run ok without battery? ()
34. 09:17 PM - Re: Mechanical Latching Battery Disconnect (David Carter)
35. 09:39 PM - Matronics ISP Upgrade COMPLETED! (Matt Dralle)
36. 09:45 PM - instrument protection (Joel Harding)
37. 09:47 PM - Re: Landing/taxi light warm up (fellowsw)
38. 11:28 PM - Re: Re: to Schottky or not to Shottkey, that IS (Jerzy Krasinski)
Message 1
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| Subject: | Connection to Diode |
--> AeroElectric-List message posted by: "William Bernard" <billbernard@worldnet.att.net>
I'm gathering parts for the wiring job and have what is probably a dumb question.
The aircraft will be wired following Bob's Z-13 diagram. This calls for #6
wires from the battery contactor to the Main and E-busses. the wires go through
the diode to the e-buss.
Here's the question. Is there a fast-on connector for the #6 wire? B&C lists only
ring type connectors on the web site. Or is #6 overkill and is a smaller wire
suitable?
Thanks
Bill
Message 2
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| Subject: | Re: to Schottky or not to Shottkey, that IS thw question |
. . .
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 12:02 AM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Jerzy Krasinski
><krasinski@direcway.com>
>
>Schottky diodes for 20A are in fact quite common, but not in Radio
>Shack. Check www.digikey.com. Search for International Rectifier
>Schottky rectifiers. You will find at least a hundred of different
>Schottky diodes with max current anywhere between 20A and 400A.
>The diodes between 20A and 40A cost roughly between $1 and $3, depending
>on voltage . Those good for 40A to 80A cost anywhere between $3 and $10.
>Digikey accepts telephone or email orders.
>Jerzy
Availability wasn't the driving consideration. I've used
Schottky diodes for years in designs where package didn't
particularly matter and unique performance characteristics
were desired.
The decision to recommend the bridge rectifier assembly
came from the fact that it mounts easily as supplied . . .
no brackets, insulating washers or solder joints required.
They come fitted with 1/4" fast-on tabs ready to bolt to
some handy surface between the e-bus and main-bus fuse
blocks. No effort other than to buy it, bolt it and wire
it. Diode arrays rated up to 35 amps in this package
were readily available from many suppliers.
Eric's product requires his manufacturing time to put
the raw device into a user friendly package. Fine
if you need the unique performance of the Schottky
device. There's nothing wrong with using this
product in your airplane . . . I'd like for
folks to make the decision based on knowledgeable
evaluation of fact and not upon shop-worn myths
or marketing hype.
Bob . . .
Message 3
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| Subject: | Re: Connection to Diode |
--> AeroElectric-List message posted by: "William Bernard" <billbernard@worldnet.att.net>
Nevermind, I found the answer. It's #16 wire that connects to the diode, not #6.
(Gotta' get these bifocals adjusted...)
Bill
Message 4
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: Jay Ferguson <jayferg@midsouth.rr.com>
I read somewhere about some sort of resistor that could be used in
light circuits to protect incandescent lamps when they were switched
on. It would initially have high resistance which would drop quickly
when warmed by current flow. The ramp-up to full brightness would not
be so slow as to be bothersome but would offer some protection to the
lamp's cold filament. Is anyone familiar with this resistor and is it
worth the effort to incorporate them into an OBAM electrical system?
Thx,
Jay Ferguson
Message 5
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| Subject: | Re: Landing Light - on e-buss or main buss??? |
--> AeroElectric-List message posted by: Mark Phillips <ripsteel@edge.net>
I have the diode assy from B&C and wish to also place my taxi light on the E-bus
as
backup for master contactor failure. This drives E-bus max current into the
neighborhood of 20 amps, if a 100w bulb were installed (planning on 55w, but a
100w
bulb CAN be installed) The Connection indicates a heat sink is required if the
diode
is driven over 3-4 amps. Mouser does not carry the same heat sink as DigiKey,
but a
similar one is Mouser part# 532-568303B00 on page692. Search at:
http://www.mouser.com//index.cfm?handler=productsearch._searchform
Does this one look like it will work as well, or would it be better to go with
the
Schottke mentioned below?
Also, can the feed side terminals of the diode assembly be jumpered together to
utilize 2 of the diodes within? Any advantage here? (less load on one diode, better
heat dissipation or less voltage drop across parallel diodes?)
The above load also requires protecting the E-bus at 20 amps- As mentioned on the
Aeroelectric website the B&C fuseblocks are rated at 30, but cautioned to not use
over 15 amps per circuit. I was planning to feed the diode with a 20 amp fuse
from
the main bus fuseblock. Is this acceptable?
The alternate e-bus feed will require 12AWG wire. Can I make a short 16AWG fuselink
to protect this or would an inline fuse be preferred? Can I also crimp this wire
into the terminal for the + battery cable along with the fat wire to eliminate
a
separate connector stacked on the battery terminal? (have access to BIG crimper)
Thanks for all the assistance and apologies for the deviant behavior!
Mark Phillips
Shannon Knoepflein wrote:
> --> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
>
> My point was I think that the devices that Eric is building are a step
> in the right direction for OBAM aircraft (these include several solid
> state relay devices in addition to the diodes). Also, considering
> Eric's diode is the only one readily available that will handle the 20A
> my one buss requires is significant.
>
> As always, thanks for setting me straight and putting it all in
> perspective. Your vast understanding in really incredible. Thanks.
>
>
Message 6
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
I think you are looking for a current limiter. These come packaged in
small discs with 2 leads off of them, sort of look like a disc
capacitor. These are used to limit the inrush current when you first
turn a light on until the filament heats up. They are available from
sources like digikey, etc. I am using these on my landing and taxi
lights.
---
Shannon Knoepflein <---> kycshann@kyol.net
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jay
Ferguson
Subject: AeroElectric-List: Landing/taxi light warm up
--> AeroElectric-List message posted by: Jay Ferguson
<jayferg@midsouth.rr.com>
I read somewhere about some sort of resistor that could be used in
light circuits to protect incandescent lamps when they were switched
on. It would initially have high resistance which would drop quickly
when warmed by current flow. The ramp-up to full brightness would not
be so slow as to be bothersome but would offer some protection to the
lamp's cold filament. Is anyone familiar with this resistor and is it
worth the effort to incorporate them into an OBAM electrical system?
Thx,
Jay Ferguson
Message 7
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| Subject: | Re: Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 07:59 AM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Jay Ferguson
><jayferg@midsouth.rr.com>
>
>I read somewhere about some sort of resistor that could be used in
>light circuits to protect incandescent lamps when they were switched
>on. It would initially have high resistance which would drop quickly
>when warmed by current flow. The ramp-up to full brightness would not
>be so slow as to be bothersome but would offer some protection to the
>lamp's cold filament. Is anyone familiar with this resistor and is it
>worth the effort to incorporate them into an OBAM electrical system?
>
>Thx,
>Jay Ferguson
See inrush current limiters at
http://dkc3.digikey.com/PDF/T031/0731.pdf
I incorporated one of these into the taxi light
on the GP-180 at lear about 20 years ago. I'm unaware
of any more applications since. If you're using $high$
"aircraft" lamps, they might be worth the trouble.
Use $low$ automotive or industrial halogen lamps
and you'll get many times the life without the
inrush limiters and far less cost.
Bob . . .
Message 8
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| Subject: | Re: Landing Light - on e-buss or main |
buss???
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:17 AM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Mark Phillips <ripsteel@edge.net>
>
>I have the diode assy from B&C and wish to also place my taxi light on the
>E-bus as
>backup for master contactor failure. This drives E-bus max current into the
>neighborhood of 20 amps, if a 100w bulb were installed (planning on 55w,
>but a 100w
>bulb CAN be installed)
Why install a 100W? If this is the back up, what is the value
added by increasing the size of the lamp?
> The Connection indicates a heat sink is required if the diode
>is driven over 3-4 amps. Mouser does not carry the same heat sink as
>DigiKey, but a
>similar one is Mouser part# 532-568303B00 on page692. Search at:
>http://www.mouser.com//index.cfm?handler=productsearch._searchform
>
>Does this one look like it will work as well, or would it be better to go
>with the
>Schottke mentioned below?
First, if having some kind of exterior lighting available
when all else fails is of concern to you, I'd run the
lamp from a battery bus. Use an S704-1 relay right at the battery bus
You can power the relay from the e-bus to make sure it
doesn't get left on after the battery master and e-bus
alternate feeds are shut down. Give the lamp its own
fuse on the battery bus. Alternatively you can consider
one of Eric's solid state relays.
>Also, can the feed side terminals of the diode assembly be jumpered
>together to
>utilize 2 of the diodes within? Any advantage here? (less load on one
>diode, better
>heat dissipation or less voltage drop across parallel diodes?)
>
>The above load also requires protecting the E-bus at 20 amps- As mentioned
>on the
>Aeroelectric website the B&C fuseblocks are rated at 30, but cautioned to
>not use
>over 15 amps per circuit. I was planning to feed the diode with a 20 amp
>fuse from
>the main bus fuseblock. Is this acceptable?
>
>The alternate e-bus feed will require 12AWG wire. Can I make a short
>16AWG fuselink
>to protect this or would an inline fuse be preferred? Can I also crimp
>this wire
>into the terminal for the + battery cable along with the fat wire to
>eliminate a
>separate connector stacked on the battery terminal? (have access to BIG
>crimper)
>
>Thanks for all the assistance and apologies for the deviant behavior!
Using relay makes all these issues go away. I'd recommend
you keep the e-bus loads limited to true endurance issues.
Bob . . .
Message 9
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: Scott Bilinski <bilinski@kyocera-wireless.com>
There is another method which keeps the filiment warm by suppying 10% (?)
power to it. Not sure how this is done though.
At 09:40 AM 4/2/03 -0500, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>I think you are looking for a current limiter. These come packaged in
>small discs with 2 leads off of them, sort of look like a disc
>capacitor. These are used to limit the inrush current when you first
>turn a light on until the filament heats up. They are available from
>sources like digikey, etc. I am using these on my landing and taxi
>lights.
>
>---
>Shannon Knoepflein <---> kycshann@kyol.net
>
>-----Original Message-----
>From: owner-aeroelectric-list-server@matronics.com
>[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jay
>Ferguson
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Landing/taxi light warm up
>
>--> AeroElectric-List message posted by: Jay Ferguson
><jayferg@midsouth.rr.com>
>
>I read somewhere about some sort of resistor that could be used in
>light circuits to protect incandescent lamps when they were switched
>on. It would initially have high resistance which would drop quickly
>when warmed by current flow. The ramp-up to full brightness would not
>be so slow as to be bothersome but would offer some protection to the
>lamp's cold filament. Is anyone familiar with this resistor and is it
>worth the effort to incorporate them into an OBAM electrical system?
>
>Thx,
>Jay Ferguson
>
>
Scott Bilinski
Eng dept 305
Phone (858) 657-2536
Pager (858) 502-5190
Message 10
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
Wouldn't it be easier on the switches and/or relays (or SSR's in my
case) to have these limiters to keep the current in check on circuits
like my 4 75W taxi/landing lights? I would think the life of the
contacts would improve?
---
Shannon Knoepflein <---> kycshann@kyol.net
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: Re: AeroElectric-List: Landing/taxi light warm up
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 07:59 AM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Jay Ferguson
><jayferg@midsouth.rr.com>
>
>I read somewhere about some sort of resistor that could be used in
>light circuits to protect incandescent lamps when they were switched
>on. It would initially have high resistance which would drop quickly
>when warmed by current flow. The ramp-up to full brightness would not
>be so slow as to be bothersome but would offer some protection to the
>lamp's cold filament. Is anyone familiar with this resistor and is it
>worth the effort to incorporate them into an OBAM electrical system?
>
>Thx,
>Jay Ferguson
See inrush current limiters at
http://dkc3.digikey.com/PDF/T031/0731.pdf
I incorporated one of these into the taxi light
on the GP-180 at lear about 20 years ago. I'm unaware
of any more applications since. If you're using $high$
"aircraft" lamps, they might be worth the trouble.
Use $low$ automotive or industrial halogen lamps
and you'll get many times the life without the
inrush limiters and far less cost.
Bob . . .
Message 11
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| Subject: | Re: Filter inductor question |
--> AeroElectric-List message posted by: "Gilles.Thesee" <Gilles.Thesee@ac-grenoble.fr>
Thank you Bob,
> >But we have lots of 15 V, 1.3 watt or even 5 watt Zener diodes (1N5352B).
> >Will that do for the filter ? Maybe a single 5 watt Zener will be up to
the
> >job ?
>
> That would do fine. I like the 1W glass devices because
> they fail shorted rather quickly and do a sort of one-part
> crowbar effort against the fuse
Hey, that's clever.
(you ARE using a fuse
> to feed this thing?).
Yes sir. 2 or 3 amps fuse on the fuse block.
I've not tested a larger zener
> but it's very likely to be a suitable substitute.
>
Thanks,
Gilles
Message 12
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| Subject: | Re: Landing Light - on e-buss or main buss??? |
--> AeroElectric-List message posted by: Mark Phillips <ripsteel@edge.net>
> Using relay makes all these issues go away. I'd recommend
> you keep the e-bus loads limited to true endurance issues.
Very well- in the interest of KISS, will re-locate taxi to main, supply E-bus "by
the book"
The likelihood of master contactor + alt failure (spent the big bux for a B&C)
are pretty
remote.........
One more Q please: For packaging considerations, I need to reverse the fat wires
on the
master contactor. Any problem with this provided the diode and coil feed wire
are switched
around?
Can't thank you enough for all the assistance- any neophyte trying to wire his/her
plane
without the A-list must be insane!! Heap-O-Thanx, Bob & Matt
This Nuckollhead crying "uncle!" at The PossumWorks
Mark
Message 13
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 07:31 AM 4/2/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: Scott Bilinski
><bilinski@kyocera-wireless.com>
>
>There is another method which keeps the filiment warm by suppying 10% (?)
>power to it. Not sure how this is done though.
Covered in detail in chapter 12 . . .
and 1% is more than sufficient.
Bob . . .
Message 14
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| Subject: | Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: <315@cox.net>
Bob,
Just wondered if you have run across the following:
http://www.hotronicsproducts.com/circuit.htm
It is typically used by Street Rodders to kill all power drains on the
battery. They often store their Street Rods between shows and they had
problems with things (Alternator Regulators, clocks, etc) running the
battery down. This battery disconnect was developed as a solution. The
vendor says he sells a couple hundered each month.
It purpports to be a mechnical latching contactor. It does not require
electrical holding power so that no electricity is being consumed while it
is engaged. A momentary switch energizes the solenoid and then a mechanical
catch holds it in place and then the current is turned off. Same in reverse
for opening the battery circuit. It can be jarred open. For example one
fellow had it hard mounted on the Street Rod frame. His street rod had
virtually no suspension. When he crossed a railroad track at a high enough
speed the disconnect would jarre open. His solution was to remount on the
Street Rod body which in turn cushioned the jar enough to prevent
recurrance. Perhaps the jar open feature would be good in the event of an
airplane crash.
I was thinking of using this for my battery contactor.
What are your thoughts?
Thanks,
Ned
Message 15
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:47 AM 4/2/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>Wouldn't it be easier on the switches and/or relays (or SSR's in my
>case) to have these limiters to keep the current in check on circuits
>like my 4 75W taxi/landing lights? I would think the life of the
>contacts would improve?
How big is 'improve' . . . if the rated performance of
the switch is tens of thousands of operations with
a resistive load and drops to, say 2,000 operations
with a lamp load . . . how long will it take you
to wear out the switch? If you fly twice a week
and get 4 operations per flight, you'll get
a calendar service life of more than 5 years.
For the most part, switches in light airplanes die
of old age and not from in-service operational
stresses . . . no matter how you load them. I fly
airplanes pushing 40 years old with the original,
10A resistive rated landing light switches humming
right along.
Keep-warm and inrush-limiting have a nice ring
to them intellectually. I've designed inrush
limiters for 200A a/c compressor motors that have
1200A inrush capabilities . . . to keep from
bumping the bus too hard on a biz-jet . . . aside
from this special case, I have yet to identify
much value for incorporating this feature in
a light aircraft. This design philosophy will be
removed from the next revision to chapter 12.
Bob . . .
Message 16
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
I guess the only real benefit then would be the longer lasting light
bulbs for standard relays and switches. It still seems they would be
warranted for the new solid state relays, which is why Eric suggested
them, and mainly why I am using them. If you don't think they are
warranted for this application, by all means let me know....one part to
remove and one less thing to fail.
Speaking of failure, what actually is involved on the inside of a
current limiter, ie, whats the physics behind its operation. I'm
guessing sort of like a resistor with opposite temperature properties?
When its cold, high resistance, heat it up and it goes to practically
zero?
---
Shannon Knoepflein <---> kycshann@kyol.net
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: RE: AeroElectric-List: Landing/taxi light warm up
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 10:47 AM 4/2/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>Wouldn't it be easier on the switches and/or relays (or SSR's in my
>case) to have these limiters to keep the current in check on circuits
>like my 4 75W taxi/landing lights? I would think the life of the
>contacts would improve?
How big is 'improve' . . . if the rated performance of
the switch is tens of thousands of operations with
a resistive load and drops to, say 2,000 operations
with a lamp load . . . how long will it take you
to wear out the switch? If you fly twice a week
and get 4 operations per flight, you'll get
a calendar service life of more than 5 years.
For the most part, switches in light airplanes die
of old age and not from in-service operational
stresses . . . no matter how you load them. I fly
airplanes pushing 40 years old with the original,
10A resistive rated landing light switches humming
right along.
Keep-warm and inrush-limiting have a nice ring
to them intellectually. I've designed inrush
limiters for 200A a/c compressor motors that have
1200A inrush capabilities . . . to keep from
bumping the bus too hard on a biz-jet . . . aside
from this special case, I have yet to identify
much value for incorporating this feature in
a light aircraft. This design philosophy will be
removed from the next revision to chapter 12.
Bob . . .
Message 17
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 01:11 PM 4/2/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>I guess the only real benefit then would be the longer lasting light
>bulbs for standard relays and switches. It still seems they would be
>warranted for the new solid state relays, which is why Eric suggested
>them, and mainly why I am using them. If you don't think they are
>warranted for this application, by all means let me know....one part to
>remove and one less thing to fail.
Life IS a real issue with aviation lamps which tend to be
old technology, relatively short lived and expensive when
compared to modern automotive and commercial halogen
lamps. If it were my airplane and I could live with a
leading edge installation, I'd work really hard to get
this lamp installed in my leading edges:
http://216.55.140.222/temp/4352.JPG
It's short, halogen, dual filament and 55w. One of these
critters on each wing gives you hi-landing/lo-taxi lighting
and four (count 'em) FOUR filaments putting light out the
front.
Given that these run for YEARS on automobiles without pre-warming
or inrush limiting, they should last the lifetime of most
airplanes.
>Speaking of failure, what actually is involved on the inside of a
>current limiter, ie, whats the physics behind its operation. I'm
>guessing sort of like a resistor with opposite temperature properties?
>When its cold, high resistance, heat it up and it goes to practically
>zero?
Yes, it's a high current component with a negative
coefficient of resistance with respect to temperature.
Take a look at this excerpt from the Digikey catalog
http://216.55.140.222/temp/0731.pdf
Note that p/n KC023L has a room temperature resistance
of 1.3 ohms. Put this in series with system wiring and
a 100W light bulb with a total cold resistance of perhaps
200 milliohms gives you a total loop resistance of 1.5 ohms.
Hit this with 14v and you get 9.3 A inrush as opposed to
70 A inrush with the limiter out of the circuit.
As the limiter heats up, resistance drops to 40
milliohms. If your lamp draws 8A normally, then
8A x 0.04 Ohms gives you a .32 volts drop in the
limiter . . . usually acceptable in terms of
performance.
The trick to using these critters is that they
MUST be allowed to heat up. The first time they
installed one on the GP-180, the critter blew up.
One of experimental flight's techs came over to
show me the wreckage. He'd mounted it inside the
taxi light housing on the nose gear with a metal
clamp that caused a lot of heat to be sinked away
from the device. Power dissipation was not allowed
to warm the device up and it went into self destruct.
I bought some fiberglass sleeving used to seal doors
on wood-burning stoves. Wrapping the inrush limiter
with this material under the clamp allowed it to be
mounted to structure and still warm up so that it
could protect itself.
If you have them installed, I'd leave 'em in. They
do accomplish a useful function and will keep your
panel lights from dimming so much when you turn
on landing or taxi lights. Just be aware of (1) the
need to let them warm up and (2) mounting in a way
that reduces probability of vibration induced cracks
in their solid wire leads. Beyond these cautions,
they should be VERY long lived.
Bob . . .
Message 18
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:56 AM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: <315@cox.net>
>
>Bob,
>
>Just wondered if you have run across the following:
>
>http://www.hotronicsproducts.com/circuit.htm
>
>It is typically used by Street Rodders to kill all power drains on the
>battery. They often store their Street Rods between shows and they had
>problems with things (Alternator Regulators, clocks, etc) running the
>battery down. This battery disconnect was developed as a solution. The
>vendor says he sells a couple hundered each month.
>
>It purpports to be a mechnical latching contactor. It does not require
>electrical holding power so that no electricity is being consumed while it
>is engaged. A momentary switch energizes the solenoid and then a mechanical
>catch holds it in place and then the current is turned off. Same in reverse
>for opening the battery circuit. It can be jarred open. For example one
>fellow had it hard mounted on the Street Rod frame. His street rod had
>virtually no suspension. When he crossed a railroad track at a high enough
>speed the disconnect would jarre open. His solution was to remount on the
>Street Rod body which in turn cushioned the jar enough to prevent
>recurrance. Perhaps the jar open feature would be good in the event of an
>airplane crash.
>
>I was thinking of using this for my battery contactor.
>
>What are your thoughts?
Aside from having to support 10W or so of wasted power
to keep a conventional contactor closed, what benefit
do you perceive? It's SOP to turn off all switches
before an unplanned but anticipated arrival with the
earth (generally done at approach to landing speeds).
Unplanned and un-anticipated arrivals happen
at higher speeds and involve severe reduction in
volume of your airframe wherein automatic battery
disconnect is probably way down on your list
of concerns.
If you have an 18A Rotax alternator and really
need to save battery contactor energy, consider
a manual switch that operates when you want it to
and offers no surprises.
Bob . . .
Message 19
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: <315@cox.net>
I have an RV6A with a Chevy V6 engine that has an ellectrically depenent
ignition system (coil & contacts). In the event of alternator failure I want
to maximize battery life for the ignition system. The battery is in the
tail cone.
Ned
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Mechanical Latching Battery Disconnect
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 10:56 AM 4/2/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: <315@cox.net>
> >
> >Bob,
> >
> >Just wondered if you have run across the following:
> >
> >http://www.hotronicsproducts.com/circuit.htm
> >
> >It is typically used by Street Rodders to kill all power drains on the
> >battery. They often store their Street Rods between shows and they had
> >problems with things (Alternator Regulators, clocks, etc) running the
> >battery down. This battery disconnect was developed as a solution. The
> >vendor says he sells a couple hundered each month.
> >
> >It purpports to be a mechnical latching contactor. It does not require
> >electrical holding power so that no electricity is being consumed while
it
> >is engaged. A momentary switch energizes the solenoid and then a
mechanical
> >catch holds it in place and then the current is turned off. Same in
reverse
> >for opening the battery circuit. It can be jarred open. For example one
> >fellow had it hard mounted on the Street Rod frame. His street rod had
> >virtually no suspension. When he crossed a railroad track at a high
enough
> >speed the disconnect would jarre open. His solution was to remount on
the
> >Street Rod body which in turn cushioned the jar enough to prevent
> >recurrance. Perhaps the jar open feature would be good in the event of an
> >airplane crash.
> >
> >I was thinking of using this for my battery contactor.
> >
> >What are your thoughts?
>
> Aside from having to support 10W or so of wasted power
> to keep a conventional contactor closed, what benefit
> do you perceive? It's SOP to turn off all switches
> before an unplanned but anticipated arrival with the
> earth (generally done at approach to landing speeds).
> Unplanned and un-anticipated arrivals happen
> at higher speeds and involve severe reduction in
> volume of your airframe wherein automatic battery
> disconnect is probably way down on your list
> of concerns.
>
> If you have an 18A Rotax alternator and really
> need to save battery contactor energy, consider
> a manual switch that operates when you want it to
> and offers no surprises.
>
> Bob . . .
>
>
Message 20
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| Subject: | Need a vaccum pump with a pulley. |
--> AeroElectric-List message posted by: cecilth@juno.com
I need a vaccum pump with a pulley.
Where to get a reliable one.
I bought a rebuilt auto pump but I don't trust it.
Can any of the Lycoming pumps be converted to a pulley?
Cecil
Hatfield
Message 21
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--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
BTW, new pix are up of my panel fired up in the plane. Only let the
smoke out of one wire in my haste :)
http://shannon.v8eaters.com/images/lancair/04_2003 (look for panel pix
and video)
Enjoy!!!
And Bob, thanks for helping me get to this point with what has to be the
most reliable electrical system ever built for a Legacy (or any airplane
for that matter). I've learned a lot.
---
Shannon Knoepflein <---> kycshann@kyol.net
Message 22
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
They are mounted inline with the wire in the gear well picture I
attached. They are about the size of a quarter, and will sit outboard
of the strobe power supply you can see in the picture. I need to figure
out some way to protect them and mount them that will allow them to heat
up. What do you think of firesleeve or something over them, or will
heatshrink suffice? The insulation you mention, would this work in this
application? I can't picture the stuff you are talking about.
Also, seeing the strobe power supply reminded me of a question I had
about strobe wiring. The strobe power supply is said to draw a max of
7A. I imagine its less than that. The supplied 3 conductor shielded
cable that comes with the strobe kit is 18 guage, which seems like way
overkill (and quite cumbersome to run in the tight confines that I'm
left with), especially considering there are 3 bulbs being powered from
the supply. In your opinion, would 22-3 shielded suffice?
As always, thanks a ton. If you want it, you are definitely due a ride
in this machine when I get it in the air.
---
Shannon Knoepflein <---> kycshann@kyol.net
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: RE: AeroElectric-List: Landing/taxi light warm up
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 01:11 PM 4/2/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Shannon Knoepflein"
><kycshann@kyol.net>
>
>I guess the only real benefit then would be the longer lasting light
>bulbs for standard relays and switches. It still seems they would be
>warranted for the new solid state relays, which is why Eric suggested
>them, and mainly why I am using them. If you don't think they are
>warranted for this application, by all means let me know....one part to
>remove and one less thing to fail.
Life IS a real issue with aviation lamps which tend to be
old technology, relatively short lived and expensive when
compared to modern automotive and commercial halogen
lamps. If it were my airplane and I could live with a
leading edge installation, I'd work really hard to get
this lamp installed in my leading edges:
http://216.55.140.222/temp/4352.JPG
It's short, halogen, dual filament and 55w. One of these
critters on each wing gives you hi-landing/lo-taxi lighting
and four (count 'em) FOUR filaments putting light out the
front.
Given that these run for YEARS on automobiles without pre-warming
or inrush limiting, they should last the lifetime of most
airplanes.
>Speaking of failure, what actually is involved on the inside of a
>current limiter, ie, whats the physics behind its operation. I'm
>guessing sort of like a resistor with opposite temperature properties?
>When its cold, high resistance, heat it up and it goes to practically
>zero?
Yes, it's a high current component with a negative
coefficient of resistance with respect to temperature.
Take a look at this excerpt from the Digikey catalog
http://216.55.140.222/temp/0731.pdf
Note that p/n KC023L has a room temperature resistance
of 1.3 ohms. Put this in series with system wiring and
a 100W light bulb with a total cold resistance of perhaps
200 milliohms gives you a total loop resistance of 1.5 ohms.
Hit this with 14v and you get 9.3 A inrush as opposed to
70 A inrush with the limiter out of the circuit.
As the limiter heats up, resistance drops to 40
milliohms. If your lamp draws 8A normally, then
8A x 0.04 Ohms gives you a .32 volts drop in the
limiter . . . usually acceptable in terms of
performance.
The trick to using these critters is that they
MUST be allowed to heat up. The first time they
installed one on the GP-180, the critter blew up.
One of experimental flight's techs came over to
show me the wreckage. He'd mounted it inside the
taxi light housing on the nose gear with a metal
clamp that caused a lot of heat to be sinked away
from the device. Power dissipation was not allowed
to warm the device up and it went into self destruct.
I bought some fiberglass sleeving used to seal doors
on wood-burning stoves. Wrapping the inrush limiter
with this material under the clamp allowed it to be
mounted to structure and still warm up so that it
could protect itself.
If you have them installed, I'd leave 'em in. They
do accomplish a useful function and will keep your
panel lights from dimming so much when you turn
on landing or taxi lights. Just be aware of (1) the
need to let them warm up and (2) mounting in a way
that reduces probability of vibration induced cracks
in their solid wire leads. Beyond these cautions,
they should be VERY long lived.
Bob . . .
Message 23
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:59 PM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: <315@cox.net>
>
>I have an RV6A with a Chevy V6 engine that has an ellectrically depenent
>ignition system (coil & contacts). In the event of alternator failure I want
>to maximize battery life for the ignition system. The battery is in the
>tail cone.
Electrically dependent engine stuff should run
directly from the battery bus.
If you walk up to a J-3 and flip the mag switches
ON, the engine is HOT and that airplane doesn't
even have an electrical system. If that's an
acceptable condition, why not wire your electrically
outfitted aircraft for the same behavior?
If it were my airplane, I'd like to be able to shut
of the battery master and e-bus alternate feed any
time there's bad smells in the cockpit WITHOUT having
the engine stop.
Bob . . .
Message 24
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "fellowsw" <fellows.w@ewcapital.net>
With respect to the recommended halogen taxi/landing lights, how do they
compare to production aircraft lights in terms of lighting ability? Do you
measure that in terms of candlepower and angular spread at a distance? What
are reasonable standards for illumination in terms of approach speed? Even
the GE4509 seems to me to be much brighter at a distance than an automobile
halogen light or the hid light.
Another question, if using circuit breakers with fast on tabs, what are the
options for mounting the tabs on a stock brass buss bar?
Walter Fellows
Message 25
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| Subject: | Re: Need a vaccum pump with a pulley. |
--> AeroElectric-List message posted by: RSwanson <rswan19@comcast.net>
You might want to check the racing pumps. Here is one:
http://www.moroso.com/catalog/categorydisplay.asp?catcode=17200
R
----- Original Message -----
From: <cecilth@juno.com>
Subject: AeroElectric-List: Need a vaccum pump with a pulley.
> --> AeroElectric-List message posted by: cecilth@juno.com
>
>
> I need a vaccum pump with a pulley.
> Where to get a reliable one.
> I bought a rebuilt auto pump but I don't trust it.
> Can any of the Lycoming pumps be converted to a pulley?
> Cecil
> Hatfield
>
>
>
>
>
>
Message 26
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: <315@cox.net>
Hi Bob,
Sorry to belabor this.
I'm not real clear on how to do what you are suggesting...
I thought it important to be able to isolate the battery. It is located
behind the occupants in the tail cone. Currently the Battery disconnect is
in front of the occupants under the panel. That leaves the battery lead
running under one of the occupants arms. It just seemed to make sense that
one should be able to cut the power from this main battery lead in the event
it were to short out in the cabin.
But if this is not really that risky then it would seem that my current
configuration is acceptable with the disconnect contactor under the panel.
I could extend the hot side of the contactor to an ignition switch that
would provide the battery power to the ignition. That way I could
de-energize the battery contactor opening all circuits except the ignition.
Is this close to what you mean by your post?
Thanks again,
Ned
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Mechanical Latching Battery Disconnect
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 02:59 PM 4/2/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: <315@cox.net>
> >
> >I have an RV6A with a Chevy V6 engine that has an ellectrically depenent
> >ignition system (coil & contacts). In the event of alternator failure I
want
> >to maximize battery life for the ignition system. The battery is in the
> >tail cone.
> Electrically dependent engine stuff should run
> directly from the battery bus.
>
> If you walk up to a J-3 and flip the mag switches
> ON, the engine is HOT and that airplane doesn't
> even have an electrical system. If that's an
> acceptable condition, why not wire your electrically
> outfitted aircraft for the same behavior?
>
> If it were my airplane, I'd like to be able to shut
> of the battery master and e-bus alternate feed any
> time there's bad smells in the cockpit WITHOUT having
> the engine stop.
>
> Bob . . .
>
>
Message 27
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 07:24 PM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: <315@cox.net>
>
>Hi Bob,
>
>Sorry to belabor this.
>
>I'm not real clear on how to do what you are suggesting...
>
>I thought it important to be able to isolate the battery. It is located
>behind the occupants in the tail cone. Currently the Battery disconnect is
>in front of the occupants under the panel. That leaves the battery lead
>running under one of the occupants arms. It just seemed to make sense that
>one should be able to cut the power from this main battery lead in the event
>it were to short out in the cabin.
Sure . . there's a BATTERY MASTER contactor right at the
battery. Open the battery master switch and everything
but the battery bus goes cold. You have a battery bus right
at the battery location too. Low current feeds (FAA likes to
see 5A or less, I'm comfortable with 7A if fused, not breakered)
drive directly from the battery bus. If you have higher current
needs, then a mini-contactor, or fat-relay (like the S704 or
it's solid state equal) is used to make feeds larger than
7A cold right at the bus. Your e-bus alternate feed comes
from the battery bus, your engine dependent needs come from
the battery bus.
>But if this is not really that risky then it would seem that my current
>configuration is acceptable with the disconnect contactor under the panel.
>I could extend the hot side of the contactor to an ignition switch that
>would provide the battery power to the ignition. That way I could
>de-energize the battery contactor opening all circuits except the ignition.
>Is this close to what you mean by your post?
Battery contactors and all other controls for more than
5A feeders should unhook right at the battery. It would
be best if anything larger than 5A did not venture more than
a few inches from the battery location before it hits
a pilot controlled disconnect.
See this hypothetical:
http://216.55.140.222/temp/batbus.pdf
Here I show a battery bus and a battery contactor
right next to the battery. A FAT wire comes off the
contactor to the starter contactor and main bus.
A battery bus can drive a 1A protected lead of any
length to a clock . . .
. . . a 1A protected lead to the hour-meter.
. . . a 3A protected lead to a switch
for a Kettering ignition.
. . . a 7A protected lead gets a local disconnect
relay for the e-bus alternate feed that's burdened
with big transmitter and/or perhaps gyros. This could
be a 10A feeder. The point is that long, always hot
wires protected at over 5A need pilot controlled
disconnect in close proximity to the bus.
. . . if you're fuel injected and need a hi-pressure
squirter fused at 10A, it gets a relay too.
. . . a 1A courtesy light can go as far as needs
be with no special concerns.
This is what I'd have to do to sell this or a
similar system to the FAA . . . it has to do
with crash safety. Always hot wires from the
battery are either pilot controllable or
limited to 5A or less. I've seen them allow
breakers but fuses are MUCH faster and offer
even greater safety.
We've got a lot of builders who have built
some pretty hefty e-busses . . . with bigger
than 5A feeders for the alternate feed path.
If it were my airplane, I'd use the local
disconnect relay as shown for a budget of
about 100 mA to keep the relay closed. Or
better yet, a solid state relay with a 10 mA
budget.
If I understand your hypothetical, you were
going to have a LONG, FAT feeder from the
battery coming forward to the battery contactor.
This WOULD function but it's not recommended.
Bob . . .
Message 28
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| Subject: | Re: Landing/taxi light warm up |
--> AeroElectric-List message posted by: "David Carter" <dcarter@datarecall.net>
Bob,
Before you remove the design philosophy from Chap 12, I'd like to mention
this: I fly missions with CAP, which is gung-ho on "wig-wag" landing-taxi
light flashing. Was no problem until leaving mission base after an all day
search, stopped in Austin for supper, came back after dark to fly back east
of Houston, and "no Taxi & landing lites" - bulbs burned out.
No maintenance avail, spent the night and returned home in daylight next
day.
That airplane had a reputation for "eating" light bulbs when the wig-wag
system was used.
Would not one or the other "babying"/"pampering" design philosophies be
helpful in making those ridiculous incandescent bulbs (C-182 no have STC or
whatever for halogen bulbs and fixtures) last longer?
David Carter
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: RE: AeroElectric-List: Landing/taxi light warm up
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 10:47 AM 4/2/2003 -0500, you wrote:
> >--> AeroElectric-List message posted by: "Shannon Knoepflein"
> ><kycshann@kyol.net>
> >
> >Wouldn't it be easier on the switches and/or relays (or SSR's in my
> >case) to have these limiters to keep the current in check on circuits
> >like my 4 75W taxi/landing lights? I would think the life of the
> >contacts would improve?
>
> How big is 'improve' . . . if the rated performance of
> the switch is tens of thousands of operations with
> a resistive load and drops to, say 2,000 operations
> with a lamp load . . . how long will it take you
> to wear out the switch? If you fly twice a week
> and get 4 operations per flight, you'll get
> a calendar service life of more than 5 years.
>
> For the most part, switches in light airplanes die
> of old age and not from in-service operational
> stresses . . . no matter how you load them. I fly
> airplanes pushing 40 years old with the original,
> 10A resistive rated landing light switches humming
> right along.
>
> Keep-warm and inrush-limiting have a nice ring
> to them intellectually. I've designed inrush
> limiters for 200A a/c compressor motors that have
> 1200A inrush capabilities . . . to keep from
> bumping the bus too hard on a biz-jet . . . aside
> from this special case, I have yet to identify
> much value for incorporating this feature in
> a light aircraft. This design philosophy will be
> removed from the next revision to chapter 12.
>
> Bob . . .
>
>
Message 29
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| Subject: | Colorado Seminar Date Set |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Just got word from some folks in Englewood that they
DO wish to host a weekend seminar in Colorado . . . I'd
about given up on them, the date we'd discussed is
only 6 weeks away. However, they think we can get enough
people signed up in that time so I've posted the event
reservation at:
http://www.aeroelectric.com/seminars/Englewood.html
. . . anyone on the list interested in this program
is invited to check it out.
Bob . . .
|-------------------------------------------------------|
| The man who does not read good books has no advantage |
| over the man who cannot read them. |
| - Mark Twain |
|-------------------------------------------------------|
Message 30
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: <315@cox.net>
Okay. now I think I got it....
I didn't want to have to run more wires from the panel back to the battery
in the tail cone, but what you have shown makes sense and looks a lot safer
than what I actually have now. (BTW, This is not hypothetical but a flying
RV6A....uhm, well until that alternator OV'd last month.)
Existing now is one 'unprotected' fat wire running about 10 feet from
battery to contactor behind the panel then on to the starter and then
alternator... I don't really like having that always hot fat wire under my
arm. This needs to have a contactor like the S701-1 at the battery
location. I then need to add a battery bus next to the battery. Then I need
to add a fused lead for the ignition coils and other leads if greater than 5
or perhaps 7A would be pilot controllable contactors. (i.e. for the
essential bus if > 7A )
Okay, so I will need to add a contactor or two, a fuse block and some more
wires but it is starting to look "cleaner" in spite of the additional
wiring...
Thanks so much for taking the time to help me out,
Ned
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Mechanical Latching Battery Disconnect
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 07:24 PM 4/2/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: <315@cox.net>
> >
> >Hi Bob,
> >
> >Sorry to belabor this.
> >
> >I'm not real clear on how to do what you are suggesting...
> >
> >I thought it important to be able to isolate the battery. It is located
> >behind the occupants in the tail cone. Currently the Battery disconnect
is
> >in front of the occupants under the panel. That leaves the battery lead
> >running under one of the occupants arms. It just seemed to make sense
that
> >one should be able to cut the power from this main battery lead in the
event
> >it were to short out in the cabin.
>
> Sure . . there's a BATTERY MASTER contactor right at the
> battery. Open the battery master switch and everything
> but the battery bus goes cold. You have a battery bus right
> at the battery location too. Low current feeds (FAA likes to
> see 5A or less, I'm comfortable with 7A if fused, not breakered)
> drive directly from the battery bus. If you have higher current
> needs, then a mini-contactor, or fat-relay (like the S704 or
> it's solid state equal) is used to make feeds larger than
> 7A cold right at the bus. Your e-bus alternate feed comes
> from the battery bus, your engine dependent needs come from
> the battery bus.
>
>
> >But if this is not really that risky then it would seem that my current
> >configuration is acceptable with the disconnect contactor under the
panel.
> >I could extend the hot side of the contactor to an ignition switch that
> >would provide the battery power to the ignition. That way I could
> >de-energize the battery contactor opening all circuits except the
ignition.
> >Is this close to what you mean by your post?
>
> Battery contactors and all other controls for more than
> 5A feeders should unhook right at the battery. It would
> be best if anything larger than 5A did not venture more than
> a few inches from the battery location before it hits
> a pilot controlled disconnect.
>
> See this hypothetical:
>
> http://216.55.140.222/temp/batbus.pdf
>
> Here I show a battery bus and a battery contactor
> right next to the battery. A FAT wire comes off the
> contactor to the starter contactor and main bus.
>
> A battery bus can drive a 1A protected lead of any
> length to a clock . . .
>
> . . . a 1A protected lead to the hour-meter.
>
> . . . a 3A protected lead to a switch
> for a Kettering ignition.
>
> . . . a 7A protected lead gets a local disconnect
> relay for the e-bus alternate feed that's burdened
> with big transmitter and/or perhaps gyros. This could
> be a 10A feeder. The point is that long, always hot
> wires protected at over 5A need pilot controlled
> disconnect in close proximity to the bus.
>
> . . . if you're fuel injected and need a hi-pressure
> squirter fused at 10A, it gets a relay too.
>
> . . . a 1A courtesy light can go as far as needs
> be with no special concerns.
>
> This is what I'd have to do to sell this or a
> similar system to the FAA . . . it has to do
> with crash safety. Always hot wires from the
> battery are either pilot controllable or
> limited to 5A or less. I've seen them allow
> breakers but fuses are MUCH faster and offer
> even greater safety.
>
> We've got a lot of builders who have built
> some pretty hefty e-busses . . . with bigger
> than 5A feeders for the alternate feed path.
> If it were my airplane, I'd use the local
> disconnect relay as shown for a budget of
> about 100 mA to keep the relay closed. Or
> better yet, a solid state relay with a 10 mA
> budget.
>
> If I understand your hypothetical, you were
> going to have a LONG, FAT feeder from the
> battery coming forward to the battery contactor.
> This WOULD function but it's not recommended.
>
> Bob . . .
>
>
Message 31
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:07 AM 4/3/2003 +0900, you wrote:
>--> AeroElectric-List message posted by: "fellowsw" <fellows.w@ewcapital.net>
>
>With respect to the recommended halogen taxi/landing lights, how do they
>compare to production aircraft lights in terms of lighting ability? Do you
>measure that in terms of candlepower and angular spread at a distance? What
>are reasonable standards for illumination in terms of approach speed? Even
>the GE4509 seems to me to be much brighter at a distance than an automobile
>halogen light or the hid light.
ANYTHING halogen with the same wattage rating outperforms ANYTHING
non-halogen. The 4509 is more tightly focused. It was originally
developed for farm tractors and was picked up by the aviation
folks when they bolted the first generators on in the 40's
There's nothing magic about light output or pattern for
landing lights in the FARS until you get into flight for
hire operations. Part 23 only speaks to how an installed
light shall operate with these words:
Sec. 23.1383 Taxi and landing lights.
Each taxi and landing light must be designed and installed so that:
(a) No dangerous glare is visible to the pilots.
(b) The pilot is not seriously affected by halation.
(c) It provides enough light for night operations.
(d) It does not cause a fire hazard in any configuration.
Part 91 goes further to say that you only need to have
a landing light if you're doing flight for hire with these
words:
Sec. 91.205.c.4 If the aircraft is operated for hire, one electric landing
light.
I've had builders with the limits of 18A Rotax alternators
install a 25W flood fixture (like those used in store
window displays) in each wing tip fairing pointed down
and slightly forward. These pilots recognized that the REAL
secret to good night landings was based on what you see in
your peripheral vision either side and not on what was
1000 feet down the runway in front of you.
In short, there are dozens of opportunities to fit modern,
very robust lamps to our OBAM aircraft while our friends
in certified iron have to put up with the limitations
and expense of the tractor lamps.
>Another question, if using circuit breakers with fast on tabs, what are the
>options for mounting the tabs on a stock brass buss bar?
Can't recommend using breakers with fast-on tabs. If you want
breakers, you need to go with screw terminals to facilitate bussing
input sides of breaker rows together with strips of brass. In this
case, ring terminals are used to take the feeders out to powered
devices.
Bob . . .
Message 32
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| Subject: | Re: Landing/taxi light warm up |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:55 PM 4/2/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "David Carter"
><dcarter@datarecall.net>
>
>Bob,
>
>Before you remove the design philosophy from Chap 12, I'd like to mention
>this: I fly missions with CAP, which is gung-ho on "wig-wag" landing-taxi
>light flashing. Was no problem until leaving mission base after an all day
>search, stopped in Austin for supper, came back after dark to fly back east
>of Houston, and "no Taxi & landing lites" - bulbs burned out.
> No maintenance avail, spent the night and returned home in daylight next
>day.
>
>That airplane had a reputation for "eating" light bulbs when the wig-wag
>system was used.
>
>Would not one or the other "babying"/"pampering" design philosophies be
>helpful in making those ridiculous incandescent bulbs (C-182 no have STC or
>whatever for halogen bulbs and fixtures) last longer?
Keep-warm and/or inrush limiting doesn't help with
bulb life for wigwag ops. I did some bench testing with
several sealed beam lamps. After the initial inrush
from cold, the lamp doesn't cool off enough between
successive flashes to experience elevated inrush
for each flash.
Certified ships have crappy bulbs and they just don't
last compared to modern automotive lamps.
Bob . . .
Message 33
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| Subject: | PM Alternator run ok without battery? |
--> AeroElectric-List message posted by: <315@cox.net>
I have a John Deere supplied 20 Amp PM Dynamo and regulator and want to verify
that they will operate okay after the battery is disconnected. I plan on using
the B&C Perment Magnet Alternator Over Voltage modual with noise filter:
http://www.bandcspecialty.com/PmOVdesc.html
Since the internally regulated Denso alternator recently OV'd, I thought that perhaps
the PM would be a better full time power supply that it is supposed to
be able to run okay when the battery dies.
Any thoughts as to the best way to configure this and also to verify that it works
okay without the battery?
Thanks,
Ned
Message 34
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| Subject: | Re: Mechanical Latching Battery Disconnect |
--> AeroElectric-List message posted by: "David Carter" <dcarter@datarecall.net>
Bob,
When you say "turn off the battery master & 'lectric dependent engine should
keep running" - I would have the engine computer (ign & fuel inj) & fuel
injection pumps wired to battery bus with their own individual ON-OFF
switches. (& battery bus is the big brass bar with terminals bolted to both
sides of firewall).
-So, these two critical functions don't depend on any battery
contactor - or alternator - just at least one good battery and their own
switches getting power from the battery bus.
Is that the idea?
David Carter
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Mechanical Latching Battery Disconnect
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 02:59 PM 4/2/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: <315@cox.net>
> >
> >I have an RV6A with a Chevy V6 engine that has an ellectrically depenent
> >ignition system (coil & contacts). In the event of alternator failure I
want
> >to maximize battery life for the ignition system. The battery is in the
> >tail cone.
> Electrically dependent engine stuff should run
> directly from the battery bus.
>
> If you walk up to a J-3 and flip the mag switches
> ON, the engine is HOT and that airplane doesn't
> even have an electrical system. If that's an
> acceptable condition, why not wire your electrically
> outfitted aircraft for the same behavior?
>
> If it were my airplane, I'd like to be able to shut
> of the battery master and e-bus alternate feed any
> time there's bad smells in the cockpit WITHOUT having
> the engine stop.
>
> Bob . . .
Message 35
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| Subject: | Matronics ISP Upgrade COMPLETED! |
--> AeroElectric-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
I just wanted to send out a quick note to let everyone know that the 1.5Mb
T1 connection upgrade went smoothly today. They brought up the new line
and router yesterday on a test subnet and today the ISP switched over
connectivity about 12 noon with little to no incident. I just finished
some performance testing, and it appears that actual throughput and
interactive response is noticeably improved as advertised!
Enjoy!
Matt Dralle
Matronics Email List Admin.
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
Message 36
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| Subject: | instrument protection |
--> AeroElectric-List message posted by: Joel Harding <cajole76@ispwest.com>
I was talking to a rep from E. I. about hooking up my engine analyzer a
couple of days ago, and he mentioned that it should be isolated from
the starter circuit during start.
This may be similar to the discussion on protecting avionics from the
starter circuit, but could I get some suggestions on how best to
achieve this?
Any comments will be appreciated.
Joel Harding
Message 37
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| Subject: | Landing/taxi light warm up |
--> AeroElectric-List message posted by: "fellowsw" <fellows.w@ewcapital.net>
Bob
Thanks for your prompt reply. I don't contribute often since I am still in
the early planning stages but this my chance to say thank you very much for
your work. You are a truly amazing in terms of knowledge, appreciation of
the OBAM aircraft group and generosity with you time.
I am not concerned about meeting FAR's since mine will be OBAM. I am used to
flying at night into uncontrolled airports, in rain or snow and even
occasionally into grass strips or farm roads. I typically fly a Cessna 210
type aircraft with approximately 100 knot approach speed and 2,000 ft
landing distance. When thinking about my experience, the main concerns are
(i) short term illumination for touchdown, (ii) being able to see rain or
snow on a runway and (iii) animals on or near the runway. I was hoping to
have something like you have on fast twins which I believe is about
200,000-300,000 candlepower. My experience seems to tell me that the
lighting on a 210 is not enough but that on a fast twin is ok. I would
definitely prefer halogen to certified lamps for reliability and to hid
lights for visibility in high traffic areas. I was planning to do the
physics myself but a quick look seemed to show the 55W bulbs were well short
of this. I was hoping that someone out there had done the physics
calculations and could share them. I was also hoping to find something in 28
volts.
Best Regards
Walter Fellows
Message 38
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| Subject: | Re: to Schottky or not to Shottkey, that IS |
thw question . . .
--> AeroElectric-List message posted by: Jerzy Krasinski <krasinski@direcway.com>
Bob,
My response was not to argue with you. In fact I agree with your
position. I would even add to your arguments that a low forward voltage
drop is typical for Schottky diodes with low breakdown voltage, which
might require some sort of protection of the low voltage diode to play
it safe. That makes their use more difficult than that for a regular
rectifier diode. And for Schottky diodes with a high breakdown voltage
you find that the forward voltage drop is not much different than that
for regular junction diodes, which makes the main benefit of low forward
voltage drop questionable.
But Shannon said: "...considering Eric's diode is the only one readily
available that will handle the 20A...." I wanted to show that there
are many of such diodes around.
Jerzy
Robert L. Nuckolls, III wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>At 12:02 AM 4/2/2003 -0600, you wrote:
>
>
>>--> AeroElectric-List message posted by: Jerzy Krasinski
>><krasinski@direcway.com>
>>
>>Schottky diodes for 20A are in fact quite common, but not in Radio
>>Shack. Check www.digikey.com. Search for International Rectifier
>>Schottky rectifiers. You will find at least a hundred of different
>>Schottky diodes with max current anywhere between 20A and 400A.
>>The diodes between 20A and 40A cost roughly between $1 and $3, depending
>>on voltage . Those good for 40A to 80A cost anywhere between $3 and $10.
>>Digikey accepts telephone or email orders.
>>Jerzy
>>
>>
>
> Availability wasn't the driving consideration. I've used
> Schottky diodes for years in designs where package didn't
> particularly matter and unique performance characteristics
> were desired.
>
> The decision to recommend the bridge rectifier assembly
> came from the fact that it mounts easily as supplied . . .
> no brackets, insulating washers or solder joints required.
> They come fitted with 1/4" fast-on tabs ready to bolt to
> some handy surface between the e-bus and main-bus fuse
> blocks. No effort other than to buy it, bolt it and wire
> it. Diode arrays rated up to 35 amps in this package
> were readily available from many suppliers.
>
> Eric's product requires his manufacturing time to put
> the raw device into a user friendly package. Fine
> if you need the unique performance of the Schottky
> device. There's nothing wrong with using this
> product in your airplane . . . I'd like for
> folks to make the decision based on knowledgeable
> evaluation of fact and not upon shop-worn myths
> or marketing hype.
>
> Bob . . .
>
>
>
>
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