Today's Message Index:
----------------------
0. 12:21 AM - November List Fund Raiser (Matt Dralle)
1. 06:12 AM - Re: Battery contactor versus circuit breaker (Noel Loveys)
2. 06:29 AM - Re: Battery contactor versus circuit breaker (Eric M. Jones)
3. 07:08 AM - Re: Z-16 (user9253)
4. 07:59 AM - Re: VOTE! (rampil)
5. 08:06 AM - Re: Re: Z-16 (Robert L. Nuckolls, III)
6. 08:37 AM - Re: Battery contactor versus circuit breaker (Robert L. Nuckolls, III)
7. 08:42 AM - Re: Re: Z-16 (Robert L. Nuckolls, III)
8. 08:48 AM - Re: Re: Z-16 (Dan Billingsley)
9. 10:08 AM - Toggle Switch Failure (reprise) (Vern Little)
10. 10:39 AM - Re: Toggle Switch Failure (reprise) (B Tomm)
11. 11:05 AM - Re: Re: Z-16 (tim2542@sbcglobal.net)
12. 11:09 AM - Re: Toggle Switch Failure (reprise) (David E. Nelson)
13. 11:51 AM - Re: Toggle Switch Failure (reprise) (Vern Little)
14. 11:51 AM - Re: Toggle Switch Failure (reprise) (Vern Little)
15. 12:07 PM - Re: Toggle Switch Failure (reprise) (tim2542@sbcglobal.net)
16. 02:09 PM - Re: AeroElectric-List Digest: 7 Msgs - 11/01/10 (Fergus Kyle)
17. 03:33 PM - Re: AeroElectric-List Digest: 7 Msgs - 11/01/10 (rparigoris)
18. 05:46 PM - Re: Re: Z-16 Diode relays (paul wilson)
19. 07:02 PM - Re: Re: Z-16 Diode relays (Tony Babb)
20. 08:45 PM - Re: Re: Z-16 Diode relays (Bob Meyers)
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Subject: | November List Fund Raiser |
There is an automatic "squelch button" of sorts for the Fund Raiser messages.
Here's how it works... As soon as a List member makes a Contribution through
the Matronics Fund Raiser web site, they will instantly cease to receive these
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Your personal Contribution matters because, when combined with other Listers such
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Message 1
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Subject: | Battery contactor versus circuit breaker |
Without seeing your schematic it sounds like the main cable coming from your
battery pack has no protection on it until it gets to the panel where the
circuit breaker is. Protection of the main battery cable is the reason that
contactors are installed as close to the battery as possible, especially in
installations where the battery is in the back of the plane. That includes
the starter solenoid and master relay.
Noel
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of mmayfield
Sent: November 2, 2010 8:27 PM
Subject: AeroElectric-List: Battery contactor versus circuit breaker
<mmayfield@ozemail.com.au>
OK, so the aircraft we're talking about has a very simple electrical system.
Day VFR only, a comm, a transponder, a few miscellaneous widgets like boost
pump, smoke pump, engine monitor, a couple of solenoid valves, and the
engine is the venerable M14P which is an air start motor. So the battery is
also correspondingly small, and recharged by the B&C SK10 alternator.
The traditional basic electrical schematic has an avionics master but I'm
discarding this because, well, I just can't see why it is needed at all for
this setup. Any issues there?
This diagram is also drawn with no battery contactor, but a main battery
circuit breaker instead, and the master switch is 14AWG wire in one side and
out the other to the bus, I believe.
How does this rate compared to using a battery contactor instead? I do
recall Bob talking of this being a bit of an unconventional layout
(regarding a B&C wiring diagram a while back). Would it be better to specify
a battery contactor in a conventional arrangement, or for this system would
it not matter too much?
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=317913#317913
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Subject: | Re: Battery contactor versus circuit breaker |
Mike,
Be aware that a battery disconnection device that can be operated with one hand
is an FAA requirement. A battery contactor is an easy way to achieve this, but
you can do it with a big switch too.
I have been recommending a race-car switch for battery disconnection. See "Flaming
River" battery switch. Similar switches can be had from Harbor Freight. Removing
the handle can offer anti-theft protection too.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=318024#318024
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Hi Dan,
I am not familiar with the S704-1 relay. But since nobody else answered, I will
give it a shot. Polarity of the coil does not matter for most relays. If a
relay has a built in diode, then polarity will matter. You could test the coil
with an ohmmeter to see if the coil is short circuited with one polarity and
not the other. Or you could put a small lamp in series with the relay. If
the lamp gets brighter with one polarity compared to the opposite polarity, then
there is a built in diode and the correct polarity is when the lamp is dim.
Or you could power up the relay using a power supply with built in short circuit
protection and see what happens. Or you could call B&C and ask them.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=318027#318027
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Major Daley (the elder) said: Vote Early, Vote Often!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=318033#318033
Message 5
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At 09:05 AM 11/3/2010, you wrote:
>
>Hi Dan,
>I am not familiar with the S704-1 relay. But since nobody else
>answered, I will give it a shot. Polarity of the coil does not
>matter for most relays. If a relay has a built in diode, then
>polarity will matter. You could test the coil with an ohmmeter to
>see if the coil is short circuited with one polarity and not the
>other. Or you could put a small lamp in series with the relay. If
>the lamp gets brighter with one polarity compared to the opposite
>polarity, then there is a built in diode and the correct polarity is
>when the lamp is dim. Or you could power up the relay using a power
>supply with built in short circuit protection and see what
>happens. Or you could call B&C and ask them.
Good put. I'm aware of no commercial-off-the-shelf relays
with built in diodes and only a few contactors with such
devices already installed. If they DO feature internally
wired diodes, the coil terminal polarity will be marked
and the device will probably have some symbolism or
text notification of the feature.
The "S704" is a catalog number for a "T91" style
SPDT relay first defined by Potter-Brumfield as
I recall . . . and later 'cloned' by many others
as popularity of this device soared.
Emacs!
But it's nothing special. Any 12v, 30A, DPDT
relay will do the same job . . . including
this device from Radio Shack
Emacs!
Catalog #275-226. Many of the BigBox auto parts
stores sell similar devices in peg-racked blister-
paks. It might be called a "headlight relay".
But its a sure bet than none will feature built
in diodes. Here's an exemplar part from the
AutoZone website:
http://tinyurl.com/24gobxs
Interestingly enough, AutoZone stocks a pre-terminated
diode assembly that can be added to this or similar
relays:
http://tinyurl.com/2cqrk4q
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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Subject: | Battery contactor versus circuit breaker |
At 08:08 AM 11/3/2010, you wrote:
Without seeing your schematic it sounds like the main cable coming from your
battery pack has no protection on it until it gets to the panel where the
circuit breaker is. Protection of the main battery cable is the reason that
contactors are installed as close to the battery as possible, especially in
installations where the battery is in the back of the plane. That includes
the starter solenoid and master relay.
I'll offer the following expansion of the idea behind
local battery disconnect. It's not so much for "protection"
of any wires as for reduction in probability of post-crash
fire. A powered up electrical system could warm up your
day considerably without damaging a single wire.
A engineer friend of mine at Hawker-Beech used to investigate
accidents involving our products. He once shared an anecdotal
observation suggesting that if the airplane caught fire
after the crash, the battery was most likely still in the
airframe. If it didn't burn, he expected to find the battery
tossed into the woods somewhere.
Obviously not scientific but a valid recognition of the
energy that can be released when a battery is discharged
into the bent-metal products of a crash. Having a pre-crash
procedure that isolates the battery from as much of ship's
wiring as practical goes a long way toward reducing after-crash
hazard.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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> Interestingly enough, AutoZone stocks a pre-terminated
> diode assembly that can be added to this or similar
> relays:
>
>http://tinyurl.com/2cqrk4q
Whew!!!! just noted that this part sells for
about $10. Go get your own 1N5402, 75-cent
critters from R-S . . .
Emacs!
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 8
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Joe and Bob,
Thank you for your reply...I found it interesting that the relay had little to
no markings. It came with a sheet that identified a couple of contacts, yet left
the coil to one's imagination. This led me to believe that polarity is not an
issue. Again, thanks Joe for the reply and practicle things to try to make
determinations.
Best wishes, Dan
----- Original Message ----
From: user9253 <fran4sew@banyanol.com>
Sent: Wed, November 3, 2010 7:05:41 AM
Subject: AeroElectric-List: Re: Z-16
Hi Dan,
I am not familiar with the S704-1 relay. But since nobody else answered, I will
give it a shot. Polarity of the coil does not matter for most relays. If a
relay has a built in diode, then polarity will matter. You could test the coil
with an ohmmeter to see if the coil is short circuited with one polarity and not
the other. Or you could put a small lamp in series with the relay. If the lamp
gets brighter with one polarity compared to the opposite polarity, then there is
a built in diode and the correct polarity is when the lamp is dim. Or you could
power up the relay using a power supply with built in short circuit protection
and see what happens. Or you could call B&C and ask them.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=318027#318027
Message 9
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Subject: | Toggle Switch Failure (reprise) |
My (final) conclusion on toggle switch failures in my RV-9A.
In a recent Transport Canada Aviation Safety Letter, there is an article
that is relevant to the long debate we had a few years ago about the
failure of toggle switches (specifically Carling brand) in the strobe,
landing and taxi light circuits of our aircraft.
The article is here:
http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
The summary is this: Cessna has issued a mandatory service bulletin to
replace all subject switches used in the landing light as well as the
taxi light and rotating beacon circuits in the 100-, 200- and 300-
series. The FAA issued an SAIB to this effect.
The root cause is that the switches used were not suitable to the
applications. Surge currents are many times (8x) the nominal currents
for lighting loads, well outside the switch ratings. Also, the switches
used did not have DC ratings.
During the aeroelectric debate and Bob`s research of the Carling switch
failures, we found evidence of manufacturing problems, however,
overstressing the switches may be in fact the causal link in the failure
chain. I used inrush current limiters on my landing light circuits
which helps. My strobe switches did not use the limiters and failed
just short of a smoke/fire incident. These switches have no specific DC
rating, although common use is to follow the 115VAC rated current.
Therefore, my next aircraft (HR-II) is not using switches to carry heavy
loads. Instead, it will be using DC-rated relays (with up to 70A DC
rating for resistive loads). These should be adequate for most loads.
The relays are controlled with low-current switches (with gold/silver
contacts).
Thanks,
Vern
Message 10
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Subject: | Toggle Switch Failure (reprise) |
Thanks for the follow-up on this issue Vern. I am just now preparing to
install toggle switches and also have the Carlings. I am planning to use
relays for the heavy loads but now am wondering if the 20 amp relays that B
and C sells will be up to the task, (if in fact inrush is 8X as you say).
Would the inrush limiters limit it to say 2X or less and if so where does
one buy them?
Bevan
Abbotsford
RV7A wiring
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Vern
Little
Sent: Wednesday, November 03, 2010 10:04 AM
Subject: AeroElectric-List: Toggle Switch Failure (reprise)
My (final) conclusion on toggle switch failures in my RV-9A.
In a recent Transport Canada Aviation Safety Letter, there is an article
that is relevant to the long debate we had a few years ago about the failure
of toggle switches (specifically Carling brand) in the strobe, landing and
taxi light circuits of our aircraft.
The article is here:
http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
The summary is this: Cessna has issued a mandatory service bulletin to
replace all subject switches used in the landing light as well as the taxi
light and rotating beacon circuits in the 100-, 200- and 300- series. The
FAA issued an SAIB to this effect.
The root cause is that the switches used were not suitable to the
applications. Surge currents are many times (8x) the nominal currents for
lighting loads, well outside the switch ratings. Also, the switches used
did not have DC ratings.
During the aeroelectric debate and Bob`s research of the Carling switch
failures, we found evidence of manufacturing problems, however,
overstressing the switches may be in fact the causal link in the failure
chain. I used inrush current limiters on my landing light circuits which
helps. My strobe switches did not use the limiters and failed just short of
a smoke/fire incident. These switches have no specific DC rating, although
common use is to follow the 115VAC rated current.
Therefore, my next aircraft (HR-II) is not using switches to carry heavy
loads. Instead, it will be using DC-rated relays (with up to 70A DC rating
for resistive loads). These should be adequate for most loads. The relays
are controlled with low-current switches (with gold/silver contacts).
Thanks,
Vern
Message 11
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I bought relays from NAPA, no diode but they do have resistors in the coil c
ircuit. I don't have the part number with me but can get it.
Tim Andres
Sent from my iPhone
On Nov 3, 2010, at 8:04 AM, "Robert L. Nuckolls, III" <nuckolls.bob@aeroelec
tric.com> wrote:
> At 09:05 AM 11/3/2010, you wrote:
m>
>>
>> Hi Dan,
>> I am not familiar with the S704-1 relay. But since nobody else answered,
I will give it a shot. Polarity of the coil does not matter for most relay
s. If a relay has a built in diode, then polarity will matter. You could t
est the coil with an ohmmeter to see if the coil is short circuited with one
polarity and not the other. Or you could put a small lamp in series with t
he relay. If the lamp gets brighter with one polarity compared to the oppos
ite polarity, then there is a built in diode and the correct polarity is whe
n the lamp is dim. Or you could power up the relay using a power supply wit
h built in short circuit protection and see what happens. Or you could call
B&C and ask them.
>
> Good put. I'm aware of no commercial-off-the-shelf relays
> with built in diodes and only a few contactors with such
> devices already installed. If they DO feature internally
> wired diodes, the coil terminal polarity will be marked
> and the device will probably have some symbolism or
> text notification of the feature.
>
> The "S704" is a catalog number for a "T91" style
> SPDT relay first defined by Potter-Brumfield as
> I recall . . . and later 'cloned' by many others
> as popularity of this device soared.
>
> <263881f.jpg>
>
> But it's nothing special. Any 12v, 30A, DPDT
> relay will do the same job . . . including
> this device from Radio Shack
>
> <263887d.jpg>
>
> Catalog #275-226. Many of the BigBox auto parts
> stores sell similar devices in peg-racked blister-
> paks. It might be called a "headlight relay".
> But its a sure bet than none will feature built
> in diodes. Here's an exemplar part from the
> AutoZone website:
>
> http://tinyurl.com/24gobxs
>
> Interestingly enough, AutoZone stocks a pre-terminated
> diode assembly that can be added to this or similar
> relays:
>
> http://tinyurl.com/2cqrk4q
>
>
>
> Bob . . .
>
> ---------------------------------------
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ---------------------------------------
>
Message 12
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Subject: | Re: Toggle Switch Failure (reprise) |
Hi Vern,
I was just thinking about this thread the other week while hooking up my strobe
power-supply. The unit is a Nova XPAK-604 (IIRC) and I noticed that in the
supplied wiring diagram that they tied the supply lead to the power source w/o
any switches. The unit's operation is then turned on/off by a control signal
via a small guage wire.
I don't recall anybody else mentioning this so I'm bringing it up because I
think it may offer a viable alternative for others that are using this unit.
The install guide is here:
http://www.strobesnmore.com/nova-x-pak-strobe-power-supplies.html
Regards,
/\/elson
~~ Lately my memory seems to be like a steel trap .... without any spring. ~~
On Wed, 3 Nov 2010, Vern Little wrote:
> My (final) conclusion on toggle switch failures in my RV-9A.
>
> In a recent Transport Canada Aviation Safety Letter, there is an article that
is relevant to the long debate we had a few years ago about the failure of toggle
switches (specifically Carling
> brand) in the strobe, landing and taxi light circuits of our aircraft.
>
> The article is here: http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
>
> The summary is this: Cessna has issued a mandatory service bulletin to replace
all subject switches used in the landing light as well as the taxi light and
rotating beacon circuits in the
> 100-, 200- and 300- series. The FAA issued an SAIB to this effect.
>
> The root cause is that the switches used were not suitable to the applications.
Surge currents are many times (8x) the nominal currents for lighting loads,
well outside the switch ratings.
> Also, the switches used did not have DC ratings.
>
> During the aeroelectric debate and Bob`s research of the Carling switch failures,
we found evidence of manufacturing problems, however, overstressing the switches
may be in fact the causal
> link in the failure chain. I used inrush current limiters on my landing light
circuits which helps. My strobe switches did not use the limiters and failed
just short of a smoke/fire
> incident. These switches have no specific DC rating, although common use is
to follow the 115VAC rated current.
>
> Therefore, my next aircraft (HR-II) is not using switches to carry heavy loads.
Instead, it will be using DC-rated relays (with up to 70A DC rating for resistive
loads). These should be
> adequate for most loads. The relays are controlled with low-current switches
(with gold/silver contacts).
>
> Thanks,
> Vern
Message 13
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Subject: | Re: Toggle Switch Failure (reprise) |
Relays are cheap, even the 70A ones. They are mostly pin-compatible
with the lower-rated ones.
Both the relays and the limiters are available at Digikey. Search
"automotive relay" and "inrush current limiter".
I tend to use parts from Digikey, even if available at the local Tire
and Hockey shop because of the traceability and datasheet availability.
Vern
From: B Tomm
Sent: Wednesday, November 03, 2010 10:36 AM
Subject: RE: AeroElectric-List: Toggle Switch Failure (reprise)
Thanks for the follow-up on this issue Vern. I am just now preparing to
install toggle switches and also have the Carlings. I am planning to
use relays for the heavy loads but now am wondering if the 20 amp relays
that B and C sells will be up to the task, (if in fact inrush is 8X as
you say). Would the inrush limiters limit it to say 2X or less and if
so where does one buy them?
Bevan
Abbotsford
RV7A wiring
-------------------------------------------------------------------------
-------
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Vern
Little
Sent: Wednesday, November 03, 2010 10:04 AM
Subject: AeroElectric-List: Toggle Switch Failure (reprise)
My (final) conclusion on toggle switch failures in my RV-9A.
In a recent Transport Canada Aviation Safety Letter, there is an article
that is relevant to the long debate we had a few years ago about the
failure of toggle switches (specifically Carling brand) in the strobe,
landing and taxi light circuits of our aircraft.
The article is here:
http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
The summary is this: Cessna has issued a mandatory service bulletin to
replace all subject switches used in the landing light as well as the
taxi light and rotating beacon circuits in the 100-, 200- and 300-
series. The FAA issued an SAIB to this effect.
The root cause is that the switches used were not suitable to the
applications. Surge currents are many times (8x) the nominal currents
for lighting loads, well outside the switch ratings. Also, the switches
used did not have DC ratings.
During the aeroelectric debate and Bob`s research of the Carling switch
failures, we found evidence of manufacturing problems, however,
overstressing the switches may be in fact the causal link in the failure
chain. I used inrush current limiters on my landing light circuits
which helps. My strobe switches did not use the limiters and failed
just short of a smoke/fire incident. These switches have no specific DC
rating, although common use is to follow the 115VAC rated current.
Therefore, my next aircraft (HR-II) is not using switches to carry heavy
loads. Instead, it will be using DC-rated relays (with up to 70A DC
rating for resistive loads). These should be adequate for most loads.
The relays are controlled with low-current switches (with gold/silver
contacts).
Thanks,
Vern
href="http://www.aeroelectric.com">www.aeroelectric.com
href="http://www.buildersbooks.com">www.buildersbooks.com
href="http://www.homebuilthelp.com">www.homebuilthelp.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.
matronics.com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
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Subject: | Re: Toggle Switch Failure (reprise) |
Thanks for the information. It seems that this is a viable alternative
although I hate being able to shut down a power source in the event of a
fire. A pullable breaker would be a good answer to that.
Vern
--------------------------------------------------
From: "David E. Nelson" <david.nelson@pobox.com>
Sent: Wednesday, November 03, 2010 11:05 AM
Subject: Re: AeroElectric-List: Toggle Switch Failure (reprise)
> <david.nelson@pobox.com>
>
>
> Hi Vern,
>
> I was just thinking about this thread the other week while hooking up my
> strobe
> power-supply. The unit is a Nova XPAK-604 (IIRC) and I noticed that in
> the
> supplied wiring diagram that they tied the supply lead to the power source
> w/o
> any switches. The unit's operation is then turned on/off by a control
> signal
> via a small guage wire.
>
> I don't recall anybody else mentioning this so I'm bringing it up because
> I
> think it may offer a viable alternative for others that are using this
> unit.
>
> The install guide is here:
>
> http://www.strobesnmore.com/nova-x-pak-strobe-power-supplies.html
>
> Regards,
> /\/elson
>
>
> ~~ Lately my memory seems to be like a steel trap .... without any
> spring. ~~
>
> On Wed, 3 Nov 2010, Vern Little wrote:
>
>> My (final) conclusion on toggle switch failures in my RV-9A.
>>
>> In a recent Transport Canada Aviation Safety Letter, there is an article
>> that is relevant to the long debate we had a few years ago about the
>> failure of toggle switches (specifically Carling
>> brand) in the strobe, landing and taxi light circuits of our aircraft.
>>
>> The article is here:
>> http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
>>
>> The summary is this: Cessna has issued a mandatory service bulletin to
>> replace all subject switches used in the landing light as well as the
>> taxi light and rotating beacon circuits in the
>> 100-, 200- and 300- series. The FAA issued an SAIB to this effect.
>>
>> The root cause is that the switches used were not suitable to the
>> applications. Surge currents are many times (8x) the nominal currents
>> for lighting loads, well outside the switch ratings.
>> Also, the switches used did not have DC ratings.
>>
>> During the aeroelectric debate and Bob`s research of the Carling switch
>> failures, we found evidence of manufacturing problems, however,
>> overstressing the switches may be in fact the causal
>> link in the failure chain. I used inrush current limiters on my landing
>> light circuits which helps. My strobe switches did not use the limiters
>> and failed just short of a smoke/fire
>> incident. These switches have no specific DC rating, although common use
>> is to follow the 115VAC rated current.
>>
>> Therefore, my next aircraft (HR-II) is not using switches to carry heavy
>> loads. Instead, it will be using DC-rated relays (with up to 70A DC
>> rating for resistive loads). These should be
>> adequate for most loads. The relays are controlled with low-current
>> switches (with gold/silver contacts).
>>
>> Thanks,
>> Vern
>
>
>
> Checked by AVG - www.avg.com
> 08:36:00
>
Message 15
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Subject: | Re: Toggle Switch Failure (reprise) |
Just did this last week myself! If you note they still require 18AWG wire as as
minimum for the control lead, which made me think it must have some current on
it. I used a relay to avoid having both leads go all the way forward and then
back.
Tim Andres
Sent from my iPhone
On Nov 3, 2010, at 11:05 AM, "David E. Nelson" <david.nelson@pobox.com> wrote:
>
>
> Hi Vern,
>
> I was just thinking about this thread the other week while hooking up my strobe
power-supply. The unit is a Nova XPAK-604 (IIRC) and I noticed that in the
supplied wiring diagram that they tied the supply lead to the power source w/o
any switches. The unit's operation is then turned on/off by a control signal
via a small guage wire.
>
> I don't recall anybody else mentioning this so I'm bringing it up because I think
it may offer a viable alternative for others that are using this unit.
>
> The install guide is here:
>
> http://www.strobesnmore.com/nova-x-pak-strobe-power-supplies.html
>
> Regards,
> /\/elson
>
>
> ~~ Lately my memory seems to be like a steel trap .... without any spring.
~~
>
> On Wed, 3 Nov 2010, Vern Little wrote:
>
>> My (final) conclusion on toggle switch failures in my RV-9A.
>> In a recent Transport Canada Aviation Safety Letter, there is an article that
is relevant to the long debate we had a few years ago about the failure of toggle
switches (specifically Carling
>> brand) in the strobe, landing and taxi light circuits of our aircraft.
>> The article is here: http://www.tc.gc.ca/media/documents/ca-publications/tp185e_4_2010.pdf
>> The summary is this: Cessna has issued a mandatory service bulletin to replace
all subject switches used in the landing light as well as the taxi light and
rotating beacon circuits in the
>> 100-, 200- and 300- series. The FAA issued an SAIB to this effect.
>> The root cause is that the switches used were not suitable to the applications.
Surge currents are many times (8x) the nominal currents for lighting loads,
well outside the switch ratings. Also, the switches used did not have DC ratings.
>> During the aeroelectric debate and Bob`s research of the Carling switch failures,
we found evidence of manufacturing problems, however, overstressing the
switches may be in fact the causal
>> link in the failure chain. I used inrush current limiters on my landing light
circuits which helps. My strobe switches did not use the limiters and failed
just short of a smoke/fire
>> incident. These switches have no specific DC rating, although common use is
to follow the 115VAC rated current.
>> Therefore, my next aircraft (HR-II) is not using switches to carry heavy loads.
Instead, it will be using DC-rated relays (with up to 70A DC rating for
resistive loads). These should be
>> adequate for most loads. The relays are controlled with low-current switches
(with gold/silver contacts).
>> Thanks,
>> Vern
>
>
>
>
Message 16
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Subject: | RE: AeroElectric-List Digest: 7 Msgs - 11/01/10 |
Time: 03:50:43 PM PST US
Subject: AeroElectric-List: LED strips for cabin light
From: James Kilford <james@etravel.org>
Gents,
I've been pondering for a while what to do about an inexpensive,
neat
cabin light for my Jodel project. I thought LEDs were the way to go,
and instead of fabricating something, bought something like this:
http://cgi.ebay.co.uk/24-LED-White-Flexible-Strip-Waterproof-Car-Light-Bulb-
/160500858701#ht_3067wt_1066
It runs straight off the bus, is nice and bright, and was easy
enough
to mount. It's set into a slot in a piece of thin ply, with some
spruce stiffeners each side of the slot, then the ply was covered with
headlining material. It fits really well in the cabin roof. Picture
attached. Forgive the poor quality, but hopefully you can make out
what's going on.
James
James:
My only question is : What the current draw for my poor old Ducati?
No one ever seems to say.....
Cheers
Ferg
Message 17
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Subject: | Re: AeroElectric-List Digest: 7 Msgs - 11/01/10 |
Hi Ferg
"My only question is : What the current draw for my poor old Ducati?
No one ever seems to say....."
Someone gave me a partial string of LEDs in white that looks similar to what you
referenced. I have been mutilating the sealed string to retrieve the individual
LEDs that seem to be about the right color temp, size and brightness for several
panel lighting applications.
Anyway the ones I have have 3 LEDs in series with a resistor (intended to run
off of 12 volts). The 3 series LEDs draw 19 mAs when running off my Odyssey 545.
Thus on my string 24 would be drawing 152mAs or .152 amps. I fooled with bumping
up to 20, 25, 30 and 35 mAs, not much of an increase in brightness.
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=318081#318081
Message 18
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Subject: | Re: Z-16 Diode relays |
Bob, mid 90s vintage Ford relays all have the internal diode. When
getting a replacement at the auto store I just look at the diagram on
the thing. Most of the time they try to sell me the cheaper one with
no diode. Then I just ask for the more expensive one and shure enough
they always have the diode. There are 4 or 5 of them and they are all
the same part number. NAPA is a good source, but not RS. They are the
traditional 30a things just like we are all famiuliar with and fit a
1/4" female faston.
Comfort is having spares
Paul
Message 19
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Subject: | Re: Z-16 Diode relays |
I know the answer must be blindingly obvous but it escapes me. Why have a
diode in the first place, doesn't the relay close regardless of which way
the current is flowing?
Tony
Velocity SEFG 62% done, 78% to go
www.alejandra.net/velocity
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of paul
wilson
Sent: Wednesday, November 03, 2010 5:20 PM
Subject: Re: AeroElectric-List: Re: Z-16 Diode relays
Bob, mid 90s vintage Ford relays all have the internal diode. When
getting a replacement at the auto store I just look at the diagram on
the thing. Most of the time they try to sell me the cheaper one with
no diode. Then I just ask for the more expensive one and shure enough
they always have the diode. There are 4 or 5 of them and they are all
the same part number. NAPA is a good source, but not RS. They are the
traditional 30a things just like we are all famiuliar with and fit a
1/4" female faston.
Comfort is having spares
Paul
Message 20
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Subject: | Re: Z-16 Diode relays |
Voltage spike suppression.
Bob posted a document a few weeks ago about the how and why of spike
suppression. Here is the link.
http://tinyurl.com/25wjo7w
Bob Meyers
Flight Testing Sonex N982SX Web Site Index http://N982SX.com
On Nov 3, 2010, at 8:58 PM, Tony Babb wrote:
> >
>
> I know the answer must be blindingly obvous but it escapes me. Why
> have a
> diode in the first place, doesn't the relay close regardless of
> which way
> the current is flowing?
>
> Tony
> Velocity SEFG 62% done, 78% to go
> www.alejandra.net/velocity
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> paul
> wilson
> Sent: Wednesday, November 03, 2010 5:20 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Re: Z-16 Diode relays
>
>
>
> Bob, mid 90s vintage Ford relays all have the internal diode. When
> getting a replacement at the auto store I just look at the diagram on
> the thing. Most of the time they try to sell me the cheaper one with
> no diode. Then I just ask for the more expensive one and shure enough
> they always have the diode. There are 4 or 5 of them and they are all
> the same part number. NAPA is a good source, but not RS. They are the
> traditional 30a things just like we are all famiuliar with and fit a
> 1/4" female faston.
> Comfort is having spares
>
> Paul
>
>
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