Today's Message Index:
----------------------
1. 12:47 AM - A413 HDA-DF strobe power supply schematics ? (Andre Beusch - Sun Switzerland Basel - Enterprise Services)
2. 01:48 AM - Status... (Matt Dralle)
3. 04:23 AM - Re: A413 HDA-DF strobe power supply schematics ? (KITFOXZ@aol.com)
4. 05:22 AM - Re: A413 HDA-DF strobe power supply schematics ? (Andre Beusch - Sun Switzerland Basel - Enterprise Services)
5. 06:57 AM - Strobe Head Wiring (Phil Birkelbach)
6. 11:55 AM - Re: Strobe Head Wiring (Robert L. Nuckolls, III)
7. 12:11 PM - Re: A413 HDA-DF strobe power supply schematics (Charlie and Tupper England)
8. 01:21 PM - LED's: Good Source (John Schroeder)
9. 02:09 PM - Re: LED's: Good Source (John Schroeder)
10. 04:35 PM - Re: Electrical System redux (Robert L. Nuckolls, III)
11. 04:38 PM - Re: Contactors, Master Switches (Robert L. Nuckolls, III)
12. 07:54 PM - Re: Master disconnect for elec trim & Autopilot (William Slaughter)
13. 10:37 PM - Re: Re: LED's: Good Source (GLikar)
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| Subject: | A413 HDA-DF strobe power supply schematics ? |
--> AeroElectric-List message posted by: Andre Beusch - Sun Switzerland Basel -
Enterprise Services <Andre.Beusch@sun.com>
I am trying to repair an old Whelen A413 HDA-DF strobe power supply.
It works for a couple of minutes then suddenly stops, no more charging of the capacitor.
I have already replaced the high voltage capacitors, but the problem persists.
I am looking for the electronics schematic drawing of this unit (or similar).
Thanks, Andre
Message 2
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--> AeroElectric-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
As promised, here's an update on this year's List Support Gift shipping
status! Wednesday 12/11 all of the CDROM-Only and all but 12 of the
CDROM+Flight Bag Gifts were shipped out via US Parcel Post. Maximum
delivery will be 8 days to the most remote areas.
For those receiving a CDROM+Flight Bag, note that the CDROM is tucked
inside one of the pouches in the Flight Bag so don't miss it!!
The remaining Flight-Bag+CDROM, Flight Bag-Only and A&P Book Sets will go
out as soon as the next shipments arrive, hopefully in the next few days.
Once again, I want to thank everyone that made a Contribution to this
year's Email List Fund Raiser! The email and web systems are now running
on brand new APC 2.2kva UPS systems thanks to the support of List members
this year. Additionally, the Email System will be upgraded later this
month with a new, Dual Processor 2.8Ghz Linux system due to arrive any
day! Your generosity has made these upgrades possible and nothing
else! Thank you so much!
Best regards,
Matt Dralle
Email List Contribution Web Site: http://www.matronics.com/contribution
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
DNA: do not archive
Message 3
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| Subject: | Re: A413 HDA-DF strobe power supply schematics ? |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
In a message dated 12/12/2002 3:47:46 AM Eastern Standard Time,
Andre.Beusch@sun.com writes:
>
> --> AeroElectric-List message posted by: Andre Beusch - Sun Switzerland
> Basel - Enterprise Services <Andre.Beusch@sun.com>
>
> I am trying to repair an old Whelen A413 HDA-DF strobe power supply.
> It works for a couple of minutes then suddenly stops, no more charging of
> the capacitor.
> I have already replaced the high voltage capacitors, but the problem
> persists.
>
> I am looking for the electronics schematic drawing of this unit (or
> similar).
>
> Thanks, Andre
>
>
Hello Andre,
I don't have a schematic handy for you to look at, but I have worked on many
circuits of this type in the past and can give you a few generic things to
look for. First, you have already replaced the most failure prone part of a
PFN (pulse forming network) like that. I assume you have done a thorough
check for bad solder joints. Reheating the joints on the board that look
suspect can often cure a sick one without even picking up your scope probe.
Does the multivibrator power transistor pair actually stop running? They are
the next pair of parts that can be replaced without looking too long for
another culprit. You need to establish whether the PFN actually stops
running and charging the capacitors or maybe the strobe circuit is not firing
due to too much resistance in the output circuit. Faulty socket connections
at the strobes etc. Do you have a buddy with the same unit that you can
borrow to look at voltage, resistance, signal comparisons at various points.
I would want to see the signal on the bases and collectors of those power
transistors.
John
Message 4
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| Subject: | Re: A413 HDA-DF strobe power supply schematics ? |
--> AeroElectric-List message posted by: Andre Beusch - Sun Switzerland Basel -
Enterprise Services <Andre.Beusch@Sun.COM>
Hello John,
thanks for these advices,
actually, after the last flash, the voltage on the high voltage capacitor stays
at zero.
There is no more charging, no sound, no current draw.
Eventually after some rest, it starts again, but for ever shorter periods.
There is a unidentified device in series with the power input which could be a
thermal switch, that
the next thing I will check.
Measurement are sort of difficult to do, there is a thick varnish all over the
PCB.
My scope is also broken, (need a scope to fix it..) and I don't have access to
another scope right
away.
So this may all take a while, my Glasair is not finished anyway.
Regards, Andre
> Subject: Re: AeroElectric-List: A413 HDA-DF strobe power supply schematics ?
> To: aeroelectric-list@matronics.com
>
> --> AeroElectric-List message posted by: KITFOXZ@aol.com
>
> In a message dated 12/12/2002 3:47:46 AM Eastern Standard Time,
> Andre.Beusch@sun.com writes:
>
> >
> > --> AeroElectric-List message posted by: Andre Beusch - Sun Switzerland
> > Basel - Enterprise Services <Andre.Beusch@sun.com>
> >
> > I am trying to repair an old Whelen A413 HDA-DF strobe power supply.
> > It works for a couple of minutes then suddenly stops, no more charging of
> > the capacitor.
> > I have already replaced the high voltage capacitors, but the problem
> > persists.
> >
> > I am looking for the electronics schematic drawing of this unit (or
> > similar).
> >
> > Thanks, Andre
> >
> >
>
> Hello Andre,
>
> I don't have a schematic handy for you to look at, but I have worked on many
> circuits of this type in the past and can give you a few generic things to
> look for. First, you have already replaced the most failure prone part of a
> PFN (pulse forming network) like that. I assume you have done a thorough
> check for bad solder joints. Reheating the joints on the board that look
> suspect can often cure a sick one without even picking up your scope probe.
> Does the multivibrator power transistor pair actually stop running? They are
> the next pair of parts that can be replaced without looking too long for
> another culprit. You need to establish whether the PFN actually stops
> running and charging the capacitors or maybe the strobe circuit is not firing
> due to too much resistance in the output circuit. Faulty socket connections
> at the strobes etc. Do you have a buddy with the same unit that you can
> borrow to look at voltage, resistance, signal comparisons at various points.
> I would want to see the signal on the bases and collectors of those power
> transistors.
>
> John
>
>
>
>
>
>
Message 5
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| Subject: | Strobe Head Wiring |
--> AeroElectric-List message posted by: "Phil Birkelbach" <phil@petrasoft.net>
I just got my strobes and power supply the other day and I have a question
about wiring up the strobe heads. I know that they are all supposed to be
hooked up with shielded wire. So my question is, do I use one three
conductor sheilded or one two conductor sheilded cable with one of the three
connections as the shield? I'm guessing one three conductor sheilded with
the shields grounded at the power supply, but I want to make sure.
Godspeed,
Phil Birkelbach
RV-7 Houston
http://www.myrv7.com
Message 6
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| Subject: | Re: Strobe Head Wiring |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:58 AM 12/12/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: "Phil Birkelbach"
><phil@petrasoft.net>
>
>I just got my strobes and power supply the other day and I have a question
>about wiring up the strobe heads. I know that they are all supposed to be
>hooked up with shielded wire. So my question is, do I use one three
>conductor sheilded or one two conductor sheilded cable with one of the three
>connections as the shield? I'm guessing one three conductor sheilded with
>the shields grounded at the power supply, but I want to make sure.
>
>Godspeed,
>Phil Birkelbach
>RV-7 Houston
>http://www.myrv7.com
No instructions with the hardware? All the kits I've seen
came with three conductor shielded wire. The strobe heads need
ground, hv and trigger lines plus a shield.
Bob . . .
Message 7
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| Subject: | Re: A413 HDA-DF strobe power supply schematics |
?
--> AeroElectric-List message posted by: Charlie and Tupper England <cengland@netdoor.com>
Andre Beusch - Sun Switzerland Basel - Enterprise Services wrote:
> --> AeroElectric-List message posted by: Andre Beusch - Sun Switzerland Basel
- Enterprise Services <Andre.Beusch@Sun.COM>
>
> Hello John,
>
> thanks for these advices,
>
> actually, after the last flash, the voltage on the high voltage capacitor stays
at zero.
> There is no more charging, no sound, no current draw.
> Eventually after some rest, it starts again, but for ever shorter periods.
>
> There is a unidentified device in series with the power input which could be
a thermal switch, that
> the next thing I will check.
>
> Measurement are sort of difficult to do, there is a thick varnish all over the
PCB.
>
> My scope is also broken, (need a scope to fix it..) and I don't have access to
another scope right
> away.
>
> So this may all take a while, my Glasair is not finished anyway.
>
>
> Regards, Andre
>
snips
>>>
Andre,
If you own a scope I may be telling you something you already know, but here's
a
'shade tree' troubleshooting technique. Actually it's only shade tree if you
must use option 2 or 3.
Use some type of cooling liquid on the various components to see if the
oscillator will restart more quickly.
Choices of coolant:
1. 'freeze spray' from an electronics supply house (hard to find due to ozone laws)
2. brake & carb cleaner in an aerosol can, if it feels very cold when sprayed
3. regular old rubbing alcohol & a q-tip swab
All the usual safety, environmental & health liability disclaimers apply here.
You obviously don't want sparks & open flame around while you do this.
Cool the entire circuit 1st & see if it will restart when cooled. If it does,
try cooling individual components (after waiting for it to shut down on its own)
to isolate the bad one. Remember that if you use too much, the coolant will cool
multiple components by cooling their leads where they attach to the circuit board.
Charlie
Message 8
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| Subject: | LED's: Good Source |
--> AeroElectric-List message posted by: John Schroeder <jschroeder@perigee.net>
Message 9
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| Subject: | Re: LED's: Good Source |
--> AeroElectric-List message posted by: John Schroeder <jschroeder@perigee.net>
Oooops! No URL - Sorry.
http://www.theledlight.com/led-assemblies.html
John
Message 10
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| Subject: | re: Electrical System redux |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Hi Bob,
Thanks for your advice. Like Columbo, just a few more questions, sir. I
think that I will go with a system similar to the one you have in your
book on Figure Z-12. I like the redundancy of 2 alternators, and with
all electric, a 20A aux alternator will power all the avionics in my
F1-Rocket (like an RV-4.) The reason I'm thinking a 20A vs the 8A unit
is that the gps/nav/com draws about 7A alone on transmit. Granted, I
don't have a lot to say, but on a dark and stormy night I think that the
extra 2 lbs will be the least of my worries. Your thoughts?
Main alternator sizing is driven by CONTINUOUS loads plus headroom
for battery charging. The standby system needs to be configured
for ENDURANCE meaning that when the main alternator is down,
you want unlimited endurance with 8-10A continuous load while holding your
battery in reserve for approach to landing. Intermittent
loads like transmit, trim, flaps, etc are insignificant to
this consideration.
Anyway, I
guess that I'm concerned about an overvoltage on the main alternator,
Easy to handle with rudimentary ov protection . . . see articles
on website and discussions in the AeroElectric Connection.
or a short on the main alt or main bus.
How is this going to happen? It's sorta like worrying about
wings falling off or propellers flying away. It's easy to
fabricate your airplane in ways that make these probabilities
too small to worry about.
In this case, the first step would
be to open the master switch. Next, close the E-bus feed, then the aux
alt switch. As you say, the order these switches are opened and closed
is important. Now, there is nothing to excite the field for the aux alt,
since it feeds from the main bus, which is now unpowered, right? What
did I miss here? Is an overvoltage or short that unlikely?
yes . . . lots of folks worry about these things based
on reading too many dark-n-stormy-night stories without
getting the benefit of critical analysis of how things
failed and what could be done to either make the system
TOLERANT of the failure.
ad the
biggest problem will be the belt breaking, or an internal failure of the
main alt resulting in the regulator not providing any field voltage to
the main alt?
. . . the most robust systems ASSUME that critical
components are going to fail to function. The system
becomes robust by deducing alternative modes of operation
wherein the failure of any single component will not
produce a situation that causes you to break a sweat.
How 'bout feeding the aux alt field off the essential bus
instead? Or even the battery bus? Further, with the battery contactor
open and a short on the main bus, should the B lead from the aux alt go
to the battery bus, or essential bus? Maybe I'm thinking too much, and
these failure modes are just too remote, but I know that just about
anything can happen in aviation.
I'm not suggesting that every kind of failure you can
imagine shouldn't be considered. They fall into three
categories (1) redesign or select alternate component to
reduce likelihood of failure [which still doesn't make
it ZERO], (2) design system and mode of operation so
that the outcome of any flight that suffers the failure
is comfortably assured or (3) failure is so remote as
to make further consideration unnecessary.
Also, I'm thinking about using a DPDT
switch for the aux alt and using the xtra set of terminals to switch the
ammeter so I don't need two ammeters--what do you think?
It would need to be a three pole switch. You need to switch
ammeter leads as pairs . . . but what you propose would work.
You show 4AWG
and 2AWG from the battery contactor to the starter contactor in different
places in your book--must be a typo. Which do you recommend--remember,
I'm cranking an IO-540?
Depends on your airplane. 2AWG is the minimum when battery and engine
are on opposite ends of airplane. On sea-planes with large
separations between engine and battery(s) wires have been
as large as 00AWG (twice the cross section of 2AWG). So,
if your battery is up front, close to firewall, 4AWG will
be fine. If your battery is behind seats, 2AWG is recommended.
Keep in mind that the power distribution diagrams are
seeds of an array of ideas for how to configure a system
for operation . . . EVERY detail of these drawings (such
as wire gage) needs to be considered in light of your
particular situation.
Thanks a lot for your help with these questions,
My pleasure . . .
PS--Really like the line in your book about vaccuum systems being for
cleaning carpets. Love to tell my buds that one. Happy Holidays.
I've had a lot of supportive response on that one . . .
Vacuum systems were marvelous inventions back in the
days when fat venturi tubes on the fuselage were
the best we could do. Remember that lots of airplanes
had gyros a decade or more before they got batteries,
starters and generators.
Like carburetors and magnetos, vacuum pumps need to
make way for better ways . . .
Bob . . .
--------------------------------------------
| People are far more willing to pay |
| for being amused than for anything else. |
| -Thomas Edison- |
--------------------------------------------
Message 11
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| Subject: | Re: Contactors, Master Switches |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Bob:
First off, thanks for all the excellent articles on your site. They're
proving extremely helpful as I put together my electrical system.
Next, a couple of questions:
Sorry to take so long to get back to you. I've been snowed
for several weeks with other tasks. I'm getting back into
the "AeroElectric" saddle . . .
1. I installed your alternator disconnect contactor for the
internally-regulated alternator. I connected the indicated ground on the
contactor terminal opposite the band on the diode. When I tested with a
12V battery, the contactor closed, but was shorted (the leads and contactor
were noticeably warm to the touch).
The whole contactor warmed up in just a few seconds?
I removed the ground lead, and the contactor still functions, independent
of polarity. What did I do wrong? Did I damage something?
The contactor itself is not polarity sensitive. It's just a coil of
wire that creates a magnetic field to close the contactor. The
contactor's mechanism doesn't care what the polarity of the
magnetic field. A contactor WILL get too hot to touch after
a few minutes. They draw about 0.8A and therefore have to dissipate
8-10 watts depending on bus voltage. If the contactor is still working,
then I'm inclined to believe it's okay.
2. I notice that you changed the master switch to an S700-2-10 switch type
from the simultaneous on and off configuration and high-lighted this with a
note. I thought the original scheme was neat, but I'm sure you've a very
good reason for the change. What is it?
Alternators generally do not run well without a battery on line. Noise
is higher, voltage stability lower and the alternator can be stalled
with momentary inrush loads from things like landing lights or landing
gear motors. The split rocker switch that appeared on light singles
in the 60's provided mechanical interlocking such that the battery
side of the switch could be ON without having the alternator on too . . .
This allows for shutting down a misbehaving alternator and
leaving the alternator off until after the engine is started. Interlocking
pins between the two halves of the switch made sure that if the
battery was taken off line, the alternator would be taken off with it.
The S700-2-10, progressive transfer switch mimics functionality
of the split rocker. One COULD consider a two pole, single throw
switch for bringing alternator and battery ON and OFF together and
using a pullable breaker (needed for crowbar ov protection system)
for disabling a misbehaving alternator . . . a rare event.
Either combination (S700-2-10) -OR- (S700-2-3 plus breaker) would
be functionally adequate. The S700-2-10 is just more elegant.
Have you considered joining us on the AeroElectric List?
Bob . . .
|-------------------------------------------------------|
| The man who does not read good books has no advantage |
| over the man who cannot read them. |
| - Mark Twain |
|-------------------------------------------------------|
Message 12
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| Subject: | Master disconnect for elec trim & Autopilot |
--> AeroElectric-List message posted by: "William Slaughter" <willslau@alumni.rice.edu>
Bob,
1)Do you consider the latching circuitry/momentary switch combination an
important element of this device? I ask because my stick grip already has
SPST push-off push-on switches installed, not momentary switches. They could
be changed out, but that's a bit of a hassle. Presuming that most OBAM
aircraft don't have any such master disconnect at all, does the latching
circuitry/momentary switch combination offer a noticeable improvement over
controlling the relay with a SPST switch?
2) My interest in the FADEC electrical architecture is not just academic -
my FADEC unit is going to be delivered in about 60 days. Unlike the Lancair
4's however, I'm building a (hopefully) lightweight night/VFR RV-8. The
"basic" FADEC plan is to have just a 7ah battery for the second FADEC power
source, but this would not comfortably run the engine for fuel duration. My
current thinking is to add the 8ah B&C alternator on the small battery
circuit (dedicated to FADEC power supply), as this is the lightest method of
gaining the desired endurance. Another choice, if more weight is needed aft,
is to forego the B&C alternator and install a second 17ah battery in the
back alongside the primary one. Looking forward to seeing your ideas on this
matter.
Thanks again.
William
-----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: Master disconnect for elec trim &
Autopilot
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 05:42 PM 12/10/2002 -0600, you wrote:
>--> AeroElectric-List message posted by: "William Slaughter"
><willslau@alumni.rice.edu>
>
>Bob,
>I really like the idea of the master disconnect for all of the electric
>items which move the control surfaces, and would like to implement it on my
>RV-8, likely using one of the switches on my stick grip. I'll have pitch
and
>roll trim, and a wing leveler autopilot. Since the switch involved will
>probably be a push-on/push-off type, an annuciator light indicating that
the
>systems were disabled might be nice. How would you suggest I go about this?
>Thanks.
Sure. See http://216.55.140.222/temp/MDRelay.gif
Message 13
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| Subject: | Re: LED's: Good Source |
--> AeroElectric-List message posted by: GLikar <glikar@shaw.ca>
Try these for plans and ideas,
http://groups.msn.com/whitelightLED/discussions.msnw .
I've converted my hiking headlamp with leds from here - $1.75 ea.
http://www.whitelightled.com/
Regards
GLL
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