Today's Message Index:
----------------------
1. 01:38 AM - Re: Must strobe feed wires be shielded? (Cy Galley)
2. 05:07 AM - Re: Must strobe feed wires be shielded? (Jon Finley)
3. 05:37 AM - Re: Must strobe feed wires be shielded? (rondefly)
4. 06:46 AM - Re: Z-14 Interface with FADEC (Robert L. Nuckolls, III)
5. 06:46 AM - Re: Must strobe feed wires be shielded? (Shannon Knoepflein)
6. 06:49 AM - AutoE-bus'Witch (Eric M. Jones)
7. 06:52 AM - Re: Must strobe feed wires be shielded? (Robert L. Nuckolls, III)
8. 06:55 AM - Crowbar OVM (Eric M. Jones)
9. 07:10 AM - Re: Must strobe feed wires be shielded? (BobsV35B@aol.com)
10. 07:48 AM - Re: Must strobe feed wires be shielded? (Shannon Knoepflein)
11. 09:56 AM - Re: DRE-244e Intercom wiring (James E. Clark)
12. 10:02 AM - Instrument Panel Lights (Julia)
13. 10:28 AM - Fluxuating Amp meter (Terry Lamp)
14. 11:04 AM - Re: Fluxuating Amp meter (Rhett Westerman)
15. 02:08 PM - Re: Instrument Panel Lights (Julia)
16. 02:17 PM - Re: Instrument Panel Lights (Julia)
17. 03:47 PM - Harware locations versus noise. (Robert L. Nuckolls, III)
18. 04:37 PM - Re: Re: E.I. instruments need pampering? (Rino)
19. 05:00 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger)
20. 05:53 PM - Re: Re: E.I. instruments need pampering? (Matt Prather)
21. 07:28 PM - Re: Re: E.I. instruments need pampering? (Cy Galley)
22. 07:52 PM - Re: Re: E.I. instruments need pampering? (Robert L. Nuckolls, III)
23. 07:54 PM - Re: Re: E.I. instruments need pampering? (Robert L. Nuckolls, III)
24. 08:26 PM - Approach-Systems Avionics Wiring System (DeWitt (Dee) Whittington)
25. 08:34 PM - Re: Must strobe feed wires be shielded? (BobsV35B@aol.com)
26. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger)
27. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger)
28. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger)
29. 09:05 PM - THANK YOU BOB! YOU ARE PROVIDING A GREAT SERVICE (Paul Messinger)
30. 09:22 PM - Re: Must strobe feed wires be shielded? (Richard E. Tasker)
31. 09:23 PM - Re: Re: E.I. instruments need pampering? (Robert McCallum)
32. 10:37 PM - FS: MX20 (richard@riley.net)
Message 1
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| Subject: | Re: Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Cy Galley" <cgalley@qcbc.org>
Go to an electrician and get some wire pulling lube. Chamfer the tube
opening and have a go at it with all the wires at once. You can use the tube
as the ground wire if cleaned, using Aluminum wire connection compound and
appropriate clamps.
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cgalley@qcbc.org or experimenter@eaa.org
Always looking for articles for the Experimenter
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 11:14 PM 4/7/2003 -0500, you wrote:
> >--> AeroElectric-List message posted by: "Sam Hoskins"
> ><shoskins@globaleyes.net>
> >
> >Thanks for the prompt reply, Bob.
> >
> >The problem is, I'm running wire for the strobe and the position lights
> >through a narrow (3/8" I.D.?) piece of tubing that runs down through my
> >composite wing. I installed this tube 15 years ago when I built the wing
> >and there is no practical way to enlarge it. I hope to squeeze all the
> >wires through this opening. My reasoning is that I could run 5 pieces of
> >18AWG more easily than a cable and the two for the position lights.
> >
> >Sam
>
> Understand . . . no magic wands I can wave here
> and make it okay and I've never had the chance
> to try it myself. You're charting new territory.
> Hope it works okay.
>
> Bob . . .
>
>
Message 2
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| Subject: | Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
Is it possible for Sam to use one wire for each strobe using the center
conductor for positive current and the shield for the negative (Instead
of two wires - one for positive and one for ground)?? Could the same
thing be done for the position light?
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 440 Hrs. TT - 0 Hrs Engine
Apple Valley, Minnesota
http://www.FinleyWeb.net/default.asp?id=96
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On
> Behalf Of Sam Hoskins
> Sent: Monday, April 07, 2003 11:15 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
>
>
> --> AeroElectric-List message posted by: "Sam Hoskins"
> --> <shoskins@globaleyes.net>
>
> Thanks for the prompt reply, Bob.
>
> The problem is, I'm running wire for the strobe and the
> position lights through a narrow (3/8" I.D.?) piece of tubing
> that runs down through my composite wing. I installed this
> tube 15 years ago when I built the wing and there is no
> practical way to enlarge it. I hope to squeeze all the wires
> through this opening. My reasoning is that I could run 5
> pieces of 18AWG more easily than a cable and the two for the
> position lights.
>
> Sam
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
>
>
> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
> >
> > At 09:11 PM 4/7/2003 -0500, you wrote:
> > >--> AeroElectric-List message posted by: "Sam Hoskins"
> > ><shoskins@globaleyes.net>
> > >
> > >Must strobe feed wires be shielded? I am cobbling
> together a strobe
> system,
> > >using Whelen lights and I intend to buy one of those power
> supplies
> > >from strobes-r-us.com. I wish to mount the PS somewhere in the
> > >center
> section.
> > >
> > >Can I just run regular 18AWG wire from the PS to the wing tips?
> >
> >
> > These wired DO carry fast-risetime voltage and current pulses
> > that are worthy of shields and the twisted-trio configuration
> > supplied with a contemporary strobe installation kit.
> >
> > Why would you NOT want to shield it? The wire isn't expensive.
> > But then, you could give it a try. The outcome cannot
> be anything
> > worse than having to replace the wire later.
> >
> >
> > Bob . . .
> >
Message 3
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| Subject: | Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "rondefly" <rondefly@pacbell.net>
My question to Jon's suggestion would be, If you go that way why use
shielded at all. Wouldn't you be taking away the shield by having it be part
of the conductor? You can get shelding by itself and just put it where it
will interfere with other circuits and use 18AWG to fit in the tubing.
Ron Triano Quicker one Q-200, 90% Done with 90% to go
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Jon
Finley
Subject: RE: AeroElectric-List: Must strobe feed wires be shielded?
--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
Is it possible for Sam to use one wire for each strobe using the center
conductor for positive current and the shield for the negative (Instead
of two wires - one for positive and one for ground)?? Could the same
thing be done for the position light?
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 440 Hrs. TT - 0 Hrs Engine
Apple Valley, Minnesota
http://www.FinleyWeb.net/default.asp?id=96
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On
> Behalf Of Sam Hoskins
> Sent: Monday, April 07, 2003 11:15 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
>
>
> --> AeroElectric-List message posted by: "Sam Hoskins"
> --> <shoskins@globaleyes.net>
>
> Thanks for the prompt reply, Bob.
>
> The problem is, I'm running wire for the strobe and the
> position lights through a narrow (3/8" I.D.?) piece of tubing
> that runs down through my composite wing. I installed this
> tube 15 years ago when I built the wing and there is no
> practical way to enlarge it. I hope to squeeze all the wires
> through this opening. My reasoning is that I could run 5
> pieces of 18AWG more easily than a cable and the two for the
> position lights.
>
> Sam
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
>
>
> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <bob.nuckolls@cox.net>
> >
> > At 09:11 PM 4/7/2003 -0500, you wrote:
> > >--> AeroElectric-List message posted by: "Sam Hoskins"
> > ><shoskins@globaleyes.net>
> > >
> > >Must strobe feed wires be shielded? I am cobbling
> together a strobe
> system,
> > >using Whelen lights and I intend to buy one of those power
> supplies
> > >from strobes-r-us.com. I wish to mount the PS somewhere in the
> > >center
> section.
> > >
> > >Can I just run regular 18AWG wire from the PS to the wing tips?
> >
> >
> > These wired DO carry fast-risetime voltage and current pulses
> > that are worthy of shields and the twisted-trio configuration
> > supplied with a contemporary strobe installation kit.
> >
> > Why would you NOT want to shield it? The wire isn't expensive.
> > But then, you could give it a try. The outcome cannot
> be anything
> > worse than having to replace the wire later.
> >
> >
> > Bob . . .
> >
Message 4
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| Subject: | Z-14 Interface with FADEC |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:49 PM 4/7/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: "Tom Schiff" <tomschiff@attbi.com>
>
>I recently read a article in a Motorcycle magazine that related the
>troubleshooting of a Honda Gold Wing 1800 (a recent model). The owner
>was on a long cross country trip and stopped for lunch. When he returned
>the starter would spin the motor but it wouldn't start. Two Honda
>dealerships, much conferring with Honda, and many thousands of dollars
>of troubleshooting later the bike would still not start. The editor of
>the magazine was called in to see if he could help. I brought a new
>battery with him and a volt meter. He determined that when the starter
>was cranking the original battery voltage would drop below 10 volts. He
>installed the new battery and the bike roared to life. Is this what the
>FADEC's are going to bring to the aviation world?
Only when the designers don't understand the world in which
they propose to sell product. When consumers buy their
products anyhow and quietly work around the shortcomings,
there will be no pressure to change . . . Folks who make
the "rules" don't understand the world they make rules
about either so we can't look for help there. It's
up to the knowledgeable consumer to vote with their
checkbook and communicate good critical review by means of
their choice.
Bob . . .
Message 5
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| Subject: | Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
Since we are on the strobe kick again, I never have convinced myself
that 18 gauge is necasarry with the Whelen strobes. 22 certainly would
be easier for Sam to run in his small tube. It seems Old Bob has run 22
with success.
If they have 21J of energy, which with the Cometflash is spread out in 4
pulses over 200ms, each pulse is 5.25J in 2ms.
At 500 volts, 5.25J, 2ms, that equates to 5.25A peak.
Over the duration of the 21J Cometflash, 500V, 200ms, that works out to
be an average current of .21A.
Over an entire minute which is 45 pulses according to Whelen, 945J,
500V, 60s, figures out at 0.03A average.
At 5.25A, the I
2R losses are 11W based on 22 gauge, 16 ohm/1000, 25'
run. Over the duration of the 21J Cometflash, 0.08W. Over the entire
minute, 0.0004W.
None of this seems to concern me so I don't see the need for anything
over 22 gauge. I know there must be something, so WHAT AM I MISSING?
---
Shannon Knoepflein <---> kycshann@kyol.net
Message 6
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--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
I am designing a switch module called the "AutoE-bus'Witch" that does the following:
It contains the E-bus switch, the bus isolating diode, and a low voltage warning
light. Exactly how this device will function is still in doubt, and suggestions
would be appreciated.
Here's what I think so far: (ON-ON-ON toggle switch): General notes--Isolator Diode
always active, LED on switch is red/green and red LED on panel have bright/dim
jumper. Device is for 14.5 VDC (key parts are not available in higher voltage
for now but will be later). Led color always indicates status of main bus
volts.
Up Position-ON; Aux power selected ON. LED red if Main Bus Volts Low, otherwise
green.
Center Position-- AUTO; LED normally green, automatic switch aux power to E-bus
if needed. LED then red
Down Position-- OFF; E-bus switch open (OFF), LED normally OFF but LED red if Main
Bus Volts Low.
Questions: What max sustained current is expected through the E-bus switch? Is
the control logic here okay? What other features might be desirable in this "Single-Switch
Solution".
Thanks for all your help.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
When trouble arises and things look bad, there is always one individual
who perceives a solution and is willing to take command.
Very often, that individual is crazy.
--Dave Barry
Message 7
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| Subject: | Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 07:06 AM 4/8/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
>
>Is it possible for Sam to use one wire for each strobe using the center
>conductor for positive current and the shield for the negative (Instead
>of two wires - one for positive and one for ground)?? Could the same
>thing be done for the position light?
Sharing ground between the two systems would couple strobe
tube noises right into the 14v distribution system any
time the nav lights are on. Shields can be used for
effective ground returns and a single shielded wire might
go into a tight tube easier than two separate strands.
Sam, you might see if you can get a shielded trio and a
shielded single to share the tube you have. If push
comes to shove, you might consider dropping your strobe
wires down to a 22AWG trio . . . that was discussed
earlier on the list.
Bob . . .
Message 8
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--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
In my little non-crowbar OVM (doesn't blow a fuse or trip a breaker...just disconnects
the line), There is a glitch filter to take care of nuisance trips. I
haven't yet sold one of these because I can't get any test feedback. (Sitting
in the shell of my Glastar going Vroom Vroom doesn't do it.) Anyone interested
in testing it?
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
"Nothing is too wonderful to be true."
- James Clerk Maxwell, discoverer of electromagnetism
"Too much of a good thing can be wonderful."
- Mae West, discoverer of personal magnetism
Message 9
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| Subject: | Re: Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/8/2003 8:47:03 AM Central Standard Time,
kycshann@kyol.net writes:
> Since we are on the strobe kick again, I never have convinced myself
> that 18 gauge is necessary with the Whelen strobes. 22 certainly would
> be easier for Sam to run in his small tube. It seems Old Bob has run 22
> with success.
>
Good Morning Shannon,
Just for what it's worth, my tip tanks came from the manufacturer with a one
quarter inch OD aluminum tube glassed in place to serve as a conduit to the
running lights.
I don't recall the dimensions just now, but I think that tubing has an ID
around .185 inch.
I measured #22 Tefzel wire and found that it measured something under .060.
That allowed seven wires to fit through the tubing comfortably. I had
planned on using wire lube (as suggested by Cy) and pulling it through with a
one wire snake.
However, I bundled the seven wires together, taped the end tightly and, using
another old house wiring technique, just shoved the bundle through the
conduit.
It worked even better than I had anticipated.
I have had no noise in the audio system and the strobes seem to flash quite
brightly. As I mentioned before, I did check with Whelen before I decided on
that course of action. They thought it should be OK. It was, and still IS!
Happy Skies,
Old Bob
Message 10
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| Subject: | Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Shannon Knoepflein" <kycshann@kyol.net>
Thanks Bob, appreciate the reply. One more question if you don't mind.
Which power supply do you have and do you know the amount of energy it
puts out per flash? Thanks for the help.
---
Shannon Knoepflein <---> kycshann@kyol.net
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
BobsV35B@aol.com
Subject: Re: AeroElectric-List: Must strobe feed wires be shielded?
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/8/2003 8:47:03 AM Central Standard Time,
kycshann@kyol.net writes:
> Since we are on the strobe kick again, I never have convinced myself
> that 18 gauge is necessary with the Whelen strobes. 22 certainly
would
> be easier for Sam to run in his small tube. It seems Old Bob has run
22
> with success.
>
Good Morning Shannon,
Just for what it's worth, my tip tanks came from the manufacturer with a
one
quarter inch OD aluminum tube glassed in place to serve as a conduit to
the
running lights.
I don't recall the dimensions just now, but I think that tubing has an
around .185 inch.
I measured #22 Tefzel wire and found that it measured something under
.060.
That allowed seven wires to fit through the tubing comfortably. I had
planned on using wire lube (as suggested by Cy) and pulling it through
with a
one wire snake.
However, I bundled the seven wires together, taped the end tightly and,
using
another old house wiring technique, just shoved the bundle through the
conduit.
It worked even better than I had anticipated.
I have had no noise in the audio system and the strobes seem to flash
quite
brightly. As I mentioned before, I did check with Whelen before I
decided on
that course of action. They thought it should be OK. It was, and still
IS!
Happy Skies,
Old Bob
Message 11
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| Subject: | DRE-244e Intercom wiring |
--> AeroElectric-List message posted by: "James E. Clark" <james@nextupventures.com>
When I go to the airport I will see if I can get a copy of it for you as
well.
Great intercom. Great people too.
James
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert
> L. Nuckolls, III
> Sent: Monday, April 07, 2003 7:00 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: DRE-244e Intercom wiring
>
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls,
> III" <bob.nuckolls@cox.net>
>
> At 03:12 PM 4/7/2003 -0500, you wrote:
> >--> AeroElectric-List message posted by: "Phil Birkelbach"
> ><phil@petrasoft.net>
> >
> >I bought a DRE-244e Intercom off of Ebay and it came without any wiring
> >diagrams. If anybody has one of these units could I get wiring
> diagram or a
> >pinout description? Thanks.
>
> That one's not in my list of installation drawings.
> Try contacting the manufacturer. The webpage for
> your intercom is at:
> http://www.drecomm.com/244eproduct.htm
> Their customer service department can be
> e-mailed at:
>
> mailto:cs@drecomm.com
>
>
> Bob . . .
>
> --------------------------------------------
> ( Knowing about a thing is different than )
> ( understanding it. One can know a lot )
> ( and still understand nothing. )
> ( C.F. Kettering )
> --------------------------------------------
>
>
Message 12
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| Subject: | Instrument Panel Lights |
RV7 Matronics List <rv7-list@matronics.com>
--> AeroElectric-List message posted by: Julia <wings97302@yahoo.com>
I bought a bunch of different panel lights and LED's from various companies - I
need one for low oil pressure, one for low fuel pressure, and one for low voltage
warning lights.
Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can
get it in different colors and it's $12.00 - save yourself the trouble and
get one of these first - just get one and you'll see what i mean. Many of the
LED's were not bright enough and some you could not see very well if it was
mounted on the right side of the panel and you were on the left side.
my 2 cents for the day.
Sun'N Fun was a blast - the RV is the right thing to be building. In the lower
price range the Zenith 601 was a hot ticket.
---------------------------------
Message 13
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| Subject: | Fluxuating Amp meter |
04/08/2003 01:29:54 PM
--> AeroElectric-List message posted by: "Terry Lamp" <tlamp@genesishcs.org>
I just started flying my new Long EZ and noticed that the VM 1000 amp meter
fluxuates from 11 to 8 to 6 to 4 tahn recycles. This is about a 30 sec
cycle. While flying, about 2400 RPM.
Inductive pickup is around the cable from the Nipindenso alternator to the
battery.
Wired pretty much as per Z-9 and run the LAR3 from B&C.
Is this a normal reading?
Running strobes, one elec. ign., Garmin 150XL and and intercomm.
Thanks,
Terry
Long EZ
Ohio
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not the intended recipient, any disclosure, dissemination,
distribution, copying or other use of the communication or its
substance is prohibited. If you have received this e-mail in error,
please reply to this e-mail indicating you are not the intended
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Message 14
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| Subject: | Fluxuating Amp meter |
--> AeroElectric-List message posted by: "Rhett Westerman" <Rhettwesterman@cox.net>
I would say that fluctuation is extreme. Mine fluxuates too but between 0
and 6. I have adjusted the zero output per vision but have not replaced the
unit as vision says that it is likely not bad. It is just annoying as I have
to keep some current draw on to stop the low amp beeps. I've tried e/t with
grounding etc and no joy.
best,
Rhett
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Terry
Lamp
Subject: AeroElectric-List: Fluxuating Amp meter
--> AeroElectric-List message posted by: "Terry Lamp" <tlamp@genesishcs.org>
I just started flying my new Long EZ and noticed that the VM 1000 amp meter
fluxuates from 11 to 8 to 6 to 4 tahn recycles. This is about a 30 sec
cycle. While flying, about 2400 RPM.
Inductive pickup is around the cable from the Nipindenso alternator to the
battery.
Wired pretty much as per Z-9 and run the LAR3 from B&C.
Is this a normal reading?
Running strobes, one elec. ign., Garmin 150XL and and intercomm.
Thanks,
Terry
Long EZ
Ohio
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Message 15
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| Subject: | Re: Instrument Panel Lights |
--> AeroElectric-List message posted by: Julia <wings97302@yahoo.com>
http://www.bandc.biz/
above is the link to the site with the light for sale
Julia <wings97302@yahoo.com> wrote:--> AeroElectric-List message posted by: Julia
I bought a bunch of different panel lights and LED's from various companies - I
need one for low oil pressure, one for low fuel pressure, and one for low voltage
warning lights.
Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can
get it in different colors and it's $12.00 - save yourself the trouble and get
one of these first - just get one and you'll see what i mean. Many of the LED's
were not bright enough and some you could not see very well if it was mounted
on the right side of the panel and you were on the left side.
my 2 cents for the day.
Sun'N Fun was a blast - the RV is the right thing to be building. In the lower
price range the Zenith 601 was a hot ticket.
---------------------------------
---------------------------------
Message 16
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| Subject: | Re: Instrument Panel Lights |
--> AeroElectric-List message posted by: Julia <wings97302@yahoo.com>
And on the site the part # is WLA - not what I previously mentioned - sorry about
that
Julia <wings97302@yahoo.com> wrote:--> AeroElectric-List message posted by: Julia
http://www.bandc.biz/
above is the link to the site with the light for sale
Julia wrote:--> AeroElectric-List message posted by: Julia
I bought a bunch of different panel lights and LED's from various companies - I
need one for low oil pressure, one for low fuel pressure, and one for low voltage
warning lights.
Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can
get it in different colors and it's $12.00 - save yourself the trouble and get
one of these first - just get one and you'll see what i mean. Many of the LED's
were not bright enough and some you could not see very well if it was mounted
on the right side of the panel and you were on the left side.
my 2 cents for the day.
Sun'N Fun was a blast - the RV is the right thing to be building. In the lower
price range the Zenith 601 was a hot ticket.
---------------------------------
---------------------------------
---------------------------------
Message 17
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|
| Subject: | Harware locations versus noise. |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>Comments/Questions: Alternator Voltage Regulators are these considered
>"noisy" items that sould be on the hot side of the firewall away from
>radios or are they benign and canbe located on the cabin side without any
>noise problems?
You can mount them where-ever . . . if there are any noise issues,
they will involve CONDUCTED noise that travels over wiring
as opposed to RADIATED noise that jumps from antagonist to
victim.
Mount them where it makes the most sense for ease of maintenance.
Practice good system architecture as described in appendix
Z drawings and the likelihood of any noise problems is
low and easy to fix if they do show up.
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 18
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: Rino <lacombr@nbnet.nb.ca>
>
> Where am I going wrong? Where did the hundreds
> who have participated in the crafting and maintenance
> of DO-160 over the past two decades go astray?
>
> Bob . .
What about the billions of cars on the road today WITHOUT an avionics
SWITCH ? Do they not have any electronics on board?
Rino
Message 19
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@tenforward.com>
Snipped from Bob's comments in reply to the EI discussion
See My comments following yours below
> Perhaps I can suggest this. Take a scope and go look
> at the output from the cigar lighter on a car. Set up to
> + slope trigger at say, 20 volts and then crank the engine.
> My Tektronix 220 could not capture a single transient at
> ANY horizontal resolution. Tried triggering on - slope
> at zero volts. Same result. I'd say my GMC van is roughly
> equal to C-150 for cranking currents and DC system impedance.
>
> This is typical of what I've captured on a number of
> airplanes ranging from C-150 to Beechjets over the past
> 25 years measured with all manner of scopes, chart
> recorders and high speed (8,000 samples/second)
> data acquisition systems.
>
> Where am I going wrong? Where did the hundreds
> who have participated in the crafting and maintenance
> of DO-160 over the past two decades go astray?
>
> Bob . . .
Bob;
I cannot find any info on your Tek 220 but I assume its similar to the Tek
221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It
takes more like 200,000,000 SPS.
That scope is way too slow to see transients that I have observed during
starting and stopping of a bare bones auto setup with all the normal built
in suppression removed.
Sure it will display a huge very slow transient but not the fast ones or the
ringing multiple transients usually following the major event.
This takes a scope of triggering on a 50Mhz (nominal) or higher frequency
pulse (rise times of a few nanoseconds), having a horizontal single sweep
speed set to at least 10 nanoseconds per division and either very high speed
storage or a camera. Most of the available analog storage scopes are too
slow in the storage mode. A single sweep is too faint for normal single shot
vu and only the higher speed horizontal triggering modules will even
trigger. As the transient is a single shot event there must be some way to
hole it for human display. Thus either a fast storage scope or scope camera.
The best way to see if there is a transient is with a good Transient
Voltmeter but they are expensive and special purpose.
Yet these sharp fast high voltage transients will pass thru a 10-100 mfd
electrolytic cap on the input of an electronic instrument and damage
internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large
number at the frequencies of interest. I have demonstrated this years ago
and thus I install transorbs in all my designs. This is the design choice of
the auto industry and we should learn from their experience.
For the last 20 or more years autos have Transorbs built into most (if not
all) electronic modules, including the IGN system. Not usually a discrete
item but part of one or more IC's. These Transorbs are special super fast
response Zener diodes, in fact normal Zener diodes are not fast enough to
stop the transient from getting past.
Thus if you try to find transients on most any modern automobile you will
not find them even with the proper equipment. The many internal Transorbs
are clipping them on the way to the Lighter so there are none left to
detect.
On the other hand it would appear that even modern aircraft electrical
designs (consider the FADEC low V issues) fail to address the "lessens
learned" in the auto industry regarding starting and shutdown voltages and
transients (which in many cases cannot even be seen with the normally used
test equipment).
While the transients I am addressing are not always present, they sometimes
do damage equipment and unless special test procedures are used they are
simply not seen and thus do not exist in the minds of many design engineers.
In conclusion:
I am saying I do not think your test methods ( I know it, if your Tek scope
is as I believe it is regarding frequency response etc.) are capable of
seeing potentially damaging transients and your test article (an auto) has
already designed in transient suppressors so any transients you are looking
for are already clipped and thus even with proper test setup would not be
found.
The auto industry learned the hard way and as near as I can find, many in
the aircraft industry are not considering the lessens learned in the auto
industry. As aircraft electrical systems move from mags and generators to
alternators and solid state electronics, and avionics become more complex,
the auto and aircraft electrical design needs will continue to converge.
This is not to say the aircraft instruments/avionics should not be designed
to withstand the fast transients and low voltage starting issues, but
knowing how to protect for fast transients (for under a dollar) is a simple
fix for homebuilders and the low voltage issues with FADEC, RMI and EI among
others is up to the individual designer to consider.
Properly selected and connected transorbs and a backup battery are simple
solutions IF your decision is to use an instrument that is not fully
internally protected. The key to me is knowing what is needed.
Paul
Message 20
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
> --> AeroElectric-List message posted by: "Paul Messinger"
> <paulm@tenforward.com>
>
> Snipped from Bob's comments in reply to the EI discussion
>
> See My comments following yours below
>
>> Perhaps I can suggest this. Take a scope and go look
snip
>
> This takes a scope of triggering on a 50Mhz (nominal) or higher
> frequency pulse (rise times of a few nanoseconds), having a horizontal
> single sweep speed set to at least 10 nanoseconds per division and
> either very high speed storage or a camera. Most of the available analog
> storage scopes are too slow in the storage mode. A single sweep is too
> faint for normal single shot vu and only the higher speed horizontal
> triggering modules will even trigger. As the transient is a single shot
> event there must be some way to hole it for human display. Thus either a
> fast storage scope or scope camera.
Do you know what is causing these high frequency/energy transients on
the power bus? I am guess it could be arcing of relay contacts. I also
wonder how far from the transient source is the energy carried before being
rolled-off in the uncontrolled impedance environment that is the powerbus.
Interesting discussion.
Regards,
Matt-
N34RD
Message 21
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Cy Galley" <cgalley@qcbc.org>
So why not install a transorb in the electronic supply line and be done with
the problem. Are they that expensive?
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cgalley@qcbc.org or experimenter@eaa.org
Always looking for articles for the Experimenter
----- Original Message -----
From: "Paul Messinger" <paulm@tenforward.com>
Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering?
> --> AeroElectric-List message posted by: "Paul Messinger"
<paulm@tenforward.com>
>
> Snipped from Bob's comments in reply to the EI discussion
>
> See My comments following yours below
>
> > Perhaps I can suggest this. Take a scope and go look
> > at the output from the cigar lighter on a car. Set up to
> > + slope trigger at say, 20 volts and then crank the engine.
> > My Tektronix 220 could not capture a single transient at
> > ANY horizontal resolution. Tried triggering on - slope
> > at zero volts. Same result. I'd say my GMC van is roughly
> > equal to C-150 for cranking currents and DC system impedance.
> >
> > This is typical of what I've captured on a number of
> > airplanes ranging from C-150 to Beechjets over the past
> > 25 years measured with all manner of scopes, chart
> > recorders and high speed (8,000 samples/second)
> > data acquisition systems.
> >
> > Where am I going wrong? Where did the hundreds
> > who have participated in the crafting and maintenance
> > of DO-160 over the past two decades go astray?
> >
> > Bob . . .
>
> Bob;
>
> I cannot find any info on your Tek 220 but I assume its similar to the Tek
> 221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It
> takes more like 200,000,000 SPS.
>
> That scope is way too slow to see transients that I have observed during
> starting and stopping of a bare bones auto setup with all the normal built
> in suppression removed.
>
> Sure it will display a huge very slow transient but not the fast ones or
the
> ringing multiple transients usually following the major event.
>
> This takes a scope of triggering on a 50Mhz (nominal) or higher frequency
> pulse (rise times of a few nanoseconds), having a horizontal single sweep
> speed set to at least 10 nanoseconds per division and either very high
speed
> storage or a camera. Most of the available analog storage scopes are too
> slow in the storage mode. A single sweep is too faint for normal single
shot
> vu and only the higher speed horizontal triggering modules will even
> trigger. As the transient is a single shot event there must be some way to
> hole it for human display. Thus either a fast storage scope or scope
camera.
>
> The best way to see if there is a transient is with a good Transient
> Voltmeter but they are expensive and special purpose.
>
> Yet these sharp fast high voltage transients will pass thru a 10-100 mfd
> electrolytic cap on the input of an electronic instrument and damage
> internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large
> number at the frequencies of interest. I have demonstrated this years ago
> and thus I install transorbs in all my designs. This is the design choice
of
> the auto industry and we should learn from their experience.
>
> For the last 20 or more years autos have Transorbs built into most (if not
> all) electronic modules, including the IGN system. Not usually a discrete
> item but part of one or more IC's. These Transorbs are special super fast
> response Zener diodes, in fact normal Zener diodes are not fast enough to
> stop the transient from getting past.
>
> Thus if you try to find transients on most any modern automobile you will
> not find them even with the proper equipment. The many internal Transorbs
> are clipping them on the way to the Lighter so there are none left to
> detect.
>
> On the other hand it would appear that even modern aircraft electrical
> designs (consider the FADEC low V issues) fail to address the "lessens
> learned" in the auto industry regarding starting and shutdown voltages and
> transients (which in many cases cannot even be seen with the normally used
> test equipment).
>
> While the transients I am addressing are not always present, they
sometimes
> do damage equipment and unless special test procedures are used they are
> simply not seen and thus do not exist in the minds of many design
engineers.
>
> In conclusion:
> I am saying I do not think your test methods ( I know it, if your Tek
scope
> is as I believe it is regarding frequency response etc.) are capable of
> seeing potentially damaging transients and your test article (an auto) has
> already designed in transient suppressors so any transients you are
looking
> for are already clipped and thus even with proper test setup would not be
> found.
>
> The auto industry learned the hard way and as near as I can find, many in
> the aircraft industry are not considering the lessens learned in the auto
> industry. As aircraft electrical systems move from mags and generators to
> alternators and solid state electronics, and avionics become more complex,
> the auto and aircraft electrical design needs will continue to converge.
>
> This is not to say the aircraft instruments/avionics should not be
designed
> to withstand the fast transients and low voltage starting issues, but
> knowing how to protect for fast transients (for under a dollar) is a
simple
> fix for homebuilders and the low voltage issues with FADEC, RMI and EI
among
> others is up to the individual designer to consider.
>
> Properly selected and connected transorbs and a backup battery are simple
> solutions IF your decision is to use an instrument that is not fully
> internally protected. The key to me is knowing what is needed.
>
> Paul
>
>
Message 22
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 04:57 PM 4/8/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: "Paul Messinger"
><paulm@tenforward.com>
>
>Snipped from Bob's comments in reply to the EI discussion
>
>See My comments following yours below
>
> > Perhaps I can suggest this. Take a scope and go look
> > at the output from the cigar lighter on a car. Set up to
> > + slope trigger at say, 20 volts and then crank the engine.
> > My Tektronix 220 could not capture a single transient at
> > ANY horizontal resolution. Tried triggering on - slope
> > at zero volts. Same result. I'd say my GMC van is roughly
> > equal to C-150 for cranking currents and DC system impedance.
> >
> > This is typical of what I've captured on a number of
> > airplanes ranging from C-150 to Beechjets over the past
> > 25 years measured with all manner of scopes, chart
> > recorders and high speed (8,000 samples/second)
> > data acquisition systems.
> >
> > Where am I going wrong? Where did the hundreds
> > who have participated in the crafting and maintenance
> > of DO-160 over the past two decades go astray?
> >
> > Bob . . .
>
>Bob;
>
>I cannot find any info on your Tek 220 but I assume its similar to the Tek
>221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It
>takes more like 200,000,000 SPS.
It's a 1 GigaSamples/second digital storage scope.
See http://www.metricsales.com/c_tektronix/40W_10992_4.pdf
It's specified as capable of capturing a 10 nS pulse.
>That scope is way too slow to see transients that I have observed during
>starting and stopping of a bare bones auto setup with all the normal built
>in suppression removed.
>Sure it will display a huge very slow transient but not the fast ones or the
>ringing multiple transients usually following the major event.
>
>This takes a scope of triggering on a 50Mhz (nominal) or higher frequency
>pulse (rise times of a few nanoseconds), having a horizontal single sweep
>speed set to at least 10 nanoseconds per division and either very high speed
>storage or a camera. Most of the available analog storage scopes are too
>slow in the storage mode. A single sweep is too faint for normal single shot
>vu and only the higher speed horizontal triggering modules will even
>trigger. As the transient is a single shot event there must be some way to
>hole it for human display. Thus either a fast storage scope or scope camera.
>
>The best way to see if there is a transient is with a good Transient
>Voltmeter but they are expensive and special purpose.
I've built them with fast peak-hold circuits . . . not difficult.
>Yet these sharp fast high voltage transients will pass thru a 10-100 mfd
>electrolytic cap on the input of an electronic instrument and damage
>internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large
>number at the frequencies of interest. I have demonstrated this years ago
>and thus I install transorbs in all my designs. This is the design choice of
>the auto industry and we should learn from their experience.
Sure . . . Transorbs are fine devices, we use them by the fist-full
in lots of products. We also apply the usual high quality capacitors
and series devices to raise the apparent source impedance of the
stress . . . this is all jelly-bean technology. The stuff we bolt
to airplanes is now routinely tested for the effects of lighting
strike to the airframe and while it raises complexity of i/o in
terms of parts count, none of the parts are expensive or exotic.
>For the last 20 or more years autos have Transorbs built into most (if not
>all) electronic modules, including the IGN system. Not usually a discrete
>item but part of one or more IC's. These Transorbs are special super fast
>response Zener diodes, in fact normal Zener diodes are not fast enough to
>stop the transient from getting past.
>
>Thus if you try to find transients on most any modern automobile you will
>not find them even with the proper equipment. The many internal Transorbs
>are clipping them on the way to the Lighter so there are none left to
>detect.
>
>On the other hand it would appear that even modern aircraft electrical
>designs (consider the FADEC low V issues) . . .
Yup, another big name company found that the boot
in their rear was their own . . . happens all the time.
> . . . fail to address the "lessens
>learned" in the auto industry regarding starting and shutdown voltages and
>transients (which in many cases cannot even be seen with the normally used
>test equipment).
Your stretching it a tad here my friend . . . define "normally used" . . .
The folks who crafted DO-160 comprise the talents of hundreds of
engineers from virtually every company in the US with an interest
in aviation including manufacturers, consumer groups and government.
If you think you and I are the only ones to ever have discussed
transients, either real or imagined, you are mistaken. The equipment
and test methods used to define DO-160 recommendations for testing
are the best available. Experiments are repeated and/or reviewed
by multiple investigators and confirmed before being pronounced valid.
I can quote from my own experience but much of my success has
to give credit for many lessons learned as exemplified by
the contents of DO-160 and the experience-base that was tapped
to create the document. And "we're" still learning. DO-160
chapters are constantly being re-evaluated and revised as
new threats arise or better techniques for meeting them are
devised.
>While the transients I am addressing are not always present, they sometimes
>do damage equipment and unless special test procedures are used they are
>simply not seen and thus do not exist in the minds of many design engineers.
If you believe my head is in the sand somewhere, please cite
an experiment I can go duplicate that supports your assertion.
Let's turn the engineering community on to a hazard heretofore
unknown to the standing committee on DO-160. We can co-author
a paper and become famous.
>In conclusion:
> I am saying I do not think your test methods ( I know it, if your Tek scope
>is as I believe it is regarding frequency response etc.) are capable of
>seeing potentially damaging transients and your test article (an auto) has
>already designed in transient suppressors so any transients you are looking
>for are already clipped and thus even with proper test setup would not be
>found.
Fair enough. The first time I did the automotive experiment
was on my '72 or '73 Vega . . . don't think it had any transorb
protected systems in it. That was when I was working at Electro-Mech
and the 'scope would have been a Tek 465.
My wife's uncle has an older Chevy pickup he's really proud of.
I'll see if he'll let me hook my 'scope to it. But the fellow
from E.I. was alluding to the existence of killer spikes far
outside the range of stresses his own products could survive
in spite of the fact his products could take on DO-160 without
breaking a sweat. Although not stated directly, the implication
is that DO-160 has badly missed the mark with respect to spikes
that spark in the dark.
>The auto industry learned the hard way and as near as I can find, many in
>the aircraft industry are not considering the lessens learned in the auto
>industry. As aircraft electrical systems move from mags and generators to
>alternators and solid state electronics, and avionics become more complex,
>the auto and aircraft electrical design needs will continue to converge.
>
>This is not to say the aircraft instruments/avionics should not be designed
>to withstand the fast transients and low voltage starting issues, but
>knowing how to protect for fast transients (for under a dollar) is a simple
>fix for homebuilders and the low voltage issues with FADEC, RMI and EI among
>others is up to the individual designer to consider.
I think they HAVE taken capitalized on many lessons learned - else DO-160
would not have come into existence. Now, whether or not folks who
supply product to the industry know how to take advantage of these
lessons is another matter. I'm aware of discussions with folks from
a REALLY BIG name company who have stepped into a $millions$ pothole
for not taking time to study and use lessons learned. It's now
getting down to debating the definition of "is" . . .
>Properly selected and connected transorbs and a backup battery are simple
>solutions IF your decision is to use an instrument that is not fully
>internally protected. The key to me is knowing what is needed.
Don't disagree with much of what you've written. But none
of this addresses the issue with respect to E.I. To date, the
writer had given no data and only regurgitated 40 year old
mantras. I've asked no more of him than I would of any fellow
engineer. Cite the reviewed and repeatable experiments either
of his own work or that of others to support his position that
explains why his customers need to pamper his products. Could
he be overlooking the $1 solution?
Spikes of the nature you've cited have no energy in them.
Self inductance of just power lead wires significantly
raises source impedance of any such spike as to render
it nearly toothless. When I've watched the bus with slower
equipment, my interest was in transients that carried
some real energy. Those tens-of-nanosecond wide events
are like cap pistols at a good July 4th celebration.
They're easy to filter and/or clamp off with ordinary
techniques. Whether they exist or not I can deduce
no reason for a credible designer to hide behind an
avionics master switch protected bus.
I've designed dozens of black boxes, some that include
microprocessors that run have run the DO-160 test
gauntlet including lightning stroke. They all run happily tied
right to the main bus of the airframe . . . I wouldn't THINK
of offering a product that couldn't handle ANYTHING a normally
operating airplane throws at it. As you and I have both noted,
it's EASY.
All I expect from E.I. is to be good engineers and
back up their expectations and claims with good data
from repeatable experiments, spread the word on good
information, debunk bad information and make Carl
Sagan proud of us all.
Bob . . .
Message 23
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:38 PM 4/8/2003 -0300, you wrote:
>--> AeroElectric-List message posted by: Rino <lacombr@nbnet.nb.ca>
>
> >
> > Where am I going wrong? Where did the hundreds
> > who have participated in the crafting and maintenance
> > of DO-160 over the past two decades go astray?
> >
> > Bob . .
>
>
>What about the billions of cars on the road today WITHOUT an avionics
>SWITCH ? Do they not have any electronics on board?
sho'nuf do . . . and they all benefit from a plethora
of components and techniques designed to deal comfortably
with anything the car (or any other vehicle) can throw
at it. It's all tinker-toy technology. See my other post.
Bob . . .
Message 24
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| Subject: | Approach-Systems Avionics Wiring System |
--> AeroElectric-List message posted by: "DeWitt (Dee) Whittington" <dewittw@earthlink.net>
Just got back from Sun 'n Fun. There I attended a forum presented by
Approach Systems who claim to have a product that will let you "Wire an
avionics stack in LESS THAN 3 hours with Fast Stack.".
The packed tent heard about a system that's been on the market since
Oshkosh 2002. This company makes a "hub" consisting of 8 layers of PC
boards and custom built connecting cables to provide all the interconnect
wiring for your avionics stack. You tell them what particular avionics
items you have in your panel and how long the cables must be. However,
they leave it up to you to connect buss power, ground, lighting and
antennas as well as mount the avionics boxes in the panel.
They suggest that it will save hours of build time and debugging,
especially for the segment of the homebuilding public who dread
wiring their avionics stack. Approach Systems also claims that their
system makes it easy to change or add boxes in the future to your
stack. Some of their systems have been put in certified aircraft with 337s.
On initial hearing, seemed like these folks may have something. If you
haven't heard about them, check out their web site, www.approach-systems.com
Any comments from someone who has bought one of their systems or have heard
their presentation?
DeWitt Whittington A&P
406 N Mulberry St
Richmond, VA 23220
(804) 358-4333 phone and fax
dewittw@earthlink.net
Message 25
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| Subject: | Re: Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/8/03 9:49:11 AM Central Daylight Time, kycshann@kyol.net
writes:
> Which power supply do you have and do you know the amount of energy it
> puts out per flash? Thanks for the help.
>
Good Evening Shannon,
I have the Whelen A490A power supplies. One on the tail and one in each wing
tip. They are connected with a trigger wire so that they flash together.
The ad in the Aircraft Spruce catalog says that it produces an accumulated 34
joules of energy. Any idea what that means?
Happy Skies,
Old Bob
Message 26
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@tenforward.com>
Well under $1.00 for the larger powered ones.
As far as I am concerned that would be the solution however I would put one
on the unit side of the (fuse or CB) as failure of the device could produce
a hard short to ground (along with perhaps dozens of other components.
However they are very hard to damage.
I have yet to find an auto designed device with out such protection. Not
sure about items designed to be on the auto acc buss as that buss is off
during engine start and or is 3 rd party designed for the acc buss.
In any event the main components of the auto electic system have supression
and that supression stops things before getting to the ass buss.
At least that is what I have found in limited investigation of auto systems
etc.
Paul
----- Original Message -----
From: "Cy Galley" <cgalley@qcbc.org>
Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering?
> --> AeroElectric-List message posted by: "Cy Galley" <cgalley@qcbc.org>
>
> So why not install a transorb in the electronic supply line and be done
with
> the problem. Are they that expensive?
>
> Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
>
> Editor, EAA Safety Programs
> cgalley@qcbc.org or experimenter@eaa.org
Message 27
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@tenforward.com>
----- Original Message -----
From: "Rino" <lacombr@nbnet.nb.ca>
>
> What about the billions of cars on the road today WITHOUT an avionics
> SWITCH ? Do they not have any electronics on board?
>
> Rino
In a way as the ign switch turns off the radios etc during the starting
process.
Paul
Message 28
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@tenforward.com>
Sorry about your scope but I stand by my commenst that there is nothing to
see as modern autos are already supressed. As for aircraft I do not know
about the latest designs and production models. However to think that we
experimental builders will always spend the big bucks for the latest state
of the art in avionics is as you say head in the sand. Most of us cannot
afford the latest for a $20-50K panel and need to put up with either older
designs still in production and whle new not new designs.
The fix is so simple. $5 worth of transorbs and the worry is gone.
The transients I have seen will travel all over your system and while I
agree the energi is tiny its huge to a CMOS gate in an IC.
As for the experts hopefully the ones who designed the FADEC that will not
work at 8V were not part of your team that came up with your new specs.
I do not waht to start another time consuming discussion as again we see the
same issue in a different light.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering?
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 04:57 PM 4/8/2003 -0700, you wrote:
> >--> AeroElectric-List message posted by: "Paul Messinger"
> ><paulm@tenforward.com>
> >
> >Snipped from Bob's comments in reply to the EI discussion
> >
> >See My comments following yours below
> >
> > > Perhaps I can suggest this. Take a scope and go look
> > > at the output from the cigar lighter on a car. Set up to
> > > + slope trigger at say, 20 volts and then crank the engine.
> > > My Tektronix 220 could not capture a single transient at
> > > ANY horizontal resolution. Tried triggering on - slope
> > > at zero volts. Same result. I'd say my GMC van is roughly
> > > equal to C-150 for cranking currents and DC system impedance.
> > >
> > > This is typical of what I've captured on a number of
> > > airplanes ranging from C-150 to Beechjets over the past
> > > 25 years measured with all manner of scopes, chart
> > > recorders and high speed (8,000 samples/second)
> > > data acquisition systems.
> > >
> > > Where am I going wrong? Where did the hundreds
> > > who have participated in the crafting and maintenance
> > > of DO-160 over the past two decades go astray?
> > >
> > > Bob . . .
> >
> >Bob;
> >
> >I cannot find any info on your Tek 220 but I assume its similar to the
Tek
> >221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It
> >takes more like 200,000,000 SPS.
>
> It's a 1 GigaSamples/second digital storage scope.
> See http://www.metricsales.com/c_tektronix/40W_10992_4.pdf
> It's specified as capable of capturing a 10 nS pulse.
>
> >That scope is way too slow to see transients that I have observed during
> >starting and stopping of a bare bones auto setup with all the normal
built
> >in suppression removed.
>
>
> >Sure it will display a huge very slow transient but not the fast ones or
the
> >ringing multiple transients usually following the major event.
> >
> >This takes a scope of triggering on a 50Mhz (nominal) or higher frequency
> >pulse (rise times of a few nanoseconds), having a horizontal single sweep
> >speed set to at least 10 nanoseconds per division and either very high
speed
> >storage or a camera. Most of the available analog storage scopes are too
> >slow in the storage mode. A single sweep is too faint for normal single
shot
> >vu and only the higher speed horizontal triggering modules will even
> >trigger. As the transient is a single shot event there must be some way
to
> >hole it for human display. Thus either a fast storage scope or scope
camera.
> >
> >The best way to see if there is a transient is with a good Transient
> >Voltmeter but they are expensive and special purpose.
>
> I've built them with fast peak-hold circuits . . . not difficult.
>
>
> >Yet these sharp fast high voltage transients will pass thru a 10-100 mfd
> >electrolytic cap on the input of an electronic instrument and damage
> >internal CMOS etc IC's. The cap's reactance (in ohms) increases to a
large
> >number at the frequencies of interest. I have demonstrated this years ago
> >and thus I install transorbs in all my designs. This is the design choice
of
> >the auto industry and we should learn from their experience.
>
> Sure . . . Transorbs are fine devices, we use them by the fist-full
> in lots of products. We also apply the usual high quality capacitors
> and series devices to raise the apparent source impedance of the
> stress . . . this is all jelly-bean technology. The stuff we bolt
> to airplanes is now routinely tested for the effects of lighting
> strike to the airframe and while it raises complexity of i/o in
> terms of parts count, none of the parts are expensive or exotic.
>
>
> >For the last 20 or more years autos have Transorbs built into most (if
not
> >all) electronic modules, including the IGN system. Not usually a discrete
> >item but part of one or more IC's. These Transorbs are special super fast
> >response Zener diodes, in fact normal Zener diodes are not fast enough to
> >stop the transient from getting past.
> >
> >Thus if you try to find transients on most any modern automobile you will
> >not find them even with the proper equipment. The many internal Transorbs
> >are clipping them on the way to the Lighter so there are none left to
> >detect.
> >
> >On the other hand it would appear that even modern aircraft electrical
> >designs (consider the FADEC low V issues) . . .
>
> Yup, another big name company found that the boot
> in their rear was their own . . . happens all the time.
>
>
> > . . . fail to address the "lessens
> >learned" in the auto industry regarding starting and shutdown voltages
and
> >transients (which in many cases cannot even be seen with the normally
used
> >test equipment).
>
> Your stretching it a tad here my friend . . . define "normally used" .
. .
> The folks who crafted DO-160 comprise the talents of hundreds of
> engineers from virtually every company in the US with an interest
> in aviation including manufacturers, consumer groups and government.
>
> If you think you and I are the only ones to ever have discussed
> transients, either real or imagined, you are mistaken. The equipment
> and test methods used to define DO-160 recommendations for testing
> are the best available. Experiments are repeated and/or reviewed
> by multiple investigators and confirmed before being pronounced valid.
>
> I can quote from my own experience but much of my success has
> to give credit for many lessons learned as exemplified by
> the contents of DO-160 and the experience-base that was tapped
> to create the document. And "we're" still learning. DO-160
> chapters are constantly being re-evaluated and revised as
> new threats arise or better techniques for meeting them are
> devised.
>
>
> >While the transients I am addressing are not always present, they
sometimes
> >do damage equipment and unless special test procedures are used they are
> >simply not seen and thus do not exist in the minds of many design
engineers.
>
> If you believe my head is in the sand somewhere, please cite
> an experiment I can go duplicate that supports your assertion.
> Let's turn the engineering community on to a hazard heretofore
> unknown to the standing committee on DO-160. We can co-author
> a paper and become famous.
>
>
> >In conclusion:
> > I am saying I do not think your test methods ( I know it, if your Tek
scope
> >is as I believe it is regarding frequency response etc.) are capable of
> >seeing potentially damaging transients and your test article (an auto)
has
> >already designed in transient suppressors so any transients you are
looking
> >for are already clipped and thus even with proper test setup would not be
> >found.
>
> Fair enough. The first time I did the automotive experiment
> was on my '72 or '73 Vega . . . don't think it had any transorb
> protected systems in it. That was when I was working at Electro-Mech
> and the 'scope would have been a Tek 465.
>
> My wife's uncle has an older Chevy pickup he's really proud of.
> I'll see if he'll let me hook my 'scope to it. But the fellow
> from E.I. was alluding to the existence of killer spikes far
> outside the range of stresses his own products could survive
> in spite of the fact his products could take on DO-160 without
> breaking a sweat. Although not stated directly, the implication
> is that DO-160 has badly missed the mark with respect to spikes
> that spark in the dark.
>
>
> >The auto industry learned the hard way and as near as I can find, many in
> >the aircraft industry are not considering the lessens learned in the auto
> >industry. As aircraft electrical systems move from mags and generators to
> >alternators and solid state electronics, and avionics become more
complex,
> >the auto and aircraft electrical design needs will continue to converge.
> >
> >This is not to say the aircraft instruments/avionics should not be
designed
> >to withstand the fast transients and low voltage starting issues, but
> >knowing how to protect for fast transients (for under a dollar) is a
simple
> >fix for homebuilders and the low voltage issues with FADEC, RMI and EI
among
> >others is up to the individual designer to consider.
>
> I think they HAVE taken capitalized on many lessons learned - else
DO-160
> would not have come into existence. Now, whether or not folks who
> supply product to the industry know how to take advantage of these
> lessons is another matter. I'm aware of discussions with folks from
> a REALLY BIG name company who have stepped into a $millions$ pothole
> for not taking time to study and use lessons learned. It's now
> getting down to debating the definition of "is" . . .
>
> >Properly selected and connected transorbs and a backup battery are simple
> >solutions IF your decision is to use an instrument that is not fully
> >internally protected. The key to me is knowing what is needed.
>
> Don't disagree with much of what you've written. But none
> of this addresses the issue with respect to E.I. To date, the
> writer had given no data and only regurgitated 40 year old
> mantras. I've asked no more of him than I would of any fellow
> engineer. Cite the reviewed and repeatable experiments either
> of his own work or that of others to support his position that
> explains why his customers need to pamper his products. Could
> he be overlooking the $1 solution?
>
> Spikes of the nature you've cited have no energy in them.
> Self inductance of just power lead wires significantly
> raises source impedance of any such spike as to render
> it nearly toothless. When I've watched the bus with slower
> equipment, my interest was in transients that carried
> some real energy. Those tens-of-nanosecond wide events
> are like cap pistols at a good July 4th celebration.
>
> They're easy to filter and/or clamp off with ordinary
> techniques. Whether they exist or not I can deduce
> no reason for a credible designer to hide behind an
> avionics master switch protected bus.
>
> I've designed dozens of black boxes, some that include
> microprocessors that run have run the DO-160 test
> gauntlet including lightning stroke. They all run happily tied
> right to the main bus of the airframe . . . I wouldn't THINK
> of offering a product that couldn't handle ANYTHING a normally
> operating airplane throws at it. As you and I have both noted,
> it's EASY.
>
> All I expect from E.I. is to be good engineers and
> back up their expectations and claims with good data
> from repeatable experiments, spread the word on good
> information, debunk bad information and make Carl
> Sagan proud of us all.
>
> Bob . . .
>
>
Message 29
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| Subject: | THANK YOU BOB! YOU ARE PROVIDING A GREAT SERVICE |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@tenforward.com>
I do not want anyone to think I am picking on Bob.
He is the only one who has taken the time and interest to help the
experimental aviation community build safe electrical systems. Copying SPAM
Can's is not the way to go. I know of NO WHERE else where one can get good
reliable info in any form much less clearly written for the masses.
I have many feet of manuals, info, etc. on my shelf and find that IF I could
only have one it would be Bob's bible. Yes, its on my shelf and has been for
years!
For anyone not a true expert (real not self proclaimed) its best to follow
ALL of the info in the book. Selective use is not a good idea. Bob has
developed a total safe solution to an electrical system. Its a total system
and should be used as such unless Bob approves otherwise.
While I disagree with Bob from time to time its perhaps only 1% of the
total.
Paul
EAA 55789, TC, FA
Message 30
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| Subject: | Re: Must strobe feed wires be shielded? |
--> AeroElectric-List message posted by: "Richard E. Tasker" <retasker@optonline.net>
>
>
>The ad in the Aircraft Spruce catalog says that it produces an accumulated 34
>joules of energy. Any idea what that means?
>
Not exactly sure what you are expecting for an answer. I'm an
electrical engineer so forgive me if I tell you more than you want to
know. A joule is a measurement of energy. Your 34 joules is 34
watt-seconds or 34 watts for one second. The power supply stores this
amount of energy in an internal storage capacitor. When the strobe is
triggered, the flash is approximately 2 milliseconds (2/1000 seconds)
long, so the 34 watt-seconds is used up in the flash tube in this 2mS
with the flash tube turning this electrical energy into light energy.
To dissipate this 34 joules of energy the strobe tube is using the
equivalent of 17,000 watts for the 2 mS duration of the flash. So your
34 joules is 34 watts for one-second or 17,000 watts for 0.002 seconds.
During the time between flashes, the power supply is recharging the
capacitor to get ready for the next flash.
Dick Tasker
Message 31
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| Subject: | Re: RE: E.I. instruments need pampering? |
--> AeroElectric-List message posted by: Robert McCallum <robert.mccallum2@sympatico.ca>
Paul Messinger wrote:
> >
> > What about the billions of cars on the road today WITHOUT an avionics
> > SWITCH ? Do they not have any electronics on board?
> >
> > Rino
>
> In a way as the ign switch turns off the radios etc. during the starting
> process.
>
> Paul
The vast majority of electronics in modern cars have nothing to do with radios
or anything else on
the accessory buss. The electronics for the most part reside in the plethora of
computers which
control everything from engine management, to door locks, to air bags, NONE of
which are off during
engine start. (And ALL of which presumably continue working quitehappily)
--
Bob McC
DO NOT ARCHIVE
Message 32
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--> AeroElectric-List message posted by: richard@riley.net
I have a brand new, never unpacked, fully factory warranteed UPSAT MX20
that I'm selling for under dealer cost. Retail $7300, my price, $5100. I
can also do a deep discount on a new GX 60 to drive it.
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