AeroElectric-Archive.digest.vol-ed
March 15, 2005 - March 22, 2005
>adapt an electrical layout for the EGG package. That is essentially what
>Z-19 is. The only major mod that I can think of is putting the batteries
>aft of the baggage (RV7A H6). I have already talked to him about this but
>not finalized the details yet. I'll copy this email to Bob for comment.
>
>Bevan
>
>-----Original Message-----
>From: Gary Newsted [SMTP:fcs(at)jlc.net]
>To: subaruaircraft(at)yahoogroups.com
>Subject: [subaruaircraft] Re: CV Report on Ind Mod Failure
>
>
>I should point out that it is CV's optional enunciator module that I
>have trouble with. The EXP is fine for what it does.
>
>When I started working on the electrical design, I was given the EXP
>as a starting point. That is, take this design and make it work for
>us, improve it where you can, but most importantly, make it
>consistent. I feel that this has been achieved, and credit goes to
>many people in this newsgroup for contributing their expertise.
>
>The install guide presents an airworthy adaptation of the EXP for
>Eggenfellner engines, and tries to make the installation clear and
>simple. If you follow the guide, you will have a modern, airworthy
>system which is easy to operate and easy for us to diagnose should it
>ever give you trouble. I occasionally pick on people who deviate
>from this design, not because the design is perfect, but because I
>believe consistency is at the very root of the success of
>Eggenfellner packages.
>
>Let's face it, the thing that will bring down a Subaru will be fuel
>or electrical, so these two systems must be consistent, with lots of
>eyes reviewing these designs. One failure impacts all of us.
>
>Several times we have tossed around the pros and cons
>of "conventional" electrical designs, of which Aeroelectrics are a
>good example. I have not pursued this, although others have. In my
>eyes, conventional designs leave too many doors open which could
>result in inconsistency and even dangerous installations. If some
>qualified individual wanted to invest the time and energy into
>perfecting and thoroughly documenting a conventional design
>specifically for the Eggenfellner engines, I think Jan would support
>the effort (in spirit anyway).
>
>If you are a long ways away from wiring, don't rush into your
>decision either. There just might be better things coming soon.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> system |
| Subject: | Re: Bob's approval electrical for Eggenfelner all electric |
system
system
>
>Yes I agree and I think many other will also be looking for "Bob and Jan
>approved" electrical system for Egg Subies. I suspect that it will be very
>close to Z-19 BUT I for one would sure like to hear from Bob and Jan on
>this.
It's not really up to me. The "blessing" has to come from someone
who intends to use this architecture (or variant) on their
airplane or as a recommended architecture for their product.
My talents go toward suggestions for reduced parts count,
favorable failure mode effects analysis and pilot-friendly
operation. The final buy-off needs to come from the users
based on their understanding and acceptance of simple-
ideas used to assemble the final configuration.
Bob . . .
________________________________________________________________________________
| From: | "Hans Teijgeler" <hans(at)jodel.com> |
| Subject: | Re: Subaru z-figure |
Bob,
I've downloaded a whole bunch from your web site, but the Z figures in those
downloads do not include a Z-19. Could you please give me a steer?
Thanks
Hans
> -----Oorspronkelijk bericht-----
> Van: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> aeroelectric-list-server(at)matronics.com] Namens Robert L. Nuckolls, III
> Verzonden: dinsdag 15 maart 2005 16:05
> Aan: aeroelectric-list(at)matronics.com
> Onderwerp: AeroElectric-List: Re: Subaru z-figure
>
>
>
> Z-19 was produced in cooperation with an individual builder
> for use with his Subaru engine. I've had no conversations with
> suppliers of engine packages although I've offered a collaborative
> effort on several occasions to several such suppliers.
>
> I've not heard from the builder. This was several years ago
> and I'd have to dig around in my e-mails to see if I can locate
> him. As I recall, our several exchanges of Z-19
> iterations ended with him expressing satisfaction with the
> approach. If anyone has some suggestions and/or critical review
> useful for enhancements to the approach, I'd be pleased to
> receive them.
>
> Bob . . .
>
>
>
> >
> >
> >As someone who does not plan to use the EXPBUS in my Eggenfellner
> >installation, I would be most interested in something specific that Bob
> >could put together. There was a lot of talk on the Eggenfellner list
> awhile
> >back about someone designing a replacement for the EXPBUS, but it didnt
> >materialize. I plan to use a combination of modified versions of Bobs
> >existing layouts and a couple of the Hyperion components. Anything that
> >Bob could put together as a complete, professional layout for the
> >Eggenfellner FWF (all-electric, one alternator, dual batteries, with full
> >backup, switchover, and protection) would be just great.
> >brian
> >expecting my STi in just a couple more weeks!
> >http://brian76.mystarband.net/RV-7Ahome.htm
> >
> >
> >-----Original Message-----
> >From: B Tomm [mailto:fvalarm(at)rapidnet.net]
> >To: 'subaruaircraft(at)yahoogroups.com'
> >Subject: RE: [subaruaircraft] Re: CV Report on Ind Mod Failure
> >
> >Gary,
> >
> >Thanks for the thoughtful reply. I'm sure Bob would be more than happy
> to
> >adapt an electrical layout for the EGG package. That is essentially what
> >Z-19 is. The only major mod that I can think of is putting the batteries
> >aft of the baggage (RV7A H6). I have already talked to him about this
> but
> >not finalized the details yet. I'll copy this email to Bob for comment.
> >
> >Bevan
> >
> >-----Original Message-----
> >From: Gary Newsted [SMTP:fcs(at)jlc.net]
> >To: subaruaircraft(at)yahoogroups.com
> >Subject: [subaruaircraft] Re: CV Report on Ind Mod Failure
> >
> >
> >I should point out that it is CV's optional enunciator module that I
> >have trouble with. The EXP is fine for what it does.
> >
> >When I started working on the electrical design, I was given the EXP
> >as a starting point. That is, take this design and make it work for
> >us, improve it where you can, but most importantly, make it
> >consistent. I feel that this has been achieved, and credit goes to
> >many people in this newsgroup for contributing their expertise.
> >
> >The install guide presents an airworthy adaptation of the EXP for
> >Eggenfellner engines, and tries to make the installation clear and
> >simple. If you follow the guide, you will have a modern, airworthy
> >system which is easy to operate and easy for us to diagnose should it
> >ever give you trouble. I occasionally pick on people who deviate
> >from this design, not because the design is perfect, but because I
> >believe consistency is at the very root of the success of
> >Eggenfellner packages.
> >
> >Let's face it, the thing that will bring down a Subaru will be fuel
> >or electrical, so these two systems must be consistent, with lots of
> >eyes reviewing these designs. One failure impacts all of us.
> >
> >Several times we have tossed around the pros and cons
> >of "conventional" electrical designs, of which Aeroelectrics are a
> >good example. I have not pursued this, although others have. In my
> >eyes, conventional designs leave too many doors open which could
> >result in inconsistency and even dangerous installations. If some
> >qualified individual wanted to invest the time and energy into
> >perfecting and thoroughly documenting a conventional design
> >specifically for the Eggenfellner engines, I think Jan would support
> >the effort (in spirit anyway).
> >
> >If you are a long ways away from wiring, don't rush into your
> >decision either. There just might be better things coming soon.
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Subaru z-figure |
>
>Bob,
>
>I've downloaded a whole bunch from your web site, but the Z figures in those
>downloads do not include a Z-19. Could you please give me a steer?
>
>Thanks
This is a pending rev 11 addition. Sneak peek at:
http://www.aeroelectric.com/PPS/Architecture/Zfigs_K_5.pdf
Bob . . .
________________________________________________________________________________
| From: | "Jon Finley" <Jon(at)finleyweb.net> |
| Subject: | Re: Subaru z-figure |
Sort of opportune moment to jump into this thread Ive been trying to find the
time to compose some intelligent questions about a simple electron-dependent-engine
system (Subaru).
After studying the Z diagrams (I've not yet studied these sneak-peak diagrams), I came up came up with the system posted on my website (http://www.finleyweb.net/default.asp?id=131). This was designed and constructed more than a year ago. Since this time Ive learned a lot by lurking here and now understand that my system has a number of weaknesses/problems (which probably means that are more things that I dont even know about yet).
My biggest issue/hurdle is that the relevant Z diagrams seem overly complicated
for my simple system. I do not have a highly complex airplane nor do I have a
difficult mission profile. While I am an IFR pilot, I know that my airplane is
strictly VFR. When I detect an electrical problem, everything in the airplane
is going to be shutdown. The engine keeps running from the battery and I land
(within an hour). I dont NEED a radio, transponder, gauges, five-hour range,
etc... just need the engine to keep running for a bit. I could probably babble
on for a long time about this but my point (really a request) is that I
would really like to see a simple system for a Subaru.
Thanks Bob!
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
Apple Valley, Minnesota
http://www.FinleyWeb.net/Q2Subaru
---------- Original Message ----------------------------------
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Date: Tue, 15 Mar 2005 09:52:31 -0600
>
>
>>
>>Bob,
>>
>>I've downloaded a whole bunch from your web site, but the Z figures in those
>>downloads do not include a Z-19. Could you please give me a steer?
>>
>>Thanks
>
>This is a pending rev 11 addition. Sneak peek at:
>
>http://www.aeroelectric.com/PPS/Architecture/Zfigs_K_5.pdf
>
> Bob . . .
________________________________________________________________________________
| From: | D Wysong <hdwysong(at)gmail.com> |
| Subject: | Re: the ideal OV protection (maybe |
FWIW - Mouser (www.mouser.com) carries the NTE6403 as a "drop in
replacement" for the extinct Motorola MBS499X part(s) if someone is
following the old schematic. The NTE part will cost you $8, though!
D
------------------------
Robert L. Nuckolls, III wrote:
>
>
> B&C did a lifetime buy of the MBS4991 trigger diodes before they disappeared.
>
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Points for discussion OVP//more |
Mickey Coggins wrote:
>
>Hi,
>
>Where does one buy a *new* ND alternator?
>
>Thanks,
>Mickey
>
For anyone new to this thread, ND is Nippon Denso (I hope I spelled that
correctly...), a Japanese brand name on automotive electrical products.
Most automotive parts houses have both new & rebuilt versions on their
shelves. There might be multiple brands available for any particular car
model, so if you are forced to specify a '1979 Belchfire 300' to get the
alternator you want, just open the box & check the label on the
alternator for the correct brand name.
I know this is stating the obvious for some, but 'ND' might be a bit
cryptic for new arrivals.
Charlie
________________________________________________________________________________
| From: | Sean Stephens <schmoboy(at)cox.net> |
| Subject: | StripMaster Wire Strippers |
Which model of Stripmaster wire strippers is recommended? There are so
many model numbers I was getting dizzy trying to pick the right one.
45-1551 by chance?
Also, any recommendations for an online resource with good prices?
Thanks...
Sean
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: the ideal OV protection (maybe |
>
>FWIW - Mouser (www.mouser.com) carries the NTE6403 as a "drop in
>replacement" for the extinct Motorola MBS499X part(s) if someone is
>following the old schematic. The NTE part will cost you $8, though!
Ouch! I think I was paying 0.16 each in thousands for this
part. I'll let the MBS4992's I have go out for $1 each.
Bob . . .
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
FWIW Try http://www.midwestsurplus.net/en-us/dept_30.html for MBS4991 at
$0.25 ea. The ones I got worked fine.
Jim Stone
Jabiru J450
Clearwater FL
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
>
>FWIW Try http://www.midwestsurplus.net/en-us/dept_30.html for MBS4991 at
>$0.25 ea. The ones I got worked fine.
Good find! I'm pleased that there are some still running
in the wild.
For those interested in a DIY project for crowbar OV module
utilizing the MBS4991 trigger diode, the old schematic
and bill of materials has been posted at:
http://www.aeroelectric.com/PPS/DCPwr/OV/OVM-14_mbs4991.pdf
Bob . . .
________________________________________________________________________________
| From: | Sean Stephens <schmoboy(at)cox.net> |
| Subject: | Re: StripMaster Wire Strippers |
Sorry, found this link and was wondering if it is a good price and the
correct model...
<http://www.goodmart.com/products/86241.htm>
Thanks...
Sean Stephens wrote:
> Which model of Stripmaster wire strippers is recommended? There are
> so many model numbers I was getting dizzy trying to pick the right
> one. 45-1551 by chance?
>
> Also, any recommendations for an online resource with good prices?
>
> Thanks...
>
> Sean
>
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | SSRs to control annunciator lights? |
I'm looking for comments on a way to control some annunciator lights.
I've got four Vivisun 20/20 M22885/90 incandescent annunciator lights
that have 28v bulbs. I'm told that 14v bulbs are rare and expensive,
so I'll add a DC-DC voltage converter using a National LM3478 eval
board, as I've got a 14v aircraft. I think I can simply use 14v as
the dim setting, and 28v as the high setting.
The signals that control the lights are all high = ON. I think the
simplest way to sort all this out is to use four relays (or perhaps
solid-state relays - SSRs) to control the ground from the each light.
That way I can use a single feed of 28v or 14v from a ON-ON BRT-DIM
switch and have it feed all four annunciators.
Using four mechanical relays to control the ground for each
annunciator will work, but I wonder if SSRs would provide a smaller,
more reliable solution. I don't know much at all about SSRs though.
My web searching hasn't hit the gold mine yet, so I am looking for
advice.
I'd like recommendations on some sort of 4-channel SSR that would be
reasonably priced, easy to install and robust. Each annunciator will
draw about 0.12a at 28v. Or, is there a better way to control four
annunciators and and feed them 28v or 14v for dimming?
Thanks in advance,
--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "Mark/Micki Phillips" <mphill(at)gcctv.com> |
Anyone have any info on what type of screwdriver or tool that Garmin uses to loosin
the latching mechanism to the tray???
Mark Phillips
WIlliamsville,Illinois
RV-6 Finishing
________________________________________________________________________________
| From: | "Mark/Micki Phillips" <mphill(at)gcctv.com> |
Anyone have any info on what type of screwdriver or tool that Garmin uses to loosin
the latching mechanism to the tray???
Mark Phillips
WIlliamsville,Illinois
RV-6 Finishing
________________________________________________________________________________
| From: | Neil K Clayton <harvey4(at)earthlink.net> |
A 3/32" allen key.
Neil
At 09:28 PM 3/15/2005, you wrote:
>
>
>Anyone have any info on what type of screwdriver or tool that Garmin uses
>to loosin the latching mechanism to the tray???
>Mark Phillips
>WIlliamsville,Illinois
>RV-6 Finishing
>
>
________________________________________________________________________________
| From: | "Stein Bruch" <stein(at)steinair.com> |
It's a small "allen" wrench or hex type wrench.
Cheers,
Stein.
---------- Original Message ----------------------------------
From: "Mark/Micki Phillips" <mphill(at)gcctv.com>
Date: Tue, 15 Mar 2005 20:28:16 -0600
>
>Anyone have any info on what type of screwdriver or tool that Garmin uses to loosin
the latching mechanism to the tray???
>Mark Phillips
>WIlliamsville,Illinois
>RV-6 Finishing
>
>
________________________________________________________________________________
| From: | B Tomm <fvalarm(at)rapidnet.net> |
Stein,
By the way what is the approximate price diff between the GTX-330 and 327?
-----Original Message-----
From: Stein Bruch [SMTP:stein(at)steinair.com]
Subject: Re: AeroElectric-List: GTX-327
It's a small "allen" wrench or hex type wrench.
Cheers,
Stein.
---------- Original Message ----------------------------------
From: "Mark/Micki Phillips" <mphill(at)gcctv.com>
Date: Tue, 15 Mar 2005 20:28:16 -0600
>
>Anyone have any info on what type of screwdriver or tool that Garmin uses to loosin
the latching mechanism to the tray???
>Mark Phillips
>WIlliamsville,Illinois
>RV-6 Finishing
>
>
________________________________________________________________________________
| From: | B Tomm <fvalarm(at)rapidnet.net> |
Stein,
By the way what is the approximate price diff between the GTX-330 and 327?
Sorry to hit send before signing off.
Bevan
RV7A fuse
-----Original Message-----
From: Stein Bruch [SMTP:stein(at)steinair.com]
Subject: Re: AeroElectric-List: GTX-327
It's a small "allen" wrench or hex type wrench.
Cheers,
Stein.
---------- Original Message ----------------------------------
From: "Mark/Micki Phillips" <mphill(at)gcctv.com>
Date: Tue, 15 Mar 2005 20:28:16 -0600
>
>Anyone have any info on what type of screwdriver or tool that Garmin uses to loosin
the latching mechanism to the tray???
>Mark Phillips
>WIlliamsville,Illinois
>RV-6 Finishing
>
>
________________________________________________________________________________
| From: | "Tony Johnson" <tonyjohnson(at)cfl.rr.com> |
| Subject: | Using a 115 volt 400 hz device in a 12 volt airplane |
I have a pitot tube that is wired for a 115 volts at 400 hz. I would like
to use it on my RV8A, which will have a 12 volt system.
I applied 110v house current to the tube, using a dimmer switch set at the
lowest setting. The tube heated up. I was afraid to increase the power to
it.
My plan is to acquire an adjustable resistor, set it for high resistance,
and apply 12volts through it to the tube, probably with a fuse inline
between the resistor and tube.
I would appreciate any input as to how to arrange to use the tube on my 12
volt system.
Tony Johnson
RV8A Orlando
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Sudden overwhelming signal on radio? |
Folks:
I recently installed an ICS-Plus radio in my AA-1. I have been
relatively happy with it, but today on a return flight from Mexico,
while cruising along FD&H at 10.5 about 30 minutes in, it was suddenly
overwhelmed by what sounded to me to be broadband noise. It did not
seem to be alternator dependent, as I switched off the alternator and
changed RPMs with no apparent effect.
The radio has a built in signal strength meter, and it was showing 2-2.5
(of 5) bars with no one transmitting on the frequency. I turned off the
auto squelch and turn the manual almost all the way up and was able to
use the radio. The noise continued and seemed to get worse (up to 3
bars!) as the flight wore on for almost another 40 minutes (about 100
NM). I checked various frequencies and the A/B switch and all gave the
same results.
After landing, I glanced at the signal strength display and it was back
to the normal minimum it shows when the frequency is cold. Turned down
the squelch and all was well. Switched to auto squelch and all stayed
well. Gremlin gone?
Any ideas on this one??
Andy Elliott
N481HY/AA-1(TD,160)/KFFZ
That's "One Hot Yankee"
http://members.cox.net/n481hy/
________________________________________________________________________________
| From: | "Hans Teijgeler" <hans(at)jodel.com> |
| Subject: | Re: Subaru z-figure |
Jon,
Your requirements exactly match mine. Strictly VFR, Subaru engine and tough
luck for ATC, but as soon as my alternator dies the radio will be switched
off, no lights, no strobe, no tpx, no electric flaps, no electric trim, just
the engine to feed from two batteries.
I've ended up with a very simple diagram:
Battery A feeds pump A, computer A and the main bus.
Battery B feeds pump B, computer B and the starter
One alternator tops off both batteries through some diodes
No crossfeeding, no E-bus, no complexity. I know that I am throwing away a
lot of flexibility, I know that a triple failure might shut me down
(alternator, battery A and computer B broken = glider), but I can live with
that. The reduced complexity makes up for that- for me.
Thanks Bob for the preview. The diagram makes a lot of sense if you want to
keep alive more than the engine alone. Like with Jon, it simply is overkill
for my requirements.
Hans
> -----Oorspronkelijk bericht-----
> Van: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> aeroelectric-list-server(at)matronics.com] Namens Jon Finley
> Verzonden: dinsdag 15 maart 2005 17:48
> Aan: aeroelectric-list(at)matronics.com
> Onderwerp: RE: AeroElectric-List: Re: Subaru z-figure
>
>
>
> Sort of opportune moment to jump into this thread Ive been trying to find
> the time to compose some intelligent questions about a simple electron-
> dependent-engine system (Subaru).
>
> After studying the Z diagrams (I've not yet studied these sneak-peak
> diagrams), I came up came up with the system posted on my website
> (http://www.finleyweb.net/default.asp?id=131). This was designed and
> constructed more than a year ago. Since this time Ive learned a lot by
> lurking here and now understand that my system has a number of
> weaknesses/problems (which probably means that are more things that I dont
> even know about yet).
>
> My biggest issue/hurdle is that the relevant Z diagrams seem overly
> complicated for my simple system. I do not have a highly complex airplane
> nor do I have a difficult mission profile. While I am an IFR pilot, I know
> that my airplane is strictly VFR. When I detect an electrical problem,
> everything in the airplane is going to be shutdown. The engine keeps
> running from the battery and I land (within an hour). I dont NEED a
> radio, transponder, gauges, five-hour range, etc... just need the engine
> to keep running for a bit. I could probably babble on for a long time
> about this but my point (really a request) is that I would really like to
> see a simple system for a Subaru.
>
> Thanks Bob!
>
> Jon Finley
> N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
> Apple Valley, Minnesota
> http://www.FinleyWeb.net/Q2Subaru
>
>
> ---------- Original Message ----------------------------------
> From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
> Date: Tue, 15 Mar 2005 09:52:31 -0600
>
>
> >
> >
>
> >>
> >>Bob,
> >>
> >>I've downloaded a whole bunch from your web site, but the Z figures in
> those
> >>downloads do not include a Z-19. Could you please give me a steer?
> >>
> >>Thanks
> >
> >This is a pending rev 11 addition. Sneak peek at:
> >
> >http://www.aeroelectric.com/PPS/Architecture/Zfigs_K_5.pdf
> >
> > Bob . . .
>
>
>
>
>
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Subaru z-figure |
I'm happy to say that the diagram I came up with for my
electrically dependent engine, based on the information
I got from Bob's book, and this list, looks essentially
like Bob's new Z-19. Kind of makes me think that I may
have actually learned something these past few months!
I have a somewhat related question. Could there be any
increase in risk having two batteries run in parallel?
One battery taking out the other under some strange
circumstance?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 Wiring
________________________________________________________________________________
| From: | Jerzy Krasinski <krasinski(at)provalue.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt |
airplane
Tony Johnson wrote:
>
>I have a pitot tube that is wired for a 115 volts at 400 hz. I would like
>to use it on my RV8A, which will have a 12 volt system.
>
>
>I applied 110v house current to the tube, using a dimmer switch set at the
>lowest setting. The tube heated up. I was afraid to increase the power to
>it.
>
>
>My plan is to acquire an adjustable resistor, set it for high resistance,
>and apply 12volts through it to the tube, probably with a fuse inline
>between the resistor and tube.
>
>
>I would appreciate any input as to how to arrange to use the tube on my 12
>volt system.
>
>
>Tony Johnson
>
>RV8A Orlando
>
>
>
>
Tony,
At 110V heater powered from 12V is useless, it will produce roughly 1%
of its rated power. Do not bother with trying to get it working using 12V.
You can power it from one of cheap commercial inverters 12V to
110V/60Hz. The frequency is irrelevant in case of a heater. But check if
the inverter does not make radio interference.
Jerzy
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: StripMaster Wire Strippers |
>
>Sorry, found this link and was wondering if it is a good price and the
>correct model...
>
><http://www.goodmart.com/products/86241.htm>
>
>Thanks...
Yes, this is the benchmark stripper for Tefzel/Teflon insulated
wires. Anything under $150 is probably a good deal. Alternatively,
I have fabricated my own clones by salvaging the dies out of
strippers with broken handles and installing them in Radio Shack
clones of the Ideal Stripmaster handles (about $13.00). You can
buy a new die set from the same company at:
http://www.goodmart.com/products/86079.htm
for about $82 and put them into an RS handle for under $100
total.
You can get "real" Stripmaster handles off ebay. When fitted
with the el-cheeso dies, they go pretty cheap. See:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26229&item=7500103375&rd=1&ssPageName=WDVW
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=66989&item=7500963130&rd=1&ssPageName=WDVW
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=66989&item=7500572228&rd=1&ssPageName=WDVW
Here's an auction on a pair of strippers described to
have type E (tefzel/teflon) dies:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4535940899&category=26436&sspagename=WDVW
But if push comes to the big shove, one can learn to strip Tefzel
wire with a pair of flush cutters . . .
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=66990&item=3880590926&rd=1
See
http://aeroelectric.com/articles/strippers/strippers.html
Bob . . .
________________________________________________________________________________
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
| From: | "Craig P. Steffen" <craig(at)craigsteffen.net> |
> I have a pitot tube that is wired for a 115 volts at 400 hz. I would like
> to use it on my RV8A, which will have a 12 volt system.
Now I'm curious. What power system produces 115 VAC at 400 Hz?
> My plan is to acquire an adjustable resistor, set it for high resistance,
> and apply 12volts through it to the tube, probably with a fuse inline
> between the resistor and tube.
Why don't you just get a heater that's designed to work at 12V?
Dropping the voltage down with a series resistor means that you're
dumping a lot of the power into the resistor, not the heater.
Craig Steffen
--
craig(at)craigsteffen.net
public key available at http://www.craigsteffen.net/GPG/
current goal: use a CueCat scanner to inventory my books
career goal: be the first Vorlon Time Lord
________________________________________________________________________________
| From: | Dj Merrill <deej(at)thayer.dartmouth.edu> |
| Subject: | Re: Sudden overwhelming signal on radio? |
Dr. Andrew Elliott wrote:
> I recently installed an ICS-Plus radio in my AA-1. I have been
> relatively happy with it, but today on a return flight from Mexico,
> while cruising along FD&H at 10.5 about 30 minutes in, it was suddenly
> overwhelmed by what sounded to me to be broadband noise. It did not
> seem to be alternator dependent, as I switched off the alternator and
> changed RPMs with no apparent effect.
Hi Andy,
I was flying through South Carolina the other day, and
for at least a solid 5 minutes I was clearly picking up a
broadcast radio station. My guess is that the frequency I
had on the COM radio was a harmonic of the radio broadcast
frequency, or the internal oscillators of the radio
were picking up the broadcast signal directly. I was at
7500 feet.
If it does not do it all the time my guess is a local
geographic issue - can you try flying over the same place
again with your radio set to the same freq and see
it you can repeat it?
-Dj
--
Dj Merrill
deej(at)thayer.dartmouth.edu
"TSA: Totally Screwing Aviation"
________________________________________________________________________________
| From: | Richard Riley <Richard(at)RILEY.NET> volt airplane |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
volt airplane
airplane
At 07:19 AM 3/16/05, you wrote:
>
>
> > I have a pitot tube that is wired for a 115 volts at 400 hz. I would like
> > to use it on my RV8A, which will have a 12 volt system.
>
>Now I'm curious. What power system produces 115 VAC at 400 Hz?
They're very common in military aircraft.
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
In a message dated 3/16/2005 10:29:35 A.M. Central Standard Time,
Richard(at)RILEY.NET writes:
>
>Now I'm curious. What power system produces 115 VAC at 400 Hz?
They're very common in military aircraft.
Good Morning All,
As long as the subject has been broached, are there any efficient, light
weight, low cost converters available that will supply 115 volt 400 cycle
current from twelve or twenty four volts DC?
The ones we had on the DC-6s and DC-7s must have weighed a ton!
Well, maybe only fifty pounds or so, but way to big for a small airplane.
Anything better been developed in the last sixty years?
I have very nice oscillating beacon that uses that current.
It sure would be nice to be able to drive it from twenty-four volt DC power.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "cgalley" <cgalley(at)qcbc.org> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
They make solid state converters. I have one for a remote compass system.
Very small and weighs very little.
----- Original Message -----
From: <BobsV35B(at)aol.com>
Subject: Re: AeroElectric-List: Using a 115 volt 400 hz device in a 12 volt
airplane
>
>
> In a message dated 3/16/2005 10:29:35 A.M. Central Standard Time,
> Richard(at)RILEY.NET writes:
>
>>
>>Now I'm curious. What power system produces 115 VAC at 400 Hz?
>
> They're very common in military aircraft.
>
>
> Good Morning All,
>
> As long as the subject has been broached, are there any efficient, light
> weight, low cost converters available that will supply 115 volt 400 cycle
> current from twelve or twenty four volts DC?
>
> The ones we had on the DC-6s and DC-7s must have weighed a ton!
>
> Well, maybe only fifty pounds or so, but way to big for a small airplane.
> Anything better been developed in the last sixty years?
>
> I have very nice oscillating beacon that uses that current.
>
> It sure would be nice to be able to drive it from twenty-four volt DC
> power.
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
In a message dated 3/16/2005 11:16:42 A.M. Central Standard Time,
cgalley(at)qcbc.org writes:
They make solid state converters. I have one for a remote compass system.
Very small and weighs very little.
Good Morning Cy,
How much output, how much weight, how much cost and where can it be
purchased!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | rd2(at)evenlink.com.volt.airplane |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
volt airplane
-----snip-----------------
They make solid state converters. I have one for a remote compass system.
Very small and weighs very little.
----snip------------------
They?
Sorry, I may have missed something, or it got somehow truncated. Was there
an URL with the post?
Rumen
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Robert, et al.
Re:
http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
About 5000 years ago the Chinese had remarkable scientific techniques. But
somewhere along the way they decided that an experiment isolated from the
rest of the world was simply not valid, because it was believed that
everything influenced everything else. Ahem....but I digress........maybe.
The White Paper skirts the key issue which is: Why bother using the crowbar
technique when it has been abandoned by the rest of the entire cosmic
universe for systems such as this? I have in my hand the data sheets for the
MC3309X line of Motorola alternator voltage regulator chips (the most recent
of which--MC33099-- contains adaptive logic!...but I digress). Can you guess
what Motorola uses to terminate the field winding when bad things happen?
There are about a hundred bazillion of these in service (and sampling the
product stream to get one is like drinking from a firehose....but I
digress). No crowbars here bubela.
Nobody argues that a crowbar works, it just isn't used anymore because
better methods are available. For those who MUST have a crowbar do it this
way:
http://www.periheliondesign.com/downloads/NOOVP.pdf But unless the system
requirement is to make the whole circuit dead in a wink, nobody does this
anymore.
Now to the White Paper:
1) Cover page is okay except "Over Voltage" should be hyphenated.
"...Comprised of..." is not English.
2) What is this drawing? Nobody has an electrical system as shown. The
Klixon 7274 is the way-fastest part in the series. What is the big diode?
Why not use the AE Crowbar here instead of whatever stand-in we see? [Insert
eight-dozen other quibbles here.] If RAC has a spare TDS210 in the closet
I'd jeeze I'd love to have one. But I digress.....
3) Okay...short attention span. The rest of the report massages the figures
a bit but arrives at the conclusion that maybe 263A or so blasts through the
little 5A Klixon 7274 like a photon torpedo.
Discussion: The Klixon 7274 is not rated for 14.5 V trips of this magnitude.
While it is rated as "Unlimited Amps at 28V", can we therefore assume that
this makes 14.5V a piece of cake? Hardly; from 8-16 volts is a kind of
neverland for electrical contacts---to high for gold and too low for
silver--the voltages/trip characteristics do not scale. The TI/Klixon graphs
show the maximum breaking capacity at 28V is 1000% (10X) rated and 0.10 to
0.40 S. NOT 263/5= 5260% and 15 mS. Assuming we do this anyway--how many
shots is the breaker now good for? 3? 10? 1000? Who knows?
Discussion: The alternator shown....oops, who stole the darned alternator?
The alternator does something very bad when crowbarred. It puffs up its
little cheeks and chest preparing to spew out more electrons, but the next
second, loadless, it is disappointed and does the Technicolor yawn off the
back porch. This is my explanation for Load Dump which is better than
Paul's, but I digress....The alternators contribution to the OVP episode is
not strictly a DC matter.
Anyway, I suggest that the test setup in not a good representation of what
is happening in the system.
Finally....whew....we get back to the main question---Why bother hammering
the electrical system with a crowbar when you don't have to? Let's have some
common sense.
With great respect...and sorry about the humor...it's those pills the doctor
makes me take.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"The beginning of the end is marked by replacement of experience and common
sense with policy and procedures."
-- R. L. Nuckolls III
________________________________________________________________________________
| From: | "cgalley" <cgalley(at)qcbc.org> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
I may have spoken too soon. Went back into my shop and pulled it out. It is
by Aircraft instrument and Development. It was purchased for $37 about 1980
by a friend who gave it to me.
Label says P/N 23-1100-4amps, input 14 VDC Output 26 VAC 400 hz 10 VA
Aircraft Inst. & Dev. Inc
317 E Lewis, Wichita, Kansas
The box is 2x1.5x2.5inches which is a far cry from the big war surplus
inverters. for the compass system.
It isn't what you want but I have a feeling that there is a box that will.
I found this same Box listed at http://www.mcico.com/pdf/md26.pdf with a
drawing.
Cy Galley - Chair,
AirVenture Emergency Aircraft Repair
A Service Project of Chapter 75
EAA Safety Programs Editor - TC
EAA Sport Pilot
----- Original Message -----
From: <BobsV35B(at)aol.com>
Subject: Re: AeroElectric-List: Using a 115 volt 400 hz device in a 12 volt
airplane
>
>
> In a message dated 3/16/2005 11:16:42 A.M. Central Standard Time,
> cgalley(at)qcbc.org writes:
>
> They make solid state converters. I have one for a remote compass
> system.
> Very small and weighs very little.
>
>
> Good Morning Cy,
>
> How much output, how much weight, how much cost and where can it be
> purchased!
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
>
________________________________________________________________________________
| From: | "cgalley" <cgalley(at)qcbc.org> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
Found the price $374 for the little box I have.
----- Original Message -----
From: <BobsV35B(at)aol.com>
Subject: Re: AeroElectric-List: Using a 115 volt 400 hz device in a 12 volt
airplane
>
>
> In a message dated 3/16/2005 11:16:42 A.M. Central Standard Time,
> cgalley(at)qcbc.org writes:
>
> They make solid state converters. I have one for a remote compass
> system.
> Very small and weighs very little.
>
>
> Good Morning Cy,
>
> How much output, how much weight, how much cost and where can it be
> purchased!
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt airplane |
In a message dated 3/16/2005 4:03:20 P.M. Central Standard Time,
cgalley(at)qcbc.org writes:
--> AeroElectric-List message posted by: "cgalley"
Found the price $374 for the little box I have.
Good Afternoon Cy,
When I noted that the company was Mid Continent Instruments, I expected such
a price.
Back when your unit was purchased, MCI was a good company to deal with.
They have now degenerated into the same mode as Grimes Electric. They stick it
to us as bad as anyone in the industry. We sure need some competition in
that arena.
Very sad to see that happen
Thanks for all the information.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | Robert McCallum <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt |
airplane
Tony;
When discussing heaters, the frequency of the power source has no
effect on the power (amount of heat produced) Directly powering your 115
Volt 400Hz heater from your household power will produce very close to
the designed quantity of heat because you are applying the design
voltage. The heat produced by any specific heater varies from the
designed wattage by the square of the applied voltage. In simple terms
if you halve the applied voltage you will get 1/4 of the design wattage.
If you double the applied voltage you will produce 4 times the design
wattage. (and burn out the heater) In your case trying to run a 115 volt
heater on 12 volts is applying approximately 1/10 the design voltage and
you will get 1/100th of the design wattage. In other words almost
nothing, certainly not enough to accomplish anything. Adding a resistor
as you suggest only reduces the voltage (current) even more, further
reducing the already negligible heat you are producing. The most
convenient way to do what you are asking is to buy an inverter for
producing 120 volt AC power from a 12 volt battery and using that to
power your heater. Make sure that the wattage of your inverter is at
least as great or greater than the heater wattage. Bear in mind , as
someone else pointed, out that some inverters may introduce significant
RF noise in your radios or create annoying noise in you intercom. A 12
volt heater is much easier. Hope this sheds some light.
Bob McC
Tony Johnson wrote:
>
>I have a pitot tube that is wired for a 115 volts at 400 hz. I would like
>to use it on my RV8A, which will have a 12 volt system.
>
>
>I applied 110v house current to the tube, using a dimmer switch set at the
>lowest setting. The tube heated up. I was afraid to increase the power to
>it.
>
>
>My plan is to acquire an adjustable resistor, set it for high resistance,
>and apply 12volts through it to the tube, probably with a fuse inline
>between the resistor and tube.
>
>
>I would appreciate any input as to how to arrange to use the tube on my 12
>volt system.
>
>
>Tony Johnson
>
>RV8A Orlando
>
>
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "George Braly" <gwbraly(at)gami.com> |
The Motorola part is a nice automotive part.
But it won't work at 28 volts.
And it leaves the system vulnerable to a couple of single point failure modes that
are unacceptable for aviation purposes, in my judgment.
And the very high rate di/dt of the mosfet that it uses for the PWM of the field
generates some ferociously noisy harmonics in the alternator B+ circuit.
Regards, George
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Eric M. Jones
Subject: AeroElectric-List: Re: White Paper on Crowbar OV Protection
Robert, et al.
Re:
http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
About 5000 years ago the Chinese had remarkable scientific techniques. But
somewhere along the way they decided that an experiment isolated from the
rest of the world was simply not valid, because it was believed that
everything influenced everything else. Ahem....but I digress........maybe.
The White Paper skirts the key issue which is: Why bother using the crowbar
technique when it has been abandoned by the rest of the entire cosmic
universe for systems such as this? I have in my hand the data sheets for the
MC3309X line of Motorola alternator voltage regulator chips (the most recent
of which--MC33099-- contains adaptive logic!...but I digress). Can you guess
what Motorola uses to terminate the field winding when bad things happen?
There are about a hundred bazillion of these in service (and sampling the
product stream to get one is like drinking from a firehose....but I
digress). No crowbars here bubela.
Nobody argues that a crowbar works, it just isn't used anymore because
better methods are available. For those who MUST have a crowbar do it this
way:
http://www.periheliondesign.com/downloads/NOOVP.pdf But unless the system
requirement is to make the whole circuit dead in a wink, nobody does this
anymore.
Now to the White Paper:
1) Cover page is okay except "Over Voltage" should be hyphenated.
"...Comprised of..." is not English.
2) What is this drawing? Nobody has an electrical system as shown. The
Klixon 7274 is the way-fastest part in the series. What is the big diode?
Why not use the AE Crowbar here instead of whatever stand-in we see? [Insert
eight-dozen other quibbles here.] If RAC has a spare TDS210 in the closet
I'd jeeze I'd love to have one. But I digress.....
3) Okay...short attention span. The rest of the report massages the figures
a bit but arrives at the conclusion that maybe 263A or so blasts through the
little 5A Klixon 7274 like a photon torpedo.
Discussion: The Klixon 7274 is not rated for 14.5 V trips of this magnitude.
While it is rated as "Unlimited Amps at 28V", can we therefore assume that
this makes 14.5V a piece of cake? Hardly; from 8-16 volts is a kind of
neverland for electrical contacts---to high for gold and too low for
silver--the voltages/trip characteristics do not scale. The TI/Klixon graphs
show the maximum breaking capacity at 28V is 1000% (10X) rated and 0.10 to
0.40 S. NOT 263/5= 5260% and 15 mS. Assuming we do this anyway--how many
shots is the breaker now good for? 3? 10? 1000? Who knows?
Discussion: The alternator shown....oops, who stole the darned alternator?
The alternator does something very bad when crowbarred. It puffs up its
little cheeks and chest preparing to spew out more electrons, but the next
second, loadless, it is disappointed and does the Technicolor yawn off the
back porch. This is my explanation for Load Dump which is better than
Paul's, but I digress....The alternators contribution to the OVP episode is
not strictly a DC matter.
Anyway, I suggest that the test setup in not a good representation of what
is happening in the system.
Finally....whew....we get back to the main question---Why bother hammering
the electrical system with a crowbar when you don't have to? Let's have some
common sense.
With great respect...and sorry about the humor...it's those pills the doctor
makes me take.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"The beginning of the end is marked by replacement of experience and common
sense with policy and procedures."
-- R. L. Nuckolls III
---
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Protection |
| Subject: | Re: White Paper on Crowbar OV |
Protection
Protection
>
>Robert, et al.
>
>Re:
>http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
>
>About 5000 years ago the Chinese had remarkable scientific techniques. But
>somewhere along the way they decided that an experiment isolated from the
>rest of the world was simply not valid, because it was believed that
>everything influenced everything else. Ahem....but I digress........maybe.
If the experiment is too complex, then the results are not repeatable
due to outside influences and does not illuminate a simple-idea. The
standard for the Coulomb (ampere-second) is defined in a manner
that anyone with the appropriate equipment can repeat the experiment
and obtain the same results. My wife is an expert at complex experiments
but it takes a really agile program to do statistical analysis on
data and to predict cause and effect with reasonable certainty. I'll
suggest we avoid statistics for this study and concentrate on the
repeatable physics.
>The White Paper skirts the key issue which is: Why bother using the crowbar
>technique when it has been abandoned by the rest of the entire cosmic
>universe for systems such as this?
I haven't skirted anything. The white paper makes no recommendations
nor does it reflect anyone's opinions.
> I have in my hand the data sheets for the
>MC3309X line of Motorola alternator voltage regulator chips (the most recent
>of which--MC33099-- contains adaptive logic!...but I digress). Can you guess
>what Motorola uses to terminate the field winding when bad things happen?
>There are about a hundred bazillion of these in service (and sampling the
>product stream to get one is like drinking from a firehose....but I
>digress). No crowbars here bubela.
To my knowledge crowbar ov protection has never been used in
the automotive world. Further, as far as I know, I was the first
to introduce it to aviation when it was the ONLY system that would
qualify on the turbine Bonanza out of a field of several dozen
commonly available OV relays of the time.
>Nobody argues that a crowbar works, it just isn't used anymore because
>better methods are available. For those who MUST have a crowbar do it this
>way:
>http://www.periheliondesign.com/downloads/NOOVP.pdf But unless the system
>requirement is to make the whole circuit dead in a wink, nobody does this
>anymore.
Haven't even addressed requirements yet. That's getting way ahead
of the study at hand.
>Now to the White Paper:
>
>1) Cover page is okay except "Over Voltage" should be hyphenated.
>"...Comprised of..." is not English.
>2) What is this drawing? Nobody has an electrical system as shown. The
>Klixon 7274 is the way-fastest part in the series.
The experiment is not intended to duplicate anyone's electrical
system. Is it your suggestion that the experiment be repeated with
another circuit breaker? 7274 series is all I have in my junk
box. You pick a number, I'll go find one.
> What is the big diode?
MCR69 SCR
>Why not use the AE Crowbar here instead of whatever stand-in we see? [Insert
>eight-dozen other quibbles here.]
The purpose of this experiment was to deduce exactly what the
measured data shows. Peak currents, delay times and influences on
bus voltage when subjected to those current. I mentioned
at the end of the paper that we'll go explore the dynamic characteristics
of the design under study. That's a separate experiment/analysis
and will probably use the full-up OVM-14
> If RAC has a spare TDS210 in the closet
>I'd jeeze I'd love to have one. But I digress.....
RAC doesn't own own as far as I know. It's part of my personally
owned professional tools.
>3) Okay...short attention span. The rest of the report massages the figures
>a bit but arrives at the conclusion that maybe 263A or so blasts through the
>little 5A Klixon 7274 like a photon torpedo.
Yes . . . so? If the 7274 were sitting on someone's aircraft breaker
panel and the downstream wire gets faulted, is there any guarantee
that the fault current won't be 263 or more or less? This isn't
germane to the discussion.
You've missed the point of the paper. The "stand in" is indeed an
MCR69 device, exactly as used in several hundreds of OVM-14 modules
produced over the past 10 years or so.
>Discussion: The Klixon 7274 is not rated for 14.5 V trips of this magnitude.
Perhaps you're privy to some limitations on the 7274 that I am not.
It's indeed rated at 28v which accounts for 95% of its application.
Where do we read that stresses for 14v operation depart markedly
from those cited for 28v. I can call the guys at Eaton/Cuttler-Hammer
tomorrow if we're needing any documentation. Can you enlighten me?
>While it is rated as "Unlimited Amps at 28V", can we therefore assume that
>this makes 14.5V a piece of cake? Hardly; from 8-16 volts is a kind of
>neverland for electrical contacts---to high for gold and too low for
>silver--the voltages/trip characteristics do not scale.
I wouldn't suggest that they do. Assuming that a builder does
use a 7274 Klixon in his system. What is the risk? Is the breaker
at risk of failing to open? Failing to re-close after an OV event?
Reduction in service life from the published 2500 cycles at
30VDC resistive? If it were reduced to perhaps 100 cycles, should
I care? In any case, the experiment wasn't about breaker selection.
Pick another breaker and I'll go find one.
> The TI/Klixon graphs
>show the maximum breaking capacity at 28V is 1000% (10X) rated and 0.10 to
>0.40 S. NOT 263/5= 5260% and 15 mS. Assuming we do this anyway--how many
>shots is the breaker now good for? 3? 10? 1000? Who knows?
I assume nothing about the 7274. It's a breaker that came from
my junkbox to investigate the values measured and cited. If you
have other measurements you'd like to see, please state them
and the suggested test setup and I'll go see what I get.
Again, you're missing the point of the experiment. I belive I've
read numbers cited that crowbar currents as high as 700 amps
have been measured. My question is: what was the setup so that
I might go to my workbench and measure those currents myself?
I've read numbers citing time delays far longer than anything
I've seen in about 15 years of producing this system. I'm not
arguing with those numbers, only trying to deduce how they were
acquired. I've often suggested that the repeatable experiment
is the Holy Grail of quantification and understanding. To date,
I've seen lots of numbers which mystify me. Soooo . . . an hour
or so at the workbench produced the data cited to date. More
is yet to come.
>Discussion: The alternator shown....oops, who stole the darned alternator?
>The alternator does something very bad when crowbarred. It puffs up its
>little cheeks and chest preparing to spew out more electrons, but the next
>second, loadless, it is disappointed and does the Technicolor yawn off the
>back porch. This is my explanation for Load Dump which is better than
>Paul's, but I digress....The alternators contribution to the OVP episode is
>not strictly a DC matter.
I believe I understand but I'm not convinced that my understanding
matches yours. We spoke of some testing to be done and data
to be shared but to date, pronouncements are made
on suitability or lack of suitability-to-task with little or
no foundation in repeatable experiments. I did a lot
of this same work 20 years ago for Beech and again 5 years later
for B&C. I'm repeating it again with the intent of laying out
exactly what I've done, the measurements I've acquired and
my interpretation of their significance. I've acquired an alternator
test stand and hope to pick it up next week sometime when my
son lets me have my truck back.
>Anyway, I suggest that the test setup in not a good representation of what
>is happening in the system.
The test setup IS a representation of exactly what it shows and no more.
It describes a study and analysis of source impedances and current
limitations based on a choice of materials that would normally be
EXPECTED to produce the highest crowbar currents. Admittedly this
investigation
is a small part of the whole. But I find it useful to investigate one
feature at a time. Recall my penchant for boiling system operations
down to their rudimentary components . . . simple ideas that stand alone
and are easily understood and INVARIABLE. Then we'll start stacking
them together to see if the system performance is meeting objectives.
>Finally....whew....we get back to the main question---Why bother hammering
>the electrical system with a crowbar when you don't have to? Let's have some
>common sense.
Define "hammer" . . . Please use quantified terminology. You seem to
object to deliberate development of a current pulse designed to open
a breaker under circumstances it is DESIGNED to handle. The experiment
thus far is intended to DEMONSTRATE that currents developed the typical
system are modest compared to values cited without benefit of a supporting
experiment. Further, they are deduced to not place any other part of the
system at risk in that bus voltage excursions are no worse than for
energizing a landing gear pump. It's was intended to INVESTIGATE the
elusive 700A pulse . . . or even a 300A pulse for that matter. The only
time I saw a crowbar event of 300A was on Bill's 24v test stand with
very atypical wiring lengths. The bench test setup I wrote about
demonstrated a crowbar event of less than 200 amps.
>With great respect...and sorry about the humor...it's those pills the doctor
>makes me take.
Understand. Had to change my blood pressure medicine several times
before I found one I can live with and still does the job. My invitation
is to join in analysis of the data presented thus far. I'll be pleased to
explore the features cited in a manner that can be repeated by anyone else
at any time. This isn't a contest or an attempt to persuade anyone of
anything. Let's go get the data and understand the physics that drives it.
If you have suggestions to make for further testing in Phase I, I'd be
pleased to respond. After all the numbers are in, only then does anyone
have all the information needed to participate in their own decision making
process.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> volt airplane |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
volt airplane
volt airplane
AC power systems are the wave of the future for most airplanes above
15,000 pounds. Our Horizon uses a wild frequency AC system and I'm
specifying some AC generation equipment onto a much smaller airplane.
Our smaller Hawkers have big inverters.
Now, if one wants to talk about WIRE WEIGHT reduction, high voltage
AC is the way to get it. 208V 3-phase provides 115V from any leg
to ground for small appliances. But when run through a rectifier,
the 208 3-phase produces 270 VDC to run brushless DC motors. An
air conditioner system that draws 200A at 28v draws only 20A
at 270 VDC. This current is easily carried on a twisted trio of
16 AWG wires where it took a pair of 2AWG wires before. Further,
the ship's airframe is NOT used for grounding on the high power
3-phase systems so that no ground loop noises are injected to
other systems.
Inverters for developing 400Hz AC come in ALL sizes ranging from
25 watt devices weighing perhaps 8 ounces and used to drive
an instrument up to 1500 watt hogs that weigh in around 40
pounds and have BIG cooling fans on them. The very best way
to generate lots of AC is from an engine driven alternator.
400 Hz AC power has been around since before WWII on larger
aircraft for a variety of task but until 1950's was not used
for whole-aircraft power. I think our Horizon has two
transformer/rectifiers that develop about 50A each to handle
ALL DC requirements. Everything else runs from the AC power.
The Beechjet has two 400A generators to run it's DC only
systems.
Bob . . .
________________________________________________________________________________
| From: | "Dan O'Brien" <limadelta(at)gmail.com> |
| Subject: | OV protection debate |
In the OV protection debate, you engineers are losing your
non-engineer OBAM readers. The problems are jargon, which is not
easily deciphered by non-engineers, and abstractions for which the
connection to the real world problem of building a reliable, failure
tolerant system, is not immediately clear. It's too expensive for us
non-engineers to spend the time trying to decipher the jargon and draw
the connections.
Is the audience here supposed to be physicists and electronics
engineers, or the OBAM community (which consists of doctors,
carpenters, lawyers, economists, mechanics, managers, burger flippers,
etc.)? Many readers of this list won't benefit if the idea can't be
made simple enough for OBAMers to translate into their projects.
Just a comment, FWIW.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: OV protection debate |
>
>In the OV protection debate, you engineers are losing your
>non-engineer OBAM readers. The problems are jargon, which is not
>easily deciphered by non-engineers, and abstractions for which the
>connection to the real world problem of building a reliable, failure
>tolerant system, is not immediately clear. It's too expensive for us
>non-engineers to spend the time trying to decipher the jargon and draw
>the connections.
>Is the audience here supposed to be physicists and electronics
>engineers, or the OBAM community (which consists of doctors,
>carpenters, lawyers, economists, mechanics, managers, burger flippers,
>etc.)? Many readers of this list won't benefit if the idea can't be
>made simple enough for OBAMers to translate into their projects.
I'm well aware that the vast majority of folks who visit
here are MOST interested in knowing what parts to buy and
how to wire them up. However, when debates are mounted in
support of or against any particular technique or philosophy,
it's of vital importance that those who offer opinions do
so with a full and common understanding of the physics and
philosophies being debated.
Would you rather that parties interested in such conversation
cloistered their efforts in hidden spaces until they're ready
to emerge with conclusions? That's what our politicians do.
That's what marketing folks who craft advertisements do. The
LAST thing they want is for their target audience to understand
what has transpired.
>Just a comment, FWIW.
Point well taken and acknowledged. The remedy is at hand.
Please use your delete key as appropriate to your personal
interests and needs for utilizing this list.
Bob . . .
________________________________________________________________________________
| From: | "Vern W." <vernw(at)ev1.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Give 'em hell, Bob :-)
One thing though: I AM interested in a follow up to where it was found
(anecdotally for the moment) that alternators sold by Van's seem to fail
when installed with the crowbar OV protection circuit and don't otherwise.
If true, then something is obviously going on that needs to be looked at a
bit closer. Any ideas on that?
Vern
----- Original Message -----
From: "Robert L. Nuckolls, III Protection" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Re: White Paper on Crowbar OV Protection
Protection
>
>
> >
> >Robert, et al.
> >
> >Re:
>
>http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Pap
er.pdf
> >
> >About 5000 years ago the Chinese had remarkable scientific techniques.
But
> >somewhere along the way they decided that an experiment isolated from the
> >rest of the world was simply not valid, because it was believed that
> >everything influenced everything else. Ahem....but I
digress........maybe.
>
> If the experiment is too complex, then the results are not repeatable
> due to outside influences and does not illuminate a simple-idea. The
> standard for the Coulomb (ampere-second) is defined in a manner
> that anyone with the appropriate equipment can repeat the experiment
> and obtain the same results. My wife is an expert at complex
experiments
> but it takes a really agile program to do statistical analysis on
> data and to predict cause and effect with reasonable certainty. I'll
> suggest we avoid statistics for this study and concentrate on the
> repeatable physics.
>
>
> >The White Paper skirts the key issue which is: Why bother using the
crowbar
> >technique when it has been abandoned by the rest of the entire cosmic
> >universe for systems such as this?
>
> I haven't skirted anything. The white paper makes no recommendations
> nor does it reflect anyone's opinions.
>
> > I have in my hand the data sheets for the
> >MC3309X line of Motorola alternator voltage regulator chips (the most
recent
> >of which--MC33099-- contains adaptive logic!...but I digress). Can you
guess
> >what Motorola uses to terminate the field winding when bad things happen?
> >There are about a hundred bazillion of these in service (and sampling the
> >product stream to get one is like drinking from a firehose....but I
> >digress). No crowbars here bubela.
>
> To my knowledge crowbar ov protection has never been used in
> the automotive world. Further, as far as I know, I was the first
> to introduce it to aviation when it was the ONLY system that would
> qualify on the turbine Bonanza out of a field of several dozen
> commonly available OV relays of the time.
>
> >Nobody argues that a crowbar works, it just isn't used anymore because
> >better methods are available. For those who MUST have a crowbar do it
this
> >way:
> >http://www.periheliondesign.com/downloads/NOOVP.pdf But unless the
system
> >requirement is to make the whole circuit dead in a wink, nobody does this
> >anymore.
>
>
> Haven't even addressed requirements yet. That's getting way ahead
> of the study at hand.
>
> >Now to the White Paper:
> >
> >1) Cover page is okay except "Over Voltage" should be hyphenated.
> >"...Comprised of..." is not English.
> >2) What is this drawing? Nobody has an electrical system as shown. The
> >Klixon 7274 is the way-fastest part in the series.
>
> The experiment is not intended to duplicate anyone's electrical
> system. Is it your suggestion that the experiment be repeated with
> another circuit breaker? 7274 series is all I have in my junk
> box. You pick a number, I'll go find one.
>
> > What is the big diode?
>
> MCR69 SCR
>
> >Why not use the AE Crowbar here instead of whatever stand-in we see?
[Insert
> >eight-dozen other quibbles here.]
>
> The purpose of this experiment was to deduce exactly what the
> measured data shows. Peak currents, delay times and influences on
> bus voltage when subjected to those current. I mentioned
> at the end of the paper that we'll go explore the dynamic
characteristics
> of the design under study. That's a separate experiment/analysis
> and will probably use the full-up OVM-14
>
>
> > If RAC has a spare TDS210 in the closet
> >I'd jeeze I'd love to have one. But I digress.....
>
> RAC doesn't own own as far as I know. It's part of my personally
> owned professional tools.
>
> >3) Okay...short attention span. The rest of the report massages the
figures
> >a bit but arrives at the conclusion that maybe 263A or so blasts through
the
> >little 5A Klixon 7274 like a photon torpedo.
>
> Yes . . . so? If the 7274 were sitting on someone's aircraft breaker
> panel and the downstream wire gets faulted, is there any guarantee
> that the fault current won't be 263 or more or less? This isn't
> germane to the discussion.
>
> You've missed the point of the paper. The "stand in" is indeed an
> MCR69 device, exactly as used in several hundreds of OVM-14 modules
> produced over the past 10 years or so.
>
>
> >Discussion: The Klixon 7274 is not rated for 14.5 V trips of this
magnitude.
>
> Perhaps you're privy to some limitations on the 7274 that I am not.
> It's indeed rated at 28v which accounts for 95% of its application.
> Where do we read that stresses for 14v operation depart markedly
> from those cited for 28v. I can call the guys at Eaton/Cuttler-Hammer
> tomorrow if we're needing any documentation. Can you enlighten me?
>
> >While it is rated as "Unlimited Amps at 28V", can we therefore assume
that
> >this makes 14.5V a piece of cake? Hardly; from 8-16 volts is a kind of
> >neverland for electrical contacts---to high for gold and too low for
> >silver--the voltages/trip characteristics do not scale.
>
> I wouldn't suggest that they do. Assuming that a builder does
> use a 7274 Klixon in his system. What is the risk? Is the breaker
> at risk of failing to open? Failing to re-close after an OV event?
> Reduction in service life from the published 2500 cycles at
> 30VDC resistive? If it were reduced to perhaps 100 cycles, should
> I care? In any case, the experiment wasn't about breaker selection.
> Pick another breaker and I'll go find one.
>
> > The TI/Klixon graphs
> >show the maximum breaking capacity at 28V is 1000% (10X) rated and 0.10
to
> >0.40 S. NOT 263/5= 5260% and 15 mS. Assuming we do this anyway--how many
> >shots is the breaker now good for? 3? 10? 1000? Who knows?
>
> I assume nothing about the 7274. It's a breaker that came from
> my junkbox to investigate the values measured and cited. If you
> have other measurements you'd like to see, please state them
> and the suggested test setup and I'll go see what I get.
>
> Again, you're missing the point of the experiment. I belive I've
> read numbers cited that crowbar currents as high as 700 amps
> have been measured. My question is: what was the setup so that
> I might go to my workbench and measure those currents myself?
>
> I've read numbers citing time delays far longer than anything
> I've seen in about 15 years of producing this system. I'm not
> arguing with those numbers, only trying to deduce how they were
> acquired. I've often suggested that the repeatable experiment
> is the Holy Grail of quantification and understanding. To date,
> I've seen lots of numbers which mystify me. Soooo . . . an hour
> or so at the workbench produced the data cited to date. More
> is yet to come.
>
>
> >Discussion: The alternator shown....oops, who stole the darned
alternator?
> >The alternator does something very bad when crowbarred. It puffs up its
> >little cheeks and chest preparing to spew out more electrons, but the
next
> >second, loadless, it is disappointed and does the Technicolor yawn off
the
> >back porch. This is my explanation for Load Dump which is better than
> >Paul's, but I digress....The alternators contribution to the OVP episode
is
> >not strictly a DC matter.
>
> I believe I understand but I'm not convinced that my understanding
> matches yours. We spoke of some testing to be done and data
> to be shared but to date, pronouncements are made
> on suitability or lack of suitability-to-task with little or
> no foundation in repeatable experiments. I did a lot
> of this same work 20 years ago for Beech and again 5 years later
> for B&C. I'm repeating it again with the intent of laying out
> exactly what I've done, the measurements I've acquired and
> my interpretation of their significance. I've acquired an alternator
> test stand and hope to pick it up next week sometime when my
> son lets me have my truck back.
>
>
> >Anyway, I suggest that the test setup in not a good representation of
what
> >is happening in the system.
>
> The test setup IS a representation of exactly what it shows and no
more.
> It describes a study and analysis of source impedances and current
> limitations based on a choice of materials that would normally be
> EXPECTED to produce the highest crowbar currents. Admittedly this
> investigation
> is a small part of the whole. But I find it useful to investigate one
> feature at a time. Recall my penchant for boiling system operations
> down to their rudimentary components . . . simple ideas that stand
alone
> and are easily understood and INVARIABLE. Then we'll start stacking
> them together to see if the system performance is meeting objectives.
>
>
> >Finally....whew....we get back to the main question---Why bother
hammering
> >the electrical system with a crowbar when you don't have to? Let's have
some
> >common sense.
>
> Define "hammer" . . . Please use quantified terminology. You seem to
> object to deliberate development of a current pulse designed to open
> a breaker under circumstances it is DESIGNED to handle. The experiment
> thus far is intended to DEMONSTRATE that currents developed the typical
> system are modest compared to values cited without benefit of a
supporting
> experiment. Further, they are deduced to not place any other part of
the
> system at risk in that bus voltage excursions are no worse than for
> energizing a landing gear pump. It's was intended to INVESTIGATE the
> elusive 700A pulse . . . or even a 300A pulse for that matter. The only
> time I saw a crowbar event of 300A was on Bill's 24v test stand with
> very atypical wiring lengths. The bench test setup I wrote about
> demonstrated a crowbar event of less than 200 amps.
>
>
> >With great respect...and sorry about the humor...it's those pills the
doctor
> >makes me take.
>
> Understand. Had to change my blood pressure medicine several times
> before I found one I can live with and still does the job. My
invitation
> is to join in analysis of the data presented thus far. I'll be pleased
to
> explore the features cited in a manner that can be repeated by anyone
else
> at any time. This isn't a contest or an attempt to persuade anyone of
> anything. Let's go get the data and understand the physics that drives
it.
> If you have suggestions to make for further testing in Phase I, I'd be
> pleased to respond. After all the numbers are in, only then does anyone
> have all the information needed to participate in their own decision
making
> process.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Thank you Bob
It is nice to see some numbers based on an understandable real experiment.
I've got 22awg wire that is a bit longer with more connections and a 2
amp CB in my aircraft over voltage circuit and I'm very comfortable with
it so far. I look
forward to the next installment.
Ken
Robert L. Nuckolls, III wrote:
>
>
>See:
>
>http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
>
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Apparently they tell the control circuitry to shut off the Mosfet gate.
http://www.ortodoxism.ro/datasheets/motorola/MC33092A.pdf
Presumaby this is "state of the installed art" but it seems that there
are still
failure modes in the Mosfet (the switch that turns field current on and
off) and the control circuitry that apparently render the load dump and
over voltage control ineffective. It is nice to have an idea of what
might be there, even if we can't quantify the risks or tell what is
actually in a specific alternator.
It would be nice to replace my B lead contactor with a solid state
device but I need to see the numbers and test results, not just the
theory, before I'm willing to consider replacing or eliminating the
contactor. So far I'm still quite happy with the crowbar overvoltage
protection but I'm following the discussion.
Ken
Eric M. Jones wrote:
>-->snip
>
>I have in my hand the data sheets for the
>MC3309X line of Motorola alternator voltage regulator chips (the most
recent
>of which--MC33099-- contains adaptive logic!...but I digress). Can you
guess
>what Motorola uses to terminate the field winding when bad things happen?
>
>
________________________________________________________________________________
| Subject: | Audio panel for single seat Yak |
| From: | "Dee L. Conger" <dee(at)ansatainc.com> |
Hi Bob,
I'm currently working on an electrical system for my Yak 50, which is a
single seat Russian airplane. The plane will be equipped with an SL30
Nav/Com, an SL70 Transponder and a Blue Mountain EFIS sport - powered by
a B&C pad-mounted alternator (for M14P). I'm not quite sure what to do
about an audio panel - since I have only one Nav/Com, there doesn't seem
to be a real need for one, expect for mixing in music and maybe for the
marker beacon receiver. I plan on using a stereo headset and would like
to be able to pipe in MP3s.
Would your isolation amp be a good solution? Or, can you recommend a
small, single place audio panel?
Thanks,
Dee L. Conger
(858) 754-3010 Direct
This email and any attachments thereto may contain private,
confidential, and privileged material for the sole use of the intended
recipient. Any review, copying, or distribution of this email (or any
attachments thereto) by others is strictly prohibited. If you are not
the intended recipient, please contact the sender immediately and
permanently delete the original and any copies of this email and any
attachments thereto.
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: OV protection debate |
One of my favorite quotes. I used it a lot when I was
slinging code in a previous life. Another one, when
asked if it could get done faster if I had some help,
was "Adding a second woman to the job won't make the
baby come in 4.5 months."
Please keep the debate going - I'm enjoying it, and learning
things along the way.
Mickey
> Einstein suggested things should be made as simple as possible...but
> no simpler. ...
--
Mickey Coggins
http://www.rv8.ch/
#82007 Wiring
________________________________________________________________________________
| From: | rv-9a-online <rv-9a-online(at)telus.net> |
| Subject: | Re: Audio panel for single seat Yak |
I'll jump in here.
For a single-seat aircraft, you don't need an audio panel or an
isolation amplifier.
All you need to do is connect your audio sources to the headphone audio
bus and wire the headset mic to the SL-30 directly.
To connect to the audio bus, the SL-30 *must* have a series resistor
(anything from 300 to 600 ohms should work). Connect the SL-30 audio to
one end of the resistor, and the connect the other end of the resistor
to the common audio bus. To this bus, connect any other audio sources
such as your marker beacon receiver, audio alarms and of course, your
headphones.
For an external audio source, such as an MP3 player, you will need to
wire series resistors in the left and right audio channels as well,
connecting them both to the common audio bus. This will give you mono
music in the headset. Stereo audio is more involved, but follows the
same principal.
Follow the resistor procedure for any low-impedance audio source. It
won't hurt to have them in place for all audio bus connections (except
your headphones), but it's easier to wire without them.
I hope this is clear. If not, I can send a diagram.
Vern Little
Dee L. Conger wrote:
>
>Hi Bob,
>
>
>I'm currently working on an electrical system for my Yak 50, which is a
>single seat Russian airplane. The plane will be equipped with an SL30
>Nav/Com, an SL70 Transponder and a Blue Mountain EFIS sport - powered by
>a B&C pad-mounted alternator (for M14P). I'm not quite sure what to do
>about an audio panel - since I have only one Nav/Com, there doesn't seem
>to be a real need for one, expect for mixing in music and maybe for the
>marker beacon receiver. I plan on using a stereo headset and would like
>to be able to pipe in MP3s.
>
>
>Would your isolation amp be a good solution? Or, can you recommend a
>small, single place audio panel?
>
>
>Thanks,
>
>
>Dee L. Conger
>(858) 754-3010 Direct
>
>This email and any attachments thereto may contain private,
>confidential, and privileged material for the sole use of the intended
>recipient. Any review, copying, or distribution of this email (or any
>attachments thereto) by others is strictly prohibited. If you are not
>the intended recipient, please contact the sender immediately and
>permanently delete the original and any copies of this email and any
>attachments thereto.
>
>
>
>
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
Say - does anyone know what the wiring diagram for an SL40 is - concerning the
37 pin connector? The wiring diagrams I have only list pinouts for the 15 pin
connector.
Thanks,
John
________________________________________________________________________________
| From: | Walter Tondu <walter(at)tondu.com> |
On 03/17 12:06, John Tvedte wrote:
>
> Say - does anyone know what the wiring diagram for an SL40 is - concerning the
37 pin connector? The wiring diagrams I have only list pinouts for the 15
pin connector.
I'm pretty sure the 37 pin connector is only used on the SL30 Nav/Com.
It's unused on the SL40.
Here's the link for the SL30.
http://www.garmin.com/manuals/SL30Nav_Comm_InstallationManual.pdf
--
Walter Tondu
http://www.rv7-a.com
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Audio panel for single seat Yak |
Although Vern is correct, here is another perspective.
Get a good stereo audio panel (maybe a Garmin 340 or PS Engineering unit)
and save the hassle. It will cost you a few $$ but then everything is nicely
packaged and will accommodate expansion.
We have the SL30 radio and I did something similar to what Vern is
recommending. Later we decided to add a marker beacon to the already added
stereo music in to the intercom. An audio panel from the beginning would
have been less work.
James
p.s. You might also get better "squelch" control for the Yak noise as well
from an integrated unit.
| -----Original Message-----
| From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
| aeroelectric-list-server(at)matronics.com] On Behalf Of rv-9a-online
| Sent: Thursday, March 17, 2005 12:58 PM
| To: aeroelectric-list(at)matronics.com
| Subject: Re: AeroElectric-List: Audio panel for single seat Yak
|
| online(at)telus.net>
|
| I'll jump in here.
|
| For a single-seat aircraft, you don't need an audio panel or an
| isolation amplifier.
|
| All you need to do is connect your audio sources to the headphone audio
| bus and wire the headset mic to the SL-30 directly.
|
| To connect to the audio bus, the SL-30 *must* have a series resistor
| (anything from 300 to 600 ohms should work). Connect the SL-30 audio to
| one end of the resistor, and the connect the other end of the resistor
| to the common audio bus. To this bus, connect any other audio sources
| such as your marker beacon receiver, audio alarms and of course, your
| headphones.
|
| For an external audio source, such as an MP3 player, you will need to
| wire series resistors in the left and right audio channels as well,
| connecting them both to the common audio bus. This will give you mono
| music in the headset. Stereo audio is more involved, but follows the
| same principal.
|
| Follow the resistor procedure for any low-impedance audio source. It
| won't hurt to have them in place for all audio bus connections (except
| your headphones), but it's easier to wire without them.
|
| I hope this is clear. If not, I can send a diagram.
|
| Vern Little
|
|
{SNIP}
________________________________________________________________________________
| Subject: | Audio panel for single seat Yak |
| From: | "Dee L. Conger" <dee(at)ansatainc.com> |
Thanks - this is very helpful. What is the purpose of the resistors?
Also, I would strongly prefer to retain stereo music - maybe this is
where the isolation amp would be helpful?
Dee L. Conger
(858) 754-3010 Direct
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
rv-9a-online
Subject: Re: AeroElectric-List: Audio panel for single seat Yak
I'll jump in here.
For a single-seat aircraft, you don't need an audio panel or an
isolation amplifier.
All you need to do is connect your audio sources to the headphone audio
bus and wire the headset mic to the SL-30 directly.
To connect to the audio bus, the SL-30 *must* have a series resistor
(anything from 300 to 600 ohms should work). Connect the SL-30 audio to
one end of the resistor, and the connect the other end of the resistor
to the common audio bus. To this bus, connect any other audio sources
such as your marker beacon receiver, audio alarms and of course, your
headphones.
For an external audio source, such as an MP3 player, you will need to
wire series resistors in the left and right audio channels as well,
connecting them both to the common audio bus. This will give you mono
music in the headset. Stereo audio is more involved, but follows the
same principal.
Follow the resistor procedure for any low-impedance audio source. It
won't hurt to have them in place for all audio bus connections (except
your headphones), but it's easier to wire without them.
I hope this is clear. If not, I can send a diagram.
Vern Little
Dee L. Conger wrote:
>
>Hi Bob,
>
>
>I'm currently working on an electrical system for my Yak 50, which is a
>single seat Russian airplane. The plane will be equipped with an SL30
>Nav/Com, an SL70 Transponder and a Blue Mountain EFIS sport - powered
by
>a B&C pad-mounted alternator (for M14P). I'm not quite sure what to do
>about an audio panel - since I have only one Nav/Com, there doesn't
seem
>to be a real need for one, expect for mixing in music and maybe for the
>marker beacon receiver. I plan on using a stereo headset and would
like
>to be able to pipe in MP3s.
>
>
>Would your isolation amp be a good solution? Or, can you recommend a
>small, single place audio panel?
>
>
>Thanks,
>
>
>Dee L. Conger
>(858) 754-3010 Direct
>
>This email and any attachments thereto may contain private,
>confidential, and privileged material for the sole use of the intended
>recipient. Any review, copying, or distribution of this email (or any
>attachments thereto) by others is strictly prohibited. If you are not
>the intended recipient, please contact the sender immediately and
>permanently delete the original and any copies of this email and any
>attachments thereto.
>
>
>
>
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
The SL-40 doesn't have a 37 pin connector.
Dick Tasker
John Tvedte wrote:
>
>Say - does anyone know what the wiring diagram for an SL40 is - concerning the
37 pin connector? The wiring diagrams I have only list pinouts for the 15 pin
connector.
>
>Thanks,
>
>John
>
>
________________________________________________________________________________
| From: | "John Danielson" <johnd(at)wlcwyo.com> |
The SL-40 has a 15 pin connector.
Go to http://www.rv7-a.com/manuals/SL40Comm_InstallationManual.pdf for
an installation manual.
John L. Danielson
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Richard Tasker
Subject: Re: AeroElectric-List: Apollo SL40
The SL-40 doesn't have a 37 pin connector.
Dick Tasker
John Tvedte wrote:
<JohnT@comp-sol.com>
>
>Say - does anyone know what the wiring diagram for an SL40 is -
concerning the 37 pin connector? The wiring diagrams I have only list
pinouts for the 15 pin connector.
>
>Thanks,
>
>John
>
>
________________________________________________________________________________
| From: | rv-9a-online <rv-9a-online(at)telus.net> |
| Subject: | Re: Audio panel for single seat Yak |
To get stereo music, do the following:
Make two audio buses: L & R
All of your monophonic sources are connected to both of the L & R buses
with series resistors (on connected to L and the other to R).
.
All of your stereophonic sources are connected left channel to L and
right channel to R with individual series resistors.
As for using an isolation amp... you have a simple panel and a very
simple audio system. An isolation amp like Bob supplies on his website
could be used, but isn't really necessary. A full audio panel is
overkill, in my opinion.
Vern
Dee L. Conger wrote:
>
>Thanks - this is very helpful. What is the purpose of the resistors?
>Also, I would strongly prefer to retain stereo music - maybe this is
>where the isolation amp would be helpful?
>
>Dee L. Conger
>(858) 754-3010 Direct
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
>rv-9a-online
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: Audio panel for single seat Yak
>
>
>
>I'll jump in here.
>
>For a single-seat aircraft, you don't need an audio panel or an
>isolation amplifier.
>
>All you need to do is connect your audio sources to the headphone audio
>bus and wire the headset mic to the SL-30 directly.
>
>To connect to the audio bus, the SL-30 *must* have a series resistor
>(anything from 300 to 600 ohms should work). Connect the SL-30 audio to
>
>one end of the resistor, and the connect the other end of the resistor
>to the common audio bus. To this bus, connect any other audio sources
>such as your marker beacon receiver, audio alarms and of course, your
>headphones.
>
>For an external audio source, such as an MP3 player, you will need to
>wire series resistors in the left and right audio channels as well,
>connecting them both to the common audio bus. This will give you mono
>music in the headset. Stereo audio is more involved, but follows the
>same principal.
>
>Follow the resistor procedure for any low-impedance audio source. It
>won't hurt to have them in place for all audio bus connections (except
>your headphones), but it's easier to wire without them.
>
>I hope this is clear. If not, I can send a diagram.
>
>Vern Little
>
>
>Dee L. Conger wrote:
>
>
>
>>
>>
>
>
>
>>Hi Bob,
>>
>>
>>I'm currently working on an electrical system for my Yak 50, which is a
>>single seat Russian airplane. The plane will be equipped with an SL30
>>Nav/Com, an SL70 Transponder and a Blue Mountain EFIS sport - powered
>>
>>
>by
>
>
>>a B&C pad-mounted alternator (for M14P). I'm not quite sure what to do
>>about an audio panel - since I have only one Nav/Com, there doesn't
>>
>>
>seem
>
>
>>to be a real need for one, expect for mixing in music and maybe for the
>>marker beacon receiver. I plan on using a stereo headset and would
>>
>>
>like
>
>
>>to be able to pipe in MP3s.
>>
>>
>>Would your isolation amp be a good solution? Or, can you recommend a
>>small, single place audio panel?
>>
>>
>>Thanks,
>>
>>
>>Dee L. Conger
>>(858) 754-3010 Direct
>>
>>This email and any attachments thereto may contain private,
>>confidential, and privileged material for the sole use of the intended
>>recipient. Any review, copying, or distribution of this email (or any
>>attachments thereto) by others is strictly prohibited. If you are not
>>the intended recipient, please contact the sender immediately and
>>permanently delete the original and any copies of this email and any
>>attachments thereto.
>>
>>
>>
>>
>>
>>
>
>
>
>
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Vern W. wrote:
> One thing though: I AM interested in a follow up to where it was found
> (anecdotally for the moment) that alternators sold by Van's seem to fail
> when installed with the crowbar OV protection circuit and don't otherwise.
> If true, then something is obviously going on that needs to be looked at a
> bit closer. Any ideas on that?
I don't know anything about the failures that have been reported, but
the issue does raise some questions before I would point to the OV
protection:
What were the symptoms of the failure? Would the failure have been
detected without OV protection?
If the failure is being blamed on the OVP, presumably the OVP has
tripped at some point. What caused the trip? Doesn't that indicate a
problem before the OVP tripped? If you had a problem with the OVP
repeatedly tripping, you would be likely to investigate the problem, and
an alternator/regulator problem is a likely culprit.
Would the fault be detected at all in an aircraft without OV protection?
I could imagine that if the only problem was a slightly high voltage, it
could go for a long time without being detected, or considered serious
enough to fix.
If, on the other hand, the problem was that the alternator failed to
charge after an OVP trip, and there isn't a no-charge problem on
aircraft without the OVP, the evidence does point to a problem related
to the OVP.
I just read back through a few of the previous messages...
Paul Messinger said "100% of the failed alternators were the result of
the OVP whether it was a crow bar device or a device that simply opened
the "B" lead."
If a device that simply opens the B lead is enough to damage the
alternator, it doesn't sound like the real reason is the OVP module
(although it is possible it could make a problem more likely). It
suggests to me that these alternators should not be disconnected at all
once running, and if you want the ability to do that maybe they are not
suitable. Of the thousands of aircraft flying without failures, how many
have tested what happens if the alternator is disconnected?
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Robert L. Nuckolls, III wrote:
> See:
>
> http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
I have a couple of queries...
If I am understanding it correctly, you make the comment that the
alternator output is reduced when the SCR fires, because the field
voltage is reduced to the voltage across the SCR, about 2 volts.
However, doesn't the internally regulated alternator supply the field
voltage internally, which is why reducing the (external) field voltage
to 0 doesn't shut off the alternator? I wouldn't be surprised if there
was a diode in the field supply to ensure that the alternator could not
supply current through the field terminal, in which case shorting this
circuit shouldn't have an effect on the internal field supply at all.
I would imagine that the internal field supply paths would be shorter
and lower resistance than the paths through the bus, so the field
voltage is likely to be at least as high as the bus voltage, possibly
higher. Do we know how much field voltage internally regulated
alternators actually require to produce full output? I imagine this
could be lower than 12V.
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi...
Are you new to the list?
Your questions have been discussed at length in the recent past.
You have access to the easily searchable archive by clicking on one of the
links in the bottom of the message.
http://www.matronics.com/archives
By the way, who are you?
Regards,
Matt-
VE N34RD, C150 N714BK
>
>
> Robert L. Nuckolls, III wrote:
>
>> See:
>>
>> http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
>
> I have a couple of queries...
>
> If I am understanding it correctly, you make the comment that the
> alternator output is reduced when the SCR fires, because the field
> voltage is reduced to the voltage across the SCR, about 2 volts.
>
> However, doesn't the internally regulated alternator supply the field
> voltage internally, which is why reducing the (external) field voltage
> to 0 doesn't shut off the alternator? I wouldn't be surprised if there
> was a diode in the field supply to ensure that the alternator could not
> supply current through the field terminal, in which case shorting this
> circuit shouldn't have an effect on the internal field supply at all.
>
> I would imagine that the internal field supply paths would be shorter
> and lower resistance than the paths through the bus, so the field
> voltage is likely to be at least as high as the bus voltage, possibly
> higher. Do we know how much field voltage internally regulated
> alternators actually require to produce full output? I imagine this
> could be lower than 12V.
>
>
________________________________________________________________________________
| From: | james freeman <flyeyes(at)mac.com> |
| Subject: | Re: Audio panel for single seat Yak |
Here's yet another perspective ;-D
I doubt you'll find a need in the future for a marker beacon receiver
in a Yak 50. In fact, I would call the SL30 overkill. do you really
need VOR/glideslope?. All of the SL series comms are great radios,
with essentially the functionality of two comms and an audio panel
built in. Since you don't need an intercom, why not get one of the
"Muse" gizmos (I think Lightspeed sells these) to put stereo directly
into the headset. In fact, I have seen newer stereo headsets with
their own input jacks in the earcups. This would be cheaper and
easier, and give you better sound (stereo).
FWIW
James Freeman
On Mar 17, 2005, at 12:38 PM, James E. Clark wrote:
>
>
> Although Vern is correct, here is another perspective.
>
> Get a good stereo audio panel (maybe a Garmin 340 or PS Engineering
> unit)
> and save the hassle. It will cost you a few $$ but then everything is
> nicely
> packaged and will accommodate expansion.
>
> We have the SL30 radio and I did something similar to what Vern is
> recommending. Later we decided to add a marker beacon to the already
> added
> stereo music in to the intercom. An audio panel from the beginning
> would
> have been less work.
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Matt Prather wrote:
> Hi...
>
> Are you new to the list?
>
> Your questions have been discussed at length in the recent past.
>
> You have access to the easily searchable archive by clicking on one of the
> links in the bottom of the message.
>
> http://www.matronics.com/archives
>
> By the way, who are you?
Hi,
I have been lurking on the list for a while, reading and learning but
not posting. I'm sorry if I was supposed to introduce myself before posting.
I understand that the issues have been discussed at length, but have
they been resolved? As I understand it Paul says that when the B-lead is
disconnected the alternator is producing full output due to the low bus
voltage, but Bob is saying it is not capable at that point because the
field voltage is very low. I'm just trying to ask a question to help me
understand which is correct.
Who am I? A builder in Australia, building a Rans S6S. It will have a
Rotax, so the issue with the Vans alternators is academic for me, but
Bob's suggested OVP is similar even if the regulator is not.
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Andrew Rowley wrote:
>
>Robert L. Nuckolls, III wrote:
>
>>See:
>>
>>http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
>>
>>
>
>I have a couple of queries...
>
>If I am understanding it correctly, you make the comment that the
>alternator output is reduced when the SCR fires, because the field
>voltage is reduced to the voltage across the SCR, about 2 volts.
>
>However, doesn't the internally regulated alternator supply the field
>voltage internally, which is why reducing the (external) field voltage
>to 0 doesn't shut off the alternator? I wouldn't be surprised if there
>was a diode in the field supply to ensure that the alternator could not
>supply current through the field terminal, in which case shorting this
>circuit shouldn't have an effect on the internal field supply at all.
>
>
Some do, some don't. Some fellows are using alternators that date back
to at least the mid 70's.
Some will start without a turn on signal. Some won't. The spec for the
control chip that I mentioned this morning said that 2 volts would turn
it on but IIRC it wasn't guaranteed to turn off until the control
terminal was pulled below a half volt. It is reasonable to guess that
the crowbar may turn off some internally regulated alternator fields but
I wouldn't count on it.
>I would imagine that the internal field supply paths would be shorter
>and lower resistance than the paths through the bus, so the field
>voltage is likely to be at least as high as the bus voltage, possibly
>higher. Do we know how much field voltage internally regulated
>alternators actually require to produce full output? I imagine this
>could be lower than 12V.
>
>
>
These regulators rapidly switch the field on and off. So the voltage is
cycling nominally between 0 and 12 volts. At low rpm it may be a
constant 12 volts and perhaps flow 5 amps to command high output
current. At high rpm, I believe the field may only need to be on for a
short period between each off pulse to command high output. The average
current may be only an amp or so. This is known as a small duty cycle.
So you are correct that it is possible to get high output at fairly low
field voltage if the control circuit has failed on continuously. With so
many different designs I think the only sure way to shut these things
off is to disconnect the alternator (disconnect the B lead) unless
someone does a lot of testing with a specific alternator.
Ken
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 volt |
airplane
400 hertz magnetic devices such as transformers are much smaller and
lighter than 60 Hz devices for the same power.
Ken
Pat Hatch wrote:
>
>Bob,
>
>Just out of curiosity, how and why did the 400 Hz convention come about for
>airplanes? Since power is not dependent on frequency (I think), I'm curious
>about the other advantages of going to the higher frequencies. I seem to
>recall the formula for power is P=VI.
>
>Pat Hatch
>
>
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hello (I am guessing) Andrew,
I apologize if I sounded frosty. No introductions necessary. I just like to
poke fun at people when they don't sign their emails in any way. Maybe a
silly hangup on my part.
I do believe your questions have been answered in the archive. Maybe
someone else will re-answer them.
Regards,
Matt-
VE N34RD
>
>
> Matt Prather wrote:
>
>> Hi...
>>
>> Are you new to the list?
>>
>> Your questions have been discussed at length in the recent past.
>>
>> You have access to the easily searchable archive by clicking on one of
>> the links in the bottom of the message.
>>
>> http://www.matronics.com/archives
>>
>> By the way, who are you?
>
> Hi,
>
> I have been lurking on the list for a while, reading and learning but
> not posting. I'm sorry if I was supposed to introduce myself before
> posting.
>
> I understand that the issues have been discussed at length, but have
> they been resolved? As I understand it Paul says that when the B-lead is
> disconnected the alternator is producing full output due to the low bus
> voltage, but Bob is saying it is not capable at that point because the
> field voltage is very low. I'm just trying to ask a question to help me
> understand which is correct.
>
> Who am I? A builder in Australia, building a Rans S6S. It will have a
> Rotax, so the issue with the Vans alternators is academic for me, but
> Bob's suggested OVP is similar even if the regulator is not.
>
>
________________________________________________________________________________
| From: | James Freeman <flyeyes(at)mac.com> |
| Subject: | Re: Audio panel for single seat Yak |
On Mar 17, 2005, at 7:19 PM, james freeman wrote:
>
>
> Here's yet another perspective ;-D
And here is a link which might be helpful:
http://www.avionicswest.com/muse.html#Muse
________________________________________________________________________________
| Subject: | Audio panel for single seat Yak |
| From: | "Dee L. Conger" <dee(at)ansatainc.com> |
Thanks for the ideas - I agree about the need for marker beacon. However, my Yak
50 will be IFR capable, which will come in handy in San Diego where we often
have overcast mornings. My new panel has a Blue Mountain EFIS Sport hooked
up to the SL30 - should work quite well. I'm also installing the EDM-930, which
JPI promises will be 9 cylinder capable shortly. I estimate that the weight
savings alone of this new panel w/ B&C alternator will approach 100 Lbs in
the Yak - the Russian stuff is VERY heavy.
________________________________
From: owner-aeroelectric-list-server(at)matronics.com on behalf of james freeman
Subject: Re: AeroElectric-List: Audio panel for single seat Yak
Here's yet another perspective ;-D
I doubt you'll find a need in the future for a marker beacon receiver
in a Yak 50. In fact, I would call the SL30 overkill. do you really
need VOR/glideslope?. All of the SL series comms are great radios,
with essentially the functionality of two comms and an audio panel
built in. Since you don't need an intercom, why not get one of the
"Muse" gizmos (I think Lightspeed sells these) to put stereo directly
into the headset. In fact, I have seen newer stereo headsets with
their own input jacks in the earcups. This would be cheaper and
easier, and give you better sound (stereo).
FWIW
James Freeman
On Mar 17, 2005, at 12:38 PM, James E. Clark wrote:
>
>
> Although Vern is correct, here is another perspective.
>
> Get a good stereo audio panel (maybe a Garmin 340 or PS Engineering
> unit)
> and save the hassle. It will cost you a few $$ but then everything is
> nicely
> packaged and will accommodate expansion.
>
> We have the SL30 radio and I did something similar to what Vern is
> recommending. Later we decided to add a marker beacon to the already
> added
> stereo music in to the intercom. An audio panel from the beginning
> would
> have been less work.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> volt airplane |
| Subject: | Using a 115 volt 400 hz device in a 12 |
volt airplane
volt airplane
>
>Bob,
>
>Just out of curiosity, how and why did the 400 Hz convention come about for
>airplanes? Since power is not dependent on frequency (I think), I'm curious
>about the other advantages of going to the higher frequencies. I seem to
>recall the formula for power is P=VI.
Power isn't but MAGNETICS are. A 100VA transformer for 60Hz weights
almost exactly 6 times as much as one for 400Hz. This is why you can
get so much from the modern small alternators. They put more poles on
stators and rotors and spin them faster. Internal operating frequency
goes up and watts/pound come down. Since the advent of more efficient
magnetic materials, some wild frequency AC systems in aircraft as high
as 800 Hz.
A power transformer in your computer's power supply may be something
on the order of 1.5" in diameter and about that high. It will weigh
perhaps 4 ounces yet handles the AC power conditioning job for 300
watts of output. It operates in the 20,0000 - 60,000 Hz range.
Bob . . .
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Audio panel for single seat Yak |
This too is true.
Before the SL30 + Marker Beacon, we had an SL40. I have flown planes with
the SL40 and once you get it setup right, it is a great radio.
I assumed, based on his question that he had already decided on the SL30 +
Mkr Bcn and maybe even had them already in anticipation of IFR work.
Given that he is single seat, it also simplifies it to the point of your
recommendation ("Muse gizmo") being quite workable.
Another James
p.s. I bet he did not expect such a wide diversity of opinion on such a
simple matter. :-)
| -----Original Message-----
| From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
| aeroelectric-list-server(at)matronics.com] On Behalf Of james freeman
| Sent: Thursday, March 17, 2005 8:20 PM
| To: aeroelectric-list(at)matronics.com
| Subject: Re: AeroElectric-List: Audio panel for single seat Yak
|
|
| Here's yet another perspective ;-D
|
| I doubt you'll find a need in the future for a marker beacon receiver
| in a Yak 50. In fact, I would call the SL30 overkill. do you really
| need VOR/glideslope?. All of the SL series comms are great radios,
| with essentially the functionality of two comms and an audio panel
| built in. Since you don't need an intercom, why not get one of the
| "Muse" gizmos (I think Lightspeed sells these) to put stereo directly
| into the headset. In fact, I have seen newer stereo headsets with
| their own input jacks in the earcups. This would be cheaper and
| easier, and give you better sound (stereo).
|
| FWIW
|
| James Freeman
|
|
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Matt Prather wrote:
> Hello (I am guessing) Andrew,
>
> I apologize if I sounded frosty. No introductions necessary. I just like to
> poke fun at people when they don't sign their emails in any way. Maybe a
> silly hangup on my part.
>
> I do believe your questions have been answered in the archive. Maybe
> someone else will re-answer them.
OK, fair enough :-) I have changed email address and email program a few
times, and use different addresses for regular email and various lists,
so I guess my sig got lost along the way. You should still be able to
see my name in the From: field though?
I was trying to contribute to the current debate, but maybe it has all
been covered in the past. That's the nature of the internet though - and
one advantage of rehashing old information is that new people learn
stuff they didn't even know they should be asking about :-)
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: White Paper on Crowbar OV Protection |
In a message dated 3/18/2005 2:58:24 A.M. Central Standard Time,
arowley(at)ncable.net.au writes:
You should still be able to
see my name in the From: field though?
Good Morning Andrew,
Unfortunately, the name doesn't come through with all programs. It did on
this message, but not the others.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
All this talk about OV protection reminds me of a question I had way back
that's never been answered. It goes something like this: If we assume the
battery can be modeled by a voltage source in series with its internal
resistance the behavior should be quite simple. We're sitting there with
the battery fully charged and say I want to instantly draw 60 amps out of
the battery. The voltage should drop according to the internal resistance -
let's say it drops 1 volt. Let's instead that I suddenly push 60 amps of
current into the battery. How high does the voltage go? If the model is
correct it will rise 1 volt. As I understand batteries it will then start
to generate gas and the bubbles will increase the internal resistance,
allowing the voltage to start rising, eventually producing destructive
events. Right or wrong? Of course, the magic 60 amps of current going into
the battery is caused by a failed voltage regulator and a 60-amp alternator.
I've read comments that in the case of a sudden 60 amps going into the
battery the voltage will rise earth-destroying values in milliseconds. That
doesn't make sense to me. If that were true then a load dump from a
fully-charging alternator would also be destructive and I think a 60-amp
load dump (when connected to a good battery) will result in a very low
voltage spike, I'll bet less than 1 volt. Unfortunately, the only 60-amp
power supplies I have are not current-regulated so I can't run an experiment
on a real battery. I would like to see a voltage vs time plot of the
battery voltage when 60 amps is applied to a fully charged battery. I have
yet to see such a thing. Somehow I have trouble with the concept that you
can put 5 amps into a battery getting 13.5 volts, but at some higher current
the voltage instantly goes north, like the battery went to an open circuit.
As a side question: I ended up buying an alternator and a B&C regulator
with internal OV protection. A friend that is experienced in aerospace
reliability instantly asked, "you mean that the OV circuitry is integral
with the regulator that it is supposed to be monitoring?" I can only assume
that the OV circuitry is physically separated from the VR circuitry even
though it is in the same box?
Gary Casey
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
Slightly off topic. I have an 18v cordless screwdriver with a spare
battery. My battery charger has crapped out. More specifically, the 21v,
500ma transformer that supports the charger has gone out. Does anybody
have a source for such a transformer? Otherwise I'm looking at buying
another screwdriver just to get a charger.
Charlie Brame
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | Matt Jurotich <mjurotich(at)hst.nasa.gov> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
Bob
Please enlighten us. Wild frequency means?
Matthew M. Jurotich
e-mail mail to:
phone : 301-286-5919
________________________________________________________________________________
| From: | "Vern W." <vernw(at)ev1.net> |
I hope someone can steer me in a better direction with this one because I've searched
the archives, and while there's a reference or two, I don't find any definitive
answers:
To satisfy IFR requirements using both a Garmin 300XL GPS/Comm and SL-30 Nav/Comm,
I need to have an annunciator. No problem so far, but what I don't get
is that the MD41-1454 annunciator made for the 300XL costs almost $1600! I'd
like to think one of the inventive type in this group has come up with a way to
do this without spending almost half the cost of the 300XL itself.
Has anyone yet come up with a schematic to do the same thing?
Vern
________________________________________________________________________________
| From: | "John Danielson" <johnd(at)wlcwyo.com> |
Look on E-bay
John L. Danielson
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Charlie Brame
Subject: AeroElectric-List: 21V Transformer
Slightly off topic. I have an 18v cordless screwdriver with a spare
battery. My battery charger has crapped out. More specifically, the 21v,
500ma transformer that supports the charger has gone out. Does anybody
have a source for such a transformer? Otherwise I'm looking at buying
another screwdriver just to get a charger.
Charlie Brame
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | Jim Oke <wjoke(at)shaw.ca> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
An AC generator/alternator that is driven by an engine that varies in speed
will provide an output that varies in frequency in some way with engine
speed. Thus the expression "wild" frequency AC. "Tame" or "fixed" frequency
AC would be carefully regulated to a particular frequency, usually 400
hertz.
Onboard AC applications such as heating prop blades or windscreens don't
much care what frequency the AC power arrives at. However, most instrument
systems do so often a separate 400 Hz inverter is installed to provide a
reliable source of "tame" AC power.
Jim Oke
Wpg., MB
RV-6A OBAM
----- Original Message -----
From: "Matt Jurotich" <mjurotich(at)hst.nasa.gov>
Subject: Re: AeroElectric-List: Using a 115 volt 400 hz device in a 12
>
>
> Bob
>
> Please enlighten us. Wild frequency means?
>
> Matthew M. Jurotich
>
> e-mail mail to:
> phone : 301-286-5919
>
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
Bob will probably chime in with a more thorough explanation but in the
meantime this may suffice...
Heavy iron traditionally uses a constant speed drive (CSD) transmission
to keep the alternator speed and frequency constant at 400 Hz. If you
leave out the CSD and direct drive the alternator, then the frequency
will vary with engine speed and be "wild". Since a turbine usually idles
at 50% or more of full power accessory drive rpm, then the frequency
can double from idle to full power. A three phase AC motor would of
course also double its speed when the AC frequency is doubled. In some
cases designing for that, or using DC motors, is presumably
cheaper/lighter/more reliable than using a CSD.
Ken
Matt Jurotich wrote:
>
>Bob
>
>Please enlighten us. Wild frequency means?
>
>Matthew M. Jurotich
>
>e-mail mail to:
>phone : 301-286-5919
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: GPS Annunciator |
In a message dated 3/18/2005 9:08:12 A.M. Central Standard Time,
vernw(at)ev1.net writes:
To satisfy IFR requirements using both a Garmin 300XL GPS/Comm and SL-30
Nav/Comm, I need to have an annunciator.
Good Morning Vern,
I am not completely familiar with the Garmin 300XL, but for the vast
majority of IFR boxes, the need for an annunciator is dependent on the location
of
the panel unit.
If your panel unit meets the requirements for inclusion in the pilots normal
scan, no annunciator is required.
However, I totally agree with your assessment of the horrendous costs of the
annunciator units. Back when Mid Continent Instruments had some
competition, their CDIs and annunciators cost about one third of what they now
ask.
Once MCI cornered the market, their prices doubled in one stroke and have been
creeping higher ever since.
MCI is no longer one of the good guys.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hello Andrew,
I must have needed a good night of sleep.. I was dealing with a lot of what
seemed like dumb questions at work yesterday. Let me try this again.
From a design standpoint, an internally regulated alternator where
we don't have positive control of field current suggests the use of a B-lead
contactor. I believe field current (instead of voltage) is more important in
terms of controlling alternator output. Alternators work by magneto dynamics
as much as anything else. The field current generates a magnetic field (!).
I'll digress..
Many builders are using off-the-shelf/out-of-the-junkyard parts. They don't
have any guarantee of what the behavior of a given device will be, much less
what the internal design details are. With this in mind, to get fault
tolerance, it's
good to use a design method which makes conservative assumptions about
the performance of each device.
For instance, make an educated guess about how you think your
alternator/regulator system works. If you suspect that you won't be able to
positively control field current (Andrew's concern), design the system so
that unregulated field current won't hurt you. In this case, as has been
discussed,
the ocurrence of an overvoltage event should cause whatever installed Over
Voltage Protectection circuitry to disconnect the alternator from the bus by
opening the contacts on the B-lead relay.
If however, you are privy to the design details of a particular internal
regulator
circuit and are confident that, for instance, lowering the current through
the
control lead will tame it's output, maybe you don't need any other form of
bus
protection.
Mr Nuckolls' recent whitepaper is an analysis of the electrical performance
and behavior of a crowbar system. It talks mostly about what the voltage
and \
current on the bus are when the Crobar is thrown on the line. The whitepaper
was in response to recent discussion about these dynamics. It isn't a
treatise
on the universal applicability of such a system. I don't think it makes
an comment about what type of alternator/regulator system it is most
applicable to.
Your question is about the use of an alternator/regulator system where there
is some doubt about controlling alternator output via the systems control
lead.
In this case, a crowbar, by itself, certainly is not adequate protection
for other
devices on the bus.
I hope that helps.
Regards,
Matt-
VE N34RD, C150 N714BK
> Hi...
>
> Are you new to the list?
>
> Your questions have been discussed at length in the recent past.
>
> You have access to the easily searchable archive by clicking on one of
> the links in the bottom of the message.
>
> http://www.matronics.com/archives
>
> By the way, who are you?
>
> Regards,
>
> Matt-
> VE N34RD, C150 N714BK
>
>>
>>
>> Robert L. Nuckolls, III wrote:
>>
>>> See:
>>>
>>> http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
>>
>> I have a couple of queries...
>>
>> If I am understanding it correctly, you make the comment that the
>> alternator output is reduced when the SCR fires, because the field
>> voltage is reduced to the voltage across the SCR, about 2 volts.
>>
>> However, doesn't the internally regulated alternator supply the field
>> voltage internally, which is why reducing the (external) field voltage
>> to 0 doesn't shut off the alternator? I wouldn't be surprised if there
>> was a diode in the field supply to ensure that the alternator could
>> not supply current through the field terminal, in which case shorting
>> this circuit shouldn't have an effect on the internal field supply at
>> all.
>>
>> I would imagine that the internal field supply paths would be shorter
>> and lower resistance than the paths through the bus, so the field
>> voltage is likely to be at least as high as the bus voltage, possibly
>> higher. Do we know how much field voltage internally regulated
>> alternators actually require to produce full output? I imagine this
>> could be lower than 12V.
>>
>>
>> http://www.matronics.com/search
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
Vern,
I'm not sure why the built-in functions described in the user manual for
the 300XL wouldn't be sufficient.
http://www.garmin.com/manuals/GNC300XLTSO_PilotsGuide.pdf and search
"annunciator" seems to indicate a lot of capability.
You might want to check out "Annunciator" (AK-950) at Southeast
Aerospace. I see that Paul Lee is using one in his progect
(http://www.abri.com/sq2000/19.html). For spec's see
http://www.ameri-king.com/gps_accessories.html.
Jim Stone
Jabiru J450.
________________________________________________________________________________
| From: | "Vern W." <vernw(at)ev1.net> |
| Subject: | Re: GPS Annunciator |
Jim,
An annunciator may not be needed if the 300XL is the only Nav attached
to a Nav head, but in my case, I'm going to be using the 300XL along with
the SL-30 and run them both to the GRT EFIS for Nav and HSI indication.
In this case, I'm going to have to know what signal is driving the HSI
at all times so I really do have to come up with a good annunciator.
I'm not sure, but I think Paul's installation is simpler than what I'm
doing.
Vern
----- Original Message -----
From: "Jim Stone" <jsto1(at)tampabay.rr.com>
Subject: RE: AeroElectric-List: GPS Annunciator
>
> Vern,
>
> I'm not sure why the built-in functions described in the user manual for
> the 300XL wouldn't be sufficient.
> http://www.garmin.com/manuals/GNC300XLTSO_PilotsGuide.pdf and search
> "annunciator" seems to indicate a lot of capability.
>
> You might want to check out "Annunciator" (AK-950) at Southeast
> Aerospace. I see that Paul Lee is using one in his progect
> (http://www.abri.com/sq2000/19.html). For spec's see
> http://www.ameri-king.com/gps_accessories.html.
>
> Jim Stone
> Jabiru J450.
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: GPS Annunciator |
In a message dated 3/18/2005 11:15:52 A.M. Central Standard Time,
vernw(at)ev1.net writes:
Jim,
An annunciator may not be needed if the 300XL is the only Nav attached
to a Nav head, but in my case, I'm going to be using the 300XL along with
the SL-30 and run them both to the GRT EFIS for Nav and HSI indication.
In this case, I'm going to have to know what signal is driving the HSI
at all times so I really do have to come up with a good annunciator.
I'm not sure, but I think Paul's installation is simpler than what I'm
doing.
Vern
Good Morning Vern,
As I said earlier, I am not familiar with that radio, but when I installed
my IFR Approach Approved Trimble 2000 Approach Plus many years ago, (which
was not mounted in my primary viewing area,) I did it all with small light
bulbs and a couple of double pole, double throw, switches. Your set may require
a resolver. That could complicate the switching, but such wiring is way over
my head.
One factor has to do with automatic switching from GPS to ILS when an ILS
frequency is selected on the "primary" navigation radio.
Such a function may be required by regulatory authorities of some countries,
but it is NOT required for aircraft used in the US National Airspace
System. Many installation shops think it is, but they are WRONG. If you want
that
capability, that is fine, but if you don't want that capability, it is not
required.
Make sure that it is what you want, not just what some installer thinks you
need.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | Jim Oke <wjoke(at)shaw.ca> |
| Subject: | Re: GPS Annunciator |
Speaking in generic terms, the reason a "separate annunciator" function is
required in a certified installation is to place an indicator of certain
modes or cautions being activated in the usual instrument scan of the pilot.
The idea is that even if the GPS box gives a plain enough RAIM or other
warning on its own display, this might go unnoticed by the pilots if the box
is far out of the normal instrument scan. If a RAIM warning light is placed,
say, just beside the ASI, it will likely be noticed by the pilot who will
then check the box and react accordingly.
The various TSOs will specify what functions must be "announced" in this
fashion. Most "certifiable" boxes will provide output circuits that will
drive the appropriate lights or whatever for this.
Jim Oke
Wpg., MB
----- Original Message -----
From: "Jim Stone" <jsto1(at)tampabay.rr.com>
Subject: RE: AeroElectric-List: GPS Annunciator
>
>
> Vern,
>
> I'm not sure why the built-in functions described in the user manual for
> the 300XL wouldn't be sufficient.
> http://www.garmin.com/manuals/GNC300XLTSO_PilotsGuide.pdf and search
> "annunciator" seems to indicate a lot of capability.
>
> You might want to check out "Annunciator" (AK-950) at Southeast
> Aerospace. I see that Paul Lee is using one in his progect
> (http://www.abri.com/sq2000/19.html). For spec's see
> http://www.ameri-king.com/gps_accessories.html.
>
> Jim Stone
> Jabiru J450.
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
>
>Bob will probably chime in with a more thorough explanation but in the
>meantime this may suffice...
>
>Heavy iron traditionally uses a constant speed drive (CSD) transmission
>to keep the alternator speed and frequency constant at 400 Hz. If you
>leave out the CSD and direct drive the alternator, then the frequency
>will vary with engine speed and be "wild". Since a turbine usually idles
>at 50% or more of full power accessory drive rpm, then the frequency
>can double from idle to full power. A three phase AC motor would of
>course also double its speed when the AC frequency is doubled. In some
>cases designing for that, or using DC motors, is presumably
>cheaper/lighter/more reliable than using a CSD.
>Ken
Dead on Ken. The alternators on the B-52 in 1960 had
constant speed drives to maintain 400 Hz from the
alternators over full operating range of engine RPM.
These are basically hydraulic pumps driving hydraulic
motors of the wobble plate variety. A governor attached
to the wobble plates maintains fluid flow from
pump to motor such that output RPM was constant irrespective
of engine RPM.
A few years hence, someone decided that we could eliminate
an expensive heavy drive system if devices requiring AC
power could be made to accept a wider range of frequencies.
Transformers can be designed with 400Hz windings and core
magnetics but fabricated from 1000Hz materials with respect
to losses and guess what? The thing runs fine over range
of 400-1000 Hz.
This is the philosophy of choice for new systems design
and has been in place now for perhaps 20 years or more.
Bob . . .
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Matt Prather wrote:
> Mr Nuckolls' recent whitepaper is an analysis of the electrical performance
> and behavior of a crowbar system. It talks mostly about what the voltage
> and \
> current on the bus are when the Crobar is thrown on the line. The whitepaper
> was in response to recent discussion about these dynamics. It isn't a
> treatise
> on the universal applicability of such a system. I don't think it makes
> an comment about what type of alternator/regulator system it is most
> applicable to.
>
> Your question is about the use of an alternator/regulator system where there
> is some doubt about controlling alternator output via the systems control
> lead.
> In this case, a crowbar, by itself, certainly is not adequate protection
> for other
> devices on the bus.
>
> I hope that helps.
Hi Matt,
Actually, my question was intended to be a lot more specific than that.
I think Paul Messinger raised concerns about a load dump damaging
regulators when the contacter is opened on the "B" lead, because the
crowbar short drives the alternator to full output before the contacter
opens.
In the whitepaper, Bob said
"If one uses a crowbar OV module in combination with an internally
regulated alternator, field supply to the alternator is choked off at
the 2 volt level as soon as the SCR fires . . . the alternator is
already starved for field current long before the breaker opens."
My question is: "Is that really true?" I can see how that would be the
case for an externally regulated alternator, but I am not convinced that
dropping the field voltage to 2 volts would do anything to reduce the
output from an internally regualted alternator - which is the original
problem.
I have no doubt the crowbar would protect the rest of the devices on the
bus, but the concern is what could it do to the regulator if you open
the B lead when the alternator is producing maximum output.
I have some similar concerns about the system I will have on my Rotax,
as the suggested design for that also has a contacter on the output
lead, although (correct me if I'm wrong) I don't think the PM
alternators have the same problem with load dump because they don't
control the magnetic field.
--
Andrew Rowley
arowley(at)ncable.net.au
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
| Subject: | headset level to mic level for recording |
I'm not even sure if it's called a "pad" but I think it is... Here's the
deal. I bought a digital voice recorder thing from Radio Smack with the
intention of recording intercom & radio activity in the plane. The recorder
has an 1/8" mic jack, and it has two "sensitivity" settings, hi and lo. I
connected the passenger headset jack to the mic jack on the recorder, and
not surprisingly the recorder is slightly overloaded level-wise.
I recall seeing an XLR device called a "pad" which allows you to select
impedance or something to that effect.
Is there a simple way to drop/adjust the headset jack output level to be
suitable as "mic level"? I found this via Google:
http://www.hut.fi/Misc/Electronics/circuits/line_to_mic.html
...but I think that applies to line level, not headset level. Maybe
somebody can set me straight and provide some "for dummies" instruction on
this.
Thanks in advance,
)_( Dan
RV-7 N714D
http://www.rvproject.com
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Ah, I see what you are getting at.
Some internally regulated alternators source their field current through
internal pathways and some source it from the control lead. What Mr.
Nuckolls says is true for an internally regulated alternator which gets
its field current through the control lead.
For the other style, when the SCR fires, it holds the bus voltage down to
around 11V until the breaker opens, at which point the B-lead contactor
opens. As the article says, the contactor may stay closed until breaker
opens - dropping only to 2 or so volts. But, the opening time of the
contactor is much faster then when at 13volts. At this point, the only
thing that might be dangerous is that the internal regulator or field winding
overheats itself with 100% field current. Probably a very small risk of
fire
there. My 'guess' is that alternators are designed to reach their rated
output at 100% field current. Anybody care to comment on that? If so, the
alternator shouldn't overheat.
Regards,
Matt-
>
>
> Matt Prather wrote:
>
>> Mr Nuckolls' recent whitepaper is an analysis of the electrical
>> performance and behavior of a crowbar system. It talks mostly about
>> what the voltage and \
>> current on the bus are when the Crobar is thrown on the line. The
>> whitepaper was in response to recent discussion about these dynamics.
>> It isn't a treatise
>> on the universal applicability of such a system. I don't think it
>> makes an comment about what type of alternator/regulator system it is
>> most applicable to.
>>
>> Your question is about the use of an alternator/regulator system where
>> there is some doubt about controlling alternator output via the
>> systems control lead.
>> In this case, a crowbar, by itself, certainly is not adequate
>> protection for other
>> devices on the bus.
>>
>> I hope that helps.
>
> Hi Matt,
>
> Actually, my question was intended to be a lot more specific than that.
> I think Paul Messinger raised concerns about a load dump damaging
> regulators when the contacter is opened on the "B" lead, because the
> crowbar short drives the alternator to full output before the contacter
> opens.
>
> In the whitepaper, Bob said
> "If one uses a crowbar OV module in combination with an internally
> regulated alternator, field supply to the alternator is choked off at
> the 2 volt level as soon as the SCR fires . . . the alternator is
> already starved for field current long before the breaker opens."
>
> My question is: "Is that really true?" I can see how that would be the
> case for an externally regulated alternator, but I am not convinced that
> dropping the field voltage to 2 volts would do anything to reduce the
> output from an internally regualted alternator - which is the original
> problem.
>
> I have no doubt the crowbar would protect the rest of the devices on the
> bus, but the concern is what could it do to the regulator if you open
> the B lead when the alternator is producing maximum output.
>
> I have some similar concerns about the system I will have on my Rotax,
> as the suggested design for that also has a contacter on the output
> lead, although (correct me if I'm wrong) I don't think the PM
> alternators have the same problem with load dump because they don't
> control the magnetic field.
>
> --
> Andrew Rowley
> arowley(at)ncable.net.au
>
>
________________________________________________________________________________
| From: | rv-9a-online <rv-9a-online(at)telus.net> |
| Subject: | Re: headset level to mic level for recording |
Dan, the link you provided shows the correct way to attenuate the
signal. The resistor values may need to be adjusted, but the app note
is a good starting point. If you don't want to hardwire it into your
airplane, you can build it externally and wrap it in heat shrink. You'd
need to make a cable with a jack and a plug as well, so that you can
insert your gizmo in series with your recorder.
You could also use a volume control potentiometer in place of the two
resistors, (10K pot would work) and have total control on the levels.
The volume control will have three leads: connect one outside lead to
your headphone plug (tip), the other outside lead to headphone plug
ground (sleeve). Then connect the middle lead and ground to the
miniature audio jack.
I hope this helps.
Vern Little, RV-9A.
And thanks for the great website!
Dan Checkoway wrote:
>
>I'm not even sure if it's called a "pad" but I think it is... Here's the
>deal. I bought a digital voice recorder thing from Radio Smack with the
>intention of recording intercom & radio activity in the plane. The recorder
>has an 1/8" mic jack, and it has two "sensitivity" settings, hi and lo. I
>connected the passenger headset jack to the mic jack on the recorder, and
>not surprisingly the recorder is slightly overloaded level-wise.
>
>I recall seeing an XLR device called a "pad" which allows you to select
>impedance or something to that effect.
>
>Is there a simple way to drop/adjust the headset jack output level to be
>suitable as "mic level"? I found this via Google:
>
>http://www.hut.fi/Misc/Electronics/circuits/line_to_mic.html
>
>...but I think that applies to line level, not headset level. Maybe
>somebody can set me straight and provide some "for dummies" instruction on
>this.
>
>Thanks in advance,
>)_( Dan
>RV-7 N714D
>http://www.rvproject.com
>
>
>
>
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: White Paper on Crowbar OV Protection |
Matt Prather wrote:
>
> Ah, I see what you are getting at.
>
> Some internally regulated alternators source their field current through
> internal pathways and some source it from the control lead. What Mr.
> Nuckolls says is true for an internally regulated alternator which gets
> its field current through the control lead.
>
> For the other style, when the SCR fires, it holds the bus voltage down to
> around 11V until the breaker opens, at which point the B-lead contactor
> opens. As the article says, the contactor may stay closed until breaker
> opens - dropping only to 2 or so volts. But, the opening time of the
> contactor is much faster then when at 13volts. At this point, the only
> thing that might be dangerous is that the internal regulator or field
winding
> overheats itself with 100% field current. Probably a very small risk of
> fire
> there. My 'guess' is that alternators are designed to reach their rated
> output at 100% field current. Anybody care to comment on that? If
so, the
> alternator shouldn't overheat.
I wouldn't be worried about the alternator overheating. The problem that
has been described is Vans alternators failing on systems where the OVP
is installed. The question then is how might the OVP do something that
damages the alternator (actually most likely the regulator I think).
Would I be right in assuming that if the alternator sources field
current through the control lead, the traditional method of turning off
the control lead would shut off the alternator, and cutting the B lead
is not necessary? So when we discuss opening the B lead contactor, we
are talking about systems that do not source field current through the
control lead?
If I understand correctly, Paul is saying that opening the B lead
produces a load dump event which is effectively internal to the
alternator, and doesn't even have a battery connected any more to absorb
it. This then may damage components in the alternator due to overvoltage.
However, as I said in a different message, if you can't turn the
alternator off by the control lead, and you want to be able to shut off
the alternator, I don't see much alternative other than disconnecting
the "B" lead.
--
Andrew Rowley
arowley(at)ncable.net.au
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Points for discussion OVP//more |
Its not the same and more like what Bob recommends.
I have gotten back and will be responding to all the commenst in one way or
the other soon.
Paul
There is more to life than this list :-)
----- Original Message -----
From: "John Swartout" <jgswartout(at)earthlink.net>
Subject: RE: AeroElectric-List: Points for discussion OVP//more
>
>
> Paul, thanks for being patient with me and others on this list who are
> neophytes. Trying to follow along, learn something, and build a better
> airplane.
>
> Is the system you describe below approximately the same thing as the
> Zeftronics-built ASP101 Overvoltage protection sold by Niagara Airparts
> (described and schematicized here:
> http://www.niagaraairparts.com/ASP101-PIT%201.pdf), except that you add
> the transorbs?
>
> Thanks.
>
> John
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Paul
> Messinger
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Points for discussion OVP//more
>
>
>
>
> Use the proper size fuse in the "B" lead. I suggest that a 55 amp
> alternator
> should use a 60 amp as that fuse is designed to run forever at 60 amps
> and
> hopefully your load will hardly ever approach 55 amps. A failed and
> shorted
> alternator will supply more than rated current but lets not over due it.
>
> Use a OVP that opens the alternator field circuit. The 16.2V setting is
> fine. Eric Jones has this as a stock item. Please do not use a shorting
> crowbar here as that is cruel and unusual punishment to the electrons.
>
> Put a parallel set of 16V transorbs across the system bus between the
> fuse
> and the bus. The transorbs will clamp the bus to under 20V and blow the
> fuse
> if the failure is a real (quite rare)failure of the alternator that the
> field lead cannot control. Normally the field OVP will trip (having a
> 200 ms
> delay for load dump transients) and correct the problem. If this fails
> the
> transorbs will clamp the bus to a safe level and blow the fuse. The
> number
> of transorbs is under investigation (6-10 max expected worst case) but
> they
> are low cost ($0.41 each) in small quantities and Mouser has them in
> stock
> at this time.
>
> Look for 1N6276A or 1.5KE16A they are the same part functionally.
>
> The KISS principal wins another battle.
>
> Paul
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Points for discussion OVP//more |
Embedded comments after snipping for brevity.
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Points for discussion OVP//more
>
>
>
>>
>>Use a hi quality ND rebuild alternator and / or a new one. One with a hi
>>quality regulator that controls the field all the time.
>
> I've wrestled with this issue for years. The term "high quality"
> is simply not quantifiable.
It is around here if you know what auto parts dealer to go to.
I go in and ask for a part and the reply is what quality level do you want?
The usual brand of parts makes 2 or 3 quality levels normal good and high.
This independent auto store with mechanics for salesmen are great. The store
will order the normal quality level if you insist but do not stock this
level as there have been too many returns.
The good quality is what is stocked and one needs to special order the High
quality.
Take the GM HEI control module I use in hundreds of dual ign systems for
Subaru engines. Only the Hi quality is flight proven to last. lower quality
levels fail.
Or take the external "ford" alternator regulator. Only the High quality unit
has OVP built in and flashes the "idiot light in case of alternator failure.
Typical pricing might be 20 for normal, 40 for good and 75 for High quality
levels.
Many do not know this variability of parts quality exist either because they
deal with a major chain or the sales staff do not know about it.
I have de-lidded etc the different quality levels and there is a significant
difference in design and parts quality. You get what you pay for.
>
>>Use the proper size fuse in the "B" lead. I suggest that a 55 amp
>>alternator
>>should use a 60 amp as that fuse is designed to run forever at 60 amps and
>>hopefully your load will hardly ever approach 55 amps. A failed and
>>shorted
>>alternator will supply more than rated current but lets not over due it.
>
> How so? For several years we used to supply JJN- and JJS series
> fuses for alternator b-lead protection. A 60-amp fuse was offered
> for both 40 and 60 amp alternators. Several years into the activity,
> folks started complaining about popping the 60A fuse on an L-60
> installation.
>
> After some invstigation we found that the fuses popped when
> the owner tried to charge a dead battery by running the engine.
> The cold L-60 would easily open a 60A fast fuse.
This was a lets see what Bob would say. Do you have any real data that
states the maximum output of any 55 amp alternator when supplied with 14V DC
to the field and is turning at 8,000 rpms?
I do not but you have often said the max out put is only slightly higher
than rated.
I now have a 500 amp load tester and will be testing the more or less ND
alternator in the next few weeks. We will see what it can produce. However
every brand and style may have different max currents. My testing to date
suggests that the max output will be much greater under a full dc
application of field voltage.
>
>>Use a OVP that opens the alternator field circuit. The 16.2V setting is
>>fine. Eric Jones has this as a stock item. Please do not use a shorting
>>crowbar here as that is cruel and unusual punishment to the electrons.
>
> "Cruel and unusual" is not quantified.
lighten up its supposed to be funny!
Went to the bench this afternoon
> and duplicated some work I did at Electro-Mech about 25 years ago.
> See white paper report at:
>
> http://www.aeroelectric.com/articles/Crobar_OV_Protection/Crowbar_White_Paper.pdf
I have extensive comments on this in a soon to be posted review!
>
> If you set the voltage regulator for 16.3 volts with the transorbs
> in place, will they take the system off line?
No and what is magic about any voltage above 15.5 and below 16.5??? It seems
to me that 16V was picked as high enough to be easy to reliability set with
the parts available years ago. Today there is no reason for a wide voltage
margin of safety. Of course the OVP must not have a hair trigger and false
trip from load dumps or contactor contact bounce induced spikes (yes I have
captured on film the elusive "snipe" Perhaps private joke between us Bob :-)
I would set a OVP at 15.50-15.75V trip only after 200ms. The OVP would only
OPEN the "B" lead and do it using a fet not a huge contactor etc. The
transorbs are there for load dumps, transients, and if one wanted to
continue flight with a battery system failure etc. More on this soon.
Paul
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator Control |
As I have stated there are different "qualities" of ND alternator rebuilds
and older ones have on occasion been the type where field control was lost
once they were turned on.
Vans regulators are different from yours as field control is always
externally controlled unless there is an internal failure of the regulator.
Modern regulators are much less likely to have hard failures internally with
the advent of modern autos and the extensive electronics installed.
A brand new alternator for an older auto may have the older style of
regulator as the auto wiring may expect the old once on always on type of
control. Thus there is a danger of any new or rebuilt alternator sold for an
older auto containing the modern internal regulator. I am unwilling to
guess.
Can you share with us what happened and what was the source of your failed
alternator?
Paul
----- Original Message -----
From: "Richard Garforth" <richard(at)hawk.flyer.co.uk>
Subject: AeroElectric-List: Alternator Control
>
>
> Paul,
>
> Having just had a real long and bad experience with ND internally
> regulated alternators (without OV protection). I am curious about your
> statement that suggests you can turn off the alternator via the 'field
> control' lead. My experience has been you can initiate o/p by applying
> +12v to the 'field' lead but subsequent removal of the 12 volts leaves the
> alt churning out amps. Have the alternators supplied by VANS (60 amp ND) a
> different regulator ?
>
> Richard ( a convert to B&C )
>
________________________________________________________________________________
| Subject: | Re: White Paper on Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Huh.. I think we are going in circles here.. I went back to the archive and
re-read one of your earlier posts.
"If a device that simply opens the B lead is enough to damage the
alternator, it doesn't sound like the real reason is the OVP module
(although it is possible it could make a problem more likely). It
suggests to me that these alternators should not be disconnected at all
once running, and if you want the ability to do that maybe they are not
suitable. Of the thousands of aircraft flying without failures, how many
have tested what happens if the alternator is disconnected?"
I agree. The alternators that Van's sells probably are ones which
don't source the field current through the sense wire. They are probably
automotive derivative and as such, running without a battery wasn't one of
the design parameters.
Operationally, the risk of damage from a disconnect can probably be
minimized. Take actions which disconnect the b-lead only when the
loads and possible output are low. Don't cycle the alternator on a cold
night when all the lights are on and the engine is turning cruise RPM.
Whether an alternator which supplies its field current through the control
wire should be installed with a b-lead contactor is debatable. If I use an
alternator that has internal regulator, it will have the contactor. I
don't know
what the fail modes in the regulator are.. Is there another path for
excitation
to get through?
Regards,
Matt-
VE N34RD, C150 N714BK
>
>
> Matt Prather wrote:
>
>
> >
> > Ah, I see what you are getting at.
> >
> > Some internally regulated alternators source their field current
> through internal pathways and some source it from the control lead.
> What Mr. Nuckolls says is true for an internally regulated alternator
> which gets its field current through the control lead.
> >
> > For the other style, when the SCR fires, it holds the bus voltage
> down to around 11V until the breaker opens, at which point the B-lead
> contactor opens. As the article says, the contactor may stay closed
> until breaker opens - dropping only to 2 or so volts. But, the
> opening time of the contactor is much faster then when at 13volts.
> At this point, the only thing that might be dangerous is that the
> internal regulator or field
> winding
> > overheats itself with 100% field current. Probably a very small
> risk of fire
> > there. My 'guess' is that alternators are designed to reach their
> rated output at 100% field current. Anybody care to comment on that?
> If
> so, the
> > alternator shouldn't overheat.
>
> I wouldn't be worried about the alternator overheating. The problem that
> has been described is Vans alternators failing on systems where the OVP
> is installed. The question then is how might the OVP do something that
> damages the alternator (actually most likely the regulator I think).
>
> Would I be right in assuming that if the alternator sources field
> current through the control lead, the traditional method of turning off
> the control lead would shut off the alternator, and cutting the B lead
> is not necessary? So when we discuss opening the B lead contactor, we
> are talking about systems that do not source field current through the
> control lead?
>
> If I understand correctly, Paul is saying that opening the B lead
> produces a load dump event which is effectively internal to the
> alternator, and doesn't even have a battery connected any more to absorb
> it. This then may damage components in the alternator due to
> overvoltage.
>
> However, as I said in a different message, if you can't turn the
> alternator off by the control lead, and you want to be able to shut off
> the alternator, I don't see much alternative other than disconnecting
> the "B" lead.
>
> --
> Andrew Rowley
> arowley(at)ncable.net.au
>
>
________________________________________________________________________________
| From: | Jerzy Krasinski <krasinski(at)provalue.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
>
> A few years hence, someone decided that we could eliminate
> an expensive heavy drive system if devices requiring AC
> power could be made to accept a wider range of frequencies.
> Transformers can be designed with 400Hz windings and core
> magnetics but fabricated from 1000Hz materials with respect
> to losses and guess what? The thing runs fine over range
> of 400-1000 Hz.
>
> This is the philosophy of choice for new systems design
> and has been in place now for perhaps 20 years or more.
>
> Bob . . .
>
>
>
Bob,
Just for curiosity, what frequency is generated by alternator (before
rectification) in a typical Cessna in cruise conditions?
Jerzy
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: White Paper on Crowbar OV Protection |
If the internal regulator gets all its power from the field lead then
opening this lead stops the alternator output current. I have modified
several brands to eliminate the internal "B" lead to regulator connection
and then the only "B" lead protection is a fuse. Not easy to do on ND brand.
GOOD alternator internal regulators have adequate load dump protection built
in. Why Vans fail when coupled with OVP and not just Bobs is a mystery at
present. Vans has no answer.
However its not necessary to disconnect the "B" lead when the alternator is
running except in a failure mode. It should never be done as a matter of
testing in my opinion.
Paul
----- Original Message -----
From: "Matt Prather" <mprather(at)spro.net>
Subject: Re: AeroElectric-List: White Paper on Crowbar OV Protection
>
>
> Huh.. I think we are going in circles here.. I went back to the archive
> and
> re-read one of your earlier posts.
>
> "If a device that simply opens the B lead is enough to damage the
> alternator, it doesn't sound like the real reason is the OVP module
> (although it is possible it could make a problem more likely). It
> suggests to me that these alternators should not be disconnected at all
> once running, and if you want the ability to do that maybe they are not
> suitable. Of the thousands of aircraft flying without failures, how many
> have tested what happens if the alternator is disconnected?"
>
> I agree. The alternators that Van's sells probably are ones which
> don't source the field current through the sense wire. They are probably
> automotive derivative and as such, running without a battery wasn't one of
> the design parameters.
>
> Operationally, the risk of damage from a disconnect can probably be
> minimized. Take actions which disconnect the b-lead only when the
> loads and possible output are low. Don't cycle the alternator on a cold
> night when all the lights are on and the engine is turning cruise RPM.
>
> Whether an alternator which supplies its field current through the control
> wire should be installed with a b-lead contactor is debatable. If I use
> an
> alternator that has internal regulator, it will have the contactor. I
> don't know
> what the fail modes in the regulator are.. Is there another path for
> excitation
> to get through?
>
> Regards,
>
> Matt-
> VE N34RD, C150 N714BK
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: OV protection debate |
I did testing that included all you seem to want in the Load Dump study.
I setup a simple but complete electrical system (using real sized wiring and
gauges) from battery to running alternator. For the OVP testing I tested 3
different CB styles from 2 mfgrs to verify the data.
I have several hundred photos and many pages of test results that are on the
slow path to being on my web site.
However there is a fundamental difference of opinion in how to control load
dump and more important how to stop a runaway alternator in the modern
aircraft with modern avionics.
Eric Jones and I have designed and tested a method of OVP protection that
eliminates any large current surges and spikes before and after the Crowbar
approach. The crow bar approach takes a few milliseconds to start clamping
and after its opens the cb there may remain a large spike that comes from
the alternator before the "B" lead contactor finally opens.
I have taken a lot of heat from Eric on publishing the complete report but I
have so little time and so much to do. Eventually is what #2 priority gets
:-) If one only publishes parts there are unanswered questions that remain.
Also I dislike to report in pure engineering terms as there are so few that
would understand what I am saying and so many that need to hear it in
general english.
Paul
----- Original Message -----
From: "Tim Olson" <Tim(at)MyRV10.com>
Subject: Re: AeroElectric-List: OV protection debate
>
> Would it maybe not help solve some of this debate as to the OV
> protection if perhaps Eric, Paul, and Bob all drew up their
> favorite OV protection circuit, and maybe one or all of them
> took the time to actually run them and produce a situation
> that would cause trouble? I know Bob ran his circuit to
> prove his....but I'd be interested to see a couple of different
> OV options, and graphs of voltage and current spikes that
> happened when an OV condition was created. It seems like
> all of this debating back and forth could be settled
> with just a few hours of directly compared experiments...
>
> Tim
________________________________________________________________________________
| From: | "Ron Brown" <romott(at)adelphia.net> |
| Subject: | headset level to mic level for recording |
>I'm not even sure if it's called a "pad" but I think it is... Here's the
>deal. I bought a digital voice recorder thing from Radio Smack with the
>intention of recording intercom & radio activity in the plane. The recorder
>has an 1/8" mic jack, and it has two "sensitivity" settings, hi and lo. I
>connected the passenger headset jack to the mic jack on the recorder, and
>not surprisingly the recorder is slightly overloaded level-wise.
I have the same set up and use an in-line volume control like this one also at
the shack. Works great!!!
http://www.radioshack.com/product.asp?catalog%5FnameCTLG&product%5Fid42-2559
________________________________________________________________________________
| From: | "Mike Lehman" <lehmans(at)sympatico.ca> |
| Subject: | Re: Crowbar OV Protection |
My question refers to the VR-166 Ford type voltage regulator with an
alternator B+ to regulator terminal 'A' connection supplying alternator
field current. When the crowbar protection reduces VR terminal 'S' to under
2 volts, is the field current supply via terminal 'A' always interrupted? I
presume that the answer depends on the failure mode of the VR-166 that
caused the crowbar to 'fire' in the first place.
In other words, with the old mechanical VR-166, I have confidence that the
crowbar protection is adequate. Substituting an electronic VR-166 (with the
B+ to terminal 'A' wire, not with terminal 'A' and 'S' jumpered per Bob's
diagrams) seems to create the equivalent of an alternator with an internal
voltage regulator.
Hopefully, alternator field current via VR termimal 'A', with terminal 'S'
de-energized, is a low probability VR-166 failure mode? Anyone really know
???
Mike
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
"Nice attempt at humor but you "digress" to much."
Methinks thou dost complain two much.
Ferg
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Points for discussion OVP//more |
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Points for discussion OVP//more
>
>
>
>>
. . . but assuming your system
> IS capable of producing a 250A trip current, is there
> any analysis to support the notion that this is "bad"
> for other systems in the aircraft?
>
> Bob . . .
Seems to me you have it backwards (you need to prove its compatible with
today's electronics). With today's avionics that may contain sensitive
magnetometers as well as truly electric dependent engines where dropping
below 11V at the battery can cause the engine computer to reset. Remember
all the discussion regarding electronic mags and the need for a special
battery during starting to keep the voltage high with the high starting
current typical with Lyc's etc??
Then there is the increasing use of Hall effect devices for current sensing.
One manufacturer of such devices states that a 100% over current will cause
a calibration shift. So much for accurate current measurements. The list of
potential concerns seems endless to me.
Given that I am working on a 21st century aircraft engine that is derived
from an auto engine; I have measured the starting current, including peak
currents. The current path does not go close to the instrument panel as the
crowbar CB that is mounted there does. A modern geared starter need not have
high currents like the stock Lyc starters do. Also with a smaller
displacement engine that is geared down, the power to turn it over is much
smaller. My need for measuring worst case starting current is an important
design requirement when designing solid state contactors. (The design is for
300 amps max starting while cranking and an inrush peak of more than 500
amps).
The peak starting current (with the engine I am working with) is under 200
amps (at least as measured with a 500 amp current shunt and a 400 MHz scope
system). After a peak of under 200 amps the starting current varies from 110
to 130 amps depending on compression stroke vs. power stroke in the engine.
The battery terminal voltage never drops under 11V (but the batteries are
not as you suggest but batteries designed for starting etc. ( See a 'to be
posted' discussion)
The use of old technology (Crowbars) with modern equipment can be a problem
and considering that the only supporter of a crowbar (anywhere in general
aviation aircraft?) seems to be from you so that puts the burden of proof
(that its still a good idea and safe to use) on you. A developer of a new
avionics system who only looks at certificated aircraft will not notice your
design, nor will those who also inquire with major experimental aircraft
manufacturers like Vans. I agree that protection is needed but the old
approach of using a crowbar in this way never was the best way and today is
no longer a potentially safe approach.
A realistic wiring setup (as used in a real aircraft) with a really good
battery plus a nominal CB (see CB data sheet) can produce far higher trip
currents and much longer trip times that your sample of one test shows).
More than enough to cause a reset of the engine computer depending on the
variables an individual aircraft might have. Even 250 amps is several times
the MIG or TIG welding current needed for a steel tube structure in an
aircraft. Surely you would not suggest that the avionics be installed when
doing welding in the cockpit area, but in effect, that is what the crowbar
does.
What bothers me is your the comments about how simple and low parts count it
has and has been working for 30 years. Neither has anything to do with our
concerns that my testing (and investigations) have demonstrated to me are
valid.
Also adding just one part to your crowbar could reduce the current surge to
a reasonable level and still provide the function of opening the CB. Add
another part or two and you can open the "B" lead contactor power (and open
the contactor) without resorting to the high current presently used to pop
the CB. So 3-4 parts added and no need to pop the CB and no hi current
surge. In my opinion this should have been part of the original design.
The approach Eric sells has been extensivitely tested by both of us and not
only has no current surge but has 100% of the time protection against OV
conditions (which your approach does not do; see another upcoming post on
this). Also it eliminates the heavy "B" lead contactor (In one of Eric's
approaches ).
The only down side I see to any of the above is its a change from your
traditional approach.
It may be of interest that Denso has a belt connected (not gear connected)
starter and alternator "all in one" for the modern auto where the engine is
stopped every time the auto is stopped. The web pictured device appears to
be a simple alternator but actually contains a starter also. Designed 4
years ago!
Paul
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: "Vern W."
<>
AeroElectric-List message previously posted by: "Vern W."
<>
3/19/2005
Hello Vern, You are struggling with a problem that many of us have
confronted so it is worth exploring more in depth. Some comments to assist
in this exploration:
1) This is not simply an annunciator problem. When you feed the GRT EFIS (or
any CDI) from either the 300XL or the SL-30 you need an interface device
(many relays) to transfer all of the appropriate information signal inputs
from the sending devices to the receiving device (navigation indicator).
2) And you need a switch or button of some kind to activate that interface
device to tell it which source to use to drive the navigation indicator
(receiving device).
3) So the fundamental questions are: What are you using as an interface
device (a box with many relays inside) and how are you controlling that
interface device?
4) Once the interface device is chosen then you have at least three ways to
tell which source is feeding the navigation indicator:
4A) A simple two position switch - one position is labeled SL-30 and the
other is labeled 300XL. Depending upon which position the switch is in then
the interface box relays are connected to feed that source to the navigation
indicator.
4B) A push button, split illuminated switch with one half labeled SL-30 and
one half labeled 300XL that cycles the interface box between the two
sources. Which ever light is lit tells you which source is feeding the
interface box.
4C) A plain push botton switch that cycles the interface box between the two
sources and two lights on the panel, one labled SL-30 the other labled
300XL, that are fed from relays within the interface box. The appropriate
light is lit depending upon which relays are in contact.
5) Some sources for interface boxes with many relays are Perihelion Design
(thanks Eric) and Northern Airborne Technologies.
6) This subject of feeding one navigation indicator from two sources has
been discussed previously on the list if you want to go back into the
archives.
Please come back with some additional questions and thoughts on how you want
to do this.
OC
PS: The term "satisfy IFR requirements" raises the questions: Whose IFR
requirements are you referring to and where are they documented? Let's not
get wrapped around the axle of FAA / FAR requirements for installations in
standard type certificated airplanes.
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: headset level to mic level for recording |
The simplest, non-cut and solder approach is to buy 3 parts from Radio
Shack:
1) Radio Shack Y adapter: Male 1/4" plug end goes into your aircraft's
larger headset jack. Y adapter has 2 1/4" holes/jacks in top, one for your
headset's 1//4" jack and the other for
2) your new Radio Shack 1/8 to 1/4" adapter - plug big end into 2nd hole
of Y adapter;
3) Radio Shack 42-2152, 6.5' Attenuating Dubbing Cord, $3.99, which has
tiny 1/8" male/jack on each end - plug one into your video recorder's "audio
in" (or your digital recorder) and the other into the1/8 to 1/4 adapter [ 2)
above ]
It cuts the amplitude of the aircraft audo system so my video recorder audio
isn't over-driven. It works for me in the Cessna I fly wih a video
recorder.
David Carter
----- Original Message -----
From: "Ron Brown" <romott(at)adelphia.net>
Subject: RE: AeroElectric-List: headset level to mic level for recording
>
>
> >I'm not even sure if it's called a "pad" but I think it is... Here's the
> >deal. I bought a digital voice recorder thing from Radio Smack with the
> >intention of recording intercom & radio activity in the plane. The
recorder
> >has an 1/8" mic jack, and it has two "sensitivity" settings, hi and lo.
I
> >connected the passenger headset jack to the mic jack on the recorder, and
> >not surprisingly the recorder is slightly overloaded level-wise.
>
>
> I have the same set up and use an in-line volume control like this one
also at the shack. Works great!!!
>
>
http://www.radioshack.com/product.asp?catalog%5FnameCTLG&product%5Fid42-2559
>
________________________________________________________________________________
| From: | "Dan O'Brien" <limadelta(at)gmail.com> |
>Paul wrote:
>A developer of a new avionics system who only looks at certificated
> aircraft will not notice your design, nor will those who also inquire
>with major experimental aircraft manufacturers like Vans.
Hmm... the top composite experimental (Lancair) says in its IVP
manual, its ES manual, and its recently updated Legacy manual (see
http://www.lancair-kits.com/manual_revisions/Legacy_manual_rev-0105.pdf,
p. 27-4):
"Robert Nuckolls is also an excellent reference for wiring. He
publishes a newsletter,
The AeroElectric Connection, and also contracts his services to
individual builders to design custom electrical schematics. He can be
reached at:
Medicine River Press
6936 Bainbridge Road
Wichita, Kansas 67226-1008
(316) 685-8617"
While specifics of this may be slightly off or dated (is there a
"newsletter" we don't know about beyond the website?), this is
clearly an endorsement from a pretty big player in the experimental
category. Yeah, Lancair is "small" compared to Vans, but I think it's
number one among the more "modern" composite players. FWIW.
________________________________________________________________________________
| From: | "Dan O'Brien" <limadelta(at)gmail.com> |
| Subject: | Re: Points for discussion OVP//more |
>Paul wrote:
>A developer of a new avionics system who only looks at certificated
> aircraft will not notice your design, nor will those who also inquire
>with major experimental aircraft manufacturers like Vans.
Hmm... the top composite experimental (Lancair) says in its IVP
manual, its ES manual, and its recently updated Legacy manual (see
http://www.lancair-kits.com/manual_revisions/Legacy_manual_rev-0105.pdf,
p. 27-4):
"Robert Nuckolls is also an excellent reference for wiring. He
publishes a newsletter,
The AeroElectric Connection, and also contracts his services to
individual builders to design custom electrical schematics. He can be
reached at:
Medicine River Press
6936 Bainbridge Road
Wichita, Kansas 67226-1008
(316) 685-8617"
While specifics of this may be slightly off or dated (is there a
"newsletter" we don't know about beyond the website?), this is
clearly an endorsement from a pretty big player in the experimental
category. Yeah, Lancair is "small" compared to Vans, but I think it's
number one among the more "modern" composite players. FWIW.
________________________________________________________________________________
| From: | CardinalNSB(at)aol.com |
| Subject: | Re: gps annunciator 300xl |
Vern:
Before I started a new business and had a head-on accident last year I was
thinking I was going to make my own annunciator panel for my Garmin 300xl.
Still thinking...
Good used 300xl can be had at very reasonable prices, I wasn't about to pay
half again just for some lights. I had a good deal of discussions on other
boards, here is what I think I know about installing it in my Cesnna Cardinal,
a certified aircraft. I emphasize that this is based only on my reading and
discussions, that I haven't found any "professionals" that agree with me on
my interpretation of the law as being a minor alteration.
I appreciate any corrections or affirmations or filling in any gaps:
1. IFR installation of gps is a "minor" mod, only log book entry required
unless it is interfaced with something "unusual", based on the AC 20-138, page
11. However, the annunciators and cdi are required in order to be in
compliance with Garmin's initial STC.
2. The cost of the "store bought" annunciator panels exceeds a good used
King ki202 or collins, I decided to directly drive the cdi and not use a relay.
I understand some ARC units will work. You need a resolver in the cdi.
3. The Garmin installation manual shows the needed 6 annunciator lights and
2 switches.
Lights 1, 2, 3, and 4 are driven by the output from the gps, through the
bulb, then to ground.
The gps controls whether the light 1, 2, 3 or 4 is energized.
Message and Arrival lights are independent of all other annunciators.
Approach Resolution Hi or Low is alternatively selected by a momentary
switch to ground a pin, but the switch is not tied to the lights.
Lights 5 and 6
Now here is what I find to be odd. The .gps is in "sequence" mode unless
the sequence pin is grounded. Not a momentary "flip flop" like the Approach
Resolution Mode, rather if its grounded its in Hold Mode and if its not
grounded its in Sequence Mode. BUT there is no driver from the gps for the lights
in either mode. Instead, the installation drawing shows a dpdt switch-in the
up position, the first pole connects power (from the bus, not the gps) to the
Sequence light then to ground and the second pole is unconnected. In the
down position, power flows to the Hold light through the first pole then to
ground and the second pole simply grounds the sequence hold pin, putting the gps
in the Hold mode.
Seems odd to me that they didn't simply output 6 annunciator lights directly
from the gps and control the 2 mode styles with appropriate switching.
4. If you use a relay to switch the cdi between gps/nav, you need another
light to indicate the source driving the cdi. I haven't researched much but
NAT advertises a relay for this. I see this on ebay often.
5. I didn't see anywhere where it listed the output voltage from the gps
for the annunciators, or that the annunciator output level varied with the
unit's own dimming function, so I assume the output is a constant 12v when
activated.
HELP PLEASE. Assuming I got the basic annunciator scheme right, how can I
easily make a multiple LED dimmer? So far, I have the face plate off of an
old annunciator which I intend to put leds behind so I can use the same white
led for each function, so the output of each annunciator will be the same with
no need to vary the voltage between the bulbs (I sure do love those blue
leds though). The problem I see is that out of the 6 lights, 2 will always be
on, sometimes 3, sometimes 4, so if I simply put a rheostat before the (common
bulb leg)ground and it is dimmed for 2 lights, and then 4 become activated,
there might not be enough voltage to light the leds. Bad if a RAIM message
is missed.
Would a circuit based on a LM 3914 be appropriate (between the gps and the
led), or can someone point me to a source for dimming multiple leds from a
common knob. Its a good thing this is a hobby... thank you Skip Simpson
but a
Light 1 is Message, driven by the Garmin 300xl, grounding the light .
Light 2 is activated by an internal relay to ground.
Light 3 is activated by an internal relay to ground.
Light 4 is activated by an internal relay to ground.
Light 5 and 6 are controlled by a dpdt switch.
Voltage goes into the dpst switch. In the up position, Light
In position up, light is on
. 4 lights are activated by
.
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Tap into antenna coax? |
I recently ripped out all the 25-30 year-old avionics in my plane and
installed a modern all-in-one box. Now I would like to semi-permanently
install a T-type tap at the antenna end of the coax for my primary comm.
The idea would be to have a second coax run going to the handheld I keep
for emergency backup.
Although it is fine in the local area, the heavily loaded short whip
antenna the handheld comes with doesn't work very well in cruise at
altitude, especially here in the SW where there are long stretches of
really empty country. Hooked to a regular comm antenna, though, it is
sufficient.
My planned use would be to have *either* the primary comm *or* the
backup radio turned on at any time, never both. Is this idea OK???
Will it work???
Andy Elliott
N481HY/AA-1(TD,160)/KFFZ
That's "One Hot Yankee"
http://members.cox.net/n481hy/
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Points for discussion OVP//more |
Thanks for your comment.
For the record I repeat what I have said in the past.
"Bob has contributed more than ALL the others combined for the homebuilders
electrical wiring systems"
That does not mean everything suggested should be used blindly nor is
everything the best in today's world.
I doubt that many realize the huge currents (and I have documented 400 amps
+ many times) that can be produced by the OVP and frankly likely with the LR
series of external regulators. I can find nothing suggestion the possibility
of such currents and the potential for side affects. As a extremely simple
mod reduces the peak current to reasonable values and does nothing to the
functionally of the OVP I simply find Bob's resistance strange to say the
least. 25 amps will pop the fuse nearly as fast without the potential side
affects.
You know I never gave Bob's OVP approach much thought until the load dump
testing we did last year. I never was a proponent of crowbars and NEVER
where the crowbar was used to short a hi current battery ALL my engineering
peers were astounded to find there was a non current limited crow bar being
used across a battery as none had ever seen or heard of such an application.
I would be surprises if anyone at Lance realized the specific currents
produced by the OVP in their blanket endorsement of Bob. BTW I have often
sent builders to Bob for design and building methods for their electrical
system with the exception of those with an electrically dependent aircraft
where Bob has not completely addressed the issues unique to an engine that
needs 10-20 amps just to run and cannot stand even momentary battery
terminal voltage under approx 11.0 V.
More on this in other past and future posts.
Paul
----- Original Message -----
From: "Dan O'Brien" <limadelta(at)gmail.com>
Subject: AeroElectric-List: Re: Points for discussion OVP//more
>
>
>>Paul wrote:
>>A developer of a new avionics system who only looks at certificated
>> aircraft will not notice your design, nor will those who also inquire
>>with major experimental aircraft manufacturers like Vans.
>
> Hmm... the top composite experimental (Lancair) says in its IVP
> manual, its ES manual, and its recently updated Legacy manual (see
> http://www.lancair-kits.com/manual_revisions/Legacy_manual_rev-0105.pdf,
> p. 27-4):
>
> "Robert Nuckolls is also an excellent reference for wiring. He
> publishes a newsletter,
> The AeroElectric Connection, and also contracts his services to
> individual builders to design custom electrical schematics. He can be
> reached at:
>
> Medicine River Press
> 6936 Bainbridge Road
> Wichita, Kansas 67226-1008
> (316) 685-8617"
>
> While specifics of this may be slightly off or dated (is there a
> "newsletter" we don't know about beyond the website?), this is
> clearly an endorsement from a pretty big player in the experimental
> category. Yeah, Lancair is "small" compared to Vans, but I think it's
> number one among the more "modern" composite players. FWIW.
>
>
>
________________________________________________________________________________
| From: | "Charles Heathco" <cheathco(at)comcast.net> |
| Subject: | Echo in head sets with 2 ANR plugged in |
I noticed this problem a while back, but didnt tie it to the condition until second
time it was a factor. If Im alone, or psgr has non ANR headset, no problem.
Two ANR headsets and get a feedback type of echo when comm with each other.
I have a mono flight com 403. I think it is suspect and wondered if anyone else
had this problem.
Would an upgrade to say a sterio PS enginering eliminate this problem? charlie
heathco
________________________________________________________________________________
| From: | Dj Merrill <deej(at)thayer.dartmouth.edu> |
| Subject: | Re: Tap into antenna coax? |
Dr. Andrew Elliott wrote:
> My planned use would be to have *either* the primary comm *or* the
> backup radio turned on at any time, never both. Is this idea OK???
> Will it work???
>
> Andy Elliott
Hi Andy,
I'd be concerned with the transmit power of the
first radio going directly into the receiver of the
second radio. Not sure if having it powered off would
be adequate, and if you ever accidentally left it
on you would likely fry the receiver in the other radio.
Narco used to make a relay device that let
you use two radios with one antenna. I have one
somewhere here in a box that I'd be willing to let go
relatively cheap ($20+s/h), but as I just moved most of my
life is still in a box, so I don't know exactly
where it is at present.
Rather than use the relay, I ended up installing
a second COM antenna. It was relatively cheap - I think
I paid around $70 for the antenna and the install was
easy. I helped with the installation in the Cessna 150
and I think the total bill was around $100.
-Dj
--
Dj Merrill
deej(at)thayer.dartmouth.edu
"TSA: Totally Screwing Aviation"
________________________________________________________________________________
| Subject: | Re: Tap into antenna coax? |
| From: | "Craig P. Steffen" <craig(at)craigsteffen.net> |
> I recently ripped out all the 25-30 year-old avionics in my plane and
> installed a modern all-in-one box. Now I would like to semi-permanently
> install a T-type tap at the antenna end of the coax for my primary comm.
> The idea would be to have a second coax run going to the handheld I keep
> for emergency backup.
>
> My planned use would be to have *either* the primary comm *or* the
> backup radio turned on at any time, never both. Is this idea OK???
> Will it work???
NO. In general, this will not work.
For receiving, half the power of the incoming signal will go down each
of the branches. The loss of that much signal is probably tolerable,
but...
I don't know that transmitting would work at all. Say you're using
the primary radio, and nothing was plugged into the handheld line.
When the signal hits the T-fitting, part of the signal goes out the
antenna, and part of it goes down the other branch. It reflects off
the empty and, reflects back down it, and then goes out the antenna
_out of phase_. The physics of the wave propogation in the cable is
similar to sound propogation inside of a tube. If you cut a hole in
the side of a trombone and fasten on a 6 foot long piece of PVC pipe,
you'll still get sound out, but it won't be at the right pitch, and it
won't sound like a trombone.
If you have spare radio plugged in and you're using the primary radio,
it might work somewhat. I don't know how the receive part of a radio
is wired; it might have the termination resistor across the contacts
at all times, in which case it would absorb the reflections I
described above. However, at best, you're still only transmitting
half the energy of the primary radio out the antenna; half of it's
going into the handheld. And be absolutely sure that the termination
resistor in the handheld can absorb half of the transmitting power of
the primary radio.
It's possible that there's something that I'm missing, and it actually
would work, but I think it's very prone to messing things up and it's
unlikely to ever work quite right.
Craig Steffen
--
craig(at)craigsteffen.net
public key available at http://www.craigsteffen.net/GPG/
current goal: use a CueCat scanner to inventory my books
career goal: be the first Vorlon Time Lord
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Tap into antenna coax? |
Another option ...
King used to make an adapter for their KX99 Handheld that can be used.
Basically the mini jack/plug arrangement opens the coax from the panel and
closes the connection to the handheld. It is all done in a neat little box
and you get a mini->coax pigtail.
Don't know if they still sell them or not.
James
| -----Original Message-----
| From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
| aeroelectric-list-server(at)matronics.com] On Behalf Of Dr. Andrew Elliott
| Sent: Sunday, March 20, 2005 10:05 AM
| To: aeroelectric-list(at)matronics.com
| Subject: AeroElectric-List: Tap into antenna coax?
|
|
|
| I recently ripped out all the 25-30 year-old avionics in my plane and
| installed a modern all-in-one box. Now I would like to semi-permanently
| install a T-type tap at the antenna end of the coax for my primary comm.
| The idea would be to have a second coax run going to the handheld I keep
| for emergency backup.
|
| Although it is fine in the local area, the heavily loaded short whip
| antenna the handheld comes with doesn't work very well in cruise at
| altitude, especially here in the SW where there are long stretches of
| really empty country. Hooked to a regular comm antenna, though, it is
| sufficient.
|
| My planned use would be to have *either* the primary comm *or* the
| backup radio turned on at any time, never both. Is this idea OK???
| Will it work???
|
| Andy Elliott
| N481HY/AA-1(TD,160)/KFFZ
| That's "One Hot Yankee"
| http://members.cox.net/n481hy/
|
|
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Points for discussion OVP//more |
>
>Thanks for your comment.
>
>For the record I repeat what I have said in the past.
>
>"Bob has contributed more than ALL the others combined for the homebuilders
>electrical wiring systems"
>
>That does not mean everything suggested should be used blindly nor is
>everything the best in today's world.
>
>I doubt that many realize the huge currents (and I have documented 400 amps
>+ many times) that can be produced by the OVP and frankly likely with the LR
>series of external regulators. I can find nothing suggestion the possibility
>of such currents and the potential for side affects. As a extremely simple
>mod reduces the peak current to reasonable values and does nothing to the
>functionally of the OVP I simply find Bob's resistance strange to say the
>least. 25 amps will pop the fuse nearly as fast without the potential side
>affects.
Please my friend, how did you get 400 amps? Let's postpone any discussions
about how the science is applied. Let's assume we're talking about fault
currents downstream of ANY over-current protection device be it fuse,
breaker or electro-whizzy. Let's assume the fault can come from a variety
of instances not the least of which are wires contacting the airframe
or even a crowbar ov module. Where would I "fix" the experiment cited
to approach the fault currents you're citing . . .
What I'm suggesting . . . and attempting to illustrate is the
detail level of understanding of underlying principals upon which
every product should be crafted irrespective of its application
or comparative performance with other products.
BTW I have often
>sent builders to Bob for design and building methods for their electrical
>system with the exception of those with an electrically dependent aircraft
>where Bob has not completely addressed the issues unique to an engine that
>needs 10-20 amps just to run and cannot stand even momentary battery
>terminal voltage under approx 11.0 V.
There are two separate issues here. Need to support an engine's
energy requirements and the need to maintain bus voltage above
some level for minimum performance of some product.
We already know of several popular products where the
designers have chosen to ignore or just didn't appreciate
the value of considering a wealth of tribal knowledge that
precedes their endeavors . . . not the least of which are
DO-160 recommendations. If a builder chooses to use these
products, separate battery support is required and it
doesn't matter who is the low voltage antagonist be
it starter motor, landing gear pump, air conditioner
drive motor, or crowbar ov protection module or a short
somewhere in the electrical system.
If one wishes to embrace these products as standard bearers
for "modern electronics" and overlook relaxation of
design goals for "yesterday's electronics", it's certainly
their right. These are experimental airplanes and I hope
the remain so for ever. The risk is that relaxation of
common practice for yesterday's electronics in today's
electronics may lead to further relaxation in tomorrow's
electronics. In my never humble opinion, this is not
progress or even maintenance of the best we know how to
do today.
I'm pleased to note that our friends down at Emagair
have crafted an ignition system that will allow one to
prop an engine using a battery that is too weak to even
close its own battery contactor. How cool is that?
Hey you guys at Slick . . . put that in your Unison pipe
and smoke it! Well, fooey. I jumped off the science
wagon myself and fell into the philosophy puddle
. . . my apologies.
I think it's important to bring our constituents up to
speed on the science before we analyze philosophy.
I'm posting the next revision to the science white paper
this afternoon sometime.
Bob . . .
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Tap into antenna coax? |
James E. Clark wrote:
>
>Another option ...
>
>King used to make an adapter for their KX99 Handheld that can be used.
>Basically the mini jack/plug arrangement opens the coax from the panel and
>closes the connection to the handheld. It is all done in a neat little box
>and you get a mini->coax pigtail.
>
>Don't know if they still sell them or not.
>
>James
>
snipped
You can make one of these for yourself if you're handy with a soldering
iron. Jim Weir actually described construction in an old Kitplanes article.
http://www.rst-engr.com/kitplanes/KP0203/KP0203.htm
The design won't make HAM radio guys or RF engineer types happy, but it
works fine considering the limited use it will get. If you're really
worried, put it in a little aluminum box.
Charlie
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Points for discussion OVP//more |
There certainly isn't any automotive based stuff that doesn't run well
below 11 volts or many cars would never even start. If the goal is a
21st century power source then perhaps the systems that use electricity
should also catch up to the automotive world. Mine has because it is
automotive.
Ken
>BTW I have often
>sent builders to Bob for design and building methods for their electrical
>system with the exception of those with an electrically dependent aircraft
>where Bob has not completely addressed the issues unique to an engine that
>needs 10-20 amps just to run and cannot stand even momentary battery
>terminal voltage under approx 11.0 V.
>
>
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: Tap into antenna coax? |
Would it work to tape a rubber ducky antenna outside a gear leg fairing to
test out the handheld for xmit/rec? If it worked it could then go inside
the fairing for more permanent use. Has anyone tried this?
Jerry
> Dr. Andrew Elliott wrote:
>
>> My planned use would be to have *either* the primary comm *or* the
>> backup radio turned on at any time, never both. Is this idea OK???
>> Will it work???
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Points for discussion OVP//more |
>
> >Paul wrote:
> >A developer of a new avionics system who only looks at certificated
> > aircraft will not notice your design, nor will those who also inquire
> >with major experimental aircraft manufacturers like Vans.
>
>Hmm... the top composite experimental (Lancair) says in its IVP
>manual, its ES manual, and its recently updated Legacy manual (see
>http://www.lancair-kits.com/manual_revisions/Legacy_manual_rev-0105.pdf,
>p. 27-4):
>
>"Robert Nuckolls is also an excellent reference for wiring. He
>publishes a newsletter,
>The AeroElectric Connection, and also contracts his services to
>individual builders to design custom electrical schematics. He can be
>reached at:
>
>Medicine River Press
>6936 Bainbridge Road
>Wichita, Kansas 67226-1008
>(316) 685-8617"
>
>While specifics of this may be slightly off or dated (is there a
>"newsletter" we don't know about beyond the website?), this is
>clearly an endorsement from a pretty big player in the experimental
>category. Yeah, Lancair is "small" compared to Vans, but I think it's
>number one among the more "modern" composite players. FWIW.
Yes, this is VERY dated info but not particularly relevant.
This isn't a contest and there's no value in tallying up
votes for or against any particular philosophy or champion
of that philosophy.
I'm reminded of a plaintiff attorney who once made the
statement, "You guys only have two witnesses who stated
that the engineer blew the whistle and I have a dozen
witnesses to state that the engineer didn't blow the
whistle. Therefore I win by 12 to 2"
The statement illustrates the total lack of logic that
says just because a person does not perceive the
sound of the whistle, does not mean with certainty that
it did not blow. However, if only only one honorable
witness heard the whistle and testifies as to fact,
then without a doubt the whistle DID blow.
Lets focus on facts as deduced by repeatable experiment
and then build a philosophy on those facts.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: OV protection debate |
>
>I did testing that included all you seem to want in the Load Dump study.
>
>I setup a simple but complete electrical system (using real sized wiring and
>gauges) from battery to running alternator. For the OVP testing I tested 3
>different CB styles from 2 mfgrs to verify the data.
>
>I have several hundred photos and many pages of test results that are on the
>slow path to being on my web site.
Paul,
Please don't mistake my activity as a tool attempting to
flog you into action nor is it intended to chastise you for inaction.
Please take care of important business. We all have to make
decisions as to the best use of our most limited resource . . . $time$.
The effort I put into the current work probably wasn't so much
a better use of $time$ from perspective of return-on-investment
as opposed to a break from the frustrations of trying to design/fix
parts of certified ships while working within the mandated framework
of a committee . . . most of whom to not understand what I do.
Revision -B- to my paper will publish today . . . revision -C-
is some time in the future and perhaps even never. Please don't
react to it in any manner except as a critical reviewer capable
of spotting bogus science and errors.
>I have taken a lot of heat from Eric on publishing the complete report but I
>have so little time and so much to do. Eventually is what #2 priority gets
>:-) If one only publishes parts there are unanswered questions that remain.
>Also I dislike to report in pure engineering terms as there are so few that
>would understand what I am saying and so many that need to hear it in
>general english.
Aw . . . tell Eric to get himself a beer and go out on
the deck with a good book. All good things will come
in due course. I agree on the hazards of trying to communicate
in the academic vernacular. My technical leader at RAC recommended
a paper on leadership to all of his subordinates about a week
ago. This thing was about 6 pages long and my eyes were glazed
over after the first page . . . I'm writing my own paper on
qualities of leadership which I will submit back to him and
ask for critical review. "Hey boss, how does the paper you
cited differ this one?" Mine is about done and is only 2 pages
long . . . and uses no words that the average engineer at
RAC should have to look up in the Dictionary of Vague Terms.
By all means, when your work IS ready for critical review,
please word it in a manner that all discussions leading out
of it can include the majority (if not all) of our friends here
on the List.
Bob . . .
> > Would it maybe not help solve some of this debate as to the OV
> > protection if perhaps Eric, Paul, and Bob all drew up their
> > favorite OV protection circuit, and maybe one or all of them
> > took the time to actually run them and produce a situation
> > that would cause trouble? I know Bob ran his circuit to
> > prove his....
No Tim, this wasn't the intent of the first issue of
the white paper . . . nor is it the intent of the
issue out today . . .
> > . . . but I'd be interested to see a couple of different
> > OV options, and graphs of voltage and current spikes that
> > happened when an OV condition was created. It seems like
> > all of this debating back and forth could be settled
> > with just a few hours of directly compared experiments...
We're working up to that. Far too much water has already
run under the bridge roiled up by bad science and
personal interpretations/emotions.
This is a multi-layered experiment . . . bottom layer
is the science of the philosophies offered. Several
other layers exist in between but the layer is an
experiment to offer readers of this list what I
hope is a valuable tool: An illustration of how any
useful philosophy worth adopting must be supported by good
science first.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
>
>If the internal regulator gets all its power from the field lead then
>opening this lead stops the alternator output current. I have modified
>several brands to eliminate the internal "B" lead to regulator connection
>and then the only "B" lead protection is a fuse. Not easy to do on ND brand.
>
>GOOD alternator internal regulators have adequate load dump protection built
>in. Why Vans fail when coupled with OVP and not just Bobs is a mystery at
>present. Vans has no answer.
A KEY perception. Van's wasn't incorrect in their description
of circumstances surrounding the failure events . . . yes, the
alternators WERE fitted with b-lead disconnect contactors and
OV protection.
Further, their reaction is quite understandable. If
you stick your hand through a hole and pull back some bloody fingers,
the simplest remedy is to suggest "don't put your hand through that hole".
But if a useful feature of your airplane is accessed through that
hole, then you are encouraged to deduce what's wrong with the design on the
other side. For whatever reasons, Van's chooses not to join that
investigation and that's fine. It's not their venue of expertise
and things about which they choose to acquire expertise are done very well.
>However its not necessary to disconnect the "B" lead when the alternator is
>running except in a failure mode. It should never be done as a matter of
>testing in my opinion.
Agreed. In fact, a concern that has/needs to be investigated
is what happens to a failed alternator if the b-lead connector
is opened in response to regulation failure. It seems that it
would continue to run self-excited in the runaway mode and
probably smoke the field winding or short some diods. While an
b-lead disconnect will certainly save the rest of the system,
is their an elegant solution to keeping a $5 part in an alternator
from forcing the destruction of other perfectly good parts in
the alternator.
Bob . . .
> > Matt:
> > "If a device that simply opens the B lead is enough to damage the
> > alternator, it doesn't sound like the real reason is the OVP module
> > (although it is possible it could make a problem more likely). It
> > suggests to me that these alternators should not be disconnected at all
> > once running, and if you want the ability to do that maybe they are not
> > suitable. Of the thousands of aircraft flying without failures, how many
> > have tested what happens if the alternator is disconnected?"
Matt . . . very good question which I touched on above.
> >
> > I agree. The alternators that Van's sells probably are ones which
> > don't source the field current through the sense wire. They are probably
> > automotive derivative and as such, running without a battery wasn't one of
> > the design parameters.
>
> > Operationally, the risk of damage from a disconnect can probably be
> > minimized. Take actions which disconnect the b-lead only when the
> > loads and possible output are low. Don't cycle the alternator on a cold
> > night when all the lights are on and the engine is turning cruise RPM.
Correct. You wouldn't do this in your Cessna . . . why do it
in your RV?
> > Whether an alternator which supplies its field current through the control
> > wire should be installed with a b-lead contactor is debatable. If I use
> > an alternator that has internal regulator, it will have the contactor. I
> > don't know what the fail modes in the regulator are.. Is there another
> path for
> > excitation to get through?
The question would more properly focus on the b-lead to field
path internal to the alternator that works INSIDE the b-lead
disconnect barrier which precipitates further damage onto an alternator
after the regulator fails.
I've seen alternator schematics that show a zener diode downstream
of a fuse INTERNAL to but in series with the b-lead supply to the
field. The schematic didn't reveal component values but it suggests
a practical way to build some protection of the alternator field
into an alternator used with a b-lead contactor. If the voltage
after opening the b-lead contactor continues to rise (to some
value with healthy head-room - like 20-25 volts) then the zener
shorts and the fuse opens protecting the alternator from self
immolation.
Bob . . .
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: [Fwd: [FlyRotary] Re: Alternators] |
Bob,
This showed up on another list & some would like to see your comments,
since you are directly involved in certified hardware. I'm pretty sure I
could write more about the inconsistencies here than he's written about
the differences, but I'd also like to see your opinion. I'll post back
to the other list if that's acceptable.
Thanks,
Charlie
Begin quote:
From Pifer's Airmotive, Inc. Pontiac MI
DIFFERENCES BETWEEN AIRCRAFT & AUTO ALTERNATORS USING A FORD BELT DRIVEN 12v
OR 24v ALTERNATOR FOR A COMPARISON
1. Although alternators are bi-rotational, aircraft engines turn opposite of
automotive. This means cooling fans must be canted in the opposite direction.
Also, pulley and belt size vary due to coming-in speed.
2. The thru bolts are of a higher tensile strength utilizing an
anti-rotation
device in the form of a lock tab. The rectifier assembly has a heavy duty
diode with higher voltage and amp. capacity. Also, one excites at 90 PIV (Peak
Inverse Voltage) and the other at 150 PIV. Radio suppression is designed for
108 frequencies and up which is the VHF and 108 and down which is FM band.
3. The brushes have a higher graphite content and they utilize a tin plate
on
the brush leads to prevent corrosion.
4. The stator is of the Delta wind rather than the Y" wind and it does not
utilize the stator terminal. The aircraft unit also carries H" insulation
which is capable of 200 degrees centigrade temperatures. It also is rated at
60 amp. instead of 55.
5. The rotor has a shorter shaft and a smaller thread size. Because of the
opposite rotation it is wound in the opposite direction. It also uses "H
insulation and Havel varnish.
6. The front and rear housings are the same as automotive.
With this brief description, I hope I have enlightened you on the
differences
between aircraft and automotive alternators. Using automotive units in an
aircraft creates a potential safety hazard as well as a short alternator life
and unreliability.
End quote
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Using a 115 volt 400 hz device in a 12 |
>
>
>
> >
> > A few years hence, someone decided that we could eliminate
> > an expensive heavy drive system if devices requiring AC
> > power could be made to accept a wider range of frequencies.
> > Transformers can be designed with 400Hz windings and core
> > magnetics but fabricated from 1000Hz materials with respect
> > to losses and guess what? The thing runs fine over range
> > of 400-1000 Hz.
> >
> > This is the philosophy of choice for new systems design
> > and has been in place now for perhaps 20 years or more.
> >
> > Bob . . .
> >
> >
> >
>Bob,
>Just for curiosity, what frequency is generated by alternator (before
>rectification) in a typical Cessna in cruise conditions?
>Jerzy
It's been a very long time since I had a "scope" on an
alternator and (of course) the gear/pulley ratios between
crankshaft and alternator have a profound effect on the
frequency as does the number of poles in the stator and field.
I seem to recall measuring numbers in the 200-400 Hz range
for boss-hogg 100A Teledyne alternators on a big recip
Cessna Twin. I was looking at rewinding the alternators
with a lighter 28v winding and using the space opened up
to add a low current, 200 volt winding to bring
3-phase AC out for windshield heating. I don't recall the
exact numbers now but my best guess is perhaps 200 Hz
at ramp idle on a gear driven alternator up to a 1000 Hz
or more on a belt driven, small pulley alternator on the
front of a Lycoming at cruise.
After my test stand gets set up, I'll be able to get
some better and more current data.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: care and feeding of batteries |
>Right. But I still hold that batteries need not fail in 18 months if
>properly treated.
Quantify "failure" . . .
I've had builders walk up to the B&C booth at OSH and extolling
the virtues of "a B&C's battery still going strong in my
airplane after 5 years". Bill was delighted that folks standing
at the booth took reverent notice . . . I had to bite my tongue.
The guy flying that five year old battery was able to crank
the engine to get the ship to OSH. Had he experienced an
alternator out condition on his way to OSH three years ago
he might well have considered the battery "failed" when
it didn't get him back on the ground comfortably.
> >> OTOH, there is no reason that a properly cared-for battery shouldn't
> >> provide 90% capacity at 5 years. If viewed that way the extra
> >> complexity starts to look like break-even. Hey, guys are buying the
> >> Unison/Slick electronic magneto system.
> >
> > Again, not enough data to support the premise. I have
> > "properly cared for" batteries in my shop that are well
> > over 5 years old. They're deep cycle batteries used in
> > instrumentation systems. Each one has been used to about
> > 50% capacity perhaps a dozen times. They sit on Battery
> > Tenders the rest of the time. If those batteries
> > were in constant use . . . say discharged to 50% twice a
> > week . . . I can guarantee that they'd be sent to the
> > recycling pile a couple of years ago.
> >
> > 100 deep discharge cycles spread over 5 years is 20 cycles
> > per year. One every two weeks. How often do you pull your
> > batteries down to less than 50% charge?
>
>On my boat? My normal daily cycle is about 25%-30% discharge. Every
>couple of months I pull them down to about 70% discharge to check that
>they are still delivering normal capacity. Deka claims that I should
>see 600 cycles to 80% discharge and 2100 cycles at 25% discharge. So I
>should still see something close to a 5 year life at these rates.
Boat and RV batteries are designed for deep cycle service as are
golf cart and fork lift batteries. The some of the Odyssey batteries are
thin plate, supper crankers and not as well suited to deep cycle
service. Bottom line is still that unless a battery user chooses
to TEST a battery periodically for capacity and compare that to
his/her individual requirements for capability, the true service
life of a battery is something of a crap-shoot.
I have to strongly protest non-quantified, non-specific
application advertisement of ANY battery . . . particularly
those touted for their cranking and cold-weather abilities.
There's more to running a railroad that shoveling coal into
the firebox and more to battery selection and maintenance
than picking one that gets that tired ol' untuned engine
running on a cold morning.
> >> It shouldn't be all that difficult. Three-stage charge regulators for
> >> the marine and RV markets are less expensive then the B&C VR by a long
> >> way. Some even include current and/or temperature sensing to limit
> >> the output of the alternator to a safe level.
> >
> > Keep in mind that the B&C "regulator" is an alternator
> > control system. It includes ov protection and low voltage warning.
> > This works out to three gizmos in one box for $75/gizmo. Yeah,
> > if the only task was to regulate the voltage based on some
> > scheme designed to enhance battery life, we could produce such
> > a device for a whole lot less than $225.
>
>And the three-stage regulators are a charge control system. What's in
>a name? OTOH, once you put in the microprocessor you can combine some
>of the functions to reduce parts count.
Yup, there are some really interesting products coming over
the hill. Very capable and good value too. I told
Bill this was coming 10 years ago and encouraged him to have
a replacement product on the back burner for introduction
5 years ago. He has decided to invest IR&D $time$ in other
products.
I suspect that R12 or at latest R13 of the 'Connection will
have to show the LR series regulators from a historical
perspective and recommend some more modern offerings as
products of choice.
Bob . . .
________________________________________________________________________________
| From: | "Jon Finley" <jon(at)finleyweb.net> |
| Subject: | Re: Subaru z-figure |
Hi Hans,
I think I've seen your electrical system schematic (maybe on the FlySoob
list) but can't find it now. Do you have it posted somewhere?
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
Apple Valley, Minnesota
http://www.FinleyWeb.net/Q2Subaru
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On
> Behalf Of Hans Teijgeler
> Sent: Wednesday, March 16, 2005 2:25 AM
> To: aeroelectric-list(at)matronics.com
> Subject: RE: AeroElectric-List: Re: Subaru z-figure
>
>
> -->
>
> Jon,
>
> Your requirements exactly match mine. Strictly VFR, Subaru
> engine and tough luck for ATC, but as soon as my alternator
> dies the radio will be switched off, no lights, no strobe, no
> tpx, no electric flaps, no electric trim, just the engine to
> feed from two batteries.
>
> I've ended up with a very simple diagram:
>
> Battery A feeds pump A, computer A and the main bus.
> Battery B feeds pump B, computer B and the starter
> One alternator tops off both batteries through some diodes
>
> No crossfeeding, no E-bus, no complexity. I know that I am
> throwing away a lot of flexibility, I know that a triple
> failure might shut me down (alternator, battery A and
> computer B broken = glider), but I can live with that. The
> reduced complexity makes up for that- for me.
>
> Thanks Bob for the preview. The diagram makes a lot of sense
> if you want to keep alive more than the engine alone. Like
> with Jon, it simply is overkill for my requirements.
>
> Hans
>
>
> > -----Oorspronkelijk bericht-----
> > Van: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> > aeroelectric-list-server(at)matronics.com] Namens Jon Finley
> > Verzonden: dinsdag 15 maart 2005 17:48
> > Aan: aeroelectric-list(at)matronics.com
> > Onderwerp: RE: AeroElectric-List: Re: Subaru z-figure
> >
> > -->
> >
> >
> > Sort of opportune moment to jump into this thread Ive been
> trying to
> > find the time to compose some intelligent questions about a simple
> > electron- dependent-engine system (Subaru).
> >
> > After studying the Z diagrams (I've not yet studied these
> sneak-peak
> > diagrams), I came up came up with the system posted on my website
> > (http://www.finleyweb.net/default.asp?id=131). This was
> designed and
> > constructed more than a year ago. Since this time Ive
> learned a lot
> > by lurking here and now understand that my system has a number of
> > weaknesses/problems (which probably means that are more
> things that I
> > dont even know about yet).
> >
> > My biggest issue/hurdle is that the relevant Z diagrams seem overly
> > complicated for my simple system. I do not have a highly complex
> > airplane nor do I have a difficult mission profile. While I
> am an IFR
> > pilot, I know that my airplane is strictly VFR. When I detect an
> > electrical problem, everything in the airplane is going to be
> > shutdown. The engine keeps running from the battery and I
> land (within
> > an hour). I dont NEED a radio, transponder, gauges,
> five-hour range,
> > etc... just need the engine to keep running for a bit. I could
> > probably babble on for a long time about this but my point
> (really a
> > request) is that I would really like to see a simple system for a
> > Subaru.
> >
> > Thanks Bob!
> >
> > Jon Finley
> > N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
> > Apple Valley, Minnesota
> > http://www.FinleyWeb.net/Q2Subaru
> >
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternators] |
>
>
>Bob,
>
>This showed up on another list & some would like to see your comments,
>since you are directly involved in certified hardware. I'm pretty sure I
>could write more about the inconsistencies here than he's written about
>the differences, but I'd also like to see your opinion. I'll post back
>to the other list if that's acceptable.
>
>Thanks,
>
>Charlie
>
>Begin quote:
>
> From Pifer's Airmotive, Inc. Pontiac MI
>
> DIFFERENCES BETWEEN AIRCRAFT & AUTO ALTERNATORS USING A FORD BELT DRIVEN 12v
>OR 24v ALTERNATOR FOR A COMPARISON
>
> 1. Although alternators are bi-rotational, aircraft engines turn opposite of
>automotive. This means cooling fans must be canted in the opposite direction.
>Also, pulley and belt size vary due to coming-in speed.
An automotive fan looses only 10 percent or so of its cooling
efficiency when spun the wrong direction. Van used to sell or
recommend an alternator that featured an external cooling
fan. He recommended removing it because it turned "the wrong
direction". Bad idea. The alternator went from a slightly
compromised fan to NO fan.
Modern alternators have bi-directional fans and I now believe
most have brushes mounted right over the slip-ring shaft center
so these alternators can be spun either direction without
concerns.
> 2. The thru bolts are of a higher tensile strength utilizing an
>anti-rotation device in the form of a lock tab. The rectifier assembly has
>a heavy duty
>diode with higher voltage and amp. capacity. Also, one excites at 90 PIV (Peak
>Inverse Voltage) and the other at 150 PIV. Radio suppression is designed for
>108 frequencies and up which is the VHF and 108 and down which is FM band.
The gentleman may indeed be looking at the specifications
for some "certified" alternator. Further, the datasheet may
be some revision printed in 1975 . . . It's difficult to know.
Radio noise from alternators is not a big issue at VHF
comm and nav frequencies. ADF and LORAN are the vulnerable
systems. Many (if not all) of the alternators I've seen torn
down over the last 5 years have hi-quality filters built in.
AM radio receivers are the vulnerable system in cars and it's
not difficult to include such filtering in the alternator's
basic design. I doubt anyone even makes a diode that won't run
at 200 volts plus. This used to be a big deal but it's so easy
to craft a diode that nobody worries much about tailoring one
for a low voltage application. Thru bolts are NOT an issue. The
automotive conversions have run quite well by the thousands
of installations over a decade.
Certified aircraft alternators crap with regularity. The
vast majority of B&C alternators sold over the past 15 years
are still running as original installation parts.
> 3. The brushes have a higher graphite content and they utilize a tin plate
>on the brush leads to prevent corrosion.
Bull hocky. Corroded brush leads are the very LEAST of one's
concerns for brush life . . . don't know about the "graphite content"
and can't imagine why it's an issue on slip rings.
> 4. The stator is of the Delta wind rather than the Y" wind and it does not
>utilize the stator terminal. The aircraft unit also carries H" insulation
>which is capable of 200 degrees centigrade temperatures. It also is rated at
>60 amp. instead of 55.
Also bull hockey . . . one can wind the stator any way they
wish to take advantage of some feature that gives is preference
over another. I've read the sand-sifting offered by several
folks on this subject but there are alternators wound both
ways that perform just fine. Some older airplanes use the center
tap "stator" terminal to drive an alternator failure warning system
but this is super-antiquated. With a low voltage warning lamp, you
can deduce everything the pilot NEEDS to know about altenrator
performance whether the thing is Y or Delta wound.
> 5. The rotor has a shorter shaft and a smaller thread size. Because of the
>opposite rotation it is wound in the opposite direction.
Yes, the nuts retaining the pulley on an ND alternator running
in an airplane are put on with an impact wrench. Sometimes
the pulley is keyed to a flange on the shaft which makes thread
direction irrelevant for pulley retention. Alternator shaft torques
are so low that clamp up forces on a properly installed nut
totally negate any sensitivity to direction of threads.
>It also uses "H insulation and Havel varnish.
Everybody used class "H" insulation. An automotive alternator is
more likely to run at temperature limits than anything on an airplane.
Cars don't get the benefits of lower ambient temps and 100+ MPH
ram air if needed.
> 6. The front and rear housings are the same as automotive.
>
> With this brief description, I hope I have enlightened you on the
>differences between aircraft and automotive alternators. Using automotive
>units in an
>aircraft creates a potential safety hazard as well as a short alternator life
>and unreliability.
My sense is that the data being offered is outdated and features
offered as uniquely "aircraft" because the product has been spec'd
onto somebody's type certificate are overblown or irrelevant to the
application.
Given the DEMONSTRATED service life of modern automotive alternators
on OBAM aircraft and exemplar performance in automobiles, I venture
to say that one wouldn't want to put an "aircraft alternator" on a
car. They're expensive, fewer folks stock them, even fewer folks have
parts for them and they don't last as long.
I'd opt for an ND alternator modified to run external regulator
for ANY belt driven certified alternator any day.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Tap into antenna coax? |
Don't know how long Jim's had his butt-ugly hand held antenna adapter
article posted. My own version is at:
http://aeroelectric.com/articles/commtap/commtap.html
HOWEVER, the top paragraph of my article cites the preferred way
of breaking into the feedline for your comm antenna . . . put a
male/female junction in the feedline with some excess coiled under
a seat or behind a velcro'ed upholstery panel. The coax "T" will not
work and puts one or both radio's receivers at risk for damage by
the other radio's transmitter.
Bob . . .
>
>
>James E. Clark wrote:
>
>
> >
> >Another option ...
> >
> >King used to make an adapter for their KX99 Handheld that can be used.
> >Basically the mini jack/plug arrangement opens the coax from the panel and
> >closes the connection to the handheld. It is all done in a neat little box
> >and you get a mini->coax pigtail.
> >
> >Don't know if they still sell them or not.
> >
> >James
> >
>
>snipped
>
>You can make one of these for yourself if you're handy with a soldering
>iron. Jim Weir actually described construction in an old Kitplanes article.
>http://www.rst-engr.com/kitplanes/KP0203/KP0203.htm
>The design won't make HAM radio guys or RF engineer types happy, but it
>works fine considering the limited use it will get. If you're really
>worried, put it in a little aluminum box.
>
>Charlie
>
>
>--
>Checked by AVG Anti-Virus.
>
>
>-- incoming mail is certified Virus Free.
>Checked by AVG Anti-Virus.
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Crowbar OV Protection |
>
>My question refers to the VR-166 Ford type voltage regulator with an
>alternator B+ to regulator terminal 'A' connection supplying alternator
>field current. When the crowbar protection reduces VR terminal 'S' to under
>2 volts, is the field current supply via terminal 'A' always interrupted? I
>presume that the answer depends on the failure mode of the VR-166 that
>caused the crowbar to 'fire' in the first place.
>
>In other words, with the old mechanical VR-166, I have confidence that the
>crowbar protection is adequate. Substituting an electronic VR-166 (with the
>B+ to terminal 'A' wire, not with terminal 'A' and 'S' jumpered per Bob's
>diagrams) seems to create the equivalent of an alternator with an internal
>voltage regulator.
How so? Trace the connection between B-lead and field supply if
the master switch or field supply breaker are open?
>Hopefully, alternator field current via VR termimal 'A', with terminal 'S'
>de-energized, is a low probability VR-166 failure mode? Anyone really know
>???
Some if not most solid state clones of the original Ford
electro-mechanical regulator are form, fit and function
replacements. The original electro-mechanical regulator had
only a voltage regulator 'relay' and could have been made
to function without a field relay. See
http://www.aeroelectric.com/Pictures/Ford_EM_Reg.jpg
http://www.aeroelectric.com/Pictures/Ford_EM_Reg_Field_Relay.jpg
http://www.aeroelectric.com/Pictures/Ford_EM_Reg_Volage_Relay.jpg
The field relay monitored voltage at the stator tap of a
"Y" wound alternator. An alternator fail indicator lamp
was wired across the open contacts of the field relay.
The 100 mA or so of lamp current would excite the alternator
enough so that the alternator would excite and bring the
stator center tap up to about 1/2 bus voltage. "S" on
the regulator was the field relay coil connection and
went to "S" on the alternator stator winding.
Cessna simply used the "S" terminal on the regulator
as a field control and turned the relay on/off with
1/2 of the split rocker. Later, the OV protection
went into this lead.
When the solid state clones came out, there was
and intense desire to eliminate all forms of relay
and this is an exemplar product:
http://www.aeroelectric.com/Pictures/Ford_SS_Reg.jpg
http://www.aeroelectric.com/Pictures/Ford_SS_Reg_open.jpg
Look ma! No relays.
Problem was that some "forward looking" designs used
the old "S" terminal for bus voltage sensing instead
of field CONTROL . . . field source came in through "A"
like always. However, when dropping voltage on "S", instead
of opening a relay that REALLY shut the alternator
off, the regulator instead senses low bus voltage and
full-fields the alternator. Tried one of these
regulators to test the alternator system in a Cessna
and was surprised to find that shutting off the master
switch did NOT kill the alternator but in fact, produced
a design induced OV runaway.
Hence, all my drawings that utilize the generic Ford
regulator tie "A" and "S" together and run those off
to the bus via the master switch and alternator field
breaker. No problems will be encountered with this
wiring philosophy irrespective of the regulator you
find laying around.
Getting back to your original question: When wired as
shown in Z-23, as soon as the SCR in the ov module
fires, field supply to the alternator chokes off at
2 volts or less and the alternator begins to go to
sleep even before the circuit breaker trips. When it
does trip, the dragon fires are completely dead.
Bob . . .
________________________________________________________________________________
| From: | "Dan O'Brien" <limadelta(at)gmail.com> |
| Subject: | Re: Re: Points for discussion OVP//more |
>>this [Lancair's endorsement of the aeroelectric connection approach]
>> is clearly an endorsement from a pretty big player in the experimental
>>category.
> Yes, this is VERY dated info but not particularly relevant.
Not RELEVANT? Ever heard of Bayes theorem? It's a basic fundamental
in probablility theory, which is fundamental to every other scientific
discipline. It's also a basic building block of rational
decision-making. If a customer believes a) Lancair knows something
the customer doesn't know, and b) Lancair is not randomly pitching
darts in drawing their endorsment, then Baye's theorem implies the
endorsement is "relevant" to the customer. This is nothing more than
probability 101.
Get it?
And by the way, your political analogies to my last two posts were,
well, political analogies that were not particularly relevant.
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: Crowbar OV Protection |
Bob, Paul, listers...
You are reading from the keyboard of a complete novice, sometimes I don't
know my + from my -- butt (pun) manage to get by with the dirt simple stuff.
With that said and trying to follow more experienced minds, in this debate,
I would like to run this idea by the jury.
I understand the drawing AND testing of circuits are now done with computer
programs. Isn't it, therefore, possible to do this OVP design work and
testing like that? If that can be done, how about a step further ... slow
down the simulated progress of the circuit so all those electrons can be
both, tracked and timed as to their behavior. Design out the problems and
build it. What could be simpler? Tell us all this can be done and for the
jury to standby. My 2 cents is standing by.
Appreciate all the talent you pros display in this debate and with best
regards ...
Jerry Grimmonpre
________________________________________________________________________________
| From: | CHAD FELDPOUCH <1pouch(at)sbcglobal.net> |
| Subject: | RE: LOCATION OF WX 500 ANTENNA |
Can anyone tell me if it will matter much if I mount a WX 500 antenna within 8
inches from an Stec pitch trim servo ? It will also be about 18 to 20 inches from
the landing gear power pack , battery and a couple solinoids . I know what
the install manual says, but this is about the only good location I have and
there would not be a place in the whole plane to meet the requirements of the
install manual . Will this work ? Also can I mount a GDL 49 , WX 500 processor
and an HSI remote gyro within 2 inches of each other and within 6 to 8 inches
from the battery and the landing gear power pack ?
Thanks,
Chad..
CHAD FELDPOUCH
FELDPOUCH AVIATION
PHONE: (618) 267-8035
FAX: (618) 283-7285
EMAIL: 1pouch(at)sbcglobal.net
________________________________________________________________________________
| Subject: | Re: Crowbar OV Protection |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi Jerry,
What you propose is a not a bad idea. Electrical Engineers use
circuit simulation software all of the time. Usually, they are used
for circuits with far more components. For an application like
this, there are limitations in the capabilities of the software,
unfortunately.
In this case, probably the biggest limitation is that simulations
depend on accurate models of the circuits they simulate. The way
the sim software that I am aware of works is that the engineer has
to draw out what the circuit looks like in terms of conductors,
resistors, capacitors, inductors, transistors, transformers, and
diodes. The key to making the software work is identifying what
components actually exist, and where. Sometimes that's a big
challenge, becuase it may be difficult to know just how much of each
fundamental electromagnetic principle is happening.
For instance, it's often difficult to model noise propagation. Let's
say two parallel conductors sit somewhat adjacent. How much do
current transients on one conductor affect the adjacent wire? That may
be difficult to predict.
Then, to make use of the model, the user has to figure out what
kind of electrical signals should be used to stimulate the circuit.
It's only slightly like a CSI simulation. :)
Even though the alternator/regulator bus circuit might seem like it has
a bunch of components, it should be rather simple model. Consider that
sims are built for circuits that have literally billions of transistors.
None the less, what you suggest is worth probably worth trying. Almost
always, something interesting is learned from attempting to build a
detailed circuit model. Who wants to break out some SPICE? I've
been away from it for so long it would take me a while.
Regards,
Matt-
VE N34RD, C150 N714BK
>
>
> Bob, Paul, listers...
> You are reading from the keyboard of a complete novice, sometimes I
> don't know my + from my -- butt (pun) manage to get by with the dirt
> simple stuff. With that said and trying to follow more experienced
> minds, in this debate, I would like to run this idea by the jury.
>
> I understand the drawing AND testing of circuits are now done with
> computer programs. Isn't it, therefore, possible to do this OVP design
> work and testing like that? If that can be done, how about a step
> further ... slow down the simulated progress of the circuit so all
> those electrons can be both, tracked and timed as to their behavior.
> Design out the problems and build it. What could be simpler? Tell us
> all this can be done and for the jury to standby. My 2 cents is
> standing by.
> Appreciate all the talent you pros display in this debate and with best
> regards ...
> Jerry Grimmonpre
>
>
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
| Subject: | RE: LOCATION OF WX 500 ANTENNA |
What kind of plane are you working on?
Jim Stone
Jabiru J450
Clearwater FL.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of CHAD
FELDPOUCH
Subject: AeroElectric-List: RE: LOCATION OF WX 500 ANTENNA
--> <1pouch(at)sbcglobal.net>
Can anyone tell me if it will matter much if I mount a WX 500 antenna
within 8 inches from an Stec pitch trim servo ? It will also be about 18
to 20 inches from the landing gear power pack , battery and a couple
solinoids . I know what the install manual says, but this is about the
only good location I have and there would not be a place in the whole
plane to meet the requirements of the install manual . Will this work ?
Also can I mount a GDL 49 , WX 500 processor and an HSI remote gyro
within 2 inches of each other and within 6 to 8 inches from the battery
and the landing gear power pack ?
Thanks,
Chad..
CHAD FELDPOUCH
FELDPOUCH AVIATION
PHONE: (618) 267-8035
FAX: (618) 283-7285
EMAIL: 1pouch(at)sbcglobal.net
=
=
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: relevancy redux |
>
> >>this [Lancair's endorsement of the aeroelectric connection approach]
> >> is clearly an endorsement from a pretty big player in the experimental
> >>category.
>
> > Yes, this is VERY dated info but not particularly relevant.
>
>Not RELEVANT? Ever heard of Bayes theorem? It's a basic fundamental
>in probablility theory, which is fundamental to every other scientific
>discipline. It's also a basic building block of rational
>decision-making. If a customer believes a) Lancair knows something
>the customer doesn't know, and b) Lancair is not randomly pitching
>darts in drawing their endorsment, then Baye's theorem implies the
>endorsement is "relevant" to the customer. This is nothing more than
>probability 101.
>
>Get it?
>
>And by the way, your political analogies to my last two posts were,
>well, political analogies that were not particularly relevant.
Hmmm . . . I'll have to ponder that a bit. Permit me to clarify
my perceptions of "relevancy" and use of the term:
There have been many purveyors of products, information and
services who have achieved some level of popular or even
critically reviewed acclaim for their efforts. I'm personally
extra-critical of acclaim embedded in the work of others.
Particularly when it's very outdated and when there has
been essentially zero participation by Lancair on this
list or through any other communication with me. Not
that I'm bad-mouthing acclaim from folks who are leaders
in their chosen skills . . . but please consider this
example.
There's a manufacturer of an up-and-coming
glass cockpit system who's popularity and loyal consumer
base might reasonably expect HIS evaluation of MY
work to be "relevant" in the scientific community.
None-the-less, we had a little tte--tte with the
gentleman a few months ago where degrees of both modest
acclaim and energetic berating could be had in the short
span of 5-6 email exchanges.
See:
http://aeroelectric.com/articles/richter/richter.html
So what relevancy should I place on either acclaim or
berating from this particular source even though
his customers seem to find good value in his products
and choose to believe he walks on water?
An contrary extreme might be illustrated
by this hypothesis: Suppose someone like Saddam Hussein
says the "Connection is the best electrical system book
out there" and because his words are faithfully repeated
through many channels I suddenly get orders for thousands
of books. While it might be good for the bank account
I cannot imagine a worse endorsement.
If you're selling high dollar sneakers, then acclaim
from anyone having name recognition seems to boost
the sales of those shoes whether or not the individual
making the endorsement wears or even likes the product.
I'm VERY pleased for the positive support from a
company like Lancair. I'd be equally pleased to have
positive support from Blue Mountain. But in ANY and
ALL cases, relevancy of the support has more to do with
mutual understanding of the topic of interest and
less to do with how many books I've sold, how many
glass screens he's sold, how well their airplanes
fly, or how many acolytes any of us have acquired.
In the case of both Lancair and Blue Mountain, I
can attest to very little or no mutual understanding
of what transpires here on the List or in my published
works.
This is how I evaluate relevancy of acclaim as a scientist,
engineer and teacher. Others are certainly free to place their
own boundaries on the meaning of the term. But in any
instance my friend, please know that I wasn't whacking
on you.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Crowbar OV Protection |
>
>Bob, Paul, listers...
>You are reading from the keyboard of a complete novice, sometimes I don't
>know my + from my -- butt (pun) manage to get by with the dirt simple stuff.
>With that said and trying to follow more experienced minds, in this debate,
>I would like to run this idea by the jury.
>
>I understand the drawing AND testing of circuits are now done with computer
>programs. Isn't it, therefore, possible to do this OVP design work and
>testing like that? If that can be done, how about a step further ... slow
>down the simulated progress of the circuit so all those electrons can be
>both, tracked and timed as to their behavior. Design out the problems and
>build it. What could be simpler? Tell us all this can be done and for the
>jury to standby. My 2 cents is standing by.
>Appreciate all the talent you pros display in this debate and with best
>regards ...
Yes, all this stuff can be and is indeed accurately simulated. In fact,
the next installment to the White Paper will take advantage of some
computing as an aid to the analysis. But before the computer can
do good work, the models have to be accurately entered for each
component. Things under discussion now about the effects of internal
impedance, wiring resistance, battery behavior, etc. must all be
deduced and properly modeled or the simulation will be at least suspect
and possibly useless (garbage in, garbage out).
I find herding electrons on the bench and recording results with
'scope and camera is a better way to share simple-ideas with
a range of individuals having many levels of understanding. It's also
useful to do the touchy-feely thing with the hardware and
tools as opposed to running any simulation no matter how
well crafted. After years of designing and building products
I'm still surprised at the appearance, shape and feel of
a new etched circuit board or a machined part when I pick it
up for the first time. In spite of having stared at its
representation on the screen for hours, picking up the real
part for the first time is both a revelation and decided buzz.
The real pleasure of holding the elegant solution in your
hand or watching it do the job for a satisfied customer
is the acme of understanding and design. Simulation can
be a useful tool but for me at least will always be a tiny
part of the path between simple-ideas and satisfied customers.
Bob . . .
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
I was startled, surprised, astonished, and disappointed by what starts out
like a professional engineering report and rapidly changes into very non
engineering list of strange assumptions that are not supported by the facts
as presented by the manufacturer's data sheets.
Further the included, technically flawed, analysis fails to support the use
of any combination of parts which any GOOD analysis must do if the design is
made available as a do it your self design where any part combination is
likely to be used.
Sorry this is so long but I am only doing to this report what Bob has often
done to other reports he did not care for.
My entire career in engineering was marked with respect for and by my
associates. When one made a report of his or her test results, the rest of
us would consider the results and ask questions. If one of us wanted to
duplicate the results (I cannot recall when this was ever done however), we
would already have the details as that was always a part of the discussion.
Perhaps more important, any test results would always include an analysis of
why this result compared to the part specifications and therefore what one
could reasonably expect any random selection of parts to produce. This is
always required to validate the design for production. Never was a single
test used to validate the design. It was always supported with a worst case
analysis to validate the design for production.
I tested the OVP design dozens of times using different batteries and using
3 different CB designs from 2 manufacturers based on what parts were being
used in general aviation aircraft and commonly available to builders from
common sources like Wicks and Aircraft Spruce. My test setup was a mock up
simulation of a basic aircraft electrical system including parts, wire
sizes, and lengths. From a good battery thru common contactors (3 different
types and 2 manufacturers also normally available from AC etc) and a
operating alternator (ac motor driven) and last but not least the OVP as
described in Aeroelectric connection (this was and is the so called load
dump test series that was mostly conducted in the spring of 2004. The
specific CB used in this subject test is NOT available from these common
sources but is a good part for aircraft usage however)
The so called load dump testing we did last year rapidly expanded to EVERY
part of a basic electrical system Thus it included the OVP crowbar which is
the subject of this specific discussion
In fact there is not a single part of the subject test that represents
neither what I tested nor what might be found in any real aircraft (with the
exception of the CB). What I tested (and its detailed setup) would have been
provided to Bob (if only he had asked). This at least could have made his
test an apple to apple test for a reasonable comparison.
However in this case there are no usable conclusions other that there is
some current pulse, of some amplitude, and some trip time and neither of us
have defined the max/min parameters. I only wanted to define what was inside
the realistic range to show how ridiculous the crowbar approach was and Bob
apparently wanted to show how good it was and appeared to have set the test
up to produce a lower current pulse and perhaps a shorter time to open the
CB. Its also apparent he wanted to disprove my test results (which I take as
a personal insult to my professional career).
Bob made a test that is not like any real aircraft wiring etc and made
conclusions that were not consistent with the component's data sheets. In
fact a glance at the CB data sheet should have raised a red flag that
something was wrong as the test results of 15 ms to trip is outside the
range of 46 ms to 800 ms. at 1000% of rated current (at 25 deg C). True
the test was at nearly 3000% of rating and the data sheet only went to
1000%. However looking at the data sheet it's hard to get 15 ms as
reasonable for a typical CB. While it's possible the part was in spec it's
clearly NOT typical!
My testing quickly discovered that the very first trip in the morning at 15
C was nearly double the following trips made several minutes later. I would
guess that Bob's test results were after several dry runs to verify the
measuring equipment etc. This would have internally heated the CB and
produced, as I found out, 1/2 the cold trip time that is what one could
expect in normal aircraft operation. The temperature sensitivity is defined
on the data sheet which seems to not have been referenced. Again as the trip
time is well out of specification for any but the fastest in spec CB. Surely
one could not expect a 800ms part to trip in 15 ms even considering the
overload. As trip time is not linear with increasing loads (from the data
sheet again). If the XB was heated from recent testing and at the fast end
of the specification tolerance I can see 15ms as possible. I found that I
needed to wait nearly one hour to get valid cold trip times (and it was not
unusual to have trip times cold of over 100ms)..
In any event I have no reason to question Bob's test results. Bob has not
offered me the same courtesy which is unfortunate. (6 other experienced
engineers have and 2 actually inspected the setup and witnessed the testing,
all concurred with my test setup and results 400 amps and 50 ms or longer
time to trip)
Bob then goes on with "out of the thin air conclusions" :-) that are not
based on any real facts and in fact the available data (again from various
data sheets) do not support the conclusions.
For example:
From the report:
". Battery delta E for 135A load is about 2.4 volts for an internal
impedance of about 17 milliohms.
About what one would expect from a two year old battery that started out in
the 8 to 10 milliohm."
The Panasonic data sheet says approximately 12 milliohm. Approximately is
hardly an engineering term but it's also not 8-10 as Bob suggests for a new
battery.
My testing was with 2 parallel PC-625 batteries 4 years old and they have
been load tested to be like new. Each has a specified internal resistance of
7 milliohms and 2 in parallel is 3.5 milliohms Nearly 5 times lower. That
alone is a major reason why my test current was 3 times higher.
As for the greater duration of the event 15ms vs. 50 ms I suggest its likely
my parts were closed to nominal in the range of 50-500ms to start with for
the 7277 CB. If this was not the only variable it could be a simple
explanation for most of the different test results.
With the small size the OVP has a nice home taped right on the side of the
CB so there is essentially no lead resistance to deal with. I can see no
reason for the wire lengths in Bob's report.
Why 2 batteries? I was only using the design that Bob suggests for an
electrically dependent aircraft in normal operation with 2 batteries
connected together so both get charged from the one alternator. No attempt
to load the test other than to use what I feel are far better batteries but
that is another issue.
Going on we find a violation of ohms law :-)
From the report:
". Wiring drops during the crowbar event were about 8.4 volts for a loop
resistance on the order of 62 milliohms.
. Energy dissipated in the SCR during the crowbar event was E*A/t or 2.0 x
135 x 0.015 or 4 watt seconds.
Analysis:
. This experiment illustrates the ways that resistance of individual
features can stack on top of each other. 2-feet of 20AWG wire used to wire
the experiment contributes only 20 milliohms of the 62 milliohm total we
observed. The experiment has 6 crimped terminals and 6 bolted joints.
. Further, the circuit breaker when new is rated for a maximum voltage drop
of 0.35 volts at 5A or 7 milliohms
When I do the math I get 70 NOT 7 milliohms on the last line (for the CB)
which conflicts with the first line of 62 milliohms total loop resistance.
From this and my earlier comments the entire technical analysis is clearly
faulty.
There is much more I could point out with regard to faulty assumptions; but
assumption is not a term I ever allowed my engineers to make. We use real
data and cannot afford to make guesses etc. Further, and much more
important, we never allowed the use of a 'sample of one' lab test as more
than a proof of concept. Here the battery used is no where typical of what
should be used, nor are ANY of the conclusions regarding the trip times
given the wide range in the manufacturers data sheets that indicate trip
times 10-20 times longer are possible. 15 ms vs. 400+ ms is not
insignificant. Based on the SCR data sheet I expect that the mild overload
as tested here would be a gross overload with a worst case long time to
trip. 400 ms is a very long time for a 25 amp device.
If wiring resistance, CB trip times, etc are critical then this needs to be
made clear so any builder is alerted to such constraints. I know of no such
warnings.
Consider the following data from the manufacturer's data sheet on 3 of the
more popular CB that are commonly available and I tested.
I used is a Klixon 7277 vs. the Klaxon 7274 which is commonly available and
has a max voltage drop of 0.25 v vs. 0.35 v for the 7274
At 1000% the time to open is 0.028-0.550 seconds for the 7277.
At 1000% the time to open is 0.046-0.800 milliseconds for the 7274
(Both specified for aircraft use by Klaxon). Both have similar but
significantly different specifications.
The Klixon 7271 has a specified trip time at 1000% is 1.4 seconds.
The W23 is listed at 0.03 ohms +/-30%
The Trip time at 1000% is 0.25-0.6 seconds
In conclusion Bob seems to have missed my point entirely. I demonstrated
that the crowbar could produce currents of as much as 400 amps and time to
open of 50 ms (or much more). This is entirely unnecessary with a different
approach to OVP design. Even adding a 1/4 ohm resistor in the OVP module
cuts the current down to 50 amps or less which still pops the CB nearly as
fast. After all, 50 amps is 1000% overload and the maximum load specified
where the time to open is defined.
My issue is that it is not important if the current is 100 amps or 400 amps,
neither is needed for a fast trip, and is an overkill with questionable side
affects (in a upcoming post, yes there are many more issues to consider)
The parts I have selected for the 21 st century system shut down in a
millisecond at 200% of rated current or what ever limit I program into it.
No large current pulses (even 50 amps is large for a 5 amp circuit) and it
shuts down many times faster. Smaller, lighter, more reliable, and meets
much higher test standards than required in DO-160 plus its much lower cost.
I simply do not understand the massive resistance to make an improvement
(even the addition of 1/4 ohm is resisted).
Paul Messinger
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: White Paper on Crowbar OV Protection |
>
>Actually, my question was intended to be a lot more specific than that.
>I think Paul Messinger raised concerns about a load dump damaging
>regulators when the contacter is opened on the "B" lead, because the
>crowbar short drives the alternator to full output before the contacter
>opens.
>
>In the whitepaper, Bob said
>"If one uses a crowbar OV module in combination with an internally
>regulated alternator, field supply to the alternator is choked off at
>the 2 volt level as soon as the SCR fires . . . the alternator is
>already starved for field current long before the breaker opens."
>
>My question is: "Is that really true?" I can see how that would be the
>case for an externally regulated alternator, but I am not convinced that
>dropping the field voltage to 2 volts would do anything to reduce the
>output from an internally regualted alternator - which is the original
>problem.
Bad on me. That's a typo. The alternator under discussion in
that paragraph is EXTERNALLY regulated. This will be fixed in
rev C.
>I have no doubt the crowbar would protect the rest of the devices on the
>bus, but the concern is what could it do to the regulator if you open
>the B lead when the alternator is producing maximum output.
>
>I have some similar concerns about the system I will have on my Rotax,
>as the suggested design for that also has a contacter on the output
>lead, although (correct me if I'm wrong) I don't think the PM
>alternators have the same problem with load dump because they don't
>control the magnetic field.
All alternators will experience some degree of "load dump"
phenomenon. It's a function of regulator/alternator dynamics
for rapidly changing loads . . . particularly large ones
that disappear suddenly. It would really be nice to have
access to a Rotax alternator on a drive stand to explore
it's true nature but I don't see that happening soon.
Bob . . .
________________________________________________________________________________
| From: | "Hans Teijgeler" <hans(at)jodel.com> |
| Subject: | Re: Subaru z-figure |
Hi Jon,
I don't think it is the schematic that I actually have in my Jodel now that
you have seen. However, you might have seen a very old scetch that I have
posted on my web site years ago. This is the (certified) French Potez 4E20
engine, featuring coil ignition rather than magnetos. Potez solved the
dependancy on electric power by providing a split switch (labelled normal -
emergency) between the alternator and battery. The alternator would fire one
set of sparks, the battery the other one. Splitting was up to the pilot. Any
transfer between alternator and battery exceeding 7 amps was deemed
excessive and required the pilot to cut the alternator loose.
Schematics can be found at
http://www.jodel.com/index.asp?p=potezwiring&engines . Please forgive me for
the really mediocre drawing. I made it while lying on my back in a hospital
bed, yeeeeeaaars ago.
This is all 1960's stuff but seemed to work. Potez powered aircraft didn't
crash into the ground because of electrical problems. They did so because of
the engine throwing rods, cylinders, pistons, etc. :-)
Hans
----- Original Message -----
From: "Jon Finley" <jon(at)finleyweb.net>
Subject: RE: AeroElectric-List: Re: Subaru z-figure
>
> Hi Hans,
>
> I think I've seen your electrical system schematic (maybe on the FlySoob
> list) but can't find it now. Do you have it posted somewhere?
>
> Jon Finley
> N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
> Apple Valley, Minnesota
> http://www.FinleyWeb.net/Q2Subaru
>
>
> > -----Original Message-----
> > From: owner-aeroelectric-list-server(at)matronics.com
> > [mailto:owner-aeroelectric-list-server(at)matronics.com] On
> > Behalf Of Hans Teijgeler
> > Sent: Wednesday, March 16, 2005 2:25 AM
> > To: aeroelectric-list(at)matronics.com
> > Subject: RE: AeroElectric-List: Re: Subaru z-figure
> >
> >
> > -->
> >
> > Jon,
> >
> > Your requirements exactly match mine. Strictly VFR, Subaru
> > engine and tough luck for ATC, but as soon as my alternator
> > dies the radio will be switched off, no lights, no strobe, no
> > tpx, no electric flaps, no electric trim, just the engine to
> > feed from two batteries.
> >
> > I've ended up with a very simple diagram:
> >
> > Battery A feeds pump A, computer A and the main bus.
> > Battery B feeds pump B, computer B and the starter
> > One alternator tops off both batteries through some diodes
> >
> > No crossfeeding, no E-bus, no complexity. I know that I am
> > throwing away a lot of flexibility, I know that a triple
> > failure might shut me down (alternator, battery A and
> > computer B broken = glider), but I can live with that. The
> > reduced complexity makes up for that- for me.
> >
> > Thanks Bob for the preview. The diagram makes a lot of sense
> > if you want to keep alive more than the engine alone. Like
> > with Jon, it simply is overkill for my requirements.
> >
> > Hans
> >
> >
> > > -----Oorspronkelijk bericht-----
> > > Van: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> > > aeroelectric-list-server(at)matronics.com] Namens Jon Finley
> > > Verzonden: dinsdag 15 maart 2005 17:48
> > > Aan: aeroelectric-list(at)matronics.com
> > > Onderwerp: RE: AeroElectric-List: Re: Subaru z-figure
> > >
> > > -->
> > >
> > >
> > > Sort of opportune moment to jump into this thread Ive been
> > trying to
> > > find the time to compose some intelligent questions about a simple
> > > electron- dependent-engine system (Subaru).
> > >
> > > After studying the Z diagrams (I've not yet studied these
> > sneak-peak
> > > diagrams), I came up came up with the system posted on my website
> > > (http://www.finleyweb.net/default.asp?id=131). This was
> > designed and
> > > constructed more than a year ago. Since this time Ive
> > learned a lot
> > > by lurking here and now understand that my system has a number of
> > > weaknesses/problems (which probably means that are more
> > things that I
> > > dont even know about yet).
> > >
> > > My biggest issue/hurdle is that the relevant Z diagrams seem overly
> > > complicated for my simple system. I do not have a highly complex
> > > airplane nor do I have a difficult mission profile. While I
> > am an IFR
> > > pilot, I know that my airplane is strictly VFR. When I detect an
> > > electrical problem, everything in the airplane is going to be
> > > shutdown. The engine keeps running from the battery and I
> > land (within
> > > an hour). I dont NEED a radio, transponder, gauges,
> > five-hour range,
> > > etc... just need the engine to keep running for a bit. I could
> > > probably babble on for a long time about this but my point
> > (really a
> > > request) is that I would really like to see a simple system for a
> > > Subaru.
> > >
> > > Thanks Bob!
> > >
> > > Jon Finley
> > > N90MG Q2 - Subaru EJ-22 DD - 467 Hrs. TT
> > > Apple Valley, Minnesota
> > > http://www.FinleyWeb.net/Q2Subaru
> > >
> >
>
>
________________________________________________________________________________
| From: | CHAD FELDPOUCH <1pouch(at)sbcglobal.net> |
| Subject: | Re: RE: LOCATION OF WX 500 ANTENNA |
A 1978 PIPER TURBO ARROW.
________________________________________________________________________________
| From: | "Jerry Grimmonpre" <jerry(at)mc.net> |
| Subject: | Re: Tap into antenna coax? |
Trying this one again ...
Bob or anyone ...
Would it work to tape a rubber ducky antenna outside a gear leg fairing to
test out the handheld for xmit/rec? If it worked it could then go inside
the fairing for more permanent use. Has anyone tried this? (RV7A)
Jerry Grimmonpre
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
| Subject: | RE: LOCATION OF WX 500 ANTENNA |
You might want to scan the following site on how they approached a
similar problem.
http://www.bleeding.com/~jjwolf/avionics/day1/ I think the servo
location would be much to noisy and in constent operation. A skin
mapper survey is probably best bet, with empanage top of bottom being
probable candidates. Good luck with the 337 field approval.
Jim Stone
Jabiru J450
Clear5water FL.
=
=
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Alternator frequency |
<>
It's also been a long time for me, but I recall that a typical alternator
has a 14-pole rotor, giving a frequency 7 times the rpm. Also, the
alternator is typical driven at between 2 and 3 times engine speed. Given a
2500 rpm engine the frequency comes out to 730 hz. If you assumed the
frequency was between 500 and 1,000 you would probably be safe.
Gary Casey
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: OVP (Let's do what Rodney King suggested....) |
I've been keeping my head down in this OVP thing. But I am thoroughly on
Paul's side technically. I quit selling crowbars on my website entirely.
I can't even digest the voluminous postings back and forth, and have for the
most part, held off posting on this issue. My concern is that there will not
be any resolution on this issue. This may spill over into other issues.
That's bad.
Here's my suggestion---We require a small technical committee to look into
the issue, evaluate the arguments, perhaps run tests and then publish the
results. I recuse myself, and of course suggest excluding the major
combatants, although they would supply technical information and provide the
arguments.
I nominate George Braly of GAMI to head the OVP technical committee. He
seems to be a level head in these things. I suggest that George pick a half
dozen similar level-heads and communicate off line, posting progress reports
on the Aeroelectric List, then finally a complete report.
Oh yes, Rodney King said, "Can't we just all get along?"
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)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
________________________________________________________________________________
| From: | "Richard Garforth" <richard(at)hawk.flyer.co.uk> |
| Subject: | Alternator characteristics |
Just to throw in in another aspect on this topic. None of the correspondence I
have seen lately refers to the inductive issues involved with shutting down an
alternator. If you remove the field current (or reduce it to 2 volts), how long
is it before the field collapses ? Could it be long enough to sustain output
for some tens of milliseconds?
Richard
________________________________________________________________________________
| Subject: | Off-topic : MCR 4S performance with Rotax 914 |
Hi all,
Some years ago there was a discution on this list about our Dyn Aero MCR
4S project. Some expressed doubts as to the actual performance of this
Rotax 914 four-seater.
Now we are flying, and some listers might be interested in a few numbers.
We've performed some GPS runs (3-run method) at FL 120 (two on board,
with 200 liter Avgas), and obtained 157 kt TAS at 100 % power (100 hp).
The Vz is in the 1100/1300 range, and we made a climb from FL 30 to FL
140 in just 10 minutes (100 % power).
For those with a fast internet connection, a 18 MB video of our first
short take-off attempt can be viewed for some time at
http://gilles.thesee.free.fr/temp/MOV00659.MPG .
The field elevation is 1986 ft, the temperature was 5C, wind calm. Two
on board with 150 liter Avgas, weight about 640 kg (i.e. 110 kg under
max takeoff weight). Take off power 115 % (115 hp).
We still have to perform tests at gross weight but we find our little
four-seater is no sluggard !
More on the MCRs at :
http://www.dynaero.com/
http://www.avnet.co.uk/lts/
Regards,
Gilles Thesee
Grenoble, France
Website will be updated...in the near future
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator characteristics |
If you totally open the field the residual energy can last up to 150 ms or
longer depending on the external load and the presence or absence of a
battery and the way the system is physically wired. To suggest the
alternator output immediately goes to zero is technically false but it can
be a very short time if the battery connected and in good condition.
There are so many variables its hard to discuss the individual
configurations without confusion.
Consider we have internal and external regulators and in some cases the
desire to operate with no battery. Then there is the ovp method. there is
the Crowbar, a OVP that is current limited and pops the CB but with a
reasonable current. And finally the Eric Jones and recommended by me
approach where the OV is instantly clamped to a safe level and then the
alternator is taken off line and there is no chance of any post CB popping
load dump residual voltage to deal with as the circuit is clamped before
during and after. The crow bar approach takes a short time to start and may
end before the alternator finishes dumping and or the "B" lead contactor
finally opens.
The "B" lead contactor if installed takes 50 MS to open after the voltage is
dropped from 12v.
Lets assume you have a internally regulated alternator with the "B" lead
contactor as and wired per Bob's diagrams.
An OV happens
3-5 ms later the crowbar starts.
Lets assume that the contactor coil voltage drops to a couple of volts. This
triggers the 50 ms time to open.
The crowbar opens the CB 15 ms later.
WE still have to wait 30 ms or longer for the "B" lead contactor to open and
during this there is no OV protection and the load dump from the stored
energy is still dumping onto the bus. If there is a battery present its
likely a non event voltage wise. However if the mode of operation is
alternator only then there can be 20+ volt voltage spike on top of the 12v
nominal voltage. A mag equipped engine will press on but your avionics may
be toasted.
One can come up with many different senieros, too many to discuss fully in
my opinion.
As for the contactor needing 50 ms to open? I tested 3 different contactors
from Wicks and Allied and all took around 10 ms with no diode across the
coil and 50 ms with a diode across the coil. Not theory but tested facts
here.
Paul
----- Original Message -----
From: "Richard Garforth" <richard(at)hawk.flyer.co.uk>
Subject: AeroElectric-List: Alternator characteristics
>
>
> Just to throw in in another aspect on this topic. None of the
> correspondence I have seen lately refers to the inductive issues involved
> with shutting down an alternator. If you remove the field current (or
> reduce it to 2 volts), how long is it before the field collapses ? Could
> it be long enough to sustain output for some tens of milliseconds?
>
> Richard
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: OVP (Let's do what Rodney King suggested....) |
We are making a mountain out of a mole hill.
Every competent engineer I know has never seen the use of a crowbar to short
out a massive battery as in this case.
Regardless or whether it's 50 amps or 5000 amps who cares as is not
necessary. Harm is in the eyes of the beholder. With an engine that does not
need any electrons to run is a very different condition than an engine that
is automotive derived with computers that require solid power of at least
9.5V.
We should accept that different requirements dictate different solutions and
move on.
Those who want to continue using Bob's approach should feel free to do so.
Those who want to use a different approach where there is no hi current
pulse should do so.
Personally I feel the future of general aviation is with automotive derived
conversions where fuel consumption is significantly lower(more than 20%), HP
is higher (230 vs. 180 for example)for the same weight and lifetime is
longer( hard to really tell as few are past 2000 and it appears that is not
the limit). It's here today in experimental form and perhaps soon to be
certificated) Overhaul cost could be 1/10 that of the current 50-70 year old
designs IF the FAA could be modernized as well.
The LAST thing we need is another study. Bob and I will never agree and so
what! There are always disagreements on what is the best way to do things.
Both ways work so lets simply stop the debate. but that also takes both
sides to agree.
Paul
----- Original Message -----
From: "Eric M. Jones" <emjones(at)charter.net>
Subject: AeroElectric-List: Re: OVP (Let's do what Rodney King
suggested....)
>
>
> I've been keeping my head down in this OVP thing. But I am thoroughly on
> Paul's side technically. I quit selling crowbars on my website entirely.
>
> I can't even digest the voluminous postings back and forth, and have for
> the
> most part, held off posting on this issue. My concern is that there will
> not
> be any resolution on this issue. This may spill over into other issues.
> That's bad.
>
> Here's my suggestion---We require a small technical committee to look into
> the issue, evaluate the arguments, perhaps run tests and then publish the
> results. I recuse myself, and of course suggest excluding the major
> combatants, although they would supply technical information and provide
> the
> arguments.
>
> I nominate George Braly of GAMI to head the OVP technical committee. He
> seems to be a level head in these things. I suggest that George pick a
> half
> dozen similar level-heads and communicate off line, posting progress
> reports
> on the Aeroelectric List, then finally a complete report.
>
> Oh yes, Rodney King said, "Can't we just all get along?"
>
> Regards,
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> Phone (508) 764-2072
> Email: emjones(at)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
>
>
>
________________________________________________________________________________
| From: | "Ronald J. Parigoris" <rparigor(at)SUFFOLK.LIB.NY.US> |
| Subject: | AK-450 ELT Antenna and connection |
Reading on the install manual for AK-450 ELT, the antenna requires at least a 36
inch
ground plane.
Any ideas how I can install a ELT antenna on the inside of Europa XS Monowheel?
Second question is about the remote panel. It uses a telephone jack, that i understand
can be troublesome. Is it worth it at install time to get rid of the telephone
jack
and hardwire to remote, and install a nice removable connector at the unit?
Thx.
Sincerely
Ron Parigoris
________________________________________________________________________________
| Subject: | Re: Tap into antenna coax? |
| From: | "Matt Prather" <mprather(at)spro.net> |
That might work on some airplanes.. Chances are it won't work very well
on an RV. The gear leg is metal, and putting the VHF antenna close and
parallel to a long conductor will cause significant loss of efficiency.
Regards,
Matt-
VE N34RD, C150 N714BK
>
>
> Trying this one again ...
>
> Bob or anyone ...
> Would it work to tape a rubber ducky antenna outside a gear leg fairing
> to test out the handheld for xmit/rec? If it worked it could then go
> inside the fairing for more permanent use. Has anyone tried this?
> (RV7A) Jerry Grimmonpre
>
>
________________________________________________________________________________
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
| Subject: | Re: Alternator characteristics |
I have a question regarding:
--snip--
WE still have to wait 30 ms or longer for the "B" lead contactor to open and
during this there is no OV protection and the load dump from the stored
energy is still dumping onto the bus. If there is a battery present its
likely a non event voltage wise. However if the mode of operation is
alternator only then there can be 20+ volt voltage spike on top of the 12v
nominal voltage. A mag equipped engine will press on but your avionics may
be toasted
--snip--
I probably missed something along the way, but when would the mode of
operation be 'alternator only'? Is this to allow for a failed battery, or
some other scenario? I thought the purpose of the On-On-On switch (or
Cessna split rocker) was to preclude taking the battery off-line while the
alternator is connected.
Dennis Glaeser
________________________________________________________________________________
| From: | "John Danielson" <johnd(at)wlcwyo.com> |
| Subject: | Re: OVP (Let's do what Rodney King suggested....) |
I built an RV-6, I used Bob's approach to OVP with his crowbar, (I don't
even know what that means).
I understand the need for discussion on the list here, but I and I am
sure many others are totally confused now.
John L. Danielson
________________________________________________________________________________
| From: | "John Danielson" <johnd(at)wlcwyo.com> |
| Subject: | Tap into antenna coax? |
Has any one tried to use the leg gear on a RV at the comm. Antenna?
John L. Danielson
________________________________________________________________________________
| From: | "Bob C. " <flyboy.bob(at)gmail.com> |
| Subject: | Re: Alternator characteristics |
My Garmin 430 says it will operate from 11-33V . . . I bet it would
handle the "spike"?
I don't wan't to enter the argument or weigh in on either side . . . I
follow this list looking for ideas and solutions, not arguments!
I sense sincerity on both sides . . . but let's agree to disagree and
let the list get back to "normal" operation. Those of us wanting OVP
will have to make a choice . . . and I'm betting either choice will
provide "adequate" protection?
Thanks,
Bob Christensen
RV-8 Builder
wrote:
>
> I have a question regarding:
>
> --snip--
> WE still have to wait 30 ms or longer for the "B" lead contactor to open and
> during this there is no OV protection and the load dump from the stored
> energy is still dumping onto the bus. If there is a battery present its
> likely a non event voltage wise. However if the mode of operation is
> alternator only then there can be 20+ volt voltage spike on top of the 12v
> nominal voltage. A mag equipped engine will press on but your avionics may
> be toasted
> --snip--
>
> I probably missed something along the way, but when would the mode of
> operation be 'alternator only'? Is this to allow for a failed battery, or
> some other scenario? I thought the purpose of the On-On-On switch (or
> Cessna split rocker) was to preclude taking the battery off-line while the
> alternator is connected.
>
> Dennis Glaeser
>
>
>
________________________________________________________________________________
| Subject: | RE: 20% better efficiency ??? |
| From: | "George Braly" <gwbraly(at)gami.com> |
Paul,
You write:
>>Personally I feel the future of general aviation is with automotive derived
conversions where fuel consumption is significantly lower(more than 20%) - -<<
The Brake Specific Fuel Consumption is the universal yardstick of piston engine
efficiency.
Can you point me to any data on any spark ignition automotive engine that delivers
75% of its rated power to the propeller flange, at prop appropriate RPM's,
and has a BSFC anywhere close to the existing 0.385 lb/hr/hp that one gets from
a 300 Hp TCM engine?
I am unaware of any. Even the highly regarded Porsche Mooney (FADEC) engine had
to struggle to get down to 0.425.
Regards, George
---
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: OVP (Let's do what Rodney King suggested....) |
In a message dated 3/21/2005 2:33:03 P.M. Central Standard Time,
paulm(at)olypen.com writes:
Both ways work so lets simply stop the debate. but that also takes both
sides to agree.
Paul
Good Afternoon Paul,
I for one hope you never cease the discussion.
It is all way over my head, but I feel I do pick out a granule of education
from each and every interchange. It is an awful lot of work for you and Bob,
so I can see why both of you may want to drop the discussion, but please do
not feel that no benefit has been derived by we vast unwashed masses.
Thank you both very much for the time and thought expended.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Sanderson" <mldsub(at)earthlink.net> |
| Subject: | Re: Alternators (Dumb Question) |
Sorry for the interruption, but what is an ND alternator?
I am sure the answer is self evident but it escapes me.
Thanks
>
> I'd opt for an ND alternator modified to run external regulator
> for ANY belt driven certified alternator any day.
>
> Bob . . .
>
--
________________________________________________________________________________
| From: | N1deltawhiskey(at)aol.com |
| Subject: | Ongoing soap opera |
In a message dated 21-Mar-05 6:16:07 Pacific Standard Time,
emjones(at)charter.net writes:
Here's my suggestion---We require a small technical committee to look into
the issue, evaluate the arguments, perhaps run tests and then publish the
results. I recuse myself, and of course suggest excluding the major
combatants, although they would supply technical information and provide the
arguments.
Paul, Eric, Bob, et al,
I agree with this suggestion. I am probably like most on this list,
interested in learning practical methods of wiring my aircraft for safe and reliable
performance.
While I respect and appreciate the intellectual dialogue that has been going
on over various aspects of load dump and its associated issues, the volume of
relatively useless information and writings is becoming overwhelming.
Unfortunately, in the process of massive "delete" button pushing, I fear that I
may
be missing a tidbit of useful information; but is is no longer worth my time to
look for it - it is too rare.
I am not interested in the soap opera aspect of these communications any
longer, nor am I interested in who's ego is being challenged.
Please move this off list. When something useful comes of your discussions,
then share it with us. It will be readily received and appreciated.
Respectfully, Doug Windhorn
________________________________________________________________________________
| Subject: | Re: AK-450 ELT Antenna and connection |
| From: | James H Nelson <rv9jim(at)juno.com> |
Ron,
I installed mine just behind the baggage comp hatch and ran 6
spaced copper tapes glassed to the bottom. I mounted the antenna on a
piece of aluminum where I attached the copper radials to form the ground
plane. It's really not needed. think about the portability issue and
there is no ground plane there. Also, portable com units (like my Icom
unit) which works fine with out a ground plane. Figured that out to
late.
Jim (Mono-Wheel sold)
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Alternators (Dumb Question) |
Sanderson wrote:
>
>Sorry for the interruption, but what is an ND alternator?
>I am sure the answer is self evident but it escapes me.
>Thanks
>
Nippon Denso brand of Japanese auto electric stuff
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
| Subject: | Re: Alternator characteristics |
Paul Messinger wrote:
> And finally the Eric Jones and recommended by me
> approach where the OV is instantly clamped to a safe level and then the
> alternator is taken off line and there is no chance of any post CB popping
> load dump residual voltage to deal with as the circuit is clamped before
> during and after.
How is the OV clamped? The only ways I can think of to control the
voltage are to divert the current like the crowbar does, or to have a
regulator-like device that the alternator output goes through.
The second option would raise reliability questions for me. Having seen
common problems with regulators in the motorcycle world, I have formed
the opinion that it is not easy to build a device that can carry the
constant output of an alternator and cope with real world problems like
poor connections and inadequate cooling.
--
Andrew Rowley
arowley(at)ncable.net.au
________________________________________________________________________________
| From: | Steve Thomas <lists(at)stevet.net> |
| Subject: | Re: Ongoing soap opera |
Hello N1deltawhiskey,
Monday, March 21, 2005, 1:42:45 PM, you wrote:
Nac> Please move this off list. When something useful comes of your discussions,
Nac> then share it with us. It will be readily received and appreciated.
I couldn't disagree more. This discussion is the best thing I've seen
on any list anywhere. I'm no more of an expert than the least of you
out there, but I have learned more about alternators than I've ever
dreamed about knowing despite the fact that I don't understand a lot
of it.
I'm sad that some of the participants are taking this disagreement so
personally. I do not see that anything has been said here that needs
to be taken personally. It's just an argument about design and
testing.
I'd like the discussion to continue. Paul's recent comment about
using different techniques for different applications is good advice.
But, why stop the on-line discussion? I like it when someone can lay
out a clear argument based on what facts they think they have. Why
squash that? And, to presume that someone is right because of who they
are (or claim to be) makes no sense to me at all.
If you don't like the discussion, as has been said, delete it. You
can tell in the first paragraph whether it is of interest or not. As
for me, I'd like to continue to read.
--
Best regards,
Steve mailto:lists(at)stevet.net.nospam
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: Alternators (Dumb Question) |
Nippon Denso automotive alternator
Sanderson wrote:
>
>Sorry for the interruption, but what is an ND alternator?
>I am sure the answer is self evident but it escapes me.
>Thanks
>
>
>
>> I'd opt for an ND alternator modified to run external regulator
>> for ANY belt driven certified alternator any day.
>>
>> Bob . . .
>>
>>
>>
>
>
>
________________________________________________________________________________
| From: | Andrew Rowley <arowley(at)ncable.net.au> |
Paul Messinger wrote:
> I only wanted to define what was inside
> the realistic range to show how ridiculous the crowbar approach was
That doesn't sound like a good point to begin an objective experiment.
> Bob then goes on with "out of the thin air conclusions" :-) that are not
> based on any real facts and in fact the available data (again from various
> data sheets) do not support the conclusions.
>
> For example:
>
> From the report:
>
> ". Battery delta E for 135A load is about 2.4 volts for an internal
> impedance of about 17 milliohms.
>
> About what one would expect from a two year old battery that started out in
> the 8 to 10 milliohm."
>
>
> The Panasonic data sheet says approximately 12 milliohm. Approximately is
> hardly an engineering term but it's also not 8-10 as Bob suggests for a new
> battery.
These figures sound close enough to the data sheet to be usable to me. I
don't see how the difference affects the conclusion. You used 2
batteries for 3.5 milliohms resistance, which is even less than the 8-10
that you are objecting to.
> Going on we find a violation of ohms law :-)
>
> When I do the math I get 70 NOT 7 milliohms on the last line (for the CB)
> which conflicts with the first line of 62 milliohms total loop resistance.
> From this and my earlier comments the entire technical analysis is clearly
> faulty.
I don't see that it conflicts. It is the maximum from the
specifications. There is no reason it can't be lower. I don't see that
the conclusions are affected. As far as I can see it only affects the
calculation of the average joint resistance. It seems like a nitpick,
rather than something that puts the entire technical analysis into doubt.
> I simply do not understand the massive resistance to make an improvement
> (even the addition of 1/4 ohm is resisted).
I think that one of the objectives of the OVP short is to control the
voltage until the alternator shuts down. To do that you probably need to
be able to take the entire output of the alternator. If you put a
resistor there, you need to make sure it is sized according to the
alternator output. You would also need to subtract the resistance of the
rest of the circuit from the resistor value. At this point, it is
probably getting unnecessarily complex.
--
Andrew Rowley
arowley(at)ncable.net.au
________________________________________________________________________________
| From: | Jerzy Krasinski <krasinski(at)provalue.net> |
| Subject: | Re: Ongoing soap opera |
I would like the discussion to continue.
However, the discussion would not be harmed at all if it was done in a
cool professional atmosphere. In fact it would help a lot.
Lets attack the issue, not the people.
Jerzy
________________________________________________________________________________
| From: | "Bob McDevitt" <mcdevitt(at)sympatico.ca> |
I am having a problem that has me stumped. The problem occurs with the
engine running or off. As I am doing all my trouble shooting with the engine
off, I will use that mode for all descriptions.
Master on, radio on, the bus voltage reads 12.5 volts, when the PTT switch
is pressed, the voltage rises to 13.5 volts.
I have replaced all suspect cables (battery + and -) starter cable as well
as the master and starter relays. Problem still exists.
I have disconnected the alternator B lead to no avail. Can anyone offer a
suggestion for a cure?
Bob McDevitt
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Extra Voltage! |
>
>
>I am having a problem that has me stumped. The problem occurs with the
>engine running or off. As I am doing all my trouble shooting with the engine
>off, I will use that mode for all descriptions.
>Master on, radio on, the bus voltage reads 12.5 volts, when the PTT switch
>is pressed, the voltage rises to 13.5 volts.
>I have replaced all suspect cables (battery + and -) starter cable as well
>as the master and starter relays. Problem still exists.
>I have disconnected the alternator B lead to no avail. Can anyone offer a
>suggestion for a cure?
>
>Bob McDevitt
Your voltmeter appears to suffer from RF interference.
Just as a quick test, can you dummy load the transceiver
and see if the problem goes away?
See
http://www.aeroelectric.com/Pictures/DummyLoad.jpg
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Ongoing soap opera |
>
>In a message dated 21-Mar-05 6:16:07 Pacific Standard Time,
>emjones(at)charter.net writes:
>Here's my suggestion---We require a small technical committee to look into
>the issue, evaluate the arguments, perhaps run tests and then publish the
>results.
. . . and who shall we delegate the responsibility of requiring anything?
> I recuse myself, and of course suggest excluding the major
>combatants, although they would supply technical information and provide the
>arguments.
. . . and who should be included/excluded from the 'technical committee'?
What makes you think anyone is fighting? Listen (read) carefully and
see who's words are most likely to provoke combative responses and then
deduce how the target reacts to those words.
>Paul, Eric, Bob, et al,
>
>I agree with this suggestion. I am probably like most on this list,
>interested in learning practical methods of wiring my aircraft for safe
>and reliable
>performance.
>
>While I respect and appreciate the intellectual dialogue that has been going
>on over various aspects of load dump and its associated issues, the volume of
>relatively useless information and writings is becoming overwhelming.
>Unfortunately, in the process of massive "delete" button pushing, I fear
>that I may
>be missing a tidbit of useful information; but is is no longer worth my
>time to
>look for it - it is too rare.
When we walk into a library, there will no doubt be countless
texts that contain equally countless tidbits of useful information
which will never come to our attention. One is ALWAYS at risk
of missing the golden needles in the storm of chaff that surrounds
us daily in every aspect of life.
Please rest assured that (1) there are no battles being waged here
and no egos to be stroked - at least not from my perspective. (2)
when the simple-ideas are all sorted and fitted to their respective
places in our toolboxes, I will craft a consensus document that will
will satisfy the professional requirements of any person who wishes
to co-author the text or at least sprinkle with holy water.
>I am not interested in the soap opera aspect of these communications any
>longer, nor am I interested in who's ego is being challenged.
>
>Please move this off list. When something useful comes of your discussions,
>then share it with us. It will be readily received and appreciated.
Forgive me sir but I'm not about to challenge anyone to censure
what they write other than to ask for explanations in terms of
simple ideas that you or anyone else can understand and use. I
hope that nobody else would either. I'm sorry you believe this
activity to be "soap opera" . . . please use your delete key
and be assured that the document you seek will come to pass. In
the mean time, I think it's counter productive to push the
conversation into hiding when so many people have expressed an
interest in listening in.
Bob . . .
________________________________________________________________________________
| From: | Richard Riley <Richard(at)RILEY.NET> |
| Subject: | Re: Ongoing soap opera |
At 02:28 PM 3/21/05, Steve Thomas wrote:
>
>Hello N1deltawhiskey,
>
>Monday, March 21, 2005, 1:42:45 PM, you wrote:
>
>Nac> Please move this off list. When something useful comes of your
>discussions,
>Nac> then share it with us. It will be readily received and appreciated.
>
>I couldn't disagree more. This discussion is the best thing I've seen
>on any list anywhere. I'm no more of an expert than the least of you
>out there, but I have learned more about alternators than I've ever
>dreamed about knowing despite the fact that I don't understand a lot
>of it.
I'm hoping that at the end, someone will translate all the information into
knowledge that I can use. As it is, as near as I can tell from reading
both sides, any voltage regulator, any over voltage protection and any
alternator will certainly kill me.
________________________________________________________________________________
| From: | N1deltawhiskey(at)aol.com |
| Subject: | Re: Ongoing soap opera |
In a message dated 21-Mar-05 17:03:05 Pacific Standard Time,
krasinski(at)provalue.net writes:
Lets attack the issue, not the people.
I hope there is no perception that I was attacking anyone with my post; it
was certainly not my intent. All of the major participants have a lot to offer
and I would certainly not want to put a damper on whatever substantial
contributions they can make to better understanding their airplane's electrical
systems.
My response was to a suggestion by one of the primary participants that some
of the dialogue might best be moved off the list, and given MY priorities, I
can agree with that position. At least keeping the discussion "on point" if it
is to continue would be of more benefit to me. I understand that not all will
agree with this view and take no offense at that. It is, indeed, the issue
that matters.
Opinions (of which there are many) do not need to be rebutted - they are
simply that, the writer's opinion, regardless of its alleged factual basis.
Facts, or alleged facts, may be challengeable. If the dialogue was trimmed to
the
facts, the information would be of much more use IMHO.
One thing needs to be kept in mind -- a better mousetrap is not better unless
it can be practically utilized. As an example, I would like a dual Chelton
glass screen system in my cockpit and consider that "better" (at least
functionally) than my Dynon. But, it is not practical for me and hence, of little
use
when the Dynon will do what I want it to do. It doesn't matter what one
considers, there is always a "better" idea, product, system, etc. out there;
somewhere.
If a crowbar circuit will work for me, without giving me tripping problems
and damaging my equipment, I will deem it functional and practical. In that
case, the better mousetrap is only better if it costs no more, or even better,
less. On the other hand, if it does not do what I expect it to do, I will be
looking for that better OVP, even at a higher cost. Just some food for thought.
With regards, and again respectfully, Doug
________________________________________________________________________________
| From: | "Ed Anderson" <eanderson(at)carolina.rr.com> |
| Subject: | Re: Ongoing soap opera |
.
>
> I'm hoping that at the end, someone will translate all the information
into
> knowledge that I can use. As it is, as near as I can tell from reading
> both sides, any voltage regulator, any over voltage protection and any
> alternator will certainly kill me.
>
Could happen I suppose, but on the other hand I think there are other things
much more likely to do it {:>).
I would like to know what is the statistical likelihood of any of these
things happening? I have driven automobiles since the early 50's and have
had one alternator fail - it simply stopped producing voltage, well it
actually would produce 2.1 volts (bad diodes), but not enough. The battery
idiot light came on while driving and I immediately head for home on the
battery. Turning on the turn signal to turn into my drive way killed the
engine. But, I knew what had happened and made a bee-line for home before
the juice ran out.
Never had and have never hear of an auto alternator failing and killing the
cars electronics through over-voltage - although I have no doubt it could
and has happened. But, it must be a fairly rare occurrence given the
millions and millions of autos on the road.
I have now been flying an all electric (rotary) aircraft since 1997 and have
shed one of the two batteries I started out with (changing it each year -
but now considering going to every two years using a battery pulser to
reduce the sulfating?
But, my point is - how often does this happen in real life?? And are there
other things statistically more likely to kill me (I would imagine just
about everything else in fact - alternators are probably far, far down the
list {:>)).
Just a personal opinion of course.
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com
________________________________________________________________________________
| From: | "Giffen A Marr" <gamarr(at)charter.net> |
Suggestion
Why not set up a meeting between the individuals and review the data.
Obviously, there is concern about clamping the OV during the shutdown of the
alternator. Is it significant? Is there a safety of flight issue for the all
electronic aircraft? Does it put at risk the $$$ avionics and/or engine
electronics? Review the test data that has raised the concern, reach a
consensus, and let the rest of us know. Trying to review data on the list is
not a practical way to resolve this concern because of the complexity of the
issue.
Giff Marr
LIVP/20B 30%
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Re: Alternator characteristics |
<>
<>
I'm afraid my question might get lost in the sea of comments on this
subject, but here goes: Given the data above, I calculate that a "runaway"
60-amp alternator can only raise the voltage of the battery about 0.7 volts
from it's static condition. Let's say it takes 13.5 or so for it to accept
any current, then an alternator failure should raise the voltage to only
14.2. I just don't understand the paranoia about over-voltage conditions,
as with a battery in the circuit I don't know where they come from.
Certainly an alternator cannot be allowed to run forever under that
condition, but it seems to me that if the pilot were alerted to an
over-voltage condition he would have all the time in the world to reach over
and pull the alternator CB, whether it be for the field in the case of an
externally-regulated alternator or the output breaker for an
internally-regulated alternator. That gives the pilot the option of turning
the alternator back on if the battery starts to droop, not possible with an
automatic OV "protection" system. And I guess I'll have to side against
using a device that intentionally puts in an overload as a "protection"
device. No?
(My original plan was to use an internally-regulated alternator feeding into
a 60-amp CB and that's all. No automatic OV protection - but then I let
myself get swayed by arguments on the list and went the other way.)
Gary Casey
________________________________________________________________________________
| From: | "Jerry Isler" <jlisler(at)alltel.net> |
| Subject: | Re: Points for discussion OVP//more |
As a lowly RV owner with a Vans 35 amp alternator, solid state external
voltage regulator (VR-166?) and an AeroElectric crowbar overvoltage
protection device wired in accordance with Bob's recommendation, what does
all of this mean to me? If I experience an overvoltage condition and the
crowbar OVP device trips the field breaker, are you saying the system is
going to experience hundreds of excess amps from my 35 amp alternator for an
fraction of a second and melt my lovely RV (and me) into oblivion? Obviously
if there is an overvoltage condition on the system there is already a
failure of some sort. Are you saying the crowbar OVP will make the failure
worse?
Jerry Isler
RV4 N455J
----- Original Message -----
From: "Paul Messinger" <paulm(at)olypen.com>
Subject: Re: AeroElectric-List: Points for discussion OVP//more
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
> To:
> Subject: Re: AeroElectric-List: Points for discussion OVP//more
>
>
> >
> >
> >
> >>
>
> . . . but assuming your system
> > IS capable of producing a 250A trip current, is there
> > any analysis to support the notion that this is "bad"
> > for other systems in the aircraft?
> >
> > Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator characteristics |
>
><voltage until the alternator shuts down.>>
><>
>
>I'm afraid my question might get lost in the sea of comments on this
>subject, but here goes: Given the data above, I calculate that a "runaway"
>60-amp alternator can only raise the voltage of the battery about 0.7 volts
>from it's static condition.
I think you're assuming that the load impedance of a batttery
to charging currents is the same as source impedance for
delivery of energy.
See Rev B to the White Paper at:
http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_B.pdf
> Let's say it takes 13.5 or so for it to accept
>any current, then an alternator failure should raise the voltage to only
>14.2. I just don't understand the paranoia about over-voltage conditions,
>as with a battery in the circuit I don't know where they come from.
>Certainly an alternator cannot be allowed to run forever under that
>condition, but it seems to me that if the pilot were alerted to an
>over-voltage condition he would have all the time in the world to reach over
>and pull the alternator CB, whether it be for the field in the case of an
>externally-regulated alternator or the output breaker for an
>internally-regulated alternator. That gives the pilot the option of turning
>the alternator back on if the battery starts to droop, not possible with an
>automatic OV "protection" system. And I guess I'll have to side against
>using a device that intentionally puts in an overload as a "protection"
>device. No?
Close . . . In the white paper I do raise the question
as to the validity of ov protection on small alternators
ASSUMING that a good battery is in place to mitigate the
over-charging condition.
>(My original plan was to use an internally-regulated alternator feeding into
>a 60-amp CB and that's all. No automatic OV protection - but then I let
>myself get swayed by arguments on the list and went the other way.)
Which arguments? I don't recall any statements wherein the EFFECTS
of a runaway alternator were anything to brush aside. There have
been discussions about PROBABILITY of a runaway condition where
I believe the consensus is that OV in a modern alternator is
a very low probability . . . but I don't believe anyone has
suggested that it's ZERO.
So, here are the choices. Internal or external regulated
alternator. Depending on which technology is selected, applying
OV protection must take different routes because of lack
of access to the field circuit of an internally regulated
alternator.
Internally regulated alternators can be easily shut down
with no fanfare, no smoke, no stresses on components created
or exacerbated by the presence of an OV protection system.
However, there is risk to SOME internally regulated machines
when the b-lead is opened while the alternator is working
hard. We don't have definitive numbers on this risk because
we have zero knowledge of the alternators that have
suffered damage.
Should we leave OV protection off to save an alternator
that's capable of frying the rest of the system? The all
inclusive solution is to apply what techniques we know are
friendly to the task of saving an already failed alternator
(or tolerating operator induced stresses when the system
is switched on/off while loaded and at high RPM).
Now, we can discuss different ways to open the b-lead
contactor and various band-aids to stack on top of that
to accommodate the switch-flipper but once the major risk
has been caged, the rest requires assessment of the cost/
complexity/benefits ratios.
The simplest approach is to protect the airplane first
and understand the risks of random switch-flipping such
that risks to the alternator are eliminated.
Bob . . .
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
You need to read Bobs white paper and consider your comments again as you
have confused something. Or I have not made myself clear enough.
When Bob says its 7 and the simple math using his numbers comes out 70 its
a simple math error but that affects his assumptions in other math.
One NEVER uses assumptions and Always uses spec values and worst case design
to be sure the design will always meet the design intent with ANY
conbination of parts. The subject test simply does not do this.
The design also overstresses parts under worst case design rules.
Paul
----- Original Message -----
From: "Andrew Rowley" <arowley(at)ncable.net.au>
Subject: AeroElectric-List: Re:
>
>
> Paul Messinger wrote:
>
>>
>
>> I only wanted to define what was inside
>> the realistic range to show how ridiculous the crowbar approach was
>
> That doesn't sound like a good point to begin an objective experiment.
>
>
>> Bob then goes on with "out of the thin air conclusions" :-) that are not
>> based on any real facts and in fact the available data (again from
>> various
>> data sheets) do not support the conclusions.
>>
>> For example:
>>
>> From the report:
>>
>> ". Battery delta E for 135A load is about 2.4 volts for an internal
>> impedance of about 17 milliohms.
>>
>> About what one would expect from a two year old battery that started out
>> in
>> the 8 to 10 milliohm."
>>
>>
>> The Panasonic data sheet says approximately 12 milliohm. Approximately is
>> hardly an engineering term but it's also not 8-10 as Bob suggests for a
>> new
>> battery.
>
> These figures sound close enough to the data sheet to be usable to me. I
> don't see how the difference affects the conclusion. You used 2
> batteries for 3.5 milliohms resistance, which is even less than the 8-10
> that you are objecting to.
>
>
>> Going on we find a violation of ohms law :-)
>>
>> When I do the math I get 70 NOT 7 milliohms on the last line (for the CB)
>> which conflicts with the first line of 62 milliohms total loop
>> resistance.
>> From this and my earlier comments the entire technical analysis is
>> clearly
>> faulty.
>
> I don't see that it conflicts. It is the maximum from the
> specifications. There is no reason it can't be lower. I don't see that
> the conclusions are affected. As far as I can see it only affects the
> calculation of the average joint resistance. It seems like a nitpick,
> rather than something that puts the entire technical analysis into doubt.
>
>> I simply do not understand the massive resistance to make an improvement
>> (even the addition of 1/4 ohm is resisted).
>
> I think that one of the objectives of the OVP short is to control the
> voltage until the alternator shuts down. To do that you probably need to
> be able to take the entire output of the alternator. If you put a
> resistor there, you need to make sure it is sized according to the
> alternator output. You would also need to subtract the resistance of the
> rest of the circuit from the resistor value. At this point, it is
> probably getting unnecessarily complex.
>
>
> --
> Andrew Rowley
> arowley(at)ncable.net.au
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator characteristics |
I have tested a battery with a constant current 40 amp supply. The battery
was a concord 25ah aircraft battery.
A battery that is fully charged acts more like a capacitor than a sink for
excess current. The test battery terminal voltage was well above 20V in
under 30 seconds and going up fast.
I have concluded (and the experts agree) that a battery will not clamp the
voltage if there is a lot of current that the battery does not need for
charging, it just goes into overcharge mode and away we go :-)
A battery is great as a capacitor for load dumps and other short term
overcurrents from the alternator but useless in the case of a long term
failure like a failed hi regulator, Thus the need for some sort of OVP.
You can consider the OVP as a voltage clamp while opening the CB that kills
the field and or opens the "B" lead.
The subject failure is quite rare.
Paul
----- Original Message -----
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: Re: AeroElectric-List: Alternator characteristics
>
>
> < voltage until the alternator shuts down.>>
> <>
>
> I'm afraid my question might get lost in the sea of comments on this
> subject, but here goes: Given the data above, I calculate that a
> "runaway"
> 60-amp alternator can only raise the voltage of the battery about 0.7
> volts
> from it's static condition. Let's say it takes 13.5 or so for it to
> accept
> any current, then an alternator failure should raise the voltage to only
> 14.2. I just don't understand the paranoia about over-voltage conditions,
> as with a battery in the circuit I don't know where they come from.
> Certainly an alternator cannot be allowed to run forever under that
> condition, but it seems to me that if the pilot were alerted to an
> over-voltage condition he would have all the time in the world to reach
> over
> and pull the alternator CB, whether it be for the field in the case of an
> externally-regulated alternator or the output breaker for an
> internally-regulated alternator. That gives the pilot the option of
> turning
> the alternator back on if the battery starts to droop, not possible with
> an
> automatic OV "protection" system. And I guess I'll have to side against
> using a device that intentionally puts in an overload as a "protection"
> device. No?
>
> (My original plan was to use an internally-regulated alternator feeding
> into
> a 60-amp CB and that's all. No automatic OV protection - but then I let
> myself get swayed by arguments on the list and went the other way.)
>
> Gary Casey
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Ongoing soap opera |
>
>
>I'm hoping that at the end, someone will translate all the information into
>knowledge that I can use. As it is, as near as I can tell from reading
>both sides, any voltage regulator, any over voltage protection and any
>alternator will certainly kill me.
I will do that document . . . as I mentioned earlier.
I don't think anyone died JUST because their system went into
OV and toasted things. As I've mentioned many times, when I
walk up to a rental airplane, I have ZERO knowledge of that
electrical system's history. I plan to reach airport of intended
destination with NOTHING working on the panel. Whether the
panel goes black because of an ov condition, alternator craps
and battery is soggy, wires come loose . . . it doesn't matter.
The way I fly and the stuff I carry in my flight bag makes
for a high order probability of comfortably terminating the
flight.
However, people have died when a system went down, descents
had to be made through ice, windshields became non-transparent
and the pilot lost directional control on a snow covered runway
while trying to land looking out the foul weather window.
It's a classic example of how several things stack on top
of each other to influence the outcome of the experience.
This guy made a successful descent through hell-on-wings,
set up an approach, got the wheels on the runway of an
airport and died anyhow. Was it the OV condition that
killed him?
Take care lest we build emotions into your perceptions
of this discussion that are not warranted and certainly
don't advance the science. I know that's difficult because
of how our culture treats almost all discussions. Watch
the Sunday morning talking-head shows and the last thing
you find is a quest for logical stacking of simple-ideas
toward an elegant solution. EVERY discussion is a contest
with every participant wanting to feel like he/she
was the "winner".
It's difficult to watch an energetic discussion without
transferring one's own perceptions of emotional investments
into what we're watching. Try to ignore who is talking . . .
it's irrelevant. Look for the simple-ideas and science
that become the building blocks for later solutions.
When simple ideas come to light, they are inarguable
and invariable. If you're not interested in those things, that's
perfectly okay too. Hit the delete key and wait for the
consensus paper. You're not required to participate or
even observe what's going on any more than you're required
to read every book in a library. When the book of simple-
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Ongoing soap opera |
>
>In a message dated 21-Mar-05 17:03:05 Pacific Standard Time,
>krasinski(at)provalue.net writes:
>Lets attack the issue, not the people.
>
>I hope there is no perception that I was attacking anyone with my post; it
>was certainly not my intent.
I didn't think you were. I did think you were frustrated with
what you may perceive as a lot of energetic blowing of the chaff . . .
>My response was to a suggestion by one of the primary participants that some
>of the dialogue might best be moved off the list, and given MY priorities, I
>can agree with that position. At least keeping the discussion "on point"
>if it
>is to continue would be of more benefit to me. I understand that not all will
>agree with this view and take no offense at that. It is, indeed, the issue
>that matters.
I think my analogy of the library is a good one here. Would you
really want anyone (or any committee) to filter or limit what
is placed on library shelves? I know it happens all the time and
one special-interest group or another can probably take some satisfaction
in that fact. I sincerely hope that this List represent a library
of all the things participants can bring to it. Your computer is
your library card and your delete key is the method by which you
select what is interesting/useful to read.
>Opinions (of which there are many) do not need to be rebutted - they are
>simply that, the writer's opinion, regardless of its alleged factual basis.
>Facts, or alleged facts, may be challengeable. If the dialogue was
>trimmed to the
>facts, the information would be of much more use IMHO.
I'm hoping to drive to the level of simple-ideas. These are not
opinions. They are invariable and inarguable. Once a useful array
of ideas is identified, one can begin to assemble useful systems.
Here is where the crown of elegance can take on many forms and
end users can select from which ever piece of jewelry suits
their fancy. But EVERY system's design and performance should
be explained and understood at the level of simple-ideas . . .
to do less reduces the marketing or promotion of that design
to the same level as that of a product in a television infomercial.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator characteristics |
>
>I have tested a battery with a constant current 40 amp supply. The battery
>was a concord 25ah aircraft battery.
>
>A battery that is fully charged acts more like a capacitor than a sink for
>excess current. The test battery terminal voltage was well above 20V in
>under 30 seconds and going up fast.
>
>I have concluded (and the experts agree) that a battery will not clamp the
>voltage if there is a lot of current that the battery does not need for
>charging, it just goes into overcharge mode and away we go :-)
>
>A battery is great as a capacitor for load dumps and other short term
>overcurrents from the alternator but useless in the case of a long term
>failure like a failed hi regulator, Thus the need for some sort of OVP.
>
>You can consider the OVP as a voltage clamp while opening the CB that kills
>the field and or opens the "B" lead.
>
>The subject failure is quite rare.
Agreed. Revision B to the White Paper discusses the battery's role
in OV dynamics. There are two or perhaps three phases to the
rise in voltage across an overcharged battery. The first is fairly
fast and operates in accordance with a shift in the battery's
chemistry to morph from energy supplier to energy absorber. There's
a transition area I've described as a "knee" in the curve before the
batter goes into the grunt mode of sopping up all the energy it can.
The third phase is a function of the battery's "load" impedance on
the overcharge source. Note that this impedance is decidedly larger
than when the battery is a source of energy.
Time from onset of OV condition to the end of the "knee" is a few
hundred milliseconds max . . . PLENTY of time for any ov detection
and mitigation system to rope the alternator and bring it to the
ground. The max voltage to be expected based on relatively hefty
alternators and batteries at or near end of life is 20 volts. This
is where the 20v for one second requirement in DO-160 came from.
It's true that an unabated OV event can carry the system to
spectacular and potentially smelly heights. But it takes a lot
of time compared to the window in which we EXPECT an ov protection
system to do its job.
Bob . . .
________________________________________________________________________________
| From: | rd2(at)evenlink.com |
Bob et all,
Is there a way to modify an AP with alt-hold to select certain alt, to
select vert speed, and to be able to follow a GS? Is there a site that
explains how the altitude part works?
Thanks
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: AeroElectric-List Digest: 33 Msgs - 03/21/05 |
I agree with Steve Thomas. The discussion (argument?) is healthy and
informative. I learn more every day and enjoy reading (if not understanding) all
comments on this list.
Stan Sutterfield
Tampa
www.rv-8a.net
Nac> Please move this off list. When something useful comes of your
discussions,
Nac> then share it with us. It will be readily received and appreciated.
I couldn't disagree more. This discussion is the best thing I've seen
on any list anywhere. I'm no more of an expert than the least of you
out there, but I have learned more about alternators than I've ever
dreamed about knowing despite the fact that I don't understand a lot
of it....
I'd like the discussion to continue....
If you don't like the discussion, as has been said, delete it. You
can tell in the first paragraph whether it is of interest or not. As
for me, I'd like to continue to read.
________________________________________________________________________________
| From: | "Stein Bruch" <stein(at)steinair.com> |
That functionality isn't easily "modified" into existance, as you're talking
about several different things that aren't related.
The Alt Hold & V.Speed are relatively easy, and both TruTrak as well as Trio
are offering a "Altitude Hold" with Vertical Speed.
The GS part is much more complex, because now you're following a NAV signal,
not a GPS or simple referential air data.
I think the easiest way to accomplish what you want is to simply buy an
exisiting autopilot with that functionality!
Just my 2 cents.
Cheers,
Stein.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
rd2(at)evenlink.com
Subject: AeroElectric-List: Auto Pilot
Bob et all,
Is there a way to modify an AP with alt-hold to select certain alt, to
select vert speed, and to be able to follow a GS? Is there a site that
explains how the altitude part works?
Thanks
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: RE: 20% better efficiency ??? |
I was referencing specifically to the old 0-360 lyc.
The numbers you state are very good and may be better then ours.
As for fuel flow there is good data but no current data as the dyno fuel
flow card is in for repair and has been for some time.
The engine of interest is a very modern modified auto engine with auto type
fuel and spark computer control systems. I had expected better / more
current by now data but the dyno card has been a hold up.
The data I used was from a side by side flyoff between an earlier version of
the engine vs. the 0-360 in identical aircraft where the aircraft were flown
the same time and after landing the amount of fuel expended was measured.
Both aircraft had on board fuel flow measuring systems.
Both had similar fuel flow at 100% of power but at 75% the auto conversion
was 20+% lower fuel flow. Airspeeds were matched for this test.
The Lyc was the 180 HP version and the auto conversion was at the time 200
HP. Its now 230 HP (231.5 +/- as measured) on the certified dyno best
engine case.. Gear reduction to prop speeds IE 2700 max prop rpm.
On the other hand its low noise and the very low vibration, partly due to
the hither frequencies of the higher rpms due to the geat reduction. Runs on
any grade of auto gas or 100LL.
Paul
----- Original Message -----
From: "George Braly" <gwbraly(at)gami.com>
Subject: AeroElectric-List: RE: 20% better efficiency ???
>
>
> Paul,
>
> You write:
>
>>>Personally I feel the future of general aviation is with automotive
>>>derived
> conversions where fuel consumption is significantly lower(more than
> 20%) - -<<
>
> The Brake Specific Fuel Consumption is the universal yardstick of piston
> engine efficiency.
>
> Can you point me to any data on any spark ignition automotive engine that
> delivers 75% of its rated power to the propeller flange, at prop
> appropriate RPM's, and has a BSFC anywhere close to the existing 0.385
> lb/hr/hp that one gets from a 300 Hp TCM engine?
>
>
> I am unaware of any. Even the highly regarded Porsche Mooney (FADEC)
> engine had to struggle to get down to 0.425.
>
>
> Regards, George
>
>
> ---
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Diodes across relay coils |
For decades 99.999% of the engineering world recommended and used the common
rectifier diode across inductors like relay coils to suppress the inductive
spike that happens when the power to the inductor is interrupted.
Many (including Bob) have stated that while this practice extends the start
of opening time of the relay it does not change the opening speed once the
relay contacts start opening. Thus the only down side to use of the diode is
a delay in the start of opening. Normally this is not important.
For example the common contactor used for starting or battery connection
will open in 10 ms with no diode and it takes 50 ms with a diode.
A friend sent me several links including one at Potter and Brumfield (a
major relay manufacturer) that not only had a comparison table (of
suppression devices) but a comment on what the use of a diode really does.
I have extracted part of that comment below and also included at the end of
this post the links for the interested.
""Effects of Coil Suppression on Relay Dynamics and Life
Even though the use of coil suppression is becoming more significant,
relays are normally designed without taking the dynamic impact of
suppressors into account. The optimum switching life (for normally-open
contacts) is therefore obtained with a totally unsuppressed relay and
statements of rated electrical life are usually based on this premise. The
successful "breaking" of a DC load requires that the relay contacts move
to open with a reasonably high speed.
A typical relay will have an accelerating motion of its armature toward the
unenergized rest position during drop-out. The velocity of the armature at
the instant of contact opening will play a significant role in the relay's
ability to avoid "tack welding" by providing adequate force to break any
light welds made during the "make" of a high current resistive load (or one
with a high in-rush current). It is the velocity of the armature that is
most
affected by coil suppression. If the suppressor provides a conducting path,
thus allowing the stored energy in the relay's magnetic circuit to decay
slowly, the armature motion will be retarded and the armature may even
temporarily reverse direction. The reversing of direction and re-closing of
the contacts (particularly when combined with inductive loads) often leads
to random, intermittent "tack welding" of the contacts such that the relay
may free itself if operated again or even jarred slightly.
Based upon the impact on armature motion and optimizing for normallyopen
contacts, the best suppression method is to use a silicon transient
suppressor diode. This suppressor will have the least effect on relay
dropout
dynamics since the relay transient will be allowed to go to a
predetermined voltage level and then permit current to flow with a low
impedance. This results in the stored energy being quickly dissipated by
the suppressor. Transient suppressor diodes are available as bi-directional
components and permit the relay to be non-polarized when installed
internally. Note that if a uni-directional transient suppressor is used, a
rectifier diode must be placed in series with it to block normal current
flow and it has little advantage over the use of a zener diode. ""
This and a table comparing different types of suppressors (see the below
links) clearly indicates a couple of things.
First 99.99% of engineers have been using the wrong type of suppressor for
many years.
The simple diode is perhaps the worst choice(see the table of comparisons at
the links). In the case of power contactors the use of a simple diode
actually slow the mechanical opening of the contacts quite a lot and
increases the likely hood of contact welding.
I have tested this last year in the load dump testing and recorded large
multiple contact bouncing.
I have removed all the simple diodes across relays and replaced them with by
directional transorbs and also supplied parts to the local builders as well.
Here are a couple of links, There is also one in Europe that I cannot find
right now with the same conclusions.
http://relays.tycoelectronics.com/application.asp
http://relays.tycoelectronics.com/kilovac/appnotes/transients.stm
Paul
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator characteristics |
The alternator is clamped with transorbs and the OVP takes over if the OV is
for longer than 200 ms in our design and a few ms in Bob's design. The
reason for the difference in timing is due to different approaches to the
same fundamental concerns. Two of several good ways to mitigate the
concerns. Lots of bad ways and usually more than one good way to solve most
any concern.
In the case of a "B" lead contactor there is the possibility it will not
open until some time after the CB is opened (It is slow in my testing) and
in that case the transorbs again act to clamp the OV.
Paul
----- Original Message -----
From: "Andrew Rowley" <arowley(at)ncable.net.au>
Subject: Re: AeroElectric-List: Alternator characteristics
>
>
> Paul Messinger wrote:
>> And finally the Eric Jones and recommended by me
>> approach where the OV is instantly clamped to a safe level and then the
>> alternator is taken off line and there is no chance of any post CB
>> popping
>> load dump residual voltage to deal with as the circuit is clamped before
>> during and after.
>
> How is the OV clamped? The only ways I can think of to control the
> voltage are to divert the current like the crowbar does, or to have a
> regulator-like device that the alternator output goes through.
>
> The second option would raise reliability questions for me. Having seen
> common problems with regulators in the motorcycle world, I have formed
> the opinion that it is not easy to build a device that can carry the
> constant output of an alternator and cope with real world problems like
> poor connections and inadequate cooling.
>
> --
> Andrew Rowley
> arowley(at)ncable.net.au
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator characteristics |
One emergency mode of operation considered for an electrically dependent
engine is the case where the battery(s) are off line for what ever reason
including open cell or contactor failure.
With no battery a large load dump; turning off the hyd pump, or landing gear
electric motor can cause the bus voltage to go to 30-50 volts depending on
what load is already on the bus and how big the current being turned off is.
The battery will absorb most any size load dump if its on line. Using a
25,000 mfd capacitor has been suggedted in the "no battery mode" but even
that sized capacitor may not keep the bus voltage under 20 v and if there is
a OVP set at 16.2 V (as recommended) its very likely that will trip. Once
off line, most alternators will not restart without a battery for the
initial voltage/current required.
Lots of different things to consider and often a different solution is
needed depending on the configuration.
Paul
----- Original Message -----
From: "Glaeser, Dennis A" <dennis.glaeser(at)eds.com>
Subject: AeroElectric-List: Re: Alternator characteristics
>
>
> I have a question regarding:
>
> --snip--
> WE still have to wait 30 ms or longer for the "B" lead contactor to open
> and
> during this there is no OV protection and the load dump from the stored
> energy is still dumping onto the bus. If there is a battery present its
> likely a non event voltage wise. However if the mode of operation is
> alternator only then there can be 20+ volt voltage spike on top of the 12v
> nominal voltage. A mag equipped engine will press on but your avionics may
> be toasted
> --snip--
>
> I probably missed something along the way, but when would the mode of
> operation be 'alternator only'? Is this to allow for a failed battery, or
> some other scenario? I thought the purpose of the On-On-On switch (or
> Cessna split rocker) was to preclude taking the battery off-line while the
> alternator is connected.
>
> Dennis Glaeser
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Circuit breaker ratings for OVP |
One of the likely circuit breaker candidates is the W23 5 amp unit. Its
reported this is used by 3 major certificated aircraft and is approved by
the FAA.
This CB, as are all the others I have looked at, define the 'time to open
range' at various over current levels up to 1,000% of rating. Interesting
that they all stop at 1,000%. That is 50 amps for a 5 amp breaker. Its also
10 times rated current.
Now the W23 specification data sheet states the following:
Resettable Overload capacity: Ten times rated current.
What does this mean??
This is defined in the industry as:
"RESETTABLE OVERLOAD CAPACITY
* Represents the maximum current the circuit protector is capable of
interrupting without damaging itself."
What does this mean??
It means that the CB may not meet specifications if the current being broken
exceeds ten times (or in this case 50 amps) its ratings.
I checked with a long time IA and he said that means the CB must be replaced
if there is a known overcurrent trip on a critical to flight item. The
alternator is considered a critical to flight component. Bsically if a part
is known to have been subjected to an out of specification condition that
might affest its function it must be replaced, testing is not good enough.
The only conclusion I can come to is that any crowbar design that is not
current limited to 50 amps will require the CB to be replaced if its tripped
by and crowbar OVP in a certificated aircraft.
For experimental its not the same but who would not want to replace a
potentially damaged CB that might not work as specified??
As I have previously suggested there is a simple fix to those who are using
the crowbar OVP and that is to add a 1/4 ohm resistor in series that will
limit the current to 50 amps or less and will not prevent the proper and
intended function of the OVP.
Both Bob and I have agreed that the typical OVP being discussed has a
tripping current in excess of 100 amps, that we disagree on the amount of
current over 100 amps is not really important.
I do not know if the certified LR-x series of regulators can overcurrent the
CB (worst case over 50 amps) but its worth investigating.
I can see no reason for not making this improvement and eliminating the
potential damage to the CB from being over stressed.
Note that the ability of the CB to break up to 2,000 amps is very different
from being able to survive this with no damage. Essentially what the mfgr's
are saying is that the CB is reusable as a CB up to ten times its ratings
and will open under hundreds of times its ratings but then should be treated
like a fuse and be replaced.
Paul
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator characteristics |
My point was not that OVP will prevent problems but that there are so many
out there who think that the battery will prevent OVP or at least keep the
OV under sort of control.
I think we can agree that some OVP method is needed regardless of the
likelyhood of a total runaway alternator no matter how unlikely because of
the potential results.
My concern is there are many thousands of aircraft out there with NO OVP of
any kind.
However there are different types and methods of OVP and I believe that one
size does not fit all cases.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Alternator characteristics
>
>
>
>>
>>
>>I have tested a battery with a constant current 40 amp supply. The battery
>>was a concord 25ah aircraft battery.
>>
>>A battery that is fully charged acts more like a capacitor than a sink for
>>excess current. The test battery terminal voltage was well above 20V in
>>under 30 seconds and going up fast.
>>
>>I have concluded (and the experts agree) that a battery will not clamp the
>>voltage if there is a lot of current that the battery does not need for
>>charging, it just goes into overcharge mode and away we go :-)
>>
>>A battery is great as a capacitor for load dumps and other short term
>>overcurrents from the alternator but useless in the case of a long term
>>failure like a failed hi regulator, Thus the need for some sort of OVP.
>>
>>You can consider the OVP as a voltage clamp while opening the CB that
>>kills
>>the field and or opens the "B" lead.
>>
>>The subject failure is quite rare.
>
>
> Agreed. Revision B to the White Paper discusses the battery's role
> in OV dynamics. There are two or perhaps three phases to the
> rise in voltage across an overcharged battery. The first is fairly
> fast and operates in accordance with a shift in the battery's
> chemistry to morph from energy supplier to energy absorber. There's
> a transition area I've described as a "knee" in the curve before the
> batter goes into the grunt mode of sopping up all the energy it can.
> The third phase is a function of the battery's "load" impedance on
> the overcharge source. Note that this impedance is decidedly larger
> than when the battery is a source of energy.
>
> Time from onset of OV condition to the end of the "knee" is a few
> hundred milliseconds max . . . PLENTY of time for any ov detection
> and mitigation system to rope the alternator and bring it to the
> ground. The max voltage to be expected based on relatively hefty
> alternators and batteries at or near end of life is 20 volts. This
> is where the 20v for one second requirement in DO-160 came from.
>
> It's true that an unabated OV event can carry the system to
> spectacular and potentially smelly heights. But it takes a lot
> of time compared to the window in which we EXPECT an ov protection
> system to do its job.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| Subject: | Re: Circuit breaker ratings for OVP |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi Paul,
You make an interesting point. I wonder, how often we will know that
a tripped breaker did so within the spec'ed range? In other words, if a
breaker trips because of a wiring fault, is there any way to know that the
1000% spec wasn't violated. I suppose what that suggests is that if
your airplane chafes off a piece of insulation and then pops a breaker,
the only approved way to return it to service is to repair the wire, chafe
protect it, AND replace the breaker. Is that right?
Regards,
Matt-
VE N34RD, C150 N714BK
>
>
> One of the likely circuit breaker candidates is the W23 5 amp unit. Its
> reported this is used by 3 major certificated aircraft and is approved
> by the FAA.
>
> This CB, as are all the others I have looked at, define the 'time to
> open range' at various over current levels up to 1,000% of rating.
> Interesting that they all stop at 1,000%. That is 50 amps for a 5 amp
> breaker. Its also 10 times rated current.
>
> Now the W23 specification data sheet states the following:
>
> Resettable Overload capacity: Ten times rated current.
>
> What does this mean??
>
> This is defined in the industry as:
>
> "RESETTABLE OVERLOAD CAPACITY
> * Represents the maximum current the circuit protector is capable of
> interrupting without damaging itself."
>
> What does this mean??
> It means that the CB may not meet specifications if the current being
> broken exceeds ten times (or in this case 50 amps) its ratings.
>
> I checked with a long time IA and he said that means the CB must be
> replaced if there is a known overcurrent trip on a critical to flight
> item. The alternator is considered a critical to flight component.
> Bsically if a part is known to have been subjected to an out of
> specification condition that might affest its function it must be
> replaced, testing is not good enough.
>
> The only conclusion I can come to is that any crowbar design that is not
> current limited to 50 amps will require the CB to be replaced if its
> tripped by and crowbar OVP in a certificated aircraft.
>
> For experimental its not the same but who would not want to replace a
> potentially damaged CB that might not work as specified??
>
> As I have previously suggested there is a simple fix to those who are
> using the crowbar OVP and that is to add a 1/4 ohm resistor in series
> that will limit the current to 50 amps or less and will not prevent the
> proper and intended function of the OVP.
>
> Both Bob and I have agreed that the typical OVP being discussed has a
> tripping current in excess of 100 amps, that we disagree on the amount
> of current over 100 amps is not really important.
>
> I do not know if the certified LR-x series of regulators can overcurrent
> the CB (worst case over 50 amps) but its worth investigating.
>
> I can see no reason for not making this improvement and eliminating the
> potential damage to the CB from being over stressed.
>
> Note that the ability of the CB to break up to 2,000 amps is very
> different from being able to survive this with no damage. Essentially
> what the mfgr's are saying is that the CB is reusable as a CB up to ten
> times its ratings and will open under hundreds of times its ratings but
> then should be treated like a fuse and be replaced.
>
>
> Paul
>
>
________________________________________________________________________________
| From: | rd2(at)evenlink.com |
Stein,
>The Alt Hold & V.Speed are relatively easy, and both TruTrak as well as Trio
>are offering a "Altitude Hold" with Vertical Speed.
Thanks for the above info.
>The GS part is much more complex, because now you're following a NAV signal,
>not a GPS or simple referential air data.
The AP already has 1 nav input, but that is used to follow the localizer.
>I think the easiest way to accomplish what you want is to simply buy an
>exisiting autopilot with that functionality!
This one part will cost me more than 2 cents - more like quite a few grand. :)
(I got a proposal for over 10K; nocando). I'd like to read up on the
subjest, but can't find sources yet. Not to say that I'd do a mod and trust
it to follow the GS in hard IFR.
March 15, 2005 - March 22, 2005
AeroElectric-Archive.digest.vol-ed