Today's Message Index:
----------------------
1. 07:01 AM - Re: Re: magneto timing buzz box (Scott Derrick)
2. 07:04 AM - Re: FW: Splice 6AWG Wire (Dave Morris \)
3. 07:26 AM - Re: Re: magneto timing buzz box (Robert L. Nuckolls, III)
4. 08:32 AM - Re: RE load dump (Paul Messinger)
5. 10:59 AM - Re: RE load dump (Robert L. Nuckolls, III)
6. 11:43 AM - Re: RE load dump (Paul McAllister)
7. 01:35 PM - Re: RE load dump (Steve Hunt)
8. 01:49 PM - Re: FW: Splice 6AWG Wire (KITFOXZ@aol.com)
9. 02:38 PM - Re: RE load dump from a novice point of view (Frank Stringham)
10. 05:31 PM - Paul M (LarryRobertHelming)
11. 06:05 PM - Re: FW: Splice 6AWG Wire (Robert L. Nuckolls, III)
12. 06:12 PM - Re: RE load dump (Robert L. Nuckolls, III)
13. 06:16 PM - Re: RE load dump from a novice point of view (Robert L. Nuckolls, III)
14. 06:38 PM - Re: Breaker Interrupt Rating (Tom Velvick)
15. 07:14 PM - Re: LVW problem (N1deltawhiskey@aol.com)
16. 09:18 PM - Re: RE load dump (John Schroeder)
Message 1
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| Subject: | Re: magneto timing buzz box |
--> AeroElectric-List message posted by: Scott Derrick <scott@tnstaafl.net>
Greg,
thanks for the tip. My orders in for one...
Scott
Greg Campbell wrote:
>--> AeroElectric-List message posted by: "Greg Campbell" <GregCampbellUSA@comcast.net>
>
>Take a look at the $25 kit from www.MagnetoTimer.com
>and see if that meets your needs.
>
>I've built two - it's a fun little soldering project, all the parts
>are included and identified (taped to the instruction sheet).
>About an hour of fitting & soldering and you've got a nice tool.
>
>The leads coil up and stow inside the open front of the plastic case.
>
>Greg
>
>
>.
>
>
>
Message 2
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| Subject: | Re: FW: Splice 6AWG Wire |
--> AeroElectric-List message posted by: "Dave Morris \"BigD\"" <BigD@DaveMorris.com>
I used this technique to put ring terminals on 2 and 4 gauge wire. Works
really well and takes about 5 seconds to heat it up.
Dave Morris
At 11:38 PM 9/17/2005, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><nuckollsr@cox.net>
>
> Now, if you have a really efficient iron (like the Metcal
> series) you can easily solder this size wire with the 35
> watt tool. Alternatively, check out your local Home Depot
> or Lowes for a Bernz-O-Matic ST100T butane torch. They
> sell for about $10 and you'll need a $4 fuel cannister.
>
>http://tools.batauto.com/index.php?crn=234&rn=1123&action=show_detail&PHPSESSID=cdea544011802efadd1901040779d172
>
> This is a very hi quality alternative to a pencil butane
> torch found in hobby shops and Harbor Freight. I give
> these BernzOMatic torches away at my weekend seminars.
>
> Use some 60/40 or 63/37 electronic solder to join strands
> of the wires. Oh, yes . . . be sure to put 1 or 2 chunks
> of heatshrink on the pigtails BEFORE you begin all this.
> It may be VERY hard to put it on later!
Message 3
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| Subject: | Re: magneto timing buzz box |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 07:58 AM 9/18/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: Scott Derrick <scott@tnstaafl.net>
>
>Greg,
>
>thanks for the tip. My orders in for one...
>
>Scott
Let me know your impressions of its usefulness . . .
Bob . . .
Message 4
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
I consider the entire subject (crow bar currents) closed. I feel no need to
continue based on your statements as its simply not worth my time to reply.
Until my comments are accepted as fact and we can get past that and deal
with the real issues the ridicule of my test results clearly says it was a
mistake to ever start this in the beginning. Further the snide remarks from
others does not help clear the air.
On the load dump test:
Here is a quick review of the results
1. Eric and I gave up and I declined to publish in the detail you seem to
need. Simply not worth the time that would be needed to reply to your
disbelief or need to duplicate tests that may require the exact parts (as
part type is not enough) and this thread is proof of that.
2. The testing showed that there was NO problem with normal load dump as
long as there was a battery connected to the system and NO OVP of your
design connected (see below).
3. We also investigated the case of NO battery as many want to have that as
a backup mode of flight. As I have personally seen 3 aircraft batteries fail
open in flight (two concord RG type and one Gill), I felt it was worth
including this in the testing. Your OVP module failed 100% of the time (in
even small load dumps) but that was expected as it clearly was not designed
to support that mode of operation (no battery). Adding a 25,000 MFD
capacitor reduced the alternator ripple voltage but did not control the
small load sumps and your OVP continued to trip 100% of the time, again not
unexpected as the trip time was far too short to allow even a cap filtered
load dump to pass. Here transorbs worked well to clamp the peak load dump
voltage spike. Adjusting the OPV trip voltage higher to allow for transorb
clamping resolves the tripping issue with the OVP
3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and two
made. Both had false trips 100% of the time when a large load was switched
ON. This led to a simple design review of this OVP and we discovered there
were two design errors that made the OVP sensitive to simple changes in bus
voltage etc. One has been recently posted and the other is a sensitivity to
contact bounce and the fast trip time. Besides the OVP design issues the
contactor applying the load has contact bounce that was triggering the OVP.
There was no further effort on your OVP design (by us) as the design concept
was very old and there are simple IC parts available that made a simple
modern design with adjustable trip times off the shelf. Why try to fix
something that is decades behind the current technology?? as the new design
had built-in production against false triggering it was a win win solution.
Further there is the simple opening of the contactor coil and Zero crowbar
current as the design does not use a crowbar.
The solution we proposed was to be sure the OVP trip time was much longer
than relay/contactor contact bounce (actually longer than a expected load
dump event). Contact bounce on load removal also caused problems. I did post
a reference from a major relay manufacturer that contact bounce on contact
opening WITH a diode across the coil was very bad idea and not only was
there contact bounce on opening there was the possibility of contact welding
on opening. Use of transorbs clipped the load dump transient and everything
worked right thru the transient even with no battery on line.
4. There was widespread (reported by Vans, and several builders who directly
contacted me off list) false tripping by the OVP and resulting alternator
failure where the alternator was internally regulated and the "B" lead
contactor was the common type that not only bounced on opening (due largely
to the recommended diode) and also to the resulting load dump peak voltage
that greatly exceeded the contactor maximum contact voltage rating. Heavy
contact arcing was documented. This resulted in the recommended Kilovac
contactor as its the only reasonable cost contactor with the proper ratings
and there is no coil diode to cause problems on contact opening.
5. We then had a system design solution with a no false tripping OVP and a
"B" lead contactor that did not damage the alternator. Eric is now selling
the OVP design and has on occasion the Kilovac contactors that allow safe
"B" lead opening.
6. I further investigated "rebuilt alternators" and found the term
misleading. Only parts that were failed were replaced. The term should be
repaired not rebuilt. The popular ND 55 amp alternator has been around for
more than 20 years and many have been rebuilt several times. Who knows the
quality of the current regulator? Thus only brand NEW alternators should be
used.
7. Replacing the fast trip and occasional false tripping OVP with a modern
design eliminates false trips. Eliminating the Crow bar eliminated the hi
current and its side affects (see below). If used, the proper "B" lead
contactor will prevent alternator damage often caused by the improperly used
common contactor that is not designed or specified for this specific
application and further hindered with the incorrect application of a diode
across the coil against major manufacturers worked wide. In fact the common
diode across the coil is not recommended anywhere any time by relay
manufacturers. That its very common in use does not mean its a good
approach, It simply means that most engineers are lazy and copy what has
been done in the past rather that research what is recommended so the diode
persists even with its being the last and worst choice in a list of options.
IN conclusion the test results showed that much of the alternator failures
were the direct result of the OVP design and associated contactor. Its not
known if poor alternator regulators were a factor but even good ones are
very likely to be damaged by the current design contactor used. Its clear
that the contactor used has a very high potential of regulator damage and
when coupled with a false trip prone (in some as yet defined aircraft wiring
or operations) is the root cause.
Use a modern non-crowbar OVP design and a contactor designed for the
application resolved most of the problem. Its not possible to ignore the
likely hood of lesser quality regulators in rebuilt alternators so only new
alternators should be used.
With the demonstrated extremely high reliability of the ND brand of
internally regulated alternators is very questionable that there is a need
for more that having the OVP simply remove the voltage to "I" lead (the
field control lead) that shuts down the alternator. I have been unable to
find any repair shop that has ever heard of an ND alternator having
uncontrolled runaway failure. No output or hi output that is still
controllable with the "I" lead. Prop bolts or crank shafts are more likely
to fail and yes I have a report of a light twin having both engines prop
bolts failing.
Now for the hi current related problems.
In an steel tube reinforced cockpit like the Glastar (or other production
aircraft) its been proven that even the normal bus loads can magnetize the
tube structure and cause compass errors of as high as 30 degrees. I
previously referenced a manufacturers mandatory service bulletin that
addressed this issue and also discussed with a owner of that type aircraft
that had it happen to him. He is highly educated and a long time IA. The
compass in question was a suspended well above the affected tubes
This tells me that even 50 amp buss circuits need special wire routing and
forget the 100+++ current transients from a crow bar.
This alone says if you have a steel tubular cabin be careful and forget a
crow bar approach.
In any event this is my last word on either subject even if the misquoting
etc continues.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
Subject: Re: AeroElectric-List: RE: Breaker Interrupt Rating
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> At 01:02 PM 9/17/2005 -0700, you wrote:
>
>>--> AeroElectric-List message posted by: "Paul Messinger"
>><paulm@olypen.com>
>>
>>Bob;
>>
>>I DID post (to this list) the exact specific technical parts etc. details
>>of
>>my test and you seemed never recognize that fact.
>
> Forgive me. I WAS watching for such information since I was the
> one who requested it. Can you give me an approximate date or repeat
> your post. I'll so search the archives if necessary. Give me one
> part number you cited. It will make the search so much faster.
>
>> That I used words and not
>>a schematic is not important in this case as a schematic is not needed
>>with
>>such a simple circuit. I did use a different wiring diagram (of your
>>schematic) to duplicate what is in my aircraft however.
>
> Then is it a fair presumption that as an skilled and articulate
> engineer that you've documented that portion of your system's
> wiring in a manner that can be scanned and shared?
>
>
>>But you cannot duplicate my results (as I under stand what you mean by
>>duplicate) unless you use the exact same parts I used. The same identical
>>part, not a part of the same brand and part number is required in this
>>case
>>because of the very wide variation in the parts tolerances.
>
> Absolutely! I've never done a test report without identifying
> or at least making full disclosure of parts used, techniques,
> measurements, etc. I'd be pleased for you to take the parts I
> used in
>
> http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf
>
> and show me how I mis-read or mis-interpreted data at the risk
> of making a bad deduction. You seem to accept the test results
> I posted but counter with "that's not what I got with MY test."
> Fine . . . tell us how you did it.
>
>
>>Only if a worst case analysis is properly done and the range of test
>>results
>>is determined can any test be duplicated by another using different
>>physical
>>parts of the same part number. The part to part variation in most cases
>>and
>>clearly in this case is simply too large.
>
> I'm mystified as to this part-to-part variation you cite.
>
>>Crow bar short circuit currents can vary from well under 100 amps to over
>>400 amps depending on the parts used and the wiring diagram used to
>>implement the same schematic.
>
> I don't doubt it . . . but I'm still trying to visualize the
> 400A case.
>
>>Thus any test that results in a current from around 100 amps to around 400
>>amps is in fact a duplication of another's test results in this case.
>>
>>Where there are small parts variations the duplicated test results will be
>>much closer but NEVER identical.
>
> You don't have to sell me on stacked up variability and test
> tolerances . . . I've been doing this since high school
> physics.
>
>
>>For example the following is true:
>>
>>#1 CB ratings vary widely in resistance and trip time, in fact, close to
>>a
>>10 -1 variation. between parts of the same brand and parts from other
>>brands. Nothing strange about My CB having an internal resistance 1/10 of
>>the one you used. CB internal resistance can and does vary from approx
>>0.003
>>to over 0.030 ohms; a 10-1 variation
>
> This I really need to see. What brand and part number exhibits
> such variability? The problem I'm having is that trip characteristics
> are an I(squared)*T event that depends on heat generated within
> the current sensing part of the breaker. ANY breaker that shows
> a 10:1 variability in resistance should be expected to show
> a similar variability in trip characteristics. There are no
> manufacturers I work with that would offer me such a product.
>
> Gee, a 5A breaker that can open anywhere between 2.5 and 25 amps!
>
>
>>#2 Battery internal resistance also varies again as much as 10-1 depending
>>on the battery brand and ratings. My batteries have 1/5 to 1/10 the
>>internal
>>resistance of your battery. But then I do not use the Panasonic brand or
>>similar types.I do use a very popular PS625 (dual at that) battery with
>>much
>>higher specifications in most important parameters. Not that the Panasonic
>>is bad but its not nearly the same in several (important to me) electrical
>>specifications.
>
> As I've repeated many times, I don't care if your battery
> is ZERO ohms. There's a rational, recommended installation
> technique for using my products where the MAJOR contributor
> of loop resistance is wiring, a minor contributor is circuit
> breaker heater resistance with so small an amount coming from
> the battery and fatwires that they can be ignored. Nonetheless,
> I'm intently interested in your .0035 to .0017 ohm battery.
> Do I recall that you're building a Subaru powered two-place?
> Batteries I can find with this level of performance start out
> at 60 pounds and go up from there. I presume you ARE planning
> on carrying passengers in this airplane . . .
>
>
>>#3 My wiring was an exact duplicate of what I have in my aircraft and is a
>>fraction of what you had in your test. My wiring is less that 1/2 the
>>internal resistance of your test wiring.
>
> Very good. The systems I recommend and illustrate in the Z-figures
> are rooted in practices found in the vast majority of Certified
> and OBAM iron. Of course one should not toss away lots of
> performance in wire drops and soggy batteries . . . but then,
> wiring everything with 00 gage and installing batteries that
> would crank a Detroit Diesel in a N. Dakota winter has some
> seriously diminished returns on overall system design. If you
> have 1/2 the loop resistance illustrated in my experiments, you
> must have a rational for increased battery and wire sizes at the
> sacrifice of useful load. We'd be interested in understanding
> the design goals by which you arrived at this exceedingly low
> loss system.
>
>>I measures the battery internal resistance as well as the CB and wiring
>>resistances before and after the testing series.
>>
>>The same CB was used in the simulated worst case test where the current
>>was
>>700 amps and there were at least 50 tests of the real circuit where the
>>current was 400 amps. No degrading of any part including the SCR in your
>>crow bar circuit which was over stressed several times its max rating.
>
> Then no doubt you can tell me what the battery part number was, what
> circuit
> breaker was used, what SCR was used, what diameters and lengths of
> wires were used . . . I'll pay you my consulting fee for the time
> it takes you to type that data into a posting here on the list.
>
>
>>This overstressing and lack of damage does not mean its a good design idea
>>and more importantly does not mean that all CB's will survive with no
>>damage.
>>
>>In this case the main short current drivers are the Battery, CB and wiring
>>resistances.
>>
>>That alone suggests that 400 amps is easy to achieve as the circuit
>>resistance to get 400 amp vs. 130 amps only needs to decrease to 1/3 or
>>so.
>>
>>Bottom line: I had 6 EXPERT, experienced, real electrical engineers
>>review
>>what I have done and ALL agreed with my test setup and suggested 400 amps
>>was not the max current possible as I had not used the worst case analysis
>>parts.
>
> Then may we expect to see their names on the byline for a
> detailed report? As long you've opened the door to name dropping,
> I'll claim real signatures of dozens of folks representing systems
> designers, DERs, program managers, test pilots and test
> technicians who executed paperwork certifying this system on
> Mooney, Piper, Beech, Cessna and Cirrus aircraft. This is over
> and above thousands of OBAM aircraft customers who seem to be getting
> satisfactory performance from their purchases.
>
> For the moment, I have no greater assurances of the existence
> of your six "experts" than I do of the half dozen or so of
> my customers you claim were ALL having nuisance trip problems
> NONE of whom would call me for assistance and ALL of which declined
> an opportunity to exercise my well published 100% satisfaction
> or money back guarantee.
>
>>I had hoped this issue had gone away months ago as we will never agree. I
>>only post here when I feel my comments are being misquoted to the extreme.
>>Seems that will never end and frankly I am saddened that it seems to
>>continue.
>
> The List is a classroom. Folks will always be asking about these
> issues and as one of several teachers on the list, I have a duty
> to sort myth, old mechanic's tales, and bad science from
> fact as I understand it. If you want this discussion to end, then
> carry out your past threats never to post again. If you have
> facts to dispute, then be a teacher and publish counter balancing
> facts. Either is fine with me . . . but don't expect me not
> to continue to counter rumors, yours or anyone else's. I'm sure
> Greg Richter is fond of telling tales over a beer about how
> he crossed swords with that wild-eyed guy in Wichita and the
> telling probably gets better with each pitcher full. He too
> was amazingly reluctant to answering a single direct question.
> If you're ready to mark me off as hopeless, you're welcome to
> bow out . . .
>
> I've even offered $cash$ rewards for simple answers to
> specific questions. It would be worth it to me. My exorbitant
> consulting rate at the moment is $75/hour. If you could save
> me a hour of time digging around trying to figure out exactly
> how you arrive at some of your mystifying numbers, then
> I'd be money ahead to pay you cash for the data. I'd rather
> use the hour to add value to someone's airplane as opposed to
> sorting your jigsaw puzzle with many missing pieces. How about
> filling in your version of the pieces in the first figure on
> page 2 of the paper cited above and show us all how you
> generated a 400A crowbar event?
>
>
>>The basic issue of OVP crow bar short to open a CB is the real discussion
>>where you believe its a good approach and I disagree is the fundamental
>>issue and the short current is a distraction.
>
> Hmmm . . . at least it's devolved to a 'distraction' . . . there have
> been times past when the crowbar event could be expected to cause
> all manner of bad day including in-flight reset of EFIS systems
> and engine stoppage. If you have a better approach, you're
> most welcome to join the rest of us in the free marketplace.
>
>>Please do not snip this email as it tends to put my comments out of
>>context
>>and change the meaning/intent of my comment.
>>
>>Better yet simply do not reply and we can both put this stupid debate to
>>rest and get on with productive discussions.
>
> If it's stupid, it's only because you're not debating. Any high school
> debate teacher would have tossed you out of this classroom years ago.
> My physics teacher would have tossed you out of his class too. I saw
> him do it to a kid that "dry labbed" an important assignment. This is
> not a classroom on debate, it's a classroom of simple ideas and physics
> as they relate to building the best airplanes to have ever flown.
> Show us your setup, show us your work and show us your data.
>
> Okay, how's this for a productive topic:
>
> How do you propose we offer a means by which an OBAM aircraft
> community a means for installing an internally regulated alternator
> such that its operation transparent to the paradigm under which
> generators and alternators have been operated on aircraft since
> day-one to wit:
>
> (1) Absolute pilot control over engine drive power source.
>
> (2) Failure and hazard free switching of the engine driven power
> source at any time and under any conditions.
>
> . . . of course, answers to the above will offer the OBAM aircraft
> builder a means by which any attractive OV protection philosophy
> can be added assuming he/she so desires. These are the questions I
> thought
> you were going to answer when you went off to do the tests over a
> year ago. Presumably you have the data necessary to make considered
> recommendations. We're all ears.
>
> Bob . . .
>
>
>
Message 5
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:16 AM 9/18/2005 -0700, you wrote:
>--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
>
>I consider the entire subject (crow bar currents) closed. I feel no need to
>continue based on your statements as its simply not worth my time to reply.
>Until my comments are accepted as fact and we can get past that and deal
>with the real issues the ridicule of my test results clearly says it was a
>mistake to ever start this in the beginning. Further the snide remarks from
>others does not help clear the air.
I disagree. It was a VERY valuable discussion. One gains
confidence in teachers based on a history of an individual's
ability to impart understanding. The name behind the words is
immaterial when understanding is achieved . . . the only time a
name is important is when it identifies a source of words where
understanding is difficult if not impossible to achieve. E.g. I
didn't have to try many cups of McDonalds coffee to know that
it was fruitless to expect it to be any better in another
establishment with the same sign out front.
>On the load dump test:
>
>Here is a quick review of the results
>
>1. Eric and I gave up and I declined to publish in the detail you seem to
>need. Simply not worth the time that would be needed to reply to your
>disbelief or need to duplicate tests that may require the exact parts (as
>part type is not enough) and this thread is proof of that.
>
>2. The testing showed that there was NO problem with normal load dump as
>long as there was a battery connected to the system and NO OVP of your
>design connected (see below).
This was predictable, easily explained and understood . . .
>3. We also investigated the case of NO battery as many want to have that as
>a backup mode of flight. As I have personally seen 3 aircraft batteries fail
>open in flight (two concord RG type and one Gill), I felt it was worth
>including this in the testing.
Agreed . . .
>Your OVP module failed 100% of the time (in
>even small load dumps) but that was expected as it clearly was not designed
>to support that mode of operation (no battery).
You got that right. This was the first time in history of aviation
as far as I've studied it that no-battery operation was brought
forth as a design goal with alternators. Generators are very
friendly in the no-battery mode. We do it all the time in today's
fleet of bizjets. Had you asked me about performance of my
product before you mis-applied it, I would have predicted the
results you demonstrated. Had you asked for a modified product
to function under a new deign goal, I would have been pleased to
try.
>Adding a 25,000 MFD
>capacitor reduced the alternator ripple voltage but did not control the
>small load sumps and your OVP continued to trip 100% of the time, again not
>unexpected as the trip time was far too short to allow even a cap filtered
>load dump to pass.
Yup, water runs down hill and the sun comes up in the east . . .
> Here transorbs worked well to clamp the peak load dump
>voltage spike. Adjusting the OPV trip voltage higher to allow for transorb
>clamping resolves the tripping issue with the OVP
Or . . . one could increase the trip time-constant such that the
integrated waveform of the dump event does not add up to a value
greater than trip point . . . it's a new paradigm that needed to
be explored, values deduced, and goals established.
>3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and two
>made. Both had false trips 100% of the time when a large load was switched
>ON. This led to a simple design review of this OVP and we discovered there
>were two design errors that made the OVP sensitive to simple changes in bus
>voltage etc. One has been recently posted and the other is a sensitivity to
>contact bounce and the fast trip time. Besides the OVP design issues the
>contactor applying the load has contact bounce that was triggering the OVP.
Gee Paul, I thought you were going to participate in a new
discussion about energies and dynamics of the load-dump event
as presented by alternators you had the facilities to test.
All you've done is moved off on another whack at the crowbar
OVP system which was originally designed to meet different goals and
modified as field experience suggested. You never once asked me
to participate in the gathering and analysis of data nor in the
deduction of solutions to meet your desires . . .which is the
core of my life's work as an engineer. Instead you simply
threw "rocks". You got really stirred up when instead of cowering
and capitulating under your barrage, I fielded the suckers and
of the community know them as such.
>There was no further effort on your OVP design (by us) as the design concept
>was very old and there are simple IC parts available that made a simple
>modern design with adjustable trip times off the shelf. Why try to fix
>something that is decades behind the current technology?? as the new design
>had built-in production against false triggering it was a win win solution.
>Further there is the simple opening of the contactor coil and Zero crowbar
>current as the design does not use a crowbar.
This was never an argument. Use any OVP design philosophy that floats
your boat. The fact that you're asking something I did to meet your
new, unspecified and unanswered design goals after I've designed
and delivered the product to other goals is truly astounding. If
you use a wrench to drive nails and then complain to the wrench supplier
about the problems you're having, the speciousness of your comments
become obvious.
>The solution we proposed was to be sure the OVP trip time was much longer
>than relay/contactor contact bounce (actually longer than a expected load
>dump event). Contact bounce on load removal also caused problems. I did post
>a reference from a major relay manufacturer that contact bounce on contact
>opening WITH a diode across the coil was very bad idea and not only was
>there contact bounce on opening there was the possibility of contact welding
>on opening.
This is BS and I'm working on the paper and test report to show why.
But we can save that 'discussion' for another time.
> Use of transorbs clipped the load dump transient and everything
>worked right thru the transient even with no battery on line.
EXCELLENT! Now, how long was the load dump event? What was its amplitude?
How many Joules of energy were dumped into the transorbs. What RPM were
you running the alternator. Would the transorbs you selected be reasonably
expected to handle a moderately loaded alternator running at over 10,000
rpm?
>4. There was widespread (reported by Vans, and several builders who directly
>contacted me off list) false tripping by the OVP and resulting alternator
>failure where the alternator was internally regulated and the "B" lead
>contactor was the common type that not only bounced on opening (due largely
>to the recommended diode) and also to the resulting load dump peak voltage
>that greatly exceeded the contactor maximum contact voltage rating. Heavy
>contact arcing was documented. This resulted in the recommended Kilovac
>contactor as its the only reasonable cost contactor with the proper ratings
>and there is no coil diode to cause problems on contact opening.
You've stirred a whole lot of ingredients into this paragraph. First,
vulnerability of the alternator to damage was a direct function of adding
a means of positive control. It had to do with adding a b-lead contactor.
It didn't matter what contactor was used, whether or not a diode was
present across the contactor or whether OVP was present. The act of
turning the alternator OFF for any reason while loaded was the proximate
cause of damage to the alternator due to inability to withstand its
own load-dump event.
Yes, the contactor's switching limits needed review . . . yes, there
were (you say but don't document) nuisance trip issues. I've seen
hundreds of closure traces that demonstrate bounce in contacts of
relays, breakers and switches as contacts come together. I've not
seen contacts that are moving apart suddenly decided they're going
the wrong direction and come back together for some period of time.
Can you explain? Do you have any traces? What parts did this?
What was the source of forcing moments that caused parts that
were separating to reverse direction?
>5. We then had a system design solution with a no false tripping OVP and a
>"B" lead contactor that did not damage the alternator. Eric is now selling
>the OVP design and has on occasion the Kilovac contactors that allow safe
>"B" lead opening.
Super! Are you telling me that this is your recommendation for
absolute control of alternators? Gee, except for establishment
and satisfaction of new design goals, this looks like Figure
Z-24 that I published years ago . . . care to share any of the
numbers that will help the rest of the world gain confidence
in your recommendations?
>6. I further investigated "rebuilt alternators" and found the term
>misleading. Only parts that were failed were replaced. The term should be
>repaired not rebuilt. The popular ND 55 amp alternator has been around for
>more than 20 years and many have been rebuilt several times. Who knows the
>quality of the current regulator? Thus only brand NEW alternators should be
>used.
A no brainer . . . if one accepts the limitations of selecting
one's alternator from a small fraction of the total number of sources
for alternators that MIGHT be perfectly okay under YOUR design
goals. You've accused most engineers of being lazy, why did you
stop short of crafting techniques that would allow the OBAM aircraft
builder to apply ANY modern alternator "rebuilt" or not with the
only risk being short service life? That's my design goal and yes,
it will take some more work. The problem is time and equipment -
not laziness.
>7. Replacing the fast trip and occasional false tripping OVP with a modern
>design
(that discards Mil-STD-704 philosophies in place for decades and
marches of to the beat of Paul's new drum . . .)
>. . . eliminates false trips. Eliminating the Crow bar eliminated the hi
>current and its side affects (see below). If used, the proper "B" lead
>contactor will prevent alternator damage often caused by the improperly used
>common contactor that is not designed or specified for this specific
>application and further hindered with the incorrect application of a diode
>across the coil against major manufacturers worked wide. In fact the common
>diode across the coil is not recommended anywhere any time by relay
>manufacturers.
Yup, I've read the papers cited here on the list . . . and it didn't
take 5 minutes at the bench to discount their value as drivers for
our design goals. The amazing thing was that they were published
by big names in the industry by folks with long lists of credentials.
They took lots of good data, published some neat 'scope traces and
then drew conclusions that could have been but were not directly
measured . . . Others have read the papers and assumed that the
stature and authority of the authors was sufficient to broadly apply
their suppositions with almost religious fervor. Which underscores an
observation I made years ago . . . just because one might have run a
successful restaurant doesn't make them a good chef.
> . . . That its very common in use does not mean its a good
>approach, It simply means that most engineers are lazy and copy what has
>been done in the past rather that research what is recommended so the diode
>persists even with its being the last and worst choice in a list of options.
You betcha. Did YOU bother to repeat their experiments and deduce
for yourself the effects of diode-across-the-coil as we used it?
This begs the question as to who is lazy here and who worships at
the altars of Tyco-Amp, P&B, etc.
>IN conclusion the test results showed that much of the alternator failures
>were the direct result of the OVP design and associated contactor. Its not
>known if poor alternator regulators were a factor but even good ones are
>very likely to be damaged by the current design contactor used. Its clear
>that the contactor used has a very high potential of regulator damage and
>when coupled with a false trip prone (in some as yet defined aircraft wiring
>or operations) is the root cause.
Your train of thought for cause/effect is truly amazing . . . I'm going
to save these threads for future reference. They'll be great teaching
tools.
>Use a modern non-crowbar OVP design and a contactor designed for the
>application resolved most of the problem. Its not possible to ignore the
>likely hood of lesser quality regulators in rebuilt alternators so only new
>alternators should be used.
>
>With the demonstrated extremely high reliability of the ND brand of
>internally regulated alternators is very questionable that there is a need
>for more that having the OVP simply remove the voltage to "I" lead (the
>field control lead) that shuts down the alternator. I have been unable to
>find any repair shop that has ever heard of an ND alternator having
>uncontrolled runaway failure. No output or hi output that is still
>controllable with the "I" lead. Prop bolts or crank shafts are more likely
>to fail and yes I have a report of a light twin having both engines prop
>bolts failing.
Okay, if I republish Z-24 then all I need to do is upgrade the
contactor, recommend Eric's latest and greatest OVP product, and
add a transorb (also Eric's product?). And finally, limit recommendations
to brand new ND alternators? If Eric's OVP is in place is a builder
on shaky ground by NOT using a new alternator . . . or even an ND
product? Can you articulate the new design goals in the form of a white
paper (the new Bible) that leads other designers down the path to Nirvana
along with guidance as to the nature and magnitude of conditions to expect?
(No, don't answer that. Let's go ahead and accept this as your "last word")
>Now for the hi current related problems.
>
>In an steel tube reinforced cockpit like the Glastar (or other production
>aircraft) its been proven that even the normal bus loads can magnetize the
>tube structure and cause compass errors of as high as 30 degrees. I
>previously referenced a manufacturers mandatory service bulletin that
>addressed this issue and also discussed with a owner of that type aircraft
>that had it happen to him. He is highly educated and a long time IA. The
>compass in question was a suspended well above the affected tubes
>
>This tells me that even 50 amp buss circuits need special wire routing and
>forget the 100+++ current transients from a crow bar.
>
>This alone says if you have a steel tubular cabin be careful and forget a
>crow bar approach.
This was the great and evil "side effect"? Gee Paul, wouldn't
it be a good thing to simply NOT run high currents through the
structure? Cranking the engine runs far more current (with higher
inrushes) than a crowbar event will ever generate. The starter
event happens every flight-cycle. The crowbar event is much smaller
and may never happen.
It's apparent to me that your primary driver in this exchange
has been a vendetta against one who would have the audacity to
question your autocracy in the non-dissemination of information
combined with loads of un-substantiated advice. I don't believe
this discussion had anything to do with science, the art of
building reliable systems or the enthusiastic exchange of
simple-ideas for which good teachers are noted.
>In any event this is my last word on either subject even if the misquoting
>etc continues.
I have not snipped anything from your post so I cannot be accused
of any mis-quotation. It's obvious that you have no appreciation
for what it means to be a teacher or a responsible member of
an engineering community. Since you failed to substantiate any of
your allegations with data and cannot or will not answer any simple
direct question, I must conclude that this being your "last word"
on the matter is no loss to the OBAM aviation community. I look
forward to spending time on more fruitful and honorable endeavors.
As soon as I have time and access to the equipment, I'll repeat the
tests you claim to have conducted and publish the results here and
on my website. Please ignore them . . . there are plenty of sharp
heads on the list who will help me refine my studies from which
well considered design goals can be crafted and satisfied.
I wish you well in your new job.
Bob . . .
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "Paul McAllister" <paul.mcallister@qia.net>
Paul,
At the risk of being accused of "snipping" your email, or offering snide
remarks, this is truly a case of an expression we use in engineering shop
where I work (a $15 billion /year company)
It goes like, "In god we trust, everyone else bring data". Please share it,
many of us may learn something new.
With that said, this has been a truly enlightening discussion and the debate
has taught me a lot (not only about engineering)
Regards, Paul
> --> AeroElectric-List message posted by: "Paul Messinger"
> <paulm@olypen.com>
>
> I consider the entire subject (crow bar currents) closed. I feel no need
> to
> continue based on your statements as its simply not worth my time to
> reply.
> Until my comments are accepted as fact and we can get past that and deal
> with the real issues the ridicule of my test results clearly says it was a
> mistake to ever start this in the beginning. Further the snide remarks
> from
> others does not help clear the air.
>
Message 7
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "Steve Hunt" <stephen.hunt19@btinternet.com>
Hi Bob
Wow! I just joined............ I want to ask you if you think it OK for me
to proceed with my effort at hooking up my Vans 60 A int regulated alt as
follows. (I am no engineer, have little electrical knowledge)I have a B& C
cont rated contactor on the B lead which is switched by the second throw of
my Batt/Alt sw (2-10). I have, as yet no crowbar. I intend to always start
with alt switched off and stopping eng with alt switched on. I dont know how
I got here as I have the lost the thread of the latest advice and am feeling
confused. The loom all laid up, panel cut. I was ready to go and then got
hopelessly lost trying to follow this. Whilst it may not be the best
solution Bob, will this work?
thanks in anticipation,Steve
-----
From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
Subject: Re: AeroElectric-List: RE load dump
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> At 08:16 AM 9/18/2005 -0700, you wrote:
>
>>--> AeroElectric-List message posted by: "Paul Messinger"
>><paulm@olypen.com>
>>
>>I consider the entire subject (crow bar currents) closed. I feel no need
>>to
>>continue based on your statements as its simply not worth my time to
>>reply.
>>Until my comments are accepted as fact and we can get past that and deal
>>with the real issues the ridicule of my test results clearly says it was a
>>mistake to ever start this in the beginning. Further the snide remarks
>>from
>>others does not help clear the air.
>
> I disagree. It was a VERY valuable discussion. One gains
> confidence in teachers based on a history of an individual's
> ability to impart understanding. The name behind the words is
> immaterial when understanding is achieved . . . the only time a
> name is important is when it identifies a source of words where
> understanding is difficult if not impossible to achieve. E.g. I
> didn't have to try many cups of McDonalds coffee to know that
> it was fruitless to expect it to be any better in another
> establishment with the same sign out front.
>
>
>>On the load dump test:
>>
>>Here is a quick review of the results
>>
>>1. Eric and I gave up and I declined to publish in the detail you seem to
>>need. Simply not worth the time that would be needed to reply to your
>>disbelief or need to duplicate tests that may require the exact parts (as
>>part type is not enough) and this thread is proof of that.
>>
>>2. The testing showed that there was NO problem with normal load dump as
>>long as there was a battery connected to the system and NO OVP of your
>>design connected (see below).
>
> This was predictable, easily explained and understood . . .
>
>
>>3. We also investigated the case of NO battery as many want to have that
>>as
>>a backup mode of flight. As I have personally seen 3 aircraft batteries
>>fail
>>open in flight (two concord RG type and one Gill), I felt it was worth
>>including this in the testing.
>
> Agreed . . .
>
>>Your OVP module failed 100% of the time (in
>>even small load dumps) but that was expected as it clearly was not
>>designed
>>to support that mode of operation (no battery).
>
>
> You got that right. This was the first time in history of aviation
> as far as I've studied it that no-battery operation was brought
> forth as a design goal with alternators. Generators are very
> friendly in the no-battery mode. We do it all the time in today's
> fleet of bizjets. Had you asked me about performance of my
> product before you mis-applied it, I would have predicted the
> results you demonstrated. Had you asked for a modified product
> to function under a new deign goal, I would have been pleased to
> try.
>
>>Adding a 25,000 MFD
>>capacitor reduced the alternator ripple voltage but did not control the
>>small load sumps and your OVP continued to trip 100% of the time, again
>>not
>>unexpected as the trip time was far too short to allow even a cap filtered
>>load dump to pass.
>
> Yup, water runs down hill and the sun comes up in the east . . .
>
>
>> Here transorbs worked well to clamp the peak load dump
>>voltage spike. Adjusting the OPV trip voltage higher to allow for transorb
>>clamping resolves the tripping issue with the OVP
>
> Or . . . one could increase the trip time-constant such that the
> integrated waveform of the dump event does not add up to a value
> greater than trip point . . . it's a new paradigm that needed to
> be explored, values deduced, and goals established.
>
>
>>3. The OVP module you offer as plans was built up on a 1" x 1.5" pcb and
>>two
>>made. Both had false trips 100% of the time when a large load was switched
>>ON. This led to a simple design review of this OVP and we discovered there
>>were two design errors that made the OVP sensitive to simple changes in
>>bus
>>voltage etc. One has been recently posted and the other is a sensitivity
>>to
>>contact bounce and the fast trip time. Besides the OVP design issues the
>>contactor applying the load has contact bounce that was triggering the
>>OVP.
>
> Gee Paul, I thought you were going to participate in a new
> discussion about energies and dynamics of the load-dump event
> as presented by alternators you had the facilities to test.
> All you've done is moved off on another whack at the crowbar
> OVP system which was originally designed to meet different goals and
> modified as field experience suggested. You never once asked me
> to participate in the gathering and analysis of data nor in the
> deduction of solutions to meet your desires . . .which is the
> core of my life's work as an engineer. Instead you simply
> threw "rocks". You got really stirred up when instead of cowering
> and capitulating under your barrage, I fielded the suckers and
> of the community know them as such.
>
>
>>There was no further effort on your OVP design (by us) as the design
>>concept
>>was very old and there are simple IC parts available that made a simple
>>modern design with adjustable trip times off the shelf. Why try to fix
>>something that is decades behind the current technology?? as the new
>>design
>>had built-in production against false triggering it was a win win
>>solution.
>>Further there is the simple opening of the contactor coil and Zero crowbar
>>current as the design does not use a crowbar.
>
> This was never an argument. Use any OVP design philosophy that floats
> your boat. The fact that you're asking something I did to meet your
> new, unspecified and unanswered design goals after I've designed
> and delivered the product to other goals is truly astounding. If
> you use a wrench to drive nails and then complain to the wrench
> supplier
> about the problems you're having, the speciousness of your comments
> become obvious.
>
>
>>The solution we proposed was to be sure the OVP trip time was much longer
>>than relay/contactor contact bounce (actually longer than a expected load
>>dump event). Contact bounce on load removal also caused problems. I did
>>post
>>a reference from a major relay manufacturer that contact bounce on contact
>>opening WITH a diode across the coil was very bad idea and not only was
>>there contact bounce on opening there was the possibility of contact
>>welding
>>on opening.
>
> This is BS and I'm working on the paper and test report to show why.
> But we can save that 'discussion' for another time.
>
>> Use of transorbs clipped the load dump transient and everything
>>worked right thru the transient even with no battery on line.
>
> EXCELLENT! Now, how long was the load dump event? What was its
> amplitude?
> How many Joules of energy were dumped into the transorbs. What RPM were
> you running the alternator. Would the transorbs you selected be
> reasonably
> expected to handle a moderately loaded alternator running at over
> 10,000
> rpm?
>
>
>>4. There was widespread (reported by Vans, and several builders who
>>directly
>>contacted me off list) false tripping by the OVP and resulting alternator
>>failure where the alternator was internally regulated and the "B" lead
>>contactor was the common type that not only bounced on opening (due
>>largely
>>to the recommended diode) and also to the resulting load dump peak voltage
>>that greatly exceeded the contactor maximum contact voltage rating. Heavy
>>contact arcing was documented. This resulted in the recommended Kilovac
>>contactor as its the only reasonable cost contactor with the proper
>>ratings
>>and there is no coil diode to cause problems on contact opening.
>
> You've stirred a whole lot of ingredients into this paragraph. First,
> vulnerability of the alternator to damage was a direct function of
> adding
> a means of positive control. It had to do with adding a b-lead
> contactor.
> It didn't matter what contactor was used, whether or not a diode was
> present across the contactor or whether OVP was present. The act of
> turning the alternator OFF for any reason while loaded was the proximate
> cause of damage to the alternator due to inability to withstand its
> own load-dump event.
>
> Yes, the contactor's switching limits needed review . . . yes, there
> were (you say but don't document) nuisance trip issues. I've seen
> hundreds of closure traces that demonstrate bounce in contacts of
> relays, breakers and switches as contacts come together. I've not
> seen contacts that are moving apart suddenly decided they're going
> the wrong direction and come back together for some period of time.
> Can you explain? Do you have any traces? What parts did this?
> What was the source of forcing moments that caused parts that
> were separating to reverse direction?
>
>
>>5. We then had a system design solution with a no false tripping OVP and a
>>"B" lead contactor that did not damage the alternator. Eric is now selling
>>the OVP design and has on occasion the Kilovac contactors that allow safe
>>"B" lead opening.
>
> Super! Are you telling me that this is your recommendation for
> absolute control of alternators? Gee, except for establishment
> and satisfaction of new design goals, this looks like Figure
> Z-24 that I published years ago . . . care to share any of the
> numbers that will help the rest of the world gain confidence
> in your recommendations?
>
>
>>6. I further investigated "rebuilt alternators" and found the term
>>misleading. Only parts that were failed were replaced. The term should be
>>repaired not rebuilt. The popular ND 55 amp alternator has been around for
>>more than 20 years and many have been rebuilt several times. Who knows the
>>quality of the current regulator? Thus only brand NEW alternators should
>>be
>>used.
>
> A no brainer . . . if one accepts the limitations of selecting
> one's alternator from a small fraction of the total number of sources
> for alternators that MIGHT be perfectly okay under YOUR design
> goals. You've accused most engineers of being lazy, why did you
> stop short of crafting techniques that would allow the OBAM aircraft
> builder to apply ANY modern alternator "rebuilt" or not with the
> only risk being short service life? That's my design goal and yes,
> it will take some more work. The problem is time and equipment -
> not laziness.
>
>
>>7. Replacing the fast trip and occasional false tripping OVP with a modern
>>design
>
> (that discards Mil-STD-704 philosophies in place for decades and
> marches of to the beat of Paul's new drum . . .)
>
>>. . . eliminates false trips. Eliminating the Crow bar eliminated the hi
>>current and its side affects (see below). If used, the proper "B" lead
>>contactor will prevent alternator damage often caused by the improperly
>>used
>>common contactor that is not designed or specified for this specific
>>application and further hindered with the incorrect application of a diode
>>across the coil against major manufacturers worked wide. In fact the
>>common
>>diode across the coil is not recommended anywhere any time by relay
>>manufacturers.
>
> Yup, I've read the papers cited here on the list . . . and it didn't
> take 5 minutes at the bench to discount their value as drivers for
> our design goals. The amazing thing was that they were published
> by big names in the industry by folks with long lists of credentials.
>
> They took lots of good data, published some neat 'scope traces and
> then drew conclusions that could have been but were not directly
> measured . . . Others have read the papers and assumed that the
> stature and authority of the authors was sufficient to broadly apply
> their suppositions with almost religious fervor. Which underscores an
> observation I made years ago . . . just because one might have run a
> successful restaurant doesn't make them a good chef.
>
>> . . . That its very common in use does not mean its a good
>>approach, It simply means that most engineers are lazy and copy what has
>>been done in the past rather that research what is recommended so the
>>diode
>>persists even with its being the last and worst choice in a list of
>>options.
>
> You betcha. Did YOU bother to repeat their experiments and deduce
> for yourself the effects of diode-across-the-coil as we used it?
> This begs the question as to who is lazy here and who worships at
> the altars of Tyco-Amp, P&B, etc.
>
>
>>IN conclusion the test results showed that much of the alternator failures
>>were the direct result of the OVP design and associated contactor. Its not
>>known if poor alternator regulators were a factor but even good ones are
>>very likely to be damaged by the current design contactor used. Its clear
>>that the contactor used has a very high potential of regulator damage and
>>when coupled with a false trip prone (in some as yet defined aircraft
>>wiring
>>or operations) is the root cause.
>
> Your train of thought for cause/effect is truly amazing . . . I'm going
> to save these threads for future reference. They'll be great teaching
> tools.
>
>
>>Use a modern non-crowbar OVP design and a contactor designed for the
>>application resolved most of the problem. Its not possible to ignore the
>>likely hood of lesser quality regulators in rebuilt alternators so only
>>new
>>alternators should be used.
>>
>>With the demonstrated extremely high reliability of the ND brand of
>>internally regulated alternators is very questionable that there is a need
>>for more that having the OVP simply remove the voltage to "I" lead (the
>>field control lead) that shuts down the alternator. I have been unable to
>>find any repair shop that has ever heard of an ND alternator having
>>uncontrolled runaway failure. No output or hi output that is still
>>controllable with the "I" lead. Prop bolts or crank shafts are more likely
>>to fail and yes I have a report of a light twin having both engines prop
>>bolts failing.
>
> Okay, if I republish Z-24 then all I need to do is upgrade the
> contactor, recommend Eric's latest and greatest OVP product, and
> add a transorb (also Eric's product?). And finally, limit
> recommendations
> to brand new ND alternators? If Eric's OVP is in place is a builder
> on shaky ground by NOT using a new alternator . . . or even an ND
> product? Can you articulate the new design goals in the form of a white
> paper (the new Bible) that leads other designers down the path to
> Nirvana
> along with guidance as to the nature and magnitude of conditions to
> expect?
> (No, don't answer that. Let's go ahead and accept this as your "last
> word")
>
>>Now for the hi current related problems.
>>
>>In an steel tube reinforced cockpit like the Glastar (or other production
>>aircraft) its been proven that even the normal bus loads can magnetize the
>>tube structure and cause compass errors of as high as 30 degrees. I
>>previously referenced a manufacturers mandatory service bulletin that
>>addressed this issue and also discussed with a owner of that type aircraft
>>that had it happen to him. He is highly educated and a long time IA. The
>>compass in question was a suspended well above the affected tubes
>>
>>This tells me that even 50 amp buss circuits need special wire routing and
>>forget the 100+++ current transients from a crow bar.
>>
>>This alone says if you have a steel tubular cabin be careful and forget a
>>crow bar approach.
>
> This was the great and evil "side effect"? Gee Paul, wouldn't
> it be a good thing to simply NOT run high currents through the
> structure? Cranking the engine runs far more current (with higher
> inrushes) than a crowbar event will ever generate. The starter
> event happens every flight-cycle. The crowbar event is much smaller
> and may never happen.
>
> It's apparent to me that your primary driver in this exchange
> has been a vendetta against one who would have the audacity to
> question your autocracy in the non-dissemination of information
> combined with loads of un-substantiated advice. I don't believe
> this discussion had anything to do with science, the art of
> building reliable systems or the enthusiastic exchange of
> simple-ideas for which good teachers are noted.
>
>
>>In any event this is my last word on either subject even if the misquoting
>>etc continues.
>
> I have not snipped anything from your post so I cannot be accused
> of any mis-quotation. It's obvious that you have no appreciation
> for what it means to be a teacher or a responsible member of
> an engineering community. Since you failed to substantiate any of
> your allegations with data and cannot or will not answer any simple
> direct question, I must conclude that this being your "last word"
> on the matter is no loss to the OBAM aviation community. I look
> forward to spending time on more fruitful and honorable endeavors.
>
> As soon as I have time and access to the equipment, I'll repeat the
> tests you claim to have conducted and publish the results here and
> on my website. Please ignore them . . . there are plenty of sharp
> heads on the list who will help me refine my studies from which
> well considered design goals can be crafted and satisfied.
>
> I wish you well in your new job.
>
> Bob . . .
>
>
>
Message 8
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| Subject: | Re: FW: Splice 6AWG Wire |
--> AeroElectric-List message posted by: KITFOXZ@aol.com
That's a great idea about using monel or stainless to hold things together
for soldering, Bob!
Another idea I had forgotten about but have used at one time or another over
the years is to strip the wire ends and just shove them into a short piece
of common soft copper pipe and then sweat solder. Shield with heat shrink or
wrap with your choice of insulator material.
You could ping the pipe first or crimp it but, I think the strength of the
copper pipe would be compromised. If the I.D. of the pipe and the O.D. of the
wire are a perfect fit for each other, the plain old sweated solder joint is
superb in my book!
We are talking about a joint that is in the middle of a large diameter wire
and not at a terminal connection point that may have to withstand mechanical
loads. I don't like to use crimp connectors of any kind on large wires
unless you are sure to use the correct crimping tool and terminal.
Call me a priss but, I am concerned about the mechanical strength of large
crimped joints alone and prefer to solder them along with the crimped joint.
I have seen many crimped terminals work loose on large wires due to the
relative motion they may have to endure.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
Message 9
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| Subject: | Re: RE load dump from a novice point of view |
--> AeroElectric-List message posted by: "Frank Stringham" <fstringham@hotmail.com>
Paul and Bob
And I thought the RV7a groups primer / slider vs tip up / tail dragger vs
nose roller wars were rough.
Facts vs opinions ......... Facts can be demonstrated with accuracy and
replicated by others with precision and similar accuracy on each trial. And
as we all know opinions are like noses and other boby parts , every body's
got them........plus they can usually never be replicated to any degree of
accuracy and precision Even by the most knowledgeable, practiced, and
skilled scientist / builder
My "opinion" is that the size ($$$$$$) of the company nor the degrees of
it's scientist opinions trump the facts of the little guys tried and true
facts tested by both time in use and bench mark reality.
Man, this electronic stuff is just coming in to view for me as I approach
the wiring of my 7A. It is a whole new world to which this old retired
chemistry teacher is trying to learn the language, accepted procedures, and
tools needed to do the work. Bob thanks for the book of knowledge you have
written, updated, and so generously give no cost updates and email
instructions to those of us that are electronically challenged. Paul thanks
for your knowlegeable input that questions, prods, and tests the notions of
what is generally accepted by we electronically challenged plane builder.
With that said I am back to my "Z" diagrams preparing for the wiring of the
RV7A I am building.
Frank @ sgu and slc fuse under construction / looking forward to the
challenge of WIRING.
>From: "Paul McAllister" <paul.mcallister@qia.net>
>Reply-To: aeroelectric-list@matronics.com
>To: <aeroelectric-list@matronics.com>
>Subject: Re: AeroElectric-List: RE load dump
>Date: Sun, 18 Sep 2005 13:42:33 -0500
>
>--> AeroElectric-List message posted by: "Paul McAllister"
><paul.mcallister@qia.net>
>
>Paul,
>
>At the risk of being accused of "snipping" your email, or offering snide
>remarks, this is truly a case of an expression we use in engineering shop
>where I work (a $15 billion /year company)
>
>It goes like, "In god we trust, everyone else bring data". Please share
>it,
>many of us may learn something new.
>
>With that said, this has been a truly enlightening discussion and the
>debate
>has taught me a lot (not only about engineering)
>
>Regards, Paul
>
> > --> AeroElectric-List message posted by: "Paul Messinger"
> > <paulm@olypen.com>
> >
> > I consider the entire subject (crow bar currents) closed. I feel no need
> > to
> > continue based on your statements as its simply not worth my time to
> > reply.
> > Until my comments are accepted as fact and we can get past that and deal
> > with the real issues the ridicule of my test results clearly says it was
>a
> > mistake to ever start this in the beginning. Further the snide remarks
> > from
> > others does not help clear the air.
> >
>
>
Message 10
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0.15 HTML_TEXT_AFTER_BODY BODY: HTML contains text after BODY close tag
--> AeroElectric-List message posted by: "LarryRobertHelming" <lhelming@sigecom.net>
>--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
>
>I consider the entire subject (crow bar currents) closed. I feel no need to
>continue based on your statements as its simply not worth my time to reply.
>Until my comments are accepted as fact and we can get past that and deal
>with the real issues the ridicule of my test results clearly says it was a
>mistake to ever start this in the beginning. Further the snide remarks from
>others does not help clear the air.
Paul with all due respect you deserve, you need some stretched thinking imho.
I think not ridicule, I think we want details to support that gives proof to your
comments. Simple...but you reject that!!
Please take some time off and talk with someone about your position, the other
position, AND your reluctance to give just one inch to anyone. You sound like
a little kid pouting to get his way..... You have proved nothing but your arrogance
and distain for Bob's expertise and respect for everyone's time who reads
this list. You thumb us all by your actions. Your reluctance and defiance
says something -- but I just know I think it is strange that you are not willing
to be cooperative in the least bit with anyone it seems. And you consider
remarks like mine snide. Please talk with someone before this gets worse. Best
wishes Paul.
Indiana Larry
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
" Happiness: like a butterfly, when pursued,
is always beyond our grasp, but which,
if one sits quietly, may light upon you."
Nathaniel Hawthorne
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Message 11
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| Subject: | Re: FW: Splice 6AWG Wire |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 04:48 PM 9/18/2005 -0400, you wrote:
>--> AeroElectric-List message posted by: KITFOXZ@aol.com
>
>That's a great idea about using monel or stainless to hold things together
>for soldering, Bob!
>
>Another idea I had forgotten about but have used at one time or another over
>the years is to strip the wire ends and just shove them into a short piece
>of common soft copper pipe and then sweat solder. Shield with heat
>shrink or
>wrap with your choice of insulator material.
>
>You could ping the pipe first or crimp it but, I think the strength of the
>copper pipe would be compromised. If the I.D. of the pipe and the O.D.
>of the
>wire are a perfect fit for each other, the plain old sweated solder joint is
>superb in my book!
>
>We are talking about a joint that is in the middle of a large diameter wire
>and not at a terminal connection point that may have to withstand mechanical
>loads. I don't like to use crimp connectors of any kind on large wires
>unless you are sure to use the correct crimping tool and terminal.
>
>Call me a priss but, I am concerned about the mechanical strength of large
>crimped joints alone and prefer to solder them along with the
>crimped joint.
>I have seen many crimped terminals work loose on large wires due to the
>relative motion they may have to endure.
There's a certain attractiveness to the tube-over-joint method. Sure
comes out slick looking on the outside when you're done. But consider
that the design goal is to maximize the surface area of strands that
are in close proximity to strands of the other wire and minimize the
volume of solder needed to fill the inter-strand voids. Next, we'd
like to maximize the solder's ability to provide mechanical support.
Both goals are advanced when you interleave the strands, bind them
tightly and THEN use solder to secure the joint.
The example you cited about copper pipe is excellent. If one examines
the gap between inner and outer walls of copper components to be joined,
it is exceedingly small. So small that one must be careful not to
bend the pipes out-of-round and cut ends must be carefully deburred
or you cannot assemble the dry joint. Then, when the properly heated
and fluxed joint flows, there's a large interfacing surface area
in spite of the fact that very little solder is needed to fill the
void.
Crimped joints are just as strong as soldered joints when properly
executed. When you have the proper materials and tools, execution is
a no-brainer. But lacking those resources, solder is an excellent
joining technique that is in no way inferior to a crimped joint
when you UNDERSTAND and achieve the best that solder is capable
of doing for you.
Bob . . .
Message 12
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 09:32 PM 9/18/2005 +0100, you wrote:
>--> AeroElectric-List message posted by: "Steve Hunt"
><stephen.hunt19@btinternet.com>
>Hi Bob
>Wow! I just joined............ I want to ask you if you think it OK for me
>to proceed with my effort at hooking up my Vans 60 A int regulated alt as
>follows. (I am no engineer, have little electrical knowledge)I have a B& C
>cont rated contactor on the B lead which is switched by the second throw of
>my Batt/Alt sw (2-10). I have, as yet no crowbar. I intend to always start
>with alt switched off and stopping eng with alt switched on. I dont know how
>I got here as I have the lost the thread of the latest advice and am feeling
>confused. The loom all laid up, panel cut. I was ready to go and then got
>hopelessly lost trying to follow this. Whilst it may not be the best
>solution Bob, will this work?
Absolutely! I would not discourage anyone from proceeding with
any plans in place to get their projects finished and flying.
Risks are small irrespective of any hazard one might wish to
address in their design. Further, once rational solutions to
the questions before us are derived, they're easy to add later.
Don't let the floobydust flying around slow you down or worry
you in the least.
It's the job of folks who understand the issues and share
a common interest in offering high value solutions that
will happily filter the floobydust for nuggets of good data
and make the results available to all along with details
as to how the decisions were made.
>Thanks in anticipation,Steve
You're most welcome.
Bob . . .
Message 13
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| Subject: | Re: RE load dump from a novice point of view |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 03:17 PM 9/18/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: "Frank Stringham"
><fstringham@hotmail.com>
>
<snip>
>Man, this electronic stuff is just coming in to view for me as I approach
>the wiring of my 7A. It is a whole new world to which this old retired
>chemistry teacher is trying to learn the language, accepted procedures, and
>tools needed to do the work. Bob thanks for the book of knowledge you have
>written, updated, and so generously give no cost updates and email
>instructions to those of us that are electronically challenged.
You're most welcome. As a scientist, you'll appreciate my pedantic
quest for underlying simple-ideas that support our design decisions.
Electronics is no more difficult than chemistry. Just a different
vernacular and a different box of Tinker-Toys . . . but the fundamental
principals are the same and easy to grasp if you have dedicated teachers
to help. On the AeroElectric-List, you're in good hands and we'll do
earn your trust and respect as fellow scientists.
Bob . . .
Message 14
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| Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: Tom Velvick <tomvelvick@cox.net>
Hi Bob,
I think this is the post from 04/02/2005 that Paul is referring to.
Regards,
Tom Velvick
>>Bob ran a test of the OVP using a CB with a resistance of 0.36 ohms. He used
#20 wire, he used a 2 year old battery no longer suitable for flight. He
ended up with 135 amps current thru the CB and 15 milliseconds to open.
I ran a test of a my built-up version of the same OVP module. My CB a 7277
(Bob used a very similar 7274) was measures not at 0.36 ohms (the max
specification resistance but 0.010 ohms.
I used #4 (3 ft total and #6 wire 4 ft total and all bolted brass or copper
connections) (vs. Bob's #20 wire). My battery was dual PC-625 rated at 3.5
milliohms (Bob used a Panasonic rated new at 13 milliohms and it was not
new) My battery setup has a 3600 amp short circuit rating. My open time was
50-70 milliseconds. Higher current and longer times?? Seems not to make
sense but that comes later.
That I got 400 amps and Bob got 135 amps is reasonable and both of our tests
are reasonable system tests. My test was a near exact example of my real
acft.<<
Message 15
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--> AeroElectric-List message posted by: N1deltawhiskey@aol.com
Bob,
Lost your response to the message below, but thanks for the offer to replace
the unit if damaged. Too bad more providers of equipment are not so willing
to stand by what they dump on unsuspecting people.
Anyway, I reinstalled the unit and it is working fine as far as I can tell.
Regards,
Doug Windhorn
----------
Bob,
Thanks. All of my wiring gear is at the hanger, so won't be doing this until
next weekend.
But in reading your response, I may have identified a/the problem. On the
drawing I have, I interpreted the ground pin (-) as 5 rather than 6, and that is
how I wired it. After looking more closely at the drawing, the 5's are
different from the 6's - field of view (mentally) just wasn't broad enough.
Think any damage was done with pin 5 grounded? I guess I will find out when
I rewire and test it.
Regards, Doug
In a message dated 11-Sep-05 23:55:18 Pacific Standard Time,
nuckollsr@cox.net writes:
>Bob,
>
>I have your AEC9005-101 LVW. I am not using the battery management feature,
>so have just connected the fused positive and ground wires along with the LED
>wires to the unit.
>
>I have not seen this unit work as expected. I verified continuity of the
>positive and ground wiring connections (overlooked checking the LED
>connections
>to be sure they were right today), but found no apparent issues with the
>wiring.
>
>I thought I would try something else, connection the positive and ground
>directly to a battery. It still did not work, but shortly thereafter I
>smelled hot
>insulation. I touched the wires leading to the LVM and didn't bother to hang
>on - just disconnected the battery real quick.
>
>Any idea of what the problem might be? How can I get this working properly?
>Could incorrectly wired LED wires cause this problem? (I will check those
>next
>time at the hanger.) Is it a defective unit?
I've never had one returned. They're easy to check. Get a
9-pin d-sub female connector from Radio Shack or other
handy source. Short pins 2 and 3 together. Put leadwires
on pins 4 (+in) and 6 (ground). Plug your LVW/ABMM
module into this connector and then connect the pin 4
wire to (+) on your car battery and pin 6 wire to (-)
or ground. Engine should not be running for this test.
If the module is okay, it the LED on the module will be
flashing. Start the engine and repeat the test. The
LED should not be flashing.
Bob . . .
Message 16
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| Subject: | Re: RE load dump |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
On Sun, 18 Sep 2005 08:16:59 -0700, Paul Messinger <paulm@olypen.com>
wrote:
> I consider the entire subject (crow bar currents) closed. I feel no
> need to continue based on your statements as its simply > not worth my
> time to reply ...
Paul -
Yet, you continued picking at the issue for another several paragraphs!! I
thought this issue was closed when you regained control of your social
feedback loop - evidenced by your unusually long absence from this forum.
Welcome back. In your case, I choose not to use the delete key because I
am interested and amused at seeing how, with every posting, you so
haplessly and consistently destroy your credibility in the area of
electrical engineering and electronics. I agree with Indiana Larry: you
really need to talk with someone.
Do not archive
John Schroeder
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