Today's Message Index:
----------------------
1. 05:03 AM - Re: Re: Breaker Interrupt Rating (LarryRobertHelming)
2. 06:21 AM - Re: Re: Breaker Interrupt Rating (Robert L. Nuckolls, III)
3. 06:21 AM - Re: Re: Breaker Interrupt Rating (Robert L. Nuckolls, III)
4. 06:49 AM - Re: Re: Breaker Interrupt Rating (RV Builder (Michael Sausen))
5. 07:25 AM - Re: degaussing (demagnetizing) my roll bar (Eric M. Jones)
6. 07:42 AM - Re: Breaker Interrupt Rating (Eric M. Jones)
7. 08:17 AM - Re: Breaker Interrupt Rating (Ernest Christley)
8. 08:52 AM - Re: Tire valve extension (Wayne Berg)
9. 09:41 AM - Re: Re: Breaker Interrupt Rating (Terry Watson)
10. 10:01 AM - Re: Re: degaussing (demagnetizing) (GMC)
11. 10:35 AM - Re: Breaker Interrupt Rating (Eric M. Jones)
12. 11:12 AM - Re: Re: Breaker Interrupt Rating (Mickey Coggins)
13. 11:16 AM - Re: Re: degaussing (demagnetizing) my roll bar (Mickey Coggins)
14. 12:27 PM - Re: degaussing (demagnetizing) my roll bar (Eric M. Jones)
15. 02:46 PM - magneto timing buzz box (Dan Checkoway)
16. 04:02 PM - Re: magneto timing buzz box (Robert L. Nuckolls, III)
17. 04:15 PM - Re: magneto timing buzz box (D Wysong)
18. 08:41 PM - Re: Re: Breaker Interrupt Rating (Charlie England)
19. 09:02 PM - Re: magneto timing buzz box (John Schroeder)
20. 09:54 PM - Re: Breaker Interrupt Rating (Eric M. Jones)
Message 1
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Subject: | Re: RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "LarryRobertHelming" <lhelming@sigecom.net>
Bob: might I suggest you should use, for these that make claims and fail to
back them up with their own testing as you have requested time and time
again without response, the DELETE key. In other words just ignore them.
Or better still, let them run their own bulletin board and ban them from
posting on aeroelectric. They are obviously wanting to introduce and sell
new products but should not need to throw insults and challenges without
supporting scientific data to back it up. I have bought some stuff in the
past when I thought I could see the merit. ( I bought Eric's Diode because
it saves some current and my 35 amp alternator is stretched when landing
with landing lights and strobes on while at low rpms. ) do not archive
Indiana Larry, RV7 Tip Up SunSeeker -- wired without Transorbs or an
avionic's buss and it has not self destructed after 61 hours.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
" Happiness: like a butterfly, when pursued,
is always beyond our grasp, but which,
if one sits quietly, may light upon you."
Nathaniel Hawthorne
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
----- Original Message -----
snip
> Years later, some have decided to play the specs game when
> in fact, they were blatantly guilty of mis-interpreting and/or
> ignoring component specs just as I've been accused of doing. See:
>
> http://aeroelectric.com/articles/spike.pdf
>
> Some numbers tossed around in this thread weren't as wild as the
> 700A fault currents claimed at the beginning of the latest
> discussion started but were no more accurate.
>
> You guys are very long on throwing interpretation of specs around
> and short on both hard data and experience. Please, sell all the
> series shut down devices you wish . . . shucks, if you want
> to peddle ov RELAYS . . . those are fine too. But if the only
> way you can sell your products/ideas is to claim my products/
> ideas are deficient and use concocted numbers and claims to
> support it, it's a sad day for the CONSUMERS of devices who
> must make decisions on data no better than that offered by a
> commercial for laundry soap.
>
> The challenge still stands. Take any breaker you like and
> throw it across a 12v battery as many times as you like and
> tell me how many times you have to whack it to trash it.
> I've not been able to do it on my bench, maybe your's is
> uglier than mine. I've done all the testing I'm going
> to do to defend myself against the indefensible . . . the
> interminable string of allegations. It's time for you guys
> to put up or shut up. Show me the smoke . . .
>
> By the way Eric. I've been trying to identify a connector/tool
> combination that works well with that sample of coax I got
> from you in Plymouth. It may be great coax but I found it
> very user-unfriendly to work with. If you're going to recommend
> and/or sell it, I'll suggest you recommend/supply tools and
> connectors to mate with it. A step-by-step instruction sheet
> to aid the builder in getting it right by the second or third
> try would be good too . . .
>
> Bob . . .
Message 2
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Subject: | Re: RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 07:02 AM 9/16/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "LarryRobertHelming"
><lhelming@sigecom.net>
>
>Bob: might I suggest you should use, for these that make claims and fail to
>back them up with their own testing as you have requested time and time
>again without response, the DELETE key.
<snip>
It would be the EASIEST thing to do . . . But I cannot ignore echoes
of some words by an intellectual super-hero of mine who once offered:
"Perhaps the sentiments contained in the following pages,
are not yet sufficiently fashionable to procure them general
favor; a long habit of not thinking a thing wrong, gives
it a superficial appearance of being right, and raises at
first a formidable outcry in defence of custom. But the tumult
soon subsides. Time makes more converts than reason."
Common Sense by Thomas Paine 1776
The topic of his missive was to discuss the simple ideas of good
government and the rights of individuals to live without fear of
force or fraud against person or property (liberty for short). But
the paragraph is a simple-idea unto itself. If you do not consistently
and calmly defend a simple-idea by which you operate, then after
a time a LACK OF DEFENSE is easily misconstrued to be a demonstration
of weakness or falsity of the idea. Many folks in both government and
science depend on the age old idea of simply wearing the opposition down
with tenacity and the ease with which allegations can be tossed . . .
one can conduct an effective offense even without UNDERSTANDING of the
ideas under discussion!
I heartily encourage folks who find these conversations troubling,
boring, or useless to use the DELETE key as their personal feelings
dictate. But if I'm to stay true to my craft, I cannot allow time
to elevate bad science to the level of believable simply because I'm
weary of defending good science. Nor do I belive it's a good idea to
"take the discussions off-list" . . . our system of justice used to
be founded on a judgement by our peers. One can acquire neither
justice as an individual nor effect the propagation of good science
by conducing the discussions in the dark.
Thank you for your concerns my friend but as long as I can muster
the energy, I'm not the one who is in need of rescue.
Bob . . .
Message 3
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Subject: | Re: RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 07:49 AM 9/16/2005 +0200, you wrote:
>--> AeroElectric-List message posted by: Mickey Coggins
><mick-matronics@rv8.ch>
>
> > By the way Eric. I've been trying to identify a connector/tool
> > combination that works well with that sample of coax I got
> > from you in Plymouth. It may be great coax but I found it
> > very user-unfriendly to work with. If you're going to recommend
> > and/or sell it, I'll suggest you recommend/supply tools and
> > connectors to mate with it. A step-by-step instruction sheet
> > to aid the builder in getting it right by the second or third
> > try would be good too . . .
>
>I used this wire too. Since it was the first time I've ever
>done anything with coax, I just thought working with coax was
>hard. Now I feel a bit better! I got the stuff cut, trimmed,
>and crimped, but I don't have 100% confidence in the quality
>of my work. I was planning on finding out how good it works
>on the first flight.
What tool and connectors did you use? This coax is smaller
than RG400/142 and larger than RG174. I have connectors that
mate nicely with both sizes and neither was suited to this
task. There might be an intermediate sized connector available
but they're not in common distribution by any of my favorite
suppliers.
Bob . . .
Message 4
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "RV Builder (Michael Sausen)" <rvbuilder@sausen.net>
Bob: might I suggest you should use, for these that make claims and fail to back
them up with their own testing as you have requested time and time again without
response, the DELETE key. In other words just ignore them.
<snip>
No kidding
Or better still, let them run their own bulletin board and ban them from posting
on aeroelectric.
<snip>
Umm, I believe this is Matt's list, not Bob's. Not trying to split hairs
but this is a public forum and people should be allowed to disagree. I've
said it before, I respect Bob and feel he adds more to the aviation community
than 95% of the rest of us but I do still like to hear what other people have
to say. If they don't have data to back it up I like to think I'm intelligent
enough to take that into account when evaluating options. I have, on a regular
basis, eschewed technologies which show much greater benefits in favor of proven
technologies. Of course this list does ware the name of Bob's book and
therefore we should expect him to defend his theories and methods with vigor.
;-)
Let's not turn this into another pi$$ing contest on who's correct or who's
technology is better. Just because something is new and/or unproven doesn't
make it wrong just like old/proven technology doesn't automatically need to
be replaced with the next new thing comes along. Use your own judgment.
Michael Sausen
-10 #352
Do not archive
FWIW
My 2 cents
YMMV
IMHO
Yada yada yada
Message 5
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Subject: | Re: degaussing (demagnetizing) my roll bar |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: Mickey Coggins
<mick-matronics@rv8.ch>
>I'm not really sure how it got magnetized, but it came this
>way from Van's. Seems to be a common problem. I checked it
>by putting a simple orienteering compass near it. It swings
>the needle when about a foot away. My panel mounted compass
>will be less than a foot away. Thanks for the hints. Best regards, Mickey
Hi Mickey,
If you take your compass and examine a can of beans from your pantry, you
will find it is magnetized. Almost every piece of ferrous metal slowly
drifts into the magnetic state of its environment. Using the 4130 metal
airframe for a ground also causes problems, since currents through the metal
cause magnetization. Some alloys are worse than others. Aircraft tubing is
almost all 4130 so choosing another alloy is not practical.
Eliminating magnetization is a process of scrambling the domains by
alternating the magnetic field while slowly reducing the field to zero. A
spool of wire, and a variable output transformer (variac) are the tools you
need; but how much and where is your individual experiment.
> Is your fuselage located such that the roll bar is close to (underneath)
> fluorescent lights. My roll bar & other parts became magnetized sitting
> under a four tube fluorescent light fixture in garage. Magnetism bled
> off after aircraft was moved to hangar.
>
> George in Langley BC
George,
I think it is more likely that moving the aircraft 90 degrees was the
solution. But just wait a few months to see what happened.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Nothing is too wonderful to be true."
James Clerk Maxwell, discoverer of electromagnetism
"Too much of a good thing can be wonderful."
Mae West, discoverer of personal magnetism
Message 6
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Matt--
> You might say that calibration and operating performance applies to the
> behavior during only one firey interrupt. However, the calibration curve
> only goes to 1000x the rating.
Please look again. That's 10X the rating or 1000%. Bob claims the curves can be
extended. This is a fundamental disagreement.
Another problem is how the device will operate at 12V when the trip times are for
28V. There is an important alloy difference in contacts good for 12 and 28
volts. I don't know, but I can imagine a scenario where the contacts would weld
without sufficient heat to cause the bimetal strip to flex enough. At any rate,
it is wrong to think a device specified for 28V will "work fine" at 12-14V.
It is also wrong to think that AC applications are more rigorous than DC.
Paul Messinger's tests show that the discharge can be far greater than the CB is
spec'd for. This devolved into an argument about battery resistances, but I
believe Paul (since I am somewhat party to his testing).
> Datasheets exist to cover the backsides of the producer, but also to
> provide useful information about how to apply a product correctly.
> If a breaker isn't reusable after a real-world hard fault, that's one of the
industry's best-kept dirty little secrets.
CBs fail all the time, but less so when they are properly located in real systems.
In the worst case fault a CB only has to work three times to be approved for
that current. "Crowbar" usage is a special application. There are plenty of
guys using two motorcycle batteries in parallel, or newer batteries with phenomenal
cranking capabilities. I believe Paul's 400 Amp result would be easy to
get, and the CB is not correct for the application. Adding a resistor seems easy
but requires a pulse rated part.
You can't test the crowbar design into a good design.
> None the less, maybe you're right, and Rutan is right. Minimum specs end up
being performance ceilings.
Agreed. But consider that in a mature product the performance tolerance is so small
that it does not encourage improvement in the product. This is the best that
can be done in a particular design. And it's a good thing, not a bad thing.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Everything you've learned in school as "obvious" becomes
less and less obvious as you begin to study the universe.
For example, there are no solids in the universe. There's
not even a suggestion of a solid. There are no absolute con-
tinuums. There are no surfaces. There are no straight lines."
- R. Buckminster Fuller
Message 7
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: Ernest Christley <echristley@nc.rr.com>
Eric M. Jones wrote:
>Clever engineers those Klixon guys. Or maybe not.... Interrupting capacity
>per UL1077/IEC934/EN60934 PC1 is defined as the maximum current that a
>circuit breaker must interrupt-just one time-without causing a safely
>hazard. KaaPowwwww......Operating a circuit breaker outside its published
>ratings is a bad idea. Crowbarring cicuit breakers was an historic method
>used in the olden days. Good thing that better methods like Linear
>Non-crowbar OVP's were invented.
Eric, it is my understanding, and the understanding of everyone I've ever dealt
with, that the purpose of a circuit breaker is to break the circuit when something
gets shorted. The only failure mode I've ever heard of is that the breaker
trips easier as it gets old/wears out/is abused. In fact, when I worked as
an electrician's helper in high school, the guy carried around an extra pair
of old cutter for the express purpose of cutting through a pair of wires to cause
the breaker to trip (so he'd know without a doubt that he was turning off
the correct breaker to kill a circuit). That is, he would routinely throw a
dead short to trip the breaker.
I cannot fathom what 'safely hazard' can be caused by tripping a breaker. THAT
IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a resettable
circuit interrupton. The worst case scenario is that the breaker want
stay closed if you ever hit it too hard. How long would D-Square stay in business
if they advertised a breaker that "worked most of the time, but would sometimes
fail with a dead short"? They would be laughed out of any industry that
had anything to do with electricity.
If the whole point is to open the circuit after something bad happens...and we're
not going to reset it ('cause we have enough battery reserve to get where we
were going, and we'll troubleshoot there), then what's wrong with it staying
open after something bad happens? Could you please explain to the casual reader
what these safety hazards are? Any example of it ever happening? Please,
don't limit yourself to aviation applications. Any anectdotal example anywhere?
--
,|"|"|, |
----===<{{(oQo)}}>===---- Dyke Delta |
o| d |o www.ernest.isa-geek.org |
Message 8
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Subject: | Re: Tire valve extension |
--> AeroElectric-List message posted by: "Wayne Berg" <wfberg@msn.com>
Thanks Gary. Exactly what I wanted.
Wayne Berg
----- Original Message -----
From: Gerry Holland
Subject: Re: AeroElectric-List: Tire valve extension
--> AeroElectric-List message posted by: Gerry Holland <gholland@gemini-resourcing.com>
> --> AeroElectric-List message posted by: "Wayne Berg" <wfberg@msn.com>
>
> Does anyone have a source for tire valve extentions that avoids having to
> remove wheel pants to inflate tires? I know I've seen the add before but have
> lost the flier.
Try:
http://www.aircraftextras.com/Valve-ext.htm
I have one here in UK from them. Works great!
Gerry Holland
gholland@gemini-resourcing.com
+44 7808 402404 (Mobile)
+44 1249 700633 (Direct)
+44 01225 436104 (Office)
+44 870 7059985 (Fax)
Gemini Resourcing Limited Hartham Park, Corsham, Wilts. SN13 0RP - UK
Main: +44 1249 700630 Fax: +44 8707 051315
Website - http://www.gemini-resourcing.com
DISCLAIMER: This message may contain privileged and confidential
information. If you think for any reason this message has been addressed in
error you must not copy or disseminate it and we would ask you to notify us
immediately by return e-mail to info@gemini-resourcing.com. Internet emails
are not necessarily secure. Gemini Resourcing Limited is registered in
England with its address at: Hartham Park, Corsham, Wilts. SN13 0RP,
England.
Regards
Gerry
Message 9
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Terry Watson" <terry@tcwatson.com>
I think this requires a little clarification. Anyone else who has been on
the list from the beginning, including Bob, please correct me if I am wrong.
Matt created the Aeroelectric list as a forum for Bob Nuckolls to field
questions from experimental airplane builders or airplane owners, and as a
general discussion list about aircraft electrical topics. Prior to having
the Aeroelectric list, Bob was monitoring many lists and trying to answer
questions on this subject. The list was in part an expression of Matt's
appreciation for the exceptional value of Bob's efforts. Bob, as the true
gentleman that he is, has never reminded anyone of that fact.
So, yes, it is Matt's list, created as a forum for Bob.
As I said, if I am wrong, please correct me.
Terry
RV-8A number 80729
Still finishing
Seattle
Umm, I believe this is Matt's list, not Bob's. Not trying to split
hairs but this is a public forum and people should be allowed to disagree.
I've said it before, I respect Bob and feel he adds more to the aviation
community than 95% of the rest of us but I do still like to hear what other
people have to say. If they don't have data to back it up I like to think
I'm intelligent enough to take that into account when evaluating options. I
have, on a regular basis, eschewed technologies which show much greater
benefits in favor of proven technologies. Of course this list does ware the
name of Bob's book and therefore we should expect him to defend his theories
and methods with vigor. ;-)
Let's not turn this into another pi$$ing contest on who's correct or
who's technology is better. Just because something is new and/or unproven
doesn't make it wrong just like old/proven technology doesn't automatically
need to be replaced with the next new thing comes along. Use your own
judgment.
Michael Sausen
-10 #352
Do not archive
FWIW
My 2 cents
YMMV
IMHO
Yada yada yada
Message 10
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Subject: | Re: degaussing (demagnetizing) |
--> AeroElectric-List message posted by: GMC <gmcnutt@shaw.ca>
Hi Eric
You could well be right. If anyone wants to check for magnetism in their
workshop try checking with your hydro utility company they often have a
meter [gausmeter ?] that you can borrow at no charge. I discovered that
my fluorescent fixtures generated significant magnetic fields.
George in Langley BC
Eric M. Jones wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>--> AeroElectric-List message posted by: Mickey Coggins
><mick-matronics@rv8.ch>
>
>
>
>>I'm not really sure how it got magnetized, but it came this
>>way from Van's. Seems to be a common problem. I checked it
>>by putting a simple orienteering compass near it. It swings
>>the needle when about a foot away. My panel mounted compass
>>will be less than a foot away. Thanks for the hints. Best regards, Mickey
>>
>>
>
>Hi Mickey,
>
>If you take your compass and examine a can of beans from your pantry, you
>will find it is magnetized. Almost every piece of ferrous metal slowly
>drifts into the magnetic state of its environment. Using the 4130 metal
>airframe for a ground also causes problems, since currents through the metal
>cause magnetization. Some alloys are worse than others. Aircraft tubing is
>almost all 4130 so choosing another alloy is not practical.
>
>Eliminating magnetization is a process of scrambling the domains by
>alternating the magnetic field while slowly reducing the field to zero. A
>spool of wire, and a variable output transformer (variac) are the tools you
>need; but how much and where is your individual experiment.
>
>
>
>>Is your fuselage located such that the roll bar is close to (underneath)
>>fluorescent lights. My roll bar & other parts became magnetized sitting
>>under a four tube fluorescent light fixture in garage. Magnetism bled
>>off after aircraft was moved to hangar.
>>
>>George in Langley BC
>>
>>
>
>George,
>
>I think it is more likely that moving the aircraft 90 degrees was the
>solution. But just wait a few months to see what happened.
>
>Regards,
>Eric M. Jones
>
>
>
Message 11
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: Ernest Christley
echristley@nc.rr.com
Ernest,
>Eric, it is my understanding, and the understanding of everyone I've ever
>dealt
>with, that the purpose of a circuit breaker is to break the circuit when
>something
>gets shorted. The only failure mode I've ever heard of is that the breaker
>trips easier as it gets old/wears out/is abused. In fact, when I worked as
>an electrician's helper in high school, the guy carried around an extra
>pair
>of old cutter for the express purpose of cutting through a pair of wires to
>cause
>the breaker to trip (so he'd know without a doubt that he was turning off
>the correct breaker to kill a circuit). That is, he would routinely throw
>a
>dead short to trip the breaker.
Cool! I met a very old electrician (everyone called him "Sparky"), who loved
to regale the young engineers by telling them how he would use his bare
fingers to determine the voltage...120, 240, and 480 VAC.
>I cannot fathom what 'safely hazard' can be caused by tripping a breaker.
>THAT
>IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a
>resettable
>circuit interrupton. The worst case scenario is that the breaker want
>stay closed if you ever hit it too hard. How long would D-Square stay in
>business
>if they advertised a breaker that "worked most of the time, but would
>sometimes
>fail with a dead short"? They would be laughed out of any industry that
>had anything to do with electricity.
>If the whole point is to open the circuit after something bad happens...and
>we're
>not going to reset it ('cause we have enough battery reserve to get where
>we
>were going, and we'll troubleshoot there), then what's wrong with it
>staying
>open after something bad happens? Could you please explain to the casual
>reader
>what these safety hazards are? Any example of it ever happening? Please,
>don't limit yourself to aviation applications. Any anectdotal example
>anywhere?
Surely.
If you Google ' Circuit Breaker Fail OR Failure' you will find the real
world situation. My experience in using hundreds of thousands of circuit
breakers or many types is that it is a far more complicated subject than
most people believe.
Safety hazards include not setting the local surroundings afire. I used to
sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B
Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first
test with a 24V battery as OV, the circuit breaker opened but failed
catastrophically. Since the OVP test setup was not a perfect reflection of
the real world, I discounted the incident, but later decided to not sell
crowbar type OVPs at all.
Paul Messinger's 400A measurement used a setup that was an exact duplicate
(wire lengths and all) of his aircraft's system. In order for a CB to be
rated as "interrupted without damage", it usually only has to do this 3X.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
Teamwork: " A lot of people doing exactly what I say."
(Marketing exec., Citrix Corp.)
Message 12
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Subject: | Re: RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
>>> By the way Eric. I've been trying to identify a connector/tool
>>> combination that works well with that sample of coax I got
>>> from you in Plymouth. It may be great coax but I found it
>>> very user-unfriendly to work with. If you're going to recommend
>>> and/or sell it, I'll suggest you recommend/supply tools and
>>> connectors to mate with it. A step-by-step instruction sheet
>>> to aid the builder in getting it right by the second or third
>>> try would be good too . . .
>>
>>I used this wire too. Since it was the first time I've ever
>>done anything with coax, I just thought working with coax was
>>hard. Now I feel a bit better! I got the stuff cut, trimmed,
>>and crimped, but I don't have 100% confidence in the quality
>>of my work. I was planning on finding out how good it works
>>on the first flight.
>
>
> What tool and connectors did you use? This coax is smaller
> than RG400/142 and larger than RG174. I have connectors that
> mate nicely with both sizes and neither was suited to this
> task. There might be an intermediate sized connector available
> but they're not in common distribution by any of my favorite
> suppliers.
I used one of these types of ratcheting crimpers:
http://www.steinair.com/images/store/panels/sat001.jpg
with this die:
http://www.steinair.com/images/store/coaxdie.jpg
I also used "standard" "RG400 & RG58" connectors:
http://www.steinair.com/images/SA1010F.jpg
I put heat shrink around the whole connector like this:
http://www.rv8.ch/article.php?story=20050110191323706
I guess if Eric chimes in and comes up with some better
hardware, I'll re-do the cables. Probably take about
20 minutes - everything's still open and easy to get
to.
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 13
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Subject: | Re: degaussing (demagnetizing) my roll bar |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
> Eliminating magnetization is a process of scrambling the domains by
> alternating the magnetic field while slowly reducing the field to zero. A
> spool of wire, and a variable output transformer (variac) are the tools you
> need; but how much and where is your individual experiment.
Hi Eric,
Thanks for the info. Do you think it's a waste of time to do this?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 14
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Subject: | Re: degaussing (demagnetizing) my roll bar |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: Mickey Coggins
<mick-matronics@rv8.ch>
> Eliminating magnetization is a process of scrambling the domains by
> alternating the magnetic field while slowly reducing the field to zero. A
> spool of wire, and a variable output transformer (variac) are the tools
> you
> need; but how much and where is your individual experiment.
>Hi Eric,
>Thanks for the info. Do you think it's a waste of time to do this? Thanks,
>Mickey
Mickey,
If it were my airplane, I'd do it once or twice if the equipment was not too
hard to find. (BTW--You do live in the world's HQ for demagnetizers. Every
watchmaker has at least one.)
Then depending on the results I'd either do it periodically; mu-metal wrap
the rollbar near the compass; get a remote compass; or just live with it.
Eric
do not archive
Message 15
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Subject: | magneto timing buzz box |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
I've scoured the archives and haven't found anything definitive. I want to
roll my own "buzz box" for timing my magneto. This can't be too complicated
(although it's over my head, else I'd already have done it).
Does anybody have a buzz box circuit that works?
)_( Dan
RV-7 N714D
http://www.rvproject.com
Message 16
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Subject: | Re: magneto timing buzz box |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 02:44 PM 9/16/2005 -0700, you wrote:
>--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
>
>I've scoured the archives and haven't found anything definitive. I want to
>roll my own "buzz box" for timing my magneto. This can't be too complicated
>(although it's over my head, else I'd already have done it).
>
>Does anybody have a buzz box circuit that works?
I had a schematic for one (I think out of a Sport Aviation
article) but I can't put my hands on it. The problem with using
an ohmmeter to detect point opening arises from the fact that
points in a mag are paralleled with a very low resistance
primary winding on the magneto core. It looks like a dead
short to most ohmmeters and therefore, difficult to detect when
the points open. The "buzz box" used a buzzer to generate
a relatively high frequency AC signal that could take advantage
of the primary winding's apparent rise in resistance as the
excitation frequency went up . . . much easier to tell when
the dead-short points opened up.
I'm wondering if a milliohmmeter adapter I showed at:
http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf
wouldn't detect the points opening in a magneto . . .
I'll keep an eye out for the article I copied and post
it if I find it.
Bob . . .
Message 17
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Subject: | Re: magneto timing buzz box |
--> AeroElectric-List message posted by: D Wysong <hdwysong@gmail.com>
Is it this one, Bob?
http://www.rst-engr.com/kitplanes/KP9910/KP9910.htm
D
--------------------------
Robert L. Nuckolls, III wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
>
> At 02:44 PM 9/16/2005 -0700, you wrote:
>
>
>>--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
>>
>>I've scoured the archives and haven't found anything definitive. I want to
>>roll my own "buzz box" for timing my magneto. This can't be too complicated
>>(although it's over my head, else I'd already have done it).
>>
>>Does anybody have a buzz box circuit that works?
>
>
> I had a schematic for one (I think out of a Sport Aviation
> article) but I can't put my hands on it. The problem with using
> an ohmmeter to detect point opening arises from the fact that
> points in a mag are paralleled with a very low resistance
> primary winding on the magneto core. It looks like a dead
> short to most ohmmeters and therefore, difficult to detect when
> the points open. The "buzz box" used a buzzer to generate
> a relatively high frequency AC signal that could take advantage
> of the primary winding's apparent rise in resistance as the
> excitation frequency went up . . . much easier to tell when
> the dead-short points opened up.
>
> I'm wondering if a milliohmmeter adapter I showed at:
>
> http://aeroelectric.com/articles/LowOhmsAdapter_3.pdf
>
> wouldn't detect the points opening in a magneto . . .
>
> I'll keep an eye out for the article I copied and post
> it if I find it.
>
> Bob . . .
>
>
>
>
>
>
>
Message 18
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Subject: | Re: RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
Eric M. Jones wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>--> AeroElectric-List message posted by: Ernest Christley
>echristley@nc.rr.com
>
>Ernest,
>
>
>
>>Eric, it is my understanding, and the understanding of everyone I've ever
>>dealt
>>with, that the purpose of a circuit breaker is to break the circuit when
>>something
>>gets shorted. The only failure mode I've ever heard of is that the breaker
>>trips easier as it gets old/wears out/is abused. In fact, when I worked as
>>an electrician's helper in high school, the guy carried around an extra
>>pair
>>of old cutter for the express purpose of cutting through a pair of wires to
>>cause
>>the breaker to trip (so he'd know without a doubt that he was turning off
>>the correct breaker to kill a circuit). That is, he would routinely throw
>>a
>>dead short to trip the breaker.
>>
>>
>
>Cool! I met a very old electrician (everyone called him "Sparky"), who loved
>to regale the young engineers by telling them how he would use his bare
>fingers to determine the voltage...120, 240, and 480 VAC.
>
>
>
>>I cannot fathom what 'safely hazard' can be caused by tripping a breaker.
>>THAT
>>IS WHAT THEY ARE THERE FOR. Their whole purpose for existing is to be a
>>resettable
>>circuit interrupton. The worst case scenario is that the breaker want
>>stay closed if you ever hit it too hard. How long would D-Square stay in
>>business
>>if they advertised a breaker that "worked most of the time, but would
>>sometimes
>>fail with a dead short"? They would be laughed out of any industry that
>>had anything to do with electricity.
>>
>>
>
>
>
>>If the whole point is to open the circuit after something bad happens...and
>>we're
>>not going to reset it ('cause we have enough battery reserve to get where
>>we
>>were going, and we'll troubleshoot there), then what's wrong with it
>>staying
>>open after something bad happens? Could you please explain to the casual
>>reader
>>what these safety hazards are? Any example of it ever happening? Please,
>>don't limit yourself to aviation applications. Any anectdotal example
>>anywhere?
>>
>>
>
>Surely.
>
>If you Google ' Circuit Breaker Fail OR Failure' you will find the real
>world situation. My experience in using hundreds of thousands of circuit
>breakers or many types is that it is a far more complicated subject than
>most people believe.
>
>Safety hazards include not setting the local surroundings afire. I used to
>sell crowbar OVPs similar to Bob's. Part of my test fixture was a Tyco P&B
>Series W28 10A Thermal Circuit Breaker purchased from Digikey. On the first
>test with a 24V battery as OV, the circuit breaker opened but failed
>catastrophically. Since the OVP test setup was not a perfect reflection of
>the real world, I discounted the incident, but later decided to not sell
>crowbar type OVPs at all.
>
>Paul Messinger's 400A measurement used a setup that was an exact duplicate
>(wire lengths and all) of his aircraft's system. In order for a CB to be
>rated as "interrupted without damage", it usually only has to do this 3X.
>
>Regards,
>Eric M. Jones
>www.PerihelionDesign.com
>113 Brentwood Drive
>Southbridge MA 01550-2705
>(508) 764-2072
>
You have personal experience using hundreds of thousands of circuit
breakers? You must have had an exceedingly long and/or prolific career.
If we limit the count to 200,000, that works out to around 15 per work
day over a 50 year career if you don't take any vacations. Were they all
aircraft style c/b's? ;-)
Charlie
Message 19
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Subject: | Re: magneto timing buzz box |
--> AeroElectric-List message posted by: "John Schroeder" <jschroeder@perigee.net>
Kitplanes had an article about this a couple of yerars ago.
>
> Does anybody have a buzz box circuit that works?
>
> )_( Dan
> RV-7 N714D
> http://www.rvproject.com
Message 20
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Subject: | RE: Breaker Interrupt Rating |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: Charlie England
ceengland@bellsouth.net
>You have personal experience using hundreds of thousands of circuit
>breakers? You must have had an exceedingly long and/or prolific career.
>If we limit the count to 200,000, that works out to around 15 per work
>day over a 50 year career if you don't take any vacations. Were they all
>aircraft style c/b's? ;-)
Charlie,
Sure.
I was chief engineer for 28 years at a medical instrument company that made
gizmos in boxes to be used in surgery, before that I ran my own similar
company. The medical business preferred circuit breakers because finding a
replacement fuse in the middle of an operation was risky business--so nearly
everything we made had a circuit breaker in it. Some had more than one.
Twenty different kinds probably.
Obviously I didn't install many myself, but supervised what was happening
and had to obtain a basketful of worldwide electrical approvals for most
devices that used them. Let me tell you....Brazilian electricity is a
nightmare.
Aviation style c/b's...? Some were but most of ours were for 120/230VAC.
Do Not Archive
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"The man who carries a cat by the tail learns something that can be learned
in no other way."
- Mark Twain
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