Today's Message Index:
----------------------
1. 05:42 AM - Re: Re: Pitot tube slightly plugged... (Harley)
2. 06:23 AM - Re: Pitot tube slightly plugged... (Eric M. Jones)
3. 06:34 AM - Re: Re: Pitot tube slightly plugged... (Harley)
4. 06:56 AM - Re: Re: Pitot tube slightly plugged... (Ken)
5. 07:54 AM - Looking to Buy a Stein Air Large Terminal Crimping Tool (stearman456)
6. 08:02 AM - Re: Misprint in Z-16, v.12/ OV with Rotax generators? (s)
7. 08:29 AM - Re: Yesterday's Project - Show & Tell (James Kilford)
8. 10:29 AM - Re: Misprint in Z-16, v.12/ OV with Rotax generators? (Ken)
9. 11:59 AM - Re: Misprint in Z-16, v.12/ OV with Rotax generators? (Robert L. Nuckolls, III)
10. 12:42 PM - Need Help Troubleshooting (Steve Thomas)
11. 12:52 PM - Re: Misprint in Z-16, v.12/ OV with Rotax generators? (Ken)
12. 03:10 PM - Re: Why did this AMP crimp on connection get singed and fail? (Bill Watson)
13. 03:11 PM - Re: Looking to Buy a Stein Air Large Terminal Crimping Tool (Peter Pengilly)
14. 03:42 PM - Re: Need Help Troubleshooting (Bill Watson)
15. 03:54 PM - Re: Looking to Buy a Stein Air Large Terminal Crimping Tool (stearman456)
16. 03:58 PM - Re: Looking to Buy a Stein Air Large Terminal Crimping Tool (Allen Fulmer)
17. 04:02 PM - Re: Looking to Buy a Stein Air Large Terminal Crimping Tool (MLWynn@aol.com)
18. 04:26 PM - Re: Misprint in Z-16, v.12/ OV with Rotax generators? (Sacha)
19. 05:43 PM - Re: Need Help Troubleshooting (Robert L. Nuckolls, III)
Message 1
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Subject: | Re: Pitot tube slightly plugged... |
I have Firefox, and am not sure how to do it with other browsers,
but it allows me to download and save the page directly as it is
in two steps.
First, when on the page, select "File" then "Save Page As...",
and select the location where you want to put it. It will
sutomatically save the text and html code as an htm file.
Second step, go back to the online page, select ANY image, RIGHT
click on it and select "Download All Images". Firefox will pick
the folder that you last saved to by default, which is probably
the one where you put the htm file, and download all the images
there as well.
To view it, simply click on the htm file on your computer and it
will load offline in your browser just as the original page did.
Harley
-----------------------------------------------------------------
On 9/23/2012 8:40 PM, RGent1224@aol.com wrote:
> Can you convert the document to PDF format so it can be easily
> saved
> Thanks,
> Dick
> In a message dated 9/23/2012 7:11:01 P.M. Central Daylight
> Time, deej@deej.net writes:
>
> <deej@deej.net>
>
> On 9/23/2012 2:07 PM, Robert L. Nuckolls, III wrote:
> >
> > An elegant solution Dj . . . how about some photos
> > of these critters in place. Let's do a little one-pager
> > for the AEC website archives.
> >
>
> Hi Bob,
> I did a quick little write-up on my website at:
>
> http://deej.net/aviation/bug-plug/
>
> Feel free to use the pictures and info on that page if
> you want to
> put something up on the AEC site.
>
> -Dj
>
> --
> Dj Merrill - N1JOV
> Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
> Glastar Flyer N866RH - = Use ilities ay -
> MATRONICS WEB FORUMS - List Contribution Web
> Site p;
>
>
> *
>
>
> *
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Date: 09/23/12
>
Message 2
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Subject: | Re: Pitot tube slightly plugged... |
Mud dauber wasps are the bane of small holes everywhere. I want to suggest that
an enterprising individual do the following long-term experiment (Actually, you
might try searching the USPTO first):
Let's see what attracts mud dauber wasps. Do many experiments with enough time
to allow the wasps to build nests (and taking the weather into account.):
1) Drill a grid of different size holes in a board. Mount the board in a location
know for having a known problem with the wasps. Do the WMDs (Wasps, Mud Dauber)
prefer a hole size? Log the result.
2) Repeat with a spectrum of different colors. Do the WMDs prefer a color? How
about in the UV? Log the result.
3) Repeat with various contrasting patterns around the holes (e.g. starburst, concentric
circles, snowflake, spirals, flower petals, angry jagged shapes...whatever
you can think of). Log the result.
4) Put a colored LED behind a series of the same size holes. Log the result.
5) Put a blinking LED behind a series of the same size holes. Try various colors.
Log the result.
6) Keep going until you find a solution.
7) Patent it. "Method of Preventing Aircraft Pitot Tube Obstruction by Mud Dauber
Wasp."
8) Pick up your Nobel prize in Stockholm.
9) Your MacArthur Genius Prize will be waiting when you return home.
Okay, perhaps that is going too far. But the airlines and pitot tube makers would
be very happy to pay for any workable results. Remember, every jet engine you
see has that curly snake on the nose cone. This reliably prevents birds from
nesting in the inlet. A bird will never come near anything that (in its tiny
bird brain) might possibly be a snake. I put a rubber snake on my rear deck which
absolutely keeps bird and their mess away.
The goal is to find something in the WMDs brain that works similarly. There are
myriad odd insect habits. Perhaps they won't ever come near a yellow pitot probe,
or one with UV-bright flower petals or a blinking LED...nobody knows. Several
solutions might be possible.
This would be a great science project, even for a whole classroom.
Good luck, and tell us what happens.
Addendum: See my website for a pitot tube of interest:
http://www.periheliondesign.com/downloads/thermopitot.pdf
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=383883#383883
Message 3
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Subject: | Re: Pitot tube slightly plugged... |
Very interesting idea, Eric! As a start to whoever wants to
attempt this, I had several two foot long pieces of 3/16 inch
shrink tubing hanging from a shelf in my garage. The daubers
plugged up the black tubing, but NOT the yellow, white or red!
Not very definitive, but all the openings were hanging in the
same location, bunched together. The black looked like it had
several years of nests in it, going a couple of inches up the
tubing on both ends, but the others were absolutely clear.
Harley
-----------------------------------------------------------------
On 9/24/2012 9:23 AM, Eric M. Jones wrote:
>
> Mud dauber wasps are the bane of small holes everywhere. I want to suggest that
an enterprising individual do the following long-term experiment (Actually,
you might try searching the USPTO first):
>
> Let's see what attracts mud dauber wasps. Do many experiments with enough time
to allow the wasps to build nests (and taking the weather into account.):
>
> 1) Drill a grid of different size holes in a board. Mount the board in a location
know for having a known problem with the wasps. Do the WMDs (Wasps, Mud Dauber)
prefer a hole size? Log the result.
> 2) Repeat with a spectrum of different colors. Do the WMDs prefer a color? How
about in the UV? Log the result.
> 3) Repeat with various contrasting patterns around the holes (e.g. starburst,
concentric circles, snowflake, spirals, flower petals, angry jagged shapes...whatever
you can think of). Log the result.
> 4) Put a colored LED behind a series of the same size holes. Log the result.
> 5) Put a blinking LED behind a series of the same size holes. Try various colors.
Log the result.
> 6) Keep going until you find a solution.
> 7) Patent it. "Method of Preventing Aircraft Pitot Tube Obstruction by Mud Dauber
Wasp."
> 8) Pick up your Nobel prize in Stockholm.
> 9) Your MacArthur Genius Prize will be waiting when you return home.
>
> Okay, perhaps that is going too far. But the airlines and pitot tube makers would
be very happy to pay for any workable results. Remember, every jet engine
you see has that curly snake on the nose cone. This reliably prevents birds from
nesting in the inlet. A bird will never come near anything that (in its tiny
bird brain) might possibly be a snake. I put a rubber snake on my rear deck
which absolutely keeps bird and their mess away.
>
> The goal is to find something in the WMDs brain that works similarly. There are
myriad odd insect habits. Perhaps they won't ever come near a yellow pitot
probe, or one with UV-bright flower petals or a blinking LED...nobody knows. Several
solutions might be possible.
>
> This would be a great science project, even for a whole classroom.
>
> Good luck, and tell us what happens.
>
> Addendum: See my website for a pitot tube of interest:
> http://www.periheliondesign.com/downloads/thermopitot.pdf
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=383883#383883
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
>
Message 4
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Subject: | Re: Pitot tube slightly plugged... |
Similar here. They like the black but not the clear transparent tubing.
Ken
On 24/09/2012 9:33 AM, Harley wrote:
> Very interesting idea, Eric! As a start to whoever wants to attempt
> this, I had several two foot long pieces of 3/16 inch shrink tubing
> hanging from a shelf in my garage. The daubers plugged up the black
> tubing, but NOT the yellow, white or red! Not very definitive, but all
> the openings were hanging in the same location, bunched together. The
> black looked like it had several years of nests in it, going a couple of
> inches up the tubing on both ends, but the others were absolutely clear.
>
> Harley
> ------------------------------------------------------------------------
> On 9/24/2012 9:23 AM, Eric M. Jones wrote:
>> --> AeroElectric-List message posted by: "Eric M. Jones"<emjones@charter.net>
>>
>> Mud dauber wasps are the bane of small holes everywhere. I want to suggest that
an enterprising individual do the following long-term experiment (Actually,
you might try searching the USPTO first):
>>
>> Let's see what attracts mud dauber wasps. Do many experiments with enough time
to allow the wasps to build nests (and taking the weather into account.):
>>
>> 1) Drill a grid of different size holes in a board. Mount the board in a location
know for having a known problem with the wasps. Do the WMDs (Wasps, Mud
Dauber) prefer a hole size? Log the result.
>> 2) Repeat with a spectrum of different colors. Do the WMDs prefer a color? How
about in the UV? Log the result.
>> 3) Repeat with various contrasting patterns around the holes (e.g. starburst,
concentric circles, snowflake, spirals, flower petals, angry jagged shapes...whatever
you can think of). Log the result.
>> 4) Put a colored LED behind a series of the same size holes. Log the result.
>> 5) Put a blinking LED behind a series of the same size holes. Try various colors.
Log the result.
>> 6) Keep going until you find a solution.
>> 7) Patent it. "Method of Preventing Aircraft Pitot Tube Obstruction by Mud Dauber
Wasp."
>> 8) Pick up your Nobel prize in Stockholm.
>> 9) Your MacArthur Genius Prize will be waiting when you return home.
>>
>> Okay, perhaps that is going too far. But the airlines and pitot tube makers
would be very happy to pay for any workable results. Remember, every jet engine
you see has that curly snake on the nose cone. This reliably prevents birds
from nesting in the inlet. A bird will never come near anything that (in its tiny
bird brain) might possibly be a snake. I put a rubber snake on my rear deck
which absolutely keeps bird and their mess away.
>>
>> The goal is to find something in the WMDs brain that works similarly. There
are myriad odd insect habits. Perhaps they won't ever come near a yellow pitot
probe, or one with UV-bright flower petals or a blinking LED...nobody knows.
Several solutions might be possible.
>>
>> This would be a great science project, even for a whole classroom.
>>
>> Good luck, and tell us what happens.
>>
>> Addendum: See my website for a pitot tube of interest:
>> http://www.periheliondesign.com/downloads/thermopitot.pdf
>>
>> --------
>> Eric M. Jones
>> www.PerihelionDesign.com
>> 113 Brentwood Drive
>> Southbridge, MA 01550
>> (508) 764-2072
>> emjones(at)charter.net
>>
>
Message 5
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Subject: | Looking to Buy a Stein Air Large Terminal Crimping |
Tool
Stein Air used to sell a crimping/swaging tool for #2, 4, and 6 AWG terminals,
product ID was TERMTOOL. I guess they're no longer able to get them. If someone
is done with theirs and would like to sell it I can promise it a good home.
Dan Jones warbirds@shaw.ca
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=383893#383893
Message 6
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Subject: | Misprint in Z-16, v.12/ OV with Rotax generators? |
Bob/Ken/Bob,
Thanks a lot for your replies.
BobMc> what about the case of the one in a million "abnormal" failure
where an OV occurs?
You're right... I have to keep reminding myself it's not how unlikely the
event is that counts, it's how bad the consequences could be (vs how easy it
is to design a redundant system to avoid those bad consequences... In this
case it's easy so should be done).
Ken> The regulator failed even though the overvoltage disconnect relay was
between the
Ken> alternator and the regulator so the voltage must have risen faster than
the relay
Ken> could open when the engine started. I credit Bob's crowbar ovm for
keeping the buss
Ken> voltage clamped though and preventing any further damage.
I'm not clear to me how the OVM could have achieved that. I thought the way
the OVM module works is that it grounds the number 4 pole in the S1 switch
in Z16/Z17 and therefore causes the breaker to open and disconnects the OV
relay.
BobN> I've not taken the time to really thrash through
BobN> the physics of a PM regulator. Seems it SHOULD
BobN> be designed to handle worst case failures including
BobN> unloaded operations. It can probably be done but
BobN> Z-17 is a work-around until the golden PM rectifier
BobN> regulator comes along.
I think you mean Z-16 is golden... Z-17 is the simplified version.
I would also be interested in how the RR as well as the permanent magnet
generator in the Rotax works. I'll dig around... Thanks again!
Sacha
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: domenica 23 settembre 2012 22:37
Subject: Re: AeroElectric-List: Misprint in Z-16, v.12/ OV with Rotax
generators?
--> <nuckolls.bob@aeroelectric.com>
At 11:18 PM 9/22/2012, you wrote:
Thanks Bob,
I almost didn't mention it as I thought it was "obviously wrongh but now
I'm glad I did as I learnt something! (Is there a detailed discussion of
how each Z figure works somewhere that beginners can read?). Still wondering
about the diff between the Z16 and Z17 alternator disconnect wiring.
Just variations on a theme. Primary design
goal is to achieve absolute control over energy
from the alternator as seen by the rest of the
airplane. Opening the DC pathway out of the
rectifier-regulator does that. Opening the AC
power into the regulator does too.
AC is generally easier to control than DC for
considerations of contact arcing. But given
the low duty cycle of stressful events in these
systems, either will do fine and last a long
time.
As Ken noted, the RR can be placed at risk for
high rpm ops without having the battery connected.
So while the control schemes presented in Z-16/17
are golden for the rest of the airplane, Z-17
carries the protection further back toward the
alternator and would perhaps have saved Ken's
RR from untimely demise due to the unloaded
condition.
I've not taken the time to really thrash through
the physics of a PM regulator. Seems it SHOULD
be designed to handle worst case failures including
unloaded operations. It can probably be done but
Z-17 is a work-around until the golden PM rectifier
regulator comes along.
I think you mean Z-16 is golden... Z-17 is the simplified version.
Bob . . .
Message 7
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Subject: | Re: Yesterday's Project - Show & Tell |
Very nice. Easy to fashion a cover for as well, if you're so inclined.
Also really handy for an aeroplane with a wooden firewall, as it reduces
the number of firewall bolts.
Makes me wonder why I didn't think of doing the same thing!
James
On 23 September 2012 22:45, Jeff Luckey <JLuckey@pacbell.net> wrote:
> ** **
>
> How about a little show-and-tell I=99m not sure that the
embedded picture
> will come thru, (if it does not, I will re-post)****
>
> ** **
>
> Picture of a panel of containing a master solenoid, start solenoid, shunt
,
> shunt fuses & ANL current limiter for the engine battery in my RV-7.****
>
> ** **
>
> Design Goals:****
>
> ** **
>
> 1. as compact as practical ( the mounting plate dimensions are 6
=9D wide
> x 5.5=9D tall)****
> 2. easy to install =93 (mounts to airframe w/ 4 screws)****
> 3. easy to work on (all of the interconnections were made while
> sitting at my workbench as opposed to working in-position on the airfr
ame)
> ****
> 4. easy to maintain (all fastenings are tapped into the base-plate
> thus not requiring access to the back of the panel after installation
for
> maintenance) ****
>
> ** **
>
> ** **
>
> Mounting:****
>
> ** **
>
> To be mounted <~12=9D from the battery on the firewall****
>
> ** **
>
> ** **
>
> Exercise for the reader:****
>
> ** **
>
> See if you can identify input & all outputs****
>
> ** **
>
> ** **
>
> Any & all questions, comments, & constructive criticisms welcome
****
>
> ** **
>
> ** **
>
> ****
>
> ** **
>
> ** **
>
> Jeff Luckey****
>
> ** **
>
Message 8
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Subject: | Re: Misprint in Z-16, v.12/ OV with Rotax generators? |
Hi Sacha
I might be a bit optimistic with that comment. My thoughts are that when
my OVM activates it immediately shorts out the relay but it is still
connected to the buss and is clamping the buss voltage until the circuit
breaker pops. So you are correct that with a slow opening relay and a
fast acting CB there could be a few milliseconds delay during which time
the voltage will be rising again.
Probably shouldn't mention it since I can't claim they are significant
but I also have a few TVS diodes on the buss. Since they are fast acting
and cheap they seemed like a good idea (several years ago) with an
electrically dependent engine.
Ken
On 24/09/2012 11:01 AM, s wrote:
> --> AeroElectric-List message posted by: "s"<uuccio@gmail.com>
>
> Bob/Ken/Bob,
>
> Thanks a lot for your replies.
>
> BobMc> what about the case of the one in a million "abnormal" failure
> where an OV occurs?
>
> You're right... I have to keep reminding myself it's not how unlikely the
> event is that counts, it's how bad the consequences could be (vs how easy it
> is to design a redundant system to avoid those bad consequences... In this
> case it's easy so should be done).
>
> Ken> The regulator failed even though the overvoltage disconnect relay was
> between the
> Ken> alternator and the regulator so the voltage must have risen faster than
> the relay
> Ken> could open when the engine started. I credit Bob's crowbar ovm for
> keeping the buss
> Ken> voltage clamped though and preventing any further damage.
>
> I'm not clear to me how the OVM could have achieved that. I thought the way
> the OVM module works is that it grounds the number 4 pole in the S1 switch
> in Z16/Z17 and therefore causes the breaker to open and disconnects the OV
> relay.
>
> BobN> I've not taken the time to really thrash through
> BobN> the physics of a PM regulator. Seems it SHOULD
> BobN> be designed to handle worst case failures including
> BobN> unloaded operations. It can probably be done but
> BobN> Z-17 is a work-around until the golden PM rectifier
> BobN> regulator comes along.
>
> I think you mean Z-16 is golden... Z-17 is the simplified version.
>
> I would also be interested in how the RR as well as the permanent magnet
> generator in the Rotax works. I'll dig around... Thanks again!
>
> Sacha
>
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
> Nuckolls, III
> Sent: domenica 23 settembre 2012 22:37
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Misprint in Z-16, v.12/ OV with Rotax
> generators?
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> --> <nuckolls.bob@aeroelectric.com>
>
>
> At 11:18 PM 9/22/2012, you wrote:
> --> AeroElectric-List message posted by: U<uuccio@gmail.com>
>
> Thanks Bob,
> I almost didn't mention it as I thought it was "obviously wrongh but now
> I'm glad I did as I learnt something! (Is there a detailed discussion of
> how each Z figure works somewhere that beginners can read?). Still wondering
> about the diff between the Z16 and Z17 alternator disconnect wiring.
>
> Just variations on a theme. Primary design
> goal is to achieve absolute control over energy
> from the alternator as seen by the rest of the
> airplane. Opening the DC pathway out of the
> rectifier-regulator does that. Opening the AC
> power into the regulator does too.
>
> AC is generally easier to control than DC for
> considerations of contact arcing. But given
> the low duty cycle of stressful events in these
> systems, either will do fine and last a long
> time.
>
> As Ken noted, the RR can be placed at risk for
> high rpm ops without having the battery connected.
> So while the control schemes presented in Z-16/17
> are golden for the rest of the airplane, Z-17
> carries the protection further back toward the
> alternator and would perhaps have saved Ken's
> RR from untimely demise due to the unloaded
> condition.
>
> I've not taken the time to really thrash through
> the physics of a PM regulator. Seems it SHOULD
> be designed to handle worst case failures including
> unloaded operations. It can probably be done but
> Z-17 is a work-around until the golden PM rectifier
> regulator comes along.
>
> I think you mean Z-16 is golden... Z-17 is the simplified version.
>
> Bob . . .
>
>
Message 9
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|
Subject: | Re: Misprint in Z-16, v.12/ OV with Rotax generators? |
At 12:28 PM 9/24/2012, you wrote:
Hi Sacha
I might be a bit optimistic with that comment. My thoughts are that
when my OVM activates it immediately shorts out the relay but it is
still connected to the buss and is clamping the buss voltage until
the circuit breaker pops.
Actually, it's a healthy battery that "clamps
the bus". During OVM reaction time the alternator
goes into max v current limited output with the
ship's accessories taking part of the load
and the battery working to soak up the rest.
Once the OVM trips, the current draw on the bus
WILL go up to 50+ amps . . . so I suppose there's
some additional clamping going on. A 5A breaker
with typical OVM loads opens in 15 to 50 milliseconds
so it's all over in a blink of an eye.
So you are correct that with a slow opening relay and a fast acting
CB there could be a few milliseconds delay during which time the
voltage will be rising again.
Relay, cb and ovm timing 'races' don't figure into
system functionality at all. Your electro-whizzies
manufactured to DO-160 design goals will stand off
20 volts for 1 second. The battery will keep bus
volts down to 17 volts or so. This give the OVM and
associated components all the time in the world to
do their intended job.
Probably shouldn't mention it since I can't claim they are
significant but I also have a few TVS diodes on the buss. Since they
are fast acting and cheap they seemed like a good idea (several years
ago) with an electrically dependent engine.
They don't hurt a thing . . . don't do anything
useful either. The TVS is designed to mitigate
low energy, fast rise, high voltage transients
that do not exist on your ship's DC bus . . . and
again, devices built to DO-160 intent are designed
to stand off the classic 'transient spike test'.
Years ago I spent a fist full of the boss's money for
my man Cecil to build a test fixture required for
GENERATION of the DO-160 test spikes. Cool gadget.
When we got it finished and calibrated, I began to
explore vulnerability for my favorite bus power
conditioning circuits.
I was astounded to find that when the device under
test had a simple capacitor of 1uF or more across
the incoming line . . . Cecil's Evil Spike Thrower
couldn't put a spear past it.
From that time onward, the fixture was never again
pulled down from the shelf . . . 'cause all our products
already featured the necessary capacitor. Had I
endeavored to analyze the fact mathematically
(or simply brass-boarded the circuit) I could have
used Cecil's time more productively.
Short answer is that the much dreaded and poorly
understood 'spikes' are already being run to ground
by MULTIPLE input capacitors that already exist
in your system. I have chased the elusive 'spike'
in airplanes from C-150 to Beechjets and have
never been able to capture one in the wild. The
ones I generated on the bench turned out to be
wimps.
Bob . . .
Message 10
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Subject: | Need Help Troubleshooting |
I've got a situation that appeared rather suddenly and I'm not sure where to start.
I was doing some tough-n-goes the other day when one of my low voltage lights
started flashing on downwind.
I've got a dual electrical system based on Z-14 with two LR3C-14s installed. For
the last 60 hours, everything has been running perfect. I fire up the engine
and I get 2 readings of 14.2 volts at idle. Suddenly, one of the systems will
not deliver any alternator voltage at idle. If I bring the engine back to
idle at any point, whether it be on the ground or in the air, the voltage drops
to 12.2 and begins a slow fall from there. As I increase the RPMs, the voltage
again rises to 14.2. The second system holds 14.2 volts the entire time.
Is there a way to figure out whether my problem is with the LR3C-14 or with the
alternator itself? Or possibly with my field circuit breaker? Or with the alternator
switch? I haven't a clue where to even begin. Suggestions welcome.
Steve Thomas
________________________________________________________________________
Message 11
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Subject: | Re: Misprint in Z-16, v.12/ OV with Rotax generators? |
I assumed that Sacha was referring to my example that I think
effectively had no battery in the circuit Bob. My little AGM battery was
completely flat. Afterwards it seemed that I could run the voltage up
and the battery would not absorb any current until it sat on the charger
for quite some time.
thanks for the review though. I for one really appreciate your real
world info and stories.
Ken
On 24/09/2012 2:57 PM, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 12:28 PM 9/24/2012, you wrote:
>
> Hi Sacha
>
> I might be a bit optimistic with that comment. My thoughts are that when
> my OVM activates it immediately shorts out the relay but it is still
> connected to the buss and is clamping the buss voltage until the circuit
> breaker pops.
>
> Actually, it's a healthy battery that "clamps
> the bus". During OVM reaction time the alternator
> goes into max v current limited output with the
> ship's accessories taking part of the load
> and the battery working to soak up the rest.
>
> Once the OVM trips, the current draw on the bus
> WILL go up to 50+ amps . . . so I suppose there's
> some additional clamping going on. A 5A breaker
> with typical OVM loads opens in 15 to 50 milliseconds
> so it's all over in a blink of an eye.
>
> So you are correct that with a slow opening relay and a fast acting CB
> there could be a few milliseconds delay during which time the voltage
> will be rising again.
>
> Relay, cb and ovm timing 'races' don't figure into
> system functionality at all. Your electro-whizzies
> manufactured to DO-160 design goals will stand off
> 20 volts for 1 second. The battery will keep bus
> volts down to 17 volts or so. This give the OVM and
> associated components all the time in the world to
> do their intended job.
>
> Probably shouldn't mention it since I can't claim they are significant
> but I also have a few TVS diodes on the buss. Since they are fast acting
> and cheap they seemed like a good idea (several years ago) with an
> electrically dependent engine.
>
> They don't hurt a thing . . . don't do anything
> useful either. The TVS is designed to mitigate
> low energy, fast rise, high voltage transients
> that do not exist on your ship's DC bus . . . and
> again, devices built to DO-160 intent are designed
> to stand off the classic 'transient spike test'.
>
> Years ago I spent a fist full of the boss's money for
> my man Cecil to build a test fixture required for
> GENERATION of the DO-160 test spikes. Cool gadget.
>
> When we got it finished and calibrated, I began to
> explore vulnerability for my favorite bus power
> conditioning circuits.
>
> I was astounded to find that when the device under
> test had a simple capacitor of 1uF or more across
> the incoming line . . . Cecil's Evil Spike Thrower
> couldn't put a spear past it.
>
> From that time onward, the fixture was never again
> pulled down from the shelf . . . 'cause all our products
> already featured the necessary capacitor. Had I
> endeavored to analyze the fact mathematically
> (or simply brass-boarded the circuit) I could have
> used Cecil's time more productively.
>
> Short answer is that the much dreaded and poorly
> understood 'spikes' are already being run to ground
> by MULTIPLE input capacitors that already exist
> in your system. I have chased the elusive 'spike'
> in airplanes from C-150 to Beechjets and have
> never been able to capture one in the wild. The
> ones I generated on the bench turned out to be
> wimps.
>
>
> Bob . . .
>
>
Message 12
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Subject: | Re: Why did this AMP crimp on connection get singed |
and fail?
Fascinating story with the switches. I could almost see Sherlock with
his magnifying glass examining the teeter-totter
If I understand correctly, you are saying that if there is
heating/singeing/burning going on in properly configured circuit, the
problem will be at the same location as the excess heating. Therefore, a
singed crimp suggests that the high resistance point is in the crimp.
Also, any voltage drop in a circuit will occur in the same place. In
my case, I had a splice-free line running from my fuse panel to the
strobe unit. Having detected the voltage drop, I imagined a chafed
wire but didn't expect that the hidden crimp barrel on one connector
would be the smoking culprit.
Increased resistance with a non-trivial current = voltage drop and heat
In my case, the voltage drop was enough to cause the strobe unit to
intermittently fire and there was enough heat to singe the crimp.
I knew that but now I "get it" a bit better in a real life situation.
Bill "it's elementary" Watson
On 9/23/2012 1:59 PM, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 04:08 PM 9/22/2012, you wrote:
>>
>> Bill,
>>
>> Search "switches with faston tabs" in the AeroElectric archives. They
>> discuss the discoloration of the faston insulation as the result of
>> switch failure. Time frame of sept 08.
>
> Yes . . . there was a 'rash' of failures manifesting
> in 'smoked joints' that started with loose rivets on
> the Carling switches. This prompted a lot of discussion
> and failure-analysis/tear-downs back about that
> time. Something to keep in mind as folks are unhappily
> blessed with such events.
>
> Look for a the loci of failure . . . sorta like a
> arson investigation. See which parts got hottest.
> These usually point to the area off poor connection
> where the degradation of the joints began. Several
> examples of over-heating in poor conduction areas
> are explored here:
>
> http://tinyurl.com/8d63v8x
>
> http://tinyurl.com/8zzkfbb
>
> http://tinyurl.com/8zzkfbb
>
> Whether bolting alternator brackets to crank-cases
> or keeping all the connections tight through
> a switch, the path to failure is the same. Increase
> in resistance increases heating and VOLTAGE DROP
> across a joint These two antagonists team up
> regeneratively to damage and perhaps fail the
> joint.
>
>
> Bob . . .
Message 13
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Subject: | Re: Looking to Buy a Stein Air Large Terminal Crimping |
Tool
Have you tried Bob Avery at Avery Tools? Try
http://www.averytools.com/prodinfo.asp?number=461
http://www.averytools.com/prodinfo.asp?number=TT5000
Peter
On 24/09/2012 15:52, stearman456 wrote:
>
> Stein Air used to sell a crimping/swaging tool for #2, 4, and 6 AWG terminals,
product ID was TERMTOOL. I guess they're no longer able to get them. If someone
is done with theirs and would like to sell it I can promise it a good home.
Dan Jones warbirds@shaw.ca
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=383893#383893
>
>
Message 14
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Subject: | Re: Need Help Troubleshooting |
Steve, this is just a shot in the dark. A fully charged battery with no
load should be producing over 12.6 volts. I'm wondering if you've lost
a battery.
Bill Watson
RV10 - Z-14
On 9/24/2012 3:41 PM, Steve Thomas wrote:
>
> I've got a situation that appeared rather suddenly and I'm not sure where to
start. I was doing some tough-n-goes the other day when one of my low voltage
lights started flashing on downwind.
>
> I've got a dual electrical system based on Z-14 with two LR3C-14s installed.
For the last 60 hours, everything has been running perfect. I fire up the engine
and I get 2 readings of 14.2 volts at idle. Suddenly, one of the systems
will not deliver any alternator voltage at idle. If I bring the engine back
to idle at any point, whether it be on the ground or in the air, the voltage drops
to 12.2 and begins a slow fall from there. As I increase the RPMs, the voltage
again rises to 14.2. The second system holds 14.2 volts the entire time.
>
> Is there a way to figure out whether my problem is with the LR3C-14 or with the
alternator itself? Or possibly with my field circuit breaker? Or with the
alternator switch? I haven't a clue where to even begin. Suggestions welcome.
>
>
> Steve Thomas
> ________________________________________________________________________
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
>
Message 15
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Subject: | Re: Looking to Buy a Stein Air Large Terminal Crimping |
Tool
Thanks Peter - I'll look into that.
Dan
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=383929#383929
Message 16
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Subject: | Looking to Buy a Stein Air Large Terminal Crimping |
Tool
I've got the Terminal Tool and it does a great job if you can put it in a
vice. Used as a portable tool it is pretty awkward. I made it work and the
results were fine but, as I say, it was a little awkward. Maybe if you had
a vice on a roll around bench that you could set beside the plane . . .
Allen Fulmer
RV7 still building
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Peter
Pengilly
Sent: Monday, September 24, 2012 5:12 PM
Subject: Re: AeroElectric-List: Looking to Buy a Stein Air Large Terminal
Crimping Tool
<peter@sportingaero.com>
Have you tried Bob Avery at Avery Tools? Try
http://www.averytools.com/prodinfo.asp?number=461
http://www.averytools.com/prodinfo.asp?number=TT5000
Peter
On 24/09/2012 15:52, stearman456 wrote:
>
> Stein Air used to sell a crimping/swaging tool for #2, 4, and 6 AWG
terminals, product ID was TERMTOOL. I guess they're no longer able to get
them. If someone is done with theirs and would like to sell it I can
promise it a good home. Dan Jones warbirds@shaw.ca
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=383893#383893
>
>
Message 17
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Subject: | Re: Looking to Buy a Stein Air Large Terminal Crimping |
Tool
I got a hydrolic crimper from harbor freight that works pretty well. I
have one from either Steinair or B&C. It is basically a whack-it with the
hammer till it looks right so of machine. I like the control from the HF
unit.
Regards,
Michael Wynn
RV 8 Finishing
San Ramon, CA
In a message dated 9/24/2012 3:12:36 P.M. Pacific Daylight Time,
peter@sportingaero.com writes:
--> AeroElectric-List message posted by: Peter Pengilly
<peter@sportingaero.com>
Have you tried Bob Avery at Avery Tools? Try
http://www.averytools.com/prodinfo.asp?number=461
http://www.averytools.com/prodinfo.asp?number=TT5000
Peter
On 24/09/2012 15:52, stearman456 wrote:
> --> AeroElectric-List message posted by: "stearman456" <warbirds@shaw.ca>
>
> Stein Air used to sell a crimping/swaging tool for #2, 4, and 6 AWG
terminals, product ID was TERMTOOL. I guess they're no longer able to get
them. If someone is done with theirs and would like to sell it I can promise
it a good home. Dan Jones warbirds@shaw.ca
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=383893#383893
>
>
Message 18
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Subject: | Re: Misprint in Z-16, v.12/ OV with Rotax generators? |
> I for one really appreciate your real world info and stories.
Me too, thanks again to both of you.
Sacha
Message 19
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Subject: | Re: Need Help Troubleshooting |
At 02:41 PM 9/24/2012, you wrote:
I've got a situation that appeared rather suddenly and I'm not sure
where to start. I was doing some tough-n-goes the other day when one
of my low voltage lights started flashing on downwind.
I've got a dual electrical system based on Z-14 with two LR3C-14s
installed. For the last 60 hours, everything has been running
perfect. I fire up the engine and I get 2 readings of 14.2 volts at
idle. Suddenly, one of the systems will not deliver any alternator
voltage at idle. If I bring the engine back to idle at any point,
whether it be on the ground or in the air, the voltage drops to 12.2
and begins a slow fall from there. As I increase the RPMs, the
voltage again rises to 14.2. The second system holds 14.2 volts the
entire time.
Do you not know which of the two systems is
powered by the SD-20 and which is powered by
the main alternator?
Is there a way to figure out whether my problem is with the LR3C-14
or with the alternator itself? Or possibly with my field circuit
breaker? Or with the alternator switch? I haven't a clue where to
even begin. Suggestions welcome.
I'm not sure anything is wrong. The SD-20 alternator
is DE-RATED to 20A due to limitations in RPM available
at the vacuum pump pad. The alternator begins life as
a 40A ND which is disassembled for salvage of useful
components and reassembled with new front end bell,
shaft mods, sheer coupling and removal of built in
regulator.
Borrowing from the B&C website we see this data
table:
Emacs!
Assuming 1:1.4 step up gearing for the vacuum
pump pad, a ramp taxi RPM of say 1000 yields
alternator RPM of 1400 where it can be
expected to deliver less than 15A. If bus
loads on the Aux alternator are significant,
bus voltage on that side can be expected to
drop below 13.0v warning value and the battery
will be expected to pick up some slack at voltages
similar to those you cited.
I would recommend that ground ops be conducted
with the cross-feed contactor closed except to
check Aux Alternator output during pre-flight
run up. After take off, add "Cross-feed Contactor-OPEN"
to your post departure checklist. You would also
reclose the cross-feed contactor during pre-landing
checklist.
The fact that you USED to get 14.2 at ground idle
before suggests that the cross-feed contactor
was closed. Now that you're seeing this disparity
of voltage between the two busses suggests that
the cross-feed contactor is open and the Aux
Alternator is performing pretty much as expected.
I wonder if -either- you've changed your modus
operandi for cross-feed management -or- the contactor
has become unavailable for some reason.
In any case, you should KNOW which of the two
alternators is used to power which suite of goodies
on the panel. This is an essential component of
plan-B development for operations with the Main
Alternator crapped.
Bob . . .
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