Today's Message Index:
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1. 05:52 AM - Getting wires into the engine plenum (through the baffles) (donjohnston)
2. 12:10 PM - Re: Over Voltage on Start Up (Robert L. Nuckolls, III)
3. 02:38 PM - Bad Crimp? (Dave Saylor)
4. 04:28 PM - Looking for a circuit that when you press a button powers the device but .... (Jeffrey Skiba)
5. 05:46 PM - Re: Looking for a circuit that when you press a button powers the device but .... (Henador Titzoff)
6. 06:59 PM - Re: Bad Crimp? (nuckollsr)
7. 07:06 PM - Re: Looking for a circuit that when you press a button powers th (nuckollsr)
Message 1
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Subject: | Getting wires into the engine plenum (through the baffles) |
What's the best way to get the various sensor wires (fuel press, fuel flow, etc.)
from the engine to the firewall?
Passing them through a small hole with a grommet seems the easiest. But that would
require cutting and re-terminating the wire if sheet metal ever has to come
off (not that that's a common task).
There's a ton of "pass-through" style connectors, but that adds three new contact
points in the line.
Just wondering what's... typical.
-Don
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=408553#408553
Message 2
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Subject: | Re: Over Voltage on Start Up |
I have 40 hours on my lancair es and have been trying to solve a
charging problem since the first startup in july. I have a vertical
power electrical system (vp-200), a b&c voltage regulator (lr3c) and
an io-550n with a stock 60 amp alternator. Five seconds after engine
start vertical power switches power on to the voltage regulator. The
alternator comes on and vertical power senses an overvoltage and
disconnects the power to the regulator. After resetting the vertical
power sometimes two or three times over a 30 second time period the
system holds and remains fine for the balance of the flight.
I replaced the voltage regulator with an identical replacement with
no change. Another clue is that when the system first starts holding
in the voltage is on the high side close to 31 volts.
There's something fundamentally wrong here. The voltage
should NEVER be higher than the regulator's set-point.
Readings of 31 volts suggests that the regulator is not
getting 'real' bus voltage sample which is critical to
proper operation.
Attach a (+) lead of a voltmeter to the regulator's bus
voltage sense terminal (#3) and the (-) lead to regulator
ground terminal (#7). Tell us what you read when the
VP screen is reporting 31 volts. It sounds like the
regulator 'believes' it's doing a good thing while in
fact, the data it's operating on is bogus.
How is the regulator grounded?
Where does terminal (#3) get it's power?
Over time maybe ten minutes it settles down to 28.6 for the
remaining flight. I also hear a faint alternator squeal in
my headset. I am using two odyssey pc535 12 volt batteries in
series and they are at the rear of the plane connected with #2 welding cable
This has the 'smell' of a grounding issue where battery
recharge currents are polluting the regulator's ground
reference causing it to operate at something other than the
set-point.
Try dismounting the regulator, disconnect existing wire
from terminal #7 and run a test wire from #7 to the
crankcase. I'm thinking that you may see the ov
condition disappear. Can you describe your ground system
for us?
Bob . . .
Message 3
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Bob,
Can you tell from the photo if this is this a poor crimp? It was
overheating on the back of a strobe switch. I recall Bill Watson had a
crimp fail on a strobe switch recently as well. The strobes were
occasionally intermittent but the wire near the terminal was always very
hot to the touch. The insulation was discolored too.
I changed the terminal and the last few inches of wire, and now all is
well. Nice and cool.
Any comments on the crimp would be much appreciated.
Dave Saylor
831-750-0284 CL
Message 4
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Subject: | Looking for a circuit that when you press a button |
powers the device but ....
Looking for a circuit that when you press a button powers the device but ....if
the button is held on it is only powered for a max setting (say 3 seconds) but
this same circuit should stop if the button is released before the 3 seconds.
Hope that makes sense, I bet it exists already and I just am searching under the
wrong name.
Thanks in advance for the help
Jeff.
Message 5
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Subject: | Re: Looking for a circuit that when you press a button |
powers the device but ....
Jeff,=0A=0AI believe you need a better spec.- For example, you say that w
hen the button is pressed, the device is powered on.- Then you say if the
button is released before the 3 second interval, it should stop powering t
he device.- Or at least that's what I think you said.=0A=0AI think you ne
ed to divide it into the following functions:=0A=0A* If the button is pr
essed for less than N seconds, function 1 happens=0A* If the button is p
ressed for more than N seconds, function 2 happens=0A* If the button is
held for exactly N seconds, well never mind, there is no such thing unless
you have an accuracy spec.- If you do, then function 3 happens.- These
three functions need not be mutually exclusive.=0A=0A-=0AWhatever functio
nality you want, I believe a microcontroller or CPLD will do the job.- If
you describe your functionality more accurately, including output voltage,
current, etc., then this group can recommend specific products, including
boards.=0A=0A=0AHenador Titzoff=0A=0A=0A________________________________=0A
From: Jeffrey Skiba <jskiba@icosa.net>=0ATo: "aeroelectric-list@matronics.
com" <aeroelectric-list@matronics.com> =0ASent: Friday, September 13, 2013
7:27 PM=0ASubject: AeroElectric-List: Looking for a circuit that when you p
ress a button powers the device but ....=0A =0A=0A--> AeroElectric-List me
ssage posted by: Jeffrey Skiba <jskiba@icosa.net>=0A=0ALooking for a circui
t that when you press a button powers the device but ....if the button is h
eld on it is only powered for a max setting (say 3 seconds) but this same c
ircuit should stop if the button is released before the 3 seconds.=0A=0AHop
e that makes sense, I bet it exists already and I just am searching under t
===============
Message 6
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I think the evidence is pretty conclusive. ANY terminal that gets hot is victim
to heat dissipated in some resistance between wire and terminal or terminal and
installation surface . . . or both.
Compare the appearance of cross section for the terminal you replaces versus a
terminal I sectioned for this article:
http://tinyurl.com/kfk6jss
The terminal you removed was definitely not INTIMATELY mated with the wire strands.
There are voids between strands and a large void in the cavity adjacent to
captured strands. In the "golden-crush", wires become indistinguishable from
the terminal's wire grip barrel.
Was the terminal the right size for the wire? If it was installed with a tool from
your shop, an investigation is warranted. You don't want to install a bunch
of terminals like that!
Bob . . .
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=408569#408569
Attachments:
http://forums.matronics.com//files/photo_135_164.jpg
Message 7
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Subject: | Re: Looking for a circuit that when you press a button |
powers th
Henador's suggestion is doable. There's probably a half dozen approaches to this
task. Questions:
How much current do you need to switch?
Can the switch be in the ground side of the load?
Do you mind if a relay is used . . . or is it a design goal
to be all solid state?
You may be able to do this for a few$ of discrete
components . . .
Bob . . .
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=408570#408570
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