Today's Message Index:
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1. 01:10 AM - Re: Jabiru 3300 Over Voltage (user9253)
2. 01:30 PM - Re: Re: Jabiru 3300 Over Voltage (Robert L. Nuckolls, III)
3. 03:38 PM - Fw: Com antenna in LNC2 ? (Mike Wynn)
4. 03:50 PM - USB (Sam Staton)
5. 05:58 PM - Re: USB (James Kilford)
Message 1
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| Subject: | Re: Jabiru 3300 Over Voltage |
Good points Noel. In Rich's airplane, the alternator is actually a permanent magnet
dynamo. There are no field coils or brushes.
Rich, You mentioned in an earlier post that the circuit breaker was cool only
when the voltage sense wire is connected directly to the battery. That tells
me that the voltage regulator sense wire is carrying excessive current. That
is another indication that the regulator is bad.
Heat could be causing the regulators to fail. I suggest that a shroud be installed
over the regulator and that cooling air be forced into the shroud with
5/8" duct.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=368449#368449
Message 2
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| Subject: | Re: Jabiru 3300 Over Voltage |
At 09:37 PM 3/13/2012, you wrote:
> Have you seen any data source that argues with what's shown above?
No, I was going by Rich's schematic that shows the lamp connected to
the outside terminal of the voltage regulator. But now Rich has
explained that his drawing is a schematic and not a wiring
diagram. He is confident that the voltage regulator is wired
correctly. I believe him.
Okay.
I see 3 possible causes for the high voltage:
1. There is a wiring error.
2. There is an intermittent high resistance connection between the
main bus and the ignition terminal of the regulator, or between
regulator ground and aircraft ground.
I like this one. The whole purpose of a
dedicated sense lead is to prevent a sharing
of operating currents with measurement currents.
Obviously, the negative lead of the regulator
output is the case ground . . . which is also
the negative sense lead!
I'd go for an experiment to un-mount the regulator
from it's present location, attach a robust ground
lead from regulator case to ship's single point
ground. 10AWG would be good. Then go fly it and
see what the voltage does.
3. The voltage regulator is bad.
Maybe . . . but 'bad' regulators generally work
or don't work. This regulator is behaving like it
it is in distress but not failed.
_
Due to the fact that the 5amp circuit breaker gets warm, I suspect
the voltage regulator is bad.
It would be interesting to see what kind of
breaker he's using. The size of the heater in
a miniature breaker is so small
http://aeroelectric.com/Pictures/Breakers/Klixon_1.jpg
I cannot imagine how you get a enough continuous
load to 'warm' the breaker. Let's say you get
4.9999 amps flowing in the breaker to 'warm' it up
without tripping it. This implies that some soft
fault downstream of the breaker is dissipating
4.999 x 14 = 70 watts! That amount of energy being
dumped inside the regulator would probably get
you some form of gross failure or at least some
bad smells.
It seems to me that the voltage between the regulator ground
terminal and the regulator voltage-sense terminal should never go
above the set point (14.2). If it does, then the regulator is not
doing its job, regardless of any loose connections elsewhere.
Exactly . . . and the ground lead is highly
suspect.
The voltage is still too high, even with the voltage-sense wire
connected directly to the battery. That eliminates the circuit
breaker and the master switch as potential problems.
Bob, please correct me if my reasoning is faulty. Just do not tell
my wife that I made a mistake.
Sounds good so far.
Bob . . .
Message 3
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| Subject: | Fw: Com antenna in LNC2 ? |
> Hello Bob N. and group,
> Lancair 320 Com Antenna Question:
> I installed [3 years ago during v-stab build] one each com antenna and
> coax. This antenna is the black flexible printed-active-element style with
> the included (?) ground plane also printed parallel to the active-element.
> Antenna is installed/sandwiched-in-e glass cloth and resin in a almost
> vertical orientation inside glass v-stab. The plane is not flying yet. I
> have tested the antenna function and found to work properly for short
> distances, at home.
>
> Before I close the v-stab "forever," I would like to install a standard
> com whip antenna in the same v-stab, for T/R insurance in case the newer
> style [company no longer in business] fails to perform once flying. Will a
> disconnected SS (metal) whip antenna that is not connected to any coax,
> acccept a wire mesh ground plane, interfere (act as an unwanted
> grounded/reflector radiator) with the function of newer style flexible com
> antenna? Or should my "spare com antenna" be mounted elsewhere in the
> fuselage or wing tips?
>
> FWIW: THe Nav antenna is a copper-foil V, mounted against the top inside
> of the fusealge behind the roll-over (!) cage, with a TNC connector.
>
> Thanks very much as always, for any "been there, done that" replies.
>
> Mike W.
> Moab, UT
> ********************
Message 4
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I would like to set up a mini-USB bus in my panel. I have obtained 4 USB connectors
from L-com.com, and they appear to be ready to connect. My question to the
brain-trust here is this - do I need to setup a 5V regulator, or can I just
wire them up to ship's power (+12V)? Of course, the last thing I want to do is
destroy the expensive iPhone & iPad I want to connect to them! Any assistance
will be gratefully accepted. Thanks in advance!
Sam Staton
RV6 - getting close!
Message 5
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You will need to regulate to 5V. The specs for USB and in particular
charger ports are specific. If you want a quick, cheap & effective
workaround, why not buy a car USB charger and cannibalise?
http://www.amazon.com/HTC-T-Mobile-myTouch-Car-Charger/dp/B002TOKTHO/ref=sr_1_9?s=wireless&ie=UTF8&qid=1331772672&sr=1-9
is for sale at $0.01 + $2.95 shipping!
On 14 March 2012 22:47, Sam Staton <pj260@bellsouth.net> wrote:
>
> I would like to set up a mini-USB bus in my panel. I have obtained 4 USB
> connectors from L-com.com, and they appear to be ready to connect. My
> question to the brain-trust here is this - do I need to setup a 5V
> regulator, or can I just wire them up to ship's power (+12V)? Of course,
> the last thing I want to do is destroy the expensive iPhone & iPad I want
> to connect to them! Any assistance will be gratefully accepted. Thanks in
> advance!
>
> Sam Staton
> RV6 - getting close!
>
>
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