Today's Message Index:
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1. 07:38 AM - Radio Reception Problem (Bill Bradburry)
2. 02:59 PM - Re: Re: latching relays (Jeff Luckey)
Message 1
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| Subject: | Radio Reception Problem |
I have a very noisy airplane particularly when in flight. I have the Garmin
GNS430W and I am using an old Sigtronics headset.
On the ground and taxiing, the radio works fine. When I am in the air, I
start getting a lot of noise in the headset and I can hardly understand ATC.
I think my sidetone goes away at this time as well. To be honest, it is so
bad that I am not sure. Nothing I have tried with squelch has seemed to
have any effect.
I don't know where to start to try and resolve this issue. Can anyone
suggest what I might do?
Thanks,
Bill B
Message 2
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| Subject: | Re: latching relays |
Circuits like these do have their places but I don't think controlling the
coil of a master solenoid is one of them.
This sort of smells like a solution looking for a problem. Keep in mind
that when you place more components in the critical path, the reliability of
the system goes down - no matter how reliable those components are.
In the case of master solenoids, (as Bob & others point out) they have
proven to be pretty darn reliable. Therefore so I would be reluctant to
"over-engineer" a solution to a problem that doesn't exist.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of user9253
Sent: Sunday, March 13, 2011 06:26
Subject: AeroElectric-List: Re: latching relays
Another option for using a conventional master contactor is to energize it
at full voltage, then hold it at reduced voltage. I believe that Bob was
working on a microprocessor based device that would do that. One could also
make their own reduced voltage holding circuit using a resistor or diodes to
drop the voltage along with a 3-position master switch: off, low voltage,
and normal voltage.
Or how about this IC along with a Power MOSFET?
http://ww1.microchip.com/downloads/en/DeviceDoc/21448c.pdf
I was going to use this IC to control the elevator trim servo. I think it
would also work with the master contactor. It applies full voltage for a
timed interval, then puts out a PWM voltage, for a price of $1.38.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=333732#333732
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