---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 03/14/11: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:38 AM - Radio Reception Problem (Bill Bradburry) 2. 02:59 PM - Re: Re: latching relays (Jeff Luckey) ________________________________ Message 1 _____________________________________ Time: 07:38:44 AM PST US From: "Bill Bradburry" Subject: AeroElectric-List: 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 _____________________________________ Time: 02:59:39 PM PST US From: "Jeff Luckey" Subject: RE: AeroElectric-List: 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 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.