---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 05/16/09: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:47 AM - High pitch whine from KLN90 GPS (gmkonrad) 2. 03:10 PM - Re: EXP2BUS and non-functioning alternator (ianxbrown) 3. 03:26 PM - Re: Alternator excitation - suggested wiring? (mikef) ________________________________ Message 1 _____________________________________ Time: 07:47:37 AM PST US Subject: AeroElectric-List: High pitch whine from KLN90 GPS From: "gmkonrad" I recently installed a KLN90 GPS (I know its old, but it is better than my old loran) and it has a high pitch whine. I noticed the whine when I was wiring the gps on the bench, thinking I would not hear the noise in the plane-wrong. Would some kind of filter eliminate this or does it need to go to the shop ? I can hear the whine thru the headsets also and it gets annoying. Any ideas ? Thanks in advance, Gary Read this topic online here: http://forums.matronics.com/viewtopic.php?p=244264#244264 ________________________________ Message 2 _____________________________________ Time: 03:10:36 PM PST US Subject: AeroElectric-List: Re: EXP2BUS and non-functioning alternator From: "ianxbrown" I discovered that the IG lead to the alternator was only producing 12V when measured disconnected. As soon as a load was applied that went down to 1.5V. It turns out that some filings had got under the legs of an IRF4905 Mosfet and seemed to have shorted the pins. So, new question: Does anyone know how to test whether the cleaned up IRF4905 still works, and what the pinouts might be. There are three legs, but nothing I've read tells me what leg does what. Would I have to remove the IRF4905 from the board to test it's output? Thanks for your help so far, which got me to this point. Ian Read this topic online here: http://forums.matronics.com/viewtopic.php?p=244294#244294 ________________________________ Message 3 _____________________________________ Time: 03:26:05 PM PST US Subject: AeroElectric-List: Re: Alternator excitation - suggested wiring? From: "mikef" Bob, I wanted to update you. After getting a new alternator plug that has the connections I needed, I experimented and rewired the field and ground leads per your suggestions. WhaLa, alternator started outputting about 15 volts. Too high, but a few turns of the LR3C regulator screw has it now outputing 14.2 volts. And if I move the Master Switch to BATT position the alternator stops producing voltage. Like Hannibal Smith always said: 'I love it when a plan comes together'. I have a Z19 system, and here are the measured voltages from various instruments/locations: Digital meter directly on the main battery: 14.23 v Digital meter on the Z23 field wire to cockpit: 1.90 v Digital panel Voltmeter on Ebus: 14.10 v EM2 engine monitor connected to main bus: 14.44 v Is that Z23/field voltage what you might expect? Thanks again, Mike Read this topic online here: http://forums.matronics.com/viewtopic.php?p=244296#244296 ------------------------------------------------------------------------------------- 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.