---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 07/21/12: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:46 AM - Re: troubleshooting help needed (Robert L. Nuckolls, III) 2. 07:27 AM - Re: troubleshooting help needed (Robert L. Nuckolls, III) 3. 08:03 AM - Re: Aircraft Part Fell From Sky (Eric M. Jones) ________________________________ Message 1 _____________________________________ Time: 06:46:01 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: troubleshooting help needed At 03:10 PM 7/20/2012, you wrote: >Bill, >I am having a similar problem with my Lancair. The voltage seems to >float up and down about a half volt and I have had problems with the >transponder shutting down and the moving map resets. I hope my >problem is your problem and someone has a solution. > >Bill B > If a .5 volt excursion is causing your electro-whizzies to misbehave, there's something else going on. While it's viscerally satisfying to see a bus voltage reading stay locked down to within a tenth of a volt of the set point, having it vary by 1/2 volt under repeatable conditions should not be an operational issue. Your bus voltage should fly somewhere north of 14.0 volts . . . 14.2 was the 'sweet spot' when I worked at Cessna . . . 14.6 to as much as 15.0 volts seems to show up in contemporary automotive products. But 14.0 is the operating floor for making sure that a battery gets topped off a short time after takeoff. If your transponder is qualified for use in a type certficated airplane, it should operate without complaint down to end-of-battery-life voltage levels on the order of 11.0 volts. The moving map should be similarly qualified. For these devices to complain in concert suggests an intermittent condition that drops to levels much below your panel displays for bus voltage . . . a voltage level below battery supply voltage even. Loose connection? Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:27:10 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: troubleshooting help needed At 08:33 PM 7/20/2012, you wrote: [Luckey] Bob, is that correct - shouldn't Field & Bus voltage oppose each other? i.e. as Bus voltage goes up, Field current should go down? It depends on what is being held constant and what is being adjusted. If SYSTEM LOAD is the variable, then yes . . . the REGULATOR senses an INCREASE in bus voltage and reacts by REDUCING field voltage. In this instance, we're observing changes in system performance while the load is constant. If the field voltage rises in concert with the bus voltage, then the regulator is commanding that rise due to internal failure or mis-information in the voltage sense path and the alternator is performing normally. If the bus voltage falls while the field voltage rises, then the regulator is flogging a crippled alternator without success. Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:03:26 AM PST US Subject: AeroElectric-List: Re: Aircraft Part Fell From Sky From: "Eric M. Jones" Two questions: 1) What are the materials? If the right hand stuff is steel, I'd have to wonder if it was from a truck. 2) Depending on 1): How far from the I-60 Superstition Freeway is his house? -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=378855#378855 ------------------------------------------------------------------------------------- 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.