"Flywheel Alternators" are more aptly described as Dynamo Charging systems.? They have fixed magnets that fly past a fixed Stator (coil or coils) to produce AC current and either a single or 3 phase A/C Output that is then rectified into DC.? A single phase unit either works or not as there are no moving parts to wear out.? If a wire breaks in the stator or beetween the stator and the regulator, it no longer works.? A 3 phase unit can lose a phase, which will reduce its max current output.? I expect the Great Planes units are likely single phase.? The regulator is where all the magic happens and where problems are most likely to occur.? The regulator both rectifies the AC output into DC, and regulates the DC to something less than 14.3 Volts.?Low voltage output will almost always be the regulator that's at fault. No charging can be either the regulator, wiring, or the dynamo stator wires that have failed. ? The failures I have seen in them were failed regulators, and burned wiring between the dynamo and the regulator, and broken wires in the dynamo.? It is possible that your regulator output may be affected by heat, but to what degree, I couldn't predict.? Since these systems don't typically charge at idle, you need to use a good voltmeter (preferably digital) and take a reading anywhere on the 12V DC buss with the engine turning somewhere around 1500 - 2000 RPM.? I don't have any specific knowledge about the Great Planes units, so don't know what RPM they cut in, but the ones on the Jabiru engines I've been working on seem to start charging around 1800 rpm.? Once it's charging with minimal load, I would expect to see something on the order of a minimum of 13V to maintain the battery.? If it is less than that, they you are likely looking at a regulator issue.? The dynamo itself will either work, or it won't. ? -Jeff Scott Los Alamos, NM ?
Sent:?Monday, June 13, 2016 at 2:02 PM From:?"Mike Stirewalt via KRnet" <krnet at list.krnet.org> To:?krnet at list.krnet.org Cc:?laser147 at juno.com Subject:?KR> Flywheel alternators Anybody know if the flywheel alternators that are in the Great Plains engines wear out with time? It seems my voltmeter needle is riding around 11 volts instead of 12 with the engine at full RPM. It might be my imagination. If they DO wear out with time, what needs to be replaced? What wears? I just aborted a trip to La Paz because the voltmeter needle seemed to be riding a little lower than it usually does. I didn't want to be coming back across the border without a working transponder so I landed in San Felipe and just came back home. Better safe than sorry. This alternator situation worries me but it might be just fine and my imagination the problem, not the alternator. It's got a lot of hours on it - the flywheel alternator I mean - and am wondering if I've got a problem developing. Thanks, Mike KSEE ____________________________________________________________ Affordable Wireless Plans Set up is easy. Get online in minutes. Starting at only $9.95 per month! www.netzero.net?refcd=nzmem0216[http://www.netzero.net?refcd=nzmem0216] _______________________________________________ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search[http://tugantek.com/archmailv2-kr/search]. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html[http://www.krnet.org/info.html] see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org[http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org] to change options
