-----Original Message----- From: Keith Schrader P.E. To: PICLIST@MITVMA.MIT.EDU Date: Saturday, May 01, 1999 9:24 AM Subject: Re: Generator - small >>> I believe Bike generators are actually magneto's, And the wont drive from >>> the wind >>> At least they were a jillion years ago >> >> >>They are usually AC output, if that's what you mean by magnetos. >>They spin a permanent magnet in a winding. >>There's no field control as in an alternator, so you get what you get. >> >>They need some sort of blade arraingement to function as a windmill, but >>I've seen this done, using a bicycle wheel, and plastic or metal between >the >>spokes to emulate the "american farm" type windmills. Not bad actually for >>this application, it's cheap and easy, if not technically efficient. > > >Now that I think about it you correct with the Magnet/ Field issue. I do >rember when you tried to turn them by hand they went kinda thump thump, not >smooth at all. > >Bike wheel, clever Idea > >Regards >Keith That's because a bike generator (at least the old ones i know only have a two pole magnet running between a two pole coil so it will try to allign in 180 degree steps Peter