----- Original Message ----- From: "Mike Hord" To: Sent: Sunday, November 30, 2003 10:11 AM Subject: Re: [EE:] Transferring power to a rotating circuit > >BUT it may be easier to simply use a fixed magnet and rotate a coil past it > >to generate voltage. > > In this case, where does the power come from? I know it'll work, but I'm > having trouble working out the source of the energy. Does it come from > the fan, indirectly? If we increase the load on the coil, does the current > draw of the fan increase? This may require some experimentation... > The power is generated by the coil windings passing through a magnetic field. This will cause a very slight load on the fan rotation due to the reactance of the magnetic field against the inductance of the coil winding. As you only want ma of current it should not effect the fan much as the fan will draw slightly more current from the supply to compensate for the extra load. Your problem will be to get enough windings for the voltage required (I can't remember the original voltage & current requirements for this thread). :-) Roy --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.545 / Virus Database: 339 - Release Date: 27/11/2003 -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics