car relater but OT, generator Options

[wilchek]

I am trying to build a home generator off of a VW bug generator and a exercise bike. Ride the bike---see the light turn on, for a sciene project for kids. Does anyone know if the generator of VW bugs had "permanent magnets" or do I need to hook up a battery to the generator to develope a field current (energize the magnets). Any help would be great. Any other suggestions would help as well. I am at the trial and error part.

[wilchek]

Thanks Scott, that is what I thought


kind of, it will produce more than the battery puts out. It will produce some power without the battery hooked up. It is generally not strong enough without being an electromagnet. Your car alternator will not work without a battery. However, there are some generators/alternators that have what is called permanent magents that do not require external batteries but have less output (noramally power window motors have permanent magents). Bottom line, spin the gen/alt faster or add more magentics = more power.

Actually most voltage regulators work by adjusting power to the magnets, creating the proper amount of supply out of the alternator of around 13.5 volts.