I'll be chronicling my adventures in designing a usable and useful power system, powered by spinning wheels. I'm only just starting out so, though it should be "finished" in a week or fifty, I'll start by outlining my ideas.

1. Neodymium magnets can be found very cheap (by America-or-wealthier standards) and same for copper wire. 32ga magnet wire coiled into tiny giants, epoxied to a PVC circle and being passed within a small brush of the B field from some magnets I've JB-Welded to the spokes, should induce enough current to rectify-ify into a phone charge pretty easily. EMF is related to the number of turns of wire, and the time rate of change of magnetic flux, so I'm still trying to reconcile coil size with efficiency.

2. The system will be charged by the spinning front wheel. From a design standpoint, it makes sense to have a system that doesn't lose power to pedal (noun) resistance, nor requires pedal (verb) presense.

3. It will divert the alternating pedal-power into DC with a bridge rectifier, charging standard size batteries (AA, 9V, etc.) While not the most efficient, it'll power LED's and/or charge my phone, with the added bonus of letting me recharge batteries on the fly (find someone on the street who's blinker stopped blinking or whose music system stopped playing? Trade'em!)

4. It will build into the system as discreet as possible (in its physical construction) as not to encourage theft. It will also be as discrete as possible (in its effect) to encourage envy when it's running. We are, after all, trying to encourage others to do this.

5. It will accomodate charging an Ipod, cell phone and other USB interface devices. My phone has a built in MP3 player and room for a flash card, so it would be trivial to get a sound system running.

I've found one or two plans available for purchase, and plenty that are based inside the pedal casing -- I just can't figure out why anyone would buy them, and why anyone would build friction generators into a human-powered ride.

Update: Might be getting an OLPC laptop -- that'd be a good test of this generator's usefulness.