The goal: A power supply that outputs a solidly regulated +5.0VDC at 500+mA under load, fed from a ridiculously variable input supply - basically anything that can feed it enough juice to give the required output - Batteries, solar cells, a mini-windmill, a DC motor spun-to-operate-as-a-generator
- whatever.
As currently envisioned, I'm thinking of feeding it using a scavenged stepper motor that used to operate the tractor-feed of an old line printer - The unit I have in mind is labeled as wanting 40VDC at 10 amps, and after some creative wiring for testing, I've found that spinning it with fingers gets it to put out an extremely "wobbly" (and noisy as hell when looked at with an o-scope) 6-25 volts, with no idea what the amperage is - suspect it's probably pushing "a couple amps", give or take. (Yeah, I know... working to such close tolerances is a real pain in the arse :) )
I figure to mount it on a little push-cart I use frequently, friction-coupled to one of the wheels, MAYBE through a gear-train to bump up the RPMs. Ultimate goal: Charge/operate an iPod/iPhone/similar usually-USB-powered toy without ever needing to plug the unit into a "real" USB port.
Suggestions? Comments on feasibility? Diagnoses of my particular mental aberration(s) and/or ideas for suitable medications to cure it/them? :)