I know, it looks like a space probe, but actually this is a solar battery charger. I found a set of 8 solar yard lights on sale for $10. I cut the solar cells out of them, wired up 2 series sets of 4 and and those 2 sets in parallel, and glued them to a piece of plywood. When I showed it off to a friend, he gave me 4 more yard lights that he didn't want anymore. That's why some of the cells don't match. In this picture It's actually being used to power a small radio inside the house directly, no batteries involved. And that's on a cloudy day.
Wind power! I'm a little more proud of this thing.
It puts out over 3 volts with no load most of the time. I have used it to charge 2 AA Ni-Cd batteries when they are wired in parallel. The most current I've seen this turbine deliver was 130 mA, but it's normally around 20-30 mA. It's enough to charge the two batteries over the course of a day considering that the wind fluctuates a lot.
With it not spinning you can get a better look at it. The blades are actually the rotor blades for an R/C helicopter, the body is PVC pipe, and the hub and fin are just plain old plywood. At it's heart is a 24 volt stepper motor. Steppers make excellent generators.
My next project is to build a scaled up version of this. I already have the motor and most of the materials, it's just a matter of ironing out some mechanical details. I'll post pics when it's done too.
