Here’s a little howto on building a low-RPM generator from scratch. I assume that not all of you have extra hamsters lying around to power your night lights, but a similar design could be used for creating a small generator for wind or other energy sources.
Though it’s hard for the hamster to make higher voltages with his low-rpm wheel, he has torque to spare. 2 LEDs are barely taxing him……we are drawing only about 30 milliamps into the LEDs at Skippy’s top speed. If we add more electrical load to the circuit, he could make more power, with a resulting increase in physical resistance on the wheel—like running uphill. We have yet to try small incandescent flashlight bulbs in the circuit–something that draws more power and makes more physical resistance against the wheel spinning. We did try more LEDs — he had no trouble lighting up 6 of them. Next we plan to try an array of low-voltage incandescent flashlight bulbs to get optimum power output without tiring Skippy out too much. DanF is guessing that Skippy is good for 200 milliamps without tiring…
One cool thing is that the author uses a bicycle computer to track the hamster wheel’s average and top speeds over time. This is a nice tool to have if you’re trying to monitor and optimize the environment for your generator setup.
Hamster-Powered Night Light – Link