I have been thinking a lot about what to do for the Kinetic Project in Sustainable Energy. The idea is to find something in your life that you use or do which requires electricity, whether from an outlet or battery, and figure out a way to generate electricity to power whatever it is using your body. One of the most simple ways to generate a fair amount of energy is to turn a DC motor or Stepper Motor around and around. A motor is basically an electromagnet inside of a wire coil, and the motion of moving a magnet around a conductive material like coiled wire generates electricity. This is the reverse process of sending electricity to a motor, which gets it to turn.
For the Kinetic Project I am working with Gabriella Levine and Emily Webster to create hand-powered sound. We have a bunch of ideas for the output, like AM radio, a simple speaker powered by the AC signal coming out of a stepper, walkie talkies. Hopefully we’ll know soon what we want to make, but we’re fairly certain that we’ll use either a hand crank to turn our generator(s), or perhaps a pull cord starter (like the ones on a chain saw) in order to turn the generator more times with each gesture.
We might also incorporate the 555 timer circuits that Eric Rosenthal introduced in Basic Analog Circuits last Friday. Here is a list of a few of the many projects you can make with a 555 timer. The basic idea (as I understand it) is that the 555 IC creates an oscillating signal, which you can use for many purposes, like blinking two LEDs at different rates, giving power to an Arduino pin at specific intervals, or creating a sound wave. Eric Rosenthal pointed me to this project that uses a 555 timer to make an AM radio. Hackaday.com is also running a 555 timer contest right now so there are a lot of other neat projects that people are submitting.