Generator
Edited by David Kang
Mechanics of Hand-powered Generators
The mechanics of hand-powered generators are not too complicated. They work like other generators, except the initial energy is provided by your arm rather than from steam by burning coal or a flowing river. A generator is basically an electric motor working in reverse. Both are based on principles of magnetism discovered by physicist Michael Faraday.
Faraday discovered in 1831 that passing a conductive wire through a magnetic field produced an electric current in the wire. By spinning a coil of wire around a magnet, he found that he could create a steady current. Thus, he could convert energy used to spin the coil into electrical energy. This principle powers generators that run on gasoline or diesel fuel, as well as the massive turbines in modern power plants, where the coils are turned by falling water or steam generated by burning coal or igniting nuclear reactions
How Hand Generators Work (from HowStuffWorks.com)
Hand-cranked generators can be use to demonstrate how energy can be converted from one form to another.
Making Your Own Hand-powered Generator
Since a generator is an electric motor working in reverse, it's fairly simple to make your own hand-powered generator. All you need is a cordless electric drill and a little knowledge about electrical wiring. Take the battery pack off the drill and wire the leads in the drill's battery compartment to whatever you want to power (rechargeable batteries work best). Affix a large handle to the drill's chuck, then hold in the trigger (as though you were activating the drill) and turn the handle. You may have to experiment with a voltmeter, changing the direction you turn the handle, and the torque and direction settings on the drill, but once you get it sorted out, you can charge the batteries by turning the drill by hand for a few minutes.