In just one minute, you can shake your way to powering this battery-less light source known as a shaker flashlight.
The light from the flashlight comes from an LED, or a light emitting diode, through a lens.
The power for the LED stems from the movement of a magnet through a coil of wire on a tube. Each time the magnet moves through the coil of wires, the magnet generates a pulse of electricity. This is what happens when you shake the flashlight.
A capacitor allows you to use the flashlight without continuously shaking it. A capacitor works basically as a battery but with one big advantage: It charges immediately and, after just a few shakes, the flashlight is already usable.
An on/off switch completes the connection between the capacitor and the LED, turning it on by allowing the stored electricity to reach it.
Hand power doesn't just come from shaking a magnet back and forth. It's actually more common to find devices powered by hand-cranking. Pictured here is a boat's standing light that's powered in exactly this fashion.
Although we don’t tend to think of these when it comes to hand-powered devices, early automobiles once required hand-cranking in order to create the initial spark necessary for the engine to run.
This radio is both solar-powered and able to produce hand-cranked electricity to run. It's even equipped with a flashlight!
Get rid of unused papers, magazines or newspapers by using this hand-cranked shredder coffee table by Voos Furniture to create your own work of art.
Built by an Amish craftsman, this crank mixer by Lehmans works like a standard stand mixer except that it takes no power. With two speeds, this mixer is helpful when camping or during blackouts.
Kids give wind-up toys the power they need to run. These toys can operate in several ways, but the robot above works by turning its crank on the side! For more information, see 10 Essential Gadgets.