There has been a lot of interest in muscle powered electronic devices, due in large part to the success of Perpetual Torch
Perpetual Torch, also known as battery-less LED torch. The battery-less torch consists of a voltage generator to power the LEDs, an electronic circuit to condition and store the voltage produced by the voltage generator and high efficiency white LEDs.
The muscle powered voltage generator is based on Faraday's law, consisting of a tube with cylindrical magnets. The tube is wound with a coil of magnet wire. As the tube is shaken, the magnets traverse the length of the tube back and forth, thus changing the magnetic flux through the coil and the coil therefore produces an AC voltage. We will come back to this later in the Instructable.
This Instructable shows you how to build an electronic, batterless dice. A photograph of the built unit is seen below.
But first some background --->