Recently I saw in old electronic magazine reprint of a project, where step motor was used as a source of power for LED torch. It's an interesting idea of using renewable and simple source of energy. Today I will present my own construction. It can be used as a source of energy for devices like a wall clock or a single LED.
The most important part is a 4 pin step motor from an old ink printer. By trial and error I found how to connect it's pins to obtain the biggest voltage. The motor produces AC voltage, so a diode bridge and capacitor were used to obtain DC voltage. Additional diodes and a resistor protect plugged circuit against to high voltage.
Below is presented that it can provide source of energy for a clock, LED and a small motor.
I think that it's an interesting idea of a simple, renewable and portable source of energy for small devices. It could be used in torches or (after improves) maybe even as a mobile phone chargers.