When spun rapidly between the fingers, a bipolar stepper motor will generate around 10VAC. If this is stepped up with a small 240V to 6-0-6V transformer in reverse (with series connected secondaries), a small bipolar stepper motor is capable of powering a standard 5cm by 6cm luminescent sheet at full brightness. These are designed to be powered from 20V to 200VAC (typically 115VAC), producing 1.5 candelas of light - which will dimly light the average room, or adequately light a camp table. They are manufactured by Seikosha (RS Components Cat. 267-8726).
Circuit diagram:
Luminescent Generator Circuit Diagram
The transformer should be a small one (around 100mA or so), otherwise efficiency is compromised. The wires of the motor's two phases are usually paired white & yellow and red & blue. Just one of these phases is employed in the circuit. If a small bipolar stepper motor from a discarded 3.5-inch disk drive is used, the Luminescent Generator may be built into a very small enclosure. To sustain rapid, smooth spinning of the motor, a geared handle may be added.
Author: Thomas Scarborough - Copyright: Silicon Chip
