Rubber Band Joule Thief
This is a mechanical Joule Thief that will operate on very low voltage. A rubber band lightly stretched between two nails has two small neo magnets attached to it. An electromagnet, a reed switch and an LED are all that are needed to complete the oscillator. The motion of the magnets mounted on the rubber band cause a ‘make and break’ with the reed switch turning the electromagnet on and off. An LED connected across the coil catches the ‘flyback’ energy of the coil’s field collapse and lights up. The oscillator will operate down to .2 volt.