Joule thief is a simple step up converter, that converts DC to DC, for example you can drive a 3.4V Led with single 1.2V battery, even if the battery is almost dead. It extract all the energy stored in batteries.
- 1Kohm resistor.
- small NPN transistor ( for example 2N3904 ).
- ferrite toroid, (can be found on power supplies, radio), and wire to wrap around the toroid, ( big toroid and more turns = more output power and voltage you get ) the method of wiring is shown under, (if you don’t have the toroid try the other methods under).
- and Led or anything you can’t drive with one battery like: leds, lighting a neon lamp, charging capacitors with high voltage, charging other batteries Ex: charging 3.6V batteries with 1.2V battery…
you can change the 1.2V battery with 9V to get high voltage output that can drive neon lamps…
you can charge batteries…
A different types of coils can be used