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Mosfet Joule Thief

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A joule thief circuit with IRFP250N. This is the simplest form of joule thief circuit. There are no capacitors and diodes. Using a transistor in a joule thief circuit for generating high voltage is not convenient. Only a mosfet can handle the high currents needed in these circuits.

Input power is supplied from an adjustable buck boost converter. Buck boost converter gets power from a laptop adapter.

There is a 15 V zener diode connected between gate and source. Without zener diode mosfet dies in a few seconds.

There are approximately 750 turns at secondary side of the transformer. Input voltage to joule thief is around 15V. I did not bother measuring the output voltage. I think it is around 30kV.

Corona discharge to transformer core indicates that the insulation of the plastic frame of the transformer is not good enough. A little more voltage would break down and damage the plastic frame.

I can touch one side of the high voltage wires with a screw driver. This is not dangerous because current has no return path. But if I touch both sides with my both hands the current will flow through me. This will be dangerous.
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