I built a circuit which I strapped one electrode to the bottom of my shoe, and the other to my leg. This circuit consists of a high voltage DC supply in my pocket driven by a 555 timer. When it works, I am able to make static sparks to objects with a capacitance to ground and huge sparks from my finger to grounded objects. The issue is that I have to keep replacing the 555 timer because high voltage must be getting back into it. What is the best way to protect the timer from high voltage and is that likely the cause? The whole circuit is powered by 9vdc.
Best Answer
I suggest using a combination of clamps and separation by other semiconductors being in the way.
simulate this circuit – Schematic created using CircuitLab
Something like that - to protect the 555 pin from inductive kickback, output voltage swings, separation by the totem pole driving circuit (which is a nice high-power fast switching bonus too) and clamp over the MOSFET to protect that, plus a clamp over the transformer.
Its as little overkill, but I think it's crazy enough to work! I hope others can critque/improve upon this suggestion.