I was not sure if this should be posted as its own topic. However, my question deals with the topic discussed.

I want to power a miniature tesla coil using the short duration, high voltage transient created when the current powering an inductor is shut off. I'm hoping to get the a voltage high enough to jump a spark gap or perhaps a high voltage diode; to make the pulse unidirectional.

So my question is how can I generate the highest possible potential spike?

A very rapid shut off. Device suggestions?

Now the coil. Iron or air core? Higher or lower inductance? I would think a very long air inductor would be best. Is this correct? Is a single layer or multi-layer coil best? Is a flat coil better for higher voltages spikes?

I would love to hear any suggestions you can offer.

Thanks!