A 12KV potential will jump 250mm!!! In my reality (Down-under) a 12KV
potential will arc over at around 10 - 25mm depending on frequency and
atmospheric conditions such as pressure and humidity, etc. To get 12 KV to
jump 250mm in 'normal dry air' would be quite some trick <g>.
David, one way of stepping down voltage is to place a DC potential across a
series of capacitors. 1000V across 10 series connected caps will provide a
charge potential across each cap of around 100V. Charge in series -
discharge in parallel, charge at 1000V - discharge at 100V (if using 10 caps).
Regards, Bill.