i'm working on tesla coils engineering but trying to do as much solid state control I can for better tuning plus radiation safety http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1256402716
The solid state step-UP tesla coil works real good with mosfet switching control by arduino & ultra fast driver totally isolated from arduino.
The next stage is to make a solid state step-DOWN tesla coil but i don't want to do use a air spark gap aka plasma SCR for safety reasons (ultra wide band radiation) plus a bitch to tune :(
This is why I look for thyratron or valves "PWM interfaced" by arduino.
Please note this is equivalent to build a very high voltage boost-buck PSU brought to stochastic resonance.