Building a Small Tesla Coil

A solid-state Tesla coil (SSTC) using IGBTs and resonant gate driving is safer and more controllable than a spark gap coil. This is still high-voltage work — the secondary output can exceed 100kV and will arc several centimeters. Do not touch the secondary while operating.

The primary circuit: a half-bridge of IGBT modules (IRG4BC30W) driven by an IR2184 gate driver at the resonant frequency of the secondary coil. The resonant frequency of my 8-inch secondary was about 270kHz. A feedback pickup coil on the secondary feeds the oscillator input, creating self-resonant operation.

Output characteristics: 6-inch arcs to a grounded target, 3-inch streamers to open air. The coil draws about 200W from the mains at full power. Safety: the entire primary circuit is at mains potential. Use an isolation transformer and a ground fault circuit interrupter (GFCI). Never operate near flammable materials.