Mini coil progress

I’ve made a little progress with the mini-coil. I have two flyback drivers up and running. Each circuit fits nicely inside a 2″ ABS cup potted with silicone, now dubbed the hockey puck of DOOM.


One flyback charges a capacitor bank, and is held open by the trigatron. I’m not sure when these actual trigatrons where manufactured, but they’ve been available since the 1940s.

The trigatron acts as a very quiet, easily controlled spark gap switch. When the second flyback turns on, it closes the switch, dumping the charge in the capacitor bank across the primary of the Tesla coil.


When actually operating, both coils will charge the bank in parallel, and the trigatron will be fired with very precise timing using a solid state ignition coil.


I’m working on a small Tesla coil project. After hours of winding and letting the polyurethane cure, there’s nothing quite like the thrill of finding the resonant frequency of your secondary + top load… 423 kHz for this little guy!

The frequency generator was a donation to the Unit. The scope is a DSO Nano v1. More updates to come…