Flyback Transformer Drivers

Solid-State Flyback Driver

I built this solid state flyback driver based on a micro solid-state Tesla coil circuit created by Steve Ward. The schematic is reprinted here with credits to Steve Ward: microsstc.jpg.

Instead of an air-core Tesla Coil setup, I used a flyback. Also I used a IRFP450 MOSFET, which is rated about 4A less than the IRFP460 MOSFET. The transformer I used is ~30V 2A. I used a standard 8-pin socket instead of two 4-pin sockets for the two ICs (TC4420 and 555 timer). Otherwise, the design is largely the same as the SSTC implementation and relies on an antenna near the flyback for oscillation feedback.

Solid-State Flyback Driver

1-inch discharges

Big lightbulb used as a plasma globe

I recorded a video of the solid-state flyback driver in 2024, about 20 years after it was built and it still works!

Vacuum Tube Flyback Driver

This tube flyback driver is based on vacuum tube tesla coil (VTTC) and high voltage generation circuits in tube TVs. Below is the schematic of the tube flyback driver.

The 6BG6 tube is a TV output tube that drives the flyback transformer. The 12SQ7 is a high-gain amplifier that boosts the signal from the flyback feedback coil to oscillate the 6BG6 tube. The power transformer was salvaged from a small HP frequency counter, and has 250V, 18V, and 7V windings. The 250V winding is fed in a voltage doubler which brings it up to around 600V, but drops to around 300 to 400 volts loaded. The 18V winding feeds the 6V 2.5A filament of the 6BG6 tube, which works alright and the voltage drops to about 5V loaded. The 7V winding is fed into another voltage doubler to bring up the voltage to around 10V to 15V for the 12V filament of the 12SQ7. The circuit is self-resonant due to the use of feedback to trigger the oscillations so there is no frequency alignment necessary.

I recorded a video of the tube flyback driver in 2024, about 20 years after it was built and it still works every time!