15 February 2019
I was working on hardware needed for some of my proyects, and found this very simple self-oscillating driver circuit. It is capable to drive a half bridge with floating hi side drive up to 600v rail voltage and makes a very easy to build square wave oscillator. It makes a 50% duty cycle signal approximately, as it has a built in deadtime of 1.25uS; above 100khz this reduces the duty cycle significant , the limit is around 275khz where the deadtime cancels the signal completely. The drive capability is with 2 A peak not too high, but with low gate charge devices it works very well with about 150ns rise- fall time.
This circuit was originally published by DanyCZ as a simple Solid state teslacoil driver, I have changed some components, and planned to test it in a swimming pool ozoniser, where the spark gap device in long term operation is not very reliable. I think it could be useful in many applications where a resonant drive of a tank circuit is required, and the limited adjustment possibilities are acceptable.