I will need galvanic isolation on my gate drives to prevent the main supply from shorting out, that is why I thought GDT. An optoisolator would work but only for lower frequencies. This is to replace my induction heater which operates at about 150 kHz, out of the range of my optoisolators. I could use transformers to couple my driver circuits to my oscillator and use floating supplies to power the drivers. I also thought I could use a transformer to replace the alternating push-pull outputs of my recently exploded SG3524 by winding two secondaries of oppisite polarity. But I heard that gate drive transformers do not always work well with PWM so maybe galvanically isolated drivers are the way to go. I already have two 12V regulated power supplies built on a circuit board so all I need to do is build the drivers. Also, on another topic is there a way I could replace my blown SG3524 with discrete components. I could do PWM with a comparator and capacitor, would a 555 be any good at higher frequencies?