This is a simple, low power, audio modulated flyback driver. The base oscillator uses a 555 timer with potentiometer to finely control frequency. The duty cycle is kept at 50% via signal diode between the threshold and discharge pins. Audio is injected to the 555 control pin via any standard operational amplifier. The output drives a single stage high gain, medium power class-a transistor amplifier that in turn drives the gate of a MOSFET or IGBT.
