Switch mode resonant transformer power supply.
Control output voltage with potentiometr.
LEDs show transistors control signals. Transistors ON time is tuned for half of the LC resonant circuit period. Full H-bridge loaded with LC circuit and transformer.
First 555 works in astable mode, generate pulses, frequency based on potentiometer.
Second 555 work in monostable mode generates 20us pulses.
FF devide frequency by two, for each transistor.
Input is 563VDC, typical for 3-phase rectifier output voltage for european 400VAC grid.
