working ic sg3525 when there is power supply 12v To pin 13 and 15, at pin ct pin5, there will be a plus saw tooth output that is twice the frequency of the pwm out pin 11and 14.
Pin 16 must have 5v ref. Pin 2 needs more voltage than pin 1 so there will be plus output. We take pwm out to drive 2 sets of tr to drive the gate dri tranfprmer. In this circuit we use ee-19 thousand 25 turns 3 coil no- gap, the coils driving the mosfet must be in phase. In the circuit, the red dot will be circled as the phase of the correct leg position. Then take it to drive mosfet irf740 and drive transformers such as etd-49,etd44.