Inverter module board with PWM controller, FET driver, feedback and frequency control.
The generator is made on the SG3525 chip, which is a PWM controller. There is a tuning resistor on the board, which can be used to adjust the generation frequency.
Adjustment is made within 20-35 kHz. The field-effect transistor control driver is made on four bipolar transistors, from the output and from which field-effect transistors can be connected directly.
Board pin assignment:
Pin 1 - board power (12-24V)
Pin 2 - output 1
Pin 3 - board minus (ground)
Pin 4 - output 2
Pin 5 and 6 - output blocking input (optocoupler)
Pin 7 - blocking output
Pin 8 - microcircuit input for adjusting the output voltage (feedback)
The blocking input is made through an optocoupler, which is convenient if galvanic isolation is required between the microcircuit and the blocking sensor, the response current is about 5 mA. From the optocoupler, the signal is amplified by the LM358 operational amplifier to the level required for the SG3525 output blocking input.