Abstract: Based on the H-bridge control technology, a large power drive circuit for DC motor is designed. The circuit has a dead time control and overcurrent protection function. System logic by single-chip computer, photoelectric isolating circuit, logic control circuit, discrete component H bridge driving circuit, current sampling circuit, filter detection circuit, linear amplification of isolating circuit and so on seven parts. This paper mainly introduced through the logic circuit and temporal sequence of clever control, curb the phenomenon of H bridge driver direct and without and the control circuit of dead area, can be in the positive and negative to the reliable running of motor. The system is characterized by simple structure, strong reliability and better output power than IC drive.

Key words: H bridge, PWM, DC motor, Drive, Logic control