This circuit is intended for motion control applications, a common occurrence in robotics! This affordable PWM DC Motor controller can control any PMDC motor specified at 12 V to 30 V and 3 Amps max. Motor direction is controlled with a slide switch and motor speed, with an ordinary potentiometer.

The circuit diagram in Figure 1 shows ICs type LMD18200 and SG3525 at the heart of the circuit. The SG3525 is a pulsewidth modulator control circuit and the LMD18200, an H-Bridge to enable the motor to be run in both directions.