This circuit drives small DC motors up to about 100 watts or 5 amps or 40 volts, whichever comes first. Using bigger parts could make it more powerful. Using a real H-bridge IC makes sense for this size of motor.Operation is simple. Motor power is required, 6 to 40 volts DC. There are two logic level compatible inputs, A and B, and two outputs, A and B. If input A is brought high, output A goes high and output B goes low. The motor goes in one direction. If input B is driven, the opposite happens and the motor runs in the opposite direction. If both inputs are low, the motor is not driven and can freely “coast”, and the circuit consumes no power. If both inputs are brought high, the motor is shorted and braking occurs. This is a special feature not common to most discrete H-bridge designs, drive both inputs in most H-bridges and they self-destruct. About 0.05 amp is consumed in this state.
This circuit drives small DC motors up to about 100 watts or 5 amps or 40 volts, whichever comes first. Using bigger parts could make it more powerful. Using a real H-bridge IC makes sense for this size of motor.Operation is simple. Motor power is required, 6 to 40 volts DC. There are two logic level compatible inputs, A and B, and two outputs, A and B. If input A is brought high, output A goes high and output B goes low. The motor goes in one direction. If input B is driven, the opposite happens and the motor runs in the opposite direction. If both inputs are low, the motor is not driven and can freely “coast”, and the circuit consumes no power. If both inputs are brought high, the motor is shorted and braking occurs. This is a special feature not common to most discrete H-bridge designs, drive both inputs in most H-bridges and they self-destruct. About 0.05 amp is consumed in this state.