Control circuit and method for DC motors

Abstract

A control circuit and method for DC motors is disclosed in the present application. The control circuit may comprise a voltage monitoring unit for monitoring the output voltage of the DC power supply, a switching circuit for controlling the operation of the DC motor, and a PWM signal output unit to output PWM signal for controlling the switching circuit. The PWM signal output unit may be configured to regulate the duty cycle of the output PWM signal based on the results of the voltage monitoring unit. In this way, motors with different resistances may work continuously in a stabilized state. Also, it may detect when a load like motor is heavy loaded or overloaded, stop motor from starting, and avoid overtime working due to the drop of supply voltage damaging the load like motor. When the voltage of power supply is higher than the rated voltage of the motor, it may regulate the input voltage value of power supply to avoid the increase of excitation current of motor with the increase of the applied voltage, thereby avoid the loss of iron core.

Dependencies are inferred from the claim text.