Soft-start circuitry for DC motor

摘要

This paper presents a soft-start circuit using the pulse-width-modulation (PWM) method. The motor is controlled by the dc chopper associated with a low-cost PWM chip TL494. The design criteria are stated. The motor HC385MG is tested in experiment. The results illustrate that the circuit effectively reduces the inrush current at start-up moment. The circuit also provides the speed adjustment and can be further implemented with the speed regulation and the over-current protection.