Abstract: A PWM power regulator device has a processor, an input interface circuit, a zero phase detecting circuit and a thyristor. The input interface circuit is connected to a PWM output terminal of an external digital control circuit and the processor. The processor calculates a period and duty cycle of a PWM signal from the PWM output terminal and then outputs a triggering signal to the thyristor. The thyristor is triggered at different conduct angle according to the triggering signal and the triggering signal is determined by the processor according to the PWM signal. Therefore, the power regulator device is directly connected to the PWM output terminal of the digital control circuit without digital to analog converter.