Patent ID: 8405938
Filing Date: 2013-03-26
Classification: H02H,H02M

Abstract:
1. A power supply module configured for converting an alternating current (AC) voltage to a direct current (DC) voltage and applying the DC voltage to a load, the power supply module comprising: a rectifying and filtering unit configured for rectifying the AC voltage into a primary DC voltage and filtering the primary DC voltage; a pulse width modulation (PWM) unit configured for generating pulses; a voltage transforming unit configured for transforming the filtered primary DC voltage into the DC voltage according to the pulses; a sampling and comparing unit configured for sampling the DC voltage, comparing the sampled DC voltage with a predetermined DC voltage pre-stored in the sampling and comparing unit, and generating comparison result as to whether the sampled DC voltage exceeds the predetermined DC voltage; and an overvoltage protection unit coupled between the sampling and comparing unit and the PWM unit; wherein the overvoltage protection unit comprises an overvoltage protection circuit and a PWM controller; when the sampled DC voltage exceeds the predetermined DC voltage, the sampling and comparing unit outputs an overvoltage signal to the overvoltage protection circuit, the overvoltage protection circuit generates a first driving signal, the PWM controller generates a first control signal and a locking signal in response to the first driving signal; the overvoltage circuit maintains to generate the first driving signal in response to the locking signal, and the PWM unit is disabled in response to the first control signal, and the overvoltage protection unit is self-locked.