Patent ID: 7843710

Claim:
A power converter for an image forming apparatus, comprising: an AC/DC rectifier which rectifies power source voltage and outputs DC voltage; an DC/AC inverter which is coupled to an output terminal of the AC/DC rectifier, inverts the DC voltage from the AC/DC rectifier to high voltage, and outputs the high voltage to a load of the image forming apparatus using a switch; and a controlling apparatus which controls operation of the switch of the DC/AC inverter; wherein the controlling apparatus comprises: a first circuit unit which is coupled to an output terminal of the power converter and generates a control signal based on voltage or current output by the power converter; a digital controller which outputs a gate signal for controlling intermittent operation of the switch of the inverter based on the control signal; a second circuit unit which is coupled to the output terminal of the power converter, detects at least one of overcurrent and overvoltage of the output terminal of the power converter and generates a detection signal based on detection of at least one of overcurrent and overvoltage; a third circuit unit which receives the detection signal from the second circuit unit, and automatically shuts off an output of the gate signal using hardware when the detection signal is generated; and a fourth circuit unit which revokes a state where the output of the gate signal is shut off according a revocation signal of the digital controller.