Patent ID: 7659726
Filing Date: 2010-02-09
Classification: H02J

Abstract:
1. An image forming apparatus comprising: a first AC power input cord to be connected to an AC source; a second AC power input cord to be connected to the AC source; a DC power supply unit connected to the first AC power input terminal; an AC load configured to receive AC power from the second AC power input terminal via an electric power control element; a voltage state detector configured to detect a voltage state of the second AC power input cord; a controller connected to the DC power supply unit, wherein the controller controls the electric power control element and determines whether the second AC power input cord is connected to the AC source based on the detecting result output by the voltage state detector; and an AC power supply controller configured to control an output from the AC source by opening or closing, wherein the AC power supply controller is connected between the second AC power input cord and the electric power control element; wherein the voltage state detector is connected between the second AC power input cord and the AC power supply controller, wherein the voltage state detector comprises a zero-cross signal detector configured to detect a zero-cross signal, wherein the zero-cross detector is connected between the second AC power input cord and the electric power control element, and wherein the controller is configured to determine whether the second AC power input cord is connected to the AC source, if the zero-cross signal detecting unit detects disappearance of the zero-cross signal.