Patent ID: 9270163
Filing Date: 2016-02-23
CPC Classification: G03G,H02J,H02M,Y02B,Y04S

Claim Text:
1. A power source comprising: a rectifying unit configured to full-wave rectify an alternating current (AC) voltage to be input; a first converter configured to convert a rectified voltage from the rectifying unit to a first voltage; a zero cross detection unit configured to detect a zero cross of the AC voltage and supplied with the first voltage; a first capacitance element connected between an output side of the rectified voltage from the rectifying unit and a ground; a first discharging resistor connected to an input side of the AC voltage with respect to the rectifying unit and configured to discharge electric charges charged in the first capacitance element; a voltage detection unit connected to the first discharging resistor and configured to detect the AC voltage and output a signal corresponding to the detected AC voltage; a first switch unit configured to switch a signal supplied to the voltage detection unit and supplied with the first voltage; a second capacitance element connected to an input side of the AC voltage with respect to the rectifying unit and across two lines to which the AC voltage is supplied; and a second discharging resistor connected between an input side of the AC voltage with respect to the rectifying unit and the zero cross detection unit and configured to discharge electric charges charged in the second capacitance element, wherein the zero cross detection unit detects the zero cross of the AC voltage using a current flowing to the second discharging resistor and wherein the first discharging resistor is lower in resistance than the second discharging resistor; and wherein in a case where the power source is in an energy saving state, supply of the first voltage to the zero cross detection unit and the first switch unit is shut off.