CONTROL CIRCUIT AND POWER SOURCE DEVICE

Provided is a control circuit which can discharge a charge stored in an X capacitor with certainty even when an alternating current input voltage largely fluctuates. The control circuit for controlling a discharge of an X capacitor C connected between power source lines AC and AC having different polarities of an alternating current of an AC-DC convertor which receives inputting of the alternating current, converts the alternating current into a direct current, and outputs the direct current wherein the control circuit detects a change state of a voltage of the X capacitor C, and controls the discharge such that a charge stored in the X capacitor C is discharged based on the change state.