Patent ID: 8599583

Claim:
A power supply circuit comprising: an input part, which has a first input terminal and a second input terminal, and which is configured to connect to an alternating current power supply; a line capacitor that is connected to the first input terminal and the second input terminal in parallel with the alternating current power supply; a rectification circuit, which is connected to the first input terminal and the second input terminal, which rectifies alternating current of the alternating current power supply and outputs to a load circuit from a high voltage side output terminal and a low voltage side output terminal; a smoothing capacitor, which is connected between the high voltage side output terminal and the low voltage side output terminal, which charges electrical charges output from the rectification circuit, and which discharges the electrical charges to the load circuit; and a remaining charge discharge unit that, when the alternating current flowing to the rectification circuit is interrupted in one of the first input terminal and the second input terminal, detects the interruption and discharges electrical charges remaining in the line capacitor to the low voltage side output terminal from the other one of the first input terminal and the second input terminal, which is different from the interrupted output terminal, based on charges of the high voltage side output terminal or electrical charges of the smoothing capacitor.