A first conversion section converts, into a first direct-current voltage, an alternating-current voltage input from input lines, and applies the same between power supply lines. A diode is arranged between the power supply lines such that an anode thereof faces toward the power supply line side. A capacitor has both ends connected to a direct-current load, and is connected in series with the diode. A switch section selects conduction/non-conduction between an alternating-current power supply and the first conversion section. A second conversion section converts, into a second direct-current voltage, the alternating-current voltage input without passing through the switch section, and is connected to a connection point located between the capacitor and the diode to apply the second direct-current voltage to the capacitor.