Direct current power supply circuit

This direct current power supply circuit includes: an alternating current power supply; a rectifying circuit that generates a direct current voltage from a supply from the alternating current power supply; a charging switch, which has an input terminal thereof connected to the rectifying circuit, and which outputs an output voltage corresponding to an input value inputted to a control terminal; a capacitor and a control circuit, which are connected to an output terminal; and a charging switch control circuit, which generates a switch-on signal when the output voltage is equal to or lower than a first reference voltage value, and which generates a switch-off signal when the output voltage is equal to or higher than a second reference voltage value, said second reference voltage value being higher than the first reference voltage value. A charging period setting circuit that includes the rectifying circuit and/or the charging switch control circuit sets a charging period, during which a charging current flows in the capacitor, and a non-charging period, during which the charging current does not flow in the capacitor. In the cases where the switch-on signal is generated during the charging period, the charging current flows in the charging switch when a direct current voltage is equal to or more than the output voltage, and in the cases where the switch-on signal is generated during the non-charging period, the charging current does not flow even if the direct current voltage is equal to or more than the output voltage.