To provide a power supply circuit device that can relatively favorably feed power to a variable load such as an audio device or a device similar thereto, and is reducible in size and cost.

First and second capacitors C1, C2 are connected to AC power terminals 1, 2 via first and second rectifying circuits 3, 4. The first and the second capacitors C1, C2 are connected in series. One end of the first capacitor C1 is connected to a common terminal 7. The other end of the first capacitor C1 and one end of the second capacitor C2 are connected to a first power supply conductor 8. A back-flow preventive diode D1 is connected between the first power supply conductor 8 and a DC output terminal 6. A third capacitor C3 is connected between the DC output terminal 6 and the common terminal 7. A switch Q1 is connected between the other end of the second capacitor C2 and the DC output terminal 6. The switch Q1 is on/off-controlled on the basis of the output of a comparator 15 that determines whether or not the output is lower than a DC output voltage.