a switching circuit converting a DC input voltage into an AC voltage;

a transformer including a primary winding connected to the switching circuit, a first secondary winding and a second secondary winding;

a rectifier circuit including a first rectifier device, a second rectifier device, and a first junction point, and outputting a rectifier voltage from the first junction point and the first end portion, the first rectifier device being inserted between the first secondary winding and the second secondary winding, one end of the second rectifier device being connected to a first end portion which is an end portion of the second secondary winding on a side opposite to the first rectifier, the other end of the second rectifier device being connected to a second end portion which is an end portion of the first secondary winding on a side opposite to the first rectifier, the first junction point connecting the first secondary winding and the first rectifier device; and

a smoothing circuit including a first input end, a second input end, a first output end and a second output end, the first input end being connected to the first junction point, the second input end being connected to the first end portion, the first output end and the second output end being each provided corresponding to the first input end and the second input end, respectively, and the smoothing circuit smoothing a rectifier voltage being input into the first input end and the second input end so as to output the rectifier voltage to the first output end and the second output end.