Alternating current power supply device and integrated circuit for alternating current power supply device

摘要

An alternating current power supply device is provided with switch elements Q1, Q2 for converting direct current power from a direct current power supply Vin into alternating current power; a transformer T1 for converting the voltage of the alternating current power converted by the switch elements into other voltage; a load 20 connected to an output terminal of the transformer; a first detecting circuit 30 for detecting a first electric signal indicating power to be supplied to the load; a second detecting circuit 40 for detecting a second electric signal indicating the voltage of the direct current power supply; a feedback circuit 50 for generating a feedback signal based on the first electric signal detected by the first detecting circuit and the second electric signal detected by the second detecting circuit; and a control circuit 10 for generating a control signal based on the feedback signal from the feedback circuit and controlling on/off of the switch elements by the control signal so that power to be supplied to the load is at a prescribed value.