Patent ID: 7859873

Claim:
A DC/AC inverter, comprising: a voltage conversion circuit for stepping up or down input DC voltage while insulating; a DC/AC conversion circuit for converting output voltage of the voltage conversion circuit to AC voltage; a detection circuit for detecting that AC voltage is outputted from the DC/AC conversion circuit; and an operation control circuit for controlling the operation of the detection circuit, wherein ground level of the detection circuit has the same potential as the minus side of the input DC voltage, and the operation control circuit comprises: a rectifier circuit; a first capacitor connected between one input terminal of the rectifier circuit and one output terminal of the DC/AC conversion circuit, the first capacitor being for insulating the one input terminal of the rectifier circuit and the one output terminal of the DC/AC conversion circuit from each other; a second capacitor connected between an other input terminal of the rectifier circuit and an other output terminal of the DC/AC conversion circuit, the second capacitor being for insulating the other input terminal of the rectifier circuit and the other output terminal of the DC/AC conversion circuit from each other; and a comparator circuit for operating the detection circuit when output voltage from the rectifier circuit is higher than a threshold based on ground level of the detection circuit.