Patent ID: 9496795
Filing Date: 2016-11-15
CPC Classification: H02M,Y02B

Claim Text:
1. A switching power supply apparatus comprising: a second switching element to which an input voltage is supplied; an output terminal connected to a load device; an input/output conversion circuit that converts the input voltage switched by the second switching element into an output voltage, and outputs the converted output voltage to the output terminal; a switching control circuit that controls switching operation of the second switching element, and has an off mode for stopping the switching operation in accordance with a signal input to an OFF terminal; a first rectifier circuit connected between the input/output conversion circuit and the output terminal; a transformer having a secondary winding wire whose first end is connected to a first terminal of the output terminal through a second rectifier circuit; a first switching element connected to a primary winding wire of the transformer; a pulse generator that supplies a pulse signal to a gate terminal of the first switching element; and a waveform detection circuit that detects a voltage or a current generated in the primary winding wire or the secondary winding wire of the transformer in accordance with operation of the pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result to the OFF terminal.