Patent ID: 8977157
Filing Date: 2015-03-10
Classification: G03G,H02M

Abstract:
1. A switching power supply comprising: a transformer of which a primary side and a second side are insulated; a switching unit configured to connect to the primary side of the transformer; a control unit configured to control a switching operation of the switching unit; and a first detection unit configured to detect as a first voltage signal a current flowing through the primary side of the transformer and outputs the first voltage signal to the control unit, and a second detection unit configured to output a second voltage signal obtained by correcting the first voltage signal output from the first detection unit, to the control unit, wherein, in a case where the first voltage signal detected by the first detection unit is less than a threshold value, the voltage is output to the control unit from the first detection unit without passing through the second detection unit, and wherein, in a case where the first voltage signal detected by the first detection unit is equal to or more than a threshold value, the second voltage signal being corrected by the second detection unit is output to the control unit.