| 摘要 |
An object of the present invention is to provide a power supply circuit capable of reliably detecting voltage abnormality with a simple circuit configuration. According to the present invention, a power supply circuit that supplies control supply voltage for giving a control signal to a switching element is provided with: a switching power supply (1) having a function of supplying the control supply voltage to the switching element by a required number of output circuits (1b, 1c) and a function of feedback control that keeps output voltage of an output circuit (1a) constant; and a monitoring circuit (3) that monitors the control supply voltage based on output voltage of the output circuit (1a) used for feedback control, and in the case of abnormality, outputs a signal for stopping output of the control signal, to a CPU (8) which is a control apparatus for the switching element (71, 72). |
