| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply which can discriminate the cause of a low voltage abnormality.SOLUTION: A switching element S1 is connected between a converter portion, which is formed of switching elements Q1, Q2, an inductor L1 and a capacitor C1, and an external connection terminal 13 to which a DC power supply V2 is connected. In a control state in which the switching element S1 is switched on and the switching elements Q1, Q2 are switched on and off, a voltage value Vs at a connection point between the inductor L1 and the switching element S1 is detected. When Vs≤Vth1, by the detection of a current value Is which flows through the inductor L1, when the current value Is is positive, an abnormality of the DC power supply V2 is determined, whereas when the current value Is is negative, an abnormality of the switching element Q2 is determined.SELECTED DRAWING: Figure 1 |
