| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect short-circuit failures of capacitors of a filter circuit of a power supply part, related to a power supply abnormality detection circuit for the power supply part which feeds operation power to a load. <P>SOLUTION: The power supply abnormality detection circuit comprises a plurality of switching elements Q1 to Q4, and the filter circuit including a plurality of the capacitors C1 to C3, and detects the occurrence of an abnormality of the power supply part 1 which feeds a DC voltage or an AC voltage following the on/off-control of the switching elements Q1 to Q4 to the load 3 via the filter circuit. The power supply abnormality detection circuit also comprises: a detection means which includes an output voltage detection part 11 for detecting a ripple component of a switching frequency included in an output voltage of the power supply part 1, and AC detection parts 12, 13; a rectifying/smoothing means which includes rectifying/smoothing parts 14, 15 each rectifying and smoothing the ripple component detected by the detection means; and a comparison detection means which outputs detection signals of the occurrence of the short-circuit failures of the capacitors of the filter circuit of the power supply part 1 when an output signal of the rectifying/smoothing means is lowered to reference voltages Vr1, Vr2 or lower. <P>COPYRIGHT: (C)2009,JPO&INPIT |
