Patent ID: 7355826

Claim:
A power supply apparatus, comprising: a CPU having prescribed operation cycles including a shortest operation cycle; a power supply; a drive circuit for receiving supply of power from said power supply and driving a load circuit; and an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit; said abnormal current detection circuit including current detection means for detecting a maximum value of said drive current for each prescribed operation cycle, and abnormality determination means for determining whether the maximum value of said drive current exceeds a prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least 3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU.