摘要 |
A current detector (60) samples a motor current (MCRT_A) from a controlling sensor and a motor current (MCRT_B) from a monitoring sensor, and holds respective motor current maximum values (MCRT_Amax, MCRT_Bmax) at each prescribed operation cycle. An abnormality determiner (62a) detects that the motor current maximum value (MCRT_Amax) is in GND short-circuiting range and that the current difference between the maximum values exceeds a prescribed threshold value at each of successive operation cycles, to thereby determine an abnormality of the controlling sensor. Then, the abnormality determiner (62a) generates a detect signal (DET) specifying the current sensor abnormality and outputs it to a relay driver (64) and an alarm (66). Relay driver (64) receives the detect signal (DET) and generates a signal (SE) to turn off a system relay. The alarm (66) generates a signal (AL) and outputs it to display means arranged outside a power supply apparatus. |