| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a characteristic deterioration detection circuit capable of detecting surely characteristic deterioration of an aluminum electrolytic capacitor. <P>SOLUTION: A three-phase brushless DC motor 109 is switching-driven by a MOSFET array 104 of a circuit board 102 arranged nearby. The aluminum electrolytic capacitor 103 is loaded in order to stabilize a feed voltage from a constant voltage source 101 positioned separately from the circuit board 102. A capacitor 105 DC-separates the negative electrode side of the aluminum electrolytic capacitor 103 from a comparator 108. A DC bias is applied to a negative phase input of the comparator 108 by BIAS 106, and a voltage acquired by adding a threshold 107 to the BIAS 106 as a reference voltage is applied to a positive phase input of the comparator 108. Hereby, even when the BIAS 106 is fluctuated, a voltage difference with the threshold 107 can be kept contact. Further, an output from the comparator 108 is served as a deterioration detection signal 110, and outputted when deterioration of the aluminum electrolytic capacitor 103 is detected. <P>COPYRIGHT: (C)2011,JPO&INPIT |
