| 摘要 |
PURPOSE:To make it possible to detect the service life exhausion of a battery beforehand, by providing a judge part for judging the life o the battery, a resistance value change part and a comparison part. CONSTITUTION:The transistor Tr of a resistance value change part 3 is brought to a continuity state in part 3 is brought to a continuity state in response to an inspection signal S1 and the resistance change part 3 changes from a high resistance state to a low resistance state which a large current is flowed from a battery (a) through the resistance value change part 3. That is, the output voltag of the battery (a) is lowered. After a slight time is elapsed, a judge part 2 stops the output of the inspection signal S1 and the passing current of the resistance value change part 3 is reduced. Further, first voltage dividing resistors r1, r2 are imparted to the first comparision terminal C1 of the comparator C of a comparison part 4 and second voltage dividing resistors r3, r4 are imparted to the second comparison terminal C2. The comparator C compares terminal voltages at both first and second comparison terminals C1, C2 and outputs a comparison signal S2, for showing voltage difference. The judge part 2 responds to the magnitude of this comparison signal S2 to judge the service life of the battery (a).
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