| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent explosion of an electrolytic capacitor or liquid leakage thereof by detecting the generation of short circuit failure of the capacitor or its state similar thereto. <P>SOLUTION: If the charging voltage of the electrolytic capacitor for supplying power to a load at the time of instantaneous voltage drop or instantaneous disconnection becomes V2, an auxiliary charging section execute charging and when the charged voltage increases up to Vf, the charging is stopped and the voltage is gradually decreased due to natural discharging. A timer starts time count simultaneously with the start of charging (S11), and if the time count exceeds a threshold Ta (Y in S13) before the charging voltage reaches Vf (N in S12), it is determined that the leakage current of the electrolytic capacitor is abnormally large, and the charging is prohibited and an alarm is outputted (S14, S15). In this way, an abnormal increase in leakage current of the electrolytic capacitor can be rapidly detected, and a user can grasp the status such as short circuit failure of the electrolytic capacitor. <P>COPYRIGHT: (C)2008,JPO&INPIT |
