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1. 发明专利

JPH114551A BATTERY BACKUP UNIT 失效
公开(公告)号：JPH114551A
公开(公告)日：1999-01-06
申请号：JP15332097
申请日：1997-06-11
申请人： HITACHI LTD
发明人： OMORI TETSUO , MIYAUCHI MASASHI , FUKAMIZU YOSHIRO
IPC分类号： H02J7/34
摘要： PROBLEM TO BE SOLVED: To prolong the service life of a battery unit by connecting a resistor for shunting a current balancing an apply voltage between the terminals of each battery unit thereby decreasing the number of cells being undercharged or overcharged due to the variation of cell at the time of constant voltage charging. SOLUTION: A reference voltage Vr is set equal to the voltage Vs at a voltage dividing point when the charging voltage Vc is equal to the rated voltage of a battery. When the battery is charged after being discharged, output from a comparison amplifier 21 makes a transition from high to low upon transition of a DC power supply 2 from a substantially constant current operating region to a constant voltage region. Consequently, a relay coil 8 is brought into excited state from unexcited state and relay contacts 8-1, 8-2 and 8-3 are closed to connect resistors 4, 5, 6 and 7 between the terminals of respective battery units. According to the arrangement, the variation in the voltage across the battery can be suppressed and an undercharged unit can be eliminated regardless of the variation of the battery.

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