| 摘要 |
PROBLEM TO BE SOLVED: To provide a charge protection circuit wherein a time required for operation check is shortened and it is unnecessary to provide an external terminal for this purpose. SOLUTION: The charge protection circuit includes: multiple first comparing means 12A to 12C, 13A to 13D that compare the respective both-end voltages of multiple secondary batteries BTA, BTB, BTC, BTD connected in series with a direct-current power supply and charged thereby with a first predetermined value to determine whether overcharge has occurred; multiple second comparing means 14A to 14D that compare the respective voltages of external terminals with which the multiple secondary batteries are connected with a second predetermined value to determine whether or not a time shortening instruction has been given; an oscillating means 17 that oscillates when any of the first comparing means determines that overcharge has occurred; oscillation frequency changing means SW1, M4 that enhance the oscillation frequency of the oscillating means when any of the second comparing means determines that a time shortening instruction has been given; and a timer means 18 that counts time using an oscillation signal outputted by the oscillating means and outputs a charge stop signal when a predetermined time has passed. Thus, the secondary batteries are prevented from being overcharged. COPYRIGHT: (C)2007,JPO&INPIT
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