| 摘要 |
PROBLEM TO BE SOLVED: To provide a charger which can detect a charge finish current with accuracy with a simple detecting circuit. SOLUTION: This charger includes a current detecting circuit which is connected to the negative load side of a secondary battery and detects a charge current and outputs an output current signal on one hand and switches the current detection into high sensitivity and outputs a detection mode which shows the switching of the detection sensitivity on the other, when the output current signal drops to a first set value or under, an output control circuit which controls the above charge means to perform constant current control to fix an output current signal until the output voltage reaches the first target value in the early stage of charge and to shift into constant voltage control to put the output voltage at the first target value when the output voltage reaches the first target value and to perform constant voltage control by raising the target value to the second target value higher than the first target value when the detected mode signal is switched into a high sensitivity detection mode, and a charge control circuit which finishes the charge when the output current signal drops to a second set value or under in the high sensitivity detection mode. COPYRIGHT: (C)2007,JPO&INPIT
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