| 摘要 |
PROBLEM TO BE SOLVED: To prevent erroneous overcurrent detection for accurate detection. SOLUTION: A controlling method includes a step for detecting whether a charging and discharging current flowing in a current-detecting resistor 14 is higher than or equel to an overcurrent detection current, actuating a timer 20 for counting a current-flowing time when the charging and discharging current is higher than or equal to the overcurrent detection current, and subsequently determining whether the counted time is longer than or equal to a predetermined delay time. When the counted time is longer or equal to than the delay time, a charging and discharging control FET is turned off to stop charging and discharging. In other words, it is determined that the overcurrent flows because a higher current still flows even when the counted time reaches the predetermined delay time. Alternatively, when the counted time is below the delay time, it is determined whether the charging and discharging current is higher than or equal to the overcurrent detection current. When the charging and discharging current is below the overcurrent detection current, the timer stops counting. In other words, the higher current is determined as a load rush current in this case because no higher current flows before reaching the predetermined delay time. COPYRIGHT: (C)2011,JPO&INPIT |
