| 摘要 |
PROBLEM TO BE SOLVED: To detect an electric current with high accuracy by a magnetic flux detection type electric current sensor. SOLUTION: A battery ECU 200 calculates an offset value of a magnetic flux detection type ammeter 120. The battery ECU 200 comprises a circuit for permitting, based on a current value detected by the ammeter 120, the calculation of the offset value when the polarity of the detected current value is changed and the absolute value of the current value stays within a previously determined range continuously for a prescribed period of time, and a circuit for detecting that an ignition switch is turned off when the calculation of the offset value is permitted and calculating the current value detected by the ammeter 120 as the offset value. COPYRIGHT: (C)2004,JPO&NCIPI
|
