| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and a circuit for offset compensation which correctly compensates offset of current detection, free from any effect of hysteresis characteristic, as well as a motor controller achieving accurate current control. <P>SOLUTION: In this offset compensation method, once a current control section 13 applies a first current to its circuit 5 of object and then stops. A current compensator 8 records the current value detected by a current detector 6 as a first detected value. Also once the current control section 13 applies a second current with the same absolute value and reverse sign as the first current to the circuit 5 of object and then stops. The current compensator 8 records the current value detected by the current detector 6 as a second detected value. Next, the current compensator 8 takes the average of these first and second detected values to calculate the offset, while the current control section 13 deducts this offset from the current value detected by the current detector 6 as a current flowing into the circuit 5 of object. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
