| 摘要 |
<P>PROBLEM TO BE SOLVED: To continuously detect induced voltage at low cost, and drive a motor with high efficiency. <P>SOLUTION: A coil current detection unit 30 detects a current component flowing through a coil. A scaling unit 38 scales a drive signal. An induced voltage component extraction unit 42 extracts an induced voltage component by removing the drive signal, scaled by the scaling unit, from the coil current component detected by the coil current detection unit. A phase difference detection unit 74 detects a phase difference between the phase of the drive signal and that of the induced voltage component. A signal adjustment unit 14 adjusts the drive signal so that the phase difference detected by the phase difference detection unit 74 is brought close to a target phase difference. <P>COPYRIGHT: (C)2011,JPO&INPIT |
