| 摘要 |
<P>PROBLEM TO BE SOLVED: To continuously detect induced voltage at low cost and prevent a motor from stepping out. <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 38, from the coil current component detected by the coil current detection unit 30. 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 step-out prediction/determination unit 80 compares the differential value of the phase difference detected by the phase difference detection unit 74 with a detection threshold value for step-out prediction to predict step-out. <P>COPYRIGHT: (C)2011,JPO&INPIT |
