| 摘要 |
PURPOSE:To reduce the time from the start of a damping action to the stationary state of an optical disk device by switching close timings of the high and low voltage sides for two of windings of a 3-phase DC brushless motor. CONSTITUTION:A star connection is used among windings 15a-15c of a 3-phase brushless motor which revolves a disk 1. Both a revolving position detector 4 and a pulse generator 5 produce timing signals respectively. While a speed detector 6 receives a signal from the generator 5 and detects the speed. In addition, switches 12a-14a of the high voltage side and switches 12b-14b of the low voltage side are provided to the driving ends of the windings 15a-15c respectively. The switch close timings are changed by switching circuits 9 and 10 between the high and low voltage sides of two driving ends of the windings. In such a constitution, a damping current can be supplied intermittently. In such a way, the time between the start of a damping action and a stationary state is reduced. |
