| 摘要 |
A disk drive apparatus reproduces an information signal from a disk with a head, and outputs a processed information signal from the reproduced signal of the head. A movable member having a field part which generates field fluxes is coupled to the disk so as to rotate the disk directly. First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts. A switching operation block performs simultaneous on-off switching of the conduction control terminal sides of the first power amplifying parts, thereby causing first FET power transistors of the first power amplifying parts to perform high-frequency on-off switching. The switching operation block changes a peak of a pulsive conducted current signal from a DC voltage source to the three-phase windings responding with or corresponding to a rotation of the disk. As a result, three-phase drive currents to the windings vary smoothly, and the disk drive apparatus reduces a vibration and an acoustic noise of the disk. Further, the disk drive apparatus reduces a power consumption and a heat to the disk.
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