Patent ID: 6570357
Filing Date: 2003-05-27
Classification: G11B,H02P,Y10S

Abstract:
A disk drive apparatus comprising:a head for at least one of reproducing an information signal from a disk and recording an information signal on a disk; processing means for at least one of processing an output signal from said head and outputting a reproduced information signal, and processing an input signal and outputting a recording signal into said head; a movable member, having a field part, for driving said disk; Q phase windings, Q being an integer of three or more; voltage supplying means, including first and second output terminals, for supplying a DC voltage; Q first power amplifying means, each one of said Q first power amplifying means including a first power transistor for forming a current path between the first output terminal side of said voltage supplying means and one of said Q-phase windings; Q second power amplifying means, each one of said Q second power amplifying means including a second power transistor for forming a current path between the second output terminal side of said voltage supplying means and one of said Q-phase windings; altering signal producing means for producing altering signals; commanding means for producing a command signal in response to a rotational speed of said disk; first distribution control means for determining active periods of said Q first power amplifying means in response to output signals of said altering signal producing means, each of said active periods being larger than the period of an electrical angle of 360/Q degrees; second distribution control means for determining active periods of said Q second power amplifying means in response to output signals of said altering signal producing means, each of said active periods being larger than the period of an electrical angle of 360/Q degrees; and switching operation means for producing a modified command signal which responds with said command signal of said commanding means and has a part varied in response to at least an output signal of said altering signal producing means, producing a current detected signal in response to a current to said Q-phase windings from said voltage supplying means, and causing at least one power transistor among Q of said first power transistors and Q of said second power transistors to perform high-frequency switching in response to said modified command signal and said current detected signal.