| 摘要 |
The invention is directed to a motor usable in a disk drive apparatus comprising: a rotor having a field part which generates field fluxes; Q-phase windings (Q is an integer of 3 or more); voltage supplying means, including two output terminals, for supplying a DC voltage; Q first power amplifying means,; Q second power amplifying means; position detecting means for producing a position signal which responds with a rotation of said rotor; and activation operation means for controlling active operation of said Q first power amplifying means and said Q second power amplifying means responding with said position signal of said position detecting means; said activation operation means comprising: time measuring means for measuring a time interval T0 which responds with an interval of said position signal; and signal producing means for producing at least an activation control signal which responds with an output signal of said time measuring means, thereby controlling an active operation of at least one power amplifying means among said Q first power amplifying means and said Q second power amplifying means responding with said at least an activation control signal; said signal producing means including: slope means for producing a slope signal whose cyclic interval responds with said time interval T0 of said time measuring means, said slope signal repeating a slope waveform substantially a plural times during one period of said position signal; and shaping means for producing said at least an activation control signal which varies substantially smoothly in at least one of rising and falling slopes responding with said slope signal. <IMAGE>
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