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US 7,095,195 B2Granted
Motor and disk drive apparatus
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMasaki Tagome, Hideaki Mori, Hisanori Nagase, Makoto Gotou
Life of this patent
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Abstract
In a motor and a disk drive apparatus in accordance with the present invention, a position detecting part 30 comprises a detection signal switching circuit 39A, a noise elimination circuit 38 and a detection circuit 39B, and the detection signal switching circuit 39A is configured to output an inverted detection signal obtained by logically inverting a detection signal until the rotation speed reaches a predetermined rotation speed after the beginning of starting or until a position detection pulse signal FG is detected a predetermined number of times; position detection operation is carried out only during the ON operation of PWM, whereby PWM sensorless starting is carried out.
Claims15
A motor comprising:
- a rotor;
- windings of a plurality of phases;
- power supplying means, including a plurality of first drive power transistors and a plurality of second drive power transistors, for supplying electric power to said windings of a plurality of phases;
- position detecting means for detecting the rotation position of said rotor in response to the terminal voltages of said windings of a plurality of phases;
- activation controlling means for controlling activation to said windings of a plurality of phases by said power supplying means in response to a position signal output from said position detecting means;
- commanding means for outputting a speed command signal;
- and
- switching operation means for causing at least one of said plurality of first drive power transistors and said plurality of second drive power transistors of said power supplying means to perform high-frequency switching operation in response to said speed command signal;
- and that said position detecting means is provided with position detection signal switching means that carries out switching between a detection signal for detecting the rotation position of said rotor and an inverted detection signal generated by inverting the logic of said detection signal and outputs the obtained signal in response to voltage comparison signals obtained by a comparison of outputs between each of the terminal voltages of said windings of non-activation phases and the neutral point voltage of the common potential of said windings of a plurality of phases,
- the output signal of said position detection signal switching means is used as said position signal during the ON operation of said high-frequency switching operation, and
- said position detection signal switching means outputs said inverted detection signal as said position signal at the beginning of starting.
8 more elements
A disk drive apparatus comprising:
- head means for at least carrying out signal reproduction from a disk or carrying out signal recording on said disk;
- information processing means for at least processing the output signal of said head means and outputting a reproduced information signal or processing and outputting a recorded information signal to said head means;
- a rotor for directly rotating and driving said disk;
- windings of a plurality of phases;
- power supplying means, including a plurality of first drive power transistors and a plurality of second drive power transistors, for supplying electric power to said windings of a plurality of phases;
- position detecting means for detecting the rotation position of said rotor in response to the terminal voltages of said windings of a plurality of phases;
- activation controlling means for controlling activation to said windings of a plurality of phases by said power supplying means in response to a position signal output from said position detecting means;
- commanding means for outputting a speed command signal;
- and
- switching operation means for causing at least one of said plurality of first drive power transistors and said plurality of second drive power transistors of said power supplying means to perform high-frequency switching operation in response to said speed command signal;
- and that said position detecting means is provided with position detection signal switching means that carries out switching between a detection signal for detecting the rotation position of said rotor and an inverted detection signal generated by inverting the logic of said detection signal and outputs the obtained signal in response to voltage comparison signals obtained by a comparison of outputs between each of the terminal voltages of said windings of non-activation phases and the neutral point voltage of the common potential of said windings of a plurality of phases,
- the output signal of said position detection signal switching means is used as said position signal during the ON operation of said high-frequency switching operation, and
- said position detection signal switching means outputs said inverted detection signal as said position signal at the beginning of starting.
10 more elements
Dependencies are inferred from the claim text.