Electrical phase compensation in BEMF spindle motor control
First Claim
1. A method comprising the steps of:
- determining a speed of a motor;
determining a compensation value based on a phase of the motor, wherein the compensation value is a value that compensates for asymmetrical electrical phases of the motor;
generating a control signal based on the speed of the motor, the compensation value and a reference speed; and
providing the control signal to the motor to thereby control the speed of the motor.
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Accused Products
Abstract
A method and apparatus for compensating for the asymmetrical phases of a spindle motor in a disc drive are provided. With the apparatus and method, compensation values are learned by sampling speed data during a period of operation of the disc drive where the speed is stable and only one control operation is performed per revolution of the disc. The sampled speed data is used to generate the compensation values for each of the phases of the spindle motor. The compensation values are stored in a compensation mechanism which is used by the spindle motor speed controller to provide compensation for the asymmetrical phases of the spindle motor. During Normal operation, the actual speed output of the spindle motor is measured and is subtracted from a reference speed to generate a difference speed value. Based on the corresponding electrical phase, the correct compensation value is fetched and is subtracted from the difference speed value to obtain a compensated difference speed value. A control signal based on this compensated difference speed value is generated and provided to the spindle motor to thereby control the output speed of the spindle motor.
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Citations
20 Claims
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1. A method comprising the steps of:
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determining a speed of a motor;
determining a compensation value based on a phase of the motor, wherein the compensation value is a value that compensates for asymmetrical electrical phases of the motor;
generating a control signal based on the speed of the motor, the compensation value and a reference speed; and
providing the control signal to the motor to thereby control the speed of the motor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus comprising:
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a motor a measuring device for measuring the speed of the motor;
a controller coupled to the motor; and
an asymmetrical phase compensation device coupled to the controller, wherein the measuring device of the motor determines a speed of the motor, the asymmetrical phase compensation device determines a compensation value based on a phase of the motor, the compensation value being a value that compensates for asymmetrical electrical phases of the motor, and wherein the controller generates a control signal based on the speed of the motor, the compensation value and a reference speed and provides the control signal to the motor to thereby control the speed of the motor. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification