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US 2007/0176569 A1Published application
System and method for establishing spindle motor current during cold temperature operation of HDD
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsFarzin Assar, Lee Nguyentran, Phong Vu
Life of this patent
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Abstract
When a HDD is operating at a temperature below a threshold, a partial sine wave is input to the spindle motor to activate the motor to reduce undesirable speed oscillations of the motor. At normal operating temperatures a full since wave is input for noise reduction.
Claims23
A controller chip for a hard disk drive having at least one disk rotated by at least one spindle motor, comprising logic embodying method acts comprising:
- receiving a signal that varies with temperature;
- and
- based on the signal, determining whether to input a full sine wave drive current to the spindle motor.
A data storage device comprising:
- at least one storage disk;
- at least one spindle motor turning the disk;
- at least one spindle driver supplying input drive current to the spindle motor;
- and
- means for causing the driver to configure the drive current as a full sine wave under a first condition, and causing the driver to configure the drive current as a partial sine wave under a second condition.
2 more elements
A disk drive, comprising:
- a micro processor establishing a spindle motor input current profile to be other than full sinusoidal when a signal received by the micro processor indicates that a temperature of the disk drive is below normal operating temperature such that a phase detect window results that is relatively longer than it would be were a full sinusoidal profile to be used for the input current.
Dependencies are inferred from the claim text.