Disk drive employing active braking using inductive sense
AssigneeWestern Digital Technologies, Inc.
InventorRobert P. Ryan
Life of this patent
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Abstract
A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. Disk control circuitry executes a spin-down operation of the spindle motor by estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding. The windings are commutated in response to the estimated angular position, and a driving current is applied to the windings to brake the spindle motor.
Claims12
A disk drive comprising:
- (a) a disk;
- (b) a head actuated over the disk;
- (c) a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings configurable into a plurality of commutation states;
- and
- (d) disk control circuitry for executing a spin-down operation of the spindle motor by:
- estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding;
- configuring the windings into a selected one of the commutation states in response to the estimated angular position;
- and
- applying a driving current to the windings of the selected commutation state to brake the spindle motor.
A method of spinning down a disk drive, the disk drive comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings configurable into a plurality of commutation states, the method comprising:
- (a) estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding;
- (b) configuring the windings into a selected one of the commutation states in response to the estimated angular position;
- and
- (c) applying a driving current to the windings of the selected commutation state to brake the spindle motor.
Dependencies are inferred from the claim text.