Servo writer with retract capacitor for generating a VCM driving current during a power failure
AssigneeWestern Digital Technologies, Inc.
InventorsPuspanathan Krishnan, Anandan Vengadasalam
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Abstract
A servo writer is disclosed for writing servo data onto a disk of a disk drive. The servo writer comprises a push-pin operable to contact an actuator arm of the disk drive, an actuator for actuating the push pin, and a retract capacitor. The retract capacitor is charged, and the actuator actuates the push-pin in order to position the head radially over the disk. If a power failure occurs while actuating the push-pin, a current is applied from the retract capacitor to a voice coil of the actuator arm in order to retract the actuator arm.
Claims20
A servo writer for writing servo data onto a disk of a disk drive, the servo writer comprising:
- a push-pin operable to contact an actuator arm of the disk drive, wherein the actuator arm comprises a voice coil coupled to a base of the actuator arm and a head coupled to a distal end of the actuator arm;
- an actuator for actuating the push-pin;
- a retract capacitor;
- and
- control circuitry operable to apply a current from the retract capacitor to the voice coil in order to retract the actuator arm if a power failure occurs while actuating the push-pin;
- wherein:
- the control circuitry comprises a voltage regulator for generating a regulated voltage in response to the retract capacitor, where the regulated voltage is applied across the voice coil to generate the current applied to the voice coil;
- the voltage regulator is configurable to apply a maximum current to the voice coil selected from a plurality of possible maximum currents;
- and
- the maximum current is selected based on a type of disk drive being servo written.
A method for writing servo data onto a disk of a disk drive, wherein the disk drive comprises an actuator arm including a voice coil coupled to a base of the actuator arm and a head coupled to a distal end of the actuator arm, the method comprising:
- actuating a push-pin to move the actuator arm;
- applying a current from a retract capacitor to the voice coil in order to retract the actuator arm if a power failure occurs while actuating the push-pin;
- and
- generating a regulated voltage in response to the retract capacitor, where the regulated voltage is applied across the voice coil to generate the current applied to the voice coil;
- wherein:
- the regulated voltage is generated to apply a maximum current to the voice coil selected from a plurality of possible maximum currents;
- and
- the maximum current is selected based on a type of disk drive being servo written.
A servo writer for writing servo data onto a disk of a disk drive, the servo writer comprising:
- a push-pin operable to contact an actuator arm of the disk drive, wherein the actuator arm comprises a voice coil coupled to a base of the actuator arm and a head coupled to a distal end of the actuator arm;
- an actuator for actuating the push-pin;
- a retract capacitor;
- control circuitry operable to apply a current from the retract capacitor to the voice coil in order to retract the actuator arm if a power failure occurs while actuating the push-pin;
- and
- a plurality of switches for configuring a direction of the current applied to the voice coil, thereby configuring a retract direction of the actuator arm.
A method for writing servo data onto a disk of a disk drive, wherein the disk drive comprises an actuator arm including a voice coil coupled to a base of the actuator arm and a head coupled to a distal end of the actuator arm, the method comprising:
- actuating a push-pin to move the actuator arm;
- applying a current from a retract capacitor to the voice coil in order to retract the actuator arm if a power failure occurs while actuating the push-pin;
- and
- selecting a direction of the current applied to the voice coil, thereby configuring a retract direction of the actuator arm.
Dependencies are inferred from the claim text.