An event that indicates unexpected shutdown of a hard disk drive is determined. The hard disk includes first and second controllers that control respective first and second independently-operable actuators. Each of the actuators has one or more heads that access one or more spinning disks of the hard disk drive. While receiving power for the hard disk drive via back-electromotive force of a motor driven by the one or more spinning disks in response to the event, the first and second controllers independently move the respective first and second actuators to safe positions. In response to determining the first and second actuators are in safe positions, write cache data associated with the first and second controllers is written to a non-volatile memory.

An event that indicates unexpected shutdown of a hard disk drive is determined. The hard disk includes first and second controllers that control respective first and second independently-operable actuators. Each of the actuators has one or more heads that access one or more spinning disks of the hard disk drive. While receiving power for the hard disk drive via back-electromotive force of a motor driven by the one or more spinning disks in response to the event, the first and second controllers independently move the respective first and second actuators to safe positions. In response to determining the first and second actuators are in safe positions, write cache data associated with the first and second controllers is written to a non-volatile memory.

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings. The windings of the spindle motor are commutated based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation. When a supply voltage falls below a threshold while the spindle motor is rotating the disk, the spindle motor is configured into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings. The windings of the spindle motor are commutated based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation. When a supply voltage falls below a threshold while the spindle motor is rotating the disk, the spindle motor is configured into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

A data storage device includes a ramp configured to support at least one head in the data storage device, and a movement mechanism coupled to the ramp and configured to move the ramp from a first position to a second position by at least one of expansion or contraction of at least a portion of the movement mechanism. The data storage device further includes a ramp motion control module operably coupled to the movement mechanism. The ramp motion control module is configured to provide the movement mechanism with a first control signal that causes the movement mechanism to move the ramp from the first position to the second position. The data storage device additionally includes a latch configured to hold the ramp.

A data storage device includes a ramp that supports at least one head, and a retraction mechanism that moves the ramp from a non-retracted position to a retracted position. The movement of the ramp is enabled by at least one of expansion or contraction of at least a portion of the retraction mechanism. The data storage device further includes a ramp retraction control module operably coupled to the retraction mechanism. The ramp retraction control module provides the retraction mechanism with a first control signal that causes the retraction mechanism to move the ramp from the non-retracted position to the retracted position.

In one aspect, a data storage device includes a disc, an arm, a head, a linear driver, and an elevator. The disc has a read/write surface defining an x-y plane. The arm has a head end that is movable relative to the disc. The head is configured to interact with the read/write surface. The linear driver is configured to move the arm along a substantially straight line in the x-y plane. The elevator is configured to move the arm in a z direction. In another aspect, rather than a linear driver, the data storage device includes a rotary actuator and a pivot actuator. The arm includes a first portion and a load beam. The rotary actuator is configured to move the first portion about a first pivot axis; the pivot actuator is configured to move the load beam about a second pivot axis relative to the first portion.

In one aspect, a data storage device includes a disc, an arm, a head, a linear driver, and an elevator. The disc has a read/write surface defining an x-y plane. The arm has a head end that is movable relative to the disc. The head is configured to interact with the read/write surface. The linear driver is configured to move the arm along a substantially straight line in the x-y plane. The elevator is configured to move the arm in a z direction. In another aspect, rather than a linear driver, the data storage device includes a rotary actuator and a pivot actuator. The arm includes a first portion and a load beam. The rotary actuator is configured to move the first portion about a first pivot axis; the pivot actuator is configured to move the load beam about a second pivot axis relative to the first portion.

A load/unload ramp includes a body with ramps, load/unload surfaces, and a vertical wall. The ramps include outer grooves positioned between the ramps. The load/unload surfaces extend from the respective ramps. The vertical wall includes channels extending through the vertical wall. In embodiments, the channels are positioned between the load/unload surfaces.

A load/unload ramp includes a body with ramps, load/unload surfaces, and a vertical wall. The ramps include outer grooves positioned between the ramps. The load/unload surfaces extend from the respective ramps. The vertical wall includes channels extending through the vertical wall. In embodiments, the channels are positioned between the load/unload surfaces.