Disk drive with efficient coil temperature estimation
AssigneeWestern Digital Technologies, Inc.
InventorsCarl R. Messenger, David D. Nguyen
Life of this patent
Estimating the term…
Abstract
A controller for a disk drive that accesses a look up table having a plurality of thermally characterized values corresponding to a plurality of seek operations. For each seek operation, the corresponding value is added to a register. The controller decrements the register at a rate that is determined using servo interrupts occurring as a result of the rotation of the disk. When the value of the register exceeds a threshold, the controller adjusts the subsequent seek operation so as to inhibit damage to the voice coil as a result of overheating.
Claims47
A method of inhibiting a voice coil of a hard disk drive from overheating, the method comprising:
- performing a plurality of seek operations;
- adjusting a value stored in a register by amounts which are indicative of the heat which is produced in the voice coil during the plurality of seek operations;
- continually counter-adjusting the adjusted value stored in the register while the plurality of the seek operations are performed, wherein the counter-adjusting occurring at a rate which is determined by a substantially periodic signal;
- and
- modifying seek operations when the value of the register is outside of a preferred range.
A method of inhibiting a voice coil of a hard disk drive from overheating, the method comprising:
- performing a plurality of seek operations so as to reposition a transducer adjacent a recording medium a plurality of times, wherein each seek operation adds heat to the coil;
- determining a plurality of thermally characterized values, wherein each thermally characterized value is indicative of the heat that is added to the coil during a corresponding seek operation of the plurality of seek operations;
- accumulating the plurality of thermally characterized values in a register;
- continually reducing the value stored in the register while the plurality of the seek operations are performed;
- and
- modifying seek operations when the value of the register is greater than a threshold value.
A hard disk drive comprising:
- a magnetic medium;
- a transducer that interacts with the magnetic medium;
- an actuator comprising a voice coil that accelerates the transducer;
- and
- a control system comprising a register, wherein the control system instructs the actuator to perform a plurality of seek operations so as to reposition the transducer between a plurality of locations adjacent the magnetic medium, wherein the register stores a value which is indicative of the thermal energy of the coil, wherein the control system adjusts the value of the register according to the plurality of seek operations so as to account for heat added to the coil during the plurality of seek operations, wherein the control system continually counter-adjusts the adjusted value of the register while the plurality of the seek operations are performed to account for heat that dissipates away from the coil, and wherein the control system modifies subsequent seek operations when the value stored in the register is outside of a preferred range so as to reduce the rate at which heat is added to the coil.
Dependencies are inferred from the claim text.