05397971 is referenced by 24 patents and cites 12 patents.

A multiple pole, multiple phase, sensorless DC disk spindle motor in a disk drive is powered by direct current which is commutated among the motor phases from a DC power supply to start the motor and to rotate the disks at constant speed in a predetermined direction whenever the disk drive is in use. When the motor is prevented from rotating by the stiction bond of one or more transducers which have adhered to the disks, the direct current is reversibly commutated among the motor phases near the resonant frequency, a predetermined number of times, to produce substantially sinusoidal, bi-polar motor torques to achieve torque amplification to break the stiction bonds. Following the last of the predetermined number of reversible commutations of direct current, direct current commutation is initiated among the motor phases to rotate the motor and the disks in the desired direction at constant speed.

Title
Bi-polar disk torquing system for a disk drive to free stuck transducers
Application Number
895495
Publication Number
5397971
Application Date
July 13, 1994
Publication Date
March 14, 1995
Inventor
Henricus M van Hout
PP Heeze
NL
Boyd N Shelton
Boise
ID, US
Jeffrey S McAllister
Boise
ID, US
Agent
E F Oberheim
Assignee
Hewlett Packard Company
CA, US
IPC
G11B 21/02
H02P 6/02
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