Seagate Technology Incorporated

Magnetic Peripherals Inc.

Garry Edward Korbel

Christopher L Hill

Andrew Robert Motzko

Hakam D Hussein

Brian Robert Pollock

Stuart Kevin Francis

John M Baker

Matthew Edward Hastings

Donald Ray Bloyer

Ralph James Knotts

Jonathan E Hall

Ranjeet K Pancholy

Mark Brunner

A motor current control method is provided to reduce voltage and current spikes within a spindle motor and a power supply. Subsequently, the amount of current applied to the spindle motor is monitored. In addition, an apparatus for limiting motor power is provided.

Power supply output control apparatus and method

Systems and methods are provided through which the current to a spindle motor of the recording medium of a mass storage device is modulated to avoid anomalies in the operation of mass storage device and reduce power consumption. In the example of a disc drive, the current is modulated to prevent expected or predicted disturbances in the air bearing between a read/write head and the recording medium, and to reduce the power consumption when no disturbances are predicted or expected.

Systems, apparatus, and methods for motor control

A magnetic flux shield extending substantially the entire width of a magnetic disk drive spindle motor magnet is mounted between the magnet and the disk drive's base frame and rotates with the magnet. The flux shield is formed of a magnetic material to capture any stray magnetic flux from the motor magnet that may produce power draining eddy currents in the base frame.

Apparatus for reducing spindle motor magnetic drag

An apparatus and associated method used to control a disc drive having at least one disc and a transducer positionable relative to the disc by a motor. The motor receives energization through at least one power switch integrated on a semiconductor circuit. Temperature of the circuit is sensed proximate the power switch. A temperature signal is provided which is indicative of whether the sensed temperature meets one of a plurality of different threshold temperatures. The power switch is controlled in one of a plurality of different control modes based upon the temperature signal.

Thermal performance of an integrated amplifier in a disc drive

A disc drive comprises a drive motor mechanically coupled to a disc and a voice coil motor mechanically coupled to a read/write head on the disc. A power integrated circuit is electrically coupled to the drive motor and the voice coil motor. The power integrated circuit includes an integrated temperature sensor that provides a temperature output. A control circuit receives the temperature output and provides a voice coil motor control output to the power integrated circuit as a function of the temperature output.

Optimizing thermal performance of an integrated circuit in a disc drive

A disc drive includes an apparatus for limiting coil energization current to a programmable value. A current sensor is operatively coupled to a coil and provides a signal which is indicative of current flow through the coil. A configurable voltage source is responsive to a control signal. A current inhibitor is operatively coupled to the output of the current sensor and the voltage source such that the current inhibitor selectively inhibits current flow through the coil based on results of a comparison between the current sensor signal and a voltage supplied by the configurable voltage source. A method of calibrating a current control threshold is also provided as well as a method of controlling the coil energization current.

Disc drive spindle motor with programmable current control

A motor control circuit controls a motor in a disc drive. The motor control circuit includes a voltage controlled oscillator (VCO) providing a commutation timing signal. A commutation circuit is operably coupled to the VCO and provides commutation signals to the motor based on the commutation timing signal. A phase locked feedback circuit is operably coupled to the commutation circuit and provides a feedback signal to the VCO based on a sensed commutation phase to control a frequency of the commutation timing signal. A modulator is operably coupled to the phase locked feedback circuit and modulates the feedback signal. A method is also provided in which the commutation timing signal is modulated so as to spread a frequency spectrum of the commutation signals.

Circuit and method for modulating the commutation frequency of a disc

A motor control circuit controls a motor in a disc drive is provided. The motor control circuit includes a commutation circuit which provides commutation signals to the motor to commutate the motor at a commutation frequency. A frequency modulation circuit is operably coupled to the commutation circuit. The frequency modulation circuit provides a modulation signal which frequency modulates the commutation frequency according to a predetermined pattern.

Method and apparatus for controlling a motor in a disc drive by

Two data-free tracks, a takeoff zone and a landing zone, are provided on a magnetic disc, in order to provide a place for the magnetic head to come in contact with the disc without risk of destruction of data. An actuator controller places the head on the takeoff zone at the start of the disc's rotation and on the landing zone at the finish of the disc's rotation. Wear caused by contact of the head with the disc is thereby distributed over two zones, which prolongs the life of the disc.

Disc drive with separate landing and takeoff zones

A disc drive includes a stationary frame and vertical spindle shaft, and a hub rotatable relative to the spindle shaft and supporting one or more magnetic discs. A motor for rotating the hub includes an annular stator integrally secured to the spindle shaft, and a rotor assembly integral with the hub. The rotor assembly includes an annular magnet and an annular back iron, with the magnet being spaced apart from the stator to define an air gap. The magnet includes four longitudinally disposed arcuate poles of equal size, separated from one another by flux gaps. Each of the poles has a medial region and first and second end regions on opposite sides of the medial region. The medial region is selectively magnetized to a level less than the level to which the end regions are magnetized, creating a flux gap and torque profile for the magnet particularly effective in reducing torque ripple.

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New Prague, MN, United States of America

Garry Edward Korbel