Spindle motor back-EMF synchronous rectifier
AssigneeTexas Instruments Incorporated
InventorChing-Siang Chen
Life of this patent
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Abstract
A disk drive system including a disk having a magnetic surface and suppported for rotation on a spindle, a magnetic head being movable relative to the magnetic surface, and a spindle motor for driving the spindle. The motor generates a back-EMF voltage during an emergency condition and switches said back-EMF voltage during said emergency condition. A comparator circuit compares different phases of back-EMF voltage, and a control circuit controls said plurality of switches to supply said back-EMF voltage to direct said head to a stored position.
Claims8
A disk drive system, said system including a disk having a magnetic surface and supported for rotation on a spindle, a magnetic head being movable relative to said magnetic surface, and a spindle motor for driving said spindle, said system comprising:
- said motor generating a back-EMF voltage during an emergency condition;
- a plurality of switches for switching said back-EMF voltage during said emergency condition;
- a comparator circuit for comparing different phases of back-EMF voltage;
- and
- a control circuit to control said plurality of switches to supply said back-EMF voltage to direct said head to a stored position.
A method for operating a disk drive system, said system including a disk havig a magnetic surface and suppported for rotation on a spindle, a magnetic head being movable relative to said magnetic surface, and a spindle motor for driving said spindle, said method including the steps of:
- generating a back-EMF voltage from said motor during an emergency condition;
- switching said back-EMF voltage during said emergency condition;
- comparing different phases of said back-EMF voltage;
- and
- controlling said plurality of switches to supply said back-EMF voltage to direct said head to a stored position.
Dependencies are inferred from the claim text.