The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 15, 2000
Filed:
Feb. 23, 1999
Raffi Codilian, San Dimas, CA (US);
Steven Nemshick, Santa Ana, CA (US);
Robert P Ryan, Coto de Caza, CA (US);
Western Digital Corporation, Irvine, CA (US);
Abstract
A disk drive employs a method of operating a spindle motor to respond to a spin-down command to reduce the time required for spinning down and subsequently spinning up the spindle motor. The disk drive is connectable to a power supply having a fixed DC voltage. The spindle motor includes a stator having a plurality of windings and a rotor rotatable at a variable spin-rate. The rotor has an angular position relative to the stator. The disk drive includes switching elements coupled to the fixed DC voltage and the plurality of windings. The switching elements are controlled to sequentially apply the fixed DC voltage across a selected combination of the windings to generate a negative torque on the rotor such that a controlled braking operation is performed to decelerate the rotor to a selected spin-rate .omega.1. After the variable spin-rate is reduced to the selected spin-rate .omega.1, the switching elements are controlled to apply the fixed DC voltage across at least one of the windings such that a controlled rotor-stopping operation is performed to control the angular position of the rotor when the rotor comes to a stop at the end of the controlled rotor-stopping operation.