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:
Dec. 17, 2013
Filed:
Jun. 29, 2011
Wenli Yang, Los Angeles, CA (US);
Philip Tin Yue NG, Anaheim, CA (US);
Ashok K. Desai, Westlake Village, CA (US);
Robert P. Ryan, Mission Viejo, CA (US);
Wenli Yang, Los Angeles, CA (US);
Philip Tin Yue Ng, Anaheim, CA (US);
Ashok K. Desai, Westlake Village, CA (US);
Robert P. Ryan, Mission Viejo, CA (US);
Western Digital Technologies, Inc., Irvine, CA (US);
Abstract
A disk drive is disclosed comprising a head actuated over a disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. During a spin-up operation a sinusoidal driving voltage is applied to each winding of the spindle motor. A back electromotive force (BEMF) voltage generated by at least one of the windings is measured, and a rotation speed of the spindle motor is measured. The sinusoidal driving voltage is adjusted in order to optimize a lead angle relative to the rotation speed, wherein the lead angle represents a degree the sinusoidal driving voltage leads the BEMF voltage.