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:
May. 23, 1995
Filed:
Aug. 19, 1993
Nickolas C Apuzzo, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for starting and operating an electric motor such as the spindle motor of a disk drive assembly employs a segmented stator winding. On startup, the winding segments are connected in series in order to maximize torque. Motor speed is detected, and when a predetermined speed is reached, the segments are connected in parallel to reduce the effective number of winding turns and maintain a control voltage for motor speed control. Switching of the winding segments can be by active elements such as FETs or by passive reactive elements responding directly to motor speed. For more gradual motor torque constant control, the winding may have more than two segments.