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:
Sep. 14, 1993
Filed:
Nov. 09, 1992
Applicant:
Inventors:
Alain M Cassat, Pully, CH;
Laurent Cardoletti, Montreux, CH;
Assignee:
Seagate Technology, Inc., Scotts Valley, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
318254 ; 318138 ; 318439 ; 388815 ; 3889281 ;
Abstract
A brushless DC motor control apparatus and method for regulating the speed of a motor at a nominal speed. The apparatus maintains a nominal motor speed without the use of conventional rotor position location devices such as Hall sensors. The current speed of the motor is determined using the back EMF zero-crossing measured only on complete rotor revolutions to mitigate motor dissymmetry errors. A control system compares the current speed to a desired speed and adjusts the total motor current to attain the desired speed. As a result, highly accurate speed control is maintained.