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:
Jun. 26, 2001
Filed:
Nov. 23, 1999
Applicant:
Inventors:
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K 2/300 ; H02P 1/18 ; H02P 3/08 ; H02P 5/06 ; H02P 7/06 ;
U.S. Cl.
CPC ...
H02K 2/300 ; H02P 1/18 ; H02P 3/08 ; H02P 5/06 ; H02P 7/06 ;
Abstract
A method and circuit for operating a polyphase dc motor in which discontinuous sinusoidal drive voltages are applied to the windings of the motor in predetermined phases. The discontinuous portion of the sinusoid is timed with the bemf zero crossings. Bemf zero crossings are detected, and phases of the drive voltages are adjusted to have zero crossings substantially in the discontinuities of the drive voltages. The method and circuit result in motor operation with significantly reduced acoustic motor noise.