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:
Jan. 04, 2005
Filed:
May. 28, 2002
Applicants:
Corneliu Dragoi, Ontario, CA;
Rodney Vanwyck, Ontario, CA;
Inventors:
Corneliu Dragoi, Ontario, CA;
Rodney Vanwyck, Ontario, CA;
Assignee:
Siemens VDO Automotive Inc., Mississauga, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P 700 ;
U.S. Cl.
CPC ...
Abstract
A method of detecting a rotor condition of a dc motor is provided. The motoris part of a motor control circuithaving a free-wheeling diodein parallel with the motor. The method establishes a threshold voltage for back emf voltage evaluation. The motor is energized to operate at a certain speed. Current is cut-off to the motor via a switchfor a time sufficient for current through the free-wheeling diode to decay to zero. The back emf voltage detected at leads of the motor is then compared via a comparatorto the threshold voltage.