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:
Feb. 01, 1983
Filed:
Oct. 15, 1980
Applicant:
Inventor:
Martyn A Lewis, Pacific Palisades, CA (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318313 ; 318317 ; 318342 ; 318388 ;
Abstract
A control system for a brushless direct current motor providing linear closed loop speed control when the motor is operating near its desired speed and providing pulse width modulation closed loop speed control when the motor is not operating near its desired speed. A current sensing feedback loop is provided to drive the transistor linearly controlling the electronic commutation of the motor into pulse width modulation when the current through the motor exceeds a predetermined value. An inductor may be coupled in series with control transistor and positive feedback may be supplied to the current sensor.