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. 01, 1990
Filed:
Oct. 04, 1988
Applicant:
Inventor:
John J Freeman, Longmont, CO (US);
Assignee:
MiniScribe Corporation, Longmont, CO (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02K / ; H02P / ;
U.S. Cl.
CPC ...
318254 ; 318138 ; 318431 ;
Abstract
An n-phase, m-pole (wherein n and m are integers) brushless motor is driven without use of physical rotary position detectors, such as Hall elements or the like. An harmonic component of back emf induced in the phases of the motor is detected and used to generate phase energizing signals (such as in response to zero crossings of the detected harmonic component) which, in turn, energize selected phases of the motor. Drive current is supplied to those phases which are energized by the phase energizing signal in predetermined sequence.