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. 13, 1996
Filed:
Sep. 16, 1993
International Business Machines Corporation, Armonk, NY (US);
Abstract
Automatic start up of a continuous sine-wave commutated, brushless, direct current motor in a predetermined direction is done by applying a ramped armature current to the direct current motor to generate an armature field. The resulting armature field is rotated independent of angular position of the shaft. Upon rotation of the motor shaft beginning, the direction of rotation of the shaft is determined. Responsive to rotation of the shaft in an undesired direction, the direction of rotation of the armature field is reversed. A base angle of rotation of a shaft in the direct current motor is determined from an index mark as it rotates by an index mark detector. Responsive to detection of the index mark, rotation of the armature field and the angular position of the shaft are synchronized.