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. 16, 1987
Filed:
Feb. 28, 1985
Applicant:
Inventor:
Pierre Boillat, Meyriez, CH;
Assignee:
Sodeco-Saia AG, Murten, CH;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318696 ; 318685 ;
Abstract
In an apparatus and method for preventing instability of a stepper motor operated by a plurality of alternating currents of different respective phases and controlled by a sequence of control pulses, the control pulses defining an angular parameter of the stepper motor, the steps include determining the sum of the phase currents, transforming the sum of the phase currents into a voltage fluctuating about an average value, determining the average voltage, and thereafter feeding back the fluctuating voltage so as to angle-modulate said control pulses.