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:
Apr. 30, 1985
Filed:
Apr. 26, 1983
Walter H Sakmann, Nufringen, DE;
Volker Zimmermann, Sindelfingen, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Method and apparatus for the constant speed control of a brushless DC motor, whose pole windings receive a pulsed control voltage between their commutation points, control being a function of the speed characteristics of the motor, and the commutation points being synchronized with the drop times of the motor current and the control voltage pulses. In a state in which there are no load changes, the motor current substantially rises or drops between a maximum value I.sub.max and a minimum value I.sub.min according to the pulse mode. In the event of changes in the motor load, a mean motor sum current is retained for maintaining the speed.