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:
Aug. 25, 1981
Filed:
Jul. 16, 1979
Douglas E Clancy, Austin, TX (US);
Richard F Frankeny, Elgin, TX (US);
George P Olson, Austin, TX (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
A damping control system for a three phase stepper motor. A reluctance velocity transducer is used for each of the three phases. The output of each of the transducers is proportional to the rotational velocity of the motor. Each of the transducers is rotationally phase shifted 3.75 with respect to one another and phased to the motor rotor rotationally such that the zero voltage crossings of the transducers correspond to the zero torque crossings of the motor. During damping or detenting of the motor the selected phase has current applied to it which is equal to a predetermined fixed value plus the feedback from its associated transducer. The windings on each side of the detent position have current applied to them which is proportional to the voltage from their respective feedback transducers. The voltage in each of the windings is amplified by a selected gain constant. The current in each of the windings is such that maximum torque is applied to drive the motor to the detent position with appropriate current reversals in the windings to damp out any kinetic energy in the rotor during detenting.