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:
Mar. 23, 1976
Filed:
Sep. 13, 1974
Arnold W Feld, Mendota, IL (US);
Conco Inc., Mendota, IL (US);
Abstract
An induction motor is coupled to a three-phase AC source through thyristors controlled by a digital control circuit. An adjustable device gates a selected number of clock pulses to a control counter. As one of the AC phases goes positive, the control counter is incremented or decremented by clock pulses until reaching a predetermined count, which causes a trigger means to generate a trigger pulse and fire a thyristor. The trigger pulse also gates clock pulses to a second control counter which counts to 120.degree. and 240.degree. representing numbers in order to fire the other thyristors. In a speed feedback embodiment, rotation of the motor generates a motor feedback signal which is compared with a desired speed signal to adjust the count of an up/down counter, the contents of which are loaded into the control counter.