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. 19, 1980
Filed:
Dec. 18, 1978
George S Chambers, Daleville, VA (US);
General Electric Company, Salem, VA (US);
Abstract
In association with a polyphase rectifying bridge having controlled rectifiers there is employed, in addition to the normal means for controlling the firing time of the controlled rectifiers, additional circuitry for preventing the occurrence of a commutation fault. This is achieved by first producing a timing signal representative of the time intervals during which a commutation between successively fired controlled rectifiers of the bridge actually exist. This timing signal, after being properly shaped is combined with a basic reference signal representative of a predetermined value to which the rectifiers may be phased back in their firing angle without resulting in a commutation failure. Stated in another way, the width of the existing commutation period serves to set a minimum to which the next commutation period must conform. When the prescribed relationships exist between the timing signal and the basic reference signal, the normal control means is overriden and the firing angle of the controlled rectifier is advanced to a point which will insure commutation.