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:
Jan. 10, 1989
Filed:
Sep. 30, 1986
Ahmed El-Amawy, Baton Rouge, LA (US);
Ali Mirbod, Baton Rouge, LA (US);
Louisiana State University, Baton Rouge, LA (US);
Abstract
A method of controlling a six pulse bridge phase controlled rectifier using a microprocessor is provided by the invention herein. The method involves synchronizing an oscillator to the frequency of an ac power source and driving first and second counters with the oscillator. The first counter is used in conjunction with a phase locked loop to monitor and adjust the oscillator frequency. The count of the second counter generates an .alpha. value used in a firing angle match routine. The match routine compares the desired output voltage to the cosine of .alpha. minus an inductance factor. The match routine takes less than 20 microseconds to run allowing a new .alpha. value to be checked every 0.5 degrees for a 60 hertz power source. When a match is found, the thyristors are fired and a reload value projecting a subsequent firing in 60.degree. is calculated for the second counter.