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:
Nov. 20, 1990
Filed:
Mar. 20, 1989
Applicant:
Inventor:
David J Morris, Mayfield Heights, OH (US);
Assignee:
Allen-Bradley Company, Inc., Milwaukee, WI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08C / ; G05B / ;
U.S. Cl.
CPC ...
340870250 ; 318661 ; 318605 ; 340870370 ;
Abstract
A resolver driver circuit uses sine and cosine values stored in a read only memory to generate sine and cosine waveforms by sequentially reading the stored values and passing them through a clocked data latch to a digital-to-analog converter. The output of the digital-to-analog converter is filtered to remove quantization error. Phase error produced by the filtering and other sources is detected by timing the zero crossings of the sine and cosine waveforms and comparing them to a master synchronization signal. Phase error is corrected by controlling the timing of the latch which passes data to the digital-to-analog converter.