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:
Apr. 14, 1992
Filed:
Oct. 31, 1990
Applicant:
Inventors:
Masao Iwasa, Chiba, JP;
Hirofumi Sugiura, Aichi, JP;
Assignee:
Otis Elevator Company, Farmington, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02M / ;
U.S. Cl.
CPC ...
363 98 ; 363132 ; 318811 ;
Abstract
The DC offset in a current control system for a PWM inverter drive is corrected by integrating a DC component of a current control signal provided by a current control amplifier and feedback controlling the current control amplifier to reduce the DC component to zero.