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:
May. 17, 1977
Filed:
Jul. 14, 1975
Applicant:
Inventors:
Shashi B Dewan, Toronto, CA;
Robert M Olsen, Barrington, IL (US);
Assignee:
Vapor Corporation, Chicago, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318227 ; 318230 ; 318231 ;
Abstract
A drive circuit for an induction motor used in an air conditioning system of a railway vehicle operable from an applied high voltage direct current, which circuit comprises a chopper circuit having its input connected to the high voltage direct current and its output connected to a three-phase variable frequency inverter circuit which, in turn, has its output connected to the induction motor. A voltage feedback is employed to control the current output of the chopper circuit and the frequency of the inverter circuit.