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. 22, 1983
Filed:
Feb. 17, 1982
Alan L Husson, Hackettstown, NJ (US);
Vladimir Uherek, Parsippany, NJ (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
An elevator system including an elevator car and a drive machine having a DC drive motor, a dual converter, and a phase controller for providing gate drive signals for the dual converter. A reference signal relates to the desired motor armature current is developed in response to the operation of the elevator system. The reference signal indicates when the current source should be switched from one converter bank to the other converter bank. The switching is accomplished by a method which includes retarding the firing angle of the gate drive signals applied to the operative converter, until current is extinguished, applying the gate drive signals to the other converter bank, and advancing the firing angle towards rectification to initiate current flow in the on-coming converter. The rate at which the firing angle is advanced towards rectification is a function of the control signal.