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. 01, 1997
Filed:
Nov. 10, 1994
Andrew P Weise, Columbia, CT (US);
Donald P Cornell, Manchester, CT (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
A resonant link inverter control for driving a multi-phase induction motor through three feed lines each connected to opposite sides of a DC bus by a pair of switches. A resonant tank circuit connects a source of DC voltage through an inductor to the DC bus and provides a tank capacitor in parallel with the DC bus. A bipolar transistor having an anti-parallel diode, which is in series with a clamp capacitor to form a clamp circuit connected across the tank inductance, is turned off in response to the clamp current bearing a predetermined relationship to voltage across the clamp circuit as well as voltage across the DC source. The current in each feed line is sampled in response to clamp current which is just slightly less than that which causes turnoff of the clamp transistor.