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:
Dec. 11, 2001
Filed:
Feb. 29, 2000
Alan Starkie, Los Altos, CA (US);
Nickolas G. Vrionis, Los Altos, CA (US);
Gas Research Institute, Chicago, IL (US);
Abstract
A commercial application for a four-step switching PWM single phase AC controller for a load such as an induction motor or the like has a digital microcontroller for PWM signal generation and enhanced MOSFET switching control, and provides a multiplicity of discrete speed settings to make any single phase AC driven device easily and cheaply converted to efficient variable speed operation. Only two MOSFET gate drive optocouplers are provided on the high side of line voltage for reduced cost. Series transistors are programed to be left full on at maximum motor speed for increased efficiency. Current limit and under voltage sensing for fault protection are provided.