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:
Jan. 28, 2014
Filed:
Dec. 28, 2010
Yiyoung Tony Sun, Beverly, MA (US);
Kenichi Fukuda, Burlington, MA (US);
Yiyoung Tony Sun, Beverly, MA (US);
Kenichi Fukuda, Burlington, MA (US);
Universal Lighting Technologies, Inc., Madison, AL (US);
Abstract
A lamp ballast is provided for igniting and operating an HID lamp. A buck inverter circuit includes a pair of high-frequency and a pair of low-frequency switches. A capacitor and an inductor are series-connected between a first node between the low frequency switches and a second node between the high frequency switches. A lamp igniting circuit is coupled between the first node and a first lamp output terminal, and a second lamp output terminal is coupled to a third node between the capacitor and the inductor. A control circuit turns on and off the switches to regulate low frequency square wave voltage generated across the lamp output terminals to be less than an input DC voltage from the positive rail, wherein the buck inverter operates in either of a critical discontinuous mode or a discontinuous mode during an open circuit operation, and in a critical discontinuous mode during other operations.