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. 06, 2008
Filed:
Sep. 28, 2006
Jea-sen Lin, Taipei County, TW;
Ta-yung Yang, Milpitas, TW;
Jea-Sen Lin, Taipei County, TW;
Ta-yung Yang, Milpitas, TW;
System General Corp., Taipei Hsien, TW;
Abstract
A lower-cost ballast circuit for fluorescent lamps is provided. A resonant circuit is formed by a series connection of an inductor and a capacitor to operate the fluorescent lamp. A first circuit and a second circuit are coupled to switch the resonant circuit. Taking the first circuit for instance, a first resistor is connected in series with a first switch for generating a first control signal in response to a switching current of the first switch. The first switch is turned on once the first control signal is lower than a first zero-threshold. After a quarter resonant period of the resonant circuit, the first switch is turned off once the first control signal is lower than a first threshold. Therefore, a soft switching for the first switch is achieved.