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:
Oct. 22, 2013
Filed:
Apr. 28, 2011
Sheng Tai Lee, Taipei, TW;
Yung Lin Lin, Palo Alto, CA (US);
Chuan Chiung Kuo, Taipei, TW;
O2Micro, Inc., Santa Clara, CA (US);
Abstract
Embodiments in accordance with the present invention provide circuits and methods for driving a light-emitting diode (LED) light source. In one embodiment, a printed circuit board (PCB) includes a bridge rectifier rectifying an AC voltage to a rectified AC voltage, an LED light source, and a first switch coupled to the LED light source in series controlling a current through the LED light source according to a predetermined current reference. The LED light source and the first switch coupled in series receive the rectified AC voltage while the first switch is controlled linearly. The circuit further includes a current path coupled in parallel with the LED light source and an illuminated switch coupled between the AC power source and the bridge rectifier.