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:
Mar. 27, 2012
Filed:
Oct. 30, 2009
Ruei-jhih Jheng, Hsin-Chu, TW;
Chia-liang Tai, Hsin-Chu, TW;
Ruei-Jhih Jheng, Hsin-Chu, TW;
Chia-Liang Tai, Hsin-Chu, TW;
Young Lighting Technology Inc., Hsin-Chu, TW;
Abstract
A LED driving circuit includes a transformer, a rectifying filtering circuit, a PWM IC, a constant current circuit, and a feedback circuit. The transformer has a primary side and a secondary side. The rectifying filtering circuit is coupled to the secondary side and has a first output terminal. The PWM IC is coupled to the primary side. The constant current circuit has a second output terminal. A LED load is adapted to couple between the first output terminal and the second output terminal. The feedback circuit has a first input terminal coupled to the first output terminal to receive a first voltage and a second input terminal coupled to the constant current circuit to receive a second voltage. The second voltage varies with a conduction status of the LED load. The feedback circuit is adapted to control the PWM IC according to the received first and second voltages.