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:
Aug. 28, 2012
Filed:
Nov. 27, 2009
Chin-long Ku, Taipei Hsien, TW;
Chin-wen Yeh, Taipei Hsien, TW;
Zhi-jian Peng, Shenzhen, CN;
Hai-shan Sun, Shenzhen, CN;
Chin-Long Ku, Taipei Hsien, TW;
Chin-Wen Yeh, Taipei Hsien, TW;
Zhi-Jian Peng, Shenzhen, CN;
Hai-Shan Sun, Shenzhen, CN;
Fu Zhun Precision Industry (Shen Zhen) Co., Ltd., Shenzhen, Guangdong Province, CN;
Foxconn Technology Co., Ltd., Tu-Cheng, New Taipei, TW;
Abstract
A control circuit for controlling current through LEDs of an LED lamp includes a voltage regulator, a feedback circuit with an amplifier and a photo-resistor. The voltage regulator includes an output terminal connecting with the LEDs and a feedback terminal. The amplifier includes an in-phase input end coupling with an output end of the LEDs, an out-phase input end and an output end connected to the feedback terminal of the voltage regulator. The photo-resistor is connected between the out-phase input end of the amplifier and the ground. The photo-resistor has a resistance increasing along with a decrease of the light intensity of the LEDs. The increase of resistance of the photo-resistor is fed back to the voltage regulator via the amplifier, to thereby increase the electric current through the LEDs to maintain the light intensity of the LED lamp within an acceptable range.