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. 09, 2010
Filed:
Dec. 12, 2007
Cheng-chang Yang, Taoyuan, TW;
Guang-ming Lei, Taoyaun, TW;
Yu-chi Lai, Taoyuan, TW;
Asian Power Devices Inc., Taoyuan, TW;
Abstract
A light emitting diode (LED) circuit having even current has multiple LED strings, a current equalizing integrated circuit (IC) and a voltage compensation module. The LED strings are connected to an external power source, and each LED string has a power terminal and a driving terminal. The current equalizing IC has multiple driving pins connected respectively to the driving terminals of the LED strings. The voltage compensation module is connected between the LED strings and the external power source and has a threshold voltage value and multiple input terminals. The input terminals are connected respectively to the driving pins of the current equalizing IC to allow the voltage compensation module rise and send the voltage obtained from the external power source to the LED strings when the voltage compensation module determines any voltage on the driving pins of the current equalizing IC is lower than the threshold voltage value.