Invention Grant
- Patent Title: Method and apparatus for controlling brightness of light emitting diodes
- Patent Title (中): 用于控制发光二极管亮度的方法和装置
-
Application No.: US12949684Application Date: 2010-11-18
-
Publication No.: US08928241B2Publication Date: 2015-01-06
- Inventor: Chung Ping Kevin Lo , Kwok Hung Poon , Wa-Hing Leung , Kam Wah Siu
- Applicant: Chung Ping Kevin Lo , Kwok Hung Poon , Wa-Hing Leung , Kam Wah Siu
- Applicant Address: CN Huizhou, Guangdong
- Assignee: Huizhou Light Engine Ltd.
- Current Assignee: Huizhou Light Engine Ltd.
- Current Assignee Address: CN Huizhou, Guangdong
- Agency: Schiff Hardin LLP
- Main IPC: H05B37/02
- IPC: H05B37/02 ; H05B33/08

Abstract:
A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED; a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.
Public/Granted literature
- US20110115401A1 METHOD AND APPARATUS FOR CONTROLLING BRIGHTNESS OF LIGHT EMITTING DIODES Public/Granted day:2011-05-19
Information query