Design and Implementation of a Digital Multi-Channel Dimming System

• Main Authors: Jui-Hung Chen, 陳瑞鴻
• Other Authors: Sheng-Dong Xu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/48496459430089996109

碩士 === 國立臺灣科技大學 === 自動化及控制研究所 === 104 === In this study, we design and implement a class of digital multi-channel dimming systems to achieve the goal of convenienty regulating the change of multi-stage resolution in LED (Light Emitting Diode). The digital multi-channel (Digital Multiplex 512) adopts asynchronous serial communication, in which the baudrate is 250Kbps, and each frame has eight data bits to determine the action. Therefore, it can provide the values from 0 to 255 to describe various different situational control, and each group of light sources has 256 kinds of color strength. In this experiment, three groups of light sources (R, G, B) are planned, and then 256 × 256 × 256 = 16,777,216 kinds of color can be constituted. In this proposed concept, an LED panel is applied to displaying the status of data and signals. The buttons are designed for the menu switch, intensity adjustment, and functional selection. By using the selection menu, one not only can diversely select different R, G, B, light sources, but also can timely adjust duty cycle changing from 1%-100% to change the intensity of light sources. The R, G, B, light source control also can be processed by three groups of knobs simulating A/D conversion. Moreover, two different types of buck DC-DC high-efficiency power driving ICs are adopted to do the constant current output control. In the LED matrix board, we design the series and parallel short-circuit device to prevent three strings of LED from not working due to the damage of any LED. In the future, we can extend relative research based on the gate driving circuit and matrix circuit. Finally, the implementation and verification demonstrate the feasibility of the proposed design concept.