Research of the Current Balanced Techniques for Multi-CCFLs Driven by Single Transformer
| Autor: | Jhao-Wei Liou, 劉兆偉 |
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| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Recently, the liquid crystal displays were developed rapidly and successfully in recent year, the relative backlight modules were paid attention and become an important key-part also. In the market competition, how to attain high performances in the lowest cost and let the current distribution among the cold cathode fluorescent lamps (CCFL) to be balanced in order to extent the life-span of the display are the common subject to all manufacturers. An integrated circuit, TL-494, was adopted to design the drive circuit, and the zero voltage switching (ZVS) was reached by connecting push-pull output to the full-bridge module. Meanwhile, instead of the conventional individual driving circuit design technology, the multi-CCFLs are driven by a single transformer. The secondary windings were connected in series through the individual lamps which be connected a balance coil separately to complete the current balanced configuration. The methodology and circuit configurations were implemented and tested according to the specifications and requirements of the commercial market considerations. The results shows that the unbalanced current distribution among the lamps had been improved evidently for various different stray capacitances of lamps, the overall performances are much better than the structure of single CCFL driven by single transformer. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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