LCD背光照明四灯管CCFL电子变压器

CCFL被广泛用作大尺寸LCD的背光源。文中重点介绍了基于控制器FAN7548的四灯管CCFL电子变压器电路功能、特点及工作原理。     

倾角变化的窄缝通道内CHF理论模型

对倾角变化的矩形窄缝通道的临界热流密度(CHF)进行分析,基于逆向对流限制(CCFL)机理建立相应的理论分析模型,并将该理论模型的预测结果与已有的实验结果进行对比。结果表明:当矩形窄缝通道尺寸为1 mm和2 mm,且倾角在范围在15°~90°时,预测结果与实验值符合得比较好;在倾角小于15°时,理论模型对CHF的预测明显小于实验值;修正的Katto-Kosho关系式可以比较准确地预测倾角小于15°时的CHF值;当通道尺寸为5 mm和10 mm时,预测值比实验值大,这表明基于CCFL机理的CHF预测理论模型仅适用于通道尺寸小于等于2 mm的窄缝通道。     

Design considerations for a CCFL and its surroundings

Abstract— A TFT-LCD module includes a backlight unit, which normally uses one or more thin cold-cathode fluorescent lamps (CCFLs). Since a CCFL is driven at high frequency and high voltage, there is a leakage current. In recent years, TFT-LCD modules have been getting thinner, with a wider screen size and a narrower frame; consequently, the leakage current has come to have a significant influence on the design of the LCD module and the dc/ac inverter unit that generates the high-voltage ac to drive the CCFL. It is actually impossible to probe the inside of a working CCFL because of the high voltage, high frequency, and low electric discharge current. This fact adds to the difficulty of the analysis and the design. This paper proposes an electrical model of a CCFL and a simulation method using the model, making it possible to analyze the inside of the CCFL and to provide some important parameters that are required for the basic design of the LCD module and the dc/ac inverter, before the construction and measurement of actual samples.     

驱动两灯公共回路的CCFL控制器

本文介绍如何用一个CCFL控制器（DS3882）驱动两个公共回路的CCFL灯管。     

冷段大破口失水事故长期冷却及硼浓度特性研究

文章采用先进的热工水力分析程序CATHAR,对百万千瓦级ACP1000核电厂冷段大破口失水事故冷热段同时安注时CCFL作用下的上腔室及堆芯的流动换热特性、硼浓度特性进行了研究,并分析了破损环路热段安注流量大小对堆芯冷却的影响。研究表明：在热段安注总流量为614 m3/h时,破损环路对应热段安注流量的不同,不会对流入堆芯冷却有较大影响,破损环路热段安注流量差异不会对堆芯冷却有较大影响;切换至同时安注后堆芯硼浓度很快与系统达到平衡。     

Analysis of LSC phenomena of ATLAS cold leg SBLOCA tests using MARS-KS code

Loop seal clearing (LSC) is an important phenomenon for the safety of a pressurized water reactor (PWR) during a small-break loss-of-coolant accident (SBLOCA). The investigation on an LSC phenomenon of 4″, 6″, and 8.5″ break cold leg SBLOCAs simulated by Advanced thermal–hydraulic Test Loop for Accident Simulation (ATLAS) is performed using a Multi-dimensional Analysis of Reactor Safety-KINS Standard (MARS-KS) code. The LSC triggers earlier for larger break sizes during tests and calculations. LSCs occur during the simultaneous sudden decrease of steam condensation rate and the sudden increase of the break volumetric flow rate while the core volumetric flow rate increases slowly in calculation. The five phases of an SBLOCA transient are blowdown, pressure plateau, LSC, boil-off, and core-recovery phase, which can be identified by observing the volumetric flow rate and the time-dependent pressure variation. Loop seal refilling (LSR) occurs due to the trivial steam flow rate to the crossover leg inlet in calculation. The sensitivity analysis shows that the combination of countercurrent flow limitation (CCFL) model option for hot leg and steam generator (SG) inlet (Kutateladze, c = 1.36, m = 1), crossover legs (Kutateladze, c = 1, m = 1), and SG U-tubes (Wallis, c = 1, m = 1) provide good prediction of the LSC phenomenon and thermal-hydraulics behaviors in an SBLOCA transient by MARS-KS code calculation.     

大尺寸LCD-TV用冷阴极管的最新技术动向

背光源的成本和性能指标的优劣是决定大尺寸液晶电视竞争力的关键因素,本文对目前大尺寸液晶电视用冷阴极管背光源技术的最新动向作简要介绍,并将之与其它新型背光源技术如平面光源以及发光二极管背光源技术相比较,从而得出目前以冷阴极管作为大尺寸液晶电视背光源仍为主要趋势的结论.     

DS3991在液晶背光中的应用

DS3991芯片是美信公司最新推出的一种智能、高效的冷阴极荧光灯(CCFL)控制器,具有优良的动态性能和完善的保护功能,利用它可以与功率MOSFET、变压器构成一组低成本的CCFL控制系统。本文介绍了DS3991芯片的特性与原理,分析了关键电路的设计方法及器件选型,并给出了其两种应用电路。     

液晶背光用冷阴极荧光灯劣化老化原因及对策研究

冷阴极荧光灯（CCFL）是液晶背光模组的主要部件之一,它的优劣会直接影响背光模组的光学性能。文章较为全面地分析了冷阴极荧光灯亮度衰减的常见原因,并对延长冷阴极荧光灯使用寿命的方法做了深入的研究和总结。     

用于液晶显示器件的侧光式CCFL背光源研究

文章阐述了背光源的基本原理和主要分类,对侧光式CCFL背光源做了深层次的研究,并对其各主要部件的材料、工作原理、光学特性、在背光源中的主要作用都做了详细的阐述。