基于单片机的金卤灯电子镇流器研制

设计了一种基于单片机控制的数控金卤灯电子镇流器.由于数字电路的可控性较强,降低了电路的复杂度,提高了系统的稳定性和可靠性,并有利于提高灯的寿命.经测试表明,该电子镇流器性能稳定,效率较高,满足了设计要求.     

Arc Dynamic Stabilization in Low-Frequency Square-Wave Electronic Ballast for Metal Halide Lamps

Discharge lamps present a negative dynamic characteristic that makes necessary to use a current limiting element. In high-frequency resonant ballasts, current limitation is performed by the output resonant tank; but in low-frequency square-wave electronic ballasts, arc stabilization is accomplished by the stage feeding the square wave inverter. Therefore, the design of the input converter must be made taking into account the lamp dynamic characteristic. In the present paper, a new procedure to obtain the small-signal dynamic characteristic of metal halide lamps is proposed. Using the proposed methodology, the small-signal characteristic of a 70-W lamp is obtained. This characteristic is then used for the design of an electronic ballast based on a buck-boost converter followed by a full bridge inverter. The limits for stable operation obtained are verified using a laboratory prototype.     

一种直流供电的陶瓷金卤灯电子镇流器

设计了一款低压直流供电的陶瓷金卤灯电子镇流器.前级采用具有RCD吸收电路的反激变换器.提高镇流器的效率.后级采用低频方波全桥逆变电路.有效克服陶瓷金卤灯的声共振现象.利用单片机实现陶瓷金卤灯的平滑启动、精密恒功率控制、重启动以及各种异常状态保护.测试表明,该电子镇流器性能稳定,效率较高.     

A Single-Stage High-Power-Factor Electronic Ballast Based on Integrated Buck Flyback Converter to Supply Metal Halide Lamps

In this paper, a novel single-stage electronic ballast with a high power factor is presented. The ballast circuit is based on the integration of a buck converter to provide the power factor correction, and a flyback converter to control the lamp power and to supply the lamp with a low-frequency square-waveform current. Both converters work in discontinuous conduction mode, which simplifies the control. In spite of being an integrated topology, the circuit does not present additional stress of voltage or current in the main switch, which handles only the flyback or buck current, depending on the operation mode. To supply the lamp with a low-frequency square-wave current to avoid acoustic resonances, the flyback has two secondary windings that operate complementarily at a low frequency. The design procedure of the converters is also detailed. Experimental results from a 35-W metal halide lamp are presented, where the proposed ballast reached a power factor of 0.95, a total harmonic distortion of 30% (complying with IEC 61000-3-2), and an efficiency of 90%.     

Study of Igniter in Low-Frequency Square Wave Electronic Ballasts for Metal Halide Lamps

Metal halide lamps (MHLs) have serious acoustic resonance problem. The most widely used method to achieve acoustic-resonance free is to use low-frequency square wave (LFSW) electronic ballasts. There are two ignition methods commonly used in LFSW electronic ballast: high-frequency resonance ignition and additional pulse igniter. This paper analyzed the problems during ignition while using the conventional additional pulse igniter and proposed some solutions. A novel high-frequency resonance igniter is also proposed, where no extra semiconductors and feedback control circuit are needed to perform the ignition. High-voltage ignition pulses are obtained by utilizing the fast polarity inversion of the output voltage of full-bridge inverter. Theoretical analysis, simulation, and experiment results of a prototype for 70-W MHLs verified the effectiveness of both the proposed solutions and the igniter.     

2.65-MHz Self-Oscillating Complementary Electronic Ballast With Constant-Lamp-Current Control for a Metal Halide Lamp

This paper presents the design and implementation of the 2.65-MHz self-oscillating complementary electronic ballast with a constant-lamp-current control for a metal halide lamp. In order to avoid the inherent acoustic-resonance problem of metal halide lamps, the ballast's switching-frequency level was selected to be 2.65 MHz, which satisfies higher magnitudes of maximum electromagnetic interference (EMI) limitation at frequencies of between 2.5 to 3.0 MHz, within the EMI/electromagnetic compatibility frequency range ldquochimney,rdquo for RF lighting systems. With the constant-lamp-current control scheme, the lamp current can be regulated to be less dependent on the input ac voltage. Finally, a 20-W prototype ballast is implemented to demonstrate the ability to avoid the acoustic-resonance and to provide constant levels of lamp current.     

金属卤化物灯制造技术的新技术

金属卤灯是新一代的电光源，它具有高光效，高显色性和长奉命等特性，本文主要介绍了金属卤化物灯目前的最新研究成果及未来的发展动态。     

金属卤化物灯的近期发展和在产业中的应用

金属卤化物灯具有光效高，显色性好的光电特性，能满足产业应用中的各种特殊要求。本文简要介绍了金属卤化物灯的种类，特性和近期的发展，以及在印刷，制板，光学仪器，汽车照明，水产，植物培育等产业方面的应用。     

金属卤化物灯的高频点灯和放电稳定化

为了提高金属卤化物灯的光效，将该灯用电子镇流器在高频下燃点，观察到灯的不稳定性，称为音响共鸣现象。为了克服音响共鸣现象，介绍了四种稳定工作的方法：①在超音响共鸣的频率下工作；②在矩形波下工作；③采用适当的调制频率下工作；④采用三次谐波叠加高频正弦波点灯。本文介绍金属卤化物灯用电子镇流器、高频点灯和放电稳定化。     

High Power Factor Self-Oscillating Electronic Ballast to Supply Four Fluorescent Lamps

This paper presents an innovative modification in the conventional self-oscillating driver, in order to supply variable loads. This modification consists of adding an auxiliary output filter supplying a small power resistor, which also includes the primary winding of the self-oscillating transformer. The analysis for self-sustained oscillations is performed by extended Nyquist criterion, which defines the design equations for the ballast component values. A design example is presented, using the proposed circuit in a high power factor electronic ballast supplying four independent lamps. A passive circuit named valley charge pump is used to perform the power factor correction. The ballast supplies four lamps independently, without considerable frequency changes, with an efficiency of 93%, and reaching IEC 61000-3-2 requirements for the input current distortion.     

环保型新光源--无汞金属卤化物灯

近年来从环境保护和节约能源的观点出发,开发了新型无汞金属卤化物灯,该灯包括充氙气的金属卤化物灯和电感耦合型无电极金属卤化物灯.本文主要介绍该类灯的结构、特性、测量方法和技术的进展.     

Design and Implementation of a Single-Stage High-Frequency HID Lamp Electronic Ballast

We present a single-stage electronic ballast with a high power factor feature for driving high-intensity discharge (HID) lamps. A new frequency-modulation technique is proposed to eliminate the acoustic resonance problem in HID lamps under high-frequency operation. The proposed method has the merits of simple circuit and low cost; thus, it is suitable for use in commercial applications. The conducted emission caused by the high-frequency electronic ballast can be also effectively reduced. The operating principles and design considerations of the proposed electronic ballast are analyzed and discussed in detail. A 35-W laboratory prototype is designed and implemented. Simulation and experimental waveforms are given to verify the feasibility of the proposed method. The results are satisfactory.     

A Novel Discrete Dimming Ballast for Linear Fluorescent Lamps

A novel discrete dimming ballast for linear fluorescent lamps is proposed in this paper. A proposed dimming control circuit is combined with a ballast module for multiple lamps to realize control of three discrete lighting levels. Compared with conventional step dimming or on– off control methods, the proposed discrete dimming method has the following advantages: 1) digital signal is generated by the dimming control circuit to control the lamps' turn- on and -off, which makes the system more reliable and integrated; 2) the proposed discrete dimming system replaces relays, which are necessary in conventional lamp on–off control, and therefore decreases the system cost; 3) the proposed dimming ballast can be installed by keeping the original wiring system. This makes the upgrading of a lighting system more effective and efficient; 4) the dimming control circuit also provides a good isolation for operating the low-voltage wall switches by hand safely. Both theoretical, simulation, and experimental results are in good agreement.      

用于荧光灯的一种单片电子镇流器

VK06TL集成电路有很多功能。这些功能通常需要用大量组件来实现。例如预热电路、荧光灯管使用到最后阶段的保护电路、热保护、双向击穿二极管功能。由于器件本身的运作模式,在荧光灯管使用到最后阶段时能够限制流过电路的大电流,该功能通过在外面增加一个简单便宜的电阻器-二极管电路实现。该器件的工作频率可以用外面的两只电容器来设定。器件中的保护电路提高了器件本身的可靠性以及整个系统的可靠性。     

The Influence of the Startup Process of Small Metal-Halide (MH) Lamps on Electronic Ballast Design

In this paper, the authors present the results of an investigation into the starting process of a small wattage metal halide lamp and address the influence of the starting process, at extra- high frequency (>350 kHz), upon the performance of two most commonly used electronic ballast circuit topologies, namely the LCC resonant inverter and LCL resonant inverter. The starting transient processes driven by both ballast systems are captured, analyzed and explained. It has been found that the starting process could affect the operating performance of an LCL ballast and may destroy its power switches in the worst case while a LCC ballast gets the advantage over the LCL ballast for the stability during the transient starting process.     

Metal Halide Perovskites for Laser Applications

Metal halide perovskites have drawn tremendous attention in optoelectronic applications owing to the rapid development in photovoltaic and light-emitting diode devices. More recently, these materials are demonstrated as excellent gain media for laser applications due to their large absorption coefficient, low defect density, high charge carrier mobility, long carrier diffusion length, high photoluminescence quantum yield, and low Auger recombination rate. Despite the great progress in laser applications, the development of perovskite lasers is still in its infancy and the realization of electrically pumped lasers has not yet been demonstrated. To accelerate the development of perovskite-based lasers, it is important to understand the fundamental photophysical characteristics of perovskite gain materials. Here, the structure and gain behavior in various perovskite materials are discussed. Then, the effects of charge carrier dynamics and electron–phonon interaction on population inversion in different types of perovskite materials are analyzed. Further, recent advances in perovskite-based lasers are also highlighted. Finally, a perspective on perovskite material design is presented and the remaining challenges of perovskite lasers are discussed.     

高性能HID电子镇流器

介绍了荧光灯、高压钠灯以及金属卤化物灯等气体放电灯和其对电子镇流器的基本要求。     

一种用于投影光源的高性能电子镇流器

提出了一种用于投影光源的高性能电子镇流器.主电路采用无源无损的缓冲电路,减小了由于续流二极管反向恢复所引起的开通损耗,提高了镇流器的效率.以数字控制器为核心,结合模拟方式的PWM控制,实现了恒功率控制.分析了镇流器的工作原理并给出了实验结果,实验结果表明该镇流器具有电路简单、可靠性高的优点,实验样机的效率达到了94%.     

Strategic Doping in Metal Halide Perovskites for Thermoelectrics

Metal halide perovskites (MHPs) have not only shown unique merits of ultralow thermal conductivity compared to traditional inorganic thermoelectric (TE) materials, but also featured superior Seebeck effect to organic semiconductors, thereby affording great prospect in TE field. However, their severely poor electrical conductivity significantly hinders TE applications, which results from the restrained doping efficiency due to the limited accommodation capability of heterogeneous dopants and the heavy compensation from interior defects in MHPs. Realizing high-effectiveness electrical doping in MHPs becomes imperative yet remains extremely challenging. This Minireview is therefore intended to sort out the diversified doping strategies and highlight their underlying impacts on both thermal and electrical transportation in MHPs. These strategies are systematically classified into bulk and surface/interface doping as dictated by where the dopants are implemented while unravelling how they critically impact TE properties in distinctive means. A rational guideline is hence derived to strengthen electrical doping towards desirable perovskite TEs.     

显示屏用冷阴极荧光灯镇流器驱动器UBA2070及其应用

UBA2070是驱动电子镇流器的主电压值高达277V（RMS）的冷阴极荧光灯高压IC。本介绍该驱动器IC的特点，工作原理及应用电路。