• The Transactions of The Korean Institute of Electrical Engineers
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• 제56권12호
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• pp.2157-2165
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• 2007

A novel design technology for a high frequency electronic ballast for metal-halide discharge lamps is proposed. A PFC technique is adopted to get unit power factor and output frequency alteration technique is adopted to avoid acoustic resonance. For characteristics evaluation, the designed electronic ballast is presented using normalized parameter. To reduce losses of the ballast. ZVS control technique is adopted and the maximum flux density of magnetic core for inductor should be kept lower. The electronic ballast for 250[W] metal-halide discharge lamp is implemented and 96[%] efficiency and low conducted EMI level are accomplished.

• Proceedings of the KIPE Conference
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.241-244
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• 2002

This paper presents the electronic ballast for the metal halide lamp with free voltage input and implemented for CDM-T[150W] lamp. HID lamps have a good color rendition, long life and good focusing capability but they have fickers by acoustic resonance when driven at high frequency. To reduce the acoustic resonance phenomena, the electronic ballast was designed for high frequency operation with the constant frequency sinusoidal wave of 75[kHz]. Finally, the experimental results on the ballast of CDM-T [150W]metal halide lamp with the propose methods are discussed.

• Journal of Industrial Technology
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• 제30권A호
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• pp.75-81
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• 2010

We described the operating principles of two different type of igniters for lightning of Ceramic Metal Halide Lamp(CMHL) and also provide some useful comparisons. One is for magnetic ballast, the other one is for electronic ballast which operates lamp by low-frequency square-waveform. Ignition voltage of lamp depends on the structure of igniter, such as the length and electrical characteristics of cable, which make troubles for ignition in real sites. Therefore, we measured and analyzed ignition voltages from igniters which are used in magnetic and electronic ballast in cables at a distance of 5 meters between a lamp and a igniter to suggests an applicable solution in real sites.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제58권10호
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• pp.1947-1953
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• 2009

Metal halide (MH) lamps have been largely used due to high luminous efficiency, good color rendering, and long life. Since the metal halide lamps have problems of high ignition voltage and acoustic resonance. Thus, the design of ballast is very difficult for engineers. This paper proposes prototype of electric ballast in order to solve above two problems. The proposed electric ballast is consisted of EMI filter, full wave rectifier circuit, active PFC, DBI(Dual Buck Inverter), dimming circuit and ignitor circuit. The DBI supplies both rectangular voltage and current to the lamp. As the result of the experiment, the acoustic resonance was eliminated and the ignitor circuit was designed to generate high ignition voltage than 5kV. It makes the dimming circuit possible to control the lamp power in range between 230W and 350W.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.160-162
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• 2004

The aim of this study is to make the technical standards for certificating a high efficiency metal-halide lamps and reflectors using the high intensity discharge lamps, to accomplish the practical energy saving effect. Metal-halide lamps are certificated by stabilzed and restarting time, lamp voltage, current, power and light output efficiency. The high illumination reflectors using HID lamps are certificated by testing reflective index, fading, the melting point, glare and install spacing factor.

• Proceedings of the KIPE Conference
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.589-593
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• 2001

This paper presents a high frequency modulation electronic ballast for the metal halide lamp. As the proposed ballast operates in high frequency ranges (20kHz - 100kHz) and it can start up the lamp using the LC resonant circuit without external igniter, the proposed ballast is very compact. The proposed ballast is controlled with the modulated frequency in the range of 20kHz to 100kHz, and it has variable modulating frequencies between 200Hz and 2kHz in order to avoid the acoustic resonance phenomenon. In this paper, a new realtime acoustic resonance detection method is described and the experimental results with the proto-type ballast of 150W metal halide lamp with the dimming function are discussed.

• Nuclear Engineering and Technology
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• 제7권1호
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• pp.25-29
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• 1975

Kinetics of halogen exchange reaction of 1-phenthyl chloride and 2-phenethyl chloride using radioisotopic tracer halide ions in acetone have been studied. The reactions were belived to be S$_{N}$2 processes and the orders of relative nucleophilicity of halide ions were Cl->Br->I-. The reaction rate is slower than that of benzyl chloride. These were interpreted in terms of solvation effect of halide ions and HSAB principle.

• Journal of Electrochemical Science and Technology
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• 제13권1호
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• pp.71-77
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• 2022

Metal halide perovskites are promising photovoltaic materials, but they still have some issues that need to be solved. Hysteresis is a phenomenon that strongly is correlated with ion migration; thus, a fast, easy, and low-temperature method for measuring ion migration is required. Through selective blocking, ion migration can be measured separately, apart from electron migration. In this study, ion migration in metal halide perovskites was measured using a vertical device. At different temperatures, ionic activation energies were obtained for a range of perovskite compositions such as MAPbI₃, FAPbI₃, CsPbI₃, and MAPbBr₃. By comparing the measured ionic activation energies with the theoretical values, we conclude that among other possibilities, I^- is the migrating ion in MAPbI₃, FAPbI₃, CsPbI₃, and Br- is the migrating in MAPbBr₃.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제37권5호
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• pp.519-526
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• 2024

This review examines the use of halide perovskite materials in electronic devices, highlighting their exceptional optoelectronic properties and the challenges associated with them. Despite their potential for high-performance devices, practical applications are limited by sensitivity to environmental factors such as moisture and oxygen, etc. We discuss advances in enhancing stability and operational reliability, featuring innovative synthesis methods and device engineering strategies that help mitigate degradation. Furthermore, we explore the integration of perovskites in applications such as field-effect transistors and LEDs, emphasizing their transformative potential. This review also outlines future research directions, stressing the need for ongoing improvements in material stability and device integration to fully realize the commercial potential of perovskites.

• Journal of the Korean Society of Marine Environment & Safety
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• 제19권6호
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• pp.681-687
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• 2013

This study analyzed characteristics of 240 W high power LED lamps by comparing with those of traditional metal halide lamps. In addition, it analyzed the propriety of LED lamps as a source of light, considering seawater transmission characteristics. When Applying white LED package with the color temperature color temperature of 6500K, a 240W-LED fishing lamp has a characteristics of the luminous angle to be expanded to ${\pm}45^{\circ}$, the illumination change was improved to 0.8, as well as the luminance efficiency was improved to 98.8lm/W. As results of comparison between one 1,500W-metal halide lamp and four 240W-LED lamp with considering a seawater transmission and a luminous efficiency of scotopic vision, the radiant flux of two lamps were almost equal level at 50m depth and the luminous flux was 5% higher LED lamp than metal-halide lamp even if only applying the luminous efficiency of scotopic vision. As the luminous flux of LED lmap was 14% higher than that of metal-halide lamp with applying the luminous efficiency of scotopic vision to radiant flux at 50m depth, so LED fishing lamp was verified to alternative possibility of metal-halide lamp.