• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.296-299
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• 1987

The purpose of this paper is to increase the lamp efficacy by filling the optimal Nitrogen gas pressure in the outer enclosure of metal halide lamp. This study presents a new model of Langmuir in the outer enclosure of discharge lamp. In this paper, in the first place, the diameter of Langmuir sheath and the total gab loss were calculated. Secondly, the each gas loss was computed if the arbitrary gas pressure is filled, With the calculated data, flash over which affects the lamp efficacy, lamp life and color rendering was considered. In case of the established discharge lamp, the gab pressure has been filled by experience only roughly. The gas loss is converted into the radiation output. Therefore, the lamp efficacy is improved by reducing the gas loss.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.68-74
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• 2007

For carnation productivity improvement, compact-low cost discharge lamp type ozonizer using pulse power source is designed and manufactured. This paper describes the discharge characteristics and the ozone generation characteristics with variation of the output voltage of pulse power source, the quantity of flowing air and the operating number of ozonizer. The important conclusions are as follows. The discharge voltage and current values are proportional to the output voltage of pulse power source. The ozone concentration and generation are proportional to the output voltage of pulse power source and the number of ozonizer. The maximum value of the ozone concentration and generation of the discharge lamp type ozonizer can be obtained 890[ppm] and 59.7[mg/h] respectively. In the carnation productivity house, when the discharge lamp type ozonizer is used the carnation is good quality in the uniformity of the carnation stalk thickness and increased the productivity through improvement of the air and the soil.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.400-407
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• 2013

This study was performed to analyze the effect of light quality of discharge lamp on growth and phytochemicals contents of lettuce (Lactuca sativa L. cv. Jeokchima) grown under metal halide (MH) lamp, high-pressure sodium (HPS) lamp, and xenon (XE) lamp in a plant factory. Cool-white fluorescent (FL) lamp was used as the control. Photoperiod, air temperature, relative humidity, $CO_2$ concentration, and photosynthetic photon flux (PPF) in a plant factory were 16/8 h (day/night), $22/18^{\circ}C$, 70%, 400 ${\mu}mol{\cdot}mol^{-1}$, and 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. MH lamp had the greatest fraction of blue light (400-500 nm) of 23.0%. However, HPS lamp had the lowest fraction of 4.7% for blue light and the greatest fraction of 38.0% for red light (600-700 nm). At 11 and 21 days after transplanting, leaf length, leaf width, leaf area, shoot fresh weight, and shoot dry weight of lettuce as affected by the light quality of the discharge lamp were significantly different. The leaf area of lettuce grown under HPS, MH, and XE lamp increased by 45.7%, 16.3%, and 9.5%, respectively, as compared to the control. These results were similar for shoot fresh weight. Growth characteristics of lettuce grown under HPS lamp increased since HPS lamp had more fraction of red light. However, growth of lettuce grown under MH and XE lamp decreased since they had more fraction of blue light. As compared to the control, the ascorbic acid in lettuce leaves grown under discharge lamp decreased. The greatest anthocyanins accumulation of 0.70 mg/100 g was found at MH treatment. Anthocyanins content in lettuce leaves grown under XL and HPS lamp were 79.3% and 8.6%, respectively, compared with the control. Growth and phytochemicals contents of lettuce were highly affected by the different spectral distribution of the discharge lamp. These results indicate that the combination of discharge lamp or LED lamp for enhancing the light quality of discharge lamps is required to increase the growth and phytochemicals accumulation of lettuce in controlled environment such as plant factory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.3795-3801
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• 2011

The mathematical simulation of voltage and current waveform of the discharge lamp is useful for the analysis and design of ballasting circuits. This paper proposes a mathematical model which has lamp power and negative voltage drop in discharge lamp. Simulation applying the proposed model has been done, and the results are compared with the experimental results. Furthermore, in the paper, the ballast components(core, transformer) was designed such that high intensity discharge could be optimized for the automotive, by applying a method simulation based design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.465-466
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• 2007

In electrode-less lamp, The key point in creating an efficient light source based on RF discharge is to minimize the RF power loss in the RF coupler which for Anderson's type of RF lamp is due to losses in the ferrite core. This loss depends on the particular ferrite material, its size, geometry, frequency in this kind of inductive lamp shows that the correct choice of discharge current has a crucial effect on the core loss. In this study, we measured Ferrite temperature in normal state, then analyzed electrical and optical characteristics according to ferrite shape. We were able to know that was ferrite of the antenna had relate closely with temperature and luminous of the lamp. Also we appraised temperature and electrical, optical properties during turn on the lamp.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.725-729
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• 2003

In this paper, a mercury-free flat discharge lamp with opposite electrode structure, a couple of phosphor layer and discharge vessel has been studied for LCD back-lighting. When the drive voltage conditions were set properly, a uniform discharge generates over entires emitting surface. The firing voltage was increased with increasing the discharge gas pressure. It was considered that this tendency was resulted from the decrease of mean free paths due to the increase of discharge gas pressure. The maximum luminance of 2700[cd/m2] was obtained in the green emitting FFL.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1786-1788
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• 1999

In this paper, we studied Surface Discharge Type Flat Fluorescent Lamp with High Luminance for LCD Backlighting, Liquid Crystal display(LCDs) demand the use of fluorescent lamp as the backlighting source. This lamp is Surface Discharge Type structure with a pair of Sodalime glass, insulator layer, phosphor layer, and Xe gas gap. In spite of its simple structure, the lamp has uniform and stable discharge over entire volume. Till now, we measured the current-voltage(V-I), Firing Voltage, Sustain Voltage for 0.5mm, 1mm electrode gap. In experiment result, long gap cell structure cause high firing voltage. The rising in firing voltage in long gap structure could not be explained by paschen's law because of non-uniform electric field.

• Journal of Power Electronics
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• v.10 no.6
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• pp.777-783
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• 2010

In order to drive gas discharge lamps, DC-AC converters with a LCC resonant tank, whose output voltage is adjusted by a variable frequency control are frequently used. However, when they are activated by varying the operating frequency, converters are frequently damaged by unstable operation, due to the rising and falling of the operating frequency near the resonant frequency. To solve this problem, a simple protection circuit for the power supply of a gas discharge lamp is proposed in this paper. This circuit senses the primary current of the main transformer. Using this protection circuit, the operating frequency of the lamp driving inverter system is kept close to and on the right side of the resonant frequency and the inverter is always operated in the ZVS condition. The resulting stable variable frequency operation allows various gas discharge lamps to be tested without the risk of damaging the main switches, because the protection circuit can protect the power MOSFETs of bridge converters from abnormal conditions. The validity and effectiveness of the proposed protection circuit are verified through the experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.25-34
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• 2001

In this paper, discharge lamp ozonizer(DLO) of a new discharge type using superposition of gaseous electrical discharge for environment improvement was designed and manufactured. DLO is equipped with 3 electrodes(central ground electrode of discharge lamp type internal high voltage electrode of mesh type and external high voltage electrode of spiral type), and it is composed of double gap(gap between discharge lamp and internal electrode, gap between discharge lamp and external electrode). Internal and external electrodes are respectively applied AC high voltage which has 180[$^{\circ}$] phase difference. Ozone is generated by overlaying of each silent discharge which is respectively came from two gaps. At the moment discharge characteristics and ozone generation characteristics of DLO were investigated in accordance with quantity of supplied gas, discharge power and the number of DLO. When ozone generated by DLO was in contact with NO gas, removal characteristics was excellent, so it confirmed that DLO could be used as air environment improvement facility.

• Korean Journal of Materials Research
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• v.13 no.4
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• pp.271-278
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• 2003

Conventional backlight for liquid crystal display (LCD) uses mercury which leads to environmental pollution. In this study, characteristics of AC coplanar type mercury-free plasma flat lamp have been studied. Pollution-free Xe-He is adopted as a discharge gas system. Since the Xe gas has a lower efficiency in generating vacuum ultraviolet (VUV) than mercury, the improvement of luminance and luminous efficiency in the Xe gas system is very important. The electrode, dielectric, and phosphor layers constituting lamp are formed on the bottom glass by the screen printing method. The effects of pulse shape, on-time, and pulse frequency on the luminance and luminous efficiency have been examined. For Xe(5%)-He gas, the lamp exhibits higher efficiency with sharper pulse shape, higher peak voltage, and shorter pulse on-time (up to 2 $\mu\textrm{s}$). Higher efficiency and lower consumption of power were obtained at 30 kHz than at 60 kHz. The collision of ion to bottom electrodes is a dominant factor to raise the lamp temperature. Therefore the high voltage and low current discharge system is necessary for reduction of the lamp temperature as well as for enhancement of the luminous efficiency.