• Title/Summary/Keyword: Lamp current

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Comparative Analysis on Characteristics of the Circular type Electrodeless Fluorescent Lamp System (둥근형 무전극 형광등 시스템의 특성 비교 분석)

  • Cho, Mee-Ryoung;Shin, Sang-Wuk;Lee, Se-Hyun;Hwang, Myung-Keun;Kim, Young-Wook;Ham, Jung-Koel
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.69-72
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    • 2004
  • In this paper, we measured the electrical and optical characteristics of an electrodeless fluorescent lamp system as product of the inside and outside of the country and compared the measured data. Output current wave of domestic 150 W is unstable than it's of Endura 150 W. But the former of spend time after discharging and output current value is small than the latter. And optical characteristics(brightness, flux, color rendering index, efficiency) value of the former is a little small than the latter. In conclusion, if we improve a little more quality then we must secure the superiority in competition.

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Fabrication of a Large LCD Backlight Unit with Red, Green, and Blue LED Lamps

  • Kim, Hee-Tae;Noh, Seung-Jeong;Choi, Yong-Seok;Yu, Soon-Jae
    • Journal of Information Display
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    • v.10 no.3
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    • pp.97-100
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    • 2009
  • A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

Navigation control for a mobile robot using a camera (카메라를 이용한 이동 로보트 주행 제어)

  • 문순환;한민홍
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1994.04a
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    • pp.42-48
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    • 1994
  • This paper presents the navigation method for a mobile robot which uses a single camera and fluorescent lamp as a guide mark, projected on a convex mirror. The current position and heading direction of the mobile robot are obtained from the image of the guide mark. While the mobile robot travels to a goal position, the current position and heading direction of the mobile robot are updated continuously and the desired path and actual moving path are displayed on the monitor screen in real time. This proposed method eliminates the need to rotate the camera to track the guide mark, since a panoramic view of the surrounding area is available from the convex mirror, and natural guide marks such as usual florescent lamp on the ceiling or door frame can be used for navigation.

Photo and Electrocatalytic Treatment of Textile Wastewater and Its Comparison

  • Singaravadivel, C.;Vanitha, M.;Balasubramanian, N.
    • Journal of Electrochemical Science and Technology
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    • v.3 no.1
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    • pp.44-49
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    • 2012
  • Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.

A Theoretical Analysis of Voltage and Current in Low Pressure Mercury-Argon Mixture Gas Discharge with Frequency Variation (저압 수은-아르곤 혼합기체 방전의 주파수에 따른 전압, 전류 변화의 이론적 해석)

  • Yi, Chin-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.2
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    • pp.23-27
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    • 2005
  • A fluorescent lamp which uses low pressure mercury-argon gas discharge shows the maximum current and minimum lamp voltage near 1(kHz) source frequency at constant power. For explain these phenomena theoretically, in this paper a atomic level discharge model was made and particle density and electron temperature variation were calculated using numerical method.

The design of CCFL Driving Circuit by Resonant Invertor and Dimming IC (조도조절이 가능한 공진형 인버터 적용 CCFL 구동회로의 설계)

  • Kim, Cherl-Jin;Ji, Jae-Geun;Kim, Sung-Lae;Yoon, Shin-Yong
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1181-1183
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    • 2003
  • Cold cathode fluorescent lamp(CCFL) are widely used to illuminate the liquid crystal display(LCD). Usually, CCFL dimming methods are used to lamp current regulation or average current adjust feeding the CCFL inverter. Switching frequency of inverter is higher than resonant frequency at stabile states. In this study, design of CCFL driving circuit by half-bridge type series and parallel resonant inverter that variable frequency modulation method to control the output power. This method has advantages such as low EMI and reduced harmonics. And it is easy to dimming control use microprocessor. The validity of this study is confirmed from the simulation and experimental results.

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Comparative Analysis on Characteristics of the Circular type Electrodeless Fluorescent Lamp System (국내외 전구형 무전극 형광등 시스템의 특성 비교 분석)

  • Cho, Mee-Ryoung;Shin, Sang-Wuk;Lee, Se-Hyun;Hwang, Myung-Keun;Kim, Young-Uk;Ham, Jung-Koel
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.157-160
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    • 2004
  • In this paper, we measured the electrical and optical characteristics of an electrodeless fluorescent lamp system as product from the inside and outside of the country and compared the measured data. Output current wave of domestic 85W is unstable than it's of QL 85 W and the former of spend time after discharging and output current value is larger than the latter. Moreover optical characteristics(brightness, flux, efficiency) value of the former is small than the latter but color rendering index is equivalent. In conclusion, if we improve a little more quality then we must secure the superiority in competition.

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Effectiveness of Photocatalytic Techniques for Disinfection of Indoor Bioaerosols (실내 미생물 입자 살균을 위한 광촉매 기술의 효율)

  • Shin, Seoung-Ho;Kim, Mo-Geun;Jo, Wan-Kuen
    • Journal of Environmental Science International
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    • v.16 no.7
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    • pp.785-791
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    • 2007
  • The current study evaluated the technical feasibility of the application of titanium dioxide ($TiO_{2}$) photo-catalytic air cleaners for the disinfection of bioaerosols present in indoor air. The evaluation included both laboratory and field tests and the tests of hydraulic diameter (HD) and lamp type (LT). Disinfection efficiency of photocatalytic oxidation (PCO) technique was estimated by survival ratio of bacteria or fungi calculated from the number of viable cells which form colonies on the nutrient agar plates. It was suggested that the reactor coating with $TiO_{2}$ did not enhance the adsorption of bioaerosols, and that the UV irradiation has certain extent of disinfection efficiency. The disinfection efficiency increased as HD decreased, most likely due to the decrease in the light intensity since the distance of the catalyst from the light source increased when increasing the HD. It was further suggested that the mass transfer effects were not as important as the light intensity effects on the PCO disinfection efficiency of bioaerosols. Germicidal lamp was superior to the black lamp for the disinfection of airborne bacteria and fungi, which is supported by the finding that the disinfection efficiencies were higher when the germicidal lamp was used compared to the black lamp in the laboratory test. These findings, combined with operational attributes such as a low pressure drop across the reactor and ambient temperature operation, can make the PCO reactor a possible tool in the effort to improve indoor bioaerosol levels.

Analysis on the Light Source Efficiency of CCFL and LED Monitors (CCFL 및 LED 모니터 광원 효율 분석)

  • Shin, Hee-Woo;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.44-50
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    • 2021
  • In this paper, we analyze the efficiency of light sources of CCFL and LED monitors. Cold Cathode Fluorescent Lamp (CCFL), which is widely used as a light source for LCD display, supplies a high voltage of 1,200[V] or more when it is initially driven. In addition, a constant normal voltage of 400 ~ 800[V] after lighting, and 3 ~ 6[ mA] is needed for a power circuit that can stabilize the current. Applying a high voltage causes a lot of stress on the inverter and generates a lot of heat in the cold cathode lamp, causing significant damage to the BLU (Back Light Unit), resulting in a burning phenomenon, which causes the screen to output normal colors when outputting the screen. We can not see the yellow output and the screen darkened. Therefore, in order to prevent such a symptom in advance, efficiency can be increased by using a Light Emitting Diode (LED) as the light source of the LCD display instead of a cold cathode fluorescent lamp (CCFL). As a result, it is shown that the LED method outperforms the CCFL method.

Discharge Characteristics of Surface Discharge Type FFL for LCD Backlighting (LCD 백라이트용 면방전형 FFL의 방전 특성)

  • Lim, M.S.;Yun, S.H.;Shin, Y.S.;Jung, D.Y.;Kwon, S.S.;Lim, K.J.
    • 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.

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