• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.3-6
• /
• 2008

The purpose of this study is to investigate the luminous environment of fluorescent lamp and LED lamp in a office space for various color temperature by subject response test. For this, three different color temperatures were tested for the same illuminance level. Based on such test results for various color temperatures of fluorescent lamp and white LEDs, this study is to analyze the preferences of color temperature and light source, and perceptional brightness of each light source and color temperature. Then, this study is to derive the guidelines for the performance of color temperature which are suitable on the purpose and the mood of a office space.

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.766-768
• /
• 1988

Electron mobility which is a basic parameter to represent gas state, is calcurated using equation assumed Lorentz gas. This equation is applied to 30mm 20W fluorescent lamp. In order to obtain electric field strength of positive column, lamp and cathode fall voltage wave form is measuread using indirect voltage measuring methode. To obtain electron density, used the calculation of S.C Peek and D.E Spencer. The result which is applaied 38mm fluorescent lamp at 400mA, $20^{\circ}C$ is displayed.

• Journal of the Optical Society of Korea
• /
• v.12 no.3
• /
• pp.174-177
• /
• 2008

The luminance properties of FFL(Flat Fluorescent Lamp) backlights have been investigated in detail for the first time. The on-axis luminance gain as well as viewing-angle characteristics on various combinations of optical films were obtained from FFL backlight and compared to the results of conventional CCFL(cold-cathode fluorescent lamps) backlights. It was found that the on-axis luminance gains achieved by using optical films in the FFL backlight were lower than those in the CCFL backlight indicating that the recycling processes occurring between optical films and light sources/reflection sheet are not so effective in the FFL backlight due to the much larger area of, and thus higher absorption probability of the FFL. This result suggests that new optical films should be developed for FFL backlight and other flat-lamp backlight technologies.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1995.10a
• /
• pp.47-52
• /
• 1995

This paper presents a new approach in the design of an electronic ballast for fluorescent lamps in the range of 10∼20W. The central point of the design lies in the equivalent concepts for a lamp and for the inverter part of an electronic ballast. The ballast, which adopts half-bridge inverter topology, is designed to adjust ifself to a predefined range of lamp power output by frequency control using MCU. At first, the circuit parameters were estimated using PSpice simulatio, and then were made varied according to the selection of an optimal frequency for each lamp. A series of experiments using fluorescent lamps of 11W, 15W, and 20W were carried out to verify the proposed design. As a result of the experiments, all the three lamps of different kind were run normally with the same ballast under consideration, And the characteristics on lamp starting and light output were satisfactory compared to existen single-output electronic ballasts.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1425-1427
• /
• 2009

In this paper, we investigated influence of gas pressure and gas mixing ratio on the abnormal discharge characteristics of fluorescent lamp. Abnormal discharge characteristics have been examined by changing inner gas pressure and mixing ratio. As the inner gas pressure and mixing ratio increase, the occurrence of abnormal discharge was delayed. It was found out that the occurrence of abnormal discharge is sufficiently delayed at the optimized inner gas pressure and mixing ratio.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1199-1201
• /
• 2000

This paper proposes a harmonics reducing circuit for fluorescent lamp inverters using hybrid type smoothing circuit with pumping and smoothing capacitors. A waveform of full-wave rectification used as a direct current power supply at fluorescent lamp inverters contains a lot of harmonic wave from inrush current which is generated near the maximum of input voltage with purse shape when voltage smoothing capacitor is charged. Therefore, in order to suppress inrush current which will result in harmonic wave. this paper proposes a method to control abrupt charging current by use of charging voltage at pumping capacitor. The suppression of harmonics generation at lamp current is confirmed through simulations.

• Journal of Power Electronics
• /
• v.15 no.2
• /
• pp.567-575
• /
• 2015

An improvement in the current fed parallel resonant half bridge (CFPRHB) circuits used in fluorescent lamp electronic ballasts is provided in this paper. The CFPRHB belongs to the self-oscillating family which includes the current fed push-pull and series resonant inverters, most of which are used in instant-start applications. However, many failure modes are related to the bypass capacitor according to an analysis of failed samples. In this paper, the operating functions of the existing topology in the steady state are analyzed and the main root cause of failure modes has been found. Comparisons between the two topologies are conducted in terms of the voltage stress of the bypass capacitor as well as the thermal and performance of the ballasts to verify the advantages of the proposed topology. It is found that the improved topology is capable of enhancing the reliability and reducing the cost of products without having a negative influence on the system performance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.12
• /
• pp.1105-1110
• /
• 2008

In this study, plasma flat fluorescent lamps (FFLs) having two electrode type structures of surface discharge was fabricated by screen printing and were characterized using spectra-radiometer and square pulse power supply. Two types of FFLs (cross-type and line-type electrode structure) were compared with variation of discharge shape and electrode distance.

• Proceedings of the KIEE Conference
• /
• 2003.10a
• /
• pp.249-251
• /
• 2003

The ring-shaped electrodeless lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the line time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250[kHz] and some specific conditions.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.149-149
• /
• 1999

This paper is to present a selected method of circuit parameters in the inverter part of the electronic dimming ballast for fluorescent lamps, that is adequate to use with the prevailing dimming controller IC. Through the experiment result using the prototype of the electronic dimming ballast produced by this method, its validity is verified from the electrical and light output characteristics on fluorescent lamps. Also, it is feasible to remote automatic and passive control fur dimming electronic ballast as using a microprocessor, and we easily recognize the lamp condition owing to make a program indicate abnormal behavior for fluorescent lamp at PC screen.