• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.413-415
• /
• 1995

This paper presents a new approach in the design of multiple power output electronic ballasts for compact fluorescent lamps which power output range of 11W, 15W, 20W by using equivalent resistance and RLC equivalent circuit concept and frequency control. A multiple power output electronic ballast which adopts half-bridge inverter topology is set up to compare the results of PSpice simulation with experimental ones. Starting characteristics of lamp voltage, lamp current and light output are better than the existing electronic ballasts, and therefore is verified the validity of the proposed method.

• Journal of the Korean Vacuum Society
• /
• v.12 no.1
• /
• pp.46-50
• /
• 2003

Characteristic properties of backlight arraying external electrode fluorescent lamps has been investigated indriving with a square wave from switch inverters. In the backlight of 17 inch-diagonal with 12 lamps, the efficiency of 65-70 1m/W with the luminance of 5,000-10,000 cd/$\textrm m^2$ has been achieved in the frequency range 40-80 kHz where the higher frequency provides the lower operating voltage in the range 1.0-2.0 kV. In the frequency above 80 kHz, a stable and an uniform luminance in the backlight panel can not be achieved.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.3
• /
• pp.91-96
• /
• 2014

Modern electronic circuits are becoming more vulnerable to damage by surges, and it is required to improve the impulse withstand voltage performance of electrical and electronic equipment. This paper presents the impulse withstand voltage performance of lighting equipment connected to power lines, and the impulse withstand voltage tests for fluorescent lamp, LED lamp and halogen lamp were carried out according to the reference standards under normal service conditions. To conduct performance tests against lightning surge, a combination wave ($1.2/50{\mu}s$ voltage - $8/20{\mu}s$ current) was employed. The test surge was applied between lines or between line and ground of the specimen to be measured. The test surge was applied synchronized at the peak value of the positive and negative AC voltage waves. As a consequence, some specimens satisfied the impulse withstand voltage test criteria, but lighting equipment such as 36W fluorescent lamps, 5W and 5.5W LED lamps and 50W halogen lamp were damaged at the test voltage levels between power lines. It is needed to improve the qualities of lighting equipment to satisfy EMC immunity requirements of equipment for general lighting purposes.

• Journal of Korean Institute of Fire Investigation
• /
• v.11 no.1
• /
• pp.41-58
• /
• 2008

The history of illumination has been much long since the discovery of lamplight caused huge changes in human lives. However, the swift development of the illumination actually started with the invention of a carbon filament lamp by Thomas Edison in 1878. Generally, the illumination tools plays important roles in human lives such as reduction of fatigue, improvement of safety and working efficiency, and the creation of enjoyable atmosphere. But, the illumination tools can be an origin of the fire due to carelessness and lack of management. In this study, the principle and structure of the illumination lamp were dealt with. The possibility of the fire outbreak caused by the incandescent lamp and fluorescent lamp most used in home was investigated. The examples of the fire outbreaks by the incandescent and fluorescent lamps and by the contact between the inflammable materials and the distributing wires were mentioned and demonstrated by the experimental.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.05a
• /
• pp.74-76
• /
• 2006

An external electrode fluorescent lamp (EEFL) has an advantage of a long lifetime in the ear1y stages of the study on plasma discharge, interest in the lamp continues. Researches on the operation of external electrode fluorescent lamps have focused mainly on its use of a type of high frequency (MHz). By performing high brightness using a square wave operation method with the low frequency below 100kHz, which is applied to a narrowed tube type lamp that has several mm of lamp diameter, EEFL presented the possibility of using it as a light source for back-lights. However, because EEFL generates plasma using wall charges, which considers the impedance characteristics of glass based on the structural principle in discharge, it can be significant1y affected by frequency. Thus, this study verified the change in the characteristics of electromagnetic fields according to the change in frequency through a Maxwell's electromagnetic field simulation and examined the relationship between the change in the EEFL frequency and brightness by measuring the optical characteristics. In addition, the characteristics of the transformation of energy orbits were verified by investigating the characteristics of the wavelength according to the change in frequency through the OES.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.1
• /
• pp.1-9
• /
• 2003

In this paper, prototype of high-power-factor single-stage electronic ballast for fluorescent lamp is designed and implemented. A new low cost single stage high power factor electronic ballast for fluorescent lamps is based on integration of two-boost converter and LC type high frequency resonant inverter. The proposed ballast is combined by simple construction, because full bridge rectifier diode is eliminated and simple control circuit is applied. Boost converter operate in the voltage of positive and negative half cycle respectively at line frequency (60㎐), operation in discontinuous conduction mode performs high power factor. The experimental results show the good performance as PF 0.99, THD 15.4%, and CF 1.65 at output 63.5〔W〕.

• ALGAE
• /
• v.24 no.2
• /
• pp.121-127
• /
• 2009

The unicellular green alga, Haematococcus pluvialis, accumulates the highest level of astaxanthin among knownastaxanthi.n-producing organisms. Light is the most important factor to induce astaxanthin by H. pluvialis. BIue andred LEDs, whose ${\lambda}_{max}$'s are 470 and 665 nm, respectively, were used for internally illuminated light sources.Fluorescent lamps were also used for both internal and external illumination sources. The astaxanthin levels in thesevarious lighting systems were analyzed and compared each other. The cultures under internally illuminated LEDsaccumulaled 20% more astaxanthin than those under fluorescent lamp. Furthermore, LEDs generated much lessheat than the fluorescent lamps, which gives one more reason for the LEDs being a suitable internal Light source forastaxanthin induction. The results reported here would lead novel designs of photobioreactors with improvementsof illumination methods for high level of astaxanthm production. The maximum astaxanthin concentrations as wellas the astaxanthin yield per supplied photon were increased by at least 20% when blue or red LEDs were supplied.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1998.06b
• /
• pp.122-128
• /
• 1998

• Proceedings of the Optical Society of Korea Conference
• /
• 2007.07a
• /
• pp.321-322
• /
• 2007

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1997.10a
• /
• pp.18-20
• /
• 1997