• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.834-838
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• 2004

This paper presents the structure of a dimming control system for multiple fluorescent lamps. The dimming control system is composed of a phase angle controller, a transducer, and dimmable ballasts. In these ballasts, dimming control is achieved by varying the switching frequency that is controlled by the external DC level.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.10
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• pp.492-496
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• 2005

An electronic ballast with automatic identification between HPS and MH lamps is proposed in this paper. The behavior of the lamp impedance is studied at both cold-starting and warm-starting. Lamp identification is carried out by taking into account the rate of impedance changing at constant current driving mode just after ignition. The ballast consists of 8-bit microcontroller and LCC resonant inverter.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.667-669
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• 2008

With the advancements or LEDs and lasers in projection display applications, arc lamps still provide the most cost effective solution to high brightness display systems. When will arc lamps become obsolete, will be of great importance today and tomorrow? Given the fact that traditional elliptical and parabolic reflectors had been around for decades; Wavien's new dual paraboloid reflector (DPR) technology with its unique imaging property enhances various aspects of the arc lamp performance will shed some light to this question. In this talk, various applications that are feasible today and anticipated needs of tomorrow will be presented.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1023-1026
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• 2003

An electronic ballast for driving automotive HID lamps is presented. The circuit topology is composed of a fly back converter, a Ful bridge inverter, and an igniter. A prototype was developed and tested on a 35W lamp with a 12V input voltage. To avoiding the acoustic resonance, the full bridge inverter is operated at 250Hz and provided a squared-wave voltage source to the lamp. The transient and steady state characteristics of the tested HID lamps are measured and analyzed.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.99-102
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• 2002

T5 28 Watt 형황등용 전자식 안정기에 대한 제품설계 및 램프 수명 관계를 고찰하고 정확한 이해를 토대로 각 제품의 국제적인 기술 기준(IEC60928, 60929)으로 Fault Condition 시험, 램프수명 테스트, 전자파장해 시험을 위주로 시험하여 분석하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.944-947
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• 2007

The electrooptic characteristics of 32-inch multichannel-structured, mercury-type flat fluorescent lamps have been investigated in detail. The luminance and the lamp current/voltage have been monitored by changing the driving conditions such as duty ratio, backlight conditions. It was found that the efficiency became the maximum at the duty ratio of 50 % with a nearby metal plate.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.965-968
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• 2007

The effect of the modification of the front surfaces of flat fluorescent lamps (FFLs) on the light-output distribution has been investigated by using a ray tracing method and several kinds of microlenses. It was found that microlenses have substantial effects on the light-output distribution, which might be used to reduce the number of optical films in the FFL-backlight unit for LCD applications.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.118-123
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• 2007

The emitting structure of multi-channel-type flat fluorescent lamps (FFLs) combined by a lenticular-lens-patterned diffuser plate was optimized by the ray tracing technique. The optimal parameters such as the distance between the channels of the FFL and the distance between the FFL and the diffuser plate were suggested from the viewpoint of the luminance uniformity. The best luminance uniformity, which was higher than 90%, was obtained at the channel distance of 4 mm and the distance of 12.5 mm between the FFL and the patterned diffuser plate.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1492-1495
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• 2005

This paper presents a study on the modeling on the dimming control of electronic fluorescent lamp. The resulted models of the lamps were applied the two dimming control methods, one is the variable switching frequence and the other is the variable dc link voltage method. And the comparison of the dimming characteristics between the two methods was presented. Theoretical predictions were verified the experimental results on a 100w electrodeless fluorescent lamp.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.108-112
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• 2017

High-intensity-discharge lamps are widely utilized in outdoor and indoor lighting circumstances that need high luminance. In lighting applications for MHD lamps, the size of the lamp ballast circuit is an important factor and should be as small as possible. The electronic ballast for MHD lamps is superior to the electromagnetic(EM) ballast in that it saves energy, and has smaller volume and lighter weight. In this paper, highly efficient cost-effective and small sized electronic ballast for Metal Halide Lamp with high power factor using Digital Signal Processor are proposed. The proposed electronic ballast for MHD lamps combines a boost PFC converter with a half-bridge inverter, the algorithms of the power factor correction and ballast control were implemented using the TI's TMS320LF2406 CPU. Experimental results validate the ballast is also useful and reasonably suggested.