• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2332-2334
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• 2004

A high bandwidth watt-converter, based on an inexpensive, commercially available, standard IC package, is described that covers a frequency ranges from DC to 100 kHz. The new resistive shunt for a wide-band frequency current measurement of the watt-converter was developed. The converter will use application in accurate power measurement under distorted and high frequency conditions. The advantages of the watt-converter are its simplicity, low cost and fast response time.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.10
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• pp.597-601
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• 2004

A high bandwidth watt-converter, based on an inexpensive, commercially available, standard IC package, is described that covers a frequency ranges from DC to 100 kHz. The new resistive shunt for a wide-band frequency current measurement of the watt-converter was developed. The converter will use application in accurate power measurement under distorted and high frequency conditions. The advantages of the proposed watt-converter are its simplicity, low cost and fast response time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.8
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• pp.805-808
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• 2011

This paper presents a design of high-efficiency and high-power class E power transmitter. The transmitter is composed of 300 Watt class E power amplifier and AC-DC converter. The AC-DC converter converts 220 V and 60 Hz AC to a 290 V DC. The generated DC voltage is directly applied to a bias of the class E power amplifier. Because the converter does not have DC-DC converter unit, it has very high conversion efficiency of about 98.03 %. To minimize the loss at the output of the power amplifier, high-Q inductor was implemented and deployed to the output resonant circuit. As a result, the 13.56 MHz class E power amplifier has a high power-added efficiency of 84.2 % at the peak output power of 323.6 W. The overall efficiency of class E power transmitter, including the AC-DC converter, is as high as 82.87 %.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1845-1849
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• 2010

We have proposed and fabricated a Buck-Boost DC to DC Converter for Thermoelectric generator (TEG) with constant output voltage suitable for battery chargers or constant voltage supplies in the range of several watt. The experimental and simulation results have shown that the proposed method allows stable operation with maximum 86% power transfer efficiency. The proposed circuit has a merit in cost and miniaturization of a system compared to conventional MPPT algorithms, because the proposed method adopts only analog circuit without DSP or micro controller unit for calculating peak power point by iterative methods.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.443-452
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• 2002

A new phase shift full bridge (PSFB) converter with serially connected two transformers for telecommunication equipments of several hundred watts is proposed. The main features of the proposed converter are a wide input voltage range, an easiness to meet the requirement for zero voltage switching (ZVS) condition at a light load, and a small output voltage ripple. Furthermore, the serially connected two transformers can replace both a main transformer and an output inductor since the two transformers act as not only a main transformer but an output inductor by turns. Therefore, there is no need to use an output inductor, then the proposed converter features high power density. A mode analysis, design equations through a large signal modeling, and experimental results are presented to verify the validity of the proposed converter.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.4
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• pp.185-192
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• 2005

This paper proposes a DRMS(Distribution Remote Management System) which can enhance highly the economics of automatic metering system and the power quality supplied to the electric customer improving the efficiency of the meter reading, voltage management and load management work by realizing the remote meter reading, the remote voltage management and the remote load management based on the ADWHM(Advanced Digital Watt Hour Meter). The DRMS is designed so that the voltage management and load management work in remote site can be processed by collecting the voltage pattern and current pattern as well as watt hour data from all ADWHMs one time every month regularly or from special ADWHMS several time irregularly, A new on-line voltage and load management strategy based on the ADWHM is designed by analyzing the existing voltage management and load management process. Also, DRMS is designed so that watt-hour data, voltage pattern data, load pattern data and power factor data can be collected selectively according to the selection of user to assist effectively the methodology. Remote management program and database of the DRMS are implemented based on Visual C++, MFC and database library of MS. Also, DRMS is designed so as to communicate with the ADWHM using RS232C-TCP/IP converter and ADSL. The effectiveness of the remote metering function is proven by collecting and analyzing the data after ADWHMs installed in any site. The developed strategy and program also is verified through the simulation of voltage management and load management.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2789-2791
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• 1999

This paper deals with the design of the HPS electronic ballast, which consists of the ignitor for turning-up and the resonant converter for driving the lamp. Also it contains Power Factor Controller to improve the electronic efficiencies such as power factor, crest factor, low distortion, etc. To make this circuit, it is necessary to simulate it on the computer before we implement it actually. In this paper, we try to modelize the HPS lamp and ballast, and have experiments with 150 watt-HPS lamp from Kwangjunsa.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.107-110
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• 2000

This paper deals with the design of the electronic ballast for high pressure sodium lamp, which consists of the ignitor and the resonant converter for driving the lamp. Also it contains PFC(Power Factor Controller) to improve such as power factor, low distortion etc. In this paper, we design the electronic ballast for the 150 watt high pressure sodium lamp.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.459-462
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• 2005

Recently, the PDP is the most remarkable media for a next generation display device. But the PDP is a high power consumption device. It is to required a high efficiency power supply. We reported the experimental result the high efficiency PDP power supply for 550w class. The proposed converter is quasi-resonant flyback topology, it achieves soft-switching in the single-switch flyback converter. As a result, we realize to very high efficiency power supply for PDP of 95% at 400v dc input and 550Watt output.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.103-107
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• 2011

In this paper, a method is proposed to improve power factor and the input current THD in LED driver circuit. The researched circuit consists of a valley-fill circuit and boosting inductor and a Buck converter. Valley-fill circuit is a passive PFC and simplified structure, the buck converter is operated with current feedback. The switching frequency is 50KHz in LED driver circuit and LED forward current is constant. A valley-fill type PFC circuit for LED driver(15Watt) has been implemented, and the validity of proposed method is shown by is simulation and experimental result.