• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.159-162
• /
• 2000

In his paper the principle of using coreless printed circuit board (PCB) based transformer in 2.3MHz, 12W class ZVS Forward DC-DC converter has been successfully demonstrated. With no core loss coreless PCB transformer and inductor are found to have favorable characteristics at high frequency operations. The maximum power conversion efficiency is 80% Even for high operating frequency an efficiency greater than 70% can be obtained with under 0.7% regulation error.

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.535-538
• /
• 2000

There are several electricity applied sterilizers such as sterilizer with high frequency sterilizer with ozone sterilizer with high voltage and so on Those sterilizers feature "because there is no chemical process there is no secondly environmental pollution" At the power conversion part ZVS and ZCS methods have been used that it results in reduced switching loss miniaturized size and lightened weight, Besides the current in the device is smaller than that of existing method. Thus it is expected that the cost of sterilization process when quality of the device is measured by power consumption will be reduced.e reduced.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.350-354
• /
• 2004

This paper presents theoretical and practical details about the design, implementation, and performance of a series resonant do-to-dc converter using planar magnetics. Result of sinusoidal analysis are used to predict the voltage gain and conversion efficiency. The performance of a prototype converter is presented including the efficiency measurement and theoretical loss breakdown.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.4B no.1
• /
• pp.20-23
• /
• 2004

BLDCMs are widely used in many industries. In certain specialized areas, they need to have high efficiency, high power rate and produce a low volume of noise, etc. In this study, a new type of slotless BLDCM is proposed that has no cogging torque, low iron loss and low volume as compared to commonly used BLDCMs. With a high performance magnet and coreless compact winding structure similar to those employed in linear synchronous motors, motor volume is reduced. The proposed motor has been put been through various experiments arid has demonstrated acceptable results for industry applications.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.294-297
• /
• 2003

This paper describes the design and the simulation of a frequency doubler for millimeter-wave applications using distributed amplifier technology. The designed frequency multiplier has 10% bandwidth at 58GHz output. This paper investigates nonlinear analysis of pHEMT frequency multipliers utilizing AM-AM and AM-PM distortion characteristics of frequency doubler. The conversion loss is 2.1dB and harmonic suppression is larger than 18.6dBc with 5dBm input power

• 전기의세계
• /
• v.30 no.10
• /
• pp.655-661
• /
• 1981

The concentrating solar module with high concentration ratio(320)has been studied.in this paper. The solar module was composed of the EMVJ solar cell, (Fresnel Lens-DCPC)concentrator and heat sink, and was measured by using the PASTF system. The experimental result and the result analysis for the individual item of the module were as f ollows; (1) The conversion efficiency of the module was 8.3%. (2) The optical efficiency of the concentrator was 46.5% (DCPC; 84.8%, Fresnel Lens; 54.8%). (3) The thermal loss of the solar cell was 4.9%. And methods for the further improvement of the concentrating solar module efficiency have been suggested.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2000.11a
• /
• pp.161-175
• /
• 2000

This study includes the fundamental planning of the sectoral management technology in energy distribution system so that the industry itself would be willing to participate for the effective energy conservation in its own sector. Furthermore guidlines for the effective energy management techniques have been presented by first analyzing the energy consumption structures, the energy loss problems, the energy conservation status and the technology demands, and second classifying, according to the energy distribution system, the energy source management, the energy generation & conversion facilities, the energy transportation ＆ storage facilities, the energy consumming facilities and the waste energy management, etc. in the industrial sector.

• Proceedings of the IEEK Conference
• /
• 2001.06e
• /
• pp.237-240
• /
• 2001

There are several electricity applied sterilizers such as sterilizer with high frequency, sterilizer with ozone, sterilizer with high voltage, and so on. Those sterilizers feature “because there is no chemical process, there is no secondly environmental pollution” At the power conversion part, AVS and ZCS methods have been used that it results in reduced switching loss, miniaturized size, and lightened weight. Besides, the current in the device is smaller than that of existing method. Thus, it is expected that the cost of sterilization process, when quality of the device is measured by power consumption, will be reduced.

• Proceedings of the IEEK Conference
• /
• 2007.07a
• /
• pp.129-130
• /
• 2007

I/Q demodulator is designed using RC-CR quadrature divider with two balanced mixer for WLAN applications. The I/Q demodulator has low power dissipation, good I/Q mismatch, a good isolation and conversion loss. The measured results shows close agreement with the predicted performance.

• Korean Membrane Journal
• /
• v.9 no.1
• /
• pp.34-42
• /
• 2007

A perovskite-type ($La_{0.6}Sr_{0.4}Ti_{0.2}Fe_{0.8}O_{3-{\delta}}$) dense ceramic membrane was prepared by polymerized complex method, using citric acid as a chelating agent and ethylene glycol as an organic stabilizer. Effect of Ti addition on lanthanum-strontium ferrite mixed conductor was investigated by evaluating the thermal expansion coefficient, the oxygen flux, the electrical conductivity, and the phase stability. The thermal expansion coefficient in air was $21.19\;{\times}\;10^{-6}/K$ at 473 to 1,223 K. At the oxygen partial pressure of 0.21 atm ($20%\;O_2$), the electrical conductivity increased with temperature and then decreased after 973 K. The decrement in electrical conductivity at high temperatures was explained by a loss of the lattice oxygen. The oxygen flux increased with temperature and was $0.17\;mL/cm^2{\cdot}min$ at 1,223 K. From the temperature-dependent oxygen flux data, the activation energy of oxygen ion conduction was calculated and was 80.5 kJ/mol at 1,073 to 1,223 K. Also, the Ti-added lanthanum-strontium ferrite mixed conductor was structurally and chemically stable after 450 hours long-term test at 1,173 K.