• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.190-190
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• 2009

전자산업에의 필수인 커패시터는 소형화, 저저항, 고전압을 향한 추세가 늘고 있으며, 이외에도 고전압 전원, 고전압 회로 등 중전기기에 필요한 고전압, 고용량 커패시터가 사용되고 있다. 중전기기에 사용되는 커패시터는 기기에 따라 틀리지만 내전압이 보통 10kV 이상이고 정전용량이 500pF 안팎이며, 대부분 외국에서 수입에 의존하고 있는 실정이다. 본 연구에서는 $Nb_2O_5$를 2mol% 첨가한 $BaTiO_3$를 일반적인 고상 소결법으로 제조하고 성형 시 crack을 방지하기 위해 binder 및 plasticizer를 사용하였으며, binder 첨가량에 따른 성형밀도를 측정하여 최적의 binder양을 선택하였다. 성형 밀도가 떨어짐에 따라 절연파괴강도가 낮아지기 때문에 성형 밀도를 높이기 위해 CIP를 하였으며, 소결후 capacitance와 d-factor를 측정하여 수치가 허용 범위에 들어 올 경우 전극을 형성하고 표면파괴를 방지하기 위하여 epoxy로 표면코팅을 하였다. DC 60kV용 Hi-pot tester를 사용하여 15kV까지 선형적으로 증가시켜 내전압 테스트를 실시하였으며, 제조 된 커패시터 중 몇 개의 sample을 SEM 및 XRD를 사용하여 미세구조와 결정상을 조사하였다.

• 전기의세계
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• v.39 no.3
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• pp.15-20
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• 1990

GIS에서의 유한요소법을 이용한 전계계산의 적용례를 기술하면 GIS의 절연성능향상 및 고신뢰성을 위해서는 정도높은 전계계산 수단이 필요하며 GIS와 같은 고전압 전력기기의 절연설계시에는 정전계계산기술을 적극적으로 활용, 고신뢰성의 중전기를 생산공급하여, 양질의 전력공급 및 계통의 안정화에 더욱 공헌하고자 한다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.181-182
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• 2011

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.7-12
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• 2000

As an essential technology for the FED, VFD and PDP packaging having merits of no glass frit and no glass tube usage, two sodalime glass substrates were electrostatically-bonded in a vacuum environment, and the bond properties were compared with the case of bonding in atmosphere. The glass wafer pairs bonded in vacuum using a-Si interlayer had a relatively lower bond strength than the ones bonded in atmosphere under same bonding conditions (temperature and voltage). And the bond strength was increased in the case of oxygen ambient. Through the XPS and SIMS analyses fur the surface region of a-silicon and bulk glass, it might be concluded that the lower bonding strength was originated from the inactive silicon oxide growth occurred during the electrostatic bonding process due to oxygen deficiency in vacuum.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.261-265
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• 2005

This paper describes the DC-DC Converter for Ancillary Power Supply in Hybrid Electric Vehicle. DC-DC Converter is used for charging 12V auxiliary battery supplying electric power to head ramp, audio, ECU etc in automobiles. used DC-DC Converter Topology is PS-ZVS FB(Phase Shifted Zero Voltage Switching Full-Bridge) to reduce switching loss and EMI noise induced by high frequency operating condition. And For easy compensation and stable system response characteristic, current mode control method including slope compensation is employed. Constant current / constant voltage charging control method guarantee stable electric charging of auxiliary battery. Simulation toll PSIM6.0 is used for initial circuit parameter settings and H/W debuging. Thermal problems of Switching components in DC-DC Converter is improved by using Thermo Tracer.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.529-536
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• 2013

Lack of proper amount of sun lights and wind strength which are major factors of solar power and wind power system may cause poor electric power generation and decrease the lifetime of batteries that are major energy saving units. Because the PCS, which is essential in solar and wind power system, for small power generation system has been rarely developed an efficient and stable PCS for small power generation system is highly required. In this paper, we design a new constant current/constant voltage type hybrid PCS by which stand alone/grid connected operation with commercial power system is available and implement the designed PCS as a protype for performance verification.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.3
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• pp.351-358
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• 2014

In this study, we are a proposed system that could control a multi-functional welder of the current, voltage of the crater, gas control, the wire feeder's driven, the constant voltage output control, high frequency control, rated current control and the ARC welding control etc., using the mobile-based smart phone. Approximately 90% of user of proposed system are very useful in multi-function welder in their task responded and rest of 10% of the answers don't need it. 30% answered in 90% of the multi-function welding machine according to age group using a smart phone utilizing this "very difficult" at investigated. However, the use of smart phones is gradually lower the user's age group can be seen that effective.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.305-312
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• 2016

Modern embedded systems are typically operated by the rechargeable batteries in our daily life. Since charge of batteries is considered as an time consuming task, there have been extensive efforts to manage the charge time from the perspective of materials, circuits, and systems. Estimation of battery charge time is one of the essential information to design the charge circuitry. A compact macro model for the constant-current and constant-voltage charge protocol was recently introduced, which gives us a quick estimation of charge time with similar shape to the famous Peukert's law for discharge time estimation. The CC-CV charging protocol is widely used for Lithium-based batteries and Lead-acid batteries. In this paper, we characterize the lead-acid battery by measurement to extract the model coefficients, which was not covered by the previous studies. By our proposed model, the key coefficient Kcc results in 1.18-1.31, which is little bit higher than that of Lithium batteries. The accuracy of our model is within the range of ${\pm}10%$ error, which is compatible with the other studies such as Peukert's law.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.187-187
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• 2011

최근 디스플레이 산업과 태양전지 등의 이차 전지 산업이 발달함에 따라 원가절감과 공정단계의 단순화를 위하여 다이렉트 패터닝 인쇄에 대한 연구가 관심을 받고 있으며, 나노전자부품 제작이 요구되는 전기/전자 소자들은 수백 nm에서부터 수십 ${\mu}$m 수준까지 다양한 해상도의 패턴으로 구성되므로 미세패턴이 가능한 정전수력학 잉크젯프린팅 방식은 기존의 인쇄 방식과 달리, 정전기력을 이용하여 인쇄를 하는 방식으로, 수KV의 고전압을 인가하여 잉크를 대전시키고, 대전된 잉크는 대부의 전기적 반발력에 의해 액적이나 액실로 분열하게 된다. 전하를 띤 액적 또는 액실은 정전기력을 받아 기판 쪽으로 이동을 하게 되는데, 이때 액적의 전하량에 의해 액적의 이동속도와 이동경로가 영향을 받게 된다. 본 연구에서는 잉크의 전기전도도에 따른 액적의 전하량을 계산하여 전기전도도와 액적의 전하량과의 관계를 ANASYS 시뮬레이션과 운동경로 분석을 통해 확인하였다. 전기전도도가 0.307s/m~5.6s/m인 잉크에 따른 액적의 전하량을 계산하였으며, 전기전도도가 변화에 따라. 전하량이 $0.5{\times}10^{-13}C{\sim}2.5{\times}10^{-13}C$ 으로 변화하는 것을 확인하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.1-6
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• 2005

This paper studies the OF-LED(Optical Fiber-LED) illuminated display board system for energy saving. The OF-LED illuminated display board system has PV module, batteries, charge 8t discharge system and dynamic full color display controller. Both maximum power point tracker (MPPT) and constant current & constant voltage controls (CCVC) are used to govern the charging system. This system. improves the charging efficiency of battery. The system is compact and operates only by PV except the rainy days when the sun is unfavorable. in the system display control and charging-discharging control by on-chip microprocessor are simultaneously carried out. To verify the unposed system, me simulation and experiment results show the operating characteristics with a laboratory prototype.