• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.37-40
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• 2002

Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in cable TV.

• Journal of IKEEE
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• v.19 no.1
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• pp.101-109
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• 2015

As the number of smartphone users grows, number of applications and the expected overall functionality in a smartphone grow simultaneously. With ever-so increasing expectations comes intense competition to squeeze in myriads of functions in a limited space that is only getting 'slimmer' by the year. In order to achieve this, companies often decrease the size of components in smartphones - battery connectors in particular. While they may fit, smaller battery connectors have their disadvantages due to the heat generated by the high current flow in the circuits. In collaborating with Korea's leading battery connector manufacturers, this research presents current issues and design concepts that should be considered when engineers design power connectors based on their electrical and thermal analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.69-74
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• 2014

Recently, many countries are researching and developing the various Electric Vehicle(EV) for reserving their natural environments and so on. But the charging time that is longer than the time of filling up the traditional engine vehicle will be the obstacles of spreading them. So, the other type EV is developed. It is the Battery Changeable EV. But there is not testing method for it. Especially, the defining of the durability evaluation for the couplers between battery and charger is very important because the couplers are changed very frequently. So, they may cause many faults and problems. Therefore, this study shows the definition of the durability procedure and the test is conducted with the equipment.

• Fire Science and Engineering
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• v.24 no.4
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• pp.104-108
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• 2010

This paper describes electrical fire on electric pad using carbon type hot wires. A carbon type hot wires electric pad is virtually impossible to connect hot wire as a method of electrical welding or soldering. In order to connect between hot wires, that has to splice carbon type material connector. If junction of hot wires was occurrence of poor connection on electric pad, it increase contact resistance on this junction point. With increasing contact resistance, junction of hot wires on electric pad generates local heating and finally leads to electrical fire. In this paper, we analyzed shape of damage in hot wires caused by electrical local heating and investigated fire cause on electric pad using by carbon type hot wires.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1214-1217
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• 2004

현재 전기용량의 국가표준은 1 kHz, 1592 Hz에서만 유지 및 보급이 되고 있다. 그러나 전기용량 및 임피던스를 측정하는 브리지와 LCR meter들은 비교적 넓은 주파수 범위에서 측정이 가능하도록 생산이 되고 있다. 따라서 이러한 기기들의 교정은 실제적으로 사용되고 있는 주파수 전 영역이 아닌 1 kHz 만 되고 있어서 완전한 교정이라고 할 수 없다. 본 논문에서는 이를 해결하기위하여 임피던스 analyzer의 one-port 측정기술을 사용하여 4-terminal-pair(이하 4TP) 전기용량 표준기 각각의 terminal에서 임피던스를 필요 주파수에서 측정하고, 측정된 임피던스 matrix를 이용하여 4TP의 transfer 어드미턴스와 출력임피던스를 계산 하였다.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E1
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• pp.29-38
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• 2007

A cylindrical tube connection that has a voltage difference and is separated electrically by an insulator was modelled. The penetration efficiencies of charged particles passing through the connector tube were investigated. Typically, as the particle size decreases and the applied voltage difference increases, the penetration efficiency decreases. To assess the effect of the electrode geometry, various lengths of electric insulator and aerosol flow rate with a fixed tube length and tube diameter were used when calculating penetration efficiencies. The comparison of penetration efficiencies for various electrode geometry setups suggests that the penetration efficiency can be described as a function of the product of applied voltage and electrical mobility of charged particles. The diffusion loss from this and previous studies are compared. Further, an explicit form for penetration efficiency is provided as a function of a new non-dimensional parameter, $Es(=Z_pV/U_{avg}W);\;P_{es}=0.2{\cdot}{\exp}(-Es/0.6342)+0.8{\cdot}{\exp}(-Es/4.7914)$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.450-451
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• 2008

In this paper, we have designed the Anti-Reflection (AR) coating for 850, 1310 nm(multi type) and 1310, 1550 nm(multi type) wavelength ranges on the ferrule facet of special optical connector. The reflectance of the AR coated ferrule facet is designed under 5% for 850, 1310 nm(multi type) and 1310, 1550 nm (multi type). AR thin film was deposited by ion- assisted deposition in low temperature. The average return loss of the AR coated ferrule facet is 47.1 dB.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.90-94
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• 2013

A low loss power dividing switch in a indoor microwave power distribution system is proposed and designed with a various power dividing ratio. Switching characteristics are analyzed by use of the S-parameter of the switch. Newly proposed switch showed a very low return loss less than -30dB at the operating frequency of 2.45GHz. Three kinds of the switch in which we take out individually 1/2, 1/3 and 1/4 of the input power were fabricated, and measured the delivered, transmitted, and return loss power ratio. Simulated results showed that the lower power ratio is, the better accurate operating performance shows. This switch can switch the input power from 4.5% to 58% with the variance of 5% output power. The experimental results are in good agreement with the simulation within the return loss of 1%.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.835-837
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• 1998

Current lead plays the part of connector between ambient temperature and liquid helium superconducting magnet. Having zero resistance characteristic, it is expected that HTS has very low thermal conductivity and generate no joule heat when fabricated to current lead. In particular, among the HTS meterials, HTS tape has high Jc and Ag-sheath of tape plays the part of stabilizer, but it has too poor mechanical strength to be applied and when fabricated as long length tape, it has tendency to decline Jc seriously. In this study, we fabricated Bi-2223 multifilamentary tapes and then made current lead with stacking type using them. Through this work, we conclude that the defect of HTS long length tape is decreased by addition the number of stacking tape and that current lead is able to operate more stably by minimizing the gap of tapes.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.30-36
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• 2009

This paper aims at the precursor analysis and DB development of electrical fires based on thermal and current signals for partial disconnection and poor contact on electric wires through experiments and simulations. Also, DB system required for developing the precursor DB with these data was studied and designed. Firstly, in case of partial disconnection, characteristics were derived and analyzed by experiment and electrical-thermal finite element method(Flux 3D) on the model wires which consist of VCTF and IV electric wires. Based on the characteristics, About 351 partial disconnection precursor patterns were generated by the thermal analysis for electric wire according to deterioration time under normal state and 200% overload state of rated current. Secondly, in order to develop poor contact precursor patterns, temperature value and the current signal were considered. In simulating the poor contact situation on connector area of MCCB, connection torque was changed. Through the experimental analysis, about 251 poor contact precursor patterns were generated. Finally, Using thermal precursor patterns obtained by partial disconnection and poor contact, electrical fire thermal precursor DB was developed.