• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.641-644
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• 2007

The electro-mechanical mercury relay is used as an auxiliary relay of power facility because it is superior to operating time and no-bounce. So the KEPCO had used the mercury relay for operating HVDC(High Voltage Direct Current) system. But it has many problems with facility operation by occurrence of mercury evaporation, held contact point and malfunction according to long term use, furthermore it is forbidden to produce for fear of environmental pollution in 2002. This paper presents the no-mercury relay development, comparison test and application.

• ETRI Journal
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• v.45 no.3
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• pp.543-550
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• 2023

Electrostatic discharge (ESD) testing for human body model tests is an essential part of the reliability evaluation of electronic/electrical devices and components. However, global environmental concerns have called for the need to replace the mercury-wetted relay switches, which have been used in ESD testers. Therefore, herein, we propose an ESD tester using metal oxide semiconductor-controlled thyristor (MCT) devices with a significantly higher rising rate of anode current (di/dt) characteristics. These MCTs, which have a breakdown voltage beyond 3000 V, were developed through an in-house foundry. As a replacement for the existing mercury relays, the proposed ESD tester with the developed MCT satisfies all the requirements stipulated in the JS-001 standard for conditions at or below 2000 V. Moreover, unlike traditional relays, the proposed ESD tester does not generate resonance; therefore, no additional circuitry is required for resonant removal. To the best of our knowledge, the proposed ESD tester is the first study to meet the JS-001 specification by applying a new switch instead of an existing mercury-wetted relay.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.425-426
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• 2006

수은접점형 전기기계식 릴레이는 동작 속도와 no-bounce 특성이 우수하여 전력설비 보조 릴레이로 많이 사용되고 있으며 우리 한국전력공사 직류송전방식 HVDC 설비에도 설치되어 운영 중이다. 그러나 수은접점은 장기 사용시 열화현상으로 수은 증발, 접점 고착과 뭉침현상에 의한 빈번한 오동작 발생 및 환경오염 우려로 2002년 전 세계적으로 생산중단 되어 설비운영상 문제점으로 부각되고 있다. 본 논문은 운영중인 설비유지보수를 위하여 동일한 기능수행이 가능한 무수은형 카드릴레이 개발과정, 비교시험 및 설치운영에 대한 방안에 대하여 고찰하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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• pp.623-631
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• 2011

Light emitting diodes (LEDs) which can produce uniform luminescence need a very difficult and complex procedure because LEDs have strong and straight optical property. One of the major parameters for LED production is the determination of the viewing angle. However, in the present, there is still no available production technology to measure LED viewing angle and optical property. In this study, we developed a five-side LED viewing angle and optical property measurement system, having a source meter that uses a high speed switching photo relay instead of a mercury relay. This new measurement system can measure the viewing angle at a very high accuracy of ${\pm}0.66^{\circ}$. This new technology presents a great potential for fast and reliable LED mass production, which can significantly cut down the cost from savings in production time.