• 제목/요약/키워드: electric resistance

검색결과 1,444건 처리시간 0.03초

고주파 전기 저항 용접부의 용접 결함 발생 빈도에 미치는 용접 입열 속도의 영향 (Effect of Heat Input Rate on the Weld Defect Formation during High Frequency Electric Resistance Welding)

  • 조윤희;김충명;김용석
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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    • pp.201-203
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    • 2000
  • In this study, effect of welding parameters on the defect density in the weldments produced by high frequency electric resistance welding process. The defect density measured by X-ray radiography showed a W-type curve as a function of heat input rate. The mechanisms of the such behavior were discussed based on the chemical compositions of the oxides formed at the weldments.

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Electric Battery Sensor의 Car Start State예측 알고리즘 개발을 위한 차량 전기 시뮬레이터 개발 (Developement of Vehicle Electric Simulator system for alorithm of Car Start State test)

  • 신상호;고국원;노희진
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2011년도 춘계학술논문집 1부
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    • pp.454-457
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    • 2011
  • 논문에서는 EEM 시뮬레이터를 개발하여 개발되어진 시뮬레이터를 Voltage, Current, Resistance의 데이터를 추출하고 실차를 이용하여 시동 테스트를 통한 자동차 시동시 순간적으로 흐르는 Voltage, Current, Resistance의 순간 변화량을 추출하여 과 각각의 특성을 비교하여 Battery의 SOC, SOH를 구하고 자동차의 Battery 를 획기적으로 관리할 수 있는 시뮬레이터를 개발하려 한다.

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石炭의 黑鉛性에 關한 硏究 (第1報) (Studies on the Electric Resistecna of Coals (1))

  • 오신섭;이석원
    • 대한화학회지
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    • 제5권1호
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    • pp.22-25
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    • 1961
  • The attempt to distinguish between graphite and domestic anthracite was means, especially electric resistance. The specific resistance values of various coals and graphites were determined by Wheaston Bridge equipped with more finely adjustable slide wire. The result of graphite was in the below of 0.08 ohm-cm and that of anthracite has $10^{-1}{\sim}10^1$ohm-cm range.

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삼상유도전동기 권선저항 측정이 효율 산출에 미치는 영향에 관한 연구 (A Study on the Measurement of the Winding Resistance Influences the Efficiency Evaluation of 3phase Induction Motors)

  • 강병국;김광민;이주
    • 조명전기설비학회논문지
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    • 제30권3호
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    • pp.73-78
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    • 2016
  • 3phase induction motor consumes 40% of national electric power. so It is one of the most important electric device for the national power policy. The efficiency measurement is carried out by IEC standards. After the temperature rise test, It's difficult to measure the winding resistance immediately. because of inertia and power cut-off time. Therefore, IEC standards suggest the measurement time. But during the measurement time, the winding temperature cools down. It causes the value of winding resistance is variable. Several conditions which possibly occurred by the measurement time of IEC 60034-1 are suggested. and The efficiency evaluation of 3phase induction motors is carried out by IEC 60034-2-1 with the several conditions. As the results, we find out the winding resistance rapidly goes down within 15 sec. so It proves that the winding resistance should be measured within 15 sec. for the efficiency evaluating of 3phase induction motor.

Coated Conductor에서의 퀜치 거동 (Quench Development in Coated Conductors)

  • 김혜림;박충렬;임성우;유승덕;오성용;현옥배
    • Progress in Superconductivity
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    • 제10권2호
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    • pp.149-154
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    • 2009
  • We measured and analyzed the quench development in coated conductor(CC) tapes. The CC was grown on hastelloy substrates and has an Ag protection layer. The tapes were subjected to simulated AC fault currents for quench development measurement. They were immersed in liquid nitrogen during the experiment. The quench resistance increased rapidly first, and the increase slowed down afterwards. It increased linearly with applied voltage at lower voltages, and depended less strongly on applied voltage at higher voltages. The resistance was compared with that of Au/YBCO films grown on sapphire substrates, and found to increase more monotonously than the latter. Data were analyzed quantitatively with the concept of heat transfer within the tape and the surrounding liquid nitrogen. A heat balance equation was derived and solved, taking into consideration temperature dependence of thermal parameters of the tapes. Solutions, together with values of thermal parameters taken from the literature, explained the data well. Cooling by liquid nitrogen affected the quench development considerably at lower applied voltages. Dependence on applied voltages could be also understood quantitatively.

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통전한 우드세라믹의 전기적 성질 (Electrical Properties of Woodceramics with Sending an Electric Current)

  • 오승원
    • Journal of the Korean Wood Science and Technology
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    • 제35권4호
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    • pp.9-13
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    • 2007
  • 소나무로 제조된 톱밥보드를 수지함치율을 달리하여 함침한 후 $650^{\circ}C$로 탄화하여 우드세라믹을 제조하고 통전하여 이들의 전기적 성질 및 표면온도를 측정하였다. 고정저항이 작을수록 낮은 전압으로 통전하여도 우드세라믹의 표면온도가 높음을 알 수 있었으며, 저항이 클수록 표면온도를 $70^{\circ}C$ 이상 올리기 위해서는 전압을 높게해야 할 것으로 판단된다. 또한 전압을 높게 했을 때 우드세라믹에 흐르는 전류, 전력 및 표면온도는 높게 나타났으며, 동일 전압 하에서는 목표온도가 높을수록 도달시간, 전류 및 전력을 증가하였다.