• 제목/요약/키워드: Current Relation

검색결과 1,539건 처리시간 0.026초

Eddy current 동력계의 부하와 와전류의 직진성 관련 연구 (Linearity study for the field coil current and the load of eddy current dynamometer)

  • 문병수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.66-72
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    • 2000
  • Commercial eddy current dynamometers control the torque of ratating body (poer supply machine) with the field coil current being operated as a braking force. In this paper, we studied about the relation between the field coil current and the torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer, it is linear relation between the brake force measured from the torque meter (e.g. load cell, strain gage or spring balance etc.) which is installed at the case of dynamometer and the multiply of shaft rpm by the square of field coil current (N$\times$Ia2). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measures the torque of rotating body without special torque measuring devices.

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와전류 동력계에서 계자전류를 이용한 부하토크의 측정에 관한 연구 (A Study on the Measurement of Load Torque by the Field Coil Current in an Eddy Current Dynamometer)

  • 문병수;이응석;이형석
    • 한국정밀공학회지
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    • 제18권10호
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    • pp.84-92
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    • 2001
  • Commercial eddy current dynamometers control the torque of rotating body, power supply machine, with the field coil current being operated as a braking force. In this paper, we studied the relation between field coil current and torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer it is linear relation between the brake force measured from a torque meter which is installed at the case of dynamometer and the multiplied shaft rpm by the squares of field coil current (N$\times$I$^2$). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of the eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measure the torque of rotating body without a torque measuring device. such as load cell.

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크랙에 의한 고온 초전도체 테이프의 임계전류 특성변화 (The variation of critical current by the formation of crack in a high-temperature superconducting tape)

  • 박을주;설승윤
    • 한국초전도ㆍ저온공학회논문지
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    • 제4권1호
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    • pp.73-77
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    • 2002
  • The variation of critical current by the formation of crack in a high temperature super-conducting tape was studied by experimental and numerical analyses. The current-voltage relation of HTS tape is measured by the four-point measurement method. Numerical analyses are used to solve two dimensional heat conduction equation, considering the temperature distribution. By comparing current-voltage relation of experimental and numerical results, the validity of numerical method is verified.

송전선로에서 전류와 자계의 상관관계 분석 (Analysis on the relation between electric current and magnetic field near transmission lines)

  • 조성배;이은웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.3-5
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    • 1997
  • The relation between electric current and magnetic field under three overhead transmission lines being operated was studied. It was examined for a difference each other in comparison with calculated value and measured value for current, magnetic field. With magnetic field equations made out, The magnetic field distribution around transmission lines had made to figure out with easy by load electric current value. Additionally, we are going to describe the distribution curve of magnetic exposure volume for KEPCO's T/L.

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저임피던스 케이블의 허용전류에 대한 연구 (A Study on Permissible Current of Low Impedance Cable)

  • 김동식;박복기;이종찬;이관우;박대희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.513-515
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    • 1999
  • In this study, we evaluated the relation of the test and theory of low impedance cable As the result We could obtained the result in accordance the test with theory in 85 ~ 95% tolerance . Test method measured the relation of the current and temperature of cable jacket in using CT to put in 3 phase AC current simultationiously. The current and temperature of it was calculated in according to JCS- l68D

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전계를 이용한 팬케이크 권선으로 제작되는 마그넷의 임계전류 산정 (Critical Current Estimation of HTS Magnets by using Field Dependent E-J Relation)

  • 강명훈;구명환;이희준;차귀수
    • 전기학회논문지
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    • 제58권3호
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    • pp.502-508
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    • 2009
  • The method to determine the operating current of HTS magnets needs to be different from that of LTS magnets. This paper presented estimation of the critical current of pancake windings. The pancake windings can be excited by a single power source or by multiple power sources. Critical currents were determined by using field dependent E-J relation. For the better estimation of the critical current, a new method to define the magnetic field of the HTS wire has been proposed. Calculated critical currents of pancake windings were compared with measured ones of the HTS BSCCO magnet consisting of 10 pancake windings. According to the test results, the estimated critical currents of pancake windings agreed well with that of measured ones. Effects of the single and multiple power source excitation on the critical currents have been also examined.

Current-voltage Characteristics of Ceramics with Positive Temperature Coefficient of Resistance

  • Li, Yong-Gen;Cho, Sung-Gurl
    • 한국세라믹학회지
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    • 제40권10호
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    • pp.921-924
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    • 2003
  • A current-voltage relation for Positive Temperature Coefficient of Resistance (PTCR) ceramic was derived and compared with the experimental data. The new current-voltage relation was developed based on Heywangs double Schottky barrier model and a bias distribution across the grain boundary. The voltage limitation V < 4${\Phi}$$\sub$b/ suggested by Heywang is no longer necessary in the new expression for the voltage dependence of the resistance. The pulsed voltages were applied to the PTCR ceramic specimen in order to avoid possible temperature variation during the measurement.

관내연선도체 초전도 자석에서 루프 전류의 형서에 관한 연구 (Investigation on the loop current in the CICC superconducting magnet)

  • 김석호;정상권
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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    • pp.69-72
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    • 1999
  • During the fast current and field ramp up experiment with CICC (Cable-In-Conduit Conductor) non-insulated 3 strand superconducting magnet, the unbalanced current distribution associated with the loop current has been obtained directly from the shunt resistor voltage data. To explain the generation of the loop current during the current ramp up, the steady-state three strand loop current model was proposed. This model gives an explanation for the relation between the loop current and the relation between the loop current and the twist geometry of the strands. According to this model, the twist geometry of the strand has significant influence on the generation of the loop current especially in the large superconducting magnet.

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저전력 무선통신 모뎀 구현용 전류기억소자 성능개선 (Performance Improvement of Current Memory for Low Power Wireless Communication MODEM)

  • 김성권
    • 한국전자통신학회논문지
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    • 제3권2호
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    • pp.79-85
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    • 2008
  • 다양한 무선통신 방식이 출현함에 따라 배터리 수명과, 저전력 동작이 중요시되면서 무선 통신용 LSI는 SI circuit을 이용하는 analog current-mode signal processing을 주목하고 있다. 그러나 SI (Switched-Current) circuit을 구성하는 current memory는 clock-feedthrough의 문제점을 갖는다. 본 논문에서는 current memory의 문제점인 clock-feedthrough의 일반적인 해결방안으로 CMOS switch의 연결을 검토하고, current memory 성능 개선의 설계방안을 제안하기 위하여 CMOS switch 간의 width의 관계를 도출하고자 한다. Simulation 결과, memory MOS의 width가 20um, input current와 bias current의 ratio가 0.3, CMOS switch nMOS의 width가 2~6um일 경우에 CMOS switch 간의 width는 $W_{Mp}=5.62W_{Mn}+1.6$의 관계로 정의되고, CMOS switch nMOS의 width가 6~10um일 경우에 CMOS switch 간의 width는 $W_{Mp}=2.05W_{Mn}+23$의 관계로 정의되는 것을 확인하였다. 이 때 정의된 MOS transistor의 관계는 memory MOS의 성능향상을 위한 설계에 유용한 지침이 될 것으로 기대된다.

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일부 도시 노인 건강 관리 계획을 위한 기초조사-시내 응암동 할머니회를 대상으로- (A Survey on Current Health Care Activities of the Aged, in a Selected Urban Area -Female Aged, Ungamdong, Seoul-)

  • You Kye-Ai;Han Jung-Suk;Lee Choon-Ai;Hahn Yoon-Bok;Han Sang-Im
    • 대한간호
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    • 제20권3호통권111호
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    • pp.49-57
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    • 1981
  • Current population trends, marked by an increasing accumulation of old members, must be followed by major adjustment in socioeconomic planning since our traditional family structure has been changing as a result of scientific and sociologic advances. Welf

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