• 제목/요약/키워드: Magnetic Contact

검색결과 417건 처리시간 0.031초

자기장학 누설자속법을 응용한 직류전류계측법에 관한 연구 (A Study on Direct Current Measurement Using Magneto-Optical LMF Method)

  • 이진이
    • 비파괴검사학회지
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    • 제24권6호
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    • pp.566-572
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    • 2004
  • 금속성 도선 뿐 아니라 기상 또는 액상의 직류전류를 계측하기 위해서는 비접촉으로 전류를 측정할 필요가 있다. 본 논문은 직류전류를 비접촉으로 계측하기 위한 방법 중 하나로써 패러데이효과와 누설자속을 이용하는 방법을 제안하고, 이론적 고찰 및 실험적 검증결과를 보고한다. 공극을 가진 강자성체 코어를 1차 코일에 의하여 자화하면, 공극 주위에는 누설자속이 발생한다. 이러한 누설자속의 수직성분에 의하여 자기광학소자의 자구는 자화되어, 공극의 중심과 자벽은 평행하게 된다. 한편, 2차 코일에 의하여 자기광학소자에 수직한 방향으로 자장을 인가하면, 누설자속분포는 공극의 중심을 기준으로 좌우 대칭이었던 자구의 분포에 편향이 발생한다. 이때 금속, 기체 또는 액체상태의 전류가 코어를 통과하면 자기광학소자의 자벽이 이동하게 된다. 이러한 원리에 의하여 자구 또는 자벽의 이동량을 측정하면, 코어를 통과하는 직류전류의 세기를 알 수 있다.

The Effect of Slider Surface Texture on Flyability and Lubricant Migration under Near Contact Conditions

  • Zhou, L.;Kato, K.;Vurens, G.;Talke, F.E.
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.277-278
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    • 2002
  • Magnetron and Ion beam sputtering were used to texture the air-bearing surface of magnetic recording sliders. Flying height measurements and Laser-Doppler interferometry were used to compare the 'flyability' of textured and untextured sliders. Lubricant redistribution on the disk surface caused by slider/disk interactions was investigated using scanning ellipsometry (Surface Reflectance Analyzer (SRA)). The results show that slider surface texture causes only small changes in the flying height of sliders but reduces slider in-plane and out-of-plane vibrations. Textured sliders were found to cause less lubricant depletion on the disk surface than untextured sliders.

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원격작업의 효율성 향상을 위한 단일 홀센서 비접촉식 전자 조이스틱 (Non-contact Electronic Joystick with a Hall Sensor for Effective Tele-operation)

  • 김홍철;강대훈;이장명
    • 제어로봇시스템학회논문지
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    • 제12권4호
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    • pp.358-363
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    • 2006
  • This paper demonstrates a new non-contact electronic joystick using single hall sensor which detects a horizontal vector of the magnetic field. Furthermore, in this paper, it is mathematically modeled that nonlinear characteristics between the output of hall sensor and the movement of joystick bar. The dynamic horizontal vector of magnetic flux is detected by the hall sensor while a permanent magnet is rotated with the joystick bar, which has two dimension detecting area. Using the nonlinear adjustment equations, the output signals of hall sensor have been linearized to give higher accuracy in the two dimension movement. Finally, through the real experiments, it is showed that the single hall sensor structure mechanism is superior to the dual sensor structure in sensing the two-dimensional motion without offset.

Hall Probe를 이용한 초전도선재의 비접촉 임계전류 측정 방법 (Non-contact critical current measurement of superconducting coated conductor using Hall Probe)

  • 김호섭;오상수;이남진;하동우;백승규;고락길;하홍수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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    • pp.12-12
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    • 2010
  • The hall probe measurement system was used to measure the critical current distribution of superconducting coated conductor. The system consists of reel to reel moving apparatus, 7 array hall probe, a rotary encoder and permanent magnet. The magnetic field profile across the width of superconducting coated conductor using Bean's critical state model was calculated. The effect of various parameters of the formulas on the magnetic field distribution and the effect of shape and size of artificial defects, which were formed on the surface of SmBa2Cu3O7-d(SmBCO) coated conductor using laser marking system, on the hall probe magnetic field signal of the hall probe measurement system was investigated.

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배선용차단기의 구동자계 증가를 위한 자성체 구조물의 와전류 해석 (Eddy Current Analysis of Magnetic Plate to Increase Magnetic Force in MCCB)

  • 이세연;백명기;이보람;김영선;박일한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.909-910
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    • 2007
  • To design the Molded Case Circuit Breaker(MCCB) requires electromagnetic analysis in contact system when the circuit breakers interrupt fault currents. This paper has made sure that there are two ways increasing arc driving force, one is a change of contact point and the other way inserts additionally the magnetic plate. Finally, we have carried out the analysis of eddy current to identify a decrease of arc driving force because of fault currents. In this paper, MCCB models have been analyzed base on 3D-FEM by Maxwell program.

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STATE OF ART OF SELFBEARING MOTOR

  • Okada, Yohji;Ueno, Satoshi;Ohishi, Tetsuo
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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    • pp.20-25
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    • 1997
  • Magnetic bearings have been widely used to support rotors without any physical contact. This however, requires the control of five degrees-of-freedom and needs a separate driving motor. This paper introduces selfbearing motors which use the combination of a rotary motor and a magnetic bearing. These motors are suitable for use in high speed rotor or in special circumstances because they are small in size and can replace the contact components. The radial type one has the merit of being small in size and capable of controlling two degrees-of-freedom in x and y directions. The axial type motor controls only one degree-of-freedom in z direction. Theoretical background of the functions, of the motor and magnetic bearing will also be introduced. New research works are reviewed and the application in rotary blood pump is discussed.

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SLIDERS FOR THE NEXT GENERATION MAGNETIC HARD DISK DRIVE SYSTEMS-NUMERICAL SIMULATION

  • Jhon, Myung-S.;Peck, Paul-R.;Kang, Soo-Choon;Wang, Benjamin-L.;Kim, In-Eung;Park, Ki-Ook
    • 한국자기학회지
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    • 제5권5호
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    • pp.695-701
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    • 1995
  • Fundamental issues and general procedures of modeling the head disk interface (HDI) in order to provide design criteria for future ultra-low flying sliders are given. Intermittent contact and gaseous rarefaction effects are discussed using nonconventional kinetic theory. To illustrate the simulation results, we modeled IBM 3370 taper flat sliders and positive/negative "bow tie" sliders. Several alternative HDI concepts for future disk drives - viscoelastic bearings, a hybrid system, and contact recording - are also briefly discussed.

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Advanced techniques of solution nuclear magnetic resonance spectroscopy for structural investigation of protein-protein interaction

  • Sugiki, Toshihiko;Lee, Young-Ho
    • 한국자기공명학회논문지
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    • 제22권4호
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    • pp.76-81
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    • 2018
  • Investigation of the protein-protein interaction mode at atomic resolution is essential for understanding on the underlying functional mechanisms of proteins as well as for discovering druggable compounds blocking deleteriou interprotein interactions. Solution NMR spectroscopy provides accurate and precise information on intermolecular interactions even for weak and transient interactions, and it is also markedly useful for examining the change in the conformation and dynamics of target proteins upon binding events. In this mini-review, we comprehensively describe three unique and powerful methods of solution NMR spectroscopy, paramagnetic relaxation enhancement (PRE), pseudo-contact shift (PCS), and residual dipolar coupling (RDC), for the study on protein-protein interactions.

Estimation of Output Voltage and Magnetic Flux Density for a Wireless Charging System with Different Magnetic Core Properties

  • Park, Ji Hea;Kim, Sang Woo
    • Journal of Magnetics
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    • 제18권2호
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    • pp.105-110
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    • 2013
  • The design model and key parameters of the material design for the control of induced magnetic flux at the near-field and efficient power transfer in a modified wireless power transfer (WPT) system with a large air gap of wireless electric vehicles were investigated through analytical simulations for magnetic vector and time-domain transient analysis. Higher saturation magnetic core with low core loss induced a stronger vertical magnetic field by the W-type primary coil in the WPT system with a gap of 20 cm at 20 kHz, which is shown from the vector potentials of the magnetic induction. The transient analysis shows that the higher magnetic fluxes through the pick-up cores lead to a linear increment of the alternating voltage with a sinusoidal waveform in the non-contact energy transfer system.