• Title/Summary/Keyword: Magnetic shields

Search Result 16, Processing Time 0.02 seconds

A study on the electrostatic and magnetic flux cut off effect using anti-magnetic material (반자성 물질에 의한 전자기차단효과에 관한 연구)

  • Hwang, Yoon-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.12 no.8
    • /
    • pp.1473-1480
    • /
    • 2008
  • Bisumus has a low melting point, making it easier to handle. This allows us to test what type of effect diamagnetism has on electro static and magnetic field shields. However, the actual materials for experimentation have only ever been manufactured cylindrically, and so there have been no recorded cases of measurements to this effect. To understand what kind of effect pure bisumus as diamagnetism has on electro static and magnetic shields in comparison to other materials, bisumus, along with copper, aluminum and iron 스텐도, were used to make a cylinder each. These cylinders were then used to measure and compare the electro static shield and magnetic shield at different bands of frequencies, starting from a low frequency. As shown on the graph/chart/diagram, the best results were recorded for copper and bisumus as diamagnetism in an electro static field. In terms of magnetic shielding, iron provided the best results, as expected, whereas bisumus displayed minimal effect.

Magnetic-Shielding Effectiveness Analysis of the Trigger Assembly of Small Arms (소구경 개인화기 격발신호 발생장치의 자기차폐효과 분석)

  • Lee, Kisu;Ahn, Joon Mo;Chae, Je-Wook
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.4
    • /
    • pp.456-463
    • /
    • 2018
  • With the development of weapon systems by mounting various sensors, it makes important to analyze the precise functioning of sensor to external environment. In the case of small arms with magnetic sensor, the malfunction of small arms might be caused by strong external magnetic fields. In this study, the effects of magnetic sensor on external magnetic fields were analyzed, and optimal magnetic shield and shield structure were designed through M&S. In addition, the magnetic-shielding effectiveness of magnetic sensor in small arms was verified with commercial shielding materials. As a result, it was demonstrated that the Fe-Cu-Si-Nd-B with the structure of multi-layer metallic shields was shown the magnetic-shielding effectiveness of 83 % for an external permanent magnet and 19 % for an alternating magnetic field of 180 dBpT at 60 Hz, respectively.

A New Concept of Magnetic Cable for Safe Mobile Power Delivery (안전한 전력전달을 위한 새로운 형태의 자기케이블)

  • Lee, Woo-Young;Huh, Jin;Choi, Su-Yong;Rim, Chun-Taek
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.16 no.6
    • /
    • pp.542-553
    • /
    • 2011
  • A magnetic cable that can safely deliver high frequency AC electric power in flammable or sensitive workplaces by preventing from arcs and electric shocks is firstly proposed in this paper. Several new magnetic cable structures with magnetic shields, which are composed of such cancel coil, cancel copper plate, and cancel copper pipe, were compactly implemented by considering and analyzing fringe field and thus the parallel leakage flux is drastically reduced. The output power and efficiency of a prototype magnetic cable with 1.5 m length and 5 cm gap were measured as 353.8W and 68%, where the source current and switching frequency were 10 $A_{rms}$ and 20 kHz, respectively. The proposed magnetic cables are fully analyzed and verified by finite-element method (FEM) simulations and experiments. The results are in a good agreement.

OBSERVATION OF THE DOMAIN STRUCTURES IN SOFT MAGNETIC ${(Fe_{97}Al_3)}_{85}N_{15}/Al_2O_3$ MULTILAYERS

  • Stobiecki, T.;Zoladz, M.;Roell, K.;Maass, W.
    • Proceedings of the Korean Magnestics Society Conference
    • /
    • 2002.12a
    • /
    • pp.14-15
    • /
    • 2002
  • Iron nitride alloy films prepared in the form of laminated ${(Fe_{97}Al_3)}_{85}N_{15}/Al_2O_3$ multilayers (Ml's) due to excellent soft magnetic properties and high saturation magnetization [1, 2] are very promising materials for poles and shields in ultra high density thin film heads. The present work concerns the ferromagnetic (FM) coupling effect as a function of the thickness of $Al_2O_3$ spacers by analysis of the magnetic domain structure.

  • PDF

Analysis of Shielding Effectiveness and Estimation of Shielding Factor in Conductive and Magnetic Shields (도전성 및 자성 차폐체의 차폐효과 해석과 차폐인수 산정)

  • Kang, Dae-Ha
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.10
    • /
    • pp.30-40
    • /
    • 2013
  • In this study the method based on flux linkage in cell was introduced in calculation of eddy currents by cell method. According to this method eddy current distribution and the loss can be evaluated and since the shielding effectiveness by flux cancelation of eddy current can be analyzed, this method is applicable to design of conductive shield. And also the formula of shielding factor were so deduced as to be applicable to finite-width infinite-length shielding sheets and infinite-length underground cable shield. These formula are adaptable to magnetic materials as well as conductive materials. As the results of calculation in model shields are follows. In case of finite-width infinite-length shielding sheet, shielding effectiveness increases with increasing of conductivity. In case of infinite-length underground cable shield, the effectiveness become higher with increasing of permeability. Especially the effectiveness is very high in materials with both high conductivity and permeability in underground cable shield.

Finite Element Analysis of the Transient Characteristics of a Superconducting A.C. Generator (유한요소법에 의한 초전도교류 발전기의 과도 특성 해석)

  • 한성진;배동진
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.40 no.1
    • /
    • pp.24-30
    • /
    • 1991
  • This paper deals with the analysis of the transient characteristics of a superconducting a.c. generator(SCG) using Finite Element Method. Since the magnetic field induced by the field current and the armature currents are not sinusoidally distributed in a generator, the conventional equivalent circuit method, in general, uses the fundamental component only and is done in frequency domain. But the finite element analysis makes it possible to analyze the transient magnetic field distribution and the electrical characteristics of the double shields of SCG in time domain.

  • PDF

Reduction of thickness of steel strip applied for Inner Magnetic Shields (of CRT) manufacturing from 0,15mm to 0,1mm.

  • Leonov, Evgeny A.;Zubov, Valery I.;Uvarov, Boris N.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.1072-1073
    • /
    • 2002
  • We report using thin steel strip (0,1mm) for manufacturing Inner Magnetic Shield of CRT. Here we report that the reducing of steel strip thickness from 0,15mm to 0,1mm is possible as for one-piece IMS and for two-piece IMS without any reflection on quality of CRT. Also we report about advantages, which the producer of CRT could reach using steel with lowed carbon content up to 0,0005% by mass.

  • PDF

Magnetic Shielding Characteristics of the Slitted Electrothermal Shield (틈새를 낸 열전자 차폐막의 자기차폐특성)

  • 이홍배;배동진;김석환;원영진;한성진;차귀수;한송엽
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.40 no.6
    • /
    • pp.562-566
    • /
    • 1991
  • Many research and development activities have found that Superconducting Generators (SCG) have advantages such as high efficiency, light weight, small size, large unit size and good steady-state stability over conventional ones. However the transient stability of SCG is comparable to that of conventional ones. One way to improve the transient stability of SCG is to apply quick-response excitation system to the SCG. For this purpose, an SCG with an electrothermal shield of short electric time constants should be developed. In this paper, a new electrothermal shield, called slitted electrothermal shield(SES), is proposed. The SES can easily transmit radiated heat into the ends of the shield as in the conventional electrothermal shields(CES) and can easily pass magnetic flux produced by armature and field windings. By finite element analysis and experimental test, the slitting effects of SES on magnetic shielding are compared. Good agreement is obtained between simulated and test results.

  • PDF

Magnetic Shielding Effects of the Electrothermal Shield of a Superconducting Generator with Quick-Response Excitation (속응 여자식 초전도 발전기 열전자 차폐막의 전자 차폐 특성 해석)

  • Lee, H.B.;Bae, D.J.;Kim, S.Wh;Hahn, S.C.;Cha, G.S.;Hahn, S.Y.
    • Proceedings of the KIEE Conference
    • /
    • 1990.11a
    • /
    • pp.49-52
    • /
    • 1990
  • In this paper, we proposed a new electrothermal shield model with slits for the purpose of applying to the Superconducting Generator with Quick-Response Excitation. Via experimental and finite element analysis, we compared the magnetic shielding effects of the proposed electrothermal shield model with the conventional one. It is considered that he proposed models meet the needs for the electrothermal shields of the Superconducting Generator with Quick-Response Excitation.

  • PDF