• Title/Summary/Keyword: Electromagnetic Resistance

Search Result 263, Processing Time 0.027 seconds

The Physical Properties and Shielding Efficiency of Electromagnetic Wave Shielding Cement Mortar Using Magnetite-Carbon (Magnetite-Carbon을 이용한 전자파 흡수형 차폐 시멘트 모르터의 물리적 특성과 차폐효율)

  • Park Dong Cheol;Lee Sea Hyun;Song Tae Hyup;Shin Jong Woo
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2004.05a
    • /
    • pp.608-611
    • /
    • 2004
  • As the use of various electronic equipments has been increased recently according to industrialization and information network establishment, concern about electromagnetic wave exposed environment has also been increased. Therefore, this study aims to verify electromagnetic wave absorbing effects of inorganic paint that is made of carbon, electro-conductive materials with regard to its physical characteristics, its electromagnetic wave absorbing rate through a mock-up test for proving its effects in the indoor condition. The results are as follows: The results of running tests on electromagnetic wave absorbing inorganic paints for checking their requirements as painting material such as adherence degree, resistance to fine crack, resistance to washing, alkali-resistance, discoloration-resistance, etc. show that inorganic paints have the physical characteristics meeting the requirements for painting materials. In addition, it shows that the electromagnetic wave absorbing effect, in line with the number of paintings and the thickness of paintings, secures $75\~89\%$ of efficiency. And the mock-up test shows that the electromagnetic wave absorbing effect inside building is directly proportional to the distance from the source of electromagnetic wave such as electronic equipments.

  • PDF

An Analytical Approach to the Spark Resistance Formula Caused by Electrostatic Discharge

  • Kang, In-Ho;Kim, Dong-Il
    • Journal of the Korean Institute of Navigation
    • /
    • v.21 no.2
    • /
    • pp.69-75
    • /
    • 1997
  • A modern electric system located at a certain distance from the discharge may respond with unexpected sensitivity, when an electrostatic discharge (ESD) phenomenon occurs heteronomously between metallic objects. For analyzing the transient electromagnetic fields caused by ESD, two resistance formulas - Toepler and Rompe-Weizel -are introduced. The experimental result given by Wilson-Ma are used to compare which of these resistance formulas is proper.

  • PDF

Resistive Grounding Technique of Heat Sink for Reducing Radiation Noise

  • Ahn, Chang-Hoi;Oh, JaeHyun
    • Journal of Electrical Engineering and Technology
    • /
    • v.9 no.5
    • /
    • pp.1724-1728
    • /
    • 2014
  • Heat sink has been used to help an electrical device operate in normal temperature condition. But heat sink radiates unwanted electromagnetic wave, which may cause electromagnetic interference problem. A resistance loaded grounding technique is proposed to reduce electromagnetic wave radiation by a heat sink. Numerical simulations are accomplished to find optimal loading resistance. Also electromagnetic fields radiated by from a heat sink are measured and compared with the simulation results. The test results verify the usefulness of the proposed technique.

A Study on the Electromagnetic shielding Effectiveness Using Conductive Polymers (전도성 고분자를 이용한 전자파 차폐효과의 연구)

  • 하남규;이보현;김태영;김종은;서광석
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.3
    • /
    • pp.207-214
    • /
    • 2001
  • The conductive polymers, polyaniline (PANI) emeralidin base and 3,4-polyethylene dioxythiophene(PEDOT) were synthesized and coated on the PET film dealt with acryl type primer to study the electromagnetic shielding effectiveness. When both PANI and PEDOT were coated on the PET film dealt with acryl type priemer, their surface properties such as he adhesive increased. For PANI, when blended with the binder such as PMMA, it adhesive and surface hardness increased, too. The visible light transmittance decreased, while the electromagnetic shielding effectiveness increased, when coated thickness of PANI and PEDOT increased. For PANI, the electromagnetic shielding effectiveness increased as its surface resistance decreased. For PANI, when the surface resistance was 140 Ω/$\square$, the shielding effectiveness was found to be 11 dB in the far field, and 13 dB in the near field at 1 GHz. For PEDOT, when the surface resistance was 200 Ω/$\square$, the shielding effectiveness was found to be 3 dB in the far field, and 7dB in the near field.

  • PDF

The Electromagnetic Shielding Effectiveness Using Conducting Polymers (전도성 고분자를 이용한 전자파 차폐효과)

  • 하남규;김종은;서광석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.11a
    • /
    • pp.306-309
    • /
    • 2000
  • The conductive polymers, polyaniline (PANI) emeraldine base and 3, 4-polyethylene dioxythiophene (PEDOT) were synthesized and coated on the PET film primer-dealt with acryl type to find out the electromagnetic shielding effectiveness. When conductive polymer such as PANI and PEDOT is used, if the thickness of coating increases then the electromagnetic shielding effectiveness increases, too, but the visible light transmittance decreases. For PANI, when its conductivity increased, its electromagnetic shielding effectiveness increased, too. For PANI, if the surface resistance is about 140 $\Omega$/$\square$, the shielding effectiveness is about 11 dB in the far field, and about 13 dB in the near field at 1 GHz. For PEDOT, when the surface resistance is about 200 $\Omega$/$\square$, the shielding effectiveness is about 3 dB.

  • PDF

A Study on Malfunction Mode of CMOS IC Under Narrow-Band High-Power Electromagnetic Wave (협대역 고출력 전자기파로 인한 CMOS IC에서의 오동작 특성 연구)

  • Park, Jin-Wook;Huh, Chang-Su;Seo, Chang-Su;Lee, Sung-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.29 no.9
    • /
    • pp.559-564
    • /
    • 2016
  • This study examined the malfunction mode of the HCMOS IC under narrow-band high-power electromagnetic wave. Magnetron is used to a narrow-band electromagnetic source. MFR (malfunction failure rate) was measured to investigate the HCMOS IC. In addition, we measured the resistance between specific pins of ICs, which are exposed and not exposed to the electromagnetic wave, respectively. As a test result of measurement, malfunction mode is shown in three steps. Flicker mode causing a flicker in LED connected to output pin of IC is dominant in more than 7.96 kV/m electric field. Self-reset mode causing a voltage drop to the input and output of IC during electromagnetic wave radiation is dominant in more than 9.1 kV/m electric field. Power-reset mode making a IC remained malfunction after electromagnetic radiation is dominant in more than 20.89 kV/m. As a measurement result of pin-to-pin resistance of IC, the differences between IC exposed to electromagnetic wave and normal IC were minor. However, the five in two hundred IC show a relatively low resistance. This is considered to be the result of the breakdown of pn junction when latch-up in CMOS occurred. Based on the results, the susceptibility of HCMOS IC can be applied to a basic database to IC protection and impact analysis of narrow-band high-power electromagnetic waves.

An Active Bandpass Filter Using Negative Resistance Circiuts (부성저항을 이용한 능동 대역 통과 여파기)

  • 신상문;권태운;최재하
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2000.11a
    • /
    • pp.229-232
    • /
    • 2000
  • In this study, An active band grass filter for 2.14GHz have been designed with MMIC using negative resistance circuit. The negative resistance element was realized with a common-drain FET with series inductive feedback. The designed active filter showed an insertion loss of 0dB at 2.14GHz and a 3-dB bandwidth of 125MHz.

  • PDF

Electromagnetic Environment of Transmission Line Based on Full Parameter Online Estimation

  • Sun, Zidan;Zhou, Xiaofeng;Liang, Likai;Mo, Yang
    • Journal of Information Processing Systems
    • /
    • v.16 no.2
    • /
    • pp.394-405
    • /
    • 2020
  • The parameters of transmission lines have an influence on the electromagnetic environment surrounding the line. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and data acquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance, reactance and susceptance. The proposed full parameter estimation method is compared with the traditional method of estimating resistance independently based on SCADA system. Then, the electromagnetic environment is analyzed based on the different parameter estimation methods. The example results illustrate that online estimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment, which further confirms its necessity and significance in engineering application.

On the Flow and Pumping Characteristics of a Thermopneumatic Micropump with Electromagnetic Resistance for Electrically Conducting Fluids (전자기 저항을 이용한 열공압형 마이크로 펌프에서 통전유체의 유동 및 펌핑 특성에 관한 연구)

  • Oh, Se-Hong;Yong, Jung-Kwon;Kim, Chang-Nyung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.23 no.1
    • /
    • pp.23-31
    • /
    • 2011
  • An analysis has been conducted of the flow characteristics and pumping performance of a thermopneumatic micropump with electrically conducting fluid. In the present study, considered is a thermopneumatic micropump for electrically conducting fluids with electromagnetic resistance alternately exerted at the inlet and outlet by alternately applied magnetic fields. A model of Prescribed Deformation is used for the motion of the membrane. Here, the pumping performance of the micropump and flow characteristics of the electrically conducting fluid are investigated in the range of Hartmann number less than 30. The current numerical study shows that the net flow rate through the micropump is almost proportional to the strength of the applied magnetic field.