• Title/Summary/Keyword: Solenoid Core

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Magnetic Circuit Design Methodology of MR CDC Dampers for Semi-Active Suspensions (반능동 서스펜션용 MR CDC 댐퍼의 자기회로 설계기법)

  • Park, Jae-Woo;Jung, Young-Dae
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.10
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    • pp.48-57
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    • 2008
  • MR Fluid, one of functional fluids, is developed for the application to automobile products. MR CDC damper using MR fluid has following principles. When ar electric current is applied to the solenoid, apparent viscosity of MR fluid passing through the annular gap which acts as magnetic circuits varies directly as the intensity of the current. These devices have a simple structure and excellent lime response characteristics, emerging as the alternatives of the conventional semi-active suspension systems. In this study, a design procedure of the magnetic circuit through the solenoid fore and the flux ring functioning as a magnetic path is investigated so as to optimize the design and performance of MR CDC dampers for the vehicles. In addition, an operating point on the B-H curve, the magnetization according to the variation in the annular gap, the pole piece width and the density of MR fluid are studied to design the optimal piston head within the restrained dimension range.

Iron Core Design of 3-Phase 40MVA HTS Power Transformer Considering Voltages per Turn

  • Lee, Chan-joo;Seok, Bok-yeol
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.4B no.2
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    • pp.54-58
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    • 2004
  • This paper presents the iron core design method of a high temperature superconducting (HTS) transformer considering voltages per turn (V/T). In this research, solenoid type HTS coils were selected for low voltage (LV) winding and double pancake coils for high voltage (HV) winding, just as in conventional large power transformers. V/T is one of the most fundamental elements used in designing transformers, as it decides the core cross sectional area and the number of primary and secondary winding turns. By controlling the V/T, the core dimension and core loss can be changed diversely. The leakage flux is another serious consideration in core design. The magnetic field perpendicular to the HTS wire causes its critical current to fall rapidly as the magnitude of the field increases slowly. Therefore in the design of iron core as well as superconducting windings, contemplation of leakage flux should be preceded. In this paper, the relationship between the V/T and core loss was observed and also, through computational calculations, the leakage magnetic fields perpendicular to the windings were found and their critical current decrement effects were considered in relation to the core design. The % impedance was calculated by way of the numerical method. Finally, various models were suggested.

Developing Analysis Model of Hydraulic System for Dental Chair (치과용 유니트체어 유압구동 시스템 해석모델 개발)

  • Dae Kyung Noh;Dong Won Lee;Taek June Kim;Joo Sup Jang
    • Journal of Drive and Control
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    • v.20 no.1
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    • pp.27-33
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    • 2023
  • From the perspective of dental chair manufacturers, it is important to of localizing hydraulic system in order to secure market competitiveness. This study aims to develop the analysis model of a dental chair which overseas companies secure core technologies. The study follows the steps below. First, the component parts of the solenoid valve unit of a foreign leading company are analyzed and implemented in virtual environment. Second, dynamic behavior scenario is established based on solenoid valve signal chart provided by a foreign leading company. The analysis model is verified and its performance is analyzed using dynamic behavior according to each scenario. Third, a simulation is carried out to determine whether the cylinder velocity of designed hydraulic system surpasses 1cm/s as required by the design.

Frequency Characteristics for Micro-scale SMD RE Chip Inductors of Solenoid-Type (Solenoid 형태의 초소형 SMD RF 칩 인덕터에 대한 주파수 특성)

  • Kim, Jae-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.3
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    • pp.454-459
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    • 2007
  • In this work, micro-scale, high-performance solenoid-type RF chip inductors utilizing amorphous $Al_2O_3$ core material were investigated. The size of the chip inductors was $0.86{\times}0.46{\times}0.45mm^3$ and copper(Cu) wire with $27{\mu}m$ diameter was used as the coil. High frequency characteristics of the inductance(L), quality factor(Q), impedance(Z), and equivalent circuit parameters of the RE chip inductors were measured and analyzed using an RF impedance/material analyzer(HP4291B with HP16193A test fixture). It was observed that the RF chip inductors with the number of turns of 9 to 12 have the inductance of 21 to 34nH and exhibit the self-resonant frequency(SRF) of 5.7 to 3.7GHz. The SRF of inductors decreases with increasing the inductance and inductors have the quality factor of 38 to 49 in the frequency range of 900MHz to 1,7GHz.

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Magnetic Field annealing apparatus for Clamped Amorphous Transformer Core (주상 변압기용 비정질 코어의 자장인가 코일 제작)

  • Song, Jae-Sung;Jeong, Soon-Jong;Kim, Ki-Uk;Kim, Byung-Geol;Hwang, See-Dole;Jeong, Young-Ho
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.193-195
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    • 1996
  • In amorphous transformer core, magnetic field annealing is required for inducing uniaxial magnetic anisotropy to circular direction of the core. Generally annealing temperature is about foot, so insulator using in solenoid bed must have a high temperature stability, mechanical strength and good machinability. In this study, we made the magnetic field annealing apparatus using insulators, conductors, connectors and power supply. And then tested the apparatus in annealing process of 50 kVA amorphous transformers.

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High Sensitivity Micro-fabricated Fluxgate Sensor with a Racetrack Shaped Magnetic Core

  • Choi, Won-Youl;Kim, So-Jung
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.3
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    • pp.110-114
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    • 2005
  • We present a micro fluxgate magnetic sensor having solenoid coils and racetrack shaped magnetic core, which was designed to decrease the .operating power and magnetic flux leakage. Electroplated copper coils of $6\;{\mu}m$ thickness and the core of $3\;{\mu}m$ thickness were separated by benzocyclobutane (BCB) having a high insulation and good planarization characters. Permalloy $(Ni_{0.8}Fe_{0.2})$ as a magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The core had the high DC effective permeability of $\~1,300$ and coercive field of $\~0.1$ Oe. The fabricated fluxgate sensor had the very small actual size of $3.0\times1.7\;mm^2$. The fluxgate sensor with a racetrack shaped core had the high sensitivity .of $\~350$ V/T at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.

Development of Electronic Compass Using 2-Axis Micro Fluxgate Sensor (2축 마이크로 플럭스게이트 센서 제작을 통한 전자 나침반 개발)

  • 박해석;심동식;나경원;황준식;최상언
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.9
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    • pp.418-423
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    • 2003
  • This paper describes an electronic compass using micromachined X- and Y-axis micro fluxgate sensors which were perpendicularly aligned each other to measure X- and Y-axis magnetic fields respectively. The fluxgate sensor was composed of rectangular-ring shaped magnetic core and solenoid excitation(49 turns) and pick-up(46 turns) coils. Excitation and pick-up coil patterns which were formed opposite to each other wound the magnetic core alternatively to improve the sensitivity and to excite the magnetic core in an optimal condition with reduced excitation current. The magnetic core has DC effective permeability of ~1000 and coercive field of ~0.1 Oe. The magnetic core is easily saturated due to the low coercive field and closed magnetic path for the excitation field. To decrease the difference of induced second harmonic voltages from X- and Y-axis, excitation condition of 2.8 $V_{P-P}$ and 1.2 MHz square wave was selected. Excellent linear response over the range of -100 $\mu$T to +100 $\mu$T was obtained with 210 V/T sensitivity. The size of each micro fluxgate sensor excluding pad region was about 2.6${\times}$1.7 $mm^2$ and the power consumption was estimated to be 14 mW.W.

A MICRO FLUXGATE SENSOR IN PRINTED CIRCUIT BOARD (PCB) (인쇄회로 기판에 내장된 마이크로 플럭스게이트 센서)

  • 최원열;황준식;나경원;강명삼;최상언
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.151-155
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    • 2002
  • This paper presents a micro fluxgate magnetic sensor in printed circuit board (PCB). The fluxgate sensor consists of five PCB stack layers including one layer magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core is made of a micro patterned amorphous magnetic ribbon with extremely high DC permeability of ∼100,000 and the core has a rectangular-ring shape. The amorphous magnetic core is easily saturated due to the low coercive field and closed magnetic path for the excitation field. Four outer layers as an excitation and pick-up coils have a planar solenoid structure. The chip size of the fabricated sensing element is 7.3${\times}$5.7m㎡. Excellent linear response over the range of -100${\mu}$T to +100${\mu}$T is obtained with 540V/T sensitivity at excitation square wave of 3V$\_$P-P/ and 360kHz. The very low power consumption of ∼8mW was measured. This magnetic sensing element which measures the lower fields than 50${\mu}$T, is very useful for various applications such as: portable navigation systems, military research, medical research, and space research.

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Embedded Micro Fluxgate Sensor in Printed Circuit Board (PCB) (PCB 기판에 내장된 마이크로 플럭스게이트 센서)

  • 최원열;황준식;강명삼;최상언
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.8
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    • pp.702-707
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    • 2002
  • This paper presents a micro fluxgate sensor in printed circuit board (PCB). The fluxgate sensor consists of five PCB stack layers including one layer magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core is made of a micro patterned amorphous magnetic ribbon and the core has a rectangular-ring shape. The amorphous magnetic core is easily saturated due to the low coercive field and closed magnetic path for the excitation field. Four outer layers as an excitation and pick-up coils have a planar solenoid structure. The chip size of the fabricated sensing element is 7.3$\times$5.7$\textrm{mm}^2$. Excellent linear response over the range of -100$\mu$T to +100$\mu$T is obtained with 540V/T sensitivity at excitation square wave of 3 $V_{p-p}$ and 360kHz. The very low power consumption of ~8mW was measured. This magnetic sensing element, which measures the lower fields than 50$\mu$T, is very useful for various applications such as: portable navigation systems, military research, medical research, and space research.h.