• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.251-255
• /
• 2003

In this paper, we have a fluxgate sensor with ferrite core. Thought sensor is consist of one excitation coil and two pick-up coil, and A lock-in amplifier circuity is designed for Signal processing of picking up 2nd harmonics from pick-up coils. Excitation coils is turned by 20 turns, and pick-up coil for picking up harmonics is turned by 40 turns eachother. It convert 2nd harmonics to DC output voltage. Measured output voltage and sensitivity, direction of sensor about out side magnetic field, and also sensor output properties about excitation frequency and current.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1442-1443
• /
• 2006

본 논문에서는 분말 연자성체에 플라즈마를 이용하였을 때 특성 개선에 관한 연구이다. 기존의 압분 방식은 낮은 강도를 갖는 단점 때문에 신뢰성에 문제가 있어서, 직접적인 모터분야에 연자성체(SMC)를 적용하는데 큰 문제점 이였다. 그러나 본 논문에서 제안하는 SPS(Spark Plasma sintering)공법을 적용한 모터 코어 제조 방법은 플라즈마를 이용하여 분말의 표면에서만 접촉이 일어나게 하는 소결 방식으로, 내부재질의 특성변화 없이 표면의 절연층끼리만 접촉되게 하여 자기적 특성의 손상없이 기계적인 강도를 높일 수 있었다. 실제적으로 기존의 압분체(Hoganass550+윤활제(KE))의 경우 파단강도가 700Mpa정도였으나 SPS를 적용시 1200Mpa까지 증가 되었다. 이러한 SPS 공법을 통해 연자성체(SMC)재질의 모터 Core 분야 적용하는 데 생기는 문제점을 해결하고자 하였다.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.843-845
• /
• 2003

In this paper, the design of the outer core which is one part of the linear motor is investigated by using the topology optimization and FEM. The object functions are to reduce the outer core area of the linear motor with the maximum magnetic energy in airgap. For topology optimization, the finite element model is made through the result of ANSYS, and the sensitivity calculation is done using ANSTOP(developed general software for topology optimization of electromagnetics). In ANSTOP, the optimization routine is implemented using SLP in DOT and the ANSYS is used as a function solver.

• Journal of Sensor Science and Technology
• /
• v.18 no.5
• /
• pp.393-401
• /
• 2009

This paper describes development of a new displacement sensor for intelligent suspension system in which the damping force has been controlled by MR fluid. Most of the current vehicle height sensors have been installed at external place of the damper and connected to that by mechanical linkages so far. The developed sensor has a new mechanism which detects movement of the sensor rod same as connecting rod in the suspension damper by using a GMR Sensor and converts it to the relative displacement from an initial position.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.81-82
• /
• 2012

A novel kind of switched reluctance motor (SRM) with short flux path is proposed in this paper. Phase excitation in the SRM gives short flux paths, hence reducing the magnetomotive force required to drive the machine, resulting in significant reduction of copper wire and core losses compared to the typical SRM with diametric circulation of magnetic flux. To verify the performance, the characteristics analysis of a double stator SRM, a 6/5 SRM with C-core structure and a 4/5 two-phase SRM which all composed of short flux path and a comparison with conventional SR motors are executed.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.78-80
• /
• 2001

This paper deals with a comparison between the secondary Halbach array and conventional array of permanent magnets(PMs) in air-core type linear synchronous motor(LSM). Two types of PMLSM are analyzed and compared, with reference to the following parameters as variables: magnetic field, thrust and back emf.

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.67-69
• /
• 1998

The cogging torque in the small BLDC motors used in the DVD driving system or HDD driving system can cause some serious vibration problem. In this paper, some core shapes that reduce cogging torque are found by using reluctance network method(RNM) for magnetic field analysis and genetic algorithm(GA) for optimization. The outer rotor type BLDC motor for the DVD ROM driving system has been optimized as an sample model.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2008.12a
• /
• pp.139.1-139.1
• /
• 2008

• Nuclear Engineering and Technology
• /
• v.54 no.2
• /
• pp.565-578
• /
• 2022

Among Generation IV reactors, the sodium-cooled fast reactor (SFR) is attracting attention as a system having great potential for commercial use. Gas entrainment is a thermal-hydraulic issue related to the safety problem of the reactor core in the SFR. Typically, a dipped plate or baffles are installed under the free surface to suppress gas entrainment. However, these approaches can cause gas entrainment in other locations and require many trial-and-error and verifications. In this study, a new strategy using magnetohydrodynamics to suppress gas entrainment in the SFR is proposed. In a counter-flow model, a judgment criterion of gas entrainment occurrence was developed for both water and liquid metal. Moreover, the gas entrainment can be completely suppressed by applying a magnetic field.

• Current Optics and Photonics
• /
• v.7 no.1
• /
• pp.83-89
• /
• 2023

This study reports a structure, based on a liquid-crystal (LC) core optical waveguide, for the switchable spatial control of linearly polarized light. The refractive indices of both left and right isotropic claddings in the waveguide are between the two principal-axis indices of the nematic liquid crystal (NLC). Numerical simulations demonstrate that the proposed structure can be operated in transmission mode or as an attenuator by controlling the on and off states of the applied voltage, whether the initial excitation is transverse electric (TE) linearly polarized light or transverse magnetic (TM) linearly polarized light. The design can also be used as an integrated optical polarizer, since only one type of linearly polarized light is always permitted to pass through the core zone of the NLC optical waveguide.