• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.773-775
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• 1998

This paper describes the highly sensitive Si Hall magnetic sensing system which can measure the earth magnetic field. Generally, the important parameters in Hall device which degrade the ability of magnetic detection are offset voltage and 1/f noise. The offset voltage and 1/f noise in Hall plates can be reduced by spinning current method. In this paper, we implement the highly sensitive Si Hall magnetic sensing system using spinning current method. As a result, the minimum detectable magnetic field is 0.1G.

• Ceramist
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• v.23 no.1
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• pp.38-53
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• 2020

Magnetoelectric (ME) composites composed of magnetostrictive and piezoelectric materials derive interfacial coupling of magnetoelectric conversion between magnetic and electric properties, thus enabling to detect ultra-low magnetic field. To improve the performance of ME composite sensors, various research teams have explored adopting highly efficient magnetostrictive and piezoelectric phases, tailoring of device geometry/structure, and developing signal process technique. As a result, latest ME composites have achieved not only outstanding ME conversion coefficient but also sensing of ultra-low magnetic field below 1pT. This article reviews the recent research trend of ME composites for sensing of ultra-low magnetic field.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.94-96
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• 2009

This paper deals with the design considerations of electro-magnet (EM)-permanent magnet (PM) hybrid levitation and propulsion device for magnetically levitated (maglev) vehicles. Several design considerations such as machine structure, manufacturing, and control strategy are described. In order to verify the design scheme and feasibility of control strategy, dynamic test set is implemented and tested.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_1
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• pp.231-238
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• 2023

This paper develops the theory for a novel fault-tolerant, permanent magnet biased, 6-active-pole, homopolar magnetic bearing. The Lagrange Multiplier optimization with equality constraints is utilized to calculate the optimal distribution matrices for the failed bearing. some numerical examples of distribution matrices are provided to illustrate the new theory. Simulations show that very much the same dynamic responses (orbits or displacements) are maintained throughout failure events (up to any combination of 3 coils failed for the 6 pole magnetic bearing) while currents and fluxes change significantly. The overall load capacity of the bearing actuator is reduced as coils fail. The same magnetic forces are then preserved up to the load capacity of the failed bearing.

• Journal of Magnetics
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• v.22 no.2
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• pp.286-290
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• 2017

The effects of loss of torque on magnetic fluid seals with rotating-shafts and the general difficulty of studying magnetic fluid seals are the focus of this work. The mechanism underlying loss of torque on such seals is analyzed using theoretical methods that show that loss of torque can be affected by several factors, including the velocity of the rotating-shaft, the structure of the sealing device, the characteristics of the magnetic field, and the characteristics of the magnetic fluid. In this paper, a model of the loss of torque is established, and the results of finite element analysis and testing and simulations are analyzed. It is concluded that (i) the viscosity of the magnetic fluid increased with the intensity of the magnetic field within a certain range; (ii) when the magnetic fluid was saturated, the increase in loss of torque tended to gradually slow down; and (iii) although the axial active length of the magnetic fluid may decrease with increasing speed of the rotating-shaft, the loss of torque increased because of increasing friction.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.187-188
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.72-72
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.71.1-71.1
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• 2007

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.121-121
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• 2000

This paper presents a design of macro-micro system for high-speed mounting of micro-chips. A macro motion device is driven by DC servomotor and ball screw mechanism. To obtain fast response, a micro motion device utilizes a precision elector magnetic actuator In order to reduce peak impact force, We evaluate the design parameters that have an effect on it. And a characteristic of response is simulated using PID controller in velocity and force control.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.447-448
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• 2012

With wireless power transfer the of ECR device the designed with a high-frequency and high frequency AC power to the device that may enter the high-frequency switching inverter to be possible. In this paper, is designed to 2MHz switching frequency by using ECR device capable of 2MHz Class ${\Phi}_2$ inverter was designed as a wireless power transmission.