• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.5
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• pp.421-426
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• 2008

The magnetic bio-sensor used the PHR (planar hall resistance) effect generated by the free layer in spin-valve giant magnetoresistance structure of Ta/NiFe/CoFe/Cu/NiFe/IrMn/Ta. The PHR element with micrometer size was fabricated through the photolithograph and dry etching process. The PHR signal with magnetic field was measured under the conditions of with and without single magnetic bead. A single magnetic bead of diameter $2.8\;{\mu}m$ was successfully detected using the PHR sensor. Therefore, the high resolution PHR sensor can be applied to bio-sensor application utilizing the output voltage variation of the PHR signals in the presence and absence of a single magnetic bead.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.357-361
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• 2007

Transverse Linear Motor(TFLM) has been using in many areas of manufacture such as LCD, PDP construction and etc. However, the areas of TFLM application become wider, it needs a modification for new application. Above all, the conventional position estimation method is expensive in proportional to the length of the motor. Therefore, we need new position estimation algorithm using hall effect sensor.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.265-268
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• 2006

회전 기기에서 회전체의 편심은 언밸런스를 유발하는데 이를 보정하는 밸런싱은 회전 기기에서의 방진 및 저소음 설계에 중요한 항목일 뿐 아니라 회전기기의 안정성과 사용수명에 큰 영향을 미치기 때문에 매우 중요하다. 이러한 밸런싱 머신을 구현하기 위하여 편심을 정확히 측정하여야 하는데, 본 논문에서는 기존의 벨런싱 기기에 일반적으로 사용되고 있는 계측 원리와는 다르게 홀-이펙트 센서를 이용하여 편심을 측정하는 방식을 제안함으로써 저가의 계측 시스템 구성이 가능함을 보이고, 밸런싱 신의 편심 측정부를 PC통신을 이용하여 제어하고자 한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.4
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• pp.200-204
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• 2014

LPG is used in the home would have to depend on the provider, because there is no method for measuring the capacitance. In addition, by measuring the gas capacities can not be known because of the LPG gas replacement time and requires an alarm for replacement. In this study, and that the gas capacities to the trusted user and the supplier, in order to know when it is time to change to LPG gas by applying a Hall effect sensor developed a gas capacities measurement the valve system.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.228-234
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• 2001

NTMS(Non-contact Tilted-angle Measuring System) is developed by using the principle that the magnetic field of an anisotropic magnet's inner space is uniform and it's possible to measure the strength of the magnetic field using a linear hall effect sensor. In order to implement the caliper system of the geometry PIG(Pipeline Inspection Gauge) which has high accuracy and proper output voltage of the hall sensor without additional driving module or a signal amplifier, it is necessary to consider the size of the magnet, the inner space and back-yoke and the position of pin-hole in the magnet. So the optimal design method of the caliper system is proposed through analysis of NTMS's magnetic field adopting a FEM(Finite Element Method). The experimental results show that the developed caliper system can be used for the geometry pig with good performances.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.3
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• pp.246-251
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• 2012

This paper proposes a new position compensation method for misaligned Hall-effect sensors of BLDCM(Brushless DC Motor). If the Hall-effect sensors are installed at wrong position, the exact rotor position cannot be obtained. Therefore, when the BLDCM is controlled with this wrong position, the torque ripple can be increased and the average torque also decreases. The back-EMF of BLDCM can be obtained by using the voltage equation and by multiplying the back-EMF constant and rotor speed. At a constant speed, the estimated back-EMF by using the multiplication of the back-EMF constant and rotor speed is constant, but the estimated back-EMF from the voltage equation decreases at the commutation point because the line-to-line back-EMF of two conducting phases is start to decrease at this point. Therefore, by using the difference between these two estimated back-EMFs, the commutation point of the phase current can be determined and position compensation can be carried out. The proposed position correction method doesn't require additional hardware circuit and can be easily implemented. The validity of the proposed position compensation method is verified through several experiments.

• 연구논문집
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• s.30
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• pp.159-168
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• 2000

In this research, MFL inspection system has been studied for the inspection of storage tank floor. The reference specimens having 20%, 40%, 60% and 80% slot's are fabricated using the carbon steel plates of a 6mm and 10mm thick. Powerful permanent magnets and Hall effect sensors are used to this application. Also, this paper presents a newly developed MFL scanning system. Conclusively, it is shown that our system is able to detect metal loss like a slot.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.499-502
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• 2017

The needs of efficient electricity use and current measurement for electrical safety have been increased. Hence, the current sensor is used, especially non-contact current sensor which can measure the current without blocking the circuit using hall effect. However, the accurate measuring of the current sensor is inhibited due to the inflow of various noises in this current sensor. In this article, a stronger current sensor against the noise is proposed using low pass FIR filter to the existing current sensor. FIR filter was designed to block the range over the certain frequency at the output of the current sensor to eliminate the external noises, and so on. As a result, more accurate and close measurements were possible.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.2023-2025
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• 2002

We have fabricated a novel vertical trench-Hall device sensitive to the magnetic field parallel to the sensor chip surface. The vertical trench-Hall device is built on SOI wafer which is produced by silicon direct bonding technology using bulk micromachining, where buried $SiO_2$ layer and surround trench define active device volume. Sensitivity up to 350 V/AT is measured.

• Journal of the Korean Geotechnical Society
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• v.28 no.6
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• pp.39-52
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• 2012

Magnetic sensing system and automated monitoring system based on digital hall sensor for ground settlement are developed to change traditional method for monitoring surface settlement and underground settlement by manual type and to overcome technical limits of existing automated settlement monitoring system. It's possible to monitor surface settlement and underground settlement with multi-points at the same time in a single hole with NX size. It was possible to verify technical confidence and stability by several case studies of soft ground improvement project.