• 한국엔터테인먼트산업학회논문지
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• 제5권2호
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• pp.166-172
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• 2011

저가의 홀센서를 이용하여 자석의 위치를 인식하는 센서 시스템을 제안하였다. 먼저 모델식을 이용하여 자석에 의한 자기장을 측정하고, 수평 자계와 수직 자계의 특성을 분석하여, 센서의 배치방법을 결정하였다. 자석과 홀센서의 위치 관계에 따라서 측정된 자기장 값으로부터 자석의 위치를 추정하는 알고리즘을 제안하고, 이론적인 오차를 계산하였다. 또한 마이크로 컨트롤러를 사용하여 개발할 때의 단점인 실시간 데이터 확인이 어려운 점을 극복하기 위해서 컴퓨터용 응용 프로그램을 작성하여, 작업의 수월성을 높였다. 계산된 이론적 오차는 0.0025cm 이하로 나타났으며 실제로 개발된 시스템의 오차는 0.07cm 이하로 측정되어 여러 가지 상황에서 제안한 방법들의 우수성을 입증하였다.

• 한국전기전자재료학회논문지
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• 제15권8호
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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.

• Journal of Magnetics
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• 제9권2호
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• pp.47-51
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• 2004

Giant magneto-impedance (GMI) effect in zero-magnetostrictive Co-based amorphous ribbons samples in their as-quenched and stress-released states as well as with intentionally induced magnetic anisotropy were investigated. Magnetic and impedance properties of the samples exhibiting different anisotropy were compared and the optimum operation conditions for the studied samples from the view-point of their utilization as a sensor element have been determined. A design of a model of magnetic field sensor and characteristics of the constructed prototype are presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1689-1693
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• 2004

This paper proposes a vehicle detector with a magnetoresistive (MR) sensor. The detector consists of a MR sensor and mechanical and electronic apparatuses. Composed of six magnetically variable resistors, the MR sensor senses disturbance of the earth's magnetic field caused by a moving vehicle over itself and then produces an output indicative of the moving vehicle. Experiments have been carried out with three stages. At the first stage, the outputs of the sensor have been analyzed to show the validity of the detector's circuit and the detecting method. At the second stage, the detector has been tested on a local highway in Korea. Through the field tests, the outputs of the detector in response to various kinds of moving vehicles have been collected and analyzed. At the final stage, to verify the performance of the detector, traffic volumes on the highway have been measured with the detector and compared with the exact traffic volumes in a highly congested traffic.

• Journal of Magnetics
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• 제12권4호
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• pp.156-160
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• 2007

In this paper, we analyze the errors associated with magnetic field interference for fiber-optic current sensors working in a three-phase electric system and provide a solution to compensate the interference. For many practical conductor arrangements, the magnetic filed interference may cause errors unacceptable for the accuracy requirements of the sensors. We devised a real time compensation method for the interference by introducing geometric and weight factors. We realized the method using simple electronic circuits and obtained the real time compensated outputs with errors of ${\pm}1%$.

• 센서학회지
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• 제26권3호
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• pp.186-191
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• 2017

In this study, we investigated the simultaneous detection properties of organic vapor, pressure difference, and magnetic field using a single rugate-structured free-standing porous silicon (RFPS) thin film. Both the wavelength and the intensity of the rugate peaks were changed in the reflectivity spectrum measured at the thin film surface while the organic vapor was exposed to the RFPS thin film. However, when the pressure difference and the magnetic field were exposed to the film, only the rugate peak intensity was changed. Therefore, it is possible to distinguish whether or not the organic vapor is detected by simultaneously changing the rugate peak wavelength and intensity. In addition, a method of distinguishing between the pressure difference and the magnetic field detection signal has been derived by rapidly modulating the direction of the magnetic field. This study shows that it is possible to simultaneously detect and distinguish various objects using a single RFPS thin film, and it is found that porous silicon can be utilized as a sensor sufficiently.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.124-128
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• 1995

We have fabricated the vacuum magnetic device with a lateral field emitter arrays constructed on n-Si wafer, and investigated its magnetic characteristics. The device is consited to tip-arrayed emitter. gate and split-anode, The fabricated vacuum magnetic device has showed a good linearity of magnetic field and a high sensitivity compared with the conventional semiconductor magnetic device.

• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.49-55
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• 2016

Nowadays there are magnetic sensors in a wide variety of equipment such as computers, cars, airplanes, medical and industrial instruments. In many of these applications the magnetic sensors offer safe and non-invasive means of detection and are more reliable than other technologies. The electric current in a conductor generates a magnetic field detected by this type of sensor. This work aims to define a package dedicated to an electrical current sensor using a MTJ (Magnetic Tunnel Junction) as a sensing device. Four different proposals of packaging, three variations of the chip on board (CoB) package type and one variation of the thin small outline package (TSOP) were analyzed by COMSOL modeling software by simulating a brad range of current injection. The results obtained from the thermal and magnetic analysis has proven to be very important for package improvements, specially for heat dissipation performance.

• 한국초전도ㆍ저온공학회논문지
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• 제22권4호
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• pp.1-5
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• 2020

Heart consists of myocardium cells and the electrophysiological activity of the cells generate magnetic fields. By measuring this magnetic field, magnetocardiogram (MCG), functional diagnosis of the heart diseases is possible. Since the strength of the MCG signals is weak, typically in the range of 1-10 pT, we need sensitive magnetic sensors. Conventionally, superconducting quantum interference devices (SQUID)s were used for the detection of MCG signals due to its superior sensitivity to other magnetic sensors. However, drawback of the SQUID is the need for regular refill of a cryogenic liquid, typically liquid helium for cooling low-temperature SQUIDs. Efforts to eliminate the need for the refill in the SQUID system have been done by using cryocooler-based conduction cooling or use of non-cryogenic sensors, or room-temperature sensors. Each sensor has advantage and disadvantage, in terms of magnetic field sensitivity and complexity of the system, and we review the recent trend of MCG technology.

• 한국군사과학기술학회지
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• 제21권4호
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• pp.456-463
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• 2018

With the development of weapon systems by mounting various sensors, it makes important to analyze the precise functioning of sensor to external environment. In the case of small arms with magnetic sensor, the malfunction of small arms might be caused by strong external magnetic fields. In this study, the effects of magnetic sensor on external magnetic fields were analyzed, and optimal magnetic shield and shield structure were designed through M&S. In addition, the magnetic-shielding effectiveness of magnetic sensor in small arms was verified with commercial shielding materials. As a result, it was demonstrated that the Fe-Cu-Si-Nd-B with the structure of multi-layer metallic shields was shown the magnetic-shielding effectiveness of 83 % for an external permanent magnet and 19 % for an alternating magnetic field of 180 dBpT at 60 Hz, respectively.