• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.142-145
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• 1995

This paper is to develop a measurement system of the displacement distance using ultrasonic sensors. Two 400KHz ultrasonic sensors are used for realizing the measurement system, such as one sensor transmits the sine wave and the other sensor receives this wave. The displacement is measured by the phase difference between transmitting and receiving signals. A phase defecter transforms phase difference to voltage. Because the output voltage pattern has nonlinear characteristics, the relations of the voltage and the distance are learned by a neural network. As the results of teaming, the efficiency of measurement system is improved. This system can measure the displacement distance at the accuracy of 1 micrometer level.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1658-1660
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• 2004

Use of higher voltage and higher capacity of power systems and their equipment is leading to an increase in the size of the entire system. In order to reduce the cost of constructing a substation, it is necessary to reduce the size of equipment. So, this paper described optical sensor, which exploited the electric and magnetic potentiometer to sense the measured voltage and current of medium voltage GIS. It can be used both in measurement and in protection relays as its well linearity, rapid response, broad dynamic range, wide frequency band, no magnetic saturation, small in volume, light weight, and saft in insulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.142-144
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• 2007

이 논문은 세탁기 모터 구동을 위한 단일 전류 센서 방식에서 3상 전류 복원 방법에 대한 기존 방법에 있어서의 문제점 개선 을 위하여 최소전압 주입 방식 과 Smooth 전압 주입 방식을 제시 하고 인버터에서의 전류 복원 향상을 통한 고조파 와 소음 개선 방법을 제시 하였다. 또한 제시된 방식의 타당성을 검증하기 위한 시뮬레이션 및 실험 결과를 고찰하는 것을 목적으로 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.86.3-86
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• 2001

Hall effect sensor using 7um, 1.7 ohm-cm or 10um, 3.5 ohm-cm Bipolar process was successfully developed. The Hall sensor consists of various patterns, such as regular shapes, rectangles, diamond, hexagon and cross shapes to optimize offset voltage and sensitivity for proper applications. In order to measure offset voltage in chip scale the Agilent company´s 4156C and Nano-Voltage Meter were used and the best structure in offset voltage was finally selected by using ceramic package. The patterns appear to be the quadri-rectangular patterns entirely and three-parallelogram patterns. The measured offset voltages were found to be about 173-365uV. Meanwhile, in ...

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.180-185
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• 2017

In this research, we proposed the simple and efficient method to calculate the shear stresses by using the mid-point measurements in ${\pm}45^{\circ}$ semiconductor resistor-sensor pair. Compared to the previous works, the measurements became much simpler by combining the approximation theory with the technique of mid-point measurement. In addition, we proposed another novel method for the stress calculation in which we could increase the sensitivity of the stress sensor by controlling the applied voltage between the sensor-pair. For the applied voltage of 8 V, the sensitivity showed a significant increase by 100%.

• 한국전기전자재료학회논문지
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• 제15권12호
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• pp.1045-1053
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• 2002

This paper describes characteristics of the developed current sensor by means of two identically wound magnetic cores forming a clamp like for measurement of a low DC, or AC current. This sensor consists of peak value detectors, a sensor of an electrically compensated current transformer type, a reference alternating voltage, Precision measuring circuits to measure the output signals of sensor with harmonics, and can be measured up to 2 A at DC, or AC current. The current sensor shows a measurement accuracy of less than 0.3% in the frequency range 40 Hz - 10 HBz. The resolution and sensitivity of the sensor were evaluated 0.1 mA and 10 mV/mA, respectively.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.812-817
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• 2008

A catalytic combustible sensor for LPG/LNG detection was fabricated on $Al_2O_3$ substrate using planar technology. The catalysts of Pd and Pt were added to ${\alpha}$- and ${\gamma}-Al_2O_3$ powders. The mixture of Pt, Pd and $Al_2O_3$ were homogenized by using a three roll mixer. TCR characteristics of Pt heater were optimized with the heat treatment temperature. Sensing properties were investigated as a function of the microstructure of $Al_2O_3$, the gas concentration and the variation of input voltage. ${\alpha}-Al_2O_3$ sintered at 500 $^{\circ}C$ is more suitable as LPG/LNG sensor due to good grain shape and size distribution of about 300 nm than that of ${\gamma}-Al_2O_3$ which is in irregular shape and with a particle size of 5-30 ${\mu}m$. The sensor has shown maximum output voltage of 14 mV for 1000 ppm $C_4H_{10}$ and 3.8 mV for 1000 ppm $CH_4$ at 5.0 V input voltage.

• 한국기계가공학회지
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• 제18권5호
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• pp.1-8
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• 2019

Breath analysis using a portable device is better than the classical breath analysis system in terms of installation and operation. There is an increasing need to develop cost-effective equipment for testing gas sensors from the viewpoint of functionalities that can be applied applicable to portable devices. In the present study, an economical gas chamber for in-situ gas measurement is implemented with a single gas chamber without using expensive gas storage and control equipment; the gas response characteristics are analyzed using the above-described chamber. The main features of the implemented gas chamber are simple injection procedure, improved gas diffusion, easy measurement and cleaning, support for low-power mode measurement function for portable devices, and open source platform. Moreover, an analysis of gas response characteristics based on changes in sensor voltage show that the sensitivity and 90% response time are affected by the sensor voltage. Furthermore, the sensitivity graph has an inflection point in a specific range. The gas sensor applied in this study showed fast response speed and high sensitivity for sensor voltages of 3.0-3.5 V, regardless of the concentration of acetone gas, the target gas used in this study.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.93-102
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• 2011

In deeply scaled CMOS technologies, two major non-ideal factors are threatening the survival of the CMOS; i) PVT (process, voltage, and temperature) variations and ii) leakage power consumption. In this paper, we propose a novel post-silicon tuning methodology to scale optimum voltage and frequency "dynamically". The proposed design technique will use our PVT sensor circuits to monitor the variations and based on the monitored variation data, voltage and frequency will be compensated "automatically". During the compensation process, supply voltage is dynamically adjusted to guarantee the minimum total power consumption without violating the frequency requirement. The simulation results show that the proposed technique can reduce the total power by 85% and the static power by 53% on average for the selected ISCAS'85 benchmark circuits with 45 nm CMOS technology compared to the results of the traditional PVT compensation method.

• 센서학회지
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• 제5권3호
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• pp.9-16
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• 1996

본 논문에서는 고전압 임펄스전압 발생장치의 조작에 의하여 발생하는 과도전압을 측정할 수 있는 용량성분 압기를 실현하였다. 전장센서를 이용한 과도전압측정계는 고속응답의 평판형 전장센서와 광대역 전압버퍼로 구성되었으며, 사용된 전압버퍼(LH0033)의 입력임피던스는 $10^{12}{\Omega}$ 정도로 대단히 높다. 단위계단 응답특성을 파악하기 위하여 새로운 교정방법을 제안하고, 설치조건에 따른 분압비 오차를 검토하였으며, 분압비 오차를 0.5% 이내로 하기 위한 최적설치조건을 제시하였다. 교정실험으로부터 과도전압측정계의 응답시간은 약 15.78 ns이었으며, 주파수대역은 6.37 Hz에서 27.3MHz이다. 따라서 본 측정계로 과도과전압은 물론 상용주파수전압도 신호의 일그러짐 없이 측정이 가능하였다.