• Title/Summary/Keyword: 광전센서

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Electrical Characteristics of Optical Current Transducer on Gas Insulated Switchgear (GIS용 광CT의 전기적 특성)

  • Lee, Su-Woong;Lee, Sung-Gap;Noh, Hyeon-Ji;Ahn, Byeong-Rib;Won, Woo-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.319-320
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    • 2007
  • We researched basic study about electrical characteristics of Zinc Selenide (Faraday Cell), which is known for various temperature of good-performance, that applied measuring current or protecting instrument by Optical Current Transducer, on Gas Insulated Switchgear. Measuring System consists of VCSEL produced 850nm IR Laser, Pin Photo Diode made of GaAs surveyed as Optical Power Meter, and Optical Fibers specified Multi-mode. We observed optical output changes during measurement of currents increasing by 100[A] in range from 0[A] to 1,000[A] and set temperature condition increasing by $5[^{\circ}C]$ in a range from $30[^{\circ}C]\;to\;60[^{\circ}C]$.

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Recent Research Trend in Ferroelectrics for Effective Photovoltaics (태양전지 효율향상을 위한 강유전체의 연구동향)

  • Bark, Chung Wung
    • Prospectives of Industrial Chemistry
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    • v.24 no.1
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    • pp.3-13
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    • 2021
  • 강유전체는 특유의 높은 유전상수와 자발분극으로 인해 반도체 소자 및 센서 등에서 널리 활용되어 왔다. 강유전체의 특성을 활용하여 광전소자에서 형성된 전하를 원하는 방향으로 쉽게 이동시킬 수 있는 특성을 가지고 있어 광전소재와 결합 시 특성 향상이 가능한 것으로 알려져 있다. 그러나 강유전체와 기존 태양전지와의 융합 연구들은 기초적인 단계의 연구가 산발적으로 진행되고 있으나, 아직 실용화 단계에는 이르지 못하고 있다. 본 서지에서는 최근에 활발히 연구되기 시작한 강유전 기반 광소자와 그 관련 연구를 소개하고자 한다. 특히 강유전체 자체를 활용한 태양전지와 유기태양전지, 실리콘 태양전지, 페로브스카이트 태양전지 등 최근 가장 활발히 연구되고 있는 태양전지 소재와 강유전체를 결합한 새로운 태양전지의 연구동향을 다룰 고자 한다. 이와 같은 자발분극에 의한 캐리어 이동의 변화는 에너지 소자 전반에 기여할 수 있을 것이다.

A Study on the Implementation of SoC for Sensing Bio Signal (인체신호 측정을 위한 SoC 구현에 관한 연구)

  • Sun, Hye-Seung;Song, Myoung-Gyu;Lee, Jae-Heung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.109-114
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    • 2010
  • In this paper, the implementation of a human signal sensing module that has capabilities to check and restore the weak signals from the human body is presented. A module presented in this paper consists of processing and sensing elements related to human pulse and body temperature and a controller implemented with SoC design method. PPG data is detected by a noise filtering process toward the amplified signal which is from the operating frequency between 0.1Hz - 10Hz. A digital temperature sensor is used to check the body temperature. A sensor outputs the corresponding value of the electric voltage according to the body temperature. Moreover, this paper discusses the implementation of an enhanced microprocessor which is synthesized with VHDL as a part of the SoC development and used to control the entire module. The SoC processor is implemented on a Xilinx Spartan 3 XC3S1000 device and has the achieved operating frequency of 10MHz. The implemented SoC processor core is successfully tested with macro memories in FPGA and the experimental results are hereby shown.

Implementation of Heart Rate Monitoring System using PPG Sensor (PPG 센서를 이용한 심박 모니터링 시스템 구현)

  • Lee, Won-Seok;Jung, Kyung Kwon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.5
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    • pp.138-142
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    • 2017
  • Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. It is often used non-invasively to make measurements at the skin surface. In this paper, we described the implementation heart rate monitoring system using PPG sensor. Proposed system is collected data using PPG sensor and heart rate was detected using second derivative method. In order to verify the effectiveness of the proposed method, we performed the measurements of RR-intervals with a commercial medical device.

Synthesis and Optoelectronic Characteristics of Ag2Se Nanoparticle for NIR Sensor Application (근적외선 센서를 위한 Ag2Se 나노 입자 합성 및 광전기적 특성)

  • Jang, Jaewon
    • Journal of Sensor Science and Technology
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    • v.28 no.4
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    • pp.266-269
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    • 2019
  • In this study, $Ag_2Se$ nanoparticles were synthesized by employing the colloidal method. The synthesized $Ag_2Se$ nanocrystals were spherical in shape with a diameter of approximately 4 nm and had high crystallinity. These attributes of $Ag_2Se$ nanocrystals were determined through images obtained from a high resolution transmission electron microscope. Thin films comprising the synthesized $Ag_2Se$ nanoparticles had an optical band gap of 1.5 eV. Furthermore, fabricated NIR sensors comprising $Ag_2Se$ nanoparticles exhibited a high detectivity of $5.5{\times}10^9$ Jones (above $1{\times}10^9$) at room temperature, leading to low power consumption

Implantation of DC Optical Current Sensor Based on Faraday Effect for HVDC (페러데이 효과를 이용한 특고압 직류전송용 광전류 센서 구현)

  • Kim, Kwang Taek;Chung, Dae Won;Kim, Young Soo
    • Journal of Sensor Science and Technology
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    • v.28 no.3
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    • pp.187-190
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    • 2019
  • We proposed and demonstrated DC(direct current) optical current sensor based on Faraday effect for HVDC(high voltage direct current). The RIG((Bi1.3Gd0.43Y1.27)Fe5O12) was adopted as Faraday device because of its high Verdet constant and good thermal stability. The differential amplification scheme for signal processing was present. The sensor showed high linear response for the input current. Measurement range of the sensor was 0~200A and measurement error was less than 1%.

Growth of $CdS_{0.67}Se_{0.33}$ single crystal by sublimation method and their photoconductive characteristics (승화법에 의한 $CdS_{0.67}Se_{0.33}$ 단결정 성장과 광전도 특성)

  • Hong, K.J.;Lee, S.Y.
    • Journal of Sensor Science and Technology
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    • v.7 no.2
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    • pp.131-139
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    • 1998
  • $CdS_{0.67}Se_{0.33}$ single crystal was grown by vertical sublimation method of closed tube physical vapour deposition. The (0001) growth plane of oriented single crystals was confirmed from the back-ref1ection Laue patterns. From the Hall effects by van der Pauw method, the as-grown $CdS_{0.67}Se_{0.33}$ single crystals were found to be n-type semiconductors. The mobility appeared to be decreased by lattice scattering at temperature range from 150K to 293K and by impurity scattering at temperatures ranging from 30K to 150K In order to explore its applicability in photoconductive cells, we measured the ratio of photo-current to dark-current (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time respectively. The results indicated that for the samples annealed in Cu vapour the photoconductive characteristics are best. We obtained sensitivity of 0.99, the value of pc/de of $1.84{\times}10^{7}$, the MAPD of 323mW and the rise and decay time of 9.3 ms and 9.7 ms, respectively.

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Structural and photoelectrical properties of copper phthalocyanine(CuPc) thin film on Si substrate by thermal evaporation (Si 기판위에 열증착법으로 제조한 copper phthalocyanine(CuPc) 박막의 구조 및 광전특성)

  • Lee, Hea-Yeon;Jeong, Jung-Hyun;Lee, Jong-Kyu
    • Journal of Sensor Science and Technology
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    • v.6 no.5
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    • pp.407-413
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    • 1997
  • The crystallized CuPc(copper phthalocyanine) film on a p-type <100> Si substrate is prepared at the substrate temperature of $300^{\circ}C$ by thermal evaporation. X -ray diffraction analysis showed the CuPc film to have a-axis oriented structure. For the measurement of photovoltaic characteristics of the CuPc/Si film and the Si substrate, a transverse current-voltage (I-V) curve is observed. In the dark, the Au/Si junction is shown to be ohmic contact. However, under illumination, a photovoltaic effect is not observed. The I-V curve in the dark indicates that the CuPc film on Si may form an ohmic contact. Since the CuPc film is a p-type semiconductor, the CuPc/p-Si junction has no barrier at the interface. Under illumination, the CuPc/Si junction shows a large photocurrent comparing with that of the wafer. The result indicates that the CuPc layer plays an important role in the photocarrier generation under red illumination (600 nm). The CuPc/Si film shows the photo voltaic characteristics with a short-circuit photocurrent ($J_{sc}$) of $4.29\;mA/cm^{2}$ and an open-circuit voltage ($V_{oc}$) of 12 mA.

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Growth of CdS Single Crystal as Photoconductor and Its Physical Characteristics (광전도체의 CdS 단결정 성장과 물리적 특성)

  • Jeong, T.S.;Yu, P.Y.;Shin, Y.J.;Shin, H.K.;Kim, T.S.;Jeong, C.H.;Lee, H.;Shin, Y.S.;Hong, K.J.;Rheu, K.S.
    • Journal of Sensor Science and Technology
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    • v.2 no.1
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    • pp.109-115
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    • 1993
  • A CdS single crystal was grown by using sublimation method. Lattice constants, $a_{o}$ and $c_{o}$, obtained by using extrapolation were $4.131{\underline{8}}{\AA}$ and $6.712{\underline{2}}{\AA}$, respectively. The carrier density was${\sim}10^{23}m^{-3}$ and the mobility was $2.93{\times}10^{-2}m^{2}$/V sec from measured Hall data at room temperature. The mobility has a increasing tendency in proportion to $T^{1/2}$ from 33 K to 150 K and a decreasing tendency in proportion to $T^{-2}$ from 180 K to room temperature. The short wavelength band peak measured from photocurrent was due to intrinsic transition, and the energy value of this peak was equal to the energy band gap of CdS photoconductor.

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Low Speed Weigh-In Motion System Using Multi-FBG Sensors (다중 광섬유 브라그 격자 센서를 적용한 저속용 자동계중 시스템)

  • Lee Hojoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.1
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    • pp.21-28
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    • 2004
  • We have demonstrated a low speed weigh-in motion system using FBG sensors and performed field test at a trial road. Technique, called identical chirped grating interrogation, have used for a demodulation relying on the mismatching of two identical broadband chirped gratings. We compensated the fluctuation of LED power and the temperature of sensor and used a lock-in amplifier to reduce effect of noise. We could design a bending plate that the measurement results are independent of position of weight. The FBG sensors weigh-in motion system showed linearity and reproducibility.