• Title/Summary/Keyword: Current characteristics

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The Design of CMOS Second Generation Current Conveyor (CMOS Second Generation Current Conveyor의 설계)

  • 오재환;김상수이영훈
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.1037-1040
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    • 1998
  • In this paper, current conveyor building block is introduced and CMOS realization of this block is given. The input-impedance characteristics, current-transfer characteristics and voltage-transfer characteristics of this proposed current conveyor circuit are given. This characteristics of the CMOS current conveyor circuit is useful of the various applications which require a wideband. Using the Spice tool, the circuit is designed and the characteristics of CMOS current conveyor circuit is considered. Finally, refer to the simple applications.

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High Temperature Characteristics of submicron GaAs MESFETs (고온 동작 MESFET 의 온도특성 해석)

  • 원창섭;유영한;신훈범;한득영;안형근
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.379-382
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    • 2002
  • GaAs has wide band gap, Therefore that malarial can used high Temperature application. in this paper explain to current-voltage characteristics of thermal effect. we experiment on thermal test of current-voltage characteristics and gate leakage current with real device. As a result, we propose a current-volatage characteristics model. that model base on gate leakage current, and gate leakage current influence gate source voltage.

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Comparisons of gain design of the current controller with the first order lag characteristics (1차 지연 특성을 갖는 전류 제어기의 이득 설계 비교)

  • Lee, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2019.07a
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    • pp.412-413
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    • 2019
  • This paper deals with the comparisons of gain design of current controller with the first order lag characteristics. Usually the current controller for motor drives and PCSs has the first order lag characteristics to avoid the current overshoot. This paper suggests a new inductor current controller for the PCSs and also compares with other two current controllers. The simulation results show that the proposed design method also gives the first order lag characteristics and can be used as an alternative current controller for PCSs.

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Recovery Characteristics of a Flux-lock Type HTSC Fault Current Limiter after Fault Removal (자속구속형 고온초전도 사고전류 제한기의 사고제거 후 회복특성)

  • Lim, Sung-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.9
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    • pp.812-815
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    • 2007
  • To apply the superconducting fault current limiter(SFCL) into a power system, the analysis for its recovery characteristics as well as the consideration for its cooperation with other protecting machine such as a circuit breaker is required. The recovery characteristics of the flux-lock type SFCL like its current limiting characteristics are dependent on the winding direction of two coils. In this paper, the experiments of the current limiting and the recovery characteristics of the flux-lock type SFCL with YBCO thin film were performed. From the analysis on the experimental results due to the winding direction of two coils, the limited fault current in case of the additive polarity winding was observed to be lower than that for the case of the subtractive polarity winding. In addition, the recovery time was found to be faster in case of the additive polarity winding compared to the subtractive polarity winding.

Current-Voltage-Luminance Characteristics Depending on a Direction of Applied Voltage in Organic Light-Emitting Diodes

  • Kim, Sang-Keol;Hong, Jin-Woong;Kim, Tae-Wan
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.1
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    • pp.38-41
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    • 2002
  • We have investigated current-voltage-luminance characteristics of organic light-emitting diodes based on TPD/Alq$_3$organics depending on the application of forward-backward bias voltage. Luminance-voltage characteristics and luminous efficiency were measured at the same time when the current-voltage characteristics were measured. We have observed that the current-voltage characteristics shows a reversible current maxima at low voltage, which is possibly not related to the emission from Alq$_3$. Current-voltage-luminance characteristics imply that the conduction luminance mechanism at low voltage is different from that of high voltage one.

Study on Current and Water Quality Characteristics in Yongil Bay (영일만내의 유동과 수질특성에 관한 연구)

  • 김헌덕;김종인;류청로
    • Journal of Ocean Engineering and Technology
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    • v.15 no.4
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    • pp.28-37
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    • 2001
  • The water quality in Yongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex. The study aims to simulate the current system that is necessary to build ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D model baroclinic model which considers tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most applicable on appearing the current system of the stratificated Yongil Bay difference of density. Form the results of simulation considered tidal current only, it can be clarified that the water body flows in the inner bay through the bottom layer and flows out the outer bay through the surface layer in Yongil Bay. And the fresh water from the Hyongsan river and the thermal discharge form POSCO have a little effect on the current system in Yongil Bay, but the diffusion of heat and salt has an important effect upon the formation of the density stratification of the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system in Yongil Bay.

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Study on Current and Water Quality Characteristics in Yongil Bay (영일만내의 유동과 수질특성에 관한 연구)

  • 김헌덕;김종인;류청로
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.246-252
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    • 2000
  • The water quality in Yeongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex The study aims to simulate the current system that is necessary to built ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D baroclinic model considered tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most appliable on the Yongil Bay where current flows slowly and the flow direction is varied by depths. From the results of simulation considered tidal current only, It am be clearly said the water in Yongil Bay flows in through the surface layer and flows out through the bottom layer. And the fresh water from the Hyongsan river and the heated discharge from POSCO have little effect on the current structure in Yonggil Bay, but have and important effect upon the density structure by diffusion of heat and salt. And the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system.

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Hysteresis Characteristics of Flux-Lock Type Superconducting Fault Current Limiter (자속구속형 고온초전도 사고전류제한기의 히스테리시스 특성)

  • Lim, Sung-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.66-70
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    • 2007
  • For the design to prevent the saturation of the iron core and the effective fault current limitation, the analysis for the operation of the flux-lock type superconducting fault current limiter (SFCL) with consideration for the hysteresis characteristics of the iron core is required. In this paper, the hysteresis characteristics of the flux-lock reactor, which is an essential component of the flux-lock type SFCL, were investigated. Under normal condition, the hysteresis loss of the iron core in the flux-lock type SFCL does not happen due to its winding structure. From the equivalent circuit for the flux-lock type SFCL and the fault current limiting experiments, the hysteresis curves could be drawn. From the analysis for both the hysteresis curves and the fault current limiting characteristics due to the number of turns for the 1st and 2nd windings, the increase of the number of turns in the 2nd winding of the flux-lock type SFCL had a role to prevent the iron core from saturation.

Effect of Electric Current on Friction Characteristics of Machine Driving Elements (기계구동 부재의 마찰특성에 미치는 전류의 영향)

  • Jun, Sung-Jae;Cho, Yon-Sang;Park, Heung-Sik
    • Tribology and Lubricants
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    • v.18 no.5
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    • pp.339-344
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    • 2002
  • Whenever moving surfaces of machine driving elements interact in air and lubricating oil, oxidization film on the surfaces are generated. It is effect to prevent friction and wear on contact area. Since the electronic current progress the oxidization of metal, if the electronic flow be regulated, the thickness of oxidization film can be regulated and friction characteristics can be improved. But the electronic current can deteriorate friction characteristics, so various characteristics must be investigated on transforming of electronic current. Therefor, using the Norton equation in this study, short current were transformed between frictional materials using ball on disk type tester. It was studied on effect of electronic current for friction characteristics.

Improvement of Current Limiting and Recovery Characteristics of Flux-Lock Type SFCL with Series Connection of Two Coils Using Its Third Coil

  • Ko, Seok-Cheol;Kim, Young-Pil;Lim, Sung-Hun
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.472-477
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    • 2017
  • In this work, the current limiting and recovery characteristics of a flux-lock type superconducting fault current limiter (SFCL) with series connection of two coils were effectively improved by adding a third winding into the conventional flux-lock type SFCL with series connection of two coils. To confirm the contribution of the third winding to the current limiting and recovery characteristics of this type of the SFCL, short-circuit testing was carried out with consideration of the third winding, and the effect of the third winding on the current limiting and recovery characteristics was examined by comparative analysis of the amplitude of the limited fault current and the power burden of the high-TC superconducting (HTSC) element comprising the SFCL. Through the analysis of both the limiting impedance and the operational current as the main design parameter of the SFCL, the improved current limiting and recovery characteristics of the flux-lock type SFCL using the third winding could be verified.