• 제목/요약/키워드: Current variation

검색결과 2,714건 처리시간 0.027초

주파수변화에 따른 형광램프 전압, 전류의 이론적 계산 (A Theoretical Calculation of Fluorescent Voltage and Current on Frequency Variation)

  • 이진우;남택주
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2003년도 학술대회논문집
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    • pp.233-235
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    • 2003
  • The voltage and current of fluoescent lamp has been successfully calculated in the case of frequency variation. Energy states of mercury atom in the discharge process are regarded as six levels. These calculations have been accurately solved by numerically employing mixed the FDM and the 2nd Runge-Kutta method. The theoretical calculation results and experimental results were presented to verify the feasibility of the modeling. Calculation and experimental results were presented to verify the feasibility of the calculation.

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지하철 직류 급전시스템의 표유전류 실태 분석(II) 부산 지역 (Analysis of the Stray Current Conditions in Subway DC Electrification System (II) Busan Metropolitan Area)

  • 하윤철;하태현;배정효;김대경;이현구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1367-1369
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    • 2004
  • When an underground pipeline runs parallel with subway DC electrification system, it suffers from stray current corrosion caused by the stray current from the rails negative returns. Perforation due to the stray current corrosion may bring about disastrous accidents such even in cathodically protected systems. Traditionally, bonding methods such as direct drainage, polarized drainage and forced drainage have been used in order to mitigate the damage on pipelines. In particular, the forced drainage method is widely adopted in Busan. In this paper, we report the real-time measurement data of the pipe-to-soil potential variation in the presence and absence of the IR compensation. The drainage current variation was also measured using the Stray Current Logger developed. By analyzing them, the problems of current countermeasures for stray current corrosion are discussed.

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한국수영만에서 잔차류장의 운동 .위치에너지의 계절변화 (Seasonal Variation of Kinetic and Potential Energy of Residual Flow Field in Suyoung Bay, Korea)

  • 김동선;유철웅
    • 한국환경과학회지
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    • 제6권4호
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    • pp.313-322
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    • 1997
  • 한국수영만에서 잔차류장의 운동 위치에너지의 계절변화를 연구하기 위하여 우리는 에너지의 수지를 계산하고 조석에너지와 비교했다. 위치에너지는 겨울과 봄철에 크며, 밀도성층이 형성된 여름과 초가을에 작게 나타났다. 잔차류의 운동에너지는 계절적인 변화를 보이고 있으며, 단위면 적당 잔차류의 평균 운동에너지는 6.4$\times$$10^{-4}ergs s^{-1}cm^{-}2$이다. 수영 만에서 잔차류장의 계절변동은 조석잔차류의 운동에너지가 밀도류나 취송류의 운동에너지보다 큰 11월을 제외하고는 밀도류가 지배하고 있다. 잔차류의 주성분인 조석잔차류, 취송류 및 밀도류의 운동에너지의 평균백분율은 잔차류의 운동에너지에 대하여 각각 29.1%, 3.4%, 67.5% 이다. 단위면적당 잔차류의 운동에너지, 위치에너지 및 조석에너지의 비는 각각 1.0 : 6.7$\times$$10^3$ : 8.2$\times$$10^4$ 이다.

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전류 검출기에 대한 연구 (A Study on current sensor)

  • Lee, Hwan
    • 대한전기학회논문지
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    • 제45권3호
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    • pp.335-340
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    • 1996
  • The item and structure of current detector depends on the current in conductors. The Hall current detector of these detectors is to use the variation of Hall voltage to conductor's current and it is very difficult for the conventional type to detect small current. In this paper we study experimented-method that detect AC current by using the magnetic modulation method the current, 0[mA]~100[mA]. The experiments results in 5 percent against the conventional, 20 percent in linear error, 0.12[.DELTA.mV/.DELTA.mA] to conventional type, 50[.DELTA.mV/.DELTA.mA] in sensitivity. (author). 7 refs., 15 figs.

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공간전하에 따른 전도전류의 변화에 대한 연구 (Study on the Effects of Space Charge on Conduction Current)

  • 최수일;이준호;김규언;김종민;황보승
    • 전기학회논문지
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    • 제59권12호
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    • pp.2225-2229
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    • 2010
  • In this study, we have investigated the effects of space charge on the conduction current with the variation of applied time of electric field in polymer insulators. We had also improved the PEA method, and then we could measure a simultaneously the space charge and the conduction current in insulators under the DC electric field. From this experiment, we have known the variation of conduction current due to the existence of space charge in XLPE1 and XLPE2.

고온에서 제조된 실리콘 주입 p채널 다결정 실리콘 박막 트랜지스터의 전기 특성 변화 연구 (A Study on Electric Characteristics of Silicon Implanted p Channel Polycrystalline Silicon Thin Film Transistors Fabricated on High Temperature)

  • 이진민
    • 한국전기전자재료학회논문지
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    • 제24권5호
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    • pp.364-369
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    • 2011
  • Analyzing electrical degradation of polycrystalline silicon transistor to applicable at several environment is very important issue. In this research, after fabricating p channel poly crystalline silicon TFT (thin film transistor) electrical characteristics were compare and analized that changed by gate bias with first measurement. As a result on and off current was reduced by variation of gate bias and especially re duce ratio of off current was reduced by $7.1{\times}10^1$. On/off current ratio, threshold voltage and electron mobility increased. Also, when channel length gets shorter on/off current ratio was increased more and thresh old voltage increased less. It was cause due to electron trap and de-trap to gate silicon oxide by variation of gate bias.

최대제어가능전류가 향상된 Corrugated P-베이스 BRT의 공정 변수에 따른 특성 변화 (Enhanced Maximum Controllable Current Characteristics of the Corrugated p-base BRT with Varying the Process Parameters)

  • 오재근;전병철;한민구;최연익
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제50권2호
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    • pp.57-59
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    • 2001
  • We investigated the maximum controllable current characteristics of the CB-BRT (Corrugated p-Base-Base Resistance Controlled Thyristor), which suppresses the snap-back effectively and increases the maximum controllable current(MCC) by employing the corrugated p-base. Experimental result shows that, when compared with conventional BRT, the MCC of the CB-BRT exhibits good stability on various process parameters. The MCC of the CB-BRT is larger than that of the conventional BRT by 50%, and the variation of the MCC in CB-BRT, caused by variation of the process parameters, is only 20% of that of the conventional BRT.

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비정질 실리콘 박막 트랜지스터 히스테리시스 특성의 온도의존성 (Temperature dependent hysteresis characteristics of a-Si:H TFT)

  • 이우선;오금곤;장의구
    • E2M - 전기 전자와 첨단 소재
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    • 제9권3호
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    • pp.277-283
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    • 1996
  • The temperature dependent characteristics of hydrogenerated amorphous silcon thin film transistor (a-Si:H TFT) with a bottom gate of N-Type <100> Si wafer were investigated. Drain current on the hysteresis characteristic curve showed an exponential variation. Hysteresis area of TFT increased with the gate voltage increased and decreased with the small gate voltage. According to the variation of gate voltages, drain current of TFT increased by temperature increase, and hysteresis characteristics mainly depended on the temperature increase. The hysteresis current showed negative characteristics curve over 383K. The hysteresis occurance area and the differences of forward and reverse sweep were increased at the higher temperature. Hysteresis current of I$_{d}$(on/off) ratio decreased at the lower temperature and increased at the higher temperature.e.

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열자극 탈분극전류 방법에 의한 BaTiO3의 분극 특성 연구 (Study on Polarization Properties of BaTiO3by Using Thermally Stimulated Depolarization Current)

  • 송호준;이용렬;박영준
    • 한국재료학회지
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    • 제12권8호
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    • pp.613-616
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    • 2002
  • The polarization properties of $BaTiO_3$ were investigated by using thermally stimulated depolarization current (TSDC) technique. Two peaks were observed at about 400 K (peak A) and 435 K (peak B) from TSDC spectra obtained from the temperature range of 280-500 K. Peak A shows a sharp decrease of TSDC due to extinction of spontaneous polarization above the phase transition temperature of $BaTiO_3$. The values of activation energy of peak A and peak B were calculated to be 0.70 eV and 0.87 eV respectively. From the results of TSDC measurement with a variation of polarizing electric field strength, we found that saturation of total current of TSDC was started from 3kV/cm. However, the amount of total current of TSDC was not affected by the variation of polarizing time.

Temperature Stable Current Source Using Simple Self-Bias Circuit

  • Choi, Jin-Ho
    • Journal of information and communication convergence engineering
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    • 제7권2호
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    • pp.215-218
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    • 2009
  • In this paper, temperature stable current and voltage references using simple CMOS bias circuit are proposed. To obtain temperature stable characteristics of bias circuit a bandgap reference concept is used in a conventional circuit. The parasitic bipolar transistors or MOS transistors having different threshold voltage are required in a bandgap reference. Thereby the chip area increase or the extra CMOS process is required compared to a standard CMOS process. The proposed reference circuit can be integrated on a single chip by a standard CMOS process without the extra CMOS process. From the simulation results, the reference current variation is less than ${\pm}$0.44% over a temperature range from - $20^{\circ}C$ to $80^{\circ}C$. And the voltage variation is from - 0.02% to 0.1%.