• Title/Summary/Keyword: Current control device

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Development of an Electronic Starting Controller for Starting Motor of Packaged Power Systems (이동식발전설비의 기동전동기용 전자식 시동 제어장치 개발)

  • Kim, Jong-Su;Yoon, Kyoung-Kuk;Seo, Dong-Hoan
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.5
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    • pp.700-706
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    • 2012
  • The core technology of a starting device in the packaged power system is the pinion gear shifting device and to limit the initial starting voltage. Although the conventional products have been used the starting controller using mechanical contactor, these have a big problem such as the uncertainty for the start of starting motor after a pinion gear is completely shifted or the arc demage due to high current. In this study, in order to solve these problems, we designed and fabricated a new product to achieve the safety and reliability as follows: the pinion gear-shifting control circuits to eliminate the uncertainty of the start, the starting control system using semiconductor device to prevent the arc demage of contactor caused by high current, a start safety devices for soft starting of series motor. In addition, we obtained the electrical safety by separating the pinion gear control circuit and the source circuit of motor.

A Study on the Dielectric Property Organic Ultra Thin film (유기초박막의 유전특성에 관한 연구)

  • Kim, Dong-Kwan;Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2001.11a
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    • pp.87-89
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    • 2001
  • The structure of manufactured device is Cr-Au/Arachidic acid/Al, the number of accumulated layers are 13, 17 and 19. The I-V characteristic of the device is measured from -2[V] to +2[V] and the characteristic of current-time of the devices. We have investigated the capacitance because this fatty acid system have a accumulated layers. The maximum value of measured current is increased as the number of accumulated layers are decreased. The capacitor properties of a thin film is better as the distance between electrodes is smaller. The results have shown the insulating materials and could control the conductivity by accumulated layers.

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Realization of Static Image on OLEO using Photoluminescence Degradation (PL Degradation을 활용한 OLED 소자의 사진 이미지 구현)

  • Suh, Won-Gyu;Moon, Dae-Gyu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.9
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    • pp.859-862
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    • 2008
  • We have realized static image on organic light emitting diodes (OLEDs) using photoluminescence degradation. Ultraviolet (UV) was irradiated to the glass side of device. UV power was 350 Wand the wavelength was 365 nm. The UV irradiation gives rise to the degradation of photoluminescence. Due to the degradation, the current density-voltage curve was shifted to the higher voltage side and the luminescence was also degraded by the current and photoluminescence drop. The negative imaged films were prepared to control the transmittance of UV. The UV light was passed through the film. By this method, the film image was transferred to the device with reversed image and the static image was realized on the OLED.

Magnetic Sensitivity Improvement of Silicon Vertical Hall Device (Si 종형 Hall 소자의 자기감도 개선)

  • Ryu, Ji-Goo;Kim, Nam-Ho;Chung, Su-Tae
    • Journal of Sensor Science and Technology
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    • v.20 no.4
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    • pp.260-265
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    • 2011
  • The silicon vertical hall devices are fabricated using a modified bipolar process. It consists of the thin p-layer at Si-$SiO_2$, interface and n-epi layer without $n^+$buried layer to improve the sensitivity and influence of interface effects. Experimental samples are a sensor type I with and type H without p+isolation dam adjacent to the center current electrode. The experimental results for both type show a more high current-related sensitivity than the former's vertical hall devices. The sensitivity of type H and type I are about 150 V/AT and 340 V/AT, respectively. This sensor's behavior can be explained by the similar J-FET model.

Control of Background Doping Concentration (BDC) for Electrostatic Discharge (ESD) Protection of High Voltage Operating LDI Chip (고전압용 LDI 칩의 정전기 보호를 위한 EDNMOS 소자의 백그라운드 도핑 특성)

  • Seo, Yong-Jin;Kim, Kil-Ho;Lee, Woo-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.140-141
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    • 2006
  • Background doping concentration (BDC) is proven to be a critical factor to affect the high current behavior of the extended drain NMOSFET (EDNMOS) devices. The EDNMOS device with low BDC suffers from strong snapback in the high current region, which results in poor electrostatic discharge (ESD) protection performance and high latchup risk. However, the strong snapback can be avoided in the EDNMOS device with high BDC. This implies that both the good ESD protection performance and the latchup immunity can be realized in terms of the EDNMOS by properly controlling its BDC.

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Current Control of Voltage Source Inverter (전압원 인버터의 전류제어)

  • Ma, J.S.;Youn, H.S.;Im, S.W.;Goo, B.H.;Kwon, W.H.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.328-332
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    • 1996
  • Current controlled inverter is the device which gives fast and accurate current output response for current command Existing current controlled inverters have no way but to take a narrow bandwidth due to resonance of output filter. In this paper, High performance current controlled inverter with multiloop structure is designed and modeling is executed in that basis. This paper realizes the high performance current controlled inverter with the bandwidth above resonant frequency, controls proposed inverter by analog controller, analyzes the performances through simulation and tests 2kW prototype system.

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Output performance of current transformer on over-current (직류분전류를 포함한 과전류에 대한 변류기의 출력특성)

  • Jung, Heung-Soo;La, Dae-Ryeol;Kim, Sun-Koo;Roh, Chang-Il;Kim, Won-Man;Lee, Dong-Jun
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.951-953
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    • 2005
  • The current transformer is used for the insulation of measuring instrument, enlargement of measurement scope, standardization of measuring instrument, control of protective device. It's required various performance as the intention of service, site of establishment, insulation. especailly, current transformer has small ratio errors. if current transformer has large ratio error, it's caused a electricity failure. so in this paper, we examine the theory of current transformer, major factor of errors, output performance on over-current.

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Low Leakage Input Vector Searching Techniques for Sequential Circuits (시퀀셜 회로를 위한 리키지 최소화 입력 검색방법)

  • Lee, Sung-Chul;Shin, Hyun-Chul;Kim, Kyung-Ho
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.655-658
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    • 2005
  • Due to reduced device sizes and threshold voltages, leakage current becomes an important issue in CMOS design. In a CMOS combinational logic circuit, the leakage current in the standby state depends on the state of the inputs and thus can be minimized by applying an optimal input when the circuit is idling. In this paper, we present a New Input Vector Control algorithm, called Leakage Minimization by Input vector Control (LMIC) for minimal leakage power. This algorithm finds the minimal leakage vector and reduces leakage current up to 22.% on the average, for TSMC 0.18um process parameters. Minimal leakage vectors are very useful in reducing leakage currents in standby mode of operation.

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Design and Fabrication of a Conductively Cooled Cryostat by Cryocooler (냉동기 부착형 전도냉각식 Cryostat의 설계 및 제작)

  • Bae, Joon-Han;Sim, Ki-Deck
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.11
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    • pp.1921-1924
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    • 2007
  • In order to measure the superconducting transition temperature, the critical current and the alternating current(AC) loss on short samples of high temperature superconductor, a cryocooler cooled cryostat has been designed and built. Two closed-cycle coolers provide cooling with an ultimate sample temperature below 16K. Temperature regulation is provided by 50W of electrical heater that opposes the cooling power from the cold heads. Temperature control feedback is by means of a cernox temperature sensor co-located with the heaters on the second stage of the cold head. Additional temperature sensors are located on the sample mount(B1), on the CVI cold head(B2) and on the Dakin cold head(B3). AC losses on the sample high temperature superconductor were measured at 30K so that the developed device performance was evaluated. In this paper, the design, fabrication and test results on the cryocooler cooled cryostat are presented.

Performance improvement of stepping motor driver using the CPLD (CPLD를 이용한 2상 스테핑 모터 드라이버의 성능개선)

  • O, Tae-Seok;Kim, Il-Hwan
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.910-915
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    • 2003
  • This paper describes the design of a 2-phase stepping motor driver using CPLD(Complex Programmable Logic Device). The driver IC such as L297 (SGS-Thomson Microelectronics), which is mostly used has some problems in PWM control because of the switching noise of power MOSFETs. It causes current ripple and acoustic noise. To improve theses characteristics, we proposed a new current control method that the output PWM frequency is almost constant using a digital filter. Also we proposed constant current method for 1-2 phase(half step) excitation. The proposed method is implemented with CPLD(Xilinx, XC9572-PC44). Experimental results show the effectiveness of the proposed method.

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