• Title/Summary/Keyword: External capacitor

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Development of a Microplasma Source under Atmospheric Pressure using an External Ballast Capacitor (방전에너지 제어용 외부 커패시터를 이용한 대기압 마이크로 플라즈마 소스 개발)

  • Ha, Chang-Seung;Lee, Je-Hyun;Son, Eui-Jeong;Park, Cha-Soo;Lee, Ho-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.6
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    • pp.31-38
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    • 2013
  • A pulse driven atmospheric plasma jet controlled by external ballast capacitor is developed. Unlike the most commonly use DBD sources, the proposed device utilizes bare metal electrode. The discharge energy per pulse can precisely be determined by changing voltage and capacitance of the ballast capacitor. It is shown that the device can provide wide range of plasma, from stable glow mode to near arc state. Current-voltage waveforms, optical emission spectra and discharge images are investigated as a function of an injection energy. The OES shows that He and oxygen lines are increased as a function of the external ballast capacitor. Ozone and rotational temperature have similar tendency with a power consumption. The feeding gas is He and the applied DC voltage is from 400V to 800V when the gap distance is $500{\mu}m$.

External Ballast Capacitor를 이용한 대기압 플라즈마 개발 및 분석

  • Ha, Chang-Seung;Son, Ji-Han;Kim, Dong-Hyeon;Lee, Ho-Jun;Lee, Hae-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.491-491
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    • 2012
  • External ballast capacitor를 이용하여 방전에너지를 제어하는 대기압 플라즈마 발생장치를 개발하였다. 기존은 대부분의 대기압 플라즈마 발생장치는 DBD를 이용하여 방전전류를 제어하였으나, 본 연구에서는 유전체를 없이 두 금속전극 사이에서 플라즈마를 발생시켰다. 외부에 연결된 External ballast capacitor에서 방전에너지가 전극 쪽으로 주입되도록 하였다. 따라서 capacitor의 용량과 인가전압에 따라 플라즈마의 방전에너지를 제어할 수 있다. 본 연구에서는 Optical Emission Spectroscopy와 ICCD Camera를 통하여 개발된 플라즈마 발생장치의 온도특성, 밀도와 같은 광학적 특성을 관찰하였으며, 아울러 전기적 특성도 함께 관찰하였다. 이 논문은 2011년도 정부(교육과학기술부)의 재원으로 한국연구재단의 기초연구사업 지원을 받아 수행된 것임(2011-0004827).

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The Explosion Prevention Method for Electrolytic Motor Start Capacitors using Current Characteristic (통전전류 특성을 이용한 모터 기동용 전해 커패시터 폭발 방지 방법)

  • Kim, Jae-Hyun;Park, Jin-Young;Park, Kwang-Muk;Bang, Sun-Bae;Kim, Yong-Un
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.12
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    • pp.1836-1843
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    • 2017
  • In this paper, we investigated fire cases those are believed to be caused by explosion of a electrolytic motor start capacitor. Using two types of commercially available electrolytic motor start capacitors, capacitor current and the possibility of capacitor explosion were tested. And the ignition possibility of the internal material leaked from a capacitor was also tested. In addition, experiments were conducted to see if the fire could spread when a capacitor was exposed to an external flame. From our test we observed that the current of the electrolytic motor start capacitor rose continuously to a certain level by product, if the capacitor was continuously energized with working voltage, and then the capacitor was exploded. The gas and liquid leaked from the capacitor by the explosion could ignite by an electric arc and an external flame. The capacitor current at explosion was different product by product, but each product had a certain current level at explosion. And the increase rate of the capacitor current until explosion was 24% and 31% for the products used in the experiment. We proposed the capacitor explosion prevention method that cuts off power when the capacitor current rises to a certain threshold level. The proposed method can be used if the current of the applied electrolytic motor start capacitor rises continuously and then the capacitor is exploded at a certain current level when the capacitor is energized continuously.

EEPROM Charge Sensors (EEPROM을 이용한 전하센서)

  • Lee, Dong-Kyu;Jin, Hai-Feng;Yang, Byung-Do;Kim, Young-Suk;Lee, Hyung-Gyoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.8
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    • pp.605-610
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    • 2010
  • The devices based on electrically erasable programmable read-only memory (EEPROM) structure are proposed for the detection of external electric charges. A large size charge contact window (CCW) extended from the floating gate is employed to immobilize external charges, and a control gate with stacked metal-insulator-metal (MIM) capacitor is adapted for a standard single polysilicon CMOS process. When positive voltage is applied to the capacitor of CCW of an n-channel EEPROM, the drain current increases due to the negative shift of its threshold voltage. Also when a pre-charged external capacitor is directly connected to the floating gate metal of CCW, the positive charges of the external capacitor make the drain current increase for n-channel, whereas the negative charges cause it to decrease. For an p-channel, however, the opposite behaviors are observed by the external voltage and charges. With the attachment of external charges to the CCW of EEPROM inverter, the characteristic inverter voltage behavior shifts from the reference curve dependent on external charge polarity. Therefore, we have demonstrated that the EEPROM inverter is capable of detecting external immobilized charges on the floating gate. and these devices are applicable to sensing the pH's or biomolecular reactions.

Coordination of SVC and External Reactor/Capacitor Banks Using Multi-objective (다목적 유전자 알고리즘을 이용한 SVC와 외부 리액터/커패시터 뱅크의 헙조 제어)

  • Park, Jong-Young;Lee, Sang-Ho;Park, Jong-Keun;Son, Kwang-Myoung;Lee, Song-Keun
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.233-235
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    • 2000
  • SVC(Static Var Compensator) is commonly installed with conventional mechanically switched existing reactor or capacitor banks for wide range voltage control. The frequencies of switching of external banks have a great impact on the quality of voltage, but is limited since the life time of the external banks depends severely on the number of switching. So it is a complete multi-objective nonlinear optimization problem with conflicting objectives. This paper presents a method to determine the optimal coordination of SVC and external banks using genetic algorithm based on the multi-objective criteria. Optimal dead band and delay time of external banks is sought for reliable and efficient operation

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The Method to Improve the Luminance Efficiency by Auxiliary Capacitor in AC PDP

  • Lee, Ji-Hoon;Lee, Don-Kyu;Choi, Joon-Young;Ok, Jung-Woo;Kim, Dong-Hyun;Lee, Ho-Jun;Park, Chung-Hoo;Lee, Hae-June
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.913-916
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    • 2006
  • The improvement of luminous efficacy is one of the major issues in PDP industry. In this work, we propose the new driving method for high efficiency AC-PDP and analyze its discharge characteristics. The suggested method can control the effective capacitance of panel by external auxiliary capacitor. External capacitor induces reduction of gap voltage proportional to the panel current, this in turn modifies the transient behaviour of discharge. The peak current level is reduced and the discharge duration is increased. As a result of these modifications, the luminous efficacy is enhanced by about 200% compared with the conventional driving method

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External Ballast Capacitor를 통해 발생된 아크 방전의 특성 분석

  • Son, Ji-Han;Ha, Chang-Seung;Kim, Dong-Hyeon;Lee, Hae-Jun;Lee, Ho-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.490-490
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    • 2012
  • Ballast capacitor에 저장된 에너지로 방전 에너지를 조절할 수 있는 방전장치를 개발하였다. 본 연구에서는 ballast capacitor의 용량을 조절하여 micro-size의 아크 플라즈마를 발생시켰으며, 용량변화에 따른 플라즈마의 온도를 측정하였다. 또한 ICCD camera를 이용하여 ballast capacitor의 용량변화에 따른 cathode의 변화를 관찰하였다. Optical Emission Spectroscopy를 통하여 플라즈마의 광학적 특성을 분석하였다. 마이크로 아크 방전의 주파수를 높이기 위하여 switching device를 병렬로 연결하여 아크 플라즈마를 구동시켰으며, 발생된 마이크로 아크 플라즈마는 정밀방전 가공에 응용되었다. 본 연구는 2011년도 지식경제부의 재원으로 한국에너지 기술평가원(KETEP)의 지원을 받아 수행한 연구 과제입니다(No. 20104010100670).

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Implementation of One-Cycle Control for Switched Capacitor Converters

  • Yang, Lei;Zhang, Xiaobin;Li, Guann-pyng
    • Journal of Power Electronics
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    • v.16 no.6
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    • pp.2057-2066
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    • 2016
  • An extension of the one-cycle control (OCC) method for switched-capacitor (SC) converters is proposed in this paper, featuring a fast dynamic response, wide line and load operation ranges, and simplicity in implementation. To illustrate the operation principle of this nonlinear control method and to demonstrate its simplicity in design, a dual-phase unity gain SC converter is examined. A new control loop based on the charge balance in a flying capacitor is formulated for the OCC technique and implemented with a 15W dual-phase unity gain SC converter on a circuit board for control verification. The obtained experimental results show that external disturbances can be rejected in one switching cycle by the OCC controlled SC converter with good line and load regulations. When compared to other control methods, the proposed nonlinear control loop exhibits superior dynamic performance in suppressing input and load disturbances.

Characteristic Investigation of External Parameters for Fault Diagnosis Reference Model Input of DC Electrolytic Capacitor (DC 전해 커패시터의 고장진단 기준모델 입력을 위한 외부변수의 특성 고찰)

  • Park, Jong-Chan;Shon, Jin-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.4
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    • pp.186-191
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    • 2012
  • DC Bus Electrolytic capacitors have been widely used in power conversion system because they can achieve high capacitance and voltage ratings with volumetric efficiency and low cost. This type of capacitors have been traditionally used for filtering, voltage smoothing, by-pass and other many applications in power conversion circuits requiring a cost effective and volumetric efficiency components. Unfortunately, electrolytic capacitors are some of the weakest components in power electronic converter. Many papers have proposed different methods or algorithms to determinate the ESR and/or capacitance C for fault diagnosis of the electrolytic capacitor. However, both ESR and C vary with frequency and temperature. Accurate knowledge of both values at the capacitors operating conditions is essential to achieve the best reference data of fault judgement. According to parameter analysis, the capacitance increases with temperature and the ESR decreases. Higher frequencies make the ESR and C to decrease. Analysis results show that the proposed electrolytic capacitor parameter estimation technique can be applied to reference signal of capacitor diagnosis systems successfully.

BST Thin Film Multi-Layer Capacitors

  • Choi, Woo Sung;Kang, Min-Gyu;Ju, Byeong-Kwon;Yoon, Seok-Jin;Kang, Chong-Yun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.319-319
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    • 2013
  • Even though the fabrication methods of metal oxide based thin film capacitor have been well established such as RF sputtering, Sol-gel, metal organic chemical vapor deposition (MOCVD), ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD), an applicable capacitor of printed circuit board (PCB) has not realized yet by these methods. Barium Strontium Titanate (BST) and other high-k ceramic oxides are important materials used in integrated passive devices, multi-chip modules (MCM), high-density interconnect, and chip-scale packaging. Thin film multi-layer technology is strongly demanded for having high capacitance (120 nF/$mm^2$). In this study, we suggest novel multi-layer thin film capacitor design and fabrication technology utilized by plasma assisted deposition and photolithography processes. Ba0.6Sr0.4TiO3 (BST) was used for the dielectric material since it has high dielectric constant and low dielectric loss. 5-layered BST and Pt thin films with multi-layer sandwich structures were formed on Pt/Ti/$SiO_2$/Si substrate by RF-magnetron sputtering and DC-sputtering. Pt electrodes and BST layers were patterned to reveal internal electrodes by photolithography. SiO2 passivation layer was deposited by plasma-enhanced chemical vapor deposition (PE-CVD). The passivation layer plays an important role to prevent short connection between the electrodes. It was patterned to create holes for the connection between internal electrodes and external electrodes by reactive-ion etching (RIE). External contact pads were formed by Pt electrodes. The microstructure and dielectric characteristics of the capacitors were investigated by scanning electron microscopy (SEM) and impedance analyzer, respectively. In conclusion, the 0402 sized thin film multi-layer capacitors have been demonstrated, which have capacitance of 10 nF. They are expected to be used for decoupling purpose and have been fabricated with high yield.

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