• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1276-1282
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• 2002

In this paper, a high speed charging algorithm that charges Ni-Cd secondary pack battery within 40 minutes is implementation. Proposed algorithm is that suppling 4 stage pulse instead of constant voltage or current. That makes charge time short, temperature low, and extends battery life. Experimental results show that secondary pack battery is charged within 40 minutes and achieved life time about 2000 cycle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.5
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• pp.417-422
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• 2001

The needs of new materials that substitute Si Oxide capacitor layer in high density DRAM increase. So in this paper, we choose the slim region 14/50/50 PLZT composition and fabricated thin films by PLD and estimated the characteristics for DRAM application. 14/50/50 PLZT thin films have crystallized into perovskite structure in the $600^{\circ}C$ deposition temperature and 200 mTorr Oxygen pressure. In this condition, PLZT thin films had 985 dielectric constant, storage charge density 8.17 $\mu$C/$\textrm{cm}^2$ and charging time 0.20ns. Leakage Current density was less than 10$^{-10}$ A/$\textrm{cm}^2$ until 5V bias voltage.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2649-2652
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• 2002

In this paper, a high speed charging algorithm that charges secondary pack battery within 40 minutes is implementation. Proposed algorithm is that suppling 4 stage pulse instead of constant voltage or current. That makes charge time short, temperature low, and extends battery life. Experimental results show that secondary pack battery is charged within 40 minutes and achieved life time about 2000 cycle.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.253-259
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• 2002

The value of charge currnet, discharge current, ${\varepsilon}r^'$,${\varepsilon}r^{'}$ residual voltage was measured inorder to investigate electric properties in Ethylene Prophylene Rubber for is irradiated C0$^{60}$$\gamma$ ray 0~38.1 Mrad. The value of charge current and the discharging current of the EPR is influenced by C0$^{60}$-$\gamma$- irradiation dose. The charging current and the discharging current of EPR increas, depending on the ratio of degradation. As the irradiatin dose is increased, the peak of residual voltage moves to the slorter time. The properties specific electric constant due to time variation was appeared dispersion by plentiful C0$^{60}$$\gamma$- irradiation dose. The increase of peak in ${\varepsilon}r^{'}$ is attrib uted to the irratiation dose almost proportionally.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.476-477
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• 2018

최근 휴대폰 등 DC 가전기기의 증대와 에너지 시간 이동이 가능한 저장장치를 겸비한 스마트그리드 출현으로 에너지를 저장하는 장치의 수요가 증가하고 있다. 본 논문에서는 충전시간이 많이 소요되는 정전압 충전 방식을 제거하고 정전류 충전방식으로만 배터리 충전을 완료할 수 있는 충전기법을 제안한다. 이를 위해 정전류 충전에 필요한 배터리 파라미터를 실시간으로 추정하여 배터리 전압을 추정할 수 있는 간략화된 알고리즘을 제안한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.1
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• pp.84-90
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• 2013

This paper explains control methods of single-phase grid connected battery charger. Charging mode is control by Constant Current - Constant Voltage method and discharging mode is controlled by active-reactive power control method. Current control method is based on the synchronous reference frame(SRF) PI controller, and the second harmonic of battery current is compensated by an added L-C resonant circuit. Feasibility of the proposed control methods is verified through experiment with a prototype of 5kW single-phase grid connected battery charger.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.2
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• pp.186-192
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• 2012

Half-rail stacked drivers are used to reduce power consumption of the drivers for synchronous buck converters. In this paper, the stacked driver is optimized by matching the average charging and discharging currents used by high-side and low-side drivers. By matching the two currents, the average intermediate bias voltage can remain constant without the aid of the voltage regulator as long as the voltage ripple stays within the window defined by the hysteresis of the regulator. Thus the optimized driver in this paper can minimize the power consumption in the regulator. The current matching requirement yields the value for the intermediate bias voltage, which deviates from the half-rail voltage. Furthermore the required capacitance is also reduced in this design due to decreased charging current, which results in significantly reduced die area. The detailed analysis and design of the stacked driver is verified through simulations done using 5V MOSFET parameters of a typical 0.35-${\mu}m$ CMOS process. The difference in power loss between the conventional half-rail driver and the proposed driver is less than 1%. But the conventional half-rail driver has excess charge stored in the capacitor, which will be dissipated in the regulator unless reused by an external circuit. Due to the reduction in the required capacitance, the estimated saving in chip area is approximately 18.5% compared to the half-rail driver.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6006-6012
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• 2012

General solar street light system needs two separate power supply for charging the battery and driving LED Lamp. In this study, one power supply is used for both charging battery and driving LED lamp. In particular, in order to increase the efficiency of the equipment, (maximum power point tracking: MPPT) was applied which is widely adopted in grid-connected solar systems. LED driver embodied using current control routine of charger into Essential constant current system.

• Corrosion Science and Technology
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• v.16 no.6
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• pp.317-327
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• 2017

The change in the oxidation behavior of three types of B-added ultrahigh strength martensitic steels containing Ti and Nb induced by applying constant cathodic current was investigated. In a 3% NaCl+0.3% $NH_4SCN$ solution, the overall polarization behavior of the three alloys was similar, and degradation of the oxide film was observed in the three alloys after applying constant cathodic current. A significant increase in the anodic current density was observed in the Nb-added alloy, while it was diminished in the Ti-added alloy. Both Ti and Nb alloying decreased the hydrogen overpotential by forming NbC and TiC particles. In addition, the thickest oxide film was formed on the Ti-added alloy, but the addition of Nb decreased the film thickness. Therefore, it was concluded that the remarkable increase in the anodic current density of Nb-added alloy induced by applying constant cathodic current density was attributed to the formation of the thinnest oxide film less protective to hydrogen absorption, and the addition of Ti effectively blocked the hydrogen absorption by forming TiC particles and a relatively thick oxide film.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.8
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• pp.927-933
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• 2006

The structural and electrical characteristics of PLZT thin films fabricated onto $Pt/IrO_2/Ir/Ti/SiO_2/Si$ substrates by a pulsed laser deposition were investigated to develop the high dielectric thin films for capacitor layer of semiconductor memory devices The slim region 14/50/50 PLZT thin films were fabricated by PLD and estimated the characteristics for memory application 14/50/50 PLZT thin films have crystallize into perovskite structure at the $600^{\circ}C$ deposition temperature, 200 mTorr of oxygen pressure, and 2 $J/cm^2$ of laser energy density. In this condition PLZT thin films had the dielectric constant as high as 985, storage charge density 8.17 ${\mu}C/cm^2$ and charging time 0.20 ns. Leakage current density was less than $10^{-10}A/cm^2$ up to 5 V bias voltage.