• Journal of IKEEE
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• v.11 no.4
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• pp.315-321
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• 2007

The fast charging photoflash capacitor charger with wide range current limiter is presented. By using proposed control logic block and wide range current limiter, the photoflash capacitor charger can reduce charging time and control life of battery for user convenience. The proposed photoflash capacitor charger has 3s charging time at 3.3V battery voltage, 1.2A current limit condition. It is well-suited for portable device application like digital camera, digital video camera, and mobile phone with camera.

• Journal of the Korean Society for Railway
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• v.8 no.3
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• pp.235-243
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• 2005

Following the rail reform in 2004, rail industry in Korea has separated into two parts: one is the infrastructure manager and the other is train operator. Amongst many aspects, track access charging system is one of the imminent aspects to be studied closely to make the rail reform successful. In this study, track access charging systems of European countries are closely investigated and compared one another and lessons learnt from their experiences are derived. Finally, policy directions regarding the track access charging system to be adopted in Korea are suggested.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.26-32
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• 2020

In this study, the side reactions that greatly affect the coulombic efficiency of a zinc-air secondary battery are quantitatively analyzed on the basis of the charging-discharging characteristics, open circuit self-discharge characteristics, and a series of calculations. In particular, the charge amounts consumed by water electrolysis and self-discharge during charging process are separately determined so that the charging efficiency (the amount of charge used in actual charging with respect to the applied charge amount) can be estimated, which would enable systematic understanding of the cause of coulombic efficiency degradation. Using two cells with different charging overvoltages, the validity of the proposed method can be assessed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.394-400
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• 2012

In this paper, charging modes of series resonant converter for a high voltage energy storage capacitor are compared in terms of charging time, peak resonant current, normalized peak resonant current and voltage in each operation mode. Operating principles of the full bridge series resonant converter with capacitor load are explained and analyzed in discontinuous and continuous operation mode. Based on the analysis and simulation result, $0.6{\omega}_r$ < ${\omega}_s$ < $0.75{\omega}_r$ and $1.3{\omega}_r$ < ${\omega}_s$ < $1.4{\omega}_r$ are evaluated to the best range of switching frequency for charging of an high voltage energy storage capacitor. 1.8 kJ/s SRC prototype is assembled with TI 28335 DSP controller and 40 kJ, 7 kV energy storage capacitor. Design rules based on the comparative analysis are verified by experiment.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.213-214
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• 2001

This paper describes a power supply for a rapid pulse power charging system designed for charging a $0.35{\mu}F$ capacitor to 20kV in approximately 3ms. The power supply should be capable of recharging the load capacitor maximum 300 times within one second. This power supply is based on a series resonant 3-phase inverter followed by the step-up transformers. The experiments have been carried out at different repetition rates and charging voltages.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.10
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• pp.828-834
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• 2003

A diffusion absorption refrigerator is a heat-generated refrigeration system. It uses a three-component working fluid consisting of the refrigerant (ammonia), the absorbent (water) and the auxiliary gas (hydrogen or helium). In this study, experimental investigations have been carried out to examine the effects of charging conditions of working fluids on the evaporating temperature for diffusion absorption refrigerator. Experimental parameters considered in the present experiments are charging concentration, solution charge and system pressure determined by auxiliary gas charged. As a result, in the charging condition of 35% of concentration and 20 kg$_{f}$cm$^2$ of system pressure, the system has the lowest evaporating temperature. It was found that there exists a minimum value of solution charge for the operation of diffusion absorption refrigerator.r.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.516-517
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• 2008

The ethylene-propylene (EP) rubbers mixed with one to one ratio is used as an insulation material in the nuclear power plant. It was investigated the effect of the amount of reinforcing agent. moisture absorption and heat treatment on the Ethylene-Propylene(EP) rubbers. The level of degradation was measured by the amount of discharging and. charging currents. When $\gamma$ rays were radiated on the EP rubbers with more charging material, the amount of discharging and charging currents was depended on the amount of reinforcing agent It was verified that the discharging and charging currents irradiated by $\gamma$ rays were higher than those that was not irradiated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.124-130
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• 2011

In this paper, We design and implementation of Self-Charging Module for charging to battery which obtaining the environment inergy such as solar energy. The power chared battery through the charging module send to sensor node. And implementation of System Activation Module(SAM) based on ID system and Dynamic Power Management Module(DPM) with SPO(Self Power Off). This system consume power only communication between the sensor nodes. We verification this system by implementing the high efficiency poweer management system.

• Journal of Aerospace System Engineering
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• v.8 no.4
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• pp.32-38
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• 2014

Sufficient energy charging during a day is essential for a solar-powered long-endurance aircraft. Variations of flight path that is superior to a basic circle path are sought in this study for more efficient charging. Flight path associated with roll and pitch attitudes are investigated. It seems that the pitch angle can play more important role than the roll angle for the solar charging efficiency. Thus, more energy charging is observed when the entire flight path is tilted toward the direction of the sun.

• Journal of Power Electronics
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• v.16 no.1
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• pp.268-276
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• 2016

A hybrid sinusoidal-pulse current (HSPC) charging method for the Li-ion batteries in electric vehicle applications is proposed in this paper. The HSPC charging method is based on the Li-ion battery ac-impedance spectrum analysis, while taking into account the high power requirement and system integration. The proposed HSPC method overcomes the power limitation in the sinusoidal ripple current (SRC) charging method. The charger shares the power devices in the motor inverter for hardware cost saving. Phase shifting in multiple pulse currents is employed to generate a high frequency multilevel charging current. Simulation and experimental results show that the proposed HSPC method improves the charger efficiency related to the hardware and the battery energy transfer efficiency.