• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.576-579
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• 2009

This paper suggests a autonomous linear Li-ion battery charger which can safely distribute power between an external power source(AC adapter, auto adapter, or USB source), battery, and the system load. Depending on an external power source's capability, the charger selects proper charging-mode automatically. The charger IC designed and fabricated on Dongbu HITEC's $0.35{\mu}m$ BCD process with layers of one poly and three metals.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1848-1850
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• 1996

A Couette Charger was used to simulate streaming electrification process in transformer. This paper describes the electrification characteristics of the energized and unenergized Couette Charger. By applying low frequency and high voltage across the cylinder of the Couette Charger, the measured short circuit current$i_{sc}$) is compared with the measured values of unenergized Couette Charger. As a result, short circuit current was increased with voltage.

• Journal of the Korea Convergence Society
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• v.4 no.1
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• pp.27-31
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• 2013

The fast-paced development in the field of wireless charger based on M2M, which is available anytime and anywhere, is being underway in accordance with the development of IT technology. Wireless charger technology in M2M has various security threats because it is based on wireless network. The purpose of this paper is to examine the threats of authentication and payment attacks based on wireless network attacks, and to propose the response technique that fit the situation of the wireless charger service by modifying the existing detecting authentication and payment through wireless charger.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.534-535
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• 2014

This paper proposes parallel operation of multi function rapid-charger with an active power filter. Rapid-charger can be installed in public institutions or mart parking lot. But conventional charger has disadvantage that it can not be used as the active power filter in charging mode with only one charger. So using 3-parallel operation, effective mode transfer between battery charging and APF function can obtain effect of harmonic compensation and improving the utilization of the charger.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.539-548
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• 2007

In the paper, a wireless charger with the function of auto-shutdown for fully implantale middle ear hearing devices (F-IMEHD) has been designed. The wireless charger can communicate with an implant module to be turned off automatically shutdown after an internal rechargeable battery has been fully-charged by electromagnetic coupling using two coils. For the communication with an implant module, the wireless charger uses the load shift keying (LSK) method. But, the variation of the mutual inductance due to the different distance between two coils can cause the communication error in receiving the fully-charged signal from an implant module. To solve the problem, the implemented wireless charger has a variable reference generator for LSK communication. The wireless charger generates proper level of the reference voltage for a comparator using an ADC (analog-to-digital converter) and a DAC (digital-to-analog converter). Through the result of experiment, it has been confirmed that the presented wireless charger can detect signals from implantable module. And wireless charger can stop generating electromagnetic flux after an implanted battery has been fully charged in spite of variable coil distance according to different skin thickness.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.3
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• pp.315-323
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• 2004

An electrical cascade impactor is a multi-stage impaction device to separate airborne particles into aerodynamic size classes using particle charging and electrical detection techniques. A Faraday cage and an aerosol charger, which are basic components of the electrical cascade impactor, were designed and evaluated in this study. The low-level current response of the Faraday cage was investigated with changing particle size and air flow rate by using sodium chloride (NaCl) particles. The response of the prototype Faraday cage was very similar to that of a commercial aerosol electrometer (TSI model 3068) within ${\pm}$5% for singly-charged particles. The response linearity of the prototype Faraday cage could be extended up to flow rate of 30 L/min. For the performance evaluation of the aerosol charger the monodisperse liquid dioctyl sebacate (DOS) particles, with diameters of 0.1∼0.8$\mu\textrm{m}$, were generated using spraying from an atomizer followed by evaporation-condensation process. Typical performance parameters of the aerosol charger such as P$.$n, wall loss, and elementary charges per particle were evaluated. The performance of the prototype aerosol charger was found to be close to that of the aerosol charger used in an electrical low pressure impactor (ELPI, Dekati).

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.520-527
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• 2006

The electrical discharge and operational characteristics of needle and wire-cylinder corona charger based on current measurements for positive and negative coronas were evaluated and compared. A semi-empirical method was used to determine the ion concentrations in the charging zone and at the outlet of both chargers. Results from experimental investigation revealed that magnitudes of the charging current from the wire-cylinder charger were approximately 3.5 and 2 times smaller than those from the needle charger for the positive and negative coronas, respectively. The ion number concentrations at the outlet for positive corona of both chargers were higher than fur negative corona at the same voltage. Flow and electric fields in the charging zone of both chargers were also analyzed via numerical computation. Strong electric field strength zone was identified and led to high charging and particle deposition. Effect of particle deposition on the evolution of discharge current was presented. It was shown that ions loss inside the wire-cylinder charger was higher than the needle charger The particle deposited on the corona electrodes and on the grounded cylinder caused a great reduction in charging efficiency of both chargers.

• Journal of Power Electronics
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• v.15 no.1
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• pp.31-38
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• 2015

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.4
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• pp.277-284
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• 2021

A single and three phase-compatible single-stage EV charger without electrolytic capacitor is proposed in this study. DC battery-charging current is inherently guaranteed in the three-phase grid due to three output currents with a phase shift of 120° between each other. The proposed EV charger can provide a DC battery charging current for the single-phase grid through the integrated active power decoupling circuit without using additional switches. The proposed EV charger ensures ZVS turn-on of all switches with wide grid and battery voltage ranges. The 11 kW prototype of the proposed EV charger demonstrates a peak efficiency of 97.01% and a power density of 5.58 kW/L.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.636-640
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• 2000

A novel integrated battery charger/discharger converter for a standardized battery module is proposed. Instead of using separate charger and discharger converters. it integrates these two converters into a single converter in order to minimize the size. the integrated charger/discharger converter not only regulates the solar array output power including the peak power tracking capability but also controls the battery charging/discharging current depending on the solar array output power and the load power. In addition it offers a regulated bus voltage which simplifies the power distribution/conversion for the pay load.