• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.71-78
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• 2010

The existing capacitor-testers could only judge the condition of capacitor is normal or abnormal, and could not inform the real characteristics of the tested capacitors. In this research, it has designed the real-time observation of the new capacitor in charge and discharge tester for showing capacitor conditions and classification through wide voltages by regular cycle-tests. And proposed the quality classification algorithm of capacitors for more simple and practical, and approve them by test.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1555-1560
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• 2004

We made a simplified eddy-current-tester, and observed some materials for the ingredients and mass and locations. The tester detects the current as frequency shifts of a LC-resonance circuit, which are caused by the eddy currents. Using air-wick coil and a multi-piled ceramic capacitor, we made a resonance system whose frequency was 100KHz. The shift quantity is few; so, to detect it, we used a frequency counter, and counted the shift. We can detect 10Hz order's shift.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.85-87
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• 2020

고전압 커패시터는 회로 전체 안전성의 이유로 신뢰도를 유지하는 것이 매우 중요하다. 따라서 커패시터는 다양한 특성에 대해 시험이 필요하며 이때 장비가 필요하게 된다. 커패시터 시험용 특성으론 용량, 내전압, 전압 변화량, I_rms, I_peak가 있는데, 이 중 전류(I_rms, I_peak) 시험기의 경우 시중에 거의 없고, 매우 고가에 거래가 되고 있다. 이는 기존 전류 시험기가 CCCV(constant current constant voltage) 충/방전 회로를 사용하여 높은 전력을 공급하는 Power Supply가 요구되기 때문이다. 본 논문은 상기 기존 기술의 문제점을 해결하고자 공진회로를 이용하여 새로운 커패시터 전류 시험기를 설계하였고, Simulation을 통해 제안 전류 시험기의 가능성을 검토하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.16-22
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• 2012

With the increase of consumption of new renewable energy, the use of Electric Double Layer Capacitor(EDLC) is being gradually widened as the next generation energy storage device. In order to expand the market of EDLC which is recently receiving a lot of attraction as a new promising area, development of a charge/discharge cycle tester to measure and test performance, is essential. Therefore, this research designed a circuit to measure capacity and internal resistance and a circuit to measure voltage maintenance properties, based on EDLC's basic charging/discharging properties so it is able to measure the state of charge and discharge at high speed. When evaluating performance characteristics, the 5[V]/100[A] prototype-EDLC charge/discharge testing system developed for this research showed ${\pm}0.1$[%] of accuracy of voltage and current measurement. It was also proved that the developed charge/discharge testing system for EDLC can be applied to the actual industry, when testing the entire system using a program produced for data monitoring and acquisition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.190-190
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• 2009

전자산업에의 필수인 커패시터는 소형화, 저저항, 고전압을 향한 추세가 늘고 있으며, 이외에도 고전압 전원, 고전압 회로 등 중전기기에 필요한 고전압, 고용량 커패시터가 사용되고 있다. 중전기기에 사용되는 커패시터는 기기에 따라 틀리지만 내전압이 보통 10kV 이상이고 정전용량이 500pF 안팎이며, 대부분 외국에서 수입에 의존하고 있는 실정이다. 본 연구에서는 $Nb_2O_5$를 2mol% 첨가한 $BaTiO_3$를 일반적인 고상 소결법으로 제조하고 성형 시 crack을 방지하기 위해 binder 및 plasticizer를 사용하였으며, binder 첨가량에 따른 성형밀도를 측정하여 최적의 binder양을 선택하였다. 성형 밀도가 떨어짐에 따라 절연파괴강도가 낮아지기 때문에 성형 밀도를 높이기 위해 CIP를 하였으며, 소결후 capacitance와 d-factor를 측정하여 수치가 허용 범위에 들어 올 경우 전극을 형성하고 표면파괴를 방지하기 위하여 epoxy로 표면코팅을 하였다. DC 60kV용 Hi-pot tester를 사용하여 15kV까지 선형적으로 증가시켜 내전압 테스트를 실시하였으며, 제조 된 커패시터 중 몇 개의 sample을 SEM 및 XRD를 사용하여 미세구조와 결정상을 조사하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.222-227
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• 2004

The sub-bitline (SBL) sensing voltage of a cell and total cell array can be measured by the method of SBL voltage evaluation method. The MOSAID tester can collect all SBL signals. The hierarchical bitline of unit cell array block is composed of the cell array of 2k rows and 128 columns, which is divided into 32 cell array sections. The unit cell array section is composed of the cell array of 64 rows and 128 columns. The average sensing voltage with 2Pr value of $5{\mu}C/cm^2$ and SBL capacitance of 40fF is about 700mV at 3.0V operation voltage. That is high compensation method for capacitor size degradation effect. Thus allowed minimum 2Pr value for high density Ferroelectric RAM (FeRAM) can move down to about less than $5{\mu}C/cm^2$.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.475-481
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• 2005

In the existing ICT technique, the mounted electronic devices on the printed circuit board are tested whether the devices are good or not by comparing and measuring the value of the devices after separating the devices to be tested from around it based on the guarding method. But, in case that resistance, inductor and capacitor are configured as a parallel circuit on the circuit pattern, values for each device can not be measured because the total impedance value of the parallel circuit is measured. Accordingly, it is impossible to test whether the parallel circuit is good or not in case that the measured impedance value is within the tolerance error. Also, it is difficult to identify that which device among R, L and C of the parallel circuit is bad in case that the measured impedance value is out of the tolerance error. Accordingly, this paper proposes a test method which can enhance the quality and productivity by separating and measuring accurately R, L and C components from the RLC parallel circuits on the device-mounted printed circuit board. First, the RLC parallel circuit to be test is separated electrically from around it using three-terminal guarding technique. And then R, L and C values are computed based on the total impedance values and phase angles between voltage and current of the parallel circuit measured from two AC input signals with other frequency, Finally, the availability and accuracy of the proposed test method is verified by reviewing the simulation results.

• Journal of Electrochemical Science and Technology
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• v.14 no.2
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• pp.184-193
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• 2023

This study investigates the effects of a carbon fiber layer formed on the surface of an etched aluminum current collector on the electrochemical properties of the activated carbon electrodes for an electric double layer capacitor. A particle size analyzer, field-emission SEM, and nitrogen adsorption/desorption isotherm analyzer are employed to analyze the structure of the carbon fiber layer. The electric and electrochemical properties of the activated carbon electrodes using a carbon fiber layer are evaluated using an electrode resistance meter and a charge-discharge tester, respectively. To uniformly coat the surface with carbon fiber, we applied a planetary mill process, adjusted the particle size, and prepared the carbon paste by dispersing in a binder. Subsequently, the carbon paste was coated on the surface of the etched aluminum current collector to form the carbon under layer, after which an activated carbon slurry was coated to form the electrodes. Based on the results, the interface resistance of the EDLC cell made of the current collector with the carbon fiber layer was reduced compared to the cell using the pristine current collector. The interfacial resistance decreased from 0.0143 Ω·cm² to a maximum of 0.0077 Ω·cm². And degradation reactions of the activated carbon electrodes are suppressed in the 3.3 V floating test. We infer that it is because the improved electric network of the carbon fiber layer coated on the current collector surface enhanced the electron collection and interfacial diffusion while protecting the surface of the cathode etched aluminum; thereby suppressing the formation of Al-F compounds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.239-245
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• 2016

In this study, a 12 V PWM boost converter was designed with the optimal values of the external components of the power stage was well as the compensation stage for smart electronic applications powered by a battery device. The 12 V boost PWM converter consisted of several passive elements, such as a resistor, inductor and capacitor with a diode, power MOS switch and control IC chip for the control PWM signal. The devices of the power stage and compensation stage were designed to maintain stable operation under a range of load conditions as well as achieving the highest power efficiency. The results of this study were first verified by a simulation in SPICE from calculations of the values of major external elements comprising the converter. The design was also implemented on the prototype PCBboard using commercial IC LM3481 from Texas Instruments, which has a nominal output voltage of 12 V. The output voltage, ripple voltage, and load regulation with the line regulation were measured using a digital oscilloscope, DMM tester, and DC power supply. By configuring the converter under the same conditions as in the circuit simulation, the experimental results matched the simulation results.

• Journal of Sensor Science and Technology
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• v.14 no.1
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• pp.33-41
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• 2005

For more convenient electrode-electrolyte interface impedance analysis in biosensor, a stand-alone impedance measurement system is required. In our study, we developed a PC-based portable system to analyze impedance of the electrochemical cell using microprocessor. The devised system consists of signal generator, programmable amplifiers, A/D converter, low pass filter, potentiostat, I/V converter, microprocessor, and PC interface. As a microprocessor, PIC16F877 which has the processing speed of 5 MIPS was used. For data acquisition, the sampling rate at 40 k samples/sec, resolution of 12 bit is used. RS-232 with 115.2 kbps speed is used for the PC communication. The square wave was used as stimuli signal for impedance analysis and voltage-controlled current measurement method of three-electrode-method were adopted. Acquired voltage and current data are calculated to multifrequency impedance signal after Fourier transform. To evaluate the implemented system, we set up the dummy cell as equivalent circuit of which was composed of resistor, parallel circuit of capacitor and resistor connected in parallel and measured the impedance of the dummy cell; the result showed that there exist accuracy within 5 % errors and reproduction within 1 % errors compared to output of Hioki LCR tester and HP impedance analyzer as a standard product. These results imply that it is possible to analyze electrode-electrolyte interface impedance quantitatively in biosensor and to implement the more portable high speed impedance analysis system compared to existing systems.