• KEPCO Journal on Electric Power and Energy
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• 제6권4호
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• pp.405-411
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• 2020

In this paper, we designed the COS MEMS system for sensing the falling detection and explosive noise of fuse link in COS (Cut Out Switch) installing on the power distribution. This system analyzed the failure characteristics and an instantaneous breakdown of power distribution. Therefore, our system strengths the industrial competence and guaranties the stable power supply. In this paper, we applied BLE (Bluetooth Low Energy) technology which is suitable protocol for low data rate, low power consumption and low-cost sensor applications. We experimented with LSM6DSOX which is system-in-module featuring 3 axis digital accelerometer and gyroscope boosting in high-performance mode and enabling always-on low-power features for an optimal motion for the COS fuse holder. Also, we used the MP34DT05-A for gathering an ultra-compact, low power, omnidirectional, digital MEMS microphone built with a capacitive sensing element and an IC interface. The proposed COS MEMS system is developed based on nRF52 SoC (System on Chip), and contained a 3-axis digital accelerometer, a digital microphone, and a SD card. In this paper of experiment steps, we analyzed the performance of COS MEMS system with gathering the accelerometer raw data and the PDM (Pulse Data Modulation) data of MEMS microphone for broadcasting the failure of COS status.

• Journal of Power Electronics
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• 제15권5호
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• pp.1305-1317
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• 2015

Distributed generation systems (DGSs) have been getting more and more attention in terms of renewable energy use and new generation technologies in the past decades. The self-excited induction generator (SEIG) occupies an important role in the area of energy conversion due to its low cost, robustness and simple control. Unlike synchronous generators, the SEIG has to absorb capacitive reactive power from the outer device aiming to stabilize the terminal voltage at load changes. This paper presents a novel static VAR compensator (SVC) called a magnetic energy recovery switch (MERS) to serve as a voltage controller in SEIG powered DGSs. In addition, many small scale SEIGs, instead of a single large one, are applied and devoted to promote the generation efficiency. To begin with, an expandable mathematic model based on a d-q equivalent circuit is created for parallel SEIGs. The control method of the MERS is further improved with the objective of broadening its operating range and restraining current harmonics by parameter optimization. A hybrid control strategy is developed by taking both of the stand-alone and grid-connected modes into consideration. Then simulation and experiments are carried out in the case of single and double SEIG(s) generation. Finally, the measurement results verify that the proposed DGS with SVC-MERS achieves a better stability and higher feasibility. The major advantages of the mentioned variable reactive power supplier, when compared to the STATCOM, include the adoption of a small DC capacitor, line frequency switching, simple control and less loss.

• 전기학회논문지
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• 제59권4호
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• pp.762-767
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• 2010

This paper describes characteristic of a light triggered thyristor investigated by experiment to adopt it into a main switch of a pulsed power unit. Triggering principle of the light triggered thyristor are referred with its structure and equivalent circuit. Operational principle and simulation result of a capacitive pulsed power circuit are explained. A variety of triggering conditions of triggering circuit and characteristics on turn-on, turn-off, voltage dividing in series operation, overvoltage protection function of the light triggered thyristor are investigated by experiments. Experimental result of 40 kJ pulsed power unit using the light triggered thyristor is presented.

• 전자공학회논문지A
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• 제33A권6호
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• pp.206-219
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• 1996

This paper describes a data structure and evaluation algorithm to improve the perofmrances MOS logic-with-timing simulation in computation and accuracy. In order to efficiently simulate the logic and timing of driver-load networks, (1) a tree data structure to represent the mutual interconnection topology of switches and nodes in the driver-lod network, and (2) an algebraic modeling to efficiently deal with the new represetnation, (3) an evaluation algorithm to compute the linear resistive and capacitive behavior with the new modeling of driver-load networks are developed. The higher modeling presented here supports the structural and functional compatibility with the linear switch-level to simulate the logic-with-timing of digital MOS circuits at a mixed-level. This research attempts to integrate the new approach into the existing simulator RSIM, which yield a mixed-klevel logic-with-timing simulator MIXIM. The experimental results show that (1) MIXIM is a far superior to RSIM in computation speed and timing accuracy; and notably (2) th etiming simulation for driver-load netowrks produces the accuracy ranged within 17% with respect ot the analog simulator SPICE.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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• pp.178-183
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• 2002

In this paper, the capacitive sensor which can detect the continuous position of liquid is proposed. The proposed sensor make up copper rod's defect which are oxidized in liquid and float switch's defect which are tired of continuous movements. This sensor make use of what capacitance is varying due to quantity and kind of dielectric in the plane gap. The operating principle of the sensor and the amplifying methode of detecting signal and the methode of apply in computer control system are presented in this paper.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.501-507
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• 2014

This paper describes the improvement in converter efficiency by reducing the switching loss and by recovering the snubber stored energy. A capacitive based passive regenerative snubber circuit is modeled for a dc-dc boost converter. The proposed snubber is mainly used to reduce the turn-off loss of the main switch. The energy recovery process and the turn-off loss depends on the size of the snubber capacitance; therefore, the conventional and the proposed converters are designed for high and low input voltage conditions with different sizes of the snubber capacitance. Based on the results obtained, the snubber capacitors are classified as small, normal and large snubbers. The Matlab simulation results obtained are presented.

• 전자공학회논문지SC
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• 제40권1호
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• pp.39-44
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• 2003

휴대용 전자기기가 많이 개발되고 보급됨에 따라서 배터리의 중요성은 점점 커져가고 있다. 기기의 수명을 늘이고자 고전력밀도의 배터리를 요구하게 되었고, 현재에는 리튬-이온 배터리를 많이 사용하게 되었다. 단위체적 및 중량당의 전력밀도 부분에서는 기존에 사용하던 배터리보다 성능이 우수하지만, 방전전압이 감소하는 특성이 있기 때문에 배터리의 수명을 최대한 늘리기 위해서는 이 특성에 알맞은 컨버터가 필요하다. 그래서 리튬-이온 배터리를 사용하는 휴대용 저전력 전자기기의 전원부로써 용량성 아이들링 SEPIC을 제안하였다. 승압과 강압이 가능한 SEPIC의 특성을 가지면서, 추가된 스위치와 다이오드를 통해서 스위치에 부분적인 소프트 전환을 가능하게 하기 때문에, 스위칭 주파수의 증가를 가능하게 한다. 본 논문에서는 직류 정상상태의 전압전환비, 동작모드별 회로 및 회의특성을 분석하고 구현하였다.

• 패션비즈니스
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• 제24권5호
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• pp.140-157
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• 2020

The purpose of this study is to develop three functions for smartphones and PCs using a textile touch sensor in an everyday sports jacket and to present their usefulness; to this end, we have developed a mutual capacitive textile touch sensor and corresponding structure, and we have implemented three functions into a textile touch sensor jacket, of which we also conducted a usability evaluation. The jacket has a sensor on the wrist of the left sleeve and a device on the left arm. The sensor system can be divided into three main categories: a sensor acting as a switch, a circuit connecting the sensor and the device, and the device that acts as power control and system on/off. The functions are implemented in the texture touch sensor jacket in three modes: cell phone mode, music mode, and PPT presentation mode. We conducted an evaluation of each function in each mode, which indicated that all functions performed well without errors and that the switch had excellent operation for the number and intensity of touch. In terms of usability in a humid environment, the performance of touch functions was found to be equally implemented. In the temperature environment, neither high nor low temperatures caused issues with the functions. A wearing satisfaction assessment evaluated psychological satisfaction, clothing convenience, device convenience, device usability, and device effectiveness. This research jacket is thought to be desirable for the relatively bendable, flexible, and intimate sensor used on the clothing, and the circuit made of conductive fabric tape.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권6호
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• pp.760-770
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• 2016

A 12-bit 750 kS/s Dual-Sampling Successive Approximation Register Analog-to-Digital Converter (SAR ADC) technique with reduced Capacitive DAC (CDAC) is presented in this paper. By adopting the Adaptive Power Control (APC) technique for the two-stage latched type comparator and using bootstrap switch, power consumption can be reduced and overall system efficiency can be optimized. Bootstrapped switches also are used to enhance the sampling linearity at a high input frequency. The proposed SAR ADC reduces the average switching energy compared with conventional SAR ADC by adopting reduced the Most Significant Bit (MSB) cycling step with Dual-Sampling of the analog signal. This technique holds the signal at both comparator input asymmetrically in sample mode. Therefore, the MSB can be calculated without consuming any switching energy. The prototype SAR ADC was implemented in $0.18-{\mu}m$ CMOS technology and occupies $0.728mm^2$. The measurement results show the proposed ADC achieves an Effective Number-of-Bits (ENOB) of 10.73 at a sampling frequency of 750 kS/s and clock frequency of 25 MHz. It consumes only 0.13 mW from a 5.0-V supply and achieves the INL and DNL of +2.78/-2.45 LSB and +0.36/-0.73 LSB respectively, SINAD of 66.35 dB, and a Figures-of-Merit (FoM) of a 102 fJ/conversion-step.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1868-1870
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• 2000

As a drive for an ETC (Electro-thermal Chemical) launcher, a large pulse power system of a 2.4MJ energy storage was designed, constructed and tested. The overall power system consists of eight capacitive 300kJ energy storage banks. In this paper we describe the design features, setup and operation test result of the 300kJ pulsed power module. Each capacitor bank of the 300kJ module consists of six 22kV 50kJ capacitors. A triggered vacuum switch (TVS-43) was adopted as the main pulse switch. Crowbar diode circuits, variable multi-tap inductors and energy dumping systems are connected to each high power capacitor bank via bus-bars and coaxial cables. A parallel crowbar diode stack is fabricated in coaxial structure with two series 13.5kV, 60kA avalanche diodes. The main design parameters of the 300kJ module are a maximum current of 180kA and a pulse width of 0.5 - 3ms. The electrical performances of each component and current output variations into resistive loads have been investigated.