• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.535-538
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• 2005

We report the influence of the threshold voltage and mobility fluctuation in TFT on current mode digital circuit performance. We found that the threshold voltage showed more serious circuit malfunction. We studied new circuit configuration for improvement.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.778-781
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• 2002

In this paper, we designed the anti-fuse program circuit, and there are an anti-fuse program/sense/latch circuit, a negative voltage generator, power-up circuit and etc. in this circuit. An output voltage of a negative voltage generator is about -4,51V. We detected certainly it regardless of simulation result power rise time or temperature change to detect the anti-fuse program state of an anti-fuse program/sense/latch circuit and were able to know what performed a steady action. And as a result of having done a simulation while will change a resistance value voluntarily in order to check an anti-fuse resistance characteristic of this circuit oneself, it recognized as a programmed anti-fuse until 23k$\Omega$, and we were able to know that this circuit was a lot of margin than general anti-fuse resistance 500$\Omega$. Therefore, the anti-fuse program circuit of this study showed that was able to apply for configuration of the programmable logic device.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.9-17
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• 2020

Recently, RES (renewable energy source) projects have been spreading all over the world as an alternative to solve the shortage of energy and environmental problems caused by fossil fuel consumption. The Korean government also supported the policy and demonstration project to increase the proportion of renewable energy to 63.8[GW] until 2030, which is 20[%] of the total power generation. On the other hand, output loss of a PV array can occur when the surrounding high-rise buildings and trees shade a PV array. Therefore, this paper proposes an algorithm to improve the output loss of a PV array, which electrically changes a circuit configuration of PV modules by wiring and switching devices. Furthermore, this study modeled a PV system based on PSIM S/W, which was composed of a PV array, a circuit configuration device, and a grid-connected inverter. From the simulations results with the modeling and test device, the existing method showed no output when 50% of the shade occurs in PV modules. In contrast, the proposed method could produce the output because the voltage in the PV module could be restored to 246[V], and the operation efficiency of the PV system could be improved by the operation algorithm of the circuit configuration device.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1077-1083
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• 2014

Multi-material Additive Manufacturing (AM) is being focused to apply for direct manufacturing of a product. In this paper, a three-dimensional circuit device (3DCD) fabrication technology based on the multi-material AM technology was proposed. In contrast with conventional two-dimensional Printed Circuit Board (PCB), circuit elements and conducting wires of 3DCD are placed in threedimensional configuration at multiple layers of the structure. Therefore, 3DCD technology can improve design freedom of an electronic product. In this paper, 3DCD technology is proposed based on AM technology. Two types of 3DCD fabrication systems were developed based on the Stereolithography and the Fused Deposition Modeling technologies. And the 3DCD samples which have same function were fabricated, successfully.

• Journal of Power Electronics
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• v.5 no.3
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• pp.233-239
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• 2005

In this paper, a new conceptual circuit configuration of a 3-phase voltage source, soft switching AC-DC-AC converter using an IGBT module, which has one ARCPL circuit and one ARDCL circuit, is presented. In actuality, the ARCPL circuit is applied in the 3-phase voltage source rectifier side, and the ARDCL circuit is in the inverter side. And more, each power semiconductor device has a novel clamp snubber circuit, which can save the power semiconductor device from voltage and current across each power device. The proposed soft switching circuits have only two active power semiconductor devices. These ARCPL and ARDCL circuits consist of fewer parts than the conventional soft switching circuit. Furthermore, the proposed 3-phase voltage source soft switching AC-DC-AC power conversion system needs no additional sensor for complete soft switching as compared with the conventional 3-phase voltage source AC-DC-AC power conversion system. In addition to this, these soft switching circuits operate only once in one sampling term. Therefore, the power conversion efficiency of the proposed AC-DC-AC converter system will get higher than a conventional soft switching converter system because of the reduced ARCPL and ARDCL circuit losses. The operation timing and terms for ARDCL and ARCPL circuits are calculated and controlled by the smoothing DC capacitor voltage and the output AC current. Using this control, the loss of the soft switching circuits are reduced owing to reduced resonant inductor current in ARCPL and ARDCL circuits as compared with the conventional controlled soft switching power conversion system. The operating performances of proposed soft switching AC-DC-AC converter treated here are evaluated on the basis of experimental results in a 50kVA setup in this paper. As a result of experiment on the 50kVA system, it was confirmed that the proposed circuit could reduce conduction noise below 10 MHz and improve the conversion efficiency from 88. 5% to 90.5%, when compared with the hard switching circuit.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.52-56
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• 2009

In this research, we have studied the development of dc-dc converter suitable for the driving of mobile instruments by using a dye-sensitized solar cell(DSC). We also have designed a interlocking circuit. The circuit makes power generation be saved in one battery and concurrently be discharged in the other battery. As this application, mobile devices such as MP3, cellular phone are operated by using power generator from DSC during the daytime and they can be operated by using the saving energy of the daytime during the night. Consequently, it has a simple and robust circuit configuration. Besides, we designed dc-dc converter circuit to drive low power instruments by using NMOS switch and PMOS rectifier. Operational modes are analysed, and then validity of the proposed interface circuit is verified through DCS.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.953-958
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• 2001

The antifuse is a semi-permanent memory device like a ROM which shows the open or short state, and a switch device connecting logic blocks selectively in FPGA. In addition, the antifuse has been used as a logic device to troubleshoot defective memory cells arising from SDRAM processing. In this study, we have fabricated ONO antifuses consisted of PIP structure. The antifuse shows a high resistance more than several G Ω in the normal state, and shows a low resistance less than 500 Ω after program. The program resistance variation according to temperature shows the very stable value of $\pm$20 Ω. At this time, its program voltage shows 6.7∼7.2 V and the program is performed within 1 second. Therefore this result shows that the PIP antifuse is a very stable and programmable logic device.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.84-95
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• 1991

Mostly, phase control method is used to control the single phase AC power. The phase control method has some advantages such as ease to control and simple configuration. But the retardation of firing angle causes a lagging current even if load is purely resistive. So phase control causes a lagging power factor and a low efficiency at the input side in comparing with the system without switching device. A new PWM control method which can improve these defects for single phase AC power control circuit is proposed in this paper. The performances of the single phase AC power control circuit using the proposed method was investigated theoretically. Both power factor and waveform of load current can be improved better than those of the conventional methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.739-745
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• 2015

In this paper, a flexible wireless power receiving system is proposed for wearable device applications. The proposed system is designed with printable component configuration to be integrable to textile material. While the defected ground structures(DGSs) are utilized for planar printable filter designs, direct impedance matching technique is considered for flexible circuit performance. The proposed system has been implemented on a flexible substrate with a thickness of 5 mils, and experimented for power conversion efficiencies and converted voltages. In order to evaluate the hardware flexibility, the system performance are measured a bended circuit board at a radius of curvature of 5 cm. The system performance is analyzed for the degradation due to the curvature. The proposed system has shown the excellent capability of far-field wireless power transfer systems in flexible device environments.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.4
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• pp.335-342
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• 2016

This paper proposes an energy storage-assisted, series-connected module-integrated power conversion system that integrates a photovoltaic power conditioner and a charge balancing circuit. In conventional methods, a photovoltaic power conditioner and a cell-balancing circuit are needed for photovoltaic systems with energy storage devices, but they cause a complex configuration and high cost. Moreover, an imbalanced output voltage of the module-integrated converter for PV panels can be a result of partial shading. Partial shading can lead to the fault condition of the boost converter in shaded modules and high voltage stresses on the devices in other modules. To overcome these problems, a bidirectional buck-boost converter with an integrated magnetic device operating for a charge-balancing circuit is proposed. The proposed circuit has multiple secondary rectifiers with inductors sharing a single magnetic core, which works as an inductor for the main bidirectional charger/discharger of the energy storage. The secondary rectifiers operate as a cell-balancing circuit for both energy storage and the series-connected multiple outputs of the module-integrated converter. The operating principle of the cell-balancing power conversion circuit and the power stage design are presented and validated by PSIM simulation for analysis. A hardware prototype with equivalent photovoltaic modules is implemented for verification. The results verify that the modularized photovoltaic power conversion system in the output series with an energy storage successfully works with the proposed low-cost bidirectional buck-boost converter comprising a single magnetic device.