• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1247-1250
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• 2006

A new liquid crystal display (LCD) Data identified Time Extension (DiTEX) driving scheme with a high charged voltage is proposed. The different charged voltage owing to the differential charging time and various initial pixel-potential can be eliminated or diminished under this method. It is compatible with a 2-row inversion and can be realized into the commercial dual-sided gate circuits.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.625-630
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• 2005

In this paper, several energy recovery circuits (ERC) for the plasma display panel (PDP) are reviewed and classified in a manner of operation characteristics. A typical ERC using the Regenerative Transformer (RT) is introduced and compared with conventional ones. RT-ERC can achieve zero-voltage-switching (ZVS) for main full-bridge switches and zero-current-switching (ZCS) for the resonant switches and diodes. The charging/discharging energy of panel capacitance is efficiently recovered with the RT and without a sub-circuit. The presented circuit is verified with simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.4
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• pp.170-176
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• 2003

This paper introduces an improved pulse generator using power semiconductors and L-C circuit. The proposed circuit consists of the series connected boost converter structure. In the presented circuits, high voltage pulse is generated by series-connection of capacitors and IGBTs. The charging of capacitors and voltage balance of IGBTs are obtained automatically. To verify the proposed circuit, 1.8㎸, 40A pulse generator is manufactured and tested.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.249-252
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• 2001

A large number of soft switching topologies included a resonant circuit have been proposed. But these circuits increase number of switch in circuit and complicate sequence of switching operation. In this Paper, the authors propose power conversion system, DC-AC inverter of high efficiency and high power factor with soft switching mode by partial resonant method. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in partial resonant circuit makes charging energy regenerated at input power source for resonant operation.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.103-106
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• 2007

본 연구에서는 배터리의 특성에 알맞은 경제적이며 신뢰성 높은 충전특성을 가진 비상용 전기 설비용 충전시스템을 SMPS 기반으로 설계하여 제작하였다. 충전효율을 높이기 위해 정 전류방식의 충전회로를 구성하여 제작하였고 배터리 특성시험을 통해 그 타당성을 입증하였다.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.163-164
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• 2016

본 논문에서는 권선 사이의 자계결합도 변동을 고려하여 설계된 자기공진 방식의 전기차 충전용 무선전력전송회로의 효율 실험 결과를 제시한다. 특히, 동일한 시스템 사양에 대해 1차측 및 2차측에 각각 코일을 구비한 2-코일 방식의 회로와 1차측에 보조코일이 추가된 3-코일 방식의 회로를 각각 설계, 제작하였고 동등한 조건에서 두 방식의 효율을 비교하였다. 비교실험 결과 두 방식의 회로에 대한 효율이 크게 차이가 발생하지 않음을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.1
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• pp.84-87
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• 2016

In this paper, a receiver for wireless power transfer is proposed. The receiver consists of a 100 W rectifier in 1.8 MHz frequency band, and a constant current charger. In particular, two kinds of protection circuits are installed in the rectifier. They are a over-voltage protection circuit which block the input voltages greater than 30 V and a active-dummy load which maintains the receiver input impedance by automatically consuming the remaining input power. The constant current charger is designed to charge the battery with a charging current of up to 1 A. A wireless charging system is fabricated using the proposed receiver. The system is composed of a 130 W transmitter, two magnetic resonator, and proposed receiver for charging a 48 V Li-Ion battery using the coupled magnetic resonance method. By the measurement result, the system efficiency is about 54 %.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.523-523
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• 2012

As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.895-906
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• 2015

This paper presents a methodology and a model that can analyze the high frequency transfer characteristics from socket in the AC power port to the 5 V DC output port in the mobile charging circuit. This is to predict the output signals coming from the IEC(International Electrotechnical Commission) Standard(IEC 61000-4-4), EFT/B(Electric Fast Transient and Burst) immunity test for mobile charging circuit. Since the mobile charging circuit is energized from the AC power socket from the power line, it is necessary to know the high frequency transfer characteristics with activated AC power line. A simple CDN(Coupling-Decoupling Network) is designed and manufactured for measuring S-parameters of mobile charging circuit with and without AC power line activated. The result shows that the S-parameters of the specific mobile charging circuits are almost the same, independent of AC power line activation. Consequently, the S-parameters without AC line could be used to predict the output response to the EFT/B signals, and it was shown that the proposed methodology predicts the output responses quite accurately, which proves the validness of the methodology presented in this paper.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.506-511
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• 2011

In this paper, a rectenna for wireless power transmission at 900MHz is proposed. Rectenna is a device transforming RF power into DC power and it may consist of a antenna, rectifying and charging circuits. In this paper, we designed a slot antenna to receive 900MHz signal, a rectifying circuit of about 40% efficiency at 0dBm input, and a charging circuit to store a weak power signal and supply constant voltage to load. From the experiment using a RFID reader as a transmitter for 1W power, it was found that the proposed rectenna receiving about 0dBm power can supply 3.3V constant voltage to 50$k{\Omega}$ load during 280sec.