• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.1-9
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• 2012

Memristor which is known as fourth basic circuit element has been developed recently but its electrical characteristics are not still fully understood. Memristor has the incremental and decremental feature of the resistance depending upon the connected polarities. Also, its operational behavior become diverse depending on its connection topologies. In this work, electrical characteristics of diverse types of serial and parallel connections are investigated using the HP $TiO_2$ model. The characteristics are analyzed with pinched hystersis loops on the V-I plane when sine input signal is applied. The results of the work would be utilized usefully for analyzing the characteristics of memristor element and applications to logic circuit and neuron cells.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.788-790
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• 1999

고주파 열처리 유도로의 설계에서 품질의 향상을 위하여 인버터의 고주파 기술이 요구되고 있다. 본 연구에서는 고주파 유도가열 장치의 대용량, 고주파 화를 실현하기 위하여 회로 설계 기술과 제어방식을 제안하였다. 부하 공진 인버터는 H형 전-브리지로 구성하고 각 암 당 IGBT를 2병렬로 조합하여 구성하고 부하는 직병렬 공진회로로 구성한다. 스위칭 동작은 8개의 IGBT중 각 암 당 2개씩 순차제어하여 고속 대용량의 고주파 전력을 출력시킨다. 또한 스위칭은 스위치 턴온 오프시에 스위칭 손실을 줄이기 위해 ZVS기법을 도입한다. 제어는 고정주파수 PWM제어를 하여 전력변환 효율을 극대화한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.31-40
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• 2008

Recently, Contactless Power Supply(CPS) system has been broadly studied as a power supply system for Flat Panel Display(FPD) material transfer equipments. In mass production line, CPS systems on material transfer equipment are applied only in the straight sections with single operating vehicle. The formal CPS system was not adequate for curved section nor multiple operating vehicles. Therefore, this paper presents CPS system that consists of straight and curved section with multiple operation vehicles. The circuit topology of CPS system consists of full bridge configured serial-parallel resonant DC/DC converter. The control method for CPS system consists of duty control method on the primary power supply system to maintain constant resonant current. And the secondary power supply systems of multiple vehicles are self controled to maintain constant output voltage. Practically, the test result of dual vehicles on straight and curved section of material transfer equipments were satisfactory, and proved it's applicability on commercial use.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.776-783
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• 2009

Current-cut circuit is an effective method to obtain low power consumption in wireless communication systems as high speed OFDM. For the operation of current-mode FFT LSI with analog signal processing essentially requires current-mode serial-to-parallel/parallel-to-serial converter with multi input and output structure. However, the Hold-mode operation of current-mode serial-to-parallel/parallel-to-serial converter has unnecessary power consumption. We propose a novel current-mode serial-to-parallel/parallel-to-serial converter with current-cut circuit and full chip simulation results agree with experimental data of low power consumption. The proposed current-mode serial-to-parallel/parallel-to-serial converter promise the wide application of the current-mode analog signal processing in the field of low power wireless communication LSI.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.1 no.2
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• pp.57-61
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• 1987

The characteristis of all the instruments and materials used in atomic industry are changed due to irradiation damages by the effects of radiation activities. In this study when R-C series-parallel circuits are irradiated by $\gamma$-ray, variations in its electrical properties have been investigated. The following results are obtained. 1) In the R-C series circuit, the impedance variation ratio is increased as the irradiation quantity is increased up to $10^6[r]$, and above $10^6[r]$, the impedance variation ratio reached at the saturated condition. In the saturated condition, the increasing value was about 1.25 (%). 2) In the R-C series circuit, the power factor variation ratio is decreased as the irradiation quantity is in creased up to $10^6[r]$, and above $10^6[r]$, the power factor variation ratio reached at the saturated condition. In the saturated condition, the decreasing value was about 0.5(%). 3) In the R-C parallel circuit, the impedance variation ratio is increased as the irradiation quentity is increased up to $10^6[r]$, and above $10^6[r]$, the impedance variation reached at the saturated condition. In the saturated condition, the increasing value was about 0.5.(%). 4) In the R-C parallel circuit, the power factor variation ratio is decreased as the irradiation quantity is increased up to $10^6$[r], and above $10^6$[r], the power factor variation ratio reached at the saturated condition. In the saturated condition, the decreasing value was about 1.3(%).

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.3
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• pp.57-66
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• 1993

This research proposes a high frequency series resonant inverter consisting of equivalent half - bridge model in combination with two L-C linked full-bridge inverter circuits using MOSFET. As a output power control strategy, the sequential gate control method is applied. Also, analysis of operating MODE and state equation is described. From the computer simulation results, the inverters and devices can be shared properly voltage and current rating of the system in accordance with series and parallel operations. And it is confirmed that the proposed system has very stable performance.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.411-412
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• 2017

본 논문에서는 전기자동차의 1회 충전 주행거리 연장 및 연비 향상을 위하여 주요 운전 영역에서의 평균효율 극대화를 할 수 있는 다단 변속 회로를 제안하였다. 제안한 회로는 Thyristor를 이용한 직 병렬 변속회로로 구성되어 있다. Thyristor의 특성으로 인해 과도상태 없고 끊김없는 변속이 가능하여 추가적인 스너버회로가 필요 없으며, 낮은 스위치손실로 인해 AC전동기 시스템의 고효율 및 경량화를 기대할 수 있다. 제안한 다단변속 시스템의 타당성을 검증하기 위하여 1kW 급 시작품 1대를 AC전동기와 연계하여 변속 동작을 검증하였다.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.46-47
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• 2010

일반적인 스위칭 콘버터의 교류 시변 특성을 시불변 회로로 변환시키는 페이저변환 기법이 차츰 널리 쓰이고 있으나 정적 응답특성을 구하는 데에 주로 국한되고 있다. 본 논문에서는 페이저변환 이론을 확장하여 단상, 다상의 모든 AC콘버터(DC-AC, AC-DC, AC-AC)와 모든 직병렬 공진형 콘버터(DC-DC)의 동적 응답특성을 일반적으로 구할 수 있는 새로운 이론을 제안한다. 본 논문에서는 복소 턴 비율(complex turn-ratio)을 갖는 전자변압기와 허수의 저항을 갖는 회로에 페이저변환을 적용하기 위해, 복소 라플라스변환을 도입하였다. 이를 통해 교류 콘버터 회로를 해석하고, 시뮬레이션을 통해 타당성을 검증하였다.

• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.56-59
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• 2002

In this study, new serial and parallel resistor and capacitor-frequency-dependent negative resistance configurations are implemented that use one plus type four-terminal floating nullor(FTFN) and three passive components. The values of simulated elements can be orthogonally adjusted without any matching condition. High pass filter designed with this FTFN and AD844. Computer simulation was performed using the AD844 macro model by HSPICE. Simulated results agree well with theoretical values.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.787-790
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• 2000

본 논문에서는 비교기의 설계 및 확장에 쉽게 이용할 수 있는 2bit 인코딩방법을 제안한다. 그리고 제안한 인코딩 방법을 이용하여 현재 비교기로 널리 사용하는 74LS85와 새로 설계한 5bit비교기에서의 직/병렬 N-bit로 확장했을 때의 응용방법을 비교한다. 또한 magnitude 비교기를 이용한 디코더 회로를 꾸며 음수 영역까지 확장할 수 있음을 보인다.