• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.663-666
• /
• 1999

This paper describes a three-phase converter with high power factor using a scheme of discontinuous current mode(DCM). The proposed system can replace the conventional diode bridge with step-up chopper which is used as a converter for adjustable speed drive. In this system, the current of reactor is zero at turn-on instance because of operation in DCM, while the switch turns off at the instance of maximum current. A soft-switching scheme with lossless snubber was proposed. Therefore, a zero-voltage switching at turn off can be achived by lossless snubber and zero-current switching at turn on can be obtained by operating under DCM. A theoretical analysis and computer simulations with PSpice were done to verify the operation of the proposed system. Also a prototype of hardware system was built and tested for verifying the feasibility of proposed system.

• Proceedings of the KIEE Conference
• /
• 2001.07c
• /
• pp.1685-1687
• /
• 2001

변전소 및 전력계통에 지락사고가 발생하면 변전소의 접지망에 사고전류가 유입하게 된다. 이 유입전류는 가공지선이나 변압기 중성선 그리고 기타 접지 망에 연결되어 있는 접지시스템에 의해 분류되는데, 모델변전소의 지락전류 흐름도를 모델화하여 Pspice 프로그램으로 대략적인 분류율을 계산하고, 실측치를 통해 지락사고시의 가공지선 분류율을 비교 평가하였다.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2792-2794
• /
• 1999

본 논문에서는 컴팩트 형광램프용 조도제어형 전자식 안정기의 각 동작 모드별 해석과 설계 및 실험적 고찰을 제시한다. 부스트 컨버터와 해프브리지형 고주파 공진형 인버터를 결합한 일단계 인버터 안정기를 제안하고 그 기본동작 및 특성에 관해 검토한다. 역률을 높이기 위한 방법으로 부스트단에서는 전류불연속 모드로 동작하도록 하였다. 전력 손실을 줄이기 위해 직렬 공진형 인버터는 영전압 영전류 스위칭 방식을 적용하였다. 출력 전압을 조정할 수 있도록 설계하여 조도제어를 구현하였으며 다단계의 조도제어가 가능해진다. 전자식 안정기 시스템을 구성하기 위한 이론적인 근거를 마련하기 위하여 공진형 인버터를 동작 모드별로 해석하고 그 결과를 토대로 동작주파수 및 회로정수를 결정하며, 실제 전자식 안정기를 제작하여 시동특성과 조광특성을 비교 분석하였다. 36W 형광램프에 대한 실험 결과와 등가회로 모델에 의한 Pspice 시뮬레이션 결과를 토대로 제안한 전자식 안정기의 적용가능성을 입증하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.282-282
• /
• 2010

LED Device was designed of electronic circuits of electrical power part for used Pspice student version and used Infrared LED lamps of load part. LED was used Computerized Electronic Medical Infrared Thermographic Imaging System for body surface Investigation of variable Body thermal asymmetry. It was knowledge body thermal Asymmetry of body surface and quantity body surface of electromagnetic wave to inflow electrical power part.

• Proceedings of the KIEE Conference
• /
• 2004.07e
• /
• pp.76-79
• /
• 2004

This paper proposed that the conventional three phase AC-DC converter with bulk LC output filter has been widely used in the industry because of simple circuit, low cost and high power factor (90%). One of the biggest drawback of this three phase AC-DC converter is bulk and heavy. This is serious especially for aerospace applications. To solve this problem a new simple three phase AC-DC converter is presented. Operation of the proposed high power factor three phase AC-DC converter is illustrated and verified by PSpice simulation.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.743-746
• /
• 2002

This paper proposes the design of a current-mode CCII-based 2$\^$nd/ _order bandpass biquad filter from a grounded series capacitor and frequency-dependent negative conductor ( C-D ) immittance function simulator using the macro model of a commercial available CCII+, AD844, from Analog Devices, Inc. The results are compared with the other results those are designed using ideal model of CCII-. The gain and phase deviations; due to the effects of passive sensitivity, active sensitivity, gain sensitivity and component variability; are considered using Monte-Carlo analysis of PSpice program.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.751-754
• /
• 2002

This paper introduces a way to realize biquadratic transfer functions using Operational Amplifiers (OAs) and Operational Transconductance Amplifiers (OTAs). The basic circuit configuration is constructed with two OAs and five OTAs. It is shown that low-pass, band-pass, high-pass, band-stop and all-pass transfer functions can be realized by suitably choosing the input terminals. And the circuit parameters can also be set by the transconductance gains of the OTAs independently. An example is given together with simulated results by PSPICE.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.6
• /
• pp.77-84
• /
• 1997

buck type converter doesn't appear when an input voltag eis lower than an output voltage. This is the main reason the buck converter has not been used for high power factor converters. In this paper, soft switching high power factor buck converter is proposed. This converter is composed of diode rectifier, input capacitor can be small enough to filter input current, buck converter with loss less snubber circuit. Converter is operated in discontinous conduction mode, turn on of the switching device is a zero current switching (ZCS) and high powr factor input is obtianed. In addition, zero voltage switching (ZVS) at trun off is achieved and switching loss is reduced using loss less snubber circuit. The capacitor used in the snubber circuit raised output voltage. Therefore, proposed converter has higher output voltage and higher efficiency than conventional buck type converter at same duty factor in discontinous conduction mode operation. High power factro, efficiency, soft switching operation of proposed converter is veified by simulation using Pspice and experimental results.

• Proceedings of the IEEK Conference
• /
• 2001.06b
• /
• pp.225-228
• /
• 2001

We simulated and analyzed the flicker phenomena in the poly-Si TFT-LCD using PSpice for the development of wide-area and high-quality LCD display We define the electric quantity of flicker in the TFT-LCD, which is the ratio of half frame frequency (30Hz) to DC (0 Hz) frequency. We compared two different types of TFTs, excimer laser annealed (ELA) poly-Si TFT and silicide mediated crystallization (SMC) poly-Si TFT, and found that the ELA and SMC TFTs show different flicker characteristics because of their mobility and leakage current. In addition, we showed that the gate voltage should be chosen carefully at the minimum flicker because of the larger leakage current of poly-Si Tn as compared with a-Si TFT

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.8
• /
• pp.8-21
• /
• 1997

In this paper, we consider resistive shorts on gate-source, gate-drain, and drain-source as well as opens in MOS FETs included in typical memory cell of VLSI SRAM and analyze behavior of memory by using PSPICE simulation. Using conventional fault models and this behavioral analysis, we propose linear testing algorithm of complexity O(N) which can be applied to both functional testing and IDDQ (quiescent power supply current) testing simultaneously to improve functionality and reliability of memory. Finally, we implement BIST (built-in self tsst) circuit and BICS(built-in current sensor), which are embedded on memory chip, to carry out functional testing efficiently and to detect various defects at high-speed respectively.