• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.285-293
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• 2004

In this Paper the electronic ballast using the SEPIC(Single Ended Primary Inductor Converter) converter for the multiple electrodeless fluorescent lamps is proposed, which has the structure of the active PFC and self oscillating function. The SEPIC converter system has the characteristics of the power factor with low input current harmonic distortion. The proposed control method is based on the aveage-current-mode using the dedicated integrated circuit UC3854. The proposed electronic ballast has the reduction effect for the energy and manufacturing cost because it is designed for tripple electrodeless fluorescent lamps. The experimental results shows that the power factor is higher and the THD is lower.

• Korean Journal of Optics and Photonics
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• v.17 no.2
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• pp.143-148
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• 2006

A new method of measuring the Brillouin gain spectrum of optical fiber is proposed and demonstrated. Unlike existing methods, both the pump light and the counter-propagating probe light are generated from a single laser diode whose optical frequency is directly modulated by injection current modulation. The frequency difference between the pump and the probe is scanned continuously through optical frequency chirp occurring when the injection current is modulated with a square wave. The measured Brillouin gain spectrum of telecom single-mode fiber agrees well with that shown in other literature.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.889-896
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• 2020

In general, there are various types of boost converters such as Boost converters, Buck-Boost converters, Flyback converters, Push-Pull converters, etc. Among them, Boost converters are the most widely used and step up converters in a very simple form. However, Boost converter has DCM mode operation, big ripple problem and RHPZ problem. In order to solve these problems, a converter to which the new topology was applied was presented, but among them, the KY converter improved the Boost converter's DCM mode operation, the big ripple problem and the RHPZ problem. However, the conventional KY converter has a drawback that the voltage gain is relatively lower than that of the Boost converter. Therefore, in this paper, we proposed a new KY converter that solves the problem of low voltage gain while having the advantages of the conventional KY converter.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.17-23
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• 2008

We have investigated the properties of the novel rectangular ring lasers containing active and passive regions in a InP material system. The rectangular ring laser consists of four low loss total internal reflection mirrors and a directional coupler made out of passive three waveguide. Two different lasers haying active lengths of 250 and $350{\mu}m$ and total cavity lengths of 580 and $780{\mu}m$ are fabricated, respectively. For both devices lasing thresholds of 38 mA is obtained at room temperature and under continuous wave operation. Lasing is predominantly single mode with the side mode suppression ratio better than 20 dB.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.56-57
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• 2016

본 논문은 LCC 공진형 컨버터를 기반으로 설계된 15kV, 1.5kJ/s 고전압 커패시터 충전기에 대하여 기술한다. 연속도전모드에서 동작하는 LCC 공진형 컨버터 설계를 통해 영전압 스위칭을 구현하고, 공진전류를 사다리꼴 형태로 개선하여 도전손실을 줄일 수 있도록 공진 파라메터를 설계 한다. 승압을 위한 고주파, 고전압 변압기를 다수의 환형 코어를 이용하여 설계하여 효율적인 기중절연을 확보하였다. 제작된 고전압 커패시터 충전기 프로토 타입의 저항부하 정격운전 및 커패시터 충전 실험을 통해 설계를 검증 하였다.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.27-28
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• 2013

이 논문에서는 부분 그늘짐에서도 다중 태양광 모듈의 최대 전력점 추종이 가능한 셔플링 차동전력 마이크로 컨버터를 설계 및 구현하였다. 마이크로 컨버터 시스템은 PV에 직접 연결된 셔플링 컨버터와 이후 단으로서 부스트 컨버터가 존재한다. 셔플링 컨버터는 다이렉트-시비율 기법을 통하여 PV모듈을 최대전력으로 동작시키고, 부스트 컨버터는 전압루프를 통하여 P&O 방식으로 최대 전력점을 추종하였다. PV 모듈에 병렬로 셔플링 컨버터를 적용함으로써, 다중 태양광 모듈의 전류 편차를 차동전력으로 조절하여 각각의 최대 전력점을 추종하면서 안정된 동작을 유지할 수 있다. 제안하는 컨버터는 2개의 PV모듈이 연결된 정상상태 연속모드 (CCM) 160[W]급 마이크로 컨버터 하드웨어 프로토타입을 통해 동작특성을 분석하였다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.52-62
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• 1996

In this paper, a new continuous-time current-mode integrator as basic building block of the low-voltage analog current-mode active filters was proposed. Compared to the current-mode integrator which was proposed by Zele, the proposed current-mode integrator had higher unity gain frequency and output impedance in addition to lower power dissipation. And also, a current-mode third-order lowpass active filter was designed with the proposed current-mode integrator. The designed circuits were fabricated using the ORBIT's 1.2.mu.m double-poly double-metal CMOS n-well process. The experimental resutls of the active filter designed and fabricated for this research have shown that it has the performance of 44.5MHz cutoff frequency, 3.3mW power dissipation and the third-order active filter area was 0.12mm$^{2}$.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.920-921
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• 2008

This paper presents the efficiency analysis of CCM(Continuous Current Mode) boost converter. A thorough efficiency analysis of a boost converter taking into account the conduction losses, the diode power loss, the switching losses, the gate-drive loss and the capacitive switching loss, for both continuous conduction mode is presented.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.200-203
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• 2002

This paper presents Continuous-current mode of $S^4$-PFC(Single-Stage Single-switch Power Factor Correction) converter. Proposed converter operates in the continueous current mode(CCM) at full load and discontinuous current mode(DCM) at light load. So, characteristic of proposed converter is no bus voltage stress and Zero Voltage Switching(ZVS) using resonant auxiliary circuit. And. This paper presents characteristic of $S^4$-PFC converter and effect of circuit parameter of proposed converter through the input inductor, PFC capacitor's variation. All of these theory and characteristic verified through the experiment with a 72W(12V, 6A), $90^{kHz}$ prototype converter.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.20-21
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• 2017

본 논문에서는 LCC 공진형 컨버터 토폴로지를 기반으로 한 10kW 급 고효율 DC/DC 컨버터를 설계, 제작하고 그 실험 결과를 기술한다. 제작된 컨버터는 공진 주파수 이상 연속 도전 모드에서 동작하도록 설계되어 도전 손실과 스위칭 손실을 줄일 수 있으며 다양한 부하조건에 대해 97% 이상의 높은 효율을 보인다. 컨버터는 최대출력 10kW를 발생시킬 수 있는 구조로 최대출력전압 500V, 최대출력전류 25A 조건으로 설계 되었으며, 실험은 경부하 조건에서 정격부하 조건까지의 동작을 확인할 수 있도록 제작된 모의 저항 부하를 사용하였다. 실험 결과 제작된 컨버터는 50% 부하 조건에서 97%, 정격부하 조건에서 98.5%의 효율을 보이는 것으로 확인되었다.