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LED 조도제어 시 특성변화를 최소화하기 위한 PWM 주파수 선택방법
유진완(Jin-Wan Yoo),이무현(Mu-Hyun Lee),박종연(Chong-Yeun Park) 전력전자학회 2010 전력전자학술대회 논문집 Vol.2010 No.7
LED의 조도제어 방식은 타 방식에 비해 비교적 광색의 변화가 작고, 선형적인 조도제어가 가능한 PWM 방식을 사용한다. 본 논문은 LED를 PWM 방식으로 조도제어 했을 때, PWM 주파수에 의해 변화 하는 LED의 특성변화를 최소화하도록 주파수를 선택하는 방법을 제안하였으며, 이를 실험적으로 검증하였다.
수동 역률 보상회로를 이용한 LED 센서등 회로의 개발
유진완(Park, Chong-Yeun),이학범(Yoo, Jin-Wan),박종연(Lee, Hak-Beom) 강원대학교 산업기술연구소 2012 産業技術硏究 Vol.32 No.1
In this paper, We studied LED(Light Emitted Diode) sensor lights system using PIR(Pyroelectric Infrared Ray) sensor, CdS and MCU(Micro Controller Unit). And applied the valley fill circuit to improve the power factor. We designed the amplifier for each sensor and the LED driver for constant current which is the buck converter. Also, we proposed the algorithm of LED control by each sensors using MCU. Experimental results showed that power factor is 92% with valley fill circuit.
Y형 밸런싱 트랜스포머를 적용한 AC초퍼 LED 구동 시스템
김진구(Jin-Gu Kim),유진완(Jin-Wan Yoo),김용하(Yong-Ha Kim),박종연(Chong-Yeon Park) 한국조명·전기설비학회 2015 조명·전기설비학회논문지 Vol.29 No.3
The AC-LED driving system which is connected directly to alternative current source is suitable for commercialization because of its simple structure and low cost. However, it requires additional circuits compensating for current differences between the parallel connected LED strings. In this paper, we proposed the circuit compensating for current error of the three LED strings using the Y type balancing transformer. The proposed Half-bridge AC Chopper LED driving system used the ferrite materials balancing transformer. at the same time, it is able to dimming control. The proposed system is applied to 80W AC-LED module consist of three parallel strings. Experiment results present that Power factor and THD measured with power analyzer are 0.958 and 26.473% respectively satisfied with IEC61000-3-2 harmonics standard.
DBI 구조의 전자식 안정기를 이용한 70W CDM 램프용 조광제어 시스템 개발
최왕섭,유진완,박종연,Choe, Wang-Seop,Yoo, Jin-Wan,Park, Chong-Yun 강원대학교 산업기술연구소 2011 産業技術硏究 Vol.31 No.2
Ceramic metal halide lamps have been widely used due to long lifetime, high luminous efficiency and good colour rendering. In this paper, we developed dimming control system of electronic ballast for 70W ceramic metal halide lamp by using 1-10V interface. The proposed electronic ballast is consists of EMI filter, Full-wave rectifier, Active PFC, DBI(Dual Buck Inverter), Igniter and control circuit.It enables to supply both low-frequency rectangular wave voltage and current to the lamp by using DBI(Dual Bcuk Inverter) structure. By using 1-10V interface, the system that able to dimming the lamp is demonstrated by P-spice simulation and experimental results.