• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.237-238
• /
• 2015

본 논문은 스위치 동작 듀티에 따른 등가임피던스가 광범위하게 변화 하는 벅부스트 컨버터를 이용하여 전자식, 자기식 안정기 모두 호환 가능한 LED(Light Emitting Diode) 구동회로를 제안한다. 현재 사용되는 안정기는 상용 주파수를 출력으로 가지는 자기식 안정기와 LCC 인버터를 거쳐 수십kHz 주파수 출력을 가지는 전자식 안정기가 있다. 제안 회로는 안정기출력 주파수 특성 차이를 이용하여 High Pass Filter(HPF)를 통해 전자식 또는 자기식 안정기가 연결되었음을 감지하여 서로 다른 제어방식으로 동작시킴으로써 전자식 및 자기식 안정기 모두 호환이 가능하다. 본 논문에서 제안된 회로의 우수성을 검증하기 위하여 이론적 분석 및 16.8W급 LED 구동회로에 적용한 실험결과를 제시한다.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.934_935
• /
• 2009

LED는 기존조명에 비해 친환경적이고, 긴 수명을 갖기 때문에 현재에 이르러 광고조명이나 백라이트 유닛 그리고 실내 외 조명으로 각광받기 시작했다. LED를 조명으로 사용 함에 있어서 LED의 PN 접합부에서 발생하는 접합온도 상승을 고려해야한다. 접합온도 상승은 LED의 광 출력과 수명의 감소, 광색의 변화를 초래하기 때문에 광 출력 및 광색을 유지시키고, 수명을 예측하기 위해서는 LED의 접합온도를 일정하게 유지시키는 LED 전용의 전력제어 시스템이 필요하다. 본 논문은 LED 접합온도 측정 시스템과 구동전원을 설계 및 제작하였으며, 측정된 온도를 구동전원에 궤환시켜 접합온도를 일정하게 유지시키는 시스템을 제안하였다.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.331-332
• /
• 2013

본 논문은 기존의 수동소자만을 가지는 LED 구동회로 동작 시 상용전원인 입력전압 변동에도 정적으로 LED 전력을 제어하는 LED 구동회로를 제안한다. 패시브 구동회로에서 입력전압이 변동할 경우 LED에서 소모되는 전력이 변동하는 문제를 해결하고자, 제안된 다단 스위칭 회로를 이용하여 LED의 개수를 조절함으로써 LED 전력을 일정한 범위 내에 동작하도록 제어하였다. 실험결과 입력전압대비 LED 전력변동률 $dP_o/dv_s$는 0.26임을 확인하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.4
• /
• pp.191-198
• /
• 2015

The purpose of this study is to develope a current variation control system appropriate to the various LED(Light Emitting Diode) lamps using current control system equipped with microcontroller based voltage regulator of power driving circuit. For this, we will suggest a stable control system of current variation to enable a stable power-supply and current-control, consisting of circuit to minimize the affects on the LED forward voltage using variable resistance and compensating resistance. The method of constant current circuit and energy savings using microcontroller based voltage regulator suggested in this study can be applied to various a big capacity LED lamp to minimize the unnecessay heat generation and to control resistace delicately. Ultimately, we expect the results of this study will upgrade the reliability of LED lamp by supplying the current stably.

• Journal of Advanced Navigation Technology
• /
• v.15 no.6
• /
• pp.1111-1117
• /
• 2011

We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has produced for use in mobile that can be driven at low voltage. In addition, it was also possible to implement a variety of colors from monochromatic Light to polychromatic light using by PWM control method and were available 32,768.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.10
• /
• pp.4740-4744
• /
• 2012

The purpose of this paper was to make a LED light control module using Zigbee. The module was made so that brightness of the LED light changes according to the ambient brightness. A 8-bit microcontroller was used to implement the module to enable LED dimming and wireless light intensity measurement. Using the proposed method, power consumption can be improved by up to 48% on average, with 3.4-0.4W changes in power. The measured ambient light intensity values are converted from analog to digital and outputted as a PWM waveform. According to the output waveform and changes in the current outputted from the LED driver, the brightness of the LED light is controlled. Also, Zigbee with close-range wireless communication capabilities was used to enable wireless transmission of light intensity measurements.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.509-510
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.403-404
• /
• 2009

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.15-16
• /
• 2012

General lighting will be replaced into LED due to the high efficiency, low power consumption, long life than conventional light, moreover, since it is a basically semiconductor device that can convert the electric energy to visible light at a very high speed, using these characteristics can be performed communication modulation via the high-speed ON-OFF switching. Recently, visible light communication (VLC: Visible Light Communication) technology is received attention and there have been many researches. This paper is implemented media signal transmission by combining LED with VLC, a transmitter used the LED light-emitting device and receiver used an infrared sensor. In order to increase the efficiency of the communication system to improve the existing LED visible light communication driver of power conversion efficiency and thermal issues that is applied to the visible light communication in order to improve the speed of transmission media to research a new way of LED driver.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.4
• /
• pp.1797-1805
• /
• 2012

In this paper, Power LED(Light Emitting Diodes) is studied to driver as a new lighting system in the spotlight, replacing a large existing lighting system with fluorescent and incandescent lighting. To take advantage a variety of DC power as the boost DC-DC converter design specifications through the inductor L and capacitor C through PSPICE to calculate the best estimate of the value. Converter's switching frequency is 50[kHz], the first Duty Rate was made to increase gradually depending on the value of the detection were, 10[%] in the output voltage. As a result, the simulated Boost Power LED driver characteristics is in comparison with the design specifications, 5[%] or less as the error was approximated. So, when input 15[V] were offered, a stable output 24[V] were obtained, and Dimming Control through the adjustment of brightness and current consumption were obtained to possible result.