• 제목/요약/키워드: LED driving

검색결과 256건 처리시간 0.028초

복합환경제어를 위한 광량 센서장치의 최적구동 (Optimal Driving of Photo-Sensor for Control of A Mixed Environment)

  • 김종만;김원섭;김형석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.2110-2111
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    • 2011
  • Optimal Driving of Photo-Sensor for Control of a Mixed Environment was realized. The control system was carried out to investigate into the characteristics of Real time control of temperature and humidity at sprouts cutivators. Especially, for led's control for the cultivation of sprouts we have composed a Combined Automatic Control System possible for the control of temperature and humidity at the same time. The applied Photo-Sensor measurement are blue, green, red, white, yellow leds. And we had also designed the Web Programming for the automatic control about sprouts plants.

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On The Development of the Color Sequential LCD

  • Liu, Chia-Lin;Okita, Masaya;Huang, Chi-Fang;Mo, Chi-Neng;Tai, Wen-Chih;Chen, Kuang-Lang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1172-1174
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    • 2009
  • Color sequential display is a well know technology. Hower, due to the slow response time of LC,the CSD has not been used in LCD. We have developed a unique LC color display, which can improve LC response time, improve the driving system, improve the gamma drive issue and increase the color gamut to more than NTSC120%.It also can get very low power consumption merit.

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자연형 IVB(Independent Visual Background)의 Simulator Sickness 감소효과 (Effects of Natural Independent Visual Background for Reducing Simulator Sickness)

  • 김도회;임정위
    • 산업경영시스템학회지
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    • 제25권3호
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    • pp.28-33
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    • 2002
  • Several studies indicated that an independent visual background (IVB) reduced simulator sickness (SS) and balance disturbance associated with exposure to virtual environments (VEs) and motion simulators. A recent study showed that an IVB comprised of an earth-fixed grid was less effective in a complex driving simulator than in a simple VE. Subjects' post-experiment reports indicated that the VE motion "induced" motion of the earth-fixed grid m. This led to the suggestion that an IVB comprised of clouds would be less subject to induced motion and therefore would alleviate nausea more effectively than a grid IVB. Clouds are "natural" and are usually perceived as relatively stable, whereas a grid has no inherent stability. 12 subjects were exposed to complex motion through a simulated environment in a driving simulator under 3 IVB conditions: grid, less clouds, many clouds. They reported less nausea when the many-cloud IVB was used relative to the grid IVB condition. grid IVB condition.

급가속시 자동차 흡기계의 능동소음제어 성능향상 (The Performance Improvement for an Active Noise Contort of Automotive Intake System under Rapidly Accelerated Condition)

  • 이충휘;오재응;이유엽;이정윤
    • 한국자동차공학회논문집
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    • 제11권6호
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    • pp.183-189
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    • 2003
  • The study of the automotive noise reduction has been concentrated on the reduction of the automotive engine noise because the engine noise is the major cause of automotive noise. However, many studies of automotive engine noise led to the interest of the noise reduction of the exhaust and intake system. Recently, the active control method is used to reduce the noise of an automotive exhaust and intake system. It is mostly used the LMS(Least-Mean-Square) algorithm as an algorithm of active control because the LMS algorithm can easily obtain the complex transfer function in real-time. Especially, Filtered-X LMS (FXLMS) algorithm is applied to an Active Noise Control system. However, the convergence performance of LMS algorithm went bad when the FXLMS algorithm was applied to an active control of the induction noise under rapidly accelerated driving conditions. So, in order to solve this problem, the modified FXLMS algorithm is proposed. In this study, the improvement of the control performance using the modified FXLMS algorithm under rapidly and suddenly accelerated driving conditions was identified. Also, the performance of an active control using the LMS algorithm under rapidly accelerated driving conditions was evaluated through the theoretical derivation using a chirp signal to have similar characteristics with the induction noise signal.

자동차 바퀴 방향 지시기 개발에 관한 연구 (A Study on the development of wheels' direction indicator)

  • 조종덕;신승식
    • 전자공학회논문지 IE
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    • 제43권4호
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    • pp.76-82
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    • 2006
  • 자동차 바퀴 방향 지시기란 운전자가 차 내부에서 자동차의 바퀴 방향을 실시간으로 알 수 있도록 전자 장비에 바퀴의 방향을 표시해주는 시스템으로서, 본 연구에서는 자동차 핸들의 회전량을 측정하여 LED(Light Emitted Diode)와 LCD(Liquid Crystal Display)에 자동차 바퀴에 대한 방향 정보를 표시하는 시스템을 개발하고자 한다. 즉, 이렇게 자동차의 핸들 회전량을 측정하여 그 측정 데이터를 데이터 처리부에 적절하게 적용함으로써 자동차 내부에서 운전자가 인지할 수 있도록 해준다면 주차된 차를 주행하기 위해 자동차 창문을 열고 바퀴 방향을 봐야하는 등의 번거로움을 해소시킬 수 있을 것이라 사료된다.

LED 가로등의 각도를 이용한 광카메라통신기반 횡방향 차량 위치추정 기법 (Optical Camera Communication Based Lateral Vehicle Position Estimation Scheme Using Angle of LED Street Lights)

  • 전희진;윤수근;김병욱;정성윤
    • 전기학회논문지
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    • 제66권9호
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    • pp.1416-1423
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    • 2017
  • Lane detection technology is one of the most important issues on car safety and self-driving capability of autonomous vehicle. This paper introduces an accurate lane detection scheme based on OCC(Optical Camera Communication) for moving vehicles. For lane detection of moving vehicles, the streetlights and the front camera of the vehicle were used for a transmitter and a receiver, respectively. Based on the angle information of multiple streetlights in a captured image, the distance from sidewalk can be calculated using non-linear regression analysis. Simulation results show that the proposed scheme shows robust performance of accurate lane detection.

Single-Switch ZVZCS Quasi-Resonant CLL Isolated DC-DC Converter for 32'' LCD TV

  • Ryu, Seung-Hee;Ahn, Jung-Hoon;Cho, Kwang-Seung;Lee, Byoung-Kuk
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1646-1654
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    • 2015
  • In this paper, a single-switch ZVZCS quasi-resonant CLL isolated DC-DC converter for driving a low-power (less than 100 W) 32'' LED backlighting liquid crystal display television (LCD TV) is proposed. The proposed converter exhibits both forward and flyback operational characteristics. All semiconductors are activated and deactivated under the soft switching conditions during the switching transition without additional active devices. The switching frequency varies less than about 10 kHz for load variations, leading to minimizing the efficiency reduction under light load. Furthermore, the low di/dt and dv/dt by soft switching enhance the electromagnetic interference (EMI) performance above 1 MHz. A theoretical analysis is described in detail, and a 72-W prototype converter verifies the validity of the analysis.

An Efficient High Voltage Level Shifter using Coupling Capacitor for a High Side Buck Converter

  • Seong, Kwang-Su
    • Journal of Electrical Engineering and Technology
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    • 제11권1호
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    • pp.125-134
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    • 2016
  • We propose an efficient high voltage level shifter for a high side Buck converter driving a light-emitting diode (LED) lamp. The proposed circuit is comprised of a low voltage pulse width modulation (PWM) signal driver, a coupling capacitor, a resistor, and a diode. The proposed method uses a property of a PWM signal. The property is that the signal repeatedly transits between a low and high level at a certain frequency. A low voltage PWM signal is boosted to a high voltage PWM signal through a coupling capacitor using the property of the PWM signal, and the boosted high voltage PWM signal drives a p-channel metal oxide semiconductor (PMOS) transistor on the high side Buck converter. Experimental results show that the proposed level shifter boosts a low voltage (0 to 20 V) PWM signal at 125 kHz to a high voltage (370 to 380 V) PWM signal with a duty ratio of up to 0.9941.

LED 구동용 단일단 PFC CCM 플라이백 컨버터의 히스테리시스 최적 제어 (Optimal Hysteresis Control for CCM Driving of a Single-Stage PFC Flyback Converter for LED Lightings)

  • 김춘택
    • 전기학회논문지
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    • 제65권4호
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    • pp.586-592
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    • 2016
  • The current control of Continuous Conduction Mode(CCM) can be implemented by several methods: peak current control; average current control; and hysteresis control. Among these methods, the hysteresis current control is popularly applied in various converter applications because of its simplicity of implementation, fast current control response and inherent peak current limiting capability. However, a current controller with conventional hysteresis band which multiplies the current reference has the disadvantage that the modulation frequency varies in one cycle of the input voltage and, as a result, generates high switching frequency in the low input voltage section. Also it is complicated to design the input filter due to varying switching frequency. This paper proposed an optimum hysteresis-band current control method where the band is generated by using both multiplication method and sum method to maintain the modulation frequency to be nearly constant. This approach can solve the high switching frequency in the low input voltage section, and achieve easy design of input filter. The performance of the proposed converter is verified with the simulation and the experimental works.

스마트폰을 이용한 스마트 디퓨저의 프로토 타입 모델 설계 및 구현 (Design and Implementation of prototype model of Smart Diffuser using Smart Phone)

  • 최성재
    • 한국인터넷방송통신학회논문지
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    • 제20권4호
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    • pp.149-154
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    • 2020
  • 본 연구에서는 블루투스를 이용하여 스마트폰 으로 제어되는 Smart Diffuser 디바이스의 초기모델을 개발하였다. Smart Diffuser는 디바이스에 주입하는 오일을 분사시키기 위해 초음파 진동자를 이용하였다. 고휘도 LED를 사용하여 오일이 분사되는 동안에 색상 변화가 보여 지도록 디바이스를 개발하였다. 휴대용 디바이스인 점을 감안하여 충전 시간 문제를 해결하기 위해 40mAh의 Li-Po 배터리를 사용하여 장시간 사용할 수 있도록 설계를 하였다. Bluetooth Low Energy를 이용하여 저전력 구동을 구현을 함으로서 초기 설계모델의 유용성에 대해 확인 하였다.