• Title/Summary/Keyword: LED Driver

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Dimming Control of the LED Luminaire Emergency Exit Sign Operation using a Hybrid Super Capacitor of DC-DC Convertor (하이브리드 슈퍼커패시터 DC-DC 컨버터를 이용한 LED 비상 유도등 동작 디밍 제어)

  • Hwang, Lark-Hoon;Kim, Jin-Sun;Na, Yong-Ju
    • Journal of Advanced Navigation Technology
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    • v.21 no.3
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    • pp.220-229
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    • 2017
  • In this paper, 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. Boost DC-DC converter with a switch device using IRF840 and reverse recovery time Schottky diodes with excellent with constant current controller using D10SC6M and resistance can be configured to considering the Power LED Module was driven by the production. 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. Finally, 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 possible.

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

  • Cho, Chong-Duck;Shin, Seung-Sik
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.76-82
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    • 2006
  • Wheels' Direction Indicator, an electronic direction displaying system, provides a driver with information of wheels' direction in real time. The purpose of this study is to develop the system showing on LCD and LED with measuring steering wheel's movement. This system that applies a steering wheel's movement to the data process part will reduce inconvenience that confirms wheels' direction before throughout the open window before driving a car in parking lot.

Sliding Mode Current Controller Design for Power LEDs

  • Kim, Eung-Seok;Kim, Cherl-Jin
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.104-110
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    • 2011
  • High-brightness LED control is required for stable operation, thus the driver and control system must be designed to deliver a constant current to optimize reliability and ensure consistent luminous flux. In this paper, the sliding mode current controller is designed to adjust the illumination density of power LEDs. The controller design model of power LEDs, including its driving circuit, is proposed to realize the dimming control of power LEDs. A buck converter is introduced to drive the power LEDs and reduce the input voltage to a lower level. The sliding mode software controller is implemented to adjust the dimming of power LEDs. The proposed strategy for driving power LEDs is investigated and comparatively studied by experiments.

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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    • v.11 no.1
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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.

Implementation of fiber-optic temperature sensor system base on optical absorption device (광흡수 소자를 이용한 광온도 센서 시스템의 구현)

  • 김영수;김요희
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.9
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    • pp.128-134
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    • 1995
  • A fiber-optic temperature sensor utilizing an optical absorption device (InP) was fabricated. The spectrum of transmitted light through an InP device was obtained at the three temperatures(249 K, 369 K). A stabilized LED(light emmiting diode) driver, photoreceiver, and signal proocessing electronics were designed. An intensity referencing technique was adopted in order to minimize the fluctuation of output signal due to external pertubation of the transmitting optical fiber. The optical absorption edge of the InP device moves to longer wavelength at a rate of 0.42 nm / K, and energy gap of InP is 1.35 eV at room temperature. From these results, it is concluded that the InP device has temperature dynamic range of 300 K with LED of center wavelength of 940nm and spectral width of 50nm. The designed fiber-optic temperature sensor system showed good linearity within the temperature range from -30$^{\circ}C$ to + 150$^{\circ}C$.

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Study on User Interface for a Capacitive-Sensor Based Smart Device

  • Jung, Sun-IL;Kim, Young-Chul
    • Smart Media Journal
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    • v.8 no.3
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    • pp.47-52
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    • 2019
  • In this paper, we designed HW / SW interfaces for processing the signals of capacitive sensors like Electric Potential Sensor (EPS) to detect the surrounding electric field disturbance as feature signals in motion recognition systems. We implemented a smart light control system with those interfaces. In the system, the on/off switch and brightness adjustment are controlled by hand gestures using the designed and fabricated interface circuits. PWM (Pulse Width Modulation) signals of the controller with a driver IC are used to drive the LED and to control the brightness and on/off operation. Using the hand-gesture signals obtained through EPS sensors and the interface HW/SW, we can not only construct a gesture instructing system but also accomplish the faster recognition speed by developing dedicated interface hardware including control circuitry. Finally, using the proposed hand-gesture recognition and signal processing methods, the light control module was also designed and implemented. The experimental result shows that the smart light control system can control the LED module properly by accurate motion detection and gesture classification.

Development of Visible Light Communication (VLC) System Technology Based on High Brightness LED light (고휘도 LED 조명 기술을 이용한 고속 가시광통신 시스템 기술 개발)

  • Lee, Jong-Hyeok;Jang, Kyung-Soon;Kim, Byung-Gyu;Kim, Jin-Ho
    • Convergence Security Journal
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    • v.14 no.7
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    • pp.29-36
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    • 2014
  • In this study, we design and develop a VLC test-bed system which has been recently issued and focused as good convergence technology in the world. We classify the developed system into transmission part including analog LED driver module, digital signal modulation module, and receiver part with light sensing module and signal demodulation module. Then we introduce important characteristics and components. We analyze some factors for each module. To validate the communication of the designed VLC system, we develop a VLC sender-receiver simulator which can control the dimming factor and flicker-free effect. From the developed system, we observed about 12Mbps of data transmission rate with 0.5m~1m of distance, without packet loss. We verified the real-time communication with multimedia streaming which can be considered as very high date rate. The developed system and technology will be useful for some converged data services like indoor positing, home appliances, and indoor parking system.

A study on the development of 50W AC direct type engine with integrated reflector starting (리플렉터 일체형 50W급 AC 직결형 엔진개발에 관한 연구)

  • Son, Seok-Geum
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.4
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    • pp.388-393
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    • 2018
  • In this paper, We developed a high efficiency reflector integrated type 50W AC direct connection type engine to realize miniaturization and weight reduction of product without using SMPS and to design a multistage varistor circuit Reduced costs by reducing the number of parts High reliability is achieved by using a circuit structure that does not use an electrolytic capacitor, thus increasing the lifetime of the LED. In addition, it is possible to manufacture an AC direct-coupled type driving device by using an IC semiconductor and apply an AC direct-coupled type driving device integrated with a reflector so that the lifetime of the device can be fully utilized for the lifetime of the LED, A light source having a plurality of light emitting diode channels including a plurality of light emitting diode channels arranged in series is driven with a rectified voltage.

Development of Charge Indicator Inspection System for Plug-in Hybrid Electric Vehicle (PHEV용 Charge Indicator 시험기 개발)

  • Kim, Jin Young;Kang, Joonhee
    • Journal of Sensor Science and Technology
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    • v.25 no.2
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    • pp.155-159
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    • 2016
  • In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.

A Study on the Optimal Position of Vehicle Side Mirrors according to the Perception of Visual Information (시각정보의 인식도에 의한 자동차 Side Mirror의 최적 위치결정에 관한 연구)

  • 김도회;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.14 no.24
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    • pp.123-132
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    • 1991
  • This study deals with the experiment of perceiving visual information according to the positions of vehicle side mirrors. In the design of vehicle, the consideration of safety is very important. Therefore we consider the positions of side mirrors to use visual information effectively which is important factor to driver. This paper presents the position of side mirror to elevate the degree of visual perception for the circumstances of danger by experiments. To exhibit the circumstances of danger. 4 LED(Light Emitted Diode) art located at each side(right. left front. hack) of vehicle. A subject pushes the LED switch to see that if he perceives the circumstance of danger. To record the circumstance of randomly generated danger, computer interface card is used to control 4 LED and swithch on IBM PC/AT Experiments are divided into 2 parts. The 1st experiment present the independence of right & left side mirror. The 2nd experiment present optimal position of right & left side mirror. The vehicle used in experiment is model EL of H Co.. Statistical process of experimental data using SPSS(Statistical Package for Social Sciences)/PC package concludes that 1) the optimal position of right side mirror is 54cm forward of exist position. 2) for the left side mirror, the position of 120cm forward of exist position shows the worst degree of perception. and the optimal position does not exist in statistical meaning.

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