• Journal of Multimedia Information System
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• v.6 no.4
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• pp.329-332
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• 2019

Recently, smart lighting systems are the combination between sensors and lights. These systems turn on/off and adjust the brightness of lights based on the motion of object and the brightness of environment. These systems are often applied in places such as buildings, rooms, garages and parking lot. However, these lighting systems are controlled by lighting sensors, motion sensors based on illumination environment and motion detection. In this paper, we propose an automatic lighting control system using one single camera for buildings, rooms and garages. The proposed system is one integration the results of digital image processing as motion detection, hand gesture detection to control and dim the lighting system. The experimental results showed that the proposed system work very well and could consider to apply for automatic lighting spaces.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.31-36
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• 2015

In this paper, an LED lighting system that is capable of automatic or maunal dimming control using a ultrasonic sensor and Bluetooth wireless communication technology is presented. The LED lighting system consists of a ultrasonic sensor, microcontroller unit, Bluetooth wireless communication, LED driver, and LED light source. By using the implemented LED lighting system sample, it is shown that the automatic and manual dimming control is realized. By using the ultrasonic sensor, the LED lighting is automatically brighter or dimmer depending on the distance between the sensor and an object. When using a smartphone that includes Bluetooth wireless communication function, one can not only manually control the brightness of the LED lighting from level 1 to 10, but also monitor the distance between the sensor and object on the smartphone.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.6
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• pp.632-637
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• 2000

In this paper, to control with light dimming levels of the fluorescent lamps, we have used the power line instead of the signal line to transmit the control signals. To reduce the BER(Bit Error Rate) on the power line communication with the serious noise interferences. We have adapted the FSK(Frequency Shift Keying) modulation and demodulation technique. Since the electronic ballast produced the EMI(ElctroMagnetic Interference) noise in some frequency bands, we have reduced the EMI levels in the band below -50dB. By varying the switching frequency of the ballast for the FL032/T8 from 18kHz to 25kHz, it is possible that the dimming levels are controled with the range of 5∼100%

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.231-242
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• 2011

This study examines influences of a daylight dimming control system on the variation of indoor illuminance and lighting energy savings in a small office space. Field measurements and a series of computation were performed for typical types of sky conditions in summer. Results indicate that the daylight illuminance under clear and partly-cloudy sky were close to the target illuminance during a majority of time due to a higher ratio of window to wall. However, the target illuminance was not kept successfully due to the variation of photosensor signals which were strongly influenced by desktop illuminance. The system with partially-shielded conditions succeeded to keep target illuminance under clear sky conditions. The system failed under overcast sky conditions since the electric light output from fixtures caused excessive signals to photosensors due to insufficient daylight on a desktop. Unshielded and fully-shielded conditions were not recommended for effective controls of the systems. The influence of lighting fixtures on photosensors should be minimized to achieve successful lighting controls by daylight dimming systems.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.287-294
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• 2008

This paper describes an implementation of a wide-range dimming controller of a LED backlight for Avionics applications such as a control display unit(CDU) and multi-function display(MFD). The digital dimming controller employing a current controlled buck converter and light sensor feedback is proposed. The proposed system provides a wide dimming control range of from 150fL to 0.05fL(3000:1) required for avionic displays. The experimental results are provided to show the control performance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.149-152
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• 2000

This paper is on the edgelit device with external control function and change of light color by dimming control of high flux LED. It the light is projected the transparent body via reflector, the mixture of light is uniform and it is proved by simulation and experimentation. To improve the light efficiency of the device, the research on reflector materials and the distortion of LED input owing to the transistor's characteristics are need.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.277-280
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• 2007

Field emission-back light unit (FE-BLU) was fabricated using carbon nanotube (CNT) emitter. Local dimming and local brightening techniques were achieved, which results in very high contrast ratio. In addition, the motion blur phenomenon, one of the serious problems of liquid crystal display (LCD) with cold cathode fluorescent lamp (CCFL)-BLU, was removed from LCD-TV by using FE-BLU.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.101-104
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• 2008

This paper is a report of designing for LED lights driver unit. The main purpose of driver designing is high electrical efficient performance and intelligent control LED driver. This LED driver can be used for intelligent light control. This product expects to improve the light control by dimming instead of interlace on/off light control that increases the social cost such as car accidents and etc.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.32-38
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• 2020

In this paper, we analyze the modulation scheme for high speed transmission in visible light communication system, and study non-orthogonal multiplexing, dimming level and transmission power ratio. Conventional visible light communication has a disadvantage in that it is difficult to multi-transmit to increase the transmission speed. Multi-transmission technique is necessary for high-speed transmission at the transmitter. Since general visible light communication has a limitation in multiple transmission, various researches for high-speed transmission have been conducted. In order to solve this problem, this paper proposes a multiple modulation scheme for high-speed visible light communication using non-orthogonal multiplex transmission scheme and a future research direction.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2031-2039
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• 2015

In the LED lighting industry, the dimming function in the LED lamp is required by demands of many consumers. To drive this LED lighting, various types of power converters have been applied. Among them, an LLC resonant converter could be applied for high power LED lighting because of its high efficiency and high power density, etc. The function of power factor correction (PFC) might be added to it. In this paper, a dimmable single-stage asymmetrical LLC resonant converter is proposed. The proposed converter performs both input-current harmonics reduction and PFC using the discontinuous conduction mode (DCM). Also, the lower voltage stress across switching devices as well as the zero voltage switching (ZVS) in switching devices is realized by the proposed topology. It can reduce cost and has high efficiency of the driver. In addition, the regulation of the output power by variable switching frequency can vary the brightness of a light. In the proposed converter, one of the attractive advantages doesn’t need any extra control circuits for the dimming function. To verify the performance of the proposed converter, simulation and experimental results from a 300W prototype are provided.