• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.4
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• pp.327-331
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• 2014

LED(Light Emitting Diode) is a semiconductor device utilizing electroluminescent effect is a phenomenon in which a type of P-N junction diode, the light of short wavelength which a voltage is applied in the forward direction is released. LED is advantageous in reducing the energy as environmentally materials that can greatly reduce the carbon emissions, recent it has attracted attention IT(Information Technology) and GT(Green Technology) industry. In addition, there are advantages long life, high efficiency, and excellent response speed, LED have come into the spotlight as the illumination means to replace the existing fluorescent light and incandescent light bulb. When connecting to MR16 electronic transformer for existing LED driver circuit, due to malfunction of the dimmer and the electronic transformer, flicker occurs and linear dimming is not possible. Therefore, in this paper, we suggest an LED drive circuit there is no flicker with the corresponding dimming MR16 electronic transformer. Further, we explain the principles of the LED current control technique and the principle of the drive circuit of the LED, in order to validate the proposed circuit through prototyping and simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1383-1388
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• 2011

Due to many recent activities on enforcement of the intensified environmental regulation such as the policies of curbing the greenhouse gas and the Restriction of Hazardous Substances (RoHS), the usage of Light emitting diode (LED) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we propose an energy-efficient control scheme of LED light, being composed of multiple light sources. The proposed scheme controls the intensity of LED light source to minimize the total intensity while providing the quality of lighting service. The intensity of light is assumed to be proportional to power consumption, thus the objective is to minimize the total power consumption. A linear programming problem is formulated to find the optimal intensity of each light source and procedure to apply the proposed scheme in the real system is suggested. The performance evaluation results elucidate that the proposed scheme achieves over 20% improvement in power consumption of light intensity in comparison with the conventional dimming control scheme.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.114-119
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• 2011

There is a limit to technology of improving luminous intensity uniformity and glare, known as a weakness of existing LED lamp. Because of Using many LED, LED lamp not only waste energy but have bad effect on efficiency. Our goal is to develop security lights solution which is contented with suitable area in KS(Korean Industrial Standards) and to remove glare by combining asphere in optical system with different concept. To improve luminous intensity uniformity, a reflect mirror system was used after an aspheric optical system design for this study. We made a mirror and measured it after analysing luminance changes depend on aspheric shapes with simulation program to see if aspheric shapes effect luminance distribution. We made progress to find problems and improve them by comparing measured data and analysed data. This result of the study will contribute to industry of LED lighting through developing solution of emotional illumination of LED security lights by knowing the importance of reflectivity with this study and improving luminous intensity uniformity with solving the problem.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.223-229
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• 2011

In this study, two types of LED spot light with the development of the current broadcast studio-light is installed in the space being used in many products, companies in the UK Arri-650W, 1000W Fresnel spot light and illumination, color temperature and color rendering comparison of data measured compared with the target of the shooting and the color rendition on images was measured by comparing the color. In the future, broadcast - shooting LED spot light replacing whether the available studies on the performance evaluation were analyzed. Experimental evaluation of a replacement for halogen lights in LED Spot light is potential was confirmed.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.395-400
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• 2017

As a serial communications protocol, Modbus has become a practically standard communication protocol and is now a commonly available means of connecting industrial electronic devices. Therefore, all devices can be connected using the Modbus protocol with the measurement and remote control on ships, buildings, trains, airplanes and more. The existing Modbus that has been used is based on serial communication. Modbus TCP uses Ethernet communication based on TCP / IP which is the most widely used Internet protocol today; so, it is faster than serial communication and can be connected to the Internet of Things. In this paper, we designed an algorithm to control LED lighting in a wireless Wi-Fi environment using the Modbus TCP communication protocol, and designed and implemented a LED controller circuit that can check external environmental factors and control remotely through the integrated management system of a ship. Temperature, humidity, current and illuminance values, which are external environmental factors, are received by the controller through the sensors, and these values are communicated to the ship's integrated management system via the Modbus protocol. The Modbus can be connected to Master devices via TCP communication to monitor temperature, humidity, current, illuminance status and LED output values, and also users can change the RGB value remotely in order to change to the desired color. In addition, in order to confirm the implementation of the controller, we developed a simulated ship management system to monitor the temperature, humidity, current and illumination conditions, and change the LED color of the controller by changing the RGB value remotely.

• KIEAE Journal
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• v.13 no.4
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• pp.63-68
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• 2013

On the electricity consumption in Korea, the lighting sector takes about 17% of annual total electricity consumptions. In the midst of higher interests on energy conservation measures, design and choice of energy-saving lighting fixtures have been more important. With growth of technology-intensive industries like advanced material, semiconductor, and biotechnology from the 1980s, needs for clean room and thus illumination at clean rooms have been increased. In this paper, development, specification, and features of a Teardrop LED(hereinafter TD LED) lighting fixture as replacement of Teardrop florescent lighting one that has been popularly installed at clean rooms were presented. Also we performed the economic analysis of return on investment(ROI) about energy savings by the installation of the TD LED lighting fixture at a new-built clean room. The economic analysis showed that the new-developed TD LED lighting fixture would be able to withdraw the initial installation cost within 4 years. Lastly, improvement directions and development plans of the next TD LED lighting fixture for wider applications at clean rooms were described.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.188-193
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• 2011

For a long time work or study, pendent task lighting system prepared with phosphor luminescent film LED was developed for eye protection and working efficiency improvement. Developed lighting system was used together with pendent and ambient lighting. Such as, we made comfortable lighting environment system. Evaluation for developed lighting system, that had proceeded to Mock-up test and subjective evaluation. Also It had proceeded that lighting environment analyzed and compatibility valuation of installation. In subjective evaluation, the students have expressed themselves satisfied to phosphor luminescent film LED lighting system. In Mock-up test, It is not problem to intensity of illumination, luminance and color temperature. Therefore, developed LED lighting system was installed at the Daegu apartment. It is having a P.O.E study progress to phosphor luminescent film LED lighting system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.1-7
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• 2015

The Light Emitting Diode(LED) lighting control system proposed in this thesis is made up of a sensor module, a microcontroller, Bluetooth wireless communication, LED Driver, and LED downlight. The sensor module, comprised of an infrared sensor, an illumination sensor, and a temperature sensor, was designed to one Printed Circuit board(PCB). The system is able to identify the environment information collected by the sensor, and make it possible to control lighting automatically and manually through sensors. In addition, depending on users' conditions, a color temperature can be controlled. CS-1000, a spectroradiometer, was employed to measure the changing values of a color temperature in 8 steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5598K of Cool White LED. The Bluetooth based wireless communication technique makes it possible to control more lighting devices than other wireless communication techniques does.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.846-847
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• 2016

LED lighting is energy in lighting control based on had developed into a human-centered / multi-functional lighting systems from simple one trillion people thereby using environmental change by combining IT technology and software, including a variety of sensor functions and communication functions, depending on the evolution of the IT Convergence Era the reduction, and the strength and the color tone customized illumination of the user-section of light has been desired. For this intelligent lighting system is applied to the sensor and the control center of the user should be possible, and it is necessary for this artist platform of the communication module. In this paper, we propose a communication platform that utilizes Bluetooth BLE module for LED lighting control.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.1
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• pp.1-6
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• 2021

In this paper, to expand the use of standalone street lights, an algorithm for controlling LED energy consumption was proposed. The proposed method uses an LED module of a standalone street light divided into n zones. This is a method of reducing total power consumption by preventing the increase in power consumption due to high heat generation by weakly operating the entire LED according to the illuminance. When the amount of sunlight decreases, the whole LED operates weakly and then brightens, and unlike streetlight that act as streetlight, a method of dividing LEDs by area and limiting the number of LEDs operating according to illumination intensity was proposed. This is a way to use a lot of time with limited battery capacity by reducing the generation of heat that consumes the most power in streetlight. It is also a method of continuously changing the initial usage area to improve the total usage time of the LED substrate. As a result of the experiment, it was found that the proposed method extends the service time because it generates less heat than the conventional stand-alone streetlight.