• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.4
• /
• pp.1-9
• /
• 2010

An LED driving and control circuit has been developed. The LED driver has a new PWM circuit for current control of LED columns with dimming, current and thermal control, and communication functions. The PWM circuit is composed of two ring oscillator and one counter which can be constructed using basic digital logic components. In addition, it has the functions of remote control mode such as ON, OFF, emergency and power saving modes by the serial communication. The PWM generator and control circuit have been designed and fabricated 0.35[${\mu}m$] Magnachip/Hynix digital IC fabrication process. The LED driving and control board using the developed chip is fabricated and tested successfully.

• The Journal of the Korea Contents Association
• /
• v.13 no.12
• /
• pp.19-26
• /
• 2013

In this paper, we present a novel illumination system for parking lots constructed underground. We design and implement this system using microwave sensors and dimming control of LED fluorescent lamps so that we can obtain lighting efficiency of the illumination scheme. We construct an effective illumination system in the aspects of performance and cost, resulting in energy-saving and electricity reduction. Recently conventional energy-saving method applied to old underground parking lots mainly relies upon turning off the half of total number of lamps installed in the parking lot. Sometimes there are some lots that have infrared sensor to be used to turn on/off the fluorescent lamps to realize these operations smoothing. The other schemes utilize timer to control lighting time of the fluorescent lamps. These conventional schemes are forcing to turn off a part of lamps installed so that we cannot apply them in a systematic way. Moreover they will be most inefficient when we leave them alone to be continuous consumers. The lighting control system proposed in this paper can recognize objects through microwave sensors and inform the appropriate lighting time, furthermore we can adjust brightness of LED lamps following the surroundings using dimming control scheme so that we can epochally improve the illumination system for underground parking lots. According to our sophisticated test experiments, we can maximally obtain 81.9% of energy-saving effectiveness using the system proposed in this paper.

• Journal of Sensor Science and Technology
• /
• v.28 no.3
• /
• pp.191-197
• /
• 2019

In this study, we propose a dimming control method for a visible light communication (VLC) system, in which the subcarrier on-off keying (OOK) modulation of Manchester code is used for data transmission. In the VLC transmitter, non-return-to-zero (NRZ) code data is transformed to Manchester code, which is OOK modulated with a subcarrier. Manchester code is used for flicker-free lighting; the duty factor is changed for dimming control, and the subcarrier is used for preventing the adjacent noise light interference. In the experiments, the dimming control was carried out from about 8%-92% of the continuous wave (CW) LED light. This configuration is simple and effective in constructing a VLC system for indoor wireless sensor networks with flicker-free illumination and dimming control capability without adjacent noise light interference.

• KIEAE Journal
• /
• v.16 no.4
• /
• pp.63-69
• /
• 2016

Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.11
• /
• pp.2786-2791
• /
• 2014

This paper describes the smart illuminating system based on the obstacle environmental presetting to improve the user convenience to easy lighting and energy conservation. Obstacle environment has trouble controlling the illuminating equipment using manual buttons in certain circumstances, which requires a smart remote controller. The smart remote controller is operated by the smart phone, motion sensor and timer to turn on and off the lamps. The event sensor module transmits the signals of the event occurrence to equipment on the remote place when smart phone and motion sensor detect an event, and the illuminator received the event turn on or off the lamp. The system results in energy saving by simple on/off control and manipulating the operating time with controlling the illuminating system preset by user's obstacle or preference circumstances. The proposed system implementation is experimented to figure out the energy saving about13.5w/h and the optimized convenience control.

• Proceedings of the KIPE Conference
• /
• 2004.07b
• /
• pp.822-825
• /
• 2004

This paper describes the improvement of performance of power supply for ship's emergency lighting system(SELS). Proposed system is composed of power factor correction (PFC) circuit, emergency power supply system (EPSS), half bridge(HB) inverter, fluorescent lamp(FL) starting circuit and microprocessor control system. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional relay type, and control power factor up to $97.5[\%]$ and input power up to $35.0[\%]$ by adjusting of pulse frequency of the HB inverter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.5
• /
• pp.16-26
• /
• 2004

As the importance of outdoor lighting become more widely recognized, outdoor lighting has been installed in many buildings, plazas, landscape, and historical monuments in Korea, Outdoor lighting on showing complex, in particular, express its values as local landmarks. However, the excessive outdoor lighting in the large-scale shopping complex tends to cause light pollution. Many advanced countries are trying to create a comfortable lighting environment by the guidlines and regulations on outdoor lighting to prevent light pollution. For this research backgrounds, the light pollution of three showing complexes in Seoul have been investigated. For the purpose, luminance of building facade, horizontal illuminance, and vertical illuminance were measured with proper measurement instruments and compared the results with the CIE recommendations. The results of the study are as follows. As no cut-off luminaries are currently installed on pedestrian walks, some glare were occured partially. It also shows that the luminance of building facades are high to improve the degree of public awareness of buildings and advertisements. In other words, the luminance of the building facade, when compared with that of the CIE recommendations, is twice as high and the vatical illuminance of pedestrian walks is far higher than that of the CIE recommendations, which proves the existence of light pollution. As Korea has not yet provided proper regulations or guidelines for the control of light pollution, it is necessary to make appropriate codes for it.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.283-283
• /
• 2010

Smart street light controller is a product with advance micro controller base for energy saving in conventional street lighting systems. Intelligent Street light controller are specially developed for automation and energy saving in conventional street light systems and lighting systems. It is so designed that it operates on sunrise & sun set timings according to longitude of particular location with facilitate to set month wise civil twilight timings to cope up with all seasons. Dimming (Power down) mode selection switch on/off at fixed times with relay or contactor. Night dimming, staggering and intelligent control reduces burn hours and increases the lifetime of lamps with about 30% and low annual operating cost type base are among the most inexpensive wireless technologies available. Low initial costs As PLC wireless, there is no need to establish cable connection.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.8 no.4
• /
• pp.38-45
• /
• 1994

It is very imprtant and necessary to predict luminous enviroment in an interior space. This paper has de scribed about energy saving and evaluated interior visual environment in a office building having on/off turning control lighting system utilizing daylight. In order to predict the interior varior illumination distribution, the scale model w a m~a de and examined under various conditions, such ad difference of window glass, and color pattern of wall, floor, and also ceiling lighting system type. Ths paper suggests that basic fundamental data of lighting design ~rformancein the concept and schematic stages of design.

• Journal of the Semiconductor & Display Technology
• /
• v.12 no.2
• /
• pp.13-17
• /
• 2013

In lighting system where several large-area organic light-emitting diode (OLED) lighting panels are involved, panel aging may appear differently from each other, resulting in a falling-off in lighting quality. To achieve uniform light output across large-area OLED lighting panels, we have employed an optical feedback circuit. Light output from each OLED panel is monitored by the optical feedback circuit that consists of a photodiode, I-V converter, 10-bit analogdigital converter (ADC), and comparator. A photodiode generates current by detecting OLED light from one side of the glass substrate (i.e., edge emission). Namely, the target luminance from the emission area (bottom emission) of OLED panels is monitored by current generated from the photodiode mounted on a glass edge. To this end, we need to establish a mapping table between the ADC value and the luminance of bottom emission. The reference ADC value corresponds to the target luminance of OLED panels. If the ADC value is lower or higher than the reference one (i.e., when the luminance of OLED panel is lower or higher than its target luminance), a micro controller unit (MCU) adjusts the pulse width modulation (PWM) used for the control of the power supplied to OLED panels in such a way that the ADC value obtained from optical feedback is the same as the reference one. As such, the target luminance of each individual OLED panel is unchanged. With the optical feedback circuit included in the lighting system, we have observed only 2% difference in relative intensity of neighboring OLED panels.