• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.632-632
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• 2009

The purpose of this study is to present the range of defects mentioned in the Product Liability (PL) and to establish an objective basis and grounds for the analysis of accidents expected to happen by analyzing and presenting the external flame pattern and electrical characteristics of an LED streetlight lamp, a new lighting lamp. From the analysis of the cross-section of a cable carbonized by an external flame, it was observed that the wire's strand and insulation material had solidly adhered, and that greater voids were formed at the surface than at the center. Irregular carbide lumps were formed in the globe directly exposed to the flame, and the globe carbonized by the indirect flame showed characteristics that they had melted and flowed downward. It was found that the forward and backward resistances of the normal LED were approximately 1.74 [$M{\Omega}$] and 140 [$M{\Omega}$], respectively. The lamp burnt by the strong flame exhibited infinite forward and backward resistances and the LED did not emit light. The carbonized LED lamp was gray and exhibited fine delaminations. According to the Product Liability, a product defect signifies a simple product defect. Most of the defects were caused by the lack of stability, and the defect of the product itself occurred during the design and manufacture. The defects in warnings and markings include an insufficiency of handling manuals and warnings, expressive warranty violations, defective markings, etc. In order to prevent an accident resulting from a product, it is necessary to prepare safety warnings and documentation, establish clear-cut lines of liabilities, and subscribe insurances. However, it could be seen that important factors against the Product Liability were product improvement, response to compensation requests and law suits, credit restoration, etc.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.8-17
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• 2012

Unlike traditional lightings, LED lighting is one of objects that sends user an emotional segments through brightness control from various color temperature and dimming control. Also, within present interior lighting environment, emotional researches about traditional fluorescent lamp and newly implemented LED lighting environment are in active progress. Despite the fact adjectives describing emotions and scale modeling have been repeatedly used in many cases for a long time, there seems to be a lack of results in reliability, and there is a limitation for applying into actual lighting design. The purpose of this study is to construct an actual sized test-bed, which is used to draw out one's emotional words of behavior patterns from inner emotional experiences about lighting environment in an office space. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.759-765
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• 2012

In this paper, a temperature control for LED (light emitting diode) lamp using a cooling fan is studied. An efficient temperature control scheme for the LED lamp using the fan wind at the lowest sound noise is studied. For the study, after measurement of the minimum sound noise of the fan and related temperature of the LED lamp through tests, experiments on temperature control of the LED lamp using the fan with various size of heat sinks was performed. To reduce the fan sound noise, a method of reducing the operation time with optimal size of the heat sink was studied. Also, a control of LED lamps using RF communication was studied.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.315-323
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• 2021

Tunnel is the most energy-consuming structure in road due to the characteristic of using artificial lighting during day and night. Therefore, tunnel lights are being replaced by LED lamp that have advantages with respect to low power consumption. The best use of social overhead capital can be expected by considering the life cycle cost, because to tunnel structures are accompanied by a series of medium-to-long-term and continuous processes of replacing auxiliary facilities. In this study, the saving effect by LCC analysis was quantitatively analyzed by replacing tunnel light sources from high-pressure sodium lamps to LED lamps. The effect of reducing the replacement cycle by increasing the life of the lamps and the resulting maintenance cost is very significant, on replacing tunnel lighting light sources with LED lamp.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.145-147
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• 2003

This paper presents a method of improvement of color mixing in an RGB LED white lamp. The deviation from white light after RGB color mixing results mainly from the difference in the ray direction among LEDs. The authors propose a method using tilted lenses covered over each LED to deflect the overall direction of the ray generated from far-sited LEDs toward the center axis of the lamp. The degree of improvement is evaluated using a color discrimination method based on McAdam ellipse.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2196-2198
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• 2005

The luminous intensity distribution of a 1W high-power LED with a wide view angle should be concentrated to be used as a light source for an automotive reading lamp. In this paper, an optical lens made of PMMA is simulated by using an optical design software for that purpose. As the result, with the help of the devised lens, the reading light gives over 80 lx at the center of a target surface of radius of 0.2m located below 0.5m from the lamp, and a minimum of 20 lx at the perimeter of the target surface. Thus, a 1W high-power LED with an appropriate lens would suffice for an automotive reading lamp.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.191-198
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• 2015

The purpose of this study is to develope a current variation control system appropriate to the various LED(Light Emitting Diode) lamps using current control system equipped with microcontroller based voltage regulator of power driving circuit. For this, we will suggest a stable control system of current variation to enable a stable power-supply and current-control, consisting of circuit to minimize the affects on the LED forward voltage using variable resistance and compensating resistance. The method of constant current circuit and energy savings using microcontroller based voltage regulator suggested in this study can be applied to various a big capacity LED lamp to minimize the unnecessay heat generation and to control resistace delicately. Ultimately, we expect the results of this study will upgrade the reliability of LED lamp by supplying the current stably.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.553-554
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.357-358
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.403-404
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• 2009