• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.85-92
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• 2018

In this paper, we designed a 150W LED lighting SMPS circuit operating at $-40^{\circ}C$. We designed a 150W LED lighting constant current circuit for the characteristics of the SMPS and fabricated and measured. The operating temperature range for a 150W LED lighting SMPS circuit is -40 to $70^{\circ}C$ and SMPS predicted life was 1.29-2.25 years based on 24 hours. The high acceleration life test and EMI test confirmed no abnormality.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.534-535
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• 2013

최근 LED 기술을 활용한 LED 조명은 밝기와 수명 및 저전력이라는 장점으로 인하여 현재 시중에 급속도로 퍼저 나가고 있다. 이러한 LED를 조명으로 사용하기 위한 기반 기술은 SMPS(Switching Mode Power Supply) 설계 기술이라 할 수 있다. 또한 LED 성능은 입력 전원 상태 및 LED 조명의 부하 조건에 따라 오차가 발생하여 LED등의 균일한 밝기를 유지하는데 기술적으로 많은 어려움이 있다. 본 논문에서는 12[W] 급 LED 다운 라이트에 대하여 LED SMPS의 전류 출력에 대하여 정전류제어를 함으로서 입/출력 조건의 변동에 대응하여 보다 안정적인 LED 등의 균일한 밝기를 유지하기 위한 12[W] 급 LED 다운 라이트용 SMPS에 PFC(Power Factor Correction) 회로를 추가하여 역율을 개선을 하며, 전압 위상에 따른 전류 위상 분포를 규일 비율로 제어 하여 보다 안정적인 밝기를 제공하는 12[W] 급 LED 조명용 SMPS를 개발하여 상품화를 제안하고자 한다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.431-432
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• 2014

Recently, the demand of LED(light-emitting diode) lighting is gradually enlarged by governmental saveenergy policy, which the LED lighting has been established compulsorily in new buildings, public institutions, and residential installations etc.. The LED lighting is driven by SMPS (switching mode power supply). The SMPS requires high efficiency because the SMPS changes a commercial ac power source to low voltage dc power source. Harmonic components that occur in the conversion process of SMPS decrease system power factor and deal great damage in electric power system. To improve such problems, this paper proposes a SMPS of high efficiency. The switching devices in the proposed SMPS are operated by soft switching technique using a new quasi-resonant circuit. The input ac current waveform in the proposed SMPS becomes a quasi-sinusoidal waveform proportional to the magnitude of input ac voltage under constant switching frequency. As a result, the proposed SMPS obtains low switching power loss and high efficiency, and its input power factor is nearly in unity.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.643-648
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• 2011

In this study, SMPS driven LED traffic signal light for Large-scale traffic such as railroad and airport was designed and its electrical and EMI characteristics were measured. The output current of the LED module driven by SMPS was 1.67A for AC and DC input voltage over 10V. The conducted emission measured over 0.15~30MHz frequency range was lower than the allowed quasi-peak and average level, and the radiated noise measured over 30~1000MHz frequency range showed $23.96dB{\mu}V/m$ at 59.96MHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.123-129
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• 2009

In this study, SMPS to drive LED traffic signal light for the railroad and airport was designed and its electrical characteristics was measured. The output voltage, output current and its power efficiencies to the input voltage 8~12VAC and 8~16VDC were 6VDC, 1.85ADC and >70%, respectively. Also the power factors of the SMPS were above 0.75 in the AC input voltage range.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.111-116
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• 2015

In this study, the constant current converter for LED lighting was designed and the electrical characteristics of the fabricated SMPS was measured. When the output current is 300mA the maximum efficiency of 85% was shown and the output current is in the range of 100~400mA efficiency over 70% were exhibited. Also the dimming levels control over the range of 0 to 100% was possible by using a control signal of 0~250mV.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.

• Journal of information and communication convergence engineering
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• v.19 no.4
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• pp.214-220
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• 2021

In this study, we constructed several scenarios that are required for LED lighting, and we designed and implemented an LED lighting control system to operate these scenarios to confirm their behavior. An LED lighting control system is a hybrid control board that is designed by combining LED controllers and SMPS, consisting of an AC/DC power supply part that converts AC 220 V into DC 12 V, and a drive and control part that controls the scenario and color of the LED module. Conventional LED light controllers have an input power of DC 12 V, so when using the input AC 220 V, the SMPS must be connected to the LED light controller. To eliminate this inconvenience, a hybrid LED lighting control system was configured to combine LED lighting controllers and SMPS into one control system. Furthermore, we designed a control system to represent the most appropriate color according to the input of the distance and illumination using a fuzzy control system to conduct computer simulations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.36-43
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• 2013

The prevalence of electronic devices in our modern life is accompanied with the generation of harmonics caused by the nonlinear characteristic load. Especially, the employment of LED have brought the rapid use of SMPS. SMPS is used for supplying the constant DC electric power to the LED display board, but it has a big problem which gives birth of harmonics causing by its high-speed switching. measurement HIOKI 3196 equipment to solve these harmonics were measured. In this study, we are LED Display Board Load Measuring the impedance response with $X_L$ changes for removing harmonics in the measured. And we adopted the suitable passive filter by the impedance response characteristic obtained in the $X_L$ variation experiments. We are trying to deeply the application of passive harmonic filter characteristics that generation in the LED Display Board through EDSA LED simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.271-276
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• 2014

LED lighting has received worldwide attention as advantages, such as environment-friendly than the conventional light, the excellent energy efficiency, and a semi-permanent lifetime. The use of the SMPS increased with the rapid growth in the LED industry. Increased use of SMPS means an increase in the harmonic generation load. Therefore, LED lighting compared with conventional fluorescent lamps were tested in this paper for characterized by a light source, electrical and harmonic characteristics. Experiments results for LED lighting showed different characteristics from the existing fluorescent lamp. Especially harmonic characteristic results showed different characteristics in accordance with the power device manufacturing method for LED lighting.