Design of LED Lighting Uninterrupted Constant Current Power Supply

Abstract:

This design uses ATMEG8L as the master chip, real-time detection the state of the main power supply DC voltage, by controlling the MOSFET has the ability to quickly turn off the main power and backup power to achieve seamless switching, switching time of less than 1ms; by controlling the MOSFET with the fast turn-off capability to achieve the main power supply and backup power seamless switching, switching time of less than 1ms; Valley-fill PFC circuit is used in the main power supply to ensure the power factor > 0.9, DC-DC buck circuit is composed of LM2576T - ADJ, when great fluctuations in input voltage, output voltage 8 v is very stable, error < 1%, DC-DC boost circuit composed by LM2577T-ADJ, the battery voltage decay process, to achieve a stable output voltage of 8V, LED constant current drive circuit composed by PT4115, adjustable output current and high precision, and then adjust the brightness of LED. Master control chip, through detecting the change of photosensitive resistance, control the duty ratio of PWM wave, In order to achieve LED brightness can be adjusted automatically with ambient light, Protection of the power transformer is perfect, efficiency > 85%.

• Periodical: Applied Mechanics and Materials (Volumes 687-691)
• Pages: 3235-3238
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.687-691.3235
• Online since: November 2014
• Authors: Xiao Min Han*
• Keywords: Continuous Constant Current Source, DC-DC Boost Circuit, DC-DC Buck Circuit, Valley-Fill PFC Circuit

References

[1] ZHANG Guangchao , DAI Dao-feng: The Analysis and Simulation of the Valley - fill Positive PFC Off -line Circuit, Journal of HuaiBei Coal Industry Teachers College(Natural Science), Vol. 35, No. 4 (2010) pp.29-31.

[2] HOU Dianli, ZHANG Qingfan, ZHANG Long: Improvement and Design of a LED Driver with PFC, Journal of Power Supply, No. 2(2011) pp.34-38.

[3] Chen Lei, Zhao Yanjun, Wang Yanling: The high-power LED constant current driven design Based on PT4115, Light & Lighting, Vol. 32, No. 4 (2008) pp.31-34.

[4] NI Xinlong, FENG Jinyuan: Design of front-stage EMI filter and protective circuit for LED driver, Chinese Journal of Power Sources, No. 5 (2014) pp.965-968.

[5] LUO Zhongliang, CHEN Zhiming: Design and Simulation of EMI Filter for LED Driving Power, Modern Computer, No. 3 (2013).

[6] ZHENG Yanli, QIN Huibin: Research of Passive PFC Circuits in LED Driver Circuit, Journal of Mechanical & Electrical Engineering, No. 6 (2011) pp.753-756.