Research And Design On LED Driver Power

Energy-saving become the focus topic of global concern as the United Nations Climate Change Conference was held in Copenhagen in 2009. And it will lead to a more intense campaign of energy-saving, which will certainly promote the development of related technologies. Lighting is an important aspect of energy consumption. energy consumption of lighting accounts for about 20% of the total energy consumption in the world, so people take more and more attention at energy-efficient or"green"lighting .LED has many advantages of pollution-free, long life, high emitting efficiency. It has become the focus of the lighting field especially with the rapid development in recent years. It is no doubt that the environmental deterioration and current energy shortage will be alleviated If LED lighting replace traditional lighting of low efficiency and high energy consumption. LED lighting plays a decisive role. This paper focuses on LED driver circuit,All research are based on LED drive power with lower costs and. excellent driving performance This major work of this paper as follows:Paper first described the history of lighting, then described the development of LED status and application prospects from the characteristics and advantages of LED. And further illustrates some research results of LED lighting at home or abroad and illustrates significance of future development of LED lighting. Meanwhile, analysis of current research situation of LED drive power was done as well.So the main direction of the paper was determined.Second, a number of LED driver topologies were introduced in the round. The topology type is divided into non-switching power supply and switching power supply. The non-switching power supply includ DC drive LED mode, AC drive LED mode.The switching power supply driving circuit topology commonly used in LED lighting was detail decribed, which was devited into non-isolate type and isolate type. The design of constant current driver of LED was proposed combined with the characteristics of LED.The nonlinear characteristic of switching power supply caused low power factor. the problem is taken more and more attention. Power factor correction (PFC) will be the essential components of LED drivers. This paper made a detailed introduction of passive and active PFC, especially the type and control mode of active PFC.A favorable LED driver flyback switching power supply was designed based on the analysis in the previous. The main circuit, control circuit, feedback circuit and high frequency transformer were detail discussed in design. The common constant voltage control chip was realized the function of constant current by constant current feedback control circuit. A higher cost-effective switching power supply of constant drive was designed on basis of LED characteristics. Finally, the experimental waveforms of the whole design were given.The experimental results accord with parameter index and verify the correctness of theoretical analysis.