The Study Of The Key Technologies Of The LED Driver

With the global environment getting worsen, and energy crisis worsens, humans began to get more and more attention to environmental protection and energy-saving technologies. As the Light Emitting Diode (LED) in the fifties of the last century has been found, Extensive research been taken in the application of LED in general lighting field. LED luminous efficiency (lm/W) also increased year by year, declining prices, which have broadened their scope of use.Because of DC current source driver, but the grid provide AC voltage source, the LED driver should have the ability to transfer the AC power supply to DC constant current supply with less power loss.Compatible with TRIAC dimming, cost control, multiple output constant current characteristic.These are the problems that LED driver face.This make LED driver technology to become a hot topic of power electronics in recent years.In this paper, there are two points, The first focus on low-power LED driver, mainly for indoor applications, especially in the field of civil LED lighting, research aim is to reduce the cost and board volume of small power LED driver, the paper pay a lot of attention on Primary Side Regulation(PSR) constant current, PFC, triac dimming. This section first analyzes the theory and the principles of the PSR circuit, and produced two prototypes were compared. The one is PSR circuit,the other is SSR circuit. In order to study the SCR dimming circuit, the authors also used the MP4030chip to produced a18W Dimmable LED Driver, waveform and the performance of the circuit been analysis.The second point is the study of high-power LED driver, there are two main topics, the one is to improve the efficiency, and the second is to improve the performance of multiple outputs. First analysis commonly used in high-power circuits the LLC circuit works, the circuit working condition of each time period, the soft switch works and conditions. The three key parameters in the allocation and LLC optimization and improvement. Then conducting experiments, the experimental results indicate that the efficiency of the circuit is optimized. This paper then analyzes LLC multiple output circuit principle and parameter design method, using PSIM software simulation to illustrate the feasibility of the design method. And production in the final sample, A180W six output routing LED driver.Using the L6562and L6599chip.The analysis the derived parameters applied in the circuit, indicating the correctness and feasibility of the design.