LED street light is an important application in LED lighting. Under the premise of energy saving and power saving, due to the traditional high-pressure sodium lamp or halogen lamp, the luminous efficiency is far less than that of high-power LED, and the trend of LED street lamp replacing traditional street lamp is more and more obvious. With the rise of low-power LED street lights, solar street lights have become more feasible. The low power consumption feature greatly reduces the cost of the battery and solves the problem of night lighting in remote areas. In the market, the design of LED street lamp power supply has quite a variety of designs. The early design has paid more attention to the pursuit of low cost. From simple checkerboard connection to design that only regulates the current without adjusting the voltage, it is the mainstream. . And with the growing understanding of LED. And new solutions from many IC design companies have been released. In the near future, the consensus has gradually formed, and the high-efficiency and high-reliability power supply design is the most important. In recent years, Liyi Technology has released a series of driver ICs for LED lighting. It has also been concerned about the development of LED street lamps. This paper is mainly for the application of several different LED street lamps, proposes a suitable architecture, and analyzes the advantages and disadvantages. Let readers find the most suitable solution according to their company's situation and the scope of application of the designed street lamp. The same architecture can also be used in the design of other high-power luminaires. 1. Direct AC input, constant current control for 6 strings of LEDs Among the following solutions, this should be the most efficient and lowest cost circuit. The output voltage is adjusted directly by the back-to-back control of the primary side by the Photo-coupler. Compared to other traditional solutions, one less switchinglose. The CSpin voltage is fixed at 0. 25V, and the current is controlled for the 6 strings of LEDs. The IC will detect the position of each string of FBs, and fix the string with the lowest voltage, that is, the highest sum of Vf, at 0.5V. At this time, due to the difference in the sum of the LEDVf values ​​of the strings, the excess voltage caused by the Vf difference will fall on the MOS, causing some loss. If it is a general LED for Vf after BIN, the loss should be controlled within 2%. Less than the usual switchinglose. If you use the primary side of the LLC architecture, you have the opportunity to make the overall power efficiency close to 90%. Based on the current stage, LED factories are not inclined to provide high-power LEDVf sub-Bin services. Therefore, it is necessary for the user to adjust the sum of the LEDs of each string, which causes troubles in mass production. At present, this method is more suitable for programs that have extreme pursuit of efficiency, especially those that are priced by the amount of power saving. (Click on the image to view the original HD picture) Advantages: high efficiency and low cost Disadvantages: AC input, the design of the primary side is more complicated, and the power efficiency is related to the difference of the Vf of each string. Suitable for street lamps that pursue high efficiency Pd Fast Charger,45W Usb-C Charger,Mobile Phone Fast Charger Usb-C,Apple Phone 12 Charger Guangdong Mingxin Power Technologies Co.,Ltd. , https://www.mxpowersupply.com