| High-power LED is a new generation of green light source. It has the characteristics of energy saving and high efficiency. The current LEDs are mainly driven by specially designed constant current driver. It is not as good as the traditional power supply in reliability, and its design is more complex. This project is mainly to study the system reliability and efficiency. LED drivers are with two-stage structure, the first stage using constant voltage power supply, whose technology is mature; the last stage, the linear constant current drive mode, enables each branch of the LED to have a constant current.This article describles the topology of LED driver and its current development. It is proposed by using constant voltage power supply and linear constant current module to drive LED. In linear constant current part, the author introduced the principle of linear constant current driver, described how to design the linear constant current module and designed it with the chip of MAX16836. The actual test result shows that the constant current effect is good and has a high efficiency. The value of the constant current is 300mA, and the maximum efficiency can reach 97.5%. In DC/DC step-up regulator part, the author intrduced the principle of switching power supply, described how to design a DC/DC step-up regulator and the compensation network. The author has calculated the main components parameters of the converter and the feedback compensation network, simulated them and gave the results of the simulation. At last, the DC/DC convertor was tested and the results shows that the constant voltage effect is good and has a high efficiency. The constant output voltage is 36V, and the regulation accuracy is 0.378%, and the efficiency of system is 90.6%, which are consistent with the simulation and calculation results.Based on the above mentioned programs, the author has designed and made the self-adaptive lighting system and the intelligent control system about color temperature. |
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