Design Of The Power Supply For LED

With the development of semiconductor technology, LED (Light Emitting Diode) illumination has played an important part in our life and industry. As a new solid-state Light source, it becomes the focus of the illumination area for its environmental protection, long life time, high efficiency photoelectric and so on. A large amount of money and effort have been invested to the research of LED and its driving power supply home and abroad.This paper first analyzes the light principle, volt-ampere, heat and optical properties of LED, chooses 1W white LED as the experimental object. After summarizing the LED drive circuit principle, it gives analysis, improvement design and simulation of the basic unit in the power source design from a design perspective.Secondly, the non-isolation LED step-down drive circuit is brought forward based on the chip AX2028. Also the detailed design of the MOSFET selection, sampling resistance and the inductance is deducted with the feasibility of the circuit analyzed from experiment.Thirdly, the isolation flyback type LED power supply is adapted for isolation LED drive occasion. The PWM circuit based on UCC28600 is optimized with a reasonable transformer structure. The constant current circuit with stable voltage and the feedback circuit is also designed based on AP4313, which keeps the power supply safely and stably.Finally, the illumination and heat dissipation of LED is analyzed, and the reasonable secondary light distribution and heat dissipation structure is proposed.