Design Of High-Power LED Aging Power Supplybased On STM32

The wide use of high-power LED(Light Emitting Diode)products is inseparable from its quality,and the expansion of the new use of led products needs its reliability.Wherein,the electrical aging characteristics of LED reliability are most important.The life of LED product is very long,so turn out a batch of continuous working for tens of thousands of hours with constant output led power supply is conducive to the test of led products and their reliability analysis.The electrical aging power supply of LED should have the function of high precision,constant output,no overshoot,and continuous adjustability.In this paper,the bridge switching power supply with PWM control circuit is used as the voltage output,coordinated with stm32f103rct6 to achieve double closed-loop control.Software and hardware are combined to achieve the constant output power supply,simultaneously,it made self-regulation come true.In the software,step by step rising the voltage is used,and Real-time monitoring of the signal is used to solve the switching power supply shooting.The power off is by the stm32 software interrupting,when the current of outside world is power off,STM32 immediately shut off the sg3525 chip,which made overshoot impossible.Digital to analog conversion chip and analog-to-digital conversion chip are used to monitor real-time power output,and the software and hardware coordinate to filter the data.Thus,stable and high precision output is obtained,and ensure the output voltage in software is according to the output value,so as to achieve continuous adjustable output.The developed products achieve the requirements of LED electrical aging test power supply,the output is accuracy within the range of less than 1 %,and constant output work more than 1000 hours is successed,without overshoot.