Multi-output LED Drive Power System Design

In order to solve the problems of unreliability and low power consumption of LED drive power supply, a new scheme is proposed by comparing with several existing typical modes. In this scheme, Buck closed-loop constant current control and PWM duty cycle double closed-loop dimming are adopted, and software is used to adjust PWM waveform. In the hardware part, the parameters of the back-end power supply are analyzed, and the parameter design and device selection of the Buck power loop are carried out. Then, a half bridge LLC resonant circuit based on APFC is established and simulated and analyzed. Finally, through the analysis of the output waveform of the system, the correctness of the scheme is verified.