Design Of 120W RGBW LED Driver With WIFI Dimming Function

For the requirement of intelligent LED lighting,a RGBW LED driver which has the ability of WIFI dimming is designed.It can control RGBW LED to change their brightness and color of the light string through phone App.In order to meet the requirements of the power of various occasions,the design of the maximum output power is 120 w,and has the functions of adjustable output power,wireless remote control and dimming.The main works of the article are following:A three stage drive structure of "PFC + LLC resonant half bridge +BUCK" is adopted base on the comparison and analysis with several existing LED drive structures.The main cause of the EMI problem of LED power supply switch is introduced,and the filter is designed.The principle of PFC circuit in the critical conduction mode is introduced.The main parameters of PFC circuit are calculated and control circuit based on L6562AT is designed to improve the power factor of the drive;The principle of LLC resonant converter is introduced,the main parameters of LLC converter circuit are calculated and the control circuit based on L6599AT is designed.ZVS of the MOSFET and ZCS of rectifier diode are realized so that the switching loss of MOSFET switch and rectifier diode are reduced.The overall efficiency of the converter is improved;The principle of BUCK buck regulator circuit is introduced.The main parameters is calculated and BUCK constant circuit based on LM3404HV is designed.Four outputs that provide a constant current for the WIFI control of RGBW are obtained;The principle of PWM dimming is introduced.The microcontroller circuit based on the STM8S005K6 and WIFI module based on USR-WIFI232-T are designed.The PWM dimming controlled by WIFI is realized.The experimental results show that the EMC of driver achieve the EN55015 standards,power factor achieve 0.95 in the case of above half load;Efficiency achieve 90%in the case of full load;ZVS and ZCS are realized;Four roads of constant current output are realized in the the case of full power 120W;PWM dimming is realized which controlled by WIFI and the range of dimming is 0%-100%.The goal of design is achieved.