It is widely used in lighting equipment,computer equipment,communication electronic equipment,control equipment,household appliances and other electronic equipment.The miniaturization and modularization of the driving power supply is its development direction,which enables the driving power supply to enter a wider application field,especially the high-tech application field.In this paper,the push-pull converter is studied,and the push-pull transformer and filter inductor are magnetically integrated to reduce the volume of the driving power supply and improve the power density.The main research is as follows:(1)the advantages and disadvantages of the isolated switching power supply and the applicable occasions are studied.According to the design needs,the topology structure of the switching power supply studied in this paper is selected.(2)the working mode of the push-pull converter is analyzed,and the working principle of the voltage and current type push-pull converter is studied respectively.The working mode waveform is given,and the working state of the magnetic core of the push-pull converter is studied.(3)the power circuit and control circuit of the driving switch power supply of the push-pull converter topology are designed,the design parameters are calculated,the device selection is given,the control chip is selected,and the circuit design is completed.(4)the magnetic integration scheme of transformer and filter is presented.Under the condition of maximum,minimum and rated voltage input,the push-pull converter is simulated and verified.The experimental prototype is built and tested.Simulation verification and prototype test results show that the push-pull transformer and filter inductor decoupling magnetic integration effect is good,driving power supply efficiency is high,can be used in LED lighting drive.This paper has 33 figures,4 tables and 55 references. |