Study & Development Of 48V/25A Communication High Frequency Switching Power Supply

Some of studys of the 48V/25A high-frequency switching power supply which is used in the communication systems are introduced in the thesis.The main contents are follows:Firstly,the main circuit of the power supply is designed,and the ZVS technology is appled in the full-bridge circuit in the equipment.Secondly, the control circuit,the driver circuit, the protect circuit of the power supply are analyzed and designed. Its control circuit is centered on UC3875 and AT89C52, uses a double control that is composed of analog and microprocessor-based regulation to realize the function of voltage-stabilization and current-limited. And the adjustment is designed in the closed loop control systems.By the data collected and disposed ,the supervise and control unit realized not only the fuction of control,but also the functions of the on-line measure and modification,the display,the communication,and so on. The intelligentization is primary realized in the power supply.Thirdly,The technology of the active power factor correction is studied in the thesis.The transfer function of the Boost circuit is acquired based on the model of the small signal, by which the principle of the active power factor correction based on the Boost circuit is understood.And the Boost ciucuit is simulated by the MATLAB.Lastly, A few measures of current sharing are studied and compared. The means of the most current automatic current sharing is introdued particulary. Based on the means of the averaged current automatic current sharing ,the circuit of the applied averaged current automatic current sharing is designed and the result of the current sharing is good by the examination.