Design Of Adjustable Active And Negative Switching Power Supply Based On APFC

Nowadays, with the rapid development of electronic communication and networkinformation industry, power electronic equipments such as switching power supply havebeen widely used and developed. This paper combines the embedded developmentboard project in the research group and in accordance with the electrical requirements of1A maximum input current of the development board, considering the practicality andsimplicity of the power circuit, this paper mainly studies AC to DC multi-outputpositive and negative switching power supply with the function of APFC. To facilitatethe design of the overall structure and consider the different functions of each circuitmodule, the power is divided into three parts, namely the part of Active Power FactorCorrection, fly-back DC converter and linear regulator output voltage regulation. Theinput of the power is AC220V, Frequency at 50Hz, and the output voltage is DC 0V ~±12V, with the maximum supply power is 50W.Design methods of the overall power circuit is: the APFC part of the first part ofthe power circuit uses Boost topology circuit structure, with the regulation and controlmethod of PWM control. The chip of the drive control is Infineon ICE1PCS01, ofwhich the biggest advantage is the double loop control of current and voltage. Since itdoesn't use multiplier feedback structure, but regulates the driving duty throughcommon work of current peak detection and output voltage feedback, therefore, theexternal circuit is very simple. APFC circuit part has increased a high input power factor,up to 95%, greatly reducing the disturbance to the power net. The secondary part of thepower converter circuit uses single fly-back circuit based on UC3842, and has realizedvoltage transform from DC 400V voltage to the stable output of±32V DC voltage bythe adjustment of the transformer and duty. Finally, through the linear voltage regulatorand variable resistor, the power has achieved a variable target voltage.The principles and characteristics of the key circuits are analyzed in this paper, andthe primary circuits towards different function circuits besides their parameters areestablished in this paper. In the end, the key circuits have been simulated by usingMultisim and Pspice software. And through the analysis of the simulation results, thedesign of the switching power supply is approved to be qualified.