15V开关电源设计毕业论文.docx

15V开关电源设计 摘 要 开关电源在计算机技术、通信技术、自动化仪表以及普通家电等方面应用广泛。随着当代人们生活水平的提高，人们对开关电源的要求越来越高。开关电源因其具有效率高、体积小、重量轻、使用方便等显著优点，已经逐步取代了传统的效率低、体积大、笨重的线性电源。目前，随着电源技术的蓬勃发展，开关电源正朝着高频化、集成化等方向迈进。 本论文利用反激式变换器的特点，设计了一种基于UC3842芯片的开关电源系统。论文首先介绍了开关电源设计的理论知识，主要包括开关电源基本的工作原理，几种常用的开关电源拓扑结构介绍，完成了开关电源拓扑结构的选取。接着详细阐述了开关电源系统的整体设计方案，主要包括主电路的设计和控制电路的设计。主电路的设计，包括EMI滤波电路、输入输出整流滤波电路、功率开关电路、高频变压器等。控制电路的设计，完成了UC3842型电流模式PWM控制电路及其外围电路的设计。最后绘制了完整的电路原理图，并通过MATLAB的Simulink模块对所设计的开关电源电路进行了实验仿真，结果验证了本文所设计开关电源电路的正确性和可行性。 关键词 开关电源，15V，UC3842，PWM  ABSTRACT In computer, communications, automation instrument and switch power supply widely used household appliances, etc. As people living standard rise, people of switch power supply put forward higher requirements. Switching power supply because of its high efficiency, small volume, light weight, easy to use and other significant advantages, has gradually replaced the previous low efficiency, big volume, heavy linear power supply. Over the years, with the vigorous development of power electronic technology, especially the great development of semiconductor technology, will be the performance of the switch power supply referred to a higher level. The core of switching power supply unit, control circuit to realize integration is one of the development direction of switching power supply, in the process, smaller volume, less electromagnetic pollution, has reliable overvoltage and overcurrent protection circuit of the technology is in rapid development. This thesis is based on the UC3842 chip 15 v low power high frequency switch power supply system design, the paper first completed the selection of switch power supply topology structure, expounds its working principle in detail, then completed the UC3842 type current mode PWM control circuit, auxiliary circuit design, as well as the high frequency transformer design work, finally draw a complete circuit schematic diagram, through MATLAB Simulink module for the design of switch power supply circuit simulation, results show