小灵通基站的开关电源设计

中文摘要

开关电源是应用于广泛领域的一种电力电子装置。它具有电能转换效率高、体积小、重量轻、控制精度高和快速性好等优点，在小功率范围内基本取代了线性电源，并迅速想大功率范围推进，在很大程度上取代了晶闸管相控整流电源。可以说，开关电源技术是目前中小功率直流电能变换装置的主流技术。

本文首先描述了开关电源的发展，对目前出现的几种典型的开关电源技术作了归纳总结和分析比较，在此基础上指出了开关电源技术的发展状况和开关电源产品的发展趋势。并且对开关电源的发展史、应用范围、主电路的选择、控制方法作了简要的介绍。

在综合分析各种控制方法和元器件性能后，设计了一个开关电源适配器，将输入为90-270V、50/60Hz的交流电输入转换成27V、3A的直流电输出，使其能提供给小灵通基站一个稳定输入，并具有电网掉电检测功能。在设计中主要采用了脉宽调制（PWM）、全桥整流、自锁保护等技术，应用了控制芯片SG6848做为PWM控制芯片，对变压器次级线圈采用堆叠式绕法，改进光耦反馈电路的选择，使电路能达到所需基本要求同时，力求稳定、高效。此开关电源在一般的开关电源基础上多了一种电网掉电检测功能，这是此电源的一大特点。在设计最后针对布板问题还分析改进了电磁兼容性问题。在整个设计电路完成后，对电路进行了测试，并对测试结果进行了分析。

关键词：开关电源、PWM、SG6848、电磁兼容

 

 

 

 

 

 

 

 

 

The design of CS’switch power supply

Abstract

The switch power supply is a kind of electric power electronics which applies in the extensive realm to be used.It has an electric power conversion's efficiency high, the physical volume is small, the weight is light, the control accuracy is high with fast etc. advantage, within the scope of small power replaced line power supply, and in high-power scope propulsion quickly, to a large extent,it replaced the thyristor phase - controlled rectifying power supply .We can say, the switch power supply technique is the essential technique which wins small electric power transformation of the power direct current to equip currently.

This text described the development of switch power supply first, to a few kinds which appear currently typical model of the switch power supply technique made to induce summary and analysis comparison, pointing out the development trend of the technical development condition of the switch power supply and switch power supply product on this foundation.And introduce the    switch power supply’s phylogeny,application, main electric circuit of power supply and controled a method .