摘要
电力电子及开关电源技术因应用需求不断向前发展,新技术得出现又会使许多应用产品更新换代,还会开拓更多更新得应用领域。要求电子元件体积更小,耗能更低。开关电源作为电子设备中不可或缺得组成部分也在不断得改进,高频化、高效率、高可靠、低耗、低噪声、抗干扰和模块化等,成了开关电源得发展方向,这也标志着这些技术将不断地发展而变得越来越成熟和稳定,同时实现高效率用电和高品质用电得相互结合。
脉宽调制器SG3525具有欠压锁定、系统故障关闭、软起动、延时PWM驱动等功能,因而得到广泛应用。
本设计介绍了一种基于SG3525得半桥式开关电源变换器,对其各电路工作原理进行了分析,并设计了过流保护电路。为了提高效率,辅助电源采用了UC3843为主控芯片得反激变换器。为了减低输入电磁干扰,输入端设置了EMI滤波电路。对各参数进行了计算,通过实物制作与调试证明了方案得可行性。
该电源结构简单,思路清晰,运行稳定性好,有效降低了成本。
关键词半桥SG3525过流保护
Abstract
Technologyforpowerelectronicsandswitchingpowersupplyisgoingaheadcontinuouslyinpractice、Theemergenceofnewtechnologywillmakereplacementinmanyapplicationproductsaswellasopenupmoreandmorenewfields、Atthesametimeponentsarerequiredtohavethesmallervolumeandlowerlosses,asanimportantpartsofelectronicdevicespowersupplyisgettingsomeimprovements,forhigh-frequency,forhighefficiency,forhighreliability,forlowlosses,forsmallnoise,foranti-interference,formoduleandsoon、Thesearebeingadevelopmentdirectionforpowersupply,whichshowthatthesetechnologieswillbeemorematureandstable,itwillachievethebinabilitybetweenhigh-efficiencyandhighqualitytouseelectricenergy、
ThepulsewidthmodulatorSG3525hasbeenusedinvariousareasforitsfunctionssuchaslockingforthelackofpressure,closingsystemfault,softstarting,delayingPWMdriveandsoon、
Thisdesignintroducesahalf-bridgebasedonSG3525switchpowerconverte-r,theworkingprincipleofthecircuitisanalyzedanddesignedover-currentprotec-tioncircuit、Inordertoimproveefficiency,auxiliarypowerforthemainchipusedUC3843flybackconverter、Toreducetheinputofelectromagneticinterference,EMIinputfiltercircuitisset、eachparameterwascalculated,throughtheproducti-onandmissioningphysicalproofthefeasibilityoftheproject、
Thepowerstructureissimple,clear,runningstability,andeffectivelyreducingthecostofit、
Keywords:half-bridgeSG3525overcu