基于tl431的反激式开关电源设计学士.doc

淮北师范大学2014届学士毕业论文基于TL431的反激式开关电源设计PAGE\*MERGEFORMATIV基于TL431的反激式开关电源设计张明志淮北师范大学物理与电子信息学院235000摘要本设计是基于TL431设计反馈电路的一种反激式开关电源。反激式开关电源的优点是其电路简单、体积小便于携带、输出电压稳定性高。随着信息技术的迅速发展，反激式开关电源适用于小功率场合且易于推广使用。本电源设计主要讲述了开关电源的基础知识和反激式开关电源的基本原理设计、集成芯片的使用和外围电阻的确定、由TL431和PC817构成的反馈电路及课题研究得出的结果。文讲述了利用反激式开关电源的基本原理设计出了供非常规用电设备使用的非常规开关电源，课题研究结果得出它的输出电压稳定性高，且输出电流大，具有实用性。同时，我们还可以根据本论文的设计原理通过改变占空比和芯片外围电阻值制作不同输出的开关电源（输出功率要在100W以内），供应日常生活的小功率电器使用。关键词开关电源；反激式；TL431；UC3842；反馈电路TheflybacktypeswitchpowersupplydesignbasedonTL431ZhangMingzhiSchoolofPhysicsandElectronicInformation,HuaiBeiNormalUniversity,AnhuiHuaibei,235000AbstractAhighpreciseandreliablesingle-endedflybackswitchingpowersupplywasdesignedandmadeinthispaper,whosecurrentcontrollerconsistedofalinearphotoelectriccouple.Theclosed-loopfeedbackofTL431wasusedtorealizeswitchingpowersupply’sstableequilibrium.Comparedwithgeneralswitchingpowersupply,thepower’shadbeenwiththeadvantagesofhighswitchfrequency,smallswitchloss,highreliabilityandsoon.WiththerapiddevelopmentofInformationTechnology,theflybackswitchingpowersupplywasusedwidelyinlowpowerapplication.Thedesignandapplicationofanewsingle-outputsingleflybackswitchingpowersupplywasproposedinthispaper.Thepaperhadbeenanalyzedflybackswitchingpowersupplyoftheirworkingprincipleandthebasicknowledge,andintroducedafewmajorchipfunctionsandtheuseofthepinandtheresearchresults.Ofcourse,therealizationofthefeedbackcircuitbasedonTL431andPC817waspresentedinthepaper.Anunconventional-outputandsingle-endedflybackswitchingpowersupplywasdesignedandmadeinthispaper,whosethebasicprincipleconsistsoftheflybacktypeswitchpowersupply.Thearticlehadbeenintroducedanunconventionalflybackpowersupply.Theflybackpowersupplyhadbeenwiththeadvantageofoutputcurrentlargeandstablevoltage.Concurrently,wecanalsousethesmallpowerelectricalappliancesinthedailylife,whichwewillmakeaccordingtotheprincipleoftheflybackswitchingpowersupplyinthispower.KeywordsSwitchingpowersupply;Flyback;TL431;UC3842;feedbackcircuit目次1绪论…………………………………………………………11.1开关电源简介