半桥式开关电源设计

洛阳理工学院毕业设计（论文）I半桥式开关电源设计摘要随着电子技术的高速发展,电子系统的应用领域越来越广,电子设备的种类也越来越多,电子设备与我们的工作、生活的关系日益密切。近年来,随着功率电子器件(如IGBT、MOSFET)、PWM技术以及电源理论的快速发展,新一代的电源电路开始逐步取代传统的电源电路。该电源电路具有体积小，控制灵活方便，输出特性好、纹波小、负载调整率高等显著优点。由于开关电源中的功率调整管工作在开关状态，具有功耗小、效率高、稳压范围宽、温升低、体积小等突出优点，因此在通信设备、数控装置、仪器仪表、视频音响、家用电器等电子电路中得到广泛应用。开关电源的高频变换电路形式很多,常用的变换电路有推挽、全桥、半桥、单端正激式和单端反激式等形式。本论文采用双端驱动集成电路——TL494输的PWM脉冲控制器设计音响设备供电电源，利用BJT管作为开关管，可以提高电源变压器的工作效率，有利于抑制脉冲干扰，同时还可以减小电源变压器的体积。关键词：TL494，PWM，半桥式电路，开关电源洛阳理工学院毕业设计（论文）IIDesignofHalfBridgeSwitchingPowerSupplyABSTRACTWiththerapiddevelopmentofelectronictechnology,electronicsystems,moreandmoreextensiveapplications,thetypesofelectronicequipment,moreandmoreelectronicequipmentandpeopleworkandlivecloserandcloser.Inrecentyears,withthepowerelectronicdevices(suchasIGBT,MOSFET),PWMswitchingpowersupplytechnologyanddevelopmentofthetheory,anewgenerationofpowerbegantograduallyreplacethetraditionalpowersupplycircuits.Thecircuitissmall,flexibletocontroltheoutputcharacteristicsofagood,ripple,loadadjustmentrateandsoon.Switchingpowersupplyinthepoweradjustmentcontrolworkintheoffstate,withlowpowerconsumption,highefficiency,widevoltagerange,lowtemperaturerise,andotheroutstandingadvantagesofsmallsize,thecommunicationequipment,CNCequipment,Instrumentation,videoaudio,homeappliancessowidelyusedinelectroniccircuits.Highfrequencyconverterswitchingpowersupplysomanyformsofcommonlyusedwithpush-pullconverter,fullbridge,halfbridge,single-endedforwardandtheformofsingle-endedflyback.Inthisthesis,two-sidedriverIC-TL494PWMpulseoutputofthecontrollerdesigncaraudiopowersupplyinuseasaswitchMOSFET,canimprovetheefficiencyofthepowertransformer,isconducivetoimpulsenoisesuppression,butalsocanreducethesizeofthepowertransformer.KEYWORDS:TL494,PWM,Halfbridgecircuit,Switchingpower洛阳理工学院毕业设计（论文）III目录前言..................................................................................................1第1章开关电源基础技术...............................................................21.1开关电源概述.......................................................................21.1.1开关电源的工作原理.................................................21.1.2开关电源的构成.........................................................31.1.3开关电源的特点.........................................................41.2开关电源典型结构...............................................................41.2.1串联开关电源结构.....................................................41.2.2并联开关电源结构.....................................................51.2.3正激式结构.................................................................61.2.4反激式结构.................................................................71.2.5半桥型结构.................................................................81.2.6全桥型结构.................................................................91.3开关电源的技术指标.........................................................10第2章半桥变换电路.....................................................................122.1半桥变换电路工作原理.....................................................122.2半桥变换电路的应用.........................................................132.3半桥变换电路中应注意的问题..........................................142.3.1偏磁问题...................................................................152.3.2用作桥臂的两个电容选用问题................................152.3.3直通问题...................................................................162.3.4半桥电路的驱动问题...............................................172.4双极结型晶体管.................................................................172.4.1结构和定义...............................................................172.4.2三极管的特性曲线...................................................19第3章脉宽调制芯片TL494应用分析.........................................233.1TL494管脚图.......................................................................233.2TL494内部电路介绍...........................................................23洛阳理工学院毕业设计（论文）IV3.3TL494管脚功能及参数......................................................243.4TL494脉宽调压原理..........................................................26第4章TL494在DC-DC变换中的应用...........................................284.1音响设备电源简述.............................................................284.2音响供电电路分析.............................................................28第5章PCB设计制作....................................................................315.1PCB的设计制作步骤..........................................................315.2注意事项.............................................................................335.2.1特殊元件的布局.......................................................335.2.2布线处理...................................................................34结论................................................................................................35谢辞................................................................................................36参考文献..........................................................................................37附录................................................................................................39外文资料翻译......................................