河南科技大学（论文）开关电源的毕业设计摘要电源是实现电能变换和功率传递的主要设备。在信息时代，农业、能源、交通运输、通信等领域迅猛发展，对电影产业提出个更多、更高的要求，如节能、节材、减重、环保、安全、可靠等。这就迫使电源工作者不断的探索寻求各种乡关技术，做出最好的电源产品，以满足各行各业的要求。开关电源是一种新型的电源设备，较之于传统的线性电源，其技术含量高、耗能低、使用方便，并取得了较好的经济效益。UC3842是一种性能优良的电流控制型脉宽调制器。假如由于某种原因使输出电压升高时，脉宽调制器就会改变驱动信号的脉冲宽度，亦即占空比D，使斩波后的平均值电压下降，从而达到稳压目的，反之亦然。UC3842可以直接驱动MOS管、IGBT等，适合于制作20～80W小功率开关电源。由于器件设计巧妙，由主电源电压直接启动，构成电路所需元件少，非常符合电路设计中“简洁至上”的原则。设计思路，并附有详细的电路图。关键词：开关电源，uc3842，脉宽调制，功率，IGBTI河南科技大学（论文）SWITCHINGPOWERSUPPLYDESIGNBASEDONUC3842ABSTRACATPoweristoachievepowerconversionandpowertransmissionmajorequipment.Intheinformationage,agriculture,energy,transportation,communicationsandotherareasPowerofthefilmindustrymakeagreaterandhigherrequirements，suchasenergy,materials,weightreduction,environmentalprotection,safetyandreliability.Thishasforcedthepowerworkershavebeenexploringthetechnologyforavarietyofruralcustoms,thepowertomakethebestproductstomeettherequirementsofallwalksoflife.Switchingpowersupplyisanewtypeofpowersupply,comparedtotraditionallinearpowersupply,hightechnology,lowenergyconsumption,easytouse,andhasachievedgoodeconomicresults.UC3842isanexcellentcurrent-controlledpulsewidthmodulator.Ifforsomereason,theoutputvoltageincreases,thepulsewidthmodulatordrivesignalwillchangethepulsewidth,thatis,thedutycycleD,sothattheaveragevoltagedropafterthechoppertoachievetheregulatorend,andviceversahowever.UC3842cancontroldirectdriveMOS,IGBT,etc.,suitablefortheproductionof20~80Wlow-powerswitchingpowersupply.Asthedeviceiscleverlydesigned,launchedbythemainpowersupplyvoltagedirectlytoformcircuitcomponentsrequiredforasmall,veryconsistentwithcircuitdesign,"simplicityfirst"principle.KEYWORDS:SwitchingPowerSupply，uc3842，PWM，power，IGBTII河南科技大学（论文）目录前言............................................................1第1章开关电源的简介............................................21.1开关电源概述.............................................21.1.1开关电源的工作原理................................21.1.2开关电源的组成.................................