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1、长春工业大学学士学位论文摘要本设计基于开关电源的工作原理,主体DC-DC变换电路采用Buck降压斩波电路,通过负载电流反馈,控制UC3843峰值电流模式控制器控制Buck变换器的占空比来实现负载电流的恒定。该设计电路主要包括单片机控制电路,DC-DC变换电路,稳流反馈电路,负载电流测量电路,基于PWM的电压输出DAC电路,基于A/D的键盘电路和过流保护电路。本数控直流恒流电源,输出电流范围0mA—1000mA,其步进值为10mA,效率较高。其中单片机采用了宏晶公司的增强型51单片机STC12C5A32S2,内部有8路10位A/D,有专用的SPI模块,可
2、以直接与ADC变换器通信,省去了软件模拟时序的麻烦。在软件部分,除了流程图以外,还分析了C语言编译原理。关键词:Buck,UC3843,反馈电路,数控直流恒流电源44长春工业大学学士学位论文AbstractSwitchingpowersupplywithpowersemiconductordevicesasswitches,thedutycyclemodulatedbycontrollingtheswitchoutputvoltage.Thepowertransistor(GTR),forexample,whentheswitchissaturated
3、conduction,thecollectorandemittervoltagedropclosetozeroatbothends;Whentheswitchisclosing,itscollectorcurrentiszero.Soitspowerconsumption,efficiencycanbeashighas70%to95%.Thelowpowerconsumption,heatsinkalsodecreases.Switchingpowersupplydirectlytotherectifiedmainsvoltage,filter,adj
4、ustment,andthenadjustthetubevoltagebytheswitch,nopowertransformerThedesignisbasedonswitchingpowersupplyworks,theDC-DCconverterwithBuckbuckchoppercircuit,throughtheloadcurrentfeedback,controlthepeakcurrent-modecontrollerUC3843Buckconverterdutycycletoachieveaconstantloadcurrent.Th
5、edesigncircuitincludesasinglechipcontrolcircuit,DC-DCconversioncircuit,constantcurrentfeedbackcircuit,theloadcurrentmeasurementcircuit,basedonthePWMvoltageoutputDAC,basedonA/Dkeyboardcircuitandover-currentprotectioncircuit.ThenumericalcontrolconstantcurrentDCpowersupply,outputcu
6、rrentrangeof0mA-1000mA,thestepvalueof10mA,efficiencyishigher.Microcontrollerwhichusesthecompany'senhancedmacrocrystal51MCUSTC12C5A32S2,internal8-channel10-bitA/D,adedicatedSPImodulecancommunicatedirectlywiththeADCconverter,eliminatingtheneedforsoftwaretosimulatethetimingofthetro
7、uble.Inthesoftwarepart,inadditiontoflow,italsoanalyzestheClanguagecompilertheory.朗读显示对应的拉丁字符的拼音 字典Keywords:Buck,UC3843,feedbackcircuit,NCdcconstantcurrentpowersupply朗读显示对应的拉丁字符的拼音 字典44长春工业大学学士学位论文目录摘要IAbstractII目录III第一章绪论11.1开关电源的基本构成1第二章硬件电路设计和原理22.1电源设计22.2主体变换电路的设计32.2.1模拟设计方
8、案32.2.2电力电子设计方案42.3PWM反馈控制电路设计82.4DAC转换电路设计152.