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1、摘要本设计以AT89S52单片机为核心控制芯片,实现数控直流电源功能的方案。设计采用8位精度的DA转换器DAC0832、三端可调稳压器LM350和一个UA741运算放大器构成稳压源,实现了输出电压范围为+1.4V~+9.9V,电压步进0.1V的数控稳压电源,最大纹波只有10mV,具有较高的精度与稳定性。另外该方案只采用了5个按键实现输出电压的方便设定,具有设定值调整,微调(步进量0.1),粗调(步进量1)三种调整功能,显示部分我们采用了三位一体的数码管来显示输出电压值。我们自行设计了12V和5V电源为系统供电。该电路的原理是通过MCU控制DA的输出电压大小,通过放大器放大,放大后的电压
2、作为LM350的参考电压,真正的电压还是由电压模块LM350输出。利用5个按钮调整电压、并且通过共阴极三位一体LED显示输出的电压值。设计使用3三位一体数码管,可以显示三位数,一个小数位,比如可以显示5.90V,采用动态扫描驱动方式。与传统的稳压电源相比具有操作方便,电源稳定性高以及其输出电压大小采用数码显示的特点。关键词:数控,步进,三端可调稳压器37ABSTRACTThedesigniswiththeMCUAT89S52forthecorecontrolchip,whichcarryouttheprojectthatthefunctionofthenumbercontrolsthe
3、directcurrentpowersupply.DesignedwiththeprecisionofeightDAconverterDAC0832,three-adjustableregulatorsLM350andaUA741OperationalAmplifiersconstituteRegulatorssource,theoutputvoltagerangeof+1.4V~+9.9V,0.1VvoltagestepNCRegulatorsPower,ithaswithhighprecisionandstabilityandonlyhavethebiggestrippleof10
4、mV.Meanwhile,theprogramusedonlyfivekeystoachievetheconvenienceoftheoutputvoltagesetting,withsettingvalueadjustments.Ithasthreekindsofadjustfunction,whichcancarryoutmicro-adjustment(Steppingvolume0.1)andthecoarseadjustment(Steppingvolume1).Theshowpartwehaveadoptedathree-dimensionaldigitalpipetosh
5、owtheoutputvoltagevalue.Andwedesignedthe12Vand5Vpowersupplysystemforelectricity.TheprincipleofthatelectriccircuitwasthattheoutputvoltagesizewhichpassestheMCUtocontrolDA,passingtheamplifieramplification,andthevoltageisthereferencevoltageoftheLM350.AndtherealvoltageisstilltheLM350outputsarefromthe
6、voltagemoldpiece.Makinguseoffivebuttonstoadjustmentvoltages,andpassthetotalcathodeChristianTrinityLEDtodisplaytheoutput'svoltage.InthisdesignIused3piececodetubes,whichcanshowthreepositionnumbers,oneofthemisafractionposition.forexample,itcanshowa5.90Vs.InthisdesignIadoptthescantodrivewayisdynamic
7、statesweep.Withtraditionalsteadypresspowersupplytocomparetohaveanoperationconvenience,thepowersupplystabilityhighcharacteristics,itsexportationelectricvoltagesizeadoptionfiguresshow.Keywords:NumericalControl,Stepping,Three-a