资源描述：
《燕山大学eda课程设计数字跑表》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、一、设计题目及要求设计题目：数字跑表要求：1具有暂停，启动功能；2具有重新开始功能；3用六个数码管分别显示百分秒，秒和分钟。二、设计过程及内容总体设计：第一，对于要实现的暂停、启动和重新开始功能，需要有一个控制模块完成相关控制。第二由题意可知需要一个分频模块，将实验箱提供的频率转换为100HZ即数字跑表百分秒的频率。第三是计时模块，完成跑表的百分秒、秒和分钟的计时功能。第四由于实验箱提供的数码显示是扫描显示，这就需要一个选时模块。第五部分则是显示模块。详细设计过程：根据要求，将设计分成五个模块：1、控制模块：使跑表具有启动、暂停及重新开始的功能；2、分
2、频模块：将实验箱所提供的频率转换为设计题目所需要的100HZ的时钟脉冲；3、计时模块：进行百分秒、秒、分的计时，并且将当前时间输出给选时模块；4、选时模块：从计时器得到当前时间输出给显示模块；5、显示模块：通过数码管显示时间。总图如下：meetthestandardrequirements.Postweldheattreatmentofpipesafterheattreatment,hardnesstestsshouldbeconducted,hardnesstestsamplingofnotlessthan10%,hardness120%,15CrM
3、ohardnessofcarbonsteelpipeshallbelessthanbasemetalsteelafterheattreatment,hardnessshouldnotbegreaterthantheparentmaterialof125%.Rateofpipelinenondestructivetestingshallbecarriedoutaccordingtothedesignrequirements,nonodesignrequirementstheSH3501-2002table10"percentageofradiograph
4、icexaminationofweldedjointsandacceptablelevel",andfixednumbernotlessthanthetotalnumberof40%weldinspection.Thisprojecthasawallthicknessof32mm20#steelhighpressuretube,x-rayscannotpenetrate,thesituationmaynotallownon-destructivetestingbyγ-ray,usedweldbackingandtwo-layerweldsbeforef
5、illedbyxraydetectionmethod,theotherlayerbyultrasonicdetectormethod.Shouldbeconsistentwithexistingnationalstandardsforradiographictestingofthe...Gastankusedchainforthisprojectpromotedtheupsidedownconstruction.Chainreversalinstallationmethodshowninthefollowingfigure:weldersWelders
6、andweldingmethodstoparticipateinthisprojectshouldbeinaccordancewiththeMinistryofpersonnelissuedbytheboilersandpressurevesselswelderexaminationrulesforqualificationexamination,afterpassingthequalificationcertificateofweldingwork.Tankweldingmanualarcwelding,automaticwelding.Manual
7、arcweldingcompanyhasanumberofexcellentwelder,tookpartinallkindsoflarge,mediumandsmallstoragetank,pressurevesselwelding,withrichexperience,manualweldingcharacteristicsarenotsubjecttolocationrestrictions,weldingdeformationeasytocontrol.Thisengineeringweldingconstructionofshieldedm
8、etalarcweldingmethods.9仿真波形：第一个模块：控制模块控制模块主要运用了
