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1课程综合实验课程名称学生姓名学号系、专业指导教师2018年12月20日2ContentIntroducingcircuitsimulationsoftwarePartA—WaterLevelAlarmSystemWithThermostat1.DesignRequirement2.WaterLevelAlarmSystem2.1Component2.2Circuitmoduleanalysis2.3experimentalresult3.Watertemperaturesystem3.1Component3.2Introduce7447Nandoperations3.3circuitdiagram3.4Resultdemonstration4.ConclusionPartB—CounterandDACDesign1.Requirement2.Circuitdiagram2.1Counter2.2experimentalresult3.Conclusion3Introducingcircuitsimulationsoftware：MultisimisaWindowsbasedsimulationtoolintroducedbytheU.S.NationalInstrumentation(NI)Co.,Ltd,whichissuitableforthedesignofboard-levelanalog/digitalcircuitboards.Itcontainsthegraphicinputofcircuitschematicdiagram,theinputmodeofcircuithardwaredescriptionlanguage,andhasrichsimulationanalysisability.EngineerscanuseMultisimtobuildcircuitschematicsinteractivelyandsimulatecircuits.Multisimrefinesthecomplexityofspicesimulationssothatengineerscanquicklycapture,simulate,andanalyzenewdesignswithouthavingtounderstandspicetechnology,makingthemmoresuitedtoelectronicseducation.ThroughMultisimandvirtualinstrumentationtechnology,PCBdesignengineersandelectronicseducatorscancompleteacomprehensivedesignprocessfromtheorytoschematicdrawingcaptureandsimulationtoprototypedesignandtesting.4PartA—WaterLevelAlarmSystemWithThermostat1.DesignRequirementItisrequiredtodesignawaterlevelalarmsystemthatcanbeusedtomonitortheriver(s)waterlevelandwatertemperature.Theinputvoltagesavailabletothealarmsystemaredefinedtobeintherangeof0to1voltsfromthewatersensors.ThealarmsystemshouldusefourLEDstoindicatethefollowingvoltagelevelsatitsinput4,6,8and10Volts.WhenalltheLEDsareon,thesystemshouldgenerateasquarewaveaudibletonewithapeaktopeakvalueof5Voltsfor10seconds.ThedesignshouldalsouseathermostattogaugethetemperatureanddisplaythetemperatureonaSevenSegmentDisplay.▪Whenthewatertemperaturereachesreaches1°C,display1▪Whenthetemperatureofthereaches5°C,display5Powersuppliesavailableare+/-12volts2.WaterLevelAlarmSystem52.1Component（1）Powersupply（2）Resistance（3）741amplifier（4）LED（5）Electriccapacity（6）Buzzer（7）555Calculagraph（8）NOTgate（9）NANDgate（10）ANDgate（11）Oscilloscope2.2Circuitmoduleanalysis（1）SenorArea-WaterLevelThiscircuitmodulerepresentsthelevelofthewaterlevel,andtheoutputsignalsofdifferentwaterlevelsaredifferent.6(2)AmplifierSometimesthevoltageandcurrentsignaloutputbythesensormaybesosmallthatitisdifficulttodetectthevariationinthesignalprocessing,soitisnecessarytoamplifythesignalwithanamplifiertoobtainthecurrentandvoltagesignalsmoothly.（3）LEDdisplayWhenthewaterlevelis0,allfourLEDarenotbright.7Whenthewaterlevelis40%,theLED1ison,andtherestoftheLEDisnot.Whenthewaterlevelis60%,LED1andLED2arebright,andtherestoftheLEDisnotbright.8Whenthewaterlevelis80%,theLED1,LED2andLED3arebright,andtherestoftheLEDisnotbright.WhenfourLEDlights,thewaterlevelreachesitsmaximum.9（4）555timerThe555timerisanintegratedcircuitchipthatisoftenusedasatimer,pulsegenerator,andoscillatingcircuit.555canbeusedasadelaydevice,triggerorstartingelementinacircuit.The555timerinthisexperimentisusedasthepulsegenerator.Thefrequency,orrepetitionrate,oftheoutputpulsesisdeterminedbythevaluesoftworesistors,R1andR2andbythetimingcapacitor,C.Thedesignformulaforthefrequencyofthepulsesis:TheHIGHandLOWtimesofeachpulsecanbecalculatedfrom:Thedutycycleofthewaveform,usuallyexpressedasapercentage,isgivenby:AnalternativemeasurementofHIGHandLOWtimesisthemarkspaceratio:Beforecalculatingafrequency,itisusualtomakeR1=1kΩbecausethishelpstogivetheoutputpulsesadutycyclecloseto50%,thatis,theHIGHandLOWtimesofthepulsesareapproximatelyequal.Finally,igetR111Ω10（5）ComparatorsFrom741op-amps,configuredascomparators,areusedtocomparetheoutputvoltagefromtheinvertingamplifier.Thecomparativevoltageisobtainedbyavoltagedropbetween2resistors,suchthatthe4V,6V,8Vand10Vreferenceareobtainedfroma12Vsupply.Atthesametime,theoscilloscopeshowsthechangeofwaveform.2.3experimentalresult（1）Waveformdiagramwhenthewaterlevelisnormal11（2）WaveformdiagramwhenthewaterlevelisabnormalTheBuzzerstartsworking.3.Watertemperaturesystem3.1Component(1)Powersupply(2)7447N(3)Resistance3.2Introduce7447NandoperationsThemainfunctionof7447istooutputlowleveldrivedisplaycode,whichisusedtopromotethecommonanode7segmentLEDdigitaltubetodisplaythecorrespondingdigital.ThemainfunctionoftheIC,7447istoconvertaBCDcodeintoa7segmentLEDdigitaltubeanddrivetheIC,7447tooutputalowleveldrivedisplaycode.Inthe7447N,A,B,CandDareequivalenttobinaryinput,Thesefourswitchesareequivalentto0or1input.whenyouconvert5tobinary,it's0101.Thebinaryof1is0001.Sowhenweonlyconnectthefirstswitch,thedisplaydisplays1.Whenweconnectthefirstandthethirdswitch,thedisplaydisplays5.123.3circuitdiagram3.4ResultdemonstrationWhenthewatertemperaturereaches1°C,display113●whenthetemperatureofthereaches5°C,display54.ConclusionThroughthisexperiment,letmelearnalotaboutthedetectionofcomponents,aswellassomebasiccircuitdesign.Thisprocessletmehaveaverydeepunderstanding,Ithinktodowellintheexperimentweneedtounderstandtheprinciplesofthecircuit,whenthecircuitfailure,wemustusethecirc