华科数字信号处理实验课作业报告.docx

华科数字信号处理实验课作业报告.docx

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华科数字信号处理实验课作业报告

DigitalSignalProcessing

ExperimentReport

Name:

StudentID:

Department:

Data:

2014.12.15

Experimentone

Bridgeperformancetest

I.purpose

Learnmetalfoilstraingaugestraineffectworksandperformance,comparingarm,half-bridge,fullbridgesensitivityandnon-linearityofoutputanddrawtheappropriateconclusions

II.Materials

1）Opensensortestbox

2）StrainSensor

3）Weights

4）Cables

5）Multimeter

III.Methods

1.AccordingtoFigure1,thewiringcolorsofresistanceonthesensorstraingaugesonR1,R2,R3andR4areyellow,white,red,blue.Useavailablemultimetertomeasurethetwoendsofthesamecolordiscrimination,R1=R2=R3=R4=350.

Figure1

2.AccordingtoFigure2andFigure3,accessresistor300

intoR24,R26,R27,thenconnectR1intoR25ontheboard.Ifthewiringiscorrect,powerit.UseamultimetertomeasurethevoltagebetweenIN0andIN1,adjustpotentiometerR28（100Rpotentiometer）,makethevoltagedifferencebetweenIN0andIN1tozero.wecallthisstepthebridgezero.

Figure2

Figure3

3.Theinstrumentationamplifiercircuitoutputterminaltotheinvertinginputofscalingcircuit,measuredwithamultimeterinvertingoutputterminalofthevoltagescalingcircuit.Fromthethreeformerstageopampamplifier,sinceR30hasbeenfixed,theamplificationfactoroftheamplifierisdeterminedbytheR29（1Kpotentiometer）whenR29tendsto0,themaximumamplificationfactor.Thentheamplifieroutputvoltageisaboutsupplyvoltage（potentialdifferencedependsonthepolarityofthepolarityIN0andIN1's）.Todeterminethespecificamplificationfactorandavoidsaturationoftheamplifieroutput,wherewecanadjusttothetopofthefirstR29anti-clockwise,theresistanceofabout1Kohms.Sopreamplifieritsamplificationfactorofabout201.AfterscalingcircuitlevelinvertingitsmagnificationbyR40（100Kpotentiometer）decidedthatinordertodeterminetheproportionoftheinvertingamplifierspecificamplificationfactorandavoidinvertingamplifierproportionofsaturatedoutput,thenwewilladjustR40counterclockwisecuttothetop.Itsresistanceisabout0inEurope,afterthelevelofmagnificationofapproximately1.Sinceweintroducethetwo-stageamplifier,whenadjusting,increasinguncertainty.Consequently,inadjustingthebeginning,wefirstpre-adjustedtothemaximumofthepotentiometer,thepotentiometertoadjustthesubsequentstagetoaminimum,fixedmagnificationlevels.

4.NotethatR24andR26shouldforcestatetheopposite,thattheforcesensorintwoopposite（atension,apressure）asaresistancestraingaugebridgeadjacentedges.Useamultimetertomeasuretheproportionofdirectlyinvertingamplifiercircuitoftheoutputvoltage.AdjustR42（10Kpotentiometer）,theoutputvoltageiszero,whichwecallthezerooutput.

5.Wheatstonebridgeperformancetest.

100gweightisplacedonthearmtray,seechangesintheamountofvoltage.Ifthevoltagechangeamountisverysmall,thenthefirstclockwiseadjustmentpotentiometerR40,post-stageamplifiercircuittochangethegain（magnification）.Ifyoucanchangetheamountofabout200mV.Notethat,whenchangingtheresistanceR40,R42oftheresistancetobeadjustedagain,inordertomeettheoutputoftheinvertingamplifiercircuitiszeroproportionalrequirements.IfyouadjusttheresistanceR40,theoutputvoltagevariationstillcannotmeettherequirements,theR40clockwisetoadjusttothetop,andthenadjustR29,theoutputvoltagetothevoltagechangeClaim.Notethat,whenchangingtheresistanceR29,R42oftheresistancetobeadjustedagain,inordertomeettheoutputoftheinvertingamplifiercircuitiszeroproportionalrequirements.AfteradjustmentR29,R40remainsunchanged,withtheexperimentaldatatofacilitatelatercomparison.

3.Half-bridgeperformancetest

Accordinginstrumentationamplifiercircuitdiagram（Figure1-2）,theboardwillbeR25,R27access350Ωresistor,theredstrainsensor（orwhite）wirestraingaugesconnectedintothecircuitboardR24,thestraingaugeyellow（orblue）lineR26connectedtotheaccesscircuitboard,thenthestrainR25sheetR1,R3andthecircuitboard,R27connectedasadifferentialDCbridge（halfbridge）.Aftercheckingthewiringiscorrect,power.UseamultimetertomeasurethevoltagebetweenIN0andIN1,adjustpotentiometerR28（100Rpotentiometer）,thevoltagedifferencebetweentheIN0andIN1iszero.

TherestfollowastheaboveExperiment.Notethatifyouhavetoadjustthegainoftheexperimentagoodtune,R29,R40mustremainunchanged.

4.Full-bridgeperformancetest

Accordinginstrumentationamplifiercircuitdiagram（Figure1-2）,thestraingagesensorsred,whitecableaccessboardR24,R27,thestraingaugeyellow,bluecableaccessR25board,R26,formafullbridgecircuit.Aftercheckingthewiringiscorrect,power.UseamultimetertomeasurethevoltagebetweenIN0andIN1,adjustpotentiometerR28（100Rpotentiometer）,thevoltagedifferencebetweentheIN0andIN1iszero.

TherestfollowastheaboveExperiment.Notethatifyouhavetoadjustthegainoftheexperimentagoodtune,R29,R40mustremainunchanged.

IV.Data

Weightisplacedonthetray,invertingthereadscalingcircuitoutputvoltage,increasetheweightandsuccessivelyreadthecorrespondingvoltagevalue.WritedowntheresultstofillinTable1to3,turnoffthepower.

Table1

mass（g）

0

100

200

500

Theoutputvoltage（V）

5.914

9.935

15.114

26.427

Table2

mass（g）

0

50

100

150

200

300

400

500

Theoutputvoltage（V）

-7.794

-5.428

2.409

12.065

13.476

30.107

39.867

56.884

Table3

mass（g）

0

50

100

200

500

Theoutputvoltage（V）

20.837

35.549

41.169

66.796

157.023

V.Results&Discussion

1.AccordingtotheTable1to3,drawchanginggraphofvoltageandweight.

2.CalculatesensitivityS=ΔV/ΔM（ratiobetweenoutputvoltagevariationandtheamountofqualitychange）.

Thethreefittingequationsisasfollow:

y=0.041x+6.131

y=0.130x-9.948

y=0.273x+17.868

Therefore,S1=0.041,S2=0.130,S3=0.273

Calculatethefittingerror:

error1=0.0052499,error2=0.01657,error3=0.34409

Theerrorisacceptedsinceissmall.

VI.Conclusion

Calculatetheexperimentalsensitivityandcompareexperimentalresults.

Fromthesensitivitywecanfindthatsensitivityofwheatstonebridgeisthesmallest,andFullBridgehasthebiggestsensitivity.So,theproperityofFullBridgeisthebest.

Experimentteo-PhotoelectricSensors

I.purpose

Understandtheprinciplesandapplicationsofphotosensitiveresistanceandtransmissiontypephotoelectricswitch

II.Materials

Opensensortestbox

Sensorbreadboard

DCComponents

Severalcable

Multimeter

Logger

III.Methods

Photoresistor

1.Connectthelightsourcecircuitaccordingtofigure1.AdjustthepotentiometerandobservethebrightnessoftheLED,andthencutoffthepower.

Figure1:

Lightsourcecircuit

2.BuildthecircuitonthesensortestboxasshowninFigure2.Checkthewiringcarefullytoensureitiscorrect.Thenturnonthepower.

Figure2:

Photoresistormeasurementcircuit

3.AdjustthepotentiometerlightcircuittochangetheLEDbrightness.Measureandrecordtheoutputvoltagevalue.

Photoelectricswitch

1.BuildthecircuitonthesensortestboxasshowninFigure3.Checkthewiringcarefullytoensureitiscorrect.

Figure3:

Photoelectricswitchmeasurementcircuit

2.Turnonthemotorswitchandthemotordrivesthesmallflywheel.Adjustthespeedknobtochangethemotorrotationspeed.

3.Collectandrecordtheoutputsignal.

IV.Data

1.Photoresistor

Figure4:

thewaveformoftheoutputwithdifferentlightness

Figure5:

thewaveformafterfiltering

2.Optoelectronicswitch

Figure6:

waveformofoptoelectronicswitch

Figure7:

waveformofoptoelectronicswitchafterfiltering

V.Results&Discussion

Accordingtotheresultofphotoresistorexperiment,wecanfindthatthestrongerthelightis,thehighertheoutputvoltageis.

Weknowthatfs=5000,andthenumberofholesontheturntableis12.Accordingtotheresultofoptoelectronicswitchexperiment,wecancalculatethemotorspeedis79.36r/min.

VI.Conclusion

Throughthisexperimentweknowthecharacteristicsandapplicationofphotosensitiveresistance.Ourabilityandanalyticalskillsareexercised.It’sapitythatwelostthedataofresistanceintheexperimentofpholtresistor,sothatwedon’tgetthecurveofthephotosensitiveresistance’svoltagechangewithresistance.Thistoldusthatitisimportanttopreservethedatawhichwegetfromtheexperiment.

Experimentthree-K-typethermocoupleCharacteristicsandTemperatureMeasurement

I.purpose

Understandthetemperaturecharacteristicsandapplicationofthermocouple.

II.Materials

1.Breadboard;

2.K-typethermocouple;

3.OperationalamplifierOP07;

4.1.3KΩ,300KΩresistance;

5.33KΩadjustableresistance;

6.Severaljumpers;

7.Thermometer（bringyourown）andheat.

III.Methods

1.Buildthecircuitshowninthefigure2-1,carefullycheckthewiring,connectthethermocouple.

Figure2-1.ThermocoupleCircuit

2.Makethethermocoupleclosetotheheatsource,andadjustthepotentiometerW1,tomaketheamplifieroutputvoltagemeet10mV/℃.Adjusttheheattemperature,repeatedadjustingpotentiometertomeettherequirements.

3.UseMatlabtomeasurethevoltageVoutandsavethedata.

IV.Data

UseMatlabtoprocessthesaveddata,Igettheresultshowninfigure2-3,2-4,2-5.Theirlightintensityareenhancedonebyone.

Figure2-3.NormalAtmosphericTemperatureFigure2-4.Hand