文献翻译——数字油耗

第1页外文文献资料DigitalfuelconsumptionAutomobilevehiclesrunningongasolinehaveagasolinestoragetank.Thestoragetankhasalevelsensingdevicegenerallycomprisingavariableresistorwhichincreasesinresistanceastheliquidlevelinthetankdecreases.Thisproducesavoltageincreaseacrossthevariableresistorastheleveloftheliquidinthestoragetankdecreases.Today,mostvehiclesutilizeamagneticmechanicaltypegauge.Thegaugecontainsamagneticcoilwhichmovesthepointerrelativetothevoltageacrossthevariableresistorinthefueltank.Itisdesirabletohaveamoreaccuratelevelsensingdevicewhichgivesthedriverofthevehicletheexactamountoffuelleftinthestoragetanksothathemayestimatehisremainingdrivingdistance.Inaddition,thedevicegivesmorereadilyusableinformationincalculatingfuelconsumptionrateandisparticularlyusefulinrallytypevehicles.Itisparticularlydesirabletoutilizeadevicewhichmaybeadaptedtouseinallvehicleswiththepresentgasolinetanksendertominimizereplacementofthesendingunit.Ihavedevisedadigitalelectronicfuelgaugewhichgivestheexactquantityofgasolineremaininginthefueltankwithouthavingtointerpolateagauge.Thedeviceisadaptabletoallsizefuelstoragetanksandattachestothetanksenderunitpresentlyemployedonnearlyallvehicles.Thedevicecomprisesapre-amplifyingcircuitwhichconvertsthevariableDCresistanceofthetanktransmitterelementintopreciseDCvoltagelevelswhichmaybeconvertedintodecimalcodes.ThedisplayunitcontainsthreeLEDonedigitreadoutsrepresentingtenths,unitsandtensofgallonsoffuelremaininginthetank.Thetanksenderunitisavariableresistorgenerallycomprisingamoveablearmattachedtoafloatwhichrestsonthesurfaceoffuelsuchthatasthefuellevelchangestheresistanceoftheelement第2页changesgenerallyfromalowresistancewhenthetankisfulltoahighresistancewhenthetankisempty.Thedeviceutilizesananalogtodigital(A-D)convertercircuitwhichconvertsDCvoltagelevelstoabinarycodeddecimaldigit(BCD)code.TheDCvoltagelevelsaregeneratedbyapreamplifiercircuitcomprisingavoltagedividerbetweenthetanksenderunitandavariableresistance.Thevariableresistanceisutilizedtocalibratetheunitfortheparticularstoragetankutilizedsuchthat,ifthetankholds30gallonsthedeviceiscalibratedto30.0gallons.Thevoltagelevel,whichisgenerallythereverseofthetypeofsignalneededbytheA-Dconverterisinvertedinpolaritybythesignalprocessingunitofthepreamplifier.Theselevelsaretransmittedtotheanaloginputofananalogtodigitalconvertersubsystem.ThevoltageoftheanaloginputdeterminestheoutputoftheA-Dconverter;forexample,aninputof1.00voltresultsinanoutputof000andaninputof2.00voltsresultsinanoutputof999.Thesubsystemgeneratessignalstodrivetheanalogtodigitalconverterwhichconvertsthesignalstoafour-bitbinarycodeddecimal(BCD)codewhichisfedintoadecimaldigitto7-segmentLEDdecoderunit.ThedecoderisconnectedtothethreeLEDunitswhichproduceonedigitoutputpergroupofBCDsignals.Thedecoderhas7outputlinesconnectedinparalleltoeachLEDdisplayunit.TheA-Dconverterturnseachdisplayuniton,sequentially,aseachgroupofBCDsignalsistransmittedtotheLEDunits.Avoltagecomparatorcomparestheoutputofthesignalprocessorandifsaidoutputfallsbelowapredeterminedlevelthecircuitinitiatesawarningsignalbyinterruptingthedecoderoutput.Interruptioniscausedbygroundingthedecodercircuitonaperiodicbasis,usuallybyanoscillatortimingcircuit.Astabilizingcircuitisutilizedtopreventincidentalchangesinthedisplayoffuelquantityduetothedrivingofthevehiclewhicharenormallydampenedoutbymagneticmechanicaltypegaugeswhichareslowertoreact.ThecircuitallowsanoutputfromtheA-Dconverteronceevery15seconds.Avoltageregulatorisemployedtoprovideaconstantpositive5voltsfor第3页drivingthecircuit.Theprimaryobjectoftheinventionistoproduceadigitalreadoutfuelgaugewhichisadaptabletoallmakesandtypesofvehiclestoreadtheleveloffuelremaininginthefueltank.Anotherobjectoftheinventionistoproduceadevicewhichaccuratelydisplaysthelevelofliquidleftinastoragetank.Afurtherobjectoftheinventionistoproduceadigitalreadoutdevicewhichalsowarnsthedriverofalowfuellevel.Afurtherobjectoftheinventionistoproduceareadoutdevicewhichiscapableofbeinginsertedinthedashwherethepresentmechanicaltypegaugeislocatedonthevehiclethusrequiringminimalmodificationsofthevehiclespanel.Astillfurtherobjectoftheinventionistoprovideafuellevelreadoutdevicewhichisaccurateandhighlysensitivetochangeswhichmaybeemployedtogiveaccuratefuelconsumptionratesandcomputetheremainingtraveldistanceofthevehicle.Otherandfurtherobjectsoftheinventionwillbecomeapparentuponareadingofthedetailedspecificationhereinafterfollowingandbyreferencetothedrawingsannexedhereto.DESCRIPTIONOFTHEDRAWINGSThedrawingsofthepreferredembodimentoftheinventionareannexedheretosothattheinventionmaybemorefullyunderstood,inwhich:Numeralreferencesareemployedtodesignatevariouselementsandlikenumeralsareusedtodesignatelikeelementsthroughoutthevariousfiguresofthedrawings.DESCRIPTIONOFAPREFERREDEMBODIMENTGenerallyreferringtoFIGS.1and2ofthedrawings,thedevicecomprisesadigitalelectronicfuelgaugewhichdisplaysthequantityorvolumeofliquidremaininginthestoragetankT1bya3-digitreadoutdisplay17comprisingthreeLED(LightEmittingDiode)7segmentdisplaysrepresentingtenths,unitsandtensofgallons.ItshouldbereadilyappreciatedthatthedevicemaybeexpandedtoanynumberofdisplayLEDcircuitsnecessarytoreadthecapacityofthetank.Thedescribedformoftheinventioniscapable第4页ofreading99.9gallonswhichissuitableformostfueltanksusedoncommercialorpersonalvehicles.Thefuelgaugeisconnectedtovariableresistanceliquidleveldetectionmeanssuchastheexistingsenderelement6(FIG.3)whichcomprisesavariableresistorR16havingaslidingbrushBconnectedtoafloatFwhichrestsonthesurfaceofthefuelsuchthatasthefuellevelchangestheresistancevalueofR16alsochanges.ThedevicemovesfromthepositionshownindashedoutlineFtothepositionshowninfulloutlineF.ThetanksenderunitisenclosedintankT1andgenerallyhasapproximately70ohmsofresistancewhenthefloatFisatpositionFand10ohmsofresistancewhenthefloatFisatpositionF.VariableresistorR16generallyhasoneendconnectedtothepositivevoltagesourcebyline33andtheotherendisgroundedtothechassisofthevehicle.Afuelline7ispositionedintankT1andconnectedtofilter9.VariableresistorR16formsaportionofavoltagedividernetworksuchthatthevariationsofDCvoltagelevelareconvertedintoaBCD(binarycodeddecimal)digitcodebyA-D(analogtodigital)converterZ4.TheBCDdigitcodeisthendecodedbydecimaldigitto7-segmentLEDdecoderZ5andilluminatedononeofthedisplayindicators18,20or22ofdisplay17.ThedigitalfuelgaugehasalevelcomparatorcircuitZ1BwhichsensestheDCvoltagelevelappliedtotheA-DconverterZ4suchthatwhenthevoltagelevelreachesapredeterminedthresholdlevelwhichcorrespondstoapredetermineddigitaloutput,forexample,3.0gallons,thelevelcomparatorZ1Bgeneratesanoutputsignal.TheoutputfromanoscillatorcircuitisselectivelypassedtodecodercircuitZ5throughNANDcircuitsZ2AandZ2BtocausetheperiodicinterruptionofcircuitZ5,causingaflashingoftheoutputoftheindicators18,20and22aswillbemorefullyexplainedhereinafter.Aswillbecomeapparentfromthefollowingdescription,thedeviceutilizessolidstateelectronics.Thedeviceisgenerallyconnectedtoa12voltpowersupplysuchasbattery8whichisgenerallyfoundinmostmodernvehicles.Line10connectsthe12voltsfrombattery8throughresistorR17tovoltageregulator27.A第5页stabilizingcapacitorC3isconnectedbetweenline10andgroundtofilteroutundesirablenoise.VoltageregulatorZ7isacommon3pintyperegulatorsuchastypeF78L05manufacturedbyFairchildSemiconductorortheequivalent.ThevoltageregulatorZ7producesaconstantpositive5voltswhichisconnectedbyline12tointegratedcircuitsZ1,Z3,Z4,Z5,andZ6.The5voltsourceisconnectedtoavoltagedividernetworkwhichdividesbetweenlegs30and31.Leg30ofthevoltagedividernetworkisconnectedtoresistorR1whichisfurtherdividedintoavoltagedividerwithsides33and34.Side33isconnectedtovariableresistorR16ofthetankT1.VariableresistorR3isconnectedinserieswithresistorR2.ResistorR3isapotentiometerwhichisadjustabletocompensateforthesizeoftankT1,aswillbemorefullyexplainedhereinafter.Side34isconnectedtoapreamplifiermeansgenerallycomprisingasignalprocessorZ1AwhichcomprisesaportionofintegratedcircuitZ1suchastypeNE532VmanufacturedbySigneticsCorporation.SignalprocessorZ1AinvertsthepolarityoftheDCvoltagesignals.Theoutput(pin1)ofsignalprocessorZ1Aisconnectedtotheanaloginput(pin1)ofanalogofdigitalconvertersubsystemZ3.Inaddition,theoutputpin1fromZ1AisconnectedtoresistorR5totheinput(pin6)ofvoltagecomparatorZ1B,thesecondportionoftheintegratedcircuitZ1.TheanalogtodigitalconvertorsubsystemZ3containsthegeneralcontrolsoftheA-D(analogtodigital)converterZ4andisgenerallyofatypeMC1405LandA-DconverterZ4isatypeMC14435VPorequivalent,botharemanufacturedbyMotorola.Aninputof1.00voltstoanaloginput(pin1)ofsubsystemZ3999;causesabinarycodedoutputfromA-DconverterZ4of000.Aninputof2.00voltstoanaloginputpin1ofsubsystemZ3willcauseabinarycodedoutputfromA-DconverterZ4of999.Voltagesbetweentheseparameterswillcauseadigitaloutputbetween000and999;forexample,aninputof1.300voltswillresultinacodedoutputof300.Lines16and15connectthesubsystemZ3withtheA-DconverterZ4.TheA-DconvertorisaprocessingorconvertormeanswhichchangestheDCvoltagelevelsfromside34ofthevoltagedividerintoaBCD(binarycodeddecimal)digitcode.The4bitBCDcodeistransmittedthroughoutputpins11-14to第6页decodermeanssuchasthedecimaldigitto7-segmentLEDdecoderdrivercircuitZ5.DecoderZ5isofatypenumberSN7447NmanufacturedbyTexasInstruments,Inc.ofDallas,Tex.ThedecodermeansgenerallycomprisesfourinputstoreceivetheBCDcodeandsevenoutputswhichareconnectabletoastandard7-segmentdisplayLEDunitsuchasindicators18,20,and22.Inthepreferredembodiment,theA-DconvertorZ4transmitsbywayofoutputlines11-14threedifferentgroups,eachgroupcomprisingasingledigit.Eachofthesegroupspickupthetenpossiblepatternsofhighandlowvoltagelevelstoformthedecimaldigitonindicators18,20and22.TheA-DconvertorZ4containsadditionalcircuitrywhichrapidlyscansfromonegrouptoanother,sequentiallymakingeachgroupavailableatoutputlines11-14foranintervalofapproximately50microseconds.EachgroupofcodeisreceivedbythedecoderZ5andtransmittedthroughoutputpins9,10,11,12,13,14and15tothe7-segmentindicators18,20,and22.Thedisplayunits18,20and22comprisebasicLEDdisplayunitssuchastypeHP5082-7750forunits18and20andHP5082-7730fordisplayunit22bothmanufacturedbyHewlett-Packard.A-DconverterZ4has3outputpins1,15and2whichsequentiallyhavealowoutput.Pins1,15and2areconnectedthroughdiodesD1,D2,andD3andresistorsR11,R12andR13tothebasesoftransistorsQ1,Q2andQ3,respectively.ThecommonemittersintransistorsQ1,Q2,Q3areconnectedtotheline10.ThecollectorofeachtransistorQ1-Q3isconnected,respectively,topin3ofindicatordisplayunits18,20and22.Sincethe4bitBCDcodeistransmittedinthreegroups,eachgroupissequentiallytransmittedovertheoutputlines9-15ofdecoderZ5toeachoftheindicatorunits18,20and22.TheA-Dconvertorhasanormallyhighoutputonpins1,15and2.Whentheoutputissequentiallymadelowoneachpin,thisenableseachtransistorQ1,Q2,andQ3,respectively;thus,connecting12voltstoenabletherespectiveindicatorunits18,20or22.Theresultisthatonlyoneindicatorunit18,20or22willlightupatatimeforthedatagrouppresentontheA-Dconvertoroutputlines11-14.Theendresultisthatthethreedigitslightuponeatatime,sequentially,inarepeatedpattern第7页whichissofasttheeyeperceivesalldigitstobecontinuous.Forexample,eachofthethreedigitshaveacyclewhichrepeatsapproximately6600timespersecond.Theintegratedcircuit21containsavoltagecomparatorcircuitZ1B,ashereinbeforedescribed.Thesecondleg31oftheprimaryvoltagenetworkcomprisesaseriesofresistorsR6,R7andR8.Areferencevoltageistappedfromleg31betweentheresistorsR6andR8andisconnectedtoinputpin5ofthevoltagecomparatorcircuitZ1Bbyline40.ThisprovidesareferencevoltagetocomparewiththeoutputofsignalprocessorZ1A.WhentheoutputofthesignalprocessorZ1Adropsbelowapredeterminedlevel,ascomparedtothereferencevoltage,awarningsignalisdeveloped.Whentheinputtopin6ofthevoltagecomparatorZ1Bishigherthantheinputatpin5,theoutputofpin7isnormallylow.Whentheinputtopin6dropsbelowpin5,theoutputofpin7ishigh.ThisenablestwoparallelNANDgatesZ2AandZ2B.TheNANDgatesZ2AandZ2BareconnectedtoalowfrequencyoscillatorformedbycircuitsZ2CandZ2D.Thelowfrequencyoscillatorproducesapulseorcycleapproximatelyevery1.5secondstoNANDgatesZ2AandZ2Bthusdrawingpin4ofdecoderZ5down.AnadditionaltransistorQ4isplacedonline36toaidingroundingpin4tointerruptdecoderZ5.NANDgatesZ2AandZ2BacttoperiodicallyinterruptthedecoderZ5outputpins9-15ofdecodercircuitZ5bygroundingsame.Thiscausesaflashingoutputontheindicatordisplays18,20and22whichservesasalowlevelwarningsystem.Thethresholdlevelofthevoltageinputtopin6ofthevoltagecomparatorZ1Bisadjustablebyplacingapotentiometer(notshown)oninputpin5tocircuitZ1B.ThecircuitsZ2A,Z2B,Z2CandZ2DmaybeproducedinintegratedformandmaybeofatypenumbersuchasCD4011AEmanufacturedbyRCA.Inaddition,theoutputoflowfrequencyoscillatorsZ2CandZ2DisconnectedtodecadecounterZ6.DecadecounterZ6hasoneoutputforeach10inputsfromthelowfrequencyoscillator.Thedecadecounteroutputhasoneoutputapproximatelyevery15seconds.TheoutputsignalfromcounterZ6isconnectedthroughadifferentiatedcircuitformedbycapacitorC2andresistorR10.ResistorR10isconnectedtopin6oftheA-DconvertorZ4.TheoutputofdecadecounterZ6isnormallylow;however,witheverycycle第8页(15seconds)theoutputpeaksupward.ThisallowsachangeintheoutputofanalogdigitalconvertersZ4.ProblemsdevelopwhenthemovingstoragetankT1isinavehiclewhichismovingoverroughsurfaceandthereforehastemporarychangesinthelevelduetosloshingoftheliquidinthetank.Thesystemissofastthatitwouldnormallyreflectthesechangesandgiveaconstantchangeintheliquidlevel.ThepurposeofthedecadecounterZ6istolimittheoutputonthe4-bitBCDcodeconnectedfromoutputs11-14toalongertimeperiod,suchasevery15seconds.AlthoughinformationfromsubsystemZ3isconstantlytransmittedtoA-DconverterZ4,theoutputoftheA-DconvertersislimitedtoonechangeeverycycleofdecadecounterZ6.Itshouldbereadilyapparentthatbychangingthelowfrequencyoscillatorthetimeofthelengthofthecyclewillbechanged.ThedecadecounterZ6isofatypenumberCD4017CNmanufacturedbyRCA.FromtheforegoingitshouldbereadilyapparentthatthecircuitprovidesavoltagelevelsensingdevicewhichconvertstheDCvoltagelevelstotheproperdigitalformfordecimaldigitdisplayonthe7-segmentLEDcircuitsuchasindicators18,20and22.Inpractice,allvehiclesofdifferentmanufacturehavedifferentsizefuelstoragetanks.Thesetanksrangeanywherefrom8to30gallonsonanormalpassengercarandhavelargercapacitiesoncommercialvehicleswhichcontainlargertanks.VariableresistorR3isprovidedinthecircuitforinitialadjustmentoftheoutputdisplaytoafulltank.AdjustmentisaccomplishedbyfillingthetankT1withfuel.ThenvariableresistorR3isadjusted,byturningsame,tocauseanindicateddisplayonindicators18,20,and22toequalthequantitygivenbymanufacturersspecifications.Forinstance,ifthetankT1holds30gallons,variableresistorR3wouldbeadjusteduntiltheindicators18,20,and22read30Indicatorunit22ispreferablyasmallerunitthanunits18and20toindicatetenthsofagallonwithoutthenecessityofhavingadecimalpoint.AsvariableresistorR16moveswiththedecreasingfuellevel,theresistancechangesfromapproximately10ohms,atfull,to70ohms,atempty.ThiscausesanincreaseinvoltageacrossresistorR16fromapproximately0.2voltswhenthetankisfullto1.5voltwhenthetankisempty.Thiscausesa第9页decreaseinvoltageacrossleg34ofthevoltagedivider,andthereforeadecreaseintheanaloginputpin1ofsubsystemZ3.Astheanaloginputvoltagedecreasesforinstance,fora30gallontank,from1.300to1voltthedigitaldisplaywilldecreasefromthe300to000.Therespectivevalueofeachcomponenti