Teac-FD-55-AV-Service-Manual电路原理图.pdf
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1、TEACFD-55AV/GV MINI FLEXIBLE DISK DRIVE MAINTENANCEMANUAL REV.A RadioFans.CN 收音机爱 好者资料库 TEACFD-5SAVGV MINI=XI3LEDISKDRlJE H.INTI:N;_GP.Jl.NU;lL -i- RadioFans.CN 收音机爱 好者资料库 TABLEOFCONTENTS TitlePage SECTION3THEORYOFOPERATION300 3-1CONSTRUCTIONANDFUNCTION301 3-1-1GeneralBlockDiagram301 3-1-2Mechanical
2、Section_302 3-2CIRCUITDESCRIPTIONS307 3-2-1ReadWriteCircuit307 3-2-1-1Modeselector(forreadwritecircuit)309 3- 2-1- 2Rea d cireuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311 3-2-1-3Writecircuit.315 3-2-1-4Lowvoltagesensor317 3-2-1-5Functionandopera
3、tingwaveformofreadwriteLSIterminals318 3-2-2ControlCircuit326 3-2-2-1Strapcircuit328 3-2-2-2LEDandheadloadcontrolcircuit.329 3-2-2-3Write/erasecontrolcircuit333 3-2-2-4Mctorongate.335 3-2-2-5Readydetector336 3-2-2-6Steppingmotorcontrolcircuit339 3-2-2-7Trackcounter343 3-2-2-8Otherterminalsandfunctio
4、nofcontrolLSI344 3-2-2-9Interfacedriver346 3-2-3ServoCircuit347 3-3FUNCTION OFTESTPOINTSANDVARIABLERESISTORS38 3-3-1FunctionofTestPoints349 3-3-2FunctionofVariableResistors354 -ii- TitlePage SECTION 4MAINTENANCE.4000 4-1GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5、 . . . . . . .4001 4-1-1PeriodicMaintenance4001 4-12CheckandAdjustment.4002 4-1-3MaintenanceJigsandTools4003 4-2PRECAUTIONS. . . . . .4007 4-2-1TorqueAppliedtoScrewsandLockingPaint4007 4-2-2HandlingofConnectors4008 4-2-3HeadCableTreatment4013 4-2-4InitialSettingofSKA-GandSKA4015 4-2-4-1Cableconnecti
6、onandsettingofpowersupplyvoltage4015 4-2-4-2Settingofthemaximumtracknumber4018 4-2-4-3Settingofsteprateandsettlingtime.4018 4-2-4-4Leveldiskcalibration4021 4-2-4-5Alignmentdiskcalibration4023 4-2-4-6Humiditysetting4026 4-2-4- 7Setting0fSKAgain4026 4-2-4-8SettingofFDDstrapsandSKAspecialkey4027 4-2-5O
7、thers4029 4-3PREVENTIVEMAINTENANCE4032 4-3-1CleaningofMagneticHeadbyCleaningDisk4032 4-3-2DirectCleaningSinglesided4034 4-4CHECKANDADJUSTMENT4036 4-4-1AdjustmentofSetArmPosition4036 4-4-2CheckandAdjustmentofHolderPosition.4038 4-4-3CheckandAdjustmentofArmLifter4041 4-4-3-1)()ublesided4041 4-4-3-2Sin
8、glesided4051 4-4-4CheckofCSSAssY-.f054 4-4-5CheckofFileProtectSensor.4058 4-4-6CheckofDiskRotationSpeed4061 4-4-7CheckofEraseGateDelay4063 4-4-8CheckofHeadTouch4066 -iii- 4-4-9 Title CheckandAdjustmentofAsymmetry Page 4072 CheckandAdjustmentofTrackAlignment.4084 CheckandAdjustmentofTrack00Sensor.409
9、3 CheckandAdjustmentofTrack00Stopper.4100 CheckandAdjustmentofIndexBurstTiming.4105 4077 4080CheckofResolution CheckofReadLevel4-4-10 4-4-11 4-4-12 4-4-13 4-4-14 4-4-15 4-5MAINTENANCEPARTSREPLACEMENT4110 4-5-1ReplacementofHeadCarriageAssy.4110 4-5-1-1 4-5-1-2 Replacementofv-typecarriage Replacemento
10、fL-typecarriage 4110 4117 4-5-2ReplacementofSteppingMQtorAssy4121 4-5-3ReplacementofDDmotorAssy0 ,., CD :xlJJz:x 0 - ,. c: :10 , -l .0 ,.,.,0 V) - ,., Cj)(j)CDz: :xz:x:x -l - .:lC :10I0 0-0 ,. -0.0000 .:;:;:;?1r0lLolJL.:.F0-. rwr10lnh8 76,h. r92J,:hC25 TPe ;JIDIFO RiOO_CTIVErn-.C.I-.J1 2TC24 -In-=-_
11、r-_-:.RW.:.1.:.0-fIool.ff3f-+HEAOf-tl.PRE.0JFFERENHATORI-CJ-:TP7 _ 8L.:.:.SWITCHf-tl.AMPEAK/.:uo.J.:.:._-S-y-6-4Ib- r-v-R01-IT!f-+MATRIXV=:E.ETECTORA t,.10R11r-:-=-LOWVOLTAGESENSOR -.-.J-=-.:;.-4-.1r-.:.:.-.lIDVGGLVsolLVS1tiil.-. -4oYEVCCIITIMEtacP WTr-:-=-rDOMAINlMECONSTAllT -.r-L1l.IWRJTElI-JrIFI
12、LTERC21. C22.RAg liT18-DRIVER l.!. ,.9COM1r;-;:- SIol-E1-:r-t-+-.-H-:=.!.-I.19ItCOMI.IONItEJ HEADHJ,.EVCCDRI VeilrJI .Ir lr-+-=COMOr-I1 Crl3.;R12illt,WRllE.Ir- L_+-NvAr-if-+-_E:.!:D1-1mHERASEleuRRENT/IiRJTECONlR0L :114-=-:;-+-. DRJVEIlSOURCElOG IC t,tttIfR0DRJVERr-r-,.-I-.-.-.-, 4UD6;D Rl1OVEGNDI.,-
13、:nc:,.,l.J),-,:llCI .-J.IVI.-+-t- -.l0nntnI0II:;)C)I-LJ oVIVIIII 0 I- -.tIWRI1ECURRENTIOUTPUT 1SY),lMETRYADJUSTOR5WJTCHTPc IIDRIVER ftRe.R9.Q1 ,I- w a CD 3-2-1-1.Modeselector Modeselectorisconstructedwiththeswitchfilterandwritecurrent switch,whichareusedonlyfor96tpimodels. Table301showstheswitchingc
14、onditionofthereadwritecircuitby thetrackswitchsignal(SFsignalintheschematicdiagram)fromthe controlcircuit. (1)Switchfilter SwitchfilterisusedonlyinGmodelandinoptionalFmodelfor eliminatingtheinfluenceofsaddlewaveform(refertoFig.304)atthe outertracks.WhentheSFsignalisHIGHlevel,theoutputoftheNPN transi
15、stors,Q7andQ8(includesresistorsintrnally)becomesLOW level.Thentheswitchfiltercapacitors,C30andC3lareactivatedto increasethecapacityofthelowpassfiltercapacitor,C29.Thisstate istheOn-stateoftheswitchfilter,andthecut-offfrequencyofthe lowpassfilterissettolow. (2)Writecurrentswitch Writecurrentswitchisu
16、sedonlyinE,F,andGmodelsandusedfor makingthewritecurrentinoutertracks(track00totrack43)higher thanininnertracks(track44totrack79)toimprovetheover-write (write2FafterIFwriteandmeasuretheresidualfrequencycomponents ofIF)andsholdercharacteristics. Writecurrentissuppliedtothewritedriverbywritecurrentsour
17、ce inthereadwriteLSI,US.Thesuppliedvaluefromthiscurrentsource canbecalculatedfromthefollowingexpressioncombiningtheexternal resistorsR9,R8,andQl(ONatoutertracks). 13.212.7121 Outertracks:Iw=+-O.-No. -309- 13.2 Innertracks:Iw=-0.12-No.2 R9 (Reference) Erasecurrentiscalculatedfromthefollowingexpressio
18、n.Write currentisnotswitcheddependingonthetrckposition. Ie=10.8-No.3 Rll(orR12) Modelsandtrackposition SwitchingitemA,B(48tpi)E,F(96tpi).G(96tpi,highdensity) alltracksTr.00V43Tr.44V79Tr.0QV43Tr.44.,79 SFsignal . . HHLHL Switchfilter I NocircuitONOFFONOFF Writecurrentsw.ConstantNo.1No.2No.1No.2 (Curr
19、entexp.)No.2 ErasedriverConstant + (Currentexp.)No.3 (Table301)Switdhingfunctionofmodeselectorforreadwritecircuit -310- 3-2-1-2.Readcircuit Thereadcircuitconsistsofheadmatrixswitch,pre-amplifier, lowpassfilter,differentiationamplifier,peakdetector,timedomain filter,andoutputdriver.Maincircuitsareenc
20、losedintheread writeLSI,US. Theminutevoltageinducedinreadoperationbytheread/writeheadis inputtopre-amplifierviamatrixswitchforselectingside0/1heads. Thepre-amplifierhasthreegainsettingterminals,GSa,GSIandGSC. InAFmodels,GSO-GSCisshortedtoobtainthegainof100times, whileGSl-GSCisshortedinGmodeltoobtain
21、thegainof200times. Thepre-amp.outputissuppliedtothedifferentiationamplifiervia thelowpassfilterandtheswitchfiltertoliminateundesirablehigh frequencynoises.Thedifferentiationamplifierphase-shiftsthepeak positionofthereproducedwaveformtozerocrosspoint,andatthe sametime,furtheramplifiesthesignalwiththe
22、mostappropriate equalization.Thepeakdetectorconstructedwithacomparatorconverts thedifferentiatedoutputafterpassingthroughthecouplingcapacitors, C24andC25intoaquarewave. Thetimedomainfiltereliminatesavirtualpulsecausedbythesaddle inthelowfrequencyarea(IFarea,62.5KHzforAFmodels,125KHz forGmodel)atoute
23、rtracks.Thetimedomainfilterisconstructed withtwoedgedetectors,delaysingleshot,readdatalatch,anddata singleshot.ThenthesignalisoutputfromtheFDDthroughtheRD driverandtheoutputdriver. IntheRDdriver(3-stateoutput)ofthereadwriteLSI,US,there aresomegates.TotheTDCRterminalforpulsewidthsettingofdelay single
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