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Documentation VFD clock “8 – a clock”

Thisdocumentationisprotectedbyourcopyright.Itmustnotbeusedforcommercialpurposes.

CongratulationsonyourpurchaseofyourVFDclock.Toguaranteesuccessintheconstructionoftheclock,itisessentialtohavegoodtoolsonhand,suchasaspecialsidecutterforelectronicsboards,asmallflatpliers,tweezers,scissors,screwdriversandamultimeter.Technicalspecifications:Operatingvoltage9-12voltsACorDC-50Hzor60HzTubesused:IV6-8pieces12/24hrformatUSandEuropeandateformatCurrentconsumption:120mAat12VBoarddimensions:approx109x50mmOptionalconnectiontoaDCF77orGPSreceiverDCF77orGPSdisplaythedateinthe50thsecondfor5seconds1.SafetyandLegalNotesDANGER: This circuit design includes a switching-mode voltage-converter which generates 40 V DC. Therefore onlycompetent and qualified personnel experienced in electronics assembly should attempt assembly. Safe assembly andoperationofthiskitiscompletelythereader’sresponsibility.

IMPORTANT:Pleasefollowtheassemblystepswithextremecare.Pleaseoperatetheclockonlyinanenclosedhousing,whichpreventscontactwiththedangerousvoltagespresentonbothprintedcircuitboards(PCB).

DISCLAIMER: The information in this document is provided strictly 'as is'. It is hereby stated that this kit is to beassembledonly by experiencedelectronics engineers.No troubleshooting information is provided. Readers shouldnotattempttobuildthiskitand/ordesignunlesstheyarecompetentatelectronicsassemblyandunderstandthedangersofmains voltages. Further, we take no responsibility for any possible personal or property damage. No responsibility isacceptedforanydamage,injury(howeverserious)ordeath.Innoeventshallwebeheldliabletoyouoranythirdpartiesforanyspecial,punitive,incidental,indirect,consequential,oranyotherdamagesresultingfromtheassemblyoruseofthiskitand/ordesign.Theassembledunitshouldbeproperlyencasedtopreventcontactwithhighvoltages.

AllapplicableUL,CCE,VDEandlocalregulationsmustbeconsidered.

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Partlist

Part Type Designator Footprint Parts 22NF C1, C8, C15 Capacitor / 223 3 10NF C14 Capacitor / 103 1 100NF C2, C7, C10 - C13 Capacitor / 104 6 22p C16, C17 Capacitor / 220 2 470uF 16V C3, C4, C6, C9 Capacitor 4 68uF 63V C5 Capacitor 1 BRIDGEDIL4 D1 Rectifier 1 BZX79C5V6 D2 Zener Diode 1 1N4002 D4 Diode 1 1N5818 D3, D6 Schottky Diode 2 BAT41 D5, D7 Schottky Diode 1 LM2671N-5.0 IC1 Switching regulator 1 ATMEGA88_DIP28 IC2 ATMEGA88_DIP28 1 MAX6921AWI IC3 VFD Driver already mounted 1 CON3 J1 DC-connector 1 MINIDIN J2 Mini DIN socket 1 100UH 500mA L1 - L3 Inductor 3 LED3mm LED1 - LED8 LED 3mm 8 ZVN4210A Q1, Q3 TO-92FET 2 VP3203N3-G Q2 TO-92FET 1 33k R1 Resistor 1/8 Watt 1 470K R3, R10 Resistor 1/8 Watt 2 1k R6, R12, R13 Resistor 1/8 Watt 3 10K R2, R9, R11, R14 Resistor 1/8 Watt 4 3,3 Ohm R4 Resistor 1/8 Watt 1 2k2 RL1 - RL8 Resistor 1/8 Watt 8 LDR R15 10k LDR resistor 1 SW-ANGLE-THM S1 - S3 Push button 3 VFD V1 - V8 VFD tube 8 20MHz X1 Xtal 20 MHZ 1 IDC6 NM J3 not mounted 0 Not mounted R5, R7 Resistor not mounted 0 Total number of parts 74

IDC6,R5andR7arenotmounted! IC2sitsinasocket. Althoughthetubesarematchedbydate,itcanhappenthatthedonothavethesamebrightness.

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2.SolderingtheelectroniccomponentsontheboardTheVFDdrivermoduleisalreadysolderedtotheboardasitisSMD.Solderallcapacitors,asseeninthephoto.Thesecapacitorshavenopolarity.

Ifyouusetheclearcase,soldertheLDRresistorR15at90degreesflushwiththeboardedge.SeeFigure.

Ifyouusetheblackcase,soldertheLDRresistorsothatitlatersticksoutabout2-3mmofthehousingasshowninthepicture.

.

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Thisishowtheresistorshouldbeplaced.Checkwiththebackofthecaseifitfitsthroughthehole.

Nextmounttheresistors.Theyareallsolderedstandingup.

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Nowsolderthediodes,thevoltageregulator,IC1andthetransistor.ThenextphotoshowsD1andIC1.Makesuretosolderthemasshowninthephoto.

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WhensolderingthediodesmakesureALLdiodesaremountedwithring-markingpointingUPaspictured.

Inthenextstepofconstruction,theremainingpartsaresolderedin. Whensolderingthecapacitors,makesurethattheyaresolderedwiththecorrectpolarity.Thelonglegoftheelectrolytic capacitorisPLUS. Whensolderingthecrystalensurethatdoesnottouchtheboard.Leaveagapofabout1mmtotheboard. ThecoilsL1-L3havenopolarity,butmakesuretosolderthemparalleltotheboard. Whensolderingthepowerjackandthepushbuttons,makesurethatitisinrightangleandisparlalleltothe backofthepcb. ThesameistruefortheminiPS/2socketfortheoptionalconnectionofaDCForGPSreceiver.Thus,solderingonthe componentsideiscompleted. Don’tsolderJ3.Itisonlyusedforsoftwareupdatebyus.

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3MeasuringthecorrectvoltagesontheboardYouhavenowsolderedALLpartsintotheboard,exceptthetubesandtheLEDs.Nowpoweruptheboardandmeasurethevoltages1V,5V,12Vand40VontestpointsofthepcbtoGND.Checktheyareallwithinthespecifications(seeschematics)beforeanytubesaremounted.The1VisVERYimportant.Ifitisover1.3V,thenfixtheerror.Don’tmountthetubes!The40Vsupplyis70-80Vunloaded,whennotubesaremounted,thisisnormalandok.

PinIDphotoVFDtube

Thisphotohelpsyoutoidentifytheleftandtherightsideofthetube.

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4 TheVFD“IV6”tubes

Tofindouthowtomountthetubepleaselookatthepicturebelowandalwaysfollowtheinformationthere.

Youneednotbendthewiresasshowninthepicture.Thisphotoisonlyforyourinformation.Thereare6wirestotheleft(3,4,5,6,7,and8)andthereare5wirestotheright(2,1,11,10and9).Ifyouhaveashortwireonthetube,youcancutit.Itisnumber“12”onthepicture.Youdon’tneedthatwire.Sometubesdon’thavethatwire,sothereisjustagap.Thetubesarenewoldstock,sotheyareatleast20yearsold.Itmightbeimportanttotestthetubesbeforeyoumountthem.Unsolderingatubeisabitdifficultbutpossible.Againlookatthepicture.Connectwire8and7temporarilyandconnectthemtooneleadyourmultimeter.WewanttomeasureOHM.Nowtesttherestofthewireswiththesecondleadofyourmutlimeterandbesurethereisnowconnection.Afterhavingsuccessfullytestedthetubedisconnectthewires7and8. If thetubeseemstobedefective,get intocontactwithus. We have spare tubes in the shop. We can of course notguaranteethefunctionofthetubes(NOS).Tomakemountingofthetubeeasiercutthewirestodifferentlength.See the picture on the right for more details. Having cut thewireslikethisitismucheasiertomountthetubestothepcb.Nowinsertthewiresintotheholesonthepcb.Remember,onthepcbthereare5holesontherightand6holesontheleft.Pleaseadjustthetubesothatitisinrightanglefromthefrontandfromtheside.

Cuttingthewirestodifferentlength

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Thedistancefromthetubetothepcbshouldbe4-5mm.Solderoneortwowiresfromthetopandthentestagainifthetubesitscorrectly.Nowsoldertherestofthepinsfromthebottomandcutallthewiresfromthebottomofthepcbandcheckforshortagesandrestsofsolder.Youcanusethetopplateofthehousingasastenciltocheckwhetherthetubesarestraight!Checkeverytube!

ThelastpartstosolderaretheLEDs.TheLEDshave2differentwires.ThelongeroneisPLUS,theshorteroneMINUS.ShortenthelegsandrememberthePLUSwire.SoldertheLDEsasshowninthepicture.Thelongwires(PLUS)pointtothebackoftheboardwherethevoltageconnectoris.InserttheLEDsintotheholesothatitreachesoutabout3-4mmontheothersideoftheboardandalmosttouchthetube.AligntheLEDandsolderthemincarefully.

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5 Connecttheclocktopower TheclockcanbeoperatedwithanACoraDCpowersupply.Thesoftwareautomaticallyrecognizestheconnected powersupply,themainsfrequencyandDCF77orGPSoperation.Afterplugginginthepowersupply,theclockshows “12345678”. ThenthesoftwareversionnumberisshownfollowedbythemeasuredfrequencyifanACpowersupplyisconnected.Ifa DCF77receiverisconnected,thedotinthelasttubeflashesafterhavingreceivedacorrectDCFsignal.IfaGPSreceiveris connected,itmaytakeafewminutesuntilGPStimeisreceived.

6 Settingtheclock UsethebuttonsVALUE,SETorEXtosettheclock. 12-24hourformat(timeanddateformat) Thischangeappliestoallmodes.PresstheVALUEbuttonformorethan2seconds.Thehourdisplayshows"12"or"24", dependingonpre-setformat.Italsochangesthedateformat.Inthe12hoursversiondisplaysthedateasfollows: MM:DD:YYYY.In24hourformatitshowsDD:MM:YYYY. SettingtheclockinACorDCoperation: Press the SET button (middle button). The hours’ tubes shine brighter.With the VALUE buttons set the hours. Press theSETbuttonagain.Nowtheminutesshinebrighter.Settheminutestothenextcorrectminuteofyourreferenceclock. PresstheSETbuttonwiththenextminutechange.Theclockstartsrunning. SettingtheclockinGPSmode: Plug theGPSmodule into thePS/2connectorat thebackof theclockandafter that thepowersupply.Theclocknow displays00-00-00,until a correctGPS signalhasbeen received.After that the clockdisplays the time theGPS receiver transmits.InGPSmodethedateisshownatthe50thsecondfor5seconds. You now need to adjust the GPS offset for your time zone. Press the SET button. The minutes shine brighter. With theEXortheVALUEbuttonyoucannowsettheoffsetin30minutessteps.WiththeEXbuttonoffsetwillbededucted by30minutesandwiththeVALUEbutton30minuteswillbeadded.ThenpresstheSETbuttonagain. SettingtheclockintheDCF77mode: PlugtheDCF77moduleinthePS/2socketandafterthatthepowersupplyandwaituntiltheclockisset.Thismaytake severalminutes.Tocheckwhetherthereceiverisproperlyaligned,thedotofthelasttubeblinksin1Hzsteps.Alsointhis mode,thedateisdisplayedinthe50thsecondfor5seconds.InDCF77mode,theclockcannotbesetinanyway.

7 TheCase Removetheprotectivefoilfromallpartsandapplypleaseusethecottonglovesduringassembly. Insertthe5mmspacersfromthetopthroughtheholesofthepcbandscrewthemtothe15mmspacers.

It should look like this.

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Nowputthebackplatetothegroundplateandbecarefulnottobreakanything.

Setthepcbontothegroundplateandcheckwhetherthe3pushbuttongothroughthe3holesatthebackeasily.Fixthepcbtothebottomplateusingthe3mmscrews.Donottightentoomuch!

Itshouldlikethis.

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Nowmountthe2sidesandthefrontandputthetopplatetothecase.Fixthetopplatewiththe3mmscrew.Donottightenthemtoomuch!

Thelaststepistofixthe4transparentrubberfeettothecornersofthecaseonthebottom.Thiswillpreventscratchesandtheclockwillstandtight.

Wewishyoualotoffunwithyournewclock!