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CentreforInnovationIndianInstituteofTechnologyMadras
Basicsofelectronics
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CentreforInnovationIndianInstituteofTechnologyMadras
Whatiselectronicsandwhatitcando?Electronicshasrevolutionizedtheworld,seearoundandeverythingneedselectronics.
DevelopmentinelectronicsWehavecomealongway
Funfact:TheApollocomputershadlessprocessingpowerthanacellphone!!
Funfact:"Moore'slaw"istheobservationthat,overthehistoryofcomputing
hardware,thenumberoftransistorsinadenseintegratedcircuitdoublesapproximatelyeverytwoyears.
http://en.wikipedia.org/wiki/History_of_computing_hardwarehttp://en.wikipedia.org/wiki/History_of_computing_hardwarehttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Integrated_circuit
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CentreforInnovationIndianInstituteofTechnologyMadras
Digitalcircuits
Inthisdomain,weconsider2voltagelevelsas0and1.Generally,weconsider1as5V
Q:Wellwhatis3.5Vthen????:PA:Itisconsidered1(actuallyanythinggreaterthan2.5Vwillbeconsidered1)
Analogcircuits
Wehavesignalswhicharevaryinginmagnitudebetweentheextremevalues.
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CentreforInnovationIndianInstituteofTechnologyMadras
Letslookatsomeelectronicscomponents:
Breadboard:Breadboardisaplatformforquickprototypingofelectricalcircuitswithoutusingthesolderingiron.
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CentreforInnovationIndianInstituteofTechnologyMadras
Thehorizontalholesoneachsideofthebreadboardareconnectedtogether.Anythingpluggedintotheseholeswillbeconnectedtogether.Thehorizontalholesononesidearenotconnectedtothoseontheother.Thefirstfiveandthelastfiveverticalstripsareelectricallyconnected.Theouterstripisusuallyusedas5VandtheinneronesasGND.Usuallythefirstfiveandthelastfivestripsarejoinedbywire.Someconventionsthatweusuallyfollow.
Singlestrandwiresareusedforconnections. Connectionsmustbetight.
Nowirewithoutinsulationmustbeseenonthebreadboard.
5VconnectionsareinRed. GNDconnectionsareinBlack.
Otherconnectionsareinanyothercolour.
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CentreforInnovationIndianInstituteofTechnologyMadras
7805TICisusedforsteppingdownvoltages.The05indicatesthatitstepsitdownto5V.Seetheimageforthepinoutdiagramgiveninthedatasheetforthe7805TIC.Whenonelooksatitwithbulgeonittowardsthem,theleftpinistheinputoftheinputvoltage,thecentregroundandtherightpinoutputof5V.
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CentreforInnovationIndianInstituteofTechnologyMadras
LogicgatesTheseareveryhelpfulincircuits.Asthenamesuggests,theyhelptobringlogictocircuits.
Inthetruthtable,actually1means5Vand0means0V.Q:Now,whywouldIneedthem??A:
Imagine 2 smoke sensors connected to A and B. A fire alarm is
connected to F and should
goon(HIGH)wheneitherofthe2sensorsareHigh.Sowhatdoyouusehere?AnORgate.Imagine
a situation where your sensors are highly unreliable ie they out of
a sudden give HIGH output. What to do then? Use AND gate to make
the alarm go on(HIGH) only when both are high.
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CentreforInnovationIndianInstituteofTechnologyMadras
TheyareavailableasICsinthe74xxseries.Eg6NOTgatesinthisIC
CrystalOscillatorCrystals are used to repeatedly generate
signals with a constant frequency. The signals are nothing but
alternate Lows and Highs. We need them to get a sense of time in
circuits. For instance a microcontroller needs to know for how much
time to execute something. There, we needCrystals.
CapacitorsYoualreadyknowaboutthem,theystorecharge.Twotypes:
Electrolytic
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CentreforInnovationIndianInstituteofTechnologyMadras
Ceramic
These2typesaredifferentinthewaytheyaremanufacturedandused.Electrolyticcapacitorshaveanorientationie+veandveterminals.PotentiometersVariableresistorsTheyareusedtogetvoltagesdividedusingtheprincipleofresistancebeingproportionaltothewirelength
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CentreforInnovationIndianInstituteofTechnologyMadras
DiodesTheseusuallyplacedtostopreversecurrents.Technically,thereisasmallreversecurrent,butpractically,wejustusethemasreversecircuitprotectionagents.
Thereisasmallvoltagedropacrossdiodes.Wecanusuallymodelthemasabove.
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CentreforInnovationIndianInstituteofTechnologyMadras
LEDEveryoneknowswhatitis.SeethepinconfigurationforanLED.LEDsneed3Vforpoweringup,andmaygetdamagedat5V.Soalwaysusearesistorinseries(1kohmwillbeagoodvaluetostartwith,changeitifyouwanttomodifythebrightness)
7segmentdisplayYouhaveseenthisindigitalsignboards,watchesetc.Itsreallysimpletouse!!Everydisplaylinehasauniquepinwhichcanbepoweredtomakeitturnonandoff.
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CentreforInnovationIndianInstituteofTechnologyMadras
MOSFETsandTransistorsMOSFETsandtransistorsaretheheartofelectronicsaroundus.Practically,theyareemployedinonefundamentalapplication,asaswitch,anelectronicallycontrolledone.Here,Imeanthatasignalcontrolstheactioninsteadofamechanicalswitchaction.MOSFETsandtransistorsaredifferentMOSFETsareusedforheavyloadapplications.Theyarecurrentcontrollediethecurrentgivenatthegatedecideswhethertheswitchconductsorno
Transistorsontheotherhandarecurrentcontrolled.Thecurrententeringthebasedecideswhetheritconductsorno.
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CentreforInnovationIndianInstituteofTechnologyMadras
TimerICTimerICisanICusingwhichwecangenerateticksofvariousfrequencies,byjustmodifyingthecircuit.
Forexample,youcancheckouthowtogenerate1secticksusingitherehttp://electrotech4u.blogspot.in/2012/01/one1secondtimedelayfordigital.htmlThereisalotyoucandowiththisIC,sinceyougetatimeelementintoyourcircuitsusingthisIC.Youcanbuildclocks,timers,stopwatches.ThedifferencebetweenthisICandanoscillatoristhatyoucangetanyfrequencywiththis,butwithanoscillator,youcangetonlyspecificfrequencies.
http://electrotech4u.blogspot.in/2012/01/one-1-second-time-delay-for-digital.html
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CentreforInnovationIndianInstituteofTechnologyMadras
OptoCoupler
Thisisaninterestingcircuitelement,usingthiswecanisolatecircuitsieseparateHighloadandLowloadcircuits.Itisanotherswitch,similartohowTransistorsandMOSFETswork,buttheadvantagethatwegethereisthatthe2circuitshavenowaytointeractdirectly,sinceitworkswhenlightgeneratedbypluggingintoonecircuitdrivestheothercircuit.ThisiscalledOptoisolation.
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CentreforInnovationIndianInstituteofTechnologyMadras
Sometoolsthatyouwillneed:
Wirestripper
DigitalMultimeterHereisalistofbasicfunctionsthatyoucandowithamultimeterhttp://www.thomasnet.com/articles/engineeringconsulting/digitalmultimeters
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CentreforInnovationIndianInstituteofTechnologyMadras
Whattodonext?Thesimplestwaytostartintoelectronicsistogoinanddosomething,getyourhandsdirty.Sogetstarted,buildyourfirstcircuit.Somebasiccircuitswhichyoucanstartwith:
http://www.eleccircuit.com/simpleelectroniccircuits/
http://www.circuitstoday.com/simpleelectronicsprojectsandcircuits
Allthecomponentsinthesecircuitsmightntbediscussedhere,thisistojustgiveyouaheadstart!Allthebest!
http://www.eleccircuit.com/simple-electronic-circuits/http://www.circuitstoday.com/simple-electronics-projects-and-circuits
