#URTIS-ANUAL
OS
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#ONDUCTEDPATHSARECREATEDBYTHEWIRESCONNECTEDTOTHECONTROLLER
4HESEWIRESACTASANTENNASANDTHEAMOUNTOF2&ENERGYCOUPLEDINTOTHEM
ISGENERALLYPROPORTIONALTOTHEIRLENGTH4HE2&VOLTAGESANDCURRENTSINDUCED
INEACHWIREAREAPPLIEDTOTHECONTROLLERPINTOWHICHTHEWIREISCONNECTED
#URTIS CONTROLLERS INCLUDE BYPASS CAPACITORS ON THE PRINTED CIRCUIT BOARDS
THROTTLEWIRESTOREDUCETHEIMPACTOFTHIS2&ENERGYONTHEINTERNALCIRCUITRY
)NSOMEAPPLICATIONSADDITIONALlLTERINGINTHEFORMOFFERRITEBEADSMAYALSO
BEREQUIREDONVARIOUSWIRESTOACHIEVEDESIREDPERFORMANCELEVELS
2ADIATEDPATHSARECREATEDWHENTHECONTROLLERCIRCUITRYISIMMERSEDIN
ANEXTERNALlELD4HISCOUPLINGCANBEREDUCEDBYPLACINGTHECONTROLLERASFAR
ASPOSSIBLEFROMTHENOISESOURCEORBYENCLOSINGTHECONTROLLERINAMETALBOX
3OME#URTISCONTROLLERSAREENCLOSEDBYAHEATSINKTHATALSOPROVIDESSHIELDING
AROUNDTHECONTROLLERCIRCUITRYWHILEOTHERSAREPARTIALLYSHIELDEDORUNSHIELDED
)NSOMEAPPLICATIONSTHEVEHICLEDESIGNERWILLNEEDTOMOUNTTHECONTROLLER
WITHINASHIELDEDBOXONTHEENDPRODUCT4HEBOXCANBECONSTRUCTEDOFJUST
ABOUTANYMETALALTHOUGHSTEELANDALUMINUMAREMOSTCOMMONLYUSED
-OSTCOATEDPLASTICSDONOTPROVIDEGOODSHIELDINGBECAUSETHECOATINGS
ARENOTTRUEMETALSBUTRATHERAMIXTUREOFSMALLMETALPARTICLESINANONCON
DUCTIVEBINDER4HESERELATIVELYISOLATEDPARTICLESMAYAPPEARTOBEGOODBASED
ONADCRESISTANCEMEASUREMENTBUTDONOTPROVIDEADEQUATEELECTRONMOBILITY
TOYIELDGOODSHIELDINGEFFECTIVENESS%LECTROLESSPLATINGOFPLASTICWILLYIELDA
TRUE METAL AND CAN THUS BE EFFECTIVE AS AN 2& SHIELD BUT IT IS USUALLY MORE
EXPENSIVETHANTHECOATINGS
!CONTIGUOUSMETALENCLOSUREWITHOUTANYHOLESORSEAMSKNOWNASA
&ARADAYCAGEPROVIDESTHEBESTSHIELDINGFORTHEGIVENMATERIALANDFREQUENCY
7HENAHOLEORHOLESAREADDED2&CURRENTSmOWINGONTHEOUTSIDESURFACEOF
THESHIELDMUSTTAKEALONGERPATHTOGETAROUNDTHEHOLETHANIFTHESURFACE
WASCONTIGUOUS!SMOREhBENDINGvISREQUIREDOFTHESECURRENTSMOREENERGY
ISCOUPLEDTOTHEINSIDESURFACEANDTHUSTHESHIELDINGEFFECTIVENESSISREDUCED
4HEREDUCTIONINSHIELDINGISAFUNCTIONOFTHELONGESTLINEARDIMENSIONOFA
HOLERATHERTHANTHEAREA4HISCONCEPTISOFTENAPPLIEDWHEREVENTILATIONIS
NECESSARYINWHICHCASEMANYSMALLHOLESAREPREFERABLETOAFEWLARGERONES
!PPLYINGTHISSAMECONCEPTTOSEAMSORJOINTSBETWEENADJACENTPIECESOR
SEGMENTSOFASHIELDEDENCLOSUREITISIMPORTANTTOMINIMIZETHEOPENLENGTH
OFTHESESEAMS3EAMLENGTHISTHEDISTANCEBETWEENPOINTSWHEREGOODOHMIC
CONTACT IS MADE4HIS CONTACT CAN BE PROVIDED BY SOLDER WELDS OR PRESSURE
CONTACT)FPRESSURECONTACTISUSEDATTENTIONMUSTBEPAIDTOTHECORROSION
CHARACTERISTICSOFTHESHIELDMATERIALANDANYCORROSIONRESISTANTPROCESSESAPPLIED
TOTHEBASEMATERIAL)FTHEOHMICCONTACTITSELFISNOTCONTINUOUSTHESHIELDING
EFFECTIVENESSCANBEMAXIMIZEDBYMAKINGTHEJOINTSBETWEENADJACENTPIECES
OVERLAPPINGRATHERTHANABUTTED
4HESHIELDINGEFFECTIVENESSOFANENCLOSUREISFURTHERREDUCEDWHENAWIRE
PASSESTHROUGHAHOLEINTHEENCLOSURE2&ENERGYONTHEWIREFROMANEXTERNAL
lELDISRERADIATEDINTOTHEINTERIOROFTHEENCLOSURE4HISCOUPLINGMECHANISM
CANBEREDUCEDBYlLTERINGTHEWIREWHEREITPASSESTHROUGHTHESHIELDBOUNDARY
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