Kuye kwathiwa kukho iindidi ezimbini kuphela zeenjineli ze-elektroniki ehlabathini: ezo ziye zafumana ukuphazamiseka kombane kunye nezo zingazange zifumaneke.Ngokunyuka kwamaza ophawu lwePCB, uyilo lwe-EMC yingxaki ekufuneka siyiqwalasele
1. Iimpawu ezintlanu ezibalulekileyo ekufuneka ziqwalaselwe ngexesha lohlalutyo lwe-EMC
Ukujongana noyilo, zintlanu iimpawu ezibalulekileyo ekufuneka uziqwalasele xa usenza uhlalutyo lwe-EMC yemveliso kunye noyilo:
1).Ubungakanani besixhobo esingundoqo:
Imilinganiselo ebonakalayo yesixhobo esikhuphayo esivelisa imitha.Irediyo yerediyo (RF) yangoku iya kudala indawo ye-electromagnetic, eya kuvuza kwindlu nangaphandle kwendlu.Ubude bentambo kwi-PCB njengendlela yothumelo inefuthe elithe ngqo kwi-RF yangoku.
2).Ukuthelekisa i-impedance
Umthombo kunye ne-impedances yomamkeli, kunye nokuphazamiseka kokudluliselwa phakathi kwabo.
3).Iimpawu zexeshana zeempawu zokuphazamiseka
Ingaba ingxaki sisehlo esiqhubekayo (umqondiso wexesha), okanye ngumjikelo othile wokusebenza kuphela (umzekelo, isiganeko esinye sinokuba sisitshixo okanye uphazamiseko lwamandla, ukusebenza kwediski ngamaxesha athile, okanye ukugqabhuka kwenethiwekhi)
4).Amandla omqondiso wokuphazamiseka
Unamandla kangakanani umgangatho wamandla omthombo, kwaye ungakanani amandla onawo ukuvelisa ukuphazamiseka okuyingozi
5).Iimpawu zokuphindaphinda kweempawu zokuphazamiseka
Ukusebenzisa i-spectrum analyzer ukujonga i-waveform, jonga apho ingxaki yenzeka khona kwi-spectrum, ekulula ukuyifumana ingxaki.
Ukongeza, eminye imikhwa yoyilo lwesekethe ephantsi ifuna ingqalelo.Umzekelo, isiseko sendawo enye silungele kakhulu usetyenziso lwefrikhwensi ephantsi, kodwa ayifanelanga imiqondiso yeRF apho kukho iingxaki ezininzi ze-EMI.
Kukholelwa ukuba ezinye iinjineli ziya kusebenzisa indawo enye kuyo yonke imveliso yoyilo ngaphandle kokuqaphela ukuba ukusetyenziswa kwale ndlela yokumisa kunokudala iingxaki ezingakumbi okanye ezinzima ze-EMC.
Kufuneka kwakhona sinikele ingqalelo ekuhambeni kwangoku kumacandelo esekethe.Ukususela kulwazi lwesiphaluka, siyazi ukuba i-current flow flowing ukusuka kwi-voltage ephezulu ukuya kwi-voltage ephantsi, kwaye i-current isoloko ihamba ngendlela enye okanye ngaphezulu kwisiphaluka esivaliweyo, ngoko kukho umgaqo obaluleke kakhulu: yila i-loop encinci.
Kwezo zalathiso apho uphazamiseko lwangoku lulinganiswa, i-PCB yocingo iguqulwa ukuze ingachaphazeli umthwalo okanye isiphaluka esibuthathaka.Izicelo ezifuna umendo ophezulu we-impedance ukusuka kunikezelo lwamandla ukuya kumthwalo kufuneka ziqwalasele zonke iindlela ezinokubakho apho imbuyekezo yangoku inokuhamba ngayo.
Kufuneka kwakhona sinikele ingqalelo kwiingcingo zePCB.I-impedance yocingo okanye indlela iqulethe ukuchasana kwe-R kunye ne-inductive reactance.Kwiifrikhwensi eziphezulu, kukho i-impedance kodwa akukho capacitive reactance.Xa i-frequency yocingo ingaphezulu kwe-100kHz, ucingo okanye ucingo luba yi-inductor.Iingcingo okanye iingcingo ezisebenza ngaphezulu kwesandi zinokuba zii-eriyali zeRF.
Kwiinkcukacha ze-EMC, iingcingo okanye iingcingo azivumelekanga ukuba zisebenze ngaphantsi kwe-λ/20 yefrikhwensi ethile (i-eriyali yenzelwe ukuba yi-λ/4 okanye i-λ/2 yefrikhwensi ethile).Ukuba ayiyilwanga ngolo hlobo, i-wiring iba yi-eriyali esebenza kakhulu, nto leyo eyenza ukuba kamva kulungiswe ingxaki nangakumbi.
2.Uyilo lwePCB
Okokuqala: Qwalasela ubungakanani bePCB.Xa ubukhulu be-PCB bukhulu kakhulu, amandla okuchasana nokuphazamiseka kwenkqubo ayancipha kwaye iindleko zinyuka ngokunyuka kwe-wiring, ngelixa ubukhulu buncinci kakhulu, obubangela lula ingxaki yokutshatyalaliswa kobushushu kunye nokuphazamiseka okufanayo.
Okwesibini: misela indawo yamacandelo akhethekileyo (njengezinto zewashi) (i-wiring yewashi ingcono kakhulu ukuba ingabekwa phantsi kwaye ungahambi malunga nemigca yeempawu eziphambili, ukuphepha ukuphazamiseka).
Okwesithathu: ngokuhambelana nomsebenzi wesekethe, ukubekwa kwePCB iyonke.Kwisakhiwo secandelo, amacandelo anxulumeneyo kufuneka asondele ngokusemandleni, ukuze afumane umphumo ongcono wokuchasana nokuphazamiseka.