Idizayini ye-EMC ku PCB ibhodi kufanele kube yingxenye yomklamo obanzi wanoma iyiphi idivayisi ye-elekthronikhi nohlelo, futhi kubiza kakhulu kunezinye izindlela ezizama ukwenza umkhiqizo ufinyelele ku-EMC. Ubuchwepheshe obuyinhloko bomklamo wokuhambisana kwe-electromagnetic wucwaningo lwemithombo yokuphazamiseka kagesi. Ukulawula ukukhishwa kwe-electromagnetic emithonjeni yokuphazamiseka kwe-electromagnetic kuyisixazululo saphakade. Ukulawula ukukhishwa kwemithombo yokuphazamiseka, ngaphezu kokunciphisa izinga lomsindo we-electromagnetic okhiqizwa umshini wemithombo yokuphazamiseka kagesi, ukuvikela (okubandakanya ukuzihlukanisa), ukuhlunga, kanye nobuchwepheshe bokumisa phansi kudingeka busetshenziswe kabanzi.

Izindlela eziyinhloko zokuklama ze-EMC zifaka izindlela zokuvikela i-electromagnetic, amasu okuhlunga isekethe, kanye nokunakwa okukhethekile kufanele kukhokhwe ekwakhiweni kwesisekelo kokugqagqana kwento ephansi.

Okokuqala, iphiramidi yokuklama ye-EMC ebhodini le-PCB
Umfanekiso 9-4 ubonisa indlela enconyiwe yedizayini ye-EMC engcono kakhulu yamadivayisi namasistimu. Lena igrafu yepyramidal.

Okokuqala, isisekelo sokuklama okuhle kwe-EMC ukusetshenziswa kwezimiso ezinhle zokuklama zikagesi nezemishini. Lokhu kuhlanganisa ukucatshangelwa kokuthembeka, okufana nokucaciswa kwedizayini yomhlangano ngaphakathi kokubekezelelana okwamukelekayo, izindlela zokuhlanganisa ezinhle, nezindlela ezihlukahlukene zokuhlola ezisathuthukiswayo.

Ngokuvamile, izisetshenziswa ezishayela okokusebenza kwe-elekthronikhi zanamuhla kufanele zifakwe ku-PCB. Lawa madivayisi akhiwe izingxenye namasekhethi anemithombo engaba khona yokuphazamiseka futhi azwelayo kumandla kazibuthe kagesi. Ngakho-ke, ukwakheka kwe-EMC kwe-PCB yinkinga elandelayo ebaluleke kakhulu ekwakhiweni kwe-EMC. Indawo yezingxenye ezisebenzayo, umzila wemigqa ephrintiwe, ukufaniswa kwe-impedance, ukwakheka kwendawo, kanye nokuhlunga kwesekethe konke kufanele kucatshangelwe ngesikhathi sokuklanywa kwe-EMC. Ezinye izingxenye ze-PCB nazo zidinga ukuvikelwa.

Okwesithathu, izintambo zangaphakathi ngokuvamile zisetshenziselwa ukuxhuma ama-PCB noma ezinye izingxenye ezincane zangaphakathi. Ngakho-ke, idizayini ye-EMC yekhebula yangaphakathi ehlanganisa indlela yomzila nokuvikela kubaluleke kakhulu ku-EMC iyonke yanoma iyiphi idivayisi enikeziwe.

Ungawenza kanjani ukwakheka kwe-EMC ebhodini le-PCB?

Ngemuva kokuthi umklamo we-EMC we-PCB kanye nomklamo wekhebula wangaphakathi usuqediwe, ukunakwa okukhethekile kufanele kukhokhwe ekwakhiweni kokuvikela i-chassis nezindlela zokucubungula zazo zonke izikhala, ama-perforations kanye nekhebula ngokusebenzisa izimbobo.

Okokugcina, kufanele futhi kugxile ekunikezeni amandla okokufaka nokuphumayo nezinye izinkinga zokuhlunga ikhebula.

2. Electromagnetic shielding
Ukuvikela ikakhulukazi kusebenzisa izinto ezisetshenziswayo ezihlukahlukene, ezakhiwe zaba amagobolondo ahlukahlukene futhi axhunywe emhlabeni ukuze anqamule indlela yokusakazwa komsindo we-electromagnetic eyakhiwe ngokuhlangana kwe-electrostatic, ukuhlangana kwe-inductive noma ukuxhumanisa insimu ye-electromagnetic endaweni. Ukuhlukaniswa kusetshenziswa ikakhulukazi ama-relay, ama-isolation transformers noma ama-Isolators e-photoelectric kanye namanye amadivaysi ukunqamula indlela yokusakazwa komsindo we-electromagnetic ngendlela yokuqhuba abonakala ngokuhlukanisa uhlelo lomhlabathi lwezingxenye ezimbili zesekethe kanye nokunqamula ithuba lokuhlangana. i-impedance.

Ukuphumelela kwendikimba evikelayo imelelwa ukusebenza kahle kokuvikela (SE) (njengoba kuboniswe kuMfanekiso 9-5). Ukusebenza kokuvikela kuchazwa ngokuthi:

Ungawenza kanjani ukwakheka kwe-EMC ebhodini le-PCB?

Ubudlelwano phakathi kokuphumelela kokuvikela ugesi kanye nokuncishiswa kwamandla enkambu kufakwe kuhlu kuThebula 9-1.

Ungawenza kanjani ukwakheka kwe-EMC ebhodini le-PCB?

Uma kuphezulu ukusebenza kahle kokuvikela, kuba nzima kakhulu ekukhuphukeni ngakunye okungu-20dB. Icala lezinto zokusebenza zomphakathi ngokuvamile lidinga kuphela ukusebenza kahle kokuvikela okungaba ngu-40dB, kuyilapho icala lempahla yezempi ngokuvamile lidinga ukusebenza kahle kokuvikela okungaphezu kuka-60dB.

Izinto ezine-conductivity ephezulu kagesi kanye nokungena kazibuthe zingasetshenziswa njengezinto zokuvikela. Izinto ezisetshenziswa kakhulu zokuvikela ipuleti lensimbi, ipuleti le-aluminium, ucwecwe lwe-aluminium, ipuleti lethusi, ucwecwe lwethusi nokunye. Ngezidingo eziqinile zokuhambisana kozibuthe zikagesi zemikhiqizo yabantu, bayanda abakhiqizi abasebenzisa indlela yokufaka i-nickel noma ithusi ekesini lepulasitiki ukuze bavikeleke.

PCB design, sicela uthinte 020-89811835

Okwesithathu, ukuhlunga
Ukuhlunga kuyindlela yokucubungula umsindo we-electromagnetic esizindeni samafrikhwensi, okuhlinzeka ngendlela ephansi yokuvimbela umsindo we-electromagnetic ukufeza inhloso yokucindezela ukuphazamiseka kwe-electromagnetic. Sika indlela ukuphazamiseka okuyisabalalisa emugqeni wesignali noma ulayini wamandla, futhi ukuvikela ndawonye kwakha isivikelo esiphelele sokuphazamiseka. Isibonelo, isihlungi sokuphakelwa kwamandla sethula ukuvinjelwa okuphezulu kufrikhwensi yamandla engu-50 Hz, kodwa sethula ukuphazamiseka okuphansi kububanzi bomsindo we-electromagnetic.

Ngokwezinto ezihlukene zokuhlunga, isihlungi sihlukaniswe ngesihlungi samandla e-AC, isihlungi somugqa wokudlulisa isignali nesihlungi sokuhlukanisa. Ngokusho kwebhendi yefrikhwensi yesihlungi, isihlungi singahlukaniswa sibe izinhlobo ezine zezihlungi: i-low-pass, high-pass, i-band-pass, ne-band-stop.

Ungawenza kanjani ukwakheka kwe-EMC ebhodini le-PCB?

Okwesine, ukunikezwa kwamandla kagesi, ubuchwepheshe bokumisa phansi
Noma ngabe imishini yobuchwepheshe bolwazi, i-radio electronics, kanye nemikhiqizo kagesi, kufanele inikezwe amandla umthombo wamandla. Ukunikezwa kwamandla kuhlukaniswe amandla angaphandle kanye nokunikezwa kwamandla kwangaphakathi. Ukunikezwa kwamandla kuwumthombo ojwayelekile futhi ongathi sína wokuphazamiseka kazibuthe kagesi. Njengomthelela wegridi yamandla, i-voltage ephezulu ingaba phezulu njengama-kilovolts noma ngaphezulu, okuzodala umonakalo odabukisayo kumishini noma ohlelweni. Ukwengeza, intambo kagesi eyinhloko iyindlela yezibonakaliso ezihlukahlukene zokuphazamiseka ukuze zihlasele imishini. Ngakho-ke, uhlelo lokuphakela amandla, ikakhulukazi umklamo we-EMC wokushintshwa kwamandla kagesi, luyingxenye ebalulekile yomklamo wezinga lengxenye. Izinyathelo zihlukahlukene, njengokuthi ikhebula lokuphakela amandla lidonswa ngokuqondile esangweni elikhulu legridi yamandla, i-AC ethathwe kugridi yamandla iqiniswa, ukuhlunga okudlula kancane, ukuhlukaniswa phakathi kwama-windings okuguqula amandla, ukuvikela, ukucindezelwa kokukhuphuka, kanye nokuvikelwa kwe-overvoltage kanye ne-overcurrent.

Ukubeka phansi kuhlanganisa ukubeka phansi, ukubeka isignali, nokunye. Idizayini yomzimba ophansi, ukwakheka kwentambo yaphansi, kanye nokuvinjwa kwentambo yaphansi kumafrikhwensi ahlukahlukene akuhlobene kuphela nokuphepha kukagesi komkhiqizo noma uhlelo, kodwa futhi kuhlobene nokuhambisana kwe-electromagnetic kanye nobuchwepheshe bayo bokulinganisa.

Ukuzibekela phansi okuhle kungavikela ukusebenza okuvamile kwemishini noma isistimu nokuphepha komuntu siqu, futhi kungaqeda ukuphazamiseka okuhlukahlukene kombani kanye nokushaywa kombani. Ngakho-ke, ukwakheka komhlaba kubaluleke kakhulu, kodwa futhi kuyindaba enzima. Kunezinhlobo eziningi zezintambo eziphansi, okuhlanganisa indawo enengqondo, indawo yesignali, indawo yesihlangu, nendawo yokuvikela. Izindlela zokubeka phansi zingahlukaniswa zibe isisekelo esinephuzu elilodwa, indawo enamaphuzu amaningi, isisekelo esixubile kanye nomhlabathi ontantayo. Indawo esezingeni eliphansi kufanele ibe ku-zero, futhi awukho umehluko ongaba khona phakathi kwamaphoyinti okuphansi. Kodwa empeleni, noma yikuphi “umhlabathi” noma ucingo oluphansi lunokumelana. Lapho ukugeleza kwamanje, ukwehla kwe-voltage kuzokwenzeka, ukuze amandla ocingweni lwaphansi angabi ngu-zero, futhi kuzoba ne-voltage yomhlabathi phakathi kwamaphuzu amabili aphansi. Uma isifunda sisekelwe ezindaweni eziningi futhi kukhona ukuxhumana kwesignali, izokwakha i-voltage yokuphazamiseka kwe-loop yomhlaba. Ngakho-ke, ubuchwepheshe be-grounding bukhethekile kakhulu, njengokugxilisa isignali kanye nokubeka phansi kwamandla kufanele kuhlukaniswe, amasekhethi ayinkimbinkimbi asebenzisa isisekelo samaphuzu amaningi kanye nesisekelo esivamile.