izindaba

Emhlabeni wethu okahle, ukuphepha, ikhwalithi nokusebenza kubaluleke kakhulu. Nokho, ezimweni eziningi, izindleko zengxenye yokugcina, kuhlanganise ne-ferrite, sekuyiyona nto enqumayo.Le ndatshana ihloselwe ukusiza onjiniyela abaklami bathole ezinye izinto zokwakha ze-ferrite ukuze banciphise. izindleko.
Izakhiwo ze-intrinsic material ezifiselekayo kanye ne-core geometry zinqunywa uhlelo ngalunye oluthile.Izici ezingokwemvelo ezilawula ukusebenza kwezinga lesignali eliphansi ukungeneka (ikakhulukazi izinga lokushisa), ukulahlekelwa okuyisisekelo okuphansi, nokuzinza okuhle kazibuthe ngokuhamba kwesikhathi nezinga lokushisa.Izicelo zihlanganisa i-high-Q. ama-inductors, ama-inductors emodi evamile, i-broadband, ama-matched and pulse transformers, izakhi ze-antenna zomsakazo, neziphindaphindayo ezisebenzayo nezingenzi lutho.Ezisetshenziswa zamandla, ukuminyana okuphezulu okuguquguqukayo nokulahlekelwa okuphansi kumafrikhwensi okusebenza kanye nezinga lokushisa kuyizici ezifiselekayo.Izicelo zihlanganisa amandla emodi yokushintsha ukushaja ibhethri lemoto kagesi, izikhulisamandla kazibuthe, iziguquli ze-DC-DC, izihlungi zamandla, amakhoyili okuthungela, nama-transformer.
Isakhiwo sangaphakathi esinomthelela omkhulu ekusebenzeni kwe-ferrite ethambile ekucindezelweni kwezicelo ukungeneka okuyinkimbinkimbi [1], okulinganayo nokubambezeleka kwengqikithi.Kunezindlela ezintathu zokusebenzisa i-ferrite njengomcindezeli wamasiginali angafuneki (okwenziwa noma okukhipha imisebe ).Okokuqala, futhi okungajwayelekile kangako, kunjengesihlangu esisebenzayo, lapho ama-ferrite esetshenziswa khona ukuhlukanisa amakhondatha, izingxenye noma amasekhethi endaweni ekhipha imisebe ye-electromagnetic field.Ekusetshenzisweni kwesibili, ama-ferrite asetshenziswa nama-elementi e-capacitive ukuze enze ukudlula okuphansi. isihlungi, okungukuthi inductance - capacitive at low frequencies and dissipation at high frequencies.Okwesithathu futhi okuvamile ukusetshenziswa yilapho ama-ferrite cores asetshenziswa yedwa ezingxenyeni zokuhola noma amasekethe ezinga lebhodi.Kulolu hlelo lokusebenza, inkaba ye-ferrite ivimbela noma yikuphi ukuzulazula kwe-parasitic kanye/ noma inciphise ukulandwa kwesignali okungafunwa noma ukudluliselwa okungase kusakaze eduze komkhondo wengxenye noma ukuxhumana, ukulandelelwa noma izintambo.Ohlelweni lwesibili nolwesithathu, ama-ferrite cores acindezela i-EMI eyenziwa ngokuqeda noma ngokunciphisa kakhulu amaza aphezulu adonswa imithombo ye-EMI. Ukwethulwa kwe-ferrite kunikeza I-impedance ephezulu ngokwanele yokucindezela amaza omoya aphezulu. Ngokombono, i-ferrite ekahle inganikeza ukuvinjelwa okuphezulu kumafrikhwensi we-EMI kanye ne-zero impedance kuwo wonke amanye ama-frequencies. I-impedance ephezulu ingatholakala phakathi kuka-10 MHz no-500 MHz kuye ngokuthi i-ferrite material.
Njengoba ihambisana nezimiso zobunjiniyela bukagesi, lapho amandla kagesi e-AC kanye namanje amelelwa amapharamitha ayinkimbinkimbi, ukufinyeleleka kwento ethile kungavezwa njengepharamitha eyinkimbinkimbi ehlanganisa izingxenye zangempela nezicatshangelwayo. Ingxenye yangempela (μ') imele ingxenye esebenzayo, esesigabeni esinendawo kazibuthe eshintshanayo [2], kuyilapho ingxenye ecatshangelwayo (μ”) imelela ukulahlekelwa, okungaphandle kwesigaba inkambu kazibuthe eshintshanayo.Lezi zingavezwa njengezingxenye zochungechunge (μs'μs”) noma engxenyeni efanayo (µp'µp”).Amagrafu ku-Figure 1, 2, kanye no-3 abonisa izingxenye zochungechunge lwe-permeability yokuqala eyinkimbinkimbi njengomsebenzi wokuvama kwezinto ezintathu ze-ferrite.Uhlobo lwezinto ezingu-73 yi-ferrite ye-manganese-zinc, i-magnetic yokuqala I-conductivity ingu-2500. Uhlobo lwe-Material 43 i-nickel zinc ferrite enokungena kokuqala okungu-850. Uhlobo lwe-Material 61 yi-nickel zinc ferrite enokungena kokuqala okungu-125.
Ngokugxila engxenyeni yochungechunge lwempahla yoHlobo lwe-61 ku-Figure 3, sibona ukuthi ingxenye yangempela yokungena, μs', ihlala njalo nemvamisa ekhulayo kuze kufinyelelwe imvamisa ebalulekile, bese yehla ngokushesha.Ukulahlekelwa noma u-μs” kukhuphuka bese iphakama njengokuwa kuka-μs.Lokhu kuncipha ku-μs kungenxa yokuqala kwe-ferrimagnetic resonance.[3] Kufanele kuqashelwe ukuthi ukuphakama kokungena kuphezulu, kulapho kuyancipha imvamisa.Lobu budlelwano obuphambene baqale babonwa ngu-Snoek futhi banikeza ifomula elandelayo:
lapho: ƒres = μs” imvamisa ephezulu γ = isilinganiso se-gyromagnetic = 0.22 x 106 A-1 m μi = ukungena kokuqala kwe-Msat = 250-350 Am-1
Njengoba ama-ferrite cores asetshenziswa ezingeni eliphansi lesignali kanye nezinhlelo zokusebenza zamandla zigxila kumapharamitha kazibuthe angaphansi kwalesi mvamisa, abakhiqizi be-ferrite abavamile ukushicilela idatha yokufinyeleleka kanye/noma yokulahlekelwa kumafrikhwensi aphezulu.Nokho, idatha yemvamisa ephezulu ibalulekile lapho kucaciswa ama-ferrite cores ekucindezelweni kwe-EMI.
Isici abakhiqizi abaningi be-ferrite abasicacisayo sezingxenye ezisetshenziselwa ukucindezelwa kwe-EMI ukuvinjelwa. Ukuphazamiseka kukalwa kalula kusihlaziyi esitholakalayo esithengiswayo esinokufundwa kwedijithali okuqondile. Ngeshwa, i-impedance ivamise ukucaciswa ngefrikhwensi ethile futhi iyisikala esimelela ubukhulu benkimbinkimbi. I-Impedans Vector
Kodwa ngisho nangaphambi kokuqala ukwenza imodeli yokusebenza kwezingxenye ze-ferrite kusekethe, abaklami kufanele bazi lokhu okulandelayo:
lapho μ'= ingxenye yangempela yokungena okuyinkimbinkimbi μ”= ingxenye ecatshangelwayo yokungena okuyinkimbinkimbi j = i-vector ecatshangelwayo yeyunithi Lo= inductance yomoya
I-impedance ye-iron core nayo ibhekwa njengenhlanganisela yochungechunge lwe-inductive reactance (XL) kanye nokumelana nokulahlekelwa (Rs), kokubili okuncike emazingeni.Ingqikithi engalahleki izoba nesithintelo esinikezwe ukusabela:
lapho: ama-Rs = ukumelana nochungechunge oluphelele = Rm + Re Rm = ukumelana nochungechunge okulingana ngenxa yokulahlekelwa kazibuthe Re = ukumelana nochungechunge olulinganayo lokulahlekelwa kwethusi
Emazansi aphansi, i-impedance yengxenye ngokuyinhloko i-inductive.Njengoba imvamisa inyuka, i-inductance iyancipha ngenkathi ukulahlekelwa kukhuphuka futhi i-impedance ephelele iyanda.Umfanekiso 4 uyisakhiwo esivamile se-XL, i-Rs kanye ne-Z ngokumelene nemvamisa yezinto zethu zokufinyelela okuphakathi. .
Khona-ke ukusabela kwe-inductive kuhambisana nengxenye yangempela yokufinyeleleka okuyinkimbinkimbi, ngo-Lo, i-air-core inductance:
Ukumelana nokulahlekelwa kuphinde kulingane nengxenye ecatshangelwayo yokungena okuyinkimbinkimbi ngokuqhubekayo okufanayo:
Ku-Equation 9, i-core material inikezwa ngo-µs' no-µs”, futhi i-core geometry inikezwa ngu-Lo.Ngakho-ke, emva kokwazi ukungena okuyinkimbinkimbi kwama-ferrite ahlukene, ukuqhathanisa kungenziwa ukuze kutholwe into efaneleke kakhulu kulokho okufunayo. imvamisa noma ububanzi befrikhwensi.Ngemva kokukhetha into engcono kakhulu, sekuyisikhathi sokukhetha izingxenye zesayizi ezingcono kakhulu.Ukumelwa kwe-vector kokungena okuyinkimbinkimbi kanye nokuvinjwa kuboniswa kuMfanekiso 5.
Ukuqhathaniswa komumo oyinhloko kanye nezinto eziyinhloko zokuthuthukisa i-impedance kuqondile uma umenzi ehlinzeka ngegrafu yokufinyeleleka okuyinkimbinkimbi ngokumelene nemvamisa yezinto ze-ferrite ezinconyelwe izinhlelo zokusebenza zokucindezelwa.Ngeshwa, lolu lwazi aluvamile ukutholakala. ama-curves.Kusuka kule datha ukuqhathaniswa kwezinto ezisetshenziselwa ukuthuthukisa i-impedance eyinhloko ingatholwa.
Kubhekiselwa kuMdwebo 6, ukuvunyelwa kokuqala kanye nesici sokulahla [4] sezinto ezibonakalayo ze-Fair-Rite 73 uma kuqhathaniswa nemvamisa, kucatshangwa ukuthi umklami ufuna ukuqinisekisa ukuthikamezeka okukhulu phakathi kuka-100 no-900 kHz.73 kukhethiwe. Ngezinjongo zokumodela, umklami naye idinga ukuqonda izingxenye ezisebenzayo neziqinile ze-impedance vector ku-100 kHz (105 Hz) kanye no-900 kHz. Lolu lwazi lungatholakala eshadini elilandelayo:
Ku-100kHz μs ' = μi = 2500 futhi (Tan δ / μi) = 7 x 10-6 ngenxa yokuthi u-Tan δ = μs ”/ μs' bese u-μs” = (Tan δ / μi) x (μi) 2 = 43.8
Kufanele kuqashelwe ukuthi, njengoba kulindelekile, i-μ” yengeza okuncane kakhulu ku-vector isiyonke yokungena kule mvamisa ephansi.I-impedance ye-core ngokuvamile i-inductive.
Abaklami bayazi ukuthi ingqikithi kufanele yamukele intambo engu-#22 futhi ingene endaweni engu-10 mm x 5 mm. Ububanzi bangaphakathi buzocaciswa njengo-0.8 mm. 10 mm nobude 5 mm:
Z= ωLo (2500.38) = (6.28 x 105) x .0461 x log10 (5/.8) x 10 x (2500.38) x 10-8= 5.76 ohms ngo-100 kHz
Kulesi simo, njengezikhathi eziningi, ukuvinjelwa okukhulu kufinyelelwa ngokusebenzisa i-OD encane enobude obude.Uma i-ID inkulu, isb. 4mm, ngokuphambene nalokho.
Indlela efanayo ingasetshenziswa uma iziza ze-impedance ngayinye yeyunithi Lo kanye ne-engeli yesigaba ngokumelene ne-frequency kunikezwa.Amanani 9, 10 kanye no-11 amelela amajika anjalo ezintweni ezintathu ezifanayo ezisetshenziswe lapha.
Abaklami bafuna ukuqinisekisa ukuthikamezeka okukhulu kunobubanzi obungu-25 MHz kuya ku-100 MHz. Isikhala sebhodi esitholakalayo futhi singu-10mm x 5mm futhi umgogodla kufanele wamukele intambo engu-#22 ye-awg. Ngokubhekisela kuMfanekiso 7 weyunithi ye-impedance Lo yezinto ezintathu ze-ferrite, noma Umfanekiso 8 wokungena okuyinkimbinkimbi kwezinto ezintathu ezifanayo, khetha into engu-850 μi.[5]Kusetshenziswa igrafu kuMfanekiso 9, i-Z/Lo yezinto ezingeneka okumaphakathi ngu-350 x 108 ohm/H ngo-25 MHz. Xazulula ukuvimbela okulinganiselwe:
Ingxoxo eyanduleleyo ithatha ngokuthi umnyombo wokukhetha uyisilinda. Uma ama-ferrite cores esetshenziselwa izintambo zamaribhoni ayisicaba, izintambo eziboshiwe, noma amapuleti anembobo, ukubala kwe-Lo kuba nzima kakhulu, futhi ubude bendlela obunembe ngokufanele kanye nezibalo zendawo ezisebenzayo kufanele kutholwe. ukubala i-air core inductance .Lokhu kungenziwa ngokusika umgogodla ngokwezibalo bese wengeza ubude bendlela obaliwe kanye nendawo kazibuthe kucezu ngalunye.Kuzo zonke izimo, nokho, ukwanda noma ukwehla kwe-impedance kuzolingana nokwanda noma ukuncipha ukuphakama/ubude benkango ye-ferrite.[6]
Njengoba kushiwo, abakhiqizi abaningi bacacisa ama-cores wezinhlelo zokusebenza ze-EMI ngokuya nge-impedance, kodwa umsebenzisi wokugcina ngokuvamile udinga ukwazi ukuncishiswa.Ubudlelwano obukhona phakathi kwala mapharamitha amabili yilokhu:
Lobu budlelwano buncike ekuphazamisekeni komthombo odala umsindo kanye nokuthikamezeka komthwalo othola umsindo.Lawa manani ngokuvamile ayizinombolo eziyinkimbinkimbi, ububanzi bazo bungapheli, futhi azitholakali kalula kumklami. Ukukhetha inani 1 ohm ngomthwalo kanye nokuvinjelwa komthombo, okungenzeka uma umthombo uwumthombo wamandla wemodi yokushintsha futhi ulayisha amasekhethi amaningi aphansi, yenza izibalo zibe lula futhi uvumele ukuqhathanisa ukuncishiswa kwama-ferrite cores.
Igrafu ekuMfanekiso 12 iqoqo lamajika abonisa ubudlelwano phakathi kokubambezeleka kobuhlalu besihlangu kanye nokuncishiswa kwamanani amaningi ajwayelekile omthwalo kanye nokubambezeleka kwejeneretha.
Umfanekiso 13 umjikelezo olinganayo womthombo wokuphazamiseka onokuphikiswa kwangaphakathi kwama-Z.Isiginali yokuphazamiseka ikhiqizwa uchungechunge lwe-impedance Zsc ye-sppressor core kanye ne-Impedans yomthwalo we-ZL.
Amanani 14 kanye ne-15 amagrafu e-impedance ngokumelene nezinga lokushisa kwezinto ezintathu ezifanayo ze-ferrite.Izinzile kakhulu zalezi zinto yizinto ezingu-61 ezinokunciphisa ngo-8% kokuvinjelwa ku-100º C kanye no-100 MHz. Ngokuphambene, izinto ezingu-43 zibonise u-25 % ukwehla kwezinga lokushisa ngesilinganiso esifanayo kanye nezinga lokushisa.Lawa majika, uma enikeziwe, angasetshenziswa ukulungisa i-impedance yegumbi eshiwo uma kudingeka ukuncipha emazingeni okushisa aphakeme.
Njengezinga lokushisa, i-DC kanye ne-50 noma i-60 Hz yokuhlinzeka ngemisinga iphinde ithinte izakhiwo ze-ferrite zemvelo ezifanayo, eziholela ekubambeni okuphansi okuyinhloko. .Le jika ichaza ukucekelwa phansi kwe-impedance njengomsebenzi wamandla enkambu wento ethile njengomsebenzi wokuvama.Kufanele kuqashelwe ukuthi umphumela wokuchema uyancipha njengoba imvamisa inyuka.
Selokhu kwahlanganiswa le datha, i-Fair-Rite Products yethule izinto ezimbili ezintsha.Okwethu i-44 iwumsebenzi we-nickel-zinc medium permeability futhi i-31 yethu iwumsebenzi we-manganese-zinc ophezulu okwazi ukungena.
Umfanekiso we-19 uyisakhiwo se-impedance ngokumelene nemvamisa yobuhlalu obunobukhulu obufanayo ezintweni ezingu-31, 73, 44 kanye ne-43. Impahla engu-44 iyimpahla ethuthukisiwe engu-43 ene-DC resistivity ephakeme, i-109 ohm cm, izakhiwo ezingcono zokushaqeka okushisayo, ukuzinza kwezinga lokushisa kanye izinga lokushisa eliphezulu le-Curie (Tc).Into engu-44 inezinto eziphakeme kancane eziqhathaniswa nezici zokuvama uma kuqhathaniswa nokokusebenza kwethu okungu-43. Impahla enganyakazi 31 ibonisa ukuthikamezeka okuphezulu kunama-43 noma ama-44 kulo lonke uhla lwamafrikhwensi okulinganisa. I-31 yakhelwe ukudambisa Inkinga ye-dimensional resonance ethinta ukusebenza kwefrequency ephansi yokucindezela kwama-manganese-zinc cores amakhulu futhi isetshenziswe ngempumelelo kuma-cable connector suppression cores nama-toroidal cores amakhulu. -Rite cores nge-0.562″ OD, 0.250 ID, kanye ne-1.125 HT.Uma uqhathanisa Umfanekiso 19 kanye noMfanekiso 20, kufanele kuqashelwe ukuthi Kuma-cores amancane, kumafrikhwensi afika ku-25 MHz, impahla engu-73 iyona nto engcono kakhulu yokucindezela.Kodwa-ke, njengoba isigaba sesiphambano esiyinhloko sikhula, imvamisa ephezulu iyancipha.Njengoba kukhonjisiwe kudatha kuMfanekiso 20, 73 iyona engcono kakhulu Imvamisa ephezulu kakhulu ngu-8 MHz.Kuyaqapheleka futhi ukuthi izinto ezingama-31 zisebenza kahle ebangeni lemvamisa ukusuka ku-8 MHz kuye ku-300 MHz.Kodwa-ke, njenge-ferrite ye-manganese zinc, into engu-31 inomthamo ophansi kakhulu wokuphikisa we-102 ohms -cm, kanye nezinguquko eziningi ze-impedance ngokushintsha okukhulu kwezinga lokushisa.
I-Glossary Air Core Inductance – Lo (H) I-inductance ebizokalwa uma umgogodla ubunokufinyeleleka okufanayo kanye nokusabalalisa kwe-flux kuhlala kungashintshi.Ifomula evamile Lo= 4π N2 10-9 (H) C1 Ring Lo = .0461 N2 log10 (OD /ID) Ht 10-8 (H) Ubukhulu ngama-mm
I-Attenuation - A (dB) Ukuncishiswa kwe-amplitude yesignali ekudluliselweni kusuka endaweni eyodwa kuya kwelinye.Kuyisilinganiso sesikala se-amplitude yokufaka kuya ku-amplitude ephumayo, ngama-decibel.
I-Core Constant – C1 (cm-1) Isamba sobude bendlela kazibuthe yesigaba ngasinye sesekethe kazibuthe ehlukaniswa yisifunda kazibuthe esihambisanayo sesigaba esifanayo.
I-Core Constant – C2 (cm-3) Isamba sobude bomjikelezo kazibuthe wesigaba ngasinye sesekethe kazibuthe ehlukaniswa yisikwele sesizinda kazibuthe esihambisanayo sesigaba esifanayo.
Ubukhulu obusebenzayo bendawo kazibuthe u-Ae (cm2), ubude bendlela le (cm) kanye nevolumu ye-Ve (cm3) Kujiyomethri ewumgogodla enikeziwe, kucatshangwa ukuthi ubude bendlela kazibuthe, indawo enqamulayo, kanye nevolumu i-toroidal core inezinto ezibonakalayo ezifanayo njengezinto ezibonakalayo kufanele zibe nezakhiwo kazibuthe ezilingana nengqikithi enikeziwe.
Amandla Enkundla – H (Oersted) Ipharamitha ekhombisa ubukhulu bamandla enkundla.H = .4 π NI/le (Oersted)
I-Flux Density – B (Gaussian) Ipharamitha ehambisanayo yenkambu kazibuthe eyenziwe endaweni evamile kumzila ogelezayo.
Ukuthikamezeka – Z (ohm) Ukuthikamezeka kwe-ferrite kungavezwa ngokuya ngokukwazi ukungena kwayo okuyinkimbinkimbi.Z = jωLs + Rs = jωLo(μs'- jμs”) (ohm)
I-Loss Tangent – ​​tan δ I-tangent yokulahlekelwa ye-ferrite ilingana ne-reciprocal yesekethe Q.
I-Loss Factor – tan δ/μi Ukususwa kwesigaba phakathi kwezingxenye ezibalulekile zokuminyana kazibuthe namandla enkambu ngokungena kokuqala.
I-Magnetic Permeability - μ Ukungena kazibuthe okutholakala esilinganisweni sokuminyana kazibuthe kanye namandla enkambu ashintshanayo asetshenziswayo...
I-amplitude permeability, μa – lapho inani elishiwo lokuminyana kwe-flux likhulu kunevelu esetshenziselwa ukufinyeleleka kokuqala.
I-Permeability Esebenzayo, μe - Uma umzila kazibuthe wakhiwe ngesikhala somoya esisodwa noma ngaphezulu, ukungeneka ukungeneka kwento eqanjiwe ye-homogeneous enganikeza ukungabaza okufanayo.
I-In Compliance ingumthombo oyinhloko wezindaba, ulwazi, imfundo kanye nogqozi lochwepheshe bezobunjiniyela bakagesi kanye nobuchwepheshe.
I-Aerospace Automotive Communications Consumer Electronics Education Amandla kanye Nomkhakha Wamandla Wolwazi Lobuchwepheshe Ezokwelashwa Kwezempi Nokuvikela