iindaba

Kwihlabathi lethu elifanelekileyo, ukhuseleko, umgangatho kunye nokusebenza kubaluleke kakhulu.Kwiimeko ezininzi, nangona kunjalo, iindleko zecandelo lokugqibela, kuquka i-ferrite, iye yaba yinto yokumisela.Eli nqaku lijoliswe ekuncedeni iinjineli zokuyila ukufumana ezinye izinto ze-ferrite zokunciphisa. iindleko.
Izinto ezinqwenelekayo zemathiriyeli yangaphakathi kunye nejiyometri engundoqo zimiselwa sisicelo ngasinye.Iimpawu zendalo ezilawula ukusebenza kwizinga eliphantsi lophawu lwezicelo zikwazi ukungena (ingakumbi ubushushu), ilahleko ephantsi, kunye nokuzinza okuhle kwemagnethi ekuhambeni kwexesha kunye nobushushu.Izicelo ziquka i-Q ephezulu. i-inductors, i-inductors yemodi eqhelekileyo, i-broadband, i-match kunye ne-pulse transformers, izinto ze-antenna zerediyo, kunye nokuphindaphinda okusebenzayo kunye nokunyanzeliswa kwezicelo zamandla, ukuxinana okuphezulu kwe-flux kunye nelahleko ephantsi kwi-frequency yokusebenza kunye nobushushu zizinto ezinqwenelekayo.Izicelo ziquka izixhobo zombane zendlela yokutshintsha ukutshaja ibhetri yemoto yombane, izikhulisi zemagnethi, iziguquli zeDC-DC, izihluzi zamandla, iikhoyili zokutshisa, kunye neziguquli.
Ipropathi yangaphakathi enempembelelo enkulu ekusebenzeni kwe-ferrite ethambileyo kwizicelo zoxinzelelo yingxaki yokungena [1], ehambelana nokuphazamiseka kwengundoqo.Kukho iindlela ezintathu zokusebenzisa i-ferrite njengomcinezeli wemiqondiso engafunekiyo (eyenziweyo okanye ekhutshwe ngemitha. .. Eyokuqala, kwaye incinci iqhelekileyo, njengekhaka elisebenzayo, apho i-ferrites isetyenziselwa ukwahlula abaqhubi, amacandelo okanye iisekethe ezivela kwindawo ejikelezayo ye-electromagnetic field.Kwisicelo sesibini, ii-ferrites zisetyenziselwa izinto ze-capacitive ukudala ukudlula okuphantsi. filter, okt inductance - capacitive at low frequencies and dissipation at high frequencies.Eyesithathu kwaye ixhaphake kakhulu ukusetyenziswa kuxa i-ferrite cores isetyenziswa yodwa kwi-component lead or board-level circuits.Kwesi sicelo, i-ferrite core ithintela nayiphi na i-oscillations ye-parasitic kunye/ okanye attenuates engafunwayo ukuchotshelwa isignali okanye ukuhanjiswa ukuba ukusasaza ecaleni icandelo elikhokelayo okanye uqhagamshelo, umkhondo okanye iintambo. Kwisicelo yesibini neyesithathu, ferrite cores ukucinezela eyenziwa EMI ngokuphelisa okanye ngokunciphisa kakhulu imisinga ephezulu frequency ezitsalwa imithombo EMI.Ukwaziswa ferrite ibonelela Ngokwethiyori, i-ferrite efanelekileyo inokubonelela nge-impedance ephezulu kwi-EMI frequencies kunye ne-zero impedance kuzo zonke ezinye iifrikhwensi. I-impedance ephezulu inokufumaneka phakathi kwe-10 MHz kunye ne-500 MHz ngokuxhomekeke kwizinto ze-ferrite.
Ekubeni ihambelana nemigaqo yobunjineli bombane, apho i-AC voltage kunye ne-current imelwe yiparameters eziyinkimbinkimbi, ukunyanzeliswa kwezinto eziphathekayo kunokubonakaliswa njengepharamitha eyinkimbinkimbi equka iinxalenye zangempela kunye neengcamango. Ukwazi ukungena kucandeke kumacandelo amabini.Eyona ndawo isebenzayo (μ') imele indawo esebenzayo, ekwisigaba kunye nendawo enemagnethi etshintshanayo [2], ngelixa indawo yentelekelelo (μ”) imele iilahleko, eziphume kwinqanaba indawo yemagnethi etshintshanayo.Ezi zinokuchazwa njengeenxalenye zoluhlu (μs'μs”) okanye kwicandelo elinxuseneyo (µp'µp”).Iigrafu kwiMizobo 1, 2, kunye ne-3 ibonisa amacandelo amacandelo obunzima bokuqala bokugqithiswa njengomsebenzi wokuphindaphinda kwizinto ezintathu ze-ferrite.Uhlobo lwezinto eziphathekayo 73 yi-ferrite ye-manganese-zinc, i-magnetic yokuqala I-conductivity yi-2500. Uhlobo lwe-Material 43 yi-nickel zinc ferrite kunye ne-permeability yokuqala ye-850. Uhlobo lwezinto eziphathekayo 61 yi-nickel zinc ferrite ene-permeability yokuqala ye-125.
Ugxininiso lwecandelo loluhlu lwezinto eziphathekayo kwi-Figure 3, sibona ukuba inxalenye yokwenyani yokungena, i-μs ', ihlala ihleli ngokunyuka kwamaxesha kuze kube yilapho i-frequency ebalulekileyo ifikelelwe, kwaye iyancipha ngokukhawuleza.Ilahleko okanye i-μs" iphakama. kwaye ke iphakame njenge μs' falls.Oku kuncipha kwi-μs kungenxa yokuqalisa kweresonance ye-ferrimagnetic.[3] Kufuneka kuqatshelwe ukuba okukhona kuphezulu ukunyanzeliswa, kokukhona kusezantsi i-frequency.Obu budlelwane buchasayo baqale bajongwa nguSnoek kwaye banika le fomula ilandelayo:
apho: ƒres = μs” ukuphindaphindeka kobuninzi γ = umlinganiselo we-gyromagnetic = 0.22 x 106 A-1 m μi = ukungeneka kokuqala uMsat = 250-350 Am-1
Ekubeni i-ferrite cores esetyenziswa kwinqanaba eliphantsi lomqondiso kunye nezicelo zamandla zigxininisa kwiiparamitha zemagneti ezingaphantsi kwesi sihlandlo, abavelisi be-ferrite abafane bapapashe ukufikeleleka kunye / okanye ilahleko yedatha kwi-frequencies.
Uphawu ukuba uninzi lwabavelisi be-ferrite luchaza amacandelo asetyenziselwa ukunyanzeliswa kwe-EMI yi-impedance.Impedance ilinganiswa lula kwi-analyzer ekhoyo ngokurhweba kunye ne-digital readout ngqo.Ngelishwa, i-impedance idla ngokuchazwa kwi-frequency ethile kwaye i-scalar emele ubukhulu be-complex. I-impedance vector.Nangona olu lwazi luxabisekile, luhlala lungonelanga, ngakumbi xa lubonisa ukusebenza kwesekethe ye-ferrites.Ukufezekisa oku, ixabiso le-impedance kunye ne-angle yesigaba secandelo, okanye ukunyanzeliswa okuyinkimbinkimbi kwezinto ezithile, kufuneka kubekho.
Kodwa nangaphambi kokuba uqalise ukwenza imodeli yokusebenza kwamacandelo e-ferrite kwisekethe, abaqulunqi kufuneka bazi oku kulandelayo:
apho μ'= indawo yokwenyani yokungeneka okuntsokothileyo μ”= inxalenye yentelekelelo yokungeneka okuntsokothileyo j = i-vector yentelekelelo yeyunithi Lo= inductance engundoqo womoya
I-impedance ye-iron core nayo ithathwa njengoluhlu lwendibaniselwano ye-inductive reactance (XL) kunye nokumelana nokulahlekelwa (Rs), zombini ezixhomekeke rhoqo.
apho: I-Rs = ukuxhathisa uchungechunge olupheleleyo = Rm + Re Rm = ukuxhathisa uchungechunge olulinganayo ngenxa yelahleko yemagnethi
Kwii-frequencies eziphantsi, i-impedance yecandelo ngokuyinhloko i-inductive.Njengoko i-frequency inyuka, i-inductance iyancipha ngelixa ilahleko inyuka kwaye i-impedance iyonke iyanda.Umzobo we-4 uyisicwangciso esiqhelekileyo se-XL, i-Rs kunye ne-Z ngokuphikisana nokuphindaphinda kwezinto zethu eziphakathi. .
Ke i-reactance inductive ilingana neyona ndawo yokwenyani yokwazi ukutyhutyha, nguLo, i-air-core inductance:
Ukuchasana kwelahleko kukwalingana nenxalenye yentelekelelo yobunzima obungagungqiyo ngokuguquguquka okufanayo:
Kwi-Equation 9, undoqo wemathiriyeli unikwa ngo-µs' kunye noµs”, kwaye ijometri engundoqo inikwa nguLo. Ngoko ke, emva kokwazi ukutyhutyha okuntsonkothileyo kweeferrites ezahlukeneyo, uthelekiso lunokwenziwa ukuze kufunyanwe eyona mathiriyeli ifanelekileyo kwezona zifunwayo. Emva kokukhetha ezona zinto zilungileyo, lixesha lokukhetha ezona nxalenye zilungileyo zobungakanani.Ukumelwa kweVector ye-complex permeability kunye ne-impedance iboniswe kuMfanekiso 5.
Ukuthelekiswa kweemilo ezingundoqo kunye nezixhobo ezingundoqo zokuphucula i-impedance zichanekile ukuba umenzi ubonelela ngegrafu ye-permeability enzima ngokuchasene nokuphindaphinda kwezinto ze-ferrite ezicetyiswayo kwizicelo zoxinzelelo.Ngelishwa, olu lwazi alufumaneki. curves.Ukusuka kule datha ukuthelekiswa kwezinto ezisetyenziselwa ukunyusa i-impedance engundoqo inokufumaneka.
Ngokubhekiselele kuMzobo we-6, ukunyanzeliswa kokuqala kunye ne-disipation factor [4] ye-Fair-Rite 73 imathiriyeli ngokubhekiselele kwi-frequency, kucingelwa ukuba umyili ufuna ukuqinisekisa ukhuseleko oluphezulu phakathi kwe-100 kunye ne-900 kHz.73 izinto ezikhethiweyo. Ngeenjongo zemodeli, umyili naye idinga ukuqonda iindawo ezisebenzayo kunye nezixhathisayo ze-impedance vector kwi-100 kHz (105 Hz) kunye ne-900 kHz. Olu lwazi lunokufumaneka kwitshathi elandelayo:
Kwi-100kHz μs ' = μi = 2500 kwaye (Tan δ / μi) = 7 x 10-6 kuba u-Tan δ = μs ”/ μs' ngoko μs” = (Tan δ / μi) x (μi) 2 = 43.8
Kufuneka kuqatshelwe ukuba, njengoko kulindelekile, i-μ” yongeza kancinane kakhulu kwivektha yokwazi ukutyhubela kweli xesha liphantsi.I-impedance ye-core ininzi inductive.
Abaqulunqi bayazi ukuba i-core kufuneka yamkele i- #22 wire kwaye ingene kwisithuba se-10 mm x 5 mm. I-diameter yangaphakathi iya kuchazwa njenge-0.8 mm. Ukusombulula i-impedance eqikelelweyo kunye namacandelo ayo, khetha kuqala i-bead ene-diameter yangaphandle 10 mm kunye nobude be-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 kwi-100 kHz
Kule meko, njengakwimeko ezininzi, ukungabikho kokuphezulu kuphunyezwa ngokusebenzisa i-OD encinci enobude obude.Ukuba i-ID inkulu, umz.
Indlela efanayo ingasetyenziswa ukuba iiplani ze-impedance kwiyunithi nganye ye-Lo kunye ne-angle ye-angle echasene ne-frequency inikezelwa.Amanani 9, 10 kunye ne-11 amele iigophe ezinjalo kwizinto ezintathu ezifanayo ezisetyenziswe apha.
Abaqulunqi bafuna ukuqinisekisa ukungasebenzi kakuhle kwi-25 MHz ukuya kwi-100 MHz uluhlu lwamaza. okanye uMfanekiso 8 wokungena kobunzima bezinto ezintathu ezifanayo, khetha i-850 μi imathiriyeli.Ukusebenzisa igrafu kuMzobo we-9, i-Z/Lo yezinto ezifikelelekayo eziphakathi yi-350 x 108 ohm/H kwi-25 MHz.Sombulula i-impedance eqikelelweyo:
Ingxoxo eyandulelayo ithatha ukuba undoqo wokukhetha yi-cylindrical.Ukuba i-ferrite cores isetyenziselwa iintambo zeribhoni ezisicaba, iintambo ezidityanisiweyo, okanye iipleyiti ezinemingxuma, ukubala kweLo kuba nzima ngakumbi, kwaye ubude bendlela engundoqo ichaneke ngokufanelekileyo kunye namanani ommandla asebenzayo kufuneka afumaneke. ukubala i-air core inductance .Oku kunokwenziwa ngemathematika ukusika undoqo kunye nokongeza ubude bendlela obaliweyo kunye nommandla wemagnethi kwisilayi ngasinye. ubude/ubude bondoqo we-ferrite.[6]
Njengoko kukhankanyiwe, uninzi lwabavelisi luchaza ii-cores ze-EMI applications ngokwemiqathango ye-impedance, kodwa umsebenzisi wokugqibela ufuna ukwazi i-attenuation.Ubudlelwane obukhoyo phakathi kwezi parameters zimbini:
Olu dlelwane luxhomekeke ekuthinteleni komthombo ovelisa ingxolo kunye nokuphazamiseka komthwalo ofumana ingxolo.La maxabiso adla ngokuba ngamanani antsonkothileyo, anoluhlu olungenasiphelo, kwaye alufumaneki lula kumyili.Ukukhetha ixabiso le I-1 ohm yokuphazamiseka komthwalo kunye nomthombo, onokuthi kwenzeke xa umthombo yimowudi yokutshintshela unikezelo lwamandla kunye nomthwalo wemijikelezo emininzi ephantsi ye-impedance, yenza lula i-equations kwaye ivumela ukuthelekisa ukuthotywa kwee-cores ze-ferrite.
Igrafu ekuMzobo we-12 yiseti yeegophe ezibonisa ubudlelwane phakathi kwe-shield bead impedance kunye nokunciphisa amaxabiso amaninzi aqhelekileyo omthwalo kunye ne-impedance ye-generator.
Umzobo we-13 yisekethe elinganayo yomthombo wokuphazamiseka kunye nokuchasana kwangaphakathi kwe-Zs.Isibonakaliso sokuphazamiseka senziwa yi-series impedance Zsc ye-core suppressor core kunye ne-impedance yomthwalo we-ZL.
Amanani 14 kunye ne-15 iigrafu ze-impedance ngokubhekiselele kwiqondo lokushisa kwizinto ezintathu ezifanayo ze-ferrite.Ezona zinto zizinzileyo kwezi zixhobo ziyizinto ze-61 kunye nokunciphisa i-8% kwi-impedance kwi-100º C kunye ne-100 MHz.Ngokwahlukileyo, izinto ze-43 zibonise i-25 I-% yehla kwi-impedance kwi-frequency kunye nobushushu obufanayo.La magophe, xa ebonelelwe, angasetyenziselwa ukulungelelanisa i-impedance yeqondo lokushisa elichaziweyo ukuba ukuthotywa kwamaqondo okushisa aphezulu kuyafuneka.
Njengeqondo lobushushu, i-DC kunye ne-50 okanye i-60 Hz yonikezelo lwemisinga iphinda ichaphazele iipropati ezifanayo ze-ferrite, ezibangela ukuba i-impedance ephantsi. .Le ngqungquthela ichaza ukuthotywa kwe-impedance njengomsebenzi wamandla entsimi kwisixhobo esithile njengomsebenzi we-frequency.Kufuneka kuqatshelwe ukuba umphumo we-bias uyancipha njengoko ukunyuka kwenyuka.
Ekubeni le datha ihlanganiswe, i-Fair-Rite Products iye yazisa izinto ezimbini ezintsha.I-44 yethu yinto ye-nickel-zinc medium permeability material kunye ne-31 yethu yinto ephezulu ye-manganese-zinc.
Umzobo we-19 yiplani ye-impedance ngokubhekiselele kwi-frequency ye-beads yobukhulu obufanayo kwi-31, i-73, i-44 kunye ne-43 izinto eziphathekayo. Izinto ze-44 ziyizinto eziphuculweyo ze-43 kunye ne-DC resistivity ephezulu, i-109 ohm cm, iipropati ezingcono zokutshatyalaliswa kwe-thermal, ukuzinza kweqondo lokushisa kunye ubushushu obuphezulu beCurie (Tc). Izinto ezingama-44 zineimpedance ephezulu kancinane ngokuchasene neempawu zokuphindaphinda xa kuthelekiswa nezinto zethu ezingama-43. Izinto ezimileyo 31 zibonisa ukhubazeko oluphezulu kunoma 43 okanye 44 kulo lonke uluhlu lwamaza okulinganisa. I-31 yenzelwe ukunciphisa ingxaki yedimensional resonance echaphazela ukusebenza okuphantsi kocinezelo lwezinki ezinkulu ze manganese-zinc cores kwaye isetyenziswe ngempumelelo kwiicores zentambo yesiqhagamshelo kunye neecores ezinkulu ze-toroidal.Umzobo wama-20 licebo le-impedance ngokuchasene nokuphindaphinda kwe-43, 31, kunye ne-73 yezixhobo zeFair. -Rite cores kunye ne-0.562 ″ OD, i-ID ye-0.250, kunye ne-1.125 HT.Xa uthelekisa i-Figure 19 kunye ne-Figure 20, kufuneka kuqatshelwe ukuba kwii-cores ezincinci, kwii-frequencies ukuya kwi-25 MHz, i-73 impahla iyona nto ibhetele yokucinezela.Nangona kunjalo, njengoko i-core cross section inyuka, i-frequency ephezulu iyancipha.Njengoko kuboniswe kwidatha kwi-Figure 20, i-73 iyona nto ingcono I-frequency ephezulu yi-8 MHz.Kuyafaneleka ukuba uqaphele ukuba izinto ezingama-31 ziqhuba kakuhle kuluhlu lwamaza ukusuka kwi-8 MHz ukuya kwi-300 MHz.Nangona kunjalo, njenge-zinc ferrite ye-manganese, izinto ezingama-31 zinevolumu ephantsi kakhulu ye-resistiveivity ye-102 ohms -cm, kunye nokutshintsha kwe-impedance ngakumbi ngotshintsho olugqithisileyo lobushushu.
Iglosari Air Core Inductance - Lo (H) I-inductance eya kulinganiswa ukuba ingundoqo ine-uniform permeability kunye nokuhanjiswa kwe-flux kuhlala kuhleli.Ifomula ngokubanzi Lo= 4π N2 10-9 (H) C1 Ring Lo = .0461 N2 log10 (OD /ID) Ht 10-8 (H) Imilinganiselo ikwi-mm
I-Attenuation - A (dB) Ukunciphisa i-amplitude yesignali ekuhanjisweni ukusuka kwelinye iphuzu ukuya kwelinye.Kungumlinganiselo we-scalar we-input amplitude kwi-output amplitude, kwi-decibels.
I-Core Constant - C1 (cm-1) Isixa sobude bendlela yamagnetic yecandelo ngalinye le-magnetic circuit eyahlulwe ngummandla ohambelana nemagnethi yecandelo elifanayo.
I-Core Constant - C2 (cm-3) Isixa sobude beesekethe zemagnethi zecandelo ngalinye le-magnetic circuit eyahlulwe ngesikwere se-domain magnetic ehambelanayo yecandelo elifanayo.
Imilinganiselo esebenzayo yendawo yemagnethi ye-Ae (cm2), ubude bendlela le (cm) kunye nomthamo we-Ve (cm3) Kwijometri engundoqo enikiweyo, kucingelwa ukuba ubude bendlela yemagnethi, indawo enqamlezayo, kunye nomthamo we undoqo we-toroidal uneempawu zezinto ezifanayo njengezinto eziphathekayo kufuneka zibe neempawu zamagnetic ezilingana nengundoqo enikeziweyo.
Amandla ommandla – H (Oersted) Iparamitha ebonisa ubukhulu bamandla entsimi.H = .4 π NI/le (Oersted)
Uxinaniso lwe-Flux – B (Gaussian) Ipharamitha ehambelanayo yendawo yamagnetic eyenziweyo kummandla oqhelekileyo kwindlela yokuguquguquka.
I-Impedance – Z (ohm) I-impedance ye-ferrite inokubonakaliswa ngokobunzima bayo bokungena.Z = jωLs + Rs = jωLo(μs'- jμs”) (ohm)
I-Loss Tangent – ​​tan δ Ilahleko ye-tangent ye-ferrite ilingana ne-reciprocal yesekethe Q.
I-Loss Factor – tan δ/μi Ukususwa kwesigaba phakathi kwamalungu angundoqo oxinaniso lwemagnethi eguquguqukayo kunye nokomelela kwebala kunye nokungeneka kokuqala.
IMagnetic Permeability – μ Ukufikeleleka kwemagnethi okuvela kumlinganiselo woxinaniso lwemagnethi eguquguqukayo kunye namandla omhlaba atshintshanayo asetyenziswayo kuku...
I-Amplitude permeability, μa – xa ixabiso elikhankanyiweyo loxinaniso lokuhamba likhulu kunexabiso elisetyenziselwa ukungeneka kokuqala.
Ukufikeleleka okusebenzayo, μe – Xa umzila kazibuthe wakhiwe ngesithuba somoya esinye okanye ngaphezulu, ukufikeleleka kukufikeleleka kwemathiriyeli eqikelelwayo enokuthi inike ukungafuni okufanayo.
Ukuthobela ngowona mthombo weendaba, ulwazi, imfundo kunye nenkuthazo yeengcali zobunjineli bombane neze-elektroniki.
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