Kev siv cov hlaws sib nqus hauv kev hloov hluav taws xob EMC tsim
1 Ferrite EMI Kev Tiv Thaiv Element
Ferrite yog ferrous magnetic khoom nrog lub cubic lattice qauv. Nws cov txheej txheem tsim khoom thiab cov khoom siv kho tshuab zoo ib yam li ceramics, xim yog grey-dub. EMI cov ntxaij lim dej feem ntau siv hauv chav kawm ntawm cov tub ntxhais sib nqus yog cov khoom siv ferrite, ntau lub tuam txhab muab cov khoom siv ferrite tshwj xeeb rau EMI kev tawm tsam. Cov khoom no yog tus cwj pwm los ntawm kev poob loj heev. Rau ferrite rau EMI suppression, qhov tseem ceeb tshaj plaws kev ua tau zoo tsis yog permeability μ thiab saturation flux ceev Bs. Lub permeability μ tuaj yeem qhia tau tias yog tus lej nyuaj, nrog rau qhov tseeb ntawm qhov inductance thiab qhov xav txog qhov sawv cev rau qhov poob, uas nce nrog zaus. Yog li, nws qhov sib npaug Circuit Court yog ib lub voj voog uas muaj cov inductor L thiab resistor R. Ob leeg L thiab R yog cov haujlwm ntawm zaus. Thaum ib lub xaim hla dhau los ntawm cov tub ntxhais ferrite no, qhov tshwm sim inductive impedance ua haujlwm nce raws li zaus
Lub inductive impedance yog tsim los nrog nce zaus, tab sis cov txheej txheem sib txawv ntawm ntau zaus.
Nyob rau hauv lub low-frequency band, impedance los ntawm inductance ntawm inductance, low-frequency R yog heev me me, qhov sib nqus permeability ntawm cov tub ntxhais yog siab, yog li cov inductance loj, L plays lub luag hauj lwm tseem ceeb nyob rau hauv lub electromagnetic cuam tshuam yog reflected. thiab suppressed; thiab lub sij hawm no, qhov poob ntawm cov tub ntxhais yog me me, tag nrho cov cuab yeej yog ib tug tsawg-tsawg, high-Q yam ntxwv ntawm inductance, uas yog nquag resonance, yog li nyob rau hauv lub low-frequency band, tej zaum yuav muaj sij hawm thaum siv. ntawm ferrite hlaws dai tom qab kev cuam tshuam kev txhim kho ntawm qhov tshwm sim.
Nyob rau hauv lub high-frequency band, lub impedance yog tsim los ntawm resistive Cheebtsam, raws li cov zaus nce, lub magnetic permeability ntawm cov tub ntxhais yuav txo, ua rau ib tug txo nyob rau hauv lub inductance ntawm inductor, lub inductive tivthaiv txo, Txawm li cas los, lub sij hawm no, qhov poob. ntawm cov tub ntxhais nce, cov khoom tiv thaiv resistive nce, ua rau muaj kev nce ntxiv hauv tag nrho cov impedance thaum lub siab-frequency signals los ntawm ferrite, electromagnetic cuam tshuam yog absorbed thiab hloov mus rau hauv daim ntawv ntawm thermal zog dissipation.
Ferrite suppression Cheebtsam yog dav siv nyob rau hauv cov ntawv luam Circuit Court boards, fais fab kab thiab cov ntaub ntawv kab. Yog hais tias ib tug ferrite suppression caij ntxiv rau qhov kawg ntawm lub hwj chim kab ntawm lub rooj tsavxwm luam tawm, kev cuam tshuam ntau zaus tuaj yeem lim tawm. Ferrite magnetic nplhaib los yog hlaws tshwj xeeb rau inhibit cov kab teeb liab, cov kab hluav taws xob ntawm kev cuam tshuam ntau zaus thiab kev cuam tshuam loj heev, nws kuj muaj peev xwm nqus tau electrostatic paug pulse cuam tshuam.
2 Lub hauv paus ntsiab lus thiab cov yam ntxwv ntawm cov hlaws hlau nplaum thaum lub sijhawm tam sim no ntws los ntawm nws qhov chaw nruab nrab ntawm cov hlau, nws yuav yog cov hlaws sib nqus sab hauv kev ntws ntawm cov hlau nplaum. Thaum lub ferrite yog tsim los rau EMI tswj, nws yuav tsum tau dissipate feem ntau ntawm cov hlau nplaum flux li cua sov hauv cov khoom. Qhov tshwm sim no tuaj yeem ua qauv los ntawm kev sib xyaw ua ke ntawm inductor thiab resistor. Raws li pom hauv daim duab 2
Tus lej loj ntawm ob lub ntsiab lus yog ncaj qha proportional rau qhov ntev ntawm cov hlaws dai, thiab qhov ntev ntawm cov hlaws dai muaj qhov cuam tshuam loj rau kev tawm tsam, nrog cov hlaws ntev ntev muab kev tiv thaiv zoo dua. Raws li lub teeb liab lub zog yog magnetically txuas rau cov hlaws dai, qhov inductor reactance thiab tsis kam nce nrog zaus. Qhov ua tau zoo ntawm kev sib nqus sib nqus nyob ntawm qhov sib nqus permeability ntawm cov khoom siv hlaws txheeb ze rau huab cua. Kev poob ntawm cov khoom siv ferrite uas ib txwm ua rau cov hlaws tuaj yeem qhia tau tias muaj ntau yam los ntawm nws cov permeability nrog rau huab cua.
Cov khoom siv hlau nplaum feem ntau yog tus cwj pwm los ntawm qhov piv ntawm qhov poob lub kaum sab xis. Lub kaum sab xis loj yog xav tau rau EMI cov khoom tiv thaiv, uas txhais tau hais tias feem ntau ntawm kev cuam tshuam yuav ploj mus.
Qhov no txhais tau tias feem ntau ntawm kev cuam tshuam yuav ploj mus thiab tsis xav txog. Ntau yam ntawm cov ntaub ntawv ferrite muaj niaj hnub no muab cov neeg tsim qauv xaiv ntau cov hlaws siv rau hauv ntau daim ntawv thov.
