Kev daws teeb meem ntawm EMI cuam tshuam rau kev hloov hluav taws xob
Feem ntau hais lus, kev cuam tshuam los ntawm sab nraud hluav taws xob, xob laim tawm tsam, lossis lub zog hluav taws xob jitter, thiab lwm yam rau sab nraud ib puag ncig ntawm cov khoom siv hluav taws xob, xws li rectifier diode, high-frequency transformer, fais fab hloov raj, thiab lwm yam, yog lub ntsiab. Kev tshwm sim ntawm EMI cuam tshuam qhov chaw ntawm kev hloov hluav taws xob.
Ua ntej, kev xa xov hluav taws xob ntawm hluav taws xob cuam tshuam tau qhia.
(1) Hauv kev hloov pauv hluav taws xob, cov khoom siv thiab cov xov hlau uas tuaj yeem tsim hluav taws xob cuam tshuam los ntawm cov kav hlau txais xov, yog li kev tsom xam tuaj yeem tsim los ntawm kev siv txoj kev xav ntawm hluav taws xob dipole thiab magnetic dipole; Diodes, capacitors, hluav taws xob hloov pauv tuaj yeem suav tias yog hluav taws xob dipoles, thiab inductance coils tuaj yeem suav tias yog magnetic dipoles.
(2) Thaum tsis muaj ntaub thaiv npog, lub electromagnetic yoj kis tau tus mob channel tsim los ntawm hluav taws xob dipole thiab magnetic dipole yog huab cua (uas tuaj yeem suav tias yog qhov chaw dawb);
(3) Thaum muaj cov ntaub thaiv npog, xav txog qhov khoob thiab qhov ntawm cov ntaub thaiv npog, cov pa xau tau raug tshuaj xyuas thiab kho raws li tus qauv lej.
Qhov thib ob, nws yog qhov kis tau tus mob channel uas cuam tshuam.
(1) capacitive coupling
(2) Inductive coupling
(3) Resistance coupling
A. tsis kam conduction coupling tshwm sim los ntawm sab hauv tsis kam ntawm pej xeem fais fab mov
B. resistive conductive coupling tshwm sim los ntawm cov av impedance
C. resistive conduction coupling tshwm sim los ntawm kab impedance
Cov phiaj xwm kev tawm tsam hauv qab no muaj feem xyuam nrog EMI cuam tshuam qhov chaw:
1. Shielding ntawm high zaus transformer
Txhawm rau tiv thaiv kom tsis txhob muaj qhov sib nqus ntawm lub tshuab hluav taws xob ntau zaus los ntawm kev cuam tshuam nrog cov kab hluav taws xob nyob ib puag ncig, cov ntaub thaiv npog tuaj yeem siv los tiv thaiv cov xaim hlau nplaum ntawm cov hluav taws xob ntau zaus. Cov ntaub thaiv npog feem ntau yog ua los ntawm cov ntawv ci tooj liab, uas yog qhov txhab ncig sab nraud ntawm lub transformer thiab hauv av. Daim kab xev tiv thaiv yog lub nplhaib luv luv uas cuam tshuam nrog cov xaim hlau nplaum, yog li tiv thaiv cov xau ntawm cov xaim hlau nplaum hauv qhov dav.
Cov txheeb ze hloov chaw yuav tshwm sim ntawm cov cores thiab windings ntawm high-frequency transformer, uas yuav ua rau lub suab nrov (howling thiab vibration) nyob rau hauv lub lag luam ntawm high-frequency transformer. Txhawm rau tiv thaiv cov suab nrov no, nws yog ib qho tsim nyog yuav tsum tau ntsuas qhov ntsuas qhov ntsuas rau lub transformer:
(1) Bonding peb qhov chaw sib nqus ntawm cov cores sib nqus (xws li EE thiab EI cores) nrog epoxy resin txhawm rau txhawm rau cuam tshuam cov txheeb ze;
(2) Nws yog qhov zoo dua los khi cov tub ntxhais sib nqus nrog "iav hlaws" nplaum.
Cais, muaj cuaj ntsuas los txwv EMI hauv kev hloov fais fab mov:
(1) tsim nyog PCB tsim
(2) Tsim nyog thov ntawm varistor kom txo qhov hluav taws xob surge.
(3) Txo dv / dt thiab di / dt (txo nws lub ncov tus nqi thiab qeeb nws txoj kab nqes)
(4) Damping network suppresses overshoot.
(5) Siv lub tshuab lim fais fab uas tsim nyog.
(6) Diodes nrog cov yam ntxwv zoo rov qab yog siv los txo qis EMI zaus.
(7) Kev kho lub zog muaj zog thiab lwm yam kev kho kom haum xeeb.
(8) Kev tiv thaiv kev tiv thaiv zoo
(9) Kev kho av tsim nyog
