Hloov hom fais fab mov EMI tsim kev paub
1. EMI qhov chaw hloov hluav taws xob
EMI cuam tshuam los ntawm kev hloov cov khoom siv hluav taws xob yog tsom rau hauv cov hluav taws xob hloov hluav taws xob, cov khoom siv hluav taws xob, cov hluav taws xob hloov hluav taws xob, thiab lwm yam. Qhov chaw sab nraud cuam tshuam rau kev hloov cov khoom siv hluav taws xob feem ntau yog los ntawm lub zog ntawm daim phiaj hluav taws xob, hluav taws xob tawm tsam, hluav taws xob sab nraud, thiab lwm yam.
(1) Fais fab hloov raj
Lub hwj chim hloov raj ua haujlwm nyob rau hauv lub xeev ntawm On-Off ceev lub voj voog hloov pauv, thiab ob qho tib si dv / dt thiab di / dt hloov pauv sai. Yog li ntawd, lub hwj chim hloov raj tsis yog tsuas yog lub ntsiab cuam tshuam ntawm hluav taws xob teb coupling, tab sis kuj yog lub ntsiab cuam tshuam qhov chaw ntawm magnetic teb coupling.
(2) High zaus transformer
Lub EMI qhov chaw ntawm high-frequency transformers yog concentrated nyob rau hauv lub ceev cyclic transformation ntawm di / dt sib xws rau to to inductance. Yog li ntawd, high-frequency transformers yog ib qho tseem ceeb cuam tshuam qhov chaw ntawm magnetic teb coupling.
(3) Rectifier diode
EMI qhov chaw ntawm lub rectifier diode yog concentrated nyob rau hauv cov yam ntxwv rov qab. Lub discontinuity point ntawm qhov rov qab rov qab tam sim no yuav ua rau siab dv / dt nyob rau hauv inductance (lead inductance, stray inductance, thiab lwm yam), ua rau muaj zog electromagnetic cuam tshuam.
(4) PCB
Kom meej meej, PCB yog qhov txuas txuas rau cov kev cuam tshuam saum toj no. Qhov zoo ntawm PCB ncaj qha cuam tshuam rau kev tawm tsam ntawm EMI qhov chaw saum toj no.
2. Kev faib hluav taws xob hloov hluav taws xob EMI kis tau tus mob
(1) Transmission channel rau conductive cuam tshuam
(1) Capacitive coupling
(2) Inductive coupling
(3) Resistive coupling
ib. Resistive conduction coupling tshwm sim los ntawm lub internal tsis kam ntawm pej xeem fais fab mov
b. Resistive conduction coupling tshwm sim los ntawm impedance ntawm cov kab hauv av
c. Resistive conduction coupling tshwm sim los ntawm kab impedance
(2) Kev sib kis ntawm cov hluav taws xob cuam tshuam
(1) Hauv kev hloov cov khoom siv hluav taws xob, cov khoom siv thiab cov xaim hluav taws xob uas tuaj yeem tsim cov hluav taws xob cuam tshuam tuaj yeem suav tias yog cov kav hlau txais xov, thiab cov hluav taws xob dipole thiab magnetic dipole theories tuaj yeem siv rau kev tsom xam; diodes, capacitors, thiab fais fab hloov raj tuaj yeem suav tias yog Hluav Taws Xob dipole, inductor coil tuaj yeem suav tias yog magnetic dipole;
(2) Thaum tsis muaj kev tiv thaiv lub cev, lub electromagnetic yoj kis tau tus mob channel generated los ntawm hluav taws xob dipoles thiab magnetic dipoles yog huab cua (tuaj yeem xav tias yog qhov chaw dawb);
(3) Thaum muaj cov ntaub thaiv npog, xav txog qhov khoob thiab qhov nyob hauv daim ntaub thaiv thiab txheeb xyuas thiab ua raws li tus qauv lej ntawm qhov xau.
3. 9 cov kev ntsuas loj los txwv EMI hauv kev hloov cov khoom siv hluav taws xob
Hauv kev hloov cov khoom siv hluav taws xob, kev hloov pauv tam sim ntawm qhov hluav taws xob thiab tam sim no, uas yog, siab dv / dt thiab di / dt, yog lub ntsiab ua rau EMI. Kev ntsuas kev siv EMC tsim ntawm kev hloov hluav taws xob yog feem ntau raws li ob lub ntsiab lus hauv qab no:
(1) Txo cov kev cuam tshuam los ntawm cov khoom siv hluav taws xob nws tus kheej, siv cov kev cuam tshuam cuam tshuam los yog tsim cov khoom siv thiab cov khoom siv hluav taws xob tsawg, thiab ua cov txheej txheem tsim nyog;
(2) Tshem tawm EMI ntawm cov khoom siv hluav taws xob thiab txhim kho EMS ntawm cov khoom siv hluav taws xob los ntawm kev siv hauv av, lim, thaiv thiab lwm yam thev naus laus zis.
Hais lus sib cais, cuaj qhov kev ntsuas loj yog:
(1) Txo dv / dt thiab di / dt (txo lawv cov nqi siab tshaj thiab ua kom lawv txoj kab nqes)
(2) Tsim nyog thov ntawm varistor kom txo qhov hluav taws xob surge
(3) Damping network suppresses overshoot
(4) Siv diodes nrog cov yam ntxwv zoo rov qab los txo qis EMI zaus
(5) Kev kho lub zog muaj zog thiab lwm yam kev kho kom haum xeeb
(6) Siv lub tshuab lim hluav taws xob tsim kom zoo
(7) Kev kho av tsim nyog
(8) Kev tiv thaiv kev tiv thaiv zoo
(9) Tsim nyog PCB tsim
