Kev cuam tshuam thiab kev tawm tsam ntawm kev hloov hluav taws xob
Kev cuam tshuam los ntawm kev hloov hluav taws xob hloov pauv nws tus kheej ncaj qha cuam tshuam rau kev ua haujlwm ntawm cov khoom siv hluav taws xob. Tiv thaiv lub suab nrov ntawm lub tshuab hluav taws xob hluav taws xob hloov hluav taws xob nws tus kheej yog lub ntsiab lus tseem ceeb hauv kev txhim kho thiab tsim cov khoom siv hluav taws xob hloov. Tsab ntawv xov xwm no luv luv qhia txog cov txheej txheem ntawm kev cuam tshuam ntawm electromagnetic cuam tshuam thiab kev nthuav tawm hauv kev hloov cov khoom siv hluav taws xob, thiab qhia txog ntau txoj hauv kev rau kev tawm tsam tiam thiab kev nthuav tawm ntawm electromagnetic cuam tshuam hauv kev hloov cov khoom siv hluav taws xob.
Hloov cov khoom siv hluav taws xob, ua cov khoom siv hluav taws xob rau cov khoom siv hluav taws xob, muaj qhov zoo ntawm qhov me me, lub teeb yuag, thiab kev ua haujlwm siab, thiab tau siv dav hauv digital circuits. Txawm li cas los xij, vim nws lub xeev hloov pauv siab, nws yog qhov muaj zog cuam tshuam, thiab qhov cuam tshuam los ntawm nws ncaj qha cuam tshuam rau kev ua haujlwm ntawm cov khoom siv hluav taws xob. Yog li ntawd, suppressing lub suab nrov ntawm lub tshuab hluav taws xob hloov hluav taws xob nws tus kheej thiab txhim kho nws txoj kev tiv thaiv electromagnetic cuam tshuam los xyuas kom meej lub sijhawm ntev kev nyab xeeb thiab txhim khu kev qha ntawm cov khoom siv hluav taws xob yog lub ntsiab lus tseem ceeb hauv kev txhim kho thiab tsim cov khoom siv hluav taws xob hloov.
Generation of Switching Power Supply Interference
Kev cuam tshuam ntawm kev hloov cov khoom siv hluav taws xob feem ntau yog muab faib ua ob pawg: thawj zaug, kev cuam tshuam los ntawm cov khoom siv sab hauv ntawm cov khoom siv hluav taws xob hloov; Qhov thib ob yog qhov cuam tshuam los ntawm lwm yam hauv lub zog hloov hluav taws xob. Ob leeg koom nrog tib neeg thiab tej yam ntuj tso.
Internal cuam tshuam ntawm switching fais fab mov
Lub EMI tsim los ntawm kev hloov cov khoom siv hluav taws xob feem ntau yog tshwm sim los ntawm qhov kev txiav txim siab sib haum xeeb tam sim no cuam tshuam los ntawm cov txheej txheem rectifier thiab lub ncov voltage cuam tshuam los ntawm lub zog hloov hluav taws xob.
Basic rectifier
Cov txheej txheem rectification ntawm ib qho yooj yim rectifier yog feem ntau ua rau EMI. Qhov no yog vim hais tias lub hwj chim zaus AC sine yoj tsis yog ib zaus tam sim no tom qab kho, tab sis dhau los ua DC tivthaiv thiab cov khoom sib txuam nrog ntau zaus. Harmonics (tshwj xeeb tshaj yog kev txiav txim siab dua kev sib haum xeeb) yuav tsim kev cuam tshuam kev cuam tshuam thiab hluav taws xob cuam tshuam raws cov kab sib kis, ua rau muaj kev cuam tshuam ntawm lub hauv ntej-kawg tam sim no. Ntawm qhov tod tes, nws yuav ua rau muaj kev cuam tshuam ntawm cov waveform tam sim no txuas nrog nws cov kab hluav taws xob pem hauv ntej, thiab ntawm qhov tod tes, nws yuav tsim cov xov tooj cua zaus cuam tshuam los ntawm cov kab hluav taws xob.
Fais fab conversion Circuit Court
Lub zog hloov hluav taws xob hloov hluav taws xob yog qhov tseem ceeb ntawm kev hloov hluav taws xob tswj hluav taws xob, uas ua rau muaj qhov dav bandwidth thiab nplua nuj harmonics. Cov khoom tseem ceeb uas ua kom muaj kev cuam tshuam ntawm cov mem tes no yog
1) Muaj kev faib tawm ntawm lub raj hloov pauv thiab nws lub dab dej kub, lub plhaub, thiab cov coj hauv lub zog. Thaum lub raj hloov pauv ntws los ntawm cov mem tes loj tam sim no (feem ntau yog ib lub voj voos), lub waveform muaj ntau cov khoom siv ntau zaus; Nyob rau tib lub sijhawm, cov khoom siv tsis siv los tua hluav taws xob, xws li lub sijhawm khaws cia ntawm lub zog hloov hluav taws xob, qhov loj tam sim no ntawm cov zis theem, thiab lub sijhawm rov qab los ntawm kev hloov pauv rectifier diode, tuaj yeem ua rau lub sijhawm tam sim no. luv luv Circuit Court, tsim ib tug loj luv luv-circuit tam sim no. Tsis tas li ntawd, kev thauj khoom ntawm lub raj hloov pauv yog lub tshuab hluav taws xob ntau zaus lossis lub zog cia inductor. Thaum lub sij hawm ntawm lub hloov raj conduction, muaj ib tug loj inrush tam sim no nyob rau hauv lub transformer thawj, ua rau lub ncov nrov.
2) Lub transformer nyob rau hauv ib tug high-frequency transformer switching fais fab mov yog siv rau kev rho tawm thiab voltage transformation, tab sis vim to inductance, electromagnetic induction suab nrov yuav generated; Nyob rau tib lub sij hawm, nyob rau hauv high-frequency tej yam kev mob, kev faib capacitance ntawm cov khaubncaws sab nraud povtseg ntawm lub transformer yuav xa high-order harmonic suab nrov los ntawm thawj sab mus rau theem nrab, thaum lub faib capacitance ntawm lub transformer mus rau lub plhaub ua lwm yam high-zoo. txoj kev zaus, ua kom yooj yim rau cov electromagnetic teb generated nyob ib ncig ntawm lub transformer rau ob peb thiab ua suab nrov ntawm lwm cov leads.
3) Thaum lub thib ob sab rectifier diode ntawm lub rectifier diode yog siv rau high-frequency rectification, vim yog lub sij hawm rov qab los, tus nqi uas muaj nyob rau hauv pem hauv ntej tam sim no tsis tuaj yeem raug tshem tawm tam sim ntawd thaum rov qab voltage siv (vim yog muaj cov cab kuj thiab tam sim no ntws). Thaum txoj kab nqes ntawm qhov rov qab tam sim no loj dhau lawm, qhov inductance ntws los ntawm lub kauj tsim hluav taws xob siab tshaj plaws, uas yuav ua rau muaj kev cuam tshuam ntau zaus nyob rau hauv kev cuam tshuam ntawm transformer to inductance thiab lwm yam kev faib tawm, nrog rau ntau zaus mus txog kaum. ntawm MHz.
4) Capacitors, inductors, thiab xaim hloov pauv cov khoom siv hluav taws xob tuaj yeem ua rau muaj kev hloov pauv ntawm cov yam ntxwv ntawm cov khoom siv tsawg zaus vim lawv ua haujlwm ntawm ntau zaus, ua rau muaj suab nrov.
