Generation Mechanisms thiab Suppression Technologies of Electromagnetic Interference in Switching Power Supplies
Kev Tiv Thaiv ntawm Electromagnetic cuam tshuam hauv Switching Power Supply
Peb lub ntsiab lus uas tsim electromagnetic cuam tshuam yog qhov cuam tshuam, kev nthuav dav, thiab cov khoom cuam tshuam. Yog li, kev cuam tshuam electromagnetic cuam tshuam yuav tsum tau hais los ntawm peb yam no. Lub hom phiaj yog txhawm rau txhawm rau cuam tshuam cov peev txheej, tshem tawm kev sib txuas thiab hluav taws xob ntawm cov khoom cuam tshuam thiab cov khoom siv cuam tshuam, thiab txhim kho kev tiv thaiv - cuam tshuam muaj peev xwm ntawm cov khoom cuam tshuam, yog li txhim kho cov khoom siv hluav taws xob sib xyaw ua ke ntawm kev hloov cov khoom siv hluav taws xob.
Siv cov ntxaij lim dej los tiv thaiv kev cuam tshuam electromagnetic
Kev lim dej yog ib txoj hauv kev tseem ceeb rau kev tiv thaiv kev cuam tshuam ntawm electromagnetic cuam tshuam, uas tuaj yeem cuam tshuam qhov nkag ntawm electromagnetic cuam tshuam rau hauv cov khoom siv hauv daim phiaj hluav taws xob, thiab tseem txwv tsis pub nkag ntawm electromagnetic cuam tshuam los ntawm cov khoom siv rau hauv daim phiaj hluav taws xob. Txhim kho lub zog hloov hluav taws xob hauv cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob ntawm cov khoom siv hluav taws xob hloov tsis tau tsuas yog daws qhov teeb meem ntawm kev cuam tshuam, tab sis kuj tseem ua lub luag haujlwm tseem ceeb hauv kev hais txog kev cuam tshuam hluav taws xob. Lub tshuab lim lim tau muab faib ua ob txoj hauv kev: passive filtering thiab nquag lim.
Passive filtering tshuab
Passive filtering circuits yog qhov yooj yim, tus nqi - ua tau zoo, thiab txhim khu kev qha, ua rau lawv muaj txiaj ntsig zoo los cuam tshuam electromagnetic cuam tshuam. Cov lim dej Passive yog tsim los ntawm inductive, capacitive, thiab resistive ntsiab, thiab lawv txoj haujlwm ncaj qha yog los daws qhov teeb meem ntawm conduction emission.
Daim duab schematic ntawm passive lim siv nyob rau hauv hloov hom fais fab mov yog qhia nyob rau hauv daim duab 1.
Vim lub peev xwm loj ntawm lub lim dej capacitor nyob rau hauv thawj lub hwj huam mov Circuit Court, mem tes ncov tam sim no yog tsim nyob rau hauv lub rectification Circuit Court, uas yog tsim los ntawm ntau yam siab - txiav txim harmonic tam sim no thiab cuam tshuam rau hauv daim phiaj fais fab; Tsis tas li ntawd, qhov kev sib txuas los yog kev txiav tawm ntawm lub raj hloov pauv hauv Circuit Court thiab lub hauv paus kauj ntawm lub transformer yuav tsim cov pulsating tam sim no. Vim tias qhov kev hloov pauv tam sim no siab, induced tam sim no ntawm cov zaus sib txawv yog tsim nyob rau hauv ib puag ncig circuits, nrog rau kev sib txawv thiab hom kev cuam tshuam cov teeb liab. Cov teeb liab cuam tshuam no tuaj yeem ua rau lwm cov kab hauv kab hluav taws xob thiab cuam tshuam nrog lwm cov khoom siv hluav taws xob los ntawm ob txoj kab hluav taws xob. Qhov sib txawv hom kev lim dej hauv daim duab tuaj yeem txo qhov sib txawv ntawm qhov cuam tshuam cov teeb liab hauv cov khoom siv hluav taws xob hloov, thiab ua rau lub zog hluav taws xob cuam tshuam los ntawm cov khoom siv nws tus kheej thaum lub sijhawm ua haujlwm thiab xa mus rau hauv daim phiaj hluav taws xob. Raws li txoj cai ntawm electromagnetic induction, E=Ldi/dt, qhov twg E yog qhov voltage poob thoob L; L yog inductance; Di/dt yog tus nqi hloov pauv tam sim no. Pom tseeb, qhov me dua qhov hloov pauv tam sim no xav tau, qhov loj dua qhov xav tau inductance.
Lub teeb liab cuam tshuam tsim los ntawm cov mem tes tam sim no Circuit Court los ntawm electromagnetic induction nrog rau lwm cov circuits thiab Circuit Court tsim los ntawm lub ntiaj teb los yog casing yog ib hom teeb liab; Nyob rau hauv lub switching fais fab mov Circuit Court, ib tug muaj zog hluav taws xob teb yog generated ntawm lub collector ntawm switching transistor thiab lwm yam circuits, thiab lub Circuit Court yuav tsim tawm tam sim no, uas kuj belongs rau cov hom kev cuam tshuam cov teeb liab. Daim duab 1 * Hom lim yog siv los tiv thaiv hom kev cuam tshuam thiab ua rau nws txo qis.
