Kev soj ntsuam ntawm Electromagnetic Nuisance Sources of High Frequency Switching Power Supplies
Nyob rau hauv lub Circuit Court ntawm lub rectifier, lub hwj chim raj Q1, nyob rau hauv daim duab 1b Circuit Court ntawm lub hwj chim raj Q2 ~ Q5, high-frequency transformer T1, tso zis rectifier diodes D1 ~ D2 yog high-frequency switching fais fab mov ua hauj lwm los tsim electromagnetic harassment ntawm lub ntsiab. qhov chaw ntawm kev thab plaub, kev tsom xam tshwj xeeb yog raws li hauv qab no.
Rectifier rectification txheej txheem tsim kom muaj kev sib haum xeeb nyob rau hauv txoj kab hluav taws xob los ua kom muaj kev cuam tshuam thiab tawg.
Hloov lub hwj chim raj ua haujlwm nyob rau hauv lub xeev ntawm high-frequency conduction thiab txiav-tawm, thiaj li yuav txo tau lub switching poob thiab txhim kho lub zog ceev thiab tag nrho cov efficiency ntawm lub hwj chim mov, lub switching tube tig rau thiab tawm sai thiab sai, feem ntau nyob rau hauv ob peb microseconds, lub switching tube tig rau thiab tawm ntawm xws li ib tug ceev, uas tsim cov inrush voltage thiab inrush tam sim no, thiab nws yuav tsim high-frequency thiab high-voltage spike harmonics, uas yuav tsim electromagnetic cuam tshuam rau qhov chaw thiab lub AC input kab.
Lub high-frequency transformer T1 ua lub zog hloov dua siab tshiab thaum tsim hluav taws xob hloov hluav taws xob uas cuam tshuam cov hluav taws xob hluav taws xob rau hauv qhov chaw, ua rau muaj hluav taws xob tsis zoo. Qhov faib inductance thiab capacitance ntawm lub transformer generates oscillations thiab yog txuas mus rau AC input Circuit Court los ntawm kev faib capacitance nruab nrab ntawm thawj theem ntawm lub transformer, ua ib qho teeb meem.
Nyob rau hauv cov ntaub ntawv ntawm ib tug kuj tsis tshua muaj tso zis voltage, cov zis rectifier diode ua hauj lwm nyob rau hauv ib tug high-frequency switching xeev, uas kuj yog ib qhov chaw ntawm electromagnetic thab plaub.
Vim lub diode tus kab mob parasitic inductance, junction capacitance, thiab cov cuam tshuam ntawm qhov rov qab los tam sim no, yog li nws ua haujlwm ntawm qhov kev hloov pauv ntawm qhov hluav taws xob thiab tam sim no, qhov ntev ntawm diode rov qab lub sij hawm, qhov cuam tshuam ntau dua. spike tam sim no, qhov muaj zog lub teeb liab teeb liab, uas ua rau high-frequency attenuation ntawm oscillations, uas yog ib hom sib txawv-hom ua nuisance.
Tag nrho cov electromagnetic signals generated los ntawm lub hwj chim kab, teeb liab kab, grounding hlau thiab lwm yam hlau xaim xa mus rau sab nraud fais fab mov los tsim ib tug ua tsis taus pa. Cov teeb liab tsis txaus ntseeg tau tawg los ntawm cov xov hlau thiab cov khoom siv lossis los ntawm kev sib txuas ntawm cov xov hlau uas ua raws li cov kav hlau txais xov ua rau muaj kev cuam tshuam tsis zoo.
