Cov yam ntxwv ntawm kev sib txuas lus hloov cov khoom siv hluav taws xob
Nrog rau kev txhim kho cov cuab yeej hluav taws xob niaj hnub thiab cov khoom siv hluav taws xob, cov khoom siv hluav taws xob hloov pauv tau siv dav hauv kev sib txuas lus, kev tswj tsis siv neeg, cov khoom siv hauv tsev thiab lwm yam kev lag luam vim lawv qhov me me, lub teeb yuag, kev ua haujlwm siab, thiab kev ntseeg siab, tshwj xeeb tshaj yog nyob rau hauv cov kev tswj xyuas. Hloov, kho qhov muag cov ntaub ntawv xa mus, wireless hauv paus chaw nres tsheb, cable TV systems thiab IP networks yog lub zog tseem ceeb rau kev ua haujlwm ntawm cov khoom siv thev naus laus zis. Txawm li cas los xij, kev sib txuas lus hloov hluav taws xob feem ntau siv tshuab pulse width modulation (PWM), thiab nws cov khoom siv hloov pauv ua haujlwm hauv lub xeev siab heev. Txij li thaum lub high-frequency ceev transient txheej txheem nws tus kheej yog lub hauv paus ntawm electromagnetic cuam tshuam, lub electromagnetic cuam tshuam (EMI) teeb liab nws generates nws muaj ntau zaus thiab ib tug tej yam amplitude. Nws yuav ua phem rau qhov chaw electromagnetic los ntawm kev siv hluav taws xob thiab hluav taws xob, thiab ua rau muaj kev cuam tshuam rau cov khoom siv sib txuas lus thiab cov khoom siv hluav taws xob. Tsis tas li ntawd, kev sib txuas lus hloov hluav taws xob yuav tsum muaj lub peev xwm tiv thaiv electromagnetic cuam tshuam, tshwj xeeb tshaj yog rau xob laim, surges, daim phiaj hluav taws xob, hluav taws xob, hluav taws xob, hluav taws xob hluav taws xob, hluav taws xob hluav taws xob, hluav taws xob hluav taws xob, tsheb ciav hlau, hluav taws xob poob, xov tooj cua zaus electromagnetic teb. Kev tiv thaiv kev tiv thaiv hluav taws xob, cov khoom hluav taws xob xws li kev tiv thaiv kab mob, kev ua pa tawm, thiab cov hluav taws xob hluav taws xob yuav tsum ua kom tau raws li cov kev cai ntawm EMC cov qauv.
Hauv Suav teb, xyoo 1980 thiab 1990s, txhawm rau txhim kho kev tswj hwm ntawm cov pa phem hauv tsev tam sim no, qee cov qauv tsim raws li cov qauv thoob ntiaj teb xws li CISPR cov qauv thiab IEC801 tau tsim. Txij li Tuam Tshoj Compulsory Certification (ChinaCompulsoryCertification)-K tau siv thaum lub Yim Hli 1, 2003, "EMC kub taub hau" tau raug teeb tsa. Kev tshawb fawb thiab kev tswj hwm ntawm electromagnetic cuam tshuam ntawm qhov sib ze tau nyiam ntau thiab ntau dua los ntawm cov kws tshawb fawb hluav taws xob. Ib qho tshiab hotspot hauv kev tshawb fawb. Daim ntawv no yuav muab kev sib tham txog qhov cuam tshuam txog kev siv thev naus laus zis rau kev tsim cov tshuab hluav taws xob cuam tshuam ntawm kev sib txuas lus hloov hluav taws xob.
1 Cov yam ntxwv ntawm kev sib txuas lus hloov hluav taws xob thiab kev cuam tshuam ntawm electromagnetic cuam tshuam
1.1 Cov yam ntxwv tseem ceeb ntawm kev hloov fais fab mov
Muaj plaub yam tseem ceeb ntawm kev hloov fais fab mov:
①Qhov chaw yog qhov tseeb. Feem ntau tsom rau lub zog hloov khoom siv, diodes, radiators thiab high-frequency transformers txuas nrog lawv;
② Lub zog hloov khoom siv ua haujlwm hauv lub xeev hloov pauv. Vim tias qhov hloov hluav taws xob hloov hluav taws xob yog lub zog hloov hluav taws xob uas ua haujlwm hauv lub xeev hloov pauv, nws qhov hluav taws xob thiab qhov hloov pauv tam sim no siab heev, thiab qhov cuam tshuam kev siv hluav taws xob yog qhov loj;
③ Fais fab luam ntawv Circuit Court board (PCB) thaiv feem ntau yog teem manually. Qhov kev npaj no ua rau nws txawv heev, uas ua rau muaj kev nyuaj siab ntawm kev rho tawm PCB faib tsis tau thiab kwv yees thiab ntsuas kev cuam tshuam ze ntawm thaj chaw;
④ Hloov zaus yog qhov loj, txij li kaum tawm txhiab Hz mus rau ob peb megahertz. Cov ntaub ntawv tseem ceeb ntawm kev cuam tshuam yog kev cuam tshuam kev cuam tshuam thiab kev cuam tshuam ze ntawm thaj chaw.
1.2 Lub mechanism ntawm electromagnetic cuam tshuam
1.2.1 Electromagnetic cuam tshuam tsim los ntawm kev hloov circuits
Lub tshuab hluav taws xob hloov hluav taws xob yog lub hauv paus ntawm lub zog hloov hluav taws xob. Nws yog tsuas yog tsim los ntawm lub raj hloov pauv thiab lub tshuab hluav taws xob ntau zaus. Lub dv/dt generated los ntawm nws yog ib tug mem tes nrog ib tug kuj loj amplitude, ib tug dav zaus band thiab nplua nuj harmonics. Muaj ob lub laj thawj tseem ceeb rau qhov kev cuam tshuam ntawm cov mem tes no: ntawm ib sab, qhov hloov lub raj thauj khoom yog thawj kauj ntawm lub tshuab hluav taws xob ntau zaus, uas yog qhov inductive load. Thaum lub sij hawm thaum lub hloov lub raj yog qhib, lub hauv paus kauj tsim ib tug loj inrush tam sim no, thiab ib tug high surge ncov voltage tshwm nyob rau hauv ob qho tib si kawg ntawm thawj kauj; Thaum lub qhov hluav taws xob hloov hluav taws xob raug muab tua, vim yog cov dej ntws tawm ntawm lub hauv paus kauj, ib feem ntawm lub zog Yog tias tsis muaj kev sib kis ntawm thawj kauj mus rau theem ob, qhov no ntawm lub zog khaws cia hauv lub inductor yuav tsim ib qho attenuating. oscillation nrog ib tug spike nrog lub capacitance thiab kuj nyob rau hauv lub collector Circuit Court, uas yog superimposed nyob rau hauv lub turn-off voltage los tsim ib tug tig-off voltage spike. Qhov kev cuam tshuam ntawm lub zog hluav taws xob no yuav ua rau tib lub magnetizing inrush tam sim no ib ntus raws li thaum lub hauv paus kauj yog qhib, thiab lub suab nrov no yuav raug coj mus rau cov tswv yim thiab cov zis tawm los tsim kev cuam tshuam. Ntawm qhov tod tes, lub siab hloov pauv tam sim no lub voj voog tsim los ntawm thawj kauj ntawm lub mem tes transformer, lub raj hloov thiab lub lim capacitor tuaj yeem tsim hluav taws xob ntau qhov chaw thiab tsim hluav taws xob cuam tshuam.
1.2.2 Kev cuam tshuam los ntawm lub sijhawm rov qab los ntawm lub diode Thaum lub diode rectifier nyob rau hauv lub high-frequency rectification circuit yog forward-conducting, ib tug loj rau pem hauv ntej tam sim no ntws los ntawm nws. Thaum nws rov qab-biased thiab tig mus rau kev txiav tawm, vim muaj ntau cov cab kuj sib sau ua ke, yog li tam sim no yuav ntws mus rau qhov tsis sib xws rau ib lub sijhawm ua ntej cov nqa khoom ploj mus, ua rau muaj kev poob qis hauv kev rov qab los. tam sim no ntawm cov cab kuj ploj lawm thiab ib tug loj tam sim no hloov
