Yuav ua li cas tiv thaiv switching fais fab mov ripple
Generation ntawm Ripple hauv Switching Power Supply
Peb lub hom phiaj yog kom txo cov zis ripple mus rau theem siab, thiab cov kev daws teeb meem tseem ceeb kom ua tiav lub hom phiaj no yog kom tsis txhob muaj lub cim ntawm ripple ntau li ntau tau. Ua ntej, peb yuav tsum tau qhia meej txog hom thiab ua rau ripple nyob rau hauv lub switching fais fab mov.
Tom qab qhov hloov ntawm SWITCH, tam sim no hauv inductor L kuj hloov pauv nce thiab nqis hauv qhov txiaj ntsig zoo ntawm cov zis tam sim no. Yog li tseem yuav muaj ib qho ripple ntawm cov zis kawg nrog tib zaus li SWITCH, uas feem ntau hu ua ripple. Nws muaj feem xyuam rau lub peev xwm thiab ESR ntawm cov zis capacitor. Qhov zaus ntawm qhov ripple no zoo ib yam li ntawm kev hloov hluav taws xob, xws li kaum mus rau ntau pua KHz.
Tsis tas li ntawd, SWITCH feem ntau siv bipolar transistors lossis MOSFETs. Txawm hais tias ib qho twg siv, yuav muaj lub sijhawm nce thiab lub caij nplooj zeeg thaum nws qhib thiab tawm. Nyob rau ntawm lub sijhawm no, lub suab nrov nrog tib zaus lossis khib ntau ntawm SWITCH nce thiab lub caij nplooj zeeg yuav tshwm sim hauv Circuit Court, feem ntau nyob rau hauv kaum ntawm MHz. Thaum lub sijhawm rov qab rov qab, qhov sib npaug ntawm lub diode D yog kev sib txuas ntawm kev tiv thaiv, kev ua haujlwm, thiab inductance, uas tuaj yeem ua rau resonance thiab tsim suab nrov ntau zaus ntawm ntau kaum ntawm MHz. Ob hom suab nrov no feem ntau hu ua suab nrov nrov, thiab lawv qhov amplitude feem ntau loj dua ripple.
Yog tias nws yog AC / DC converter, ntxiv rau ob hom ripple (suab nrov) uas tau hais los saum no, kuj tseem muaj AC suab nrov, uas yog qhov zaus ntawm cov khoom siv hluav taws xob AC, nyob ib ncig ntawm 50-60Hz. Kuj tseem muaj hom suab nrov nrov, uas yog tshwm sim los ntawm qhov sib npaug ntawm cov khoom siv hluav taws xob tsim los ntawm cov khoom siv hluav taws xob ntawm ntau cov khoom siv hluav taws xob hloov hluav taws xob siv cov ntaub thaiv npog ua cov dab dej kub. Raws li kuv tau koom nrog kev tshawb fawb thiab kev tsim kho tsheb hauv tsheb, kuv muaj tsawg dua rau ob hom suab nrov tom qab, yog li kuv tsis xav txog lawv tam sim no.
Kev ntsuas ntawm Ripple hauv Switching Power Supply
Cov kev cai yooj yim: Siv oscilloscope AC coupling, 20MHz bandwidth txwv, unplug lub sojntsuam cov av xaim
1. AC coupling yog cov txheej txheem ntawm kev tshem tawm cov superimposed DC voltage kom tau txais qhov tseeb waveform.
2. Qhib 20MHz bandwidth txwv yog los tiv thaiv kev cuam tshuam los ntawm lub suab nrov nrov thiab tiv thaiv kev ntsuas qhov yuam kev. Vim qhov loj amplitude ntawm high-frequency Cheebtsam, lawv yuav tsum tau muab tshem tawm thaum lub sij hawm ntsuas.
3. Tshem tawm qhov txuas hauv av ntawm lub oscilloscope sojntsuam thiab ntsuas nrog lub nplhaib hauv av kom txo tau kev cuam tshuam. Ntau qhov chaw tsis muaj cov nplhaib hauv av, thiab yog tias qhov ua yuam kev tau txais, lawv tuaj yeem ntsuas ncaj qha los ntawm kev sojntsuam cov khoom siv hauv av. Tab sis qhov tseem ceeb no yuav tsum tau xav txog thaum txiav txim siab seb nws puas tsim nyog.
Lwm qhov taw qhia yog siv lub davhlau ya nyob twg 50 Ω. Raws li cov ntaub ntawv ntawm Yokogawa oscilloscope, 50 Ω module ntsuas AC tivthaiv tom qab tshem tawm DC tivthaiv. Txawm li cas los xij, ob peb oscilloscopes tau nruab nrog cov kev sojntsuam tshwj xeeb. Feem ntau, cov qauv sojntsuam xws li 100K Ω txog 10M Ω yog siv rau kev ntsuas, thiab qhov cuam tshuam tam sim no tsis meej.
Cov saum toj no yog cov kev ceev faj yooj yim thaum ntsuas hloov ripple. Yog hais tias lub oscilloscope sojntsuam tsis ncaj qha mus cuag cov zis taw tes, nws yuav tsum tau ntsuas siv twisted khub cables los yog 50 Ω coaxial cables.
Thaum ntsuas lub suab nrov nrov, tag nrho passband ntawm ib qho oscilloscope feem ntau nyob hauv thaj tsam ntawm ntau pua megahertz rau GHz. Lwm tus yog tib yam li saum toj no. Cov tuam txhab sib txawv tuaj yeem muaj cov kev sim sib txawv. Thaum kawg, nws yog ib qho tseem ceeb kom muaj kev nkag siab meej ntawm tus kheej cov txiaj ntsig kev xeem ** kom tau txais kev lees paub ntawm cov neeg siv khoom.
