Lub ripple factor thiab lub zog mov
Lub luag haujlwm tseem ceeb ntawm cov khoom siv hluav taws xob yog muab hluav taws xob hluav taws xob rau cov khoom siv hluav taws xob, tab sis nws yuav inevitably qhia ripples, suab nrov, thiab lwm yam thaum lub sij hawm siv hluav taws xob, uas yuav txo tau qhov ruaj khov thiab kev ntseeg siab ntawm cov khoom siv hluav taws xob thiab txawm tias tag nrho cov khoom.
Voltage ripple tuaj yeem cuam tshuam ntau yam ntawm lub zog hluav taws xob, xws li A / D hloov hluav taws xob Circuit Court, ua haujlwm amplifier circuit, rectifier lim circuit, thiab lwm yam. Cov ntawv siv feem ntau muaj cov teeb meem hauv qab no:
Cov kev sib raug zoo uas tsis tau npaj tseg yog tsim los ua kom muaj xwm txheej tshwm sim los ntawm overvoltage lossis overcurrent; nce ntxiv poob thiab txo qhov ua tau zoo thiab kev siv cov khoom siv hluav taws xob;
Ua kom cov cuab yeej ua haujlwm txawv txav, ua kom muaj kev laus, thiab ua kom lub neej ua haujlwm luv; ua kev tiv thaiv relay, cov khoom siv tsis siv neeg, tshuab computer thiab lwm yam khoom siv ua haujlwm txawv txav lossis ua haujlwm tsis tu ncua;
Ua kom ntsuas thiab ntsuas ntsuas qhov sib txawv; cuam tshuam nrog kev sib txuas lus, txo cov teeb liab kis tau tus mob zoo, thiab txawm tias cov khoom siv kev sib txuas lus puas.
Yog li ntawd, thaum tsim cov khoom siv hluav taws xob, nws yog ib qho tsim nyog yuav tsum ntsuas qhov ripple thiab suppress lub ripple nyob rau hauv ib qho chaw.
1 Lub zog muab ripple thiab ripple yam
Hais lus nruj me ntsis, cov khoom siv hluav taws xob ruaj khov muaj xws li plaub ntu: lub zog hloov hluav taws xob, hluav taws xob rectifier, lim circuit thiab voltage stabilizer circuit. Txij li thaum DC-DC tuaj yeem suav tau tias yog lub zog ruaj khov, lub tshuab hluav taws xob rectifier, lim circuit thiab stabilized voltage Circuit Court raug suav tias yog qhov tsim nyog peb feem ntawm cov khoom siv hluav taws xob ruaj khov [1].
Lub rectifier Circuit Court siv unidirectional conductive li los hloov alternating tam sim no mus rau pulsating ncaj tam sim no. Lub pulsating direct tam sim no tsis du thiab muaj ib tug loj npaum li cas ntawm alternating tam sim no.
Lub lim lim siv lub zog cia khoom los hloov cov pulsating ncaj qha tam sim no rau hauv qhov ncaj ncaj tam sim no. Vim qhov kev ua tau zoo sib txawv ntawm cov lim lim, txawm hais tias feem ntau ntawm cov khoom sib hloov tam sim no tuaj yeem lim tawm, lawv tsis tuaj yeem lim tawm tag nrho.
Lub voltage stabilizing Circuit Court tom qab rectification thiab filtering siv cov kev hloov kho ntawm lub Circuit Court kom stabilize cov zis voltage thiab txo cov AC tivthaiv kom tsawg. Qhov no AC tivthaiv uas tsis tuaj yeem lim tawm tag nrho nrog cov zis hluav taws xob ruaj khov yog hu ua ripple voltage.
Txhawm rau ua kom pom qhov ua haujlwm lim dej ntawm DC tswj fais fab mov, lub tswv yim ntawm ripple coefficient tau qhia [2-3]. Txhais lub ripple coefficient ψ raws li qhov feem pua tus nqi ntawm ripple voltage zoo nqi Vr thiab DC tso zis voltage Vo, uas yog:
Ripple coefficient yog qhov ntsuas tseem ceeb los ntsuas qhov ruaj khov thiab ntshiab tso zis ntawm DC fais fab mov. Raws li cov qauv saum toj no, nws tuaj yeem pom tau tias qhov ripple voltage yuav tsum tau ntsuas kom pom cov ripple coefficient.
2 Kev ntsuas qhov hluav taws xob ripple
Kev ntsuas qhov tseeb ntawm cov khoom siv hluav taws xob ripple feem ntau yuav tsum muaj ob lub cuab yeej, uas yog hluav taws xob thauj khoom (Electronic Load) thiab digital cia oscilloscope (Digital Storage Oscilloscope, DSO).
Cov khoom siv hluav taws xob tau yooj yim los kho qhov tam sim no, thiab nws feem ntau tau teeb tsa hauv hom tsis tu ncua (CR); cov digital cia oscilloscope tuaj yeem ncaj qha ntes tag nrho ripple waveform, khaws thiab nthuav nws, thiab nyeem tawm tus nqi ripple. Hloov cov oscilloscope nyeem rau hauv cov qauv kom tau txais qhov ripple yam.
Thaum ntsuas, koj yuav tsum tau xyuam xim rau ob lub ntsiab lus hauv qab no (ob lub ntsiab lus no tseem ceeb tshwj xeeb tshaj yog rau qhov tseeb ntawm qhov ntsuas ntsuas):
(1) Kev sojntsuam hauv av xaim ntawm digital cia oscilloscope yuav tsum tau muab tshem tawm thiab hloov nrog lub caij nplooj ntoo hlav hauv av hauv kev sojntsuam. Nws tuaj yeem tiv thaiv lub voj hauv av sib txuas rau hauv EMI suab nrov thiab ua rau qhov ntsuas tsis raug.
Lub hauv av xaim ntawm qhov kev sojntsuam ntev dhau lawm thiab lub voj voog cheeb tsam loj dhau lawm, tsim lub kav hlau txais xov, kev sib tsoo siab lossis EMI suab nrov yuav raug muab tso rau hauv qhov ntsuas ntsuas.
(2) Lub digital cia oscilloscope nws tus kheej yuav tsum tau kho qhov chaw.
Lub digital cia oscilloscope yuav tsum muaj lub hauv paus zoo los lim tawm cov khoom sib txuas ntxiv los ntawm cov khoom siv hluav taws xob; siv AC coupling ntawm cov digital cia oscilloscope los thaiv cov DC, ua rau cov ripple test ntau intuitive thiab raug;
Qhov kev sim ripple dav dav yuav tsum muaj qhov txwv qis dua 20MHz, yog li cov digital cia oscilloscope yuav tsum qhib 20MHz bandwidth txwv kom cais cov suab nrov nrov.
3 Txoj kev los txo hwj chim ripple
Txhawm rau tiv thaiv cov ripple ntawm cov zis hluav taws xob ntawm cov khoom siv hluav taws xob tswj hwm, plaub txoj hauv qab no feem ntau tau txais: RLC filtering method, hom hom lim lim, ferrite magnetic nplhaib filtering txoj kev thiab kev sib xyaw ntawm peb txoj kev.
Lub lim Circuit Court rau suppressing DC-DC fais fab mov ripple yog pom los ntawm kev sim ua pov thawj. Hauv kev sim ua pov thawj, 100W DC-DC fais fab mov nrog 48V tawm tswv yim thiab 5V cov zis raug xaiv, thiab tus qauv yog SD-100C-5 ntawm Meanwell.
Cov digital cia oscilloscope xaiv GDS-1072B ntawm GWINSTEK, bandwidth yog 70MHz, tus nqi piv txwv yog 1GSa/s, thiab qhov tob ntawm txhua channel yog 10M.
Cov khoom siv hluav taws xob yog PEL{{0}} los ntawm GWINSTEK, qhov ntsuas hluav taws xob yog 1.5V ~ 150V, qhov tam sim no yog 0 ~ 35A, thiab lub zog yog 175W.
Raws li qhov kev suav no, tam sim no hauv Circuit Court yog 20A. Daim duab 3 yog daim duab thaiv kev sib txuas ntawm lub zog ripple test.
Txhawm rau ua kom cov nyhuv ntawm suppressing lub hwj huam mov ripple ntau intuitive thiab pom tseeb, lub lim Circuit Court ntawm SD -100C-5 yog luv-circuited ua ntej, thiab lub ripple ntawm nws cov zis voltage yog ntsuas. Nws tuaj yeem tau txais tias lub zog hluav taws xob ripple yog kwv yees li 85.6mVpp, thiab tus nqi zoo yog 48.2mVrms.
