Cov ntsiab lus tseem ceeb rau kev hloov cov khoom siv hluav taws xob
Thaum debugging lub zog hloov pauv, ntxiv rau kev siv lub voltmeter los ntsuas qhov voltage ntawm tus pins ntawm cov khoom muaj feem xyuam hauv kev tswj xyuas Circuit Court, nws yog ib qho tseem ceeb uas yuav tsum tau siv lub oscilloscope los soj ntsuam qhov cuam tshuam qhov hluav taws xob waveforms txhawm rau txiav txim seb lub zog hloov pauv. kev muab khoom yog nyob rau hauv qhov kev ua haujlwm zoo tshaj plaws. Kab lus no feem ntau piav qhia txog kev xaiv ntawm oscilloscope xeem cov ntsiab lus. Piv txwv li, thaum qhov ntsuas qhov ntsuas yog qhov tso zis tus pin ntawm PWM tswj nti, ib qho oscilloscope tuaj yeem siv los ntsuas ob qho tseem ceeb ntawm kev tsav tsheb pulse amplitude thiab lub voj voog ua haujlwm.
Kev xaiv cov ntsiab lus xeem yog qhov tseem ceeb heev. Kev xaiv tsim nyog ntawm cov ntsiab lus xeem tuaj yeem tsis tsuas yog ua kom muaj kev nyab xeeb ntawm kev debugging, tab sis kuj tseem cuam tshuam txog kev ua haujlwm ntawm kev hloov hluav taws xob thiab ua kom yooj yim rau kev debugging.
Test point xaiv ntawm switching fais fab mov Lub xeem point TP1 yog qhov ntws ntawm MOSFET lub hwj chim hloov raj, TP2 yog lub hauv paus ntawm lub hloov raj, Rs yog tam sim no sampling resistor, thiab TP3 yog tus ncej tsis zoo ntawm thawj high-voltage circuit. . Peb tuaj yeem txuas ob lub ntsiab lus ntsuas TP1 thiab TP2 mus rau ob qhov kev tawm tswv yim (CH1 thiab CH2) ntawm ob txoj kab ke oscilloscope, thiab saib xyuas qhov voltage waveforms ntawm ob lub ntsiab lus tib lub sijhawm. Nyob rau lub sijhawm no, hauv av terminals ntawm ob qhov kev sojntsuam yuav tsum tau txuas nrog tus ncej tsis zoo ntawm thawj lub tswv yim DC Circuit Court tib lub sijhawm, uas yog, txoj haujlwm TP3. Thaum lub sij hawm qhov tseeb ntsuas, lub hauv av clip ntawm kev sojntsuam yuav raug clamped ncaj qha rau hauv av tus pin ntawm Rs.
Los ntawm TP1, peb tuaj yeem pom cov dej ntws tawm ntawm lub hwj chim hloov raj. Qhov no waveform muaj peev xwm cuam tshuam cov ntaub ntawv xws li ntws peak voltage, input DC high voltage, theem nrab reflection voltage, hloov raj conduction voltage poob, thiab conduction thiab txiav tawm lub sij hawm. Nyob rau hauv ib qho kawg flyback switching fais fab mov, qhov ntws voltage waveform ntawm lub hwj chim hloov raj
Los ntawm TP2, koj tuaj yeem pom qhov voltage waveform ntawm lub hwj chim hloov raj. Qhov no waveform yog qhov voltage waveform ntawm tus qauv resistor Rs, uas muaj peev xwm cuam tshuam cov ntaub ntawv xws li ntws tam sim no, tig-on thiab tig-tawm lub sij hawm. Cov dej ntws tam sim no waveform ntawm lub hwj chim hloov raj. Qhov no waveform qhia tau hais tias lub zog hloov hluav taws xob ua haujlwm hauv hom tam sim no tsis tu ncua. Nyob rau hauv txhua lub voj voog, thaum lub raj hloov pauv tau qhib, qhov ntws tawm tam sim no pib nce los ntawm qhov tsawg kawg nkaus pib tam sim no. Ua ntej lub qhov hluav taws xob hloov hluav taws xob raug muab tua, cov dej ntws mus txog qhov siab tshaj plaws.
Ob lub ntsiab lus ntsuas TP1 thiab TP2 yog qhov tseem ceeb heev, thiab tuaj yeem cuam tshuam txog kev ua haujlwm ntawm lub zog hloov hluav taws xob thiab seb puas muaj qhov yuam kev. Thaum lub sij hawm debugging, xyuam xim tshwj xeeb rau lub waveforms ntawm ob lub ntsiab lus xeem no. Thaum maj mam nce cov input AC voltage, yog hais tias lub ncov voltage los yog ncov tam sim no tshaj qhov tsim ntau yam, lub hwj huam mov yuav tsum tau muab tua tam sim ntawd kom paub qhov ua rau kom tsis txhob muaj kev puas tsuaj rau lub hwj chim hloov raj.
Qee lub sij hawm, txhawm rau soj ntsuam qhov tam sim no waveform ntawm thawj winding ntawm high-frequency transformer, ib qho piv txwv resistor kuj tuaj yeem txuas nrog cov thawj winding. Rau qhov piv txwv Circuit Court ntawm thawj lub voj tam sim no, qhov ntsuas lub xeev ntawm lub sijhawm no yog qhov ntsuas "floating" uas tau hais hauv tsab xov xwm dhau los. Kev hais lus theoretical, tus qauv tiv thaiv tuaj yeem txuas nrog hauv koob ntawm qhov kawg lossis qis kawg ntawm thawj winding; Nyob rau hauv qhov tseeb, yog hais tias nws yog txuas nrog nyob rau hauv series nyob rau hauv qis kawg ntawm thawj winding, saib Rs1 txoj hauj lwm nyob rau hauv daim duab, ib tug floating high-voltage mem tes yuav tsim nyob rau hauv lub oscilloscope av xaim thaum ntsuas. Nws tsis muaj kev nyab xeeb los ua li ntawd, tab sis kuj ua rau muaj kev cuam tshuam loj thiab ua yuam kev, thiab tseem tuaj yeem cuam tshuam rau kev ua haujlwm ntawm lub zog hloov pauv. Txoj kev raug yog txuas cov qauv resistor nyob rau hauv series nrog rau sab sauv kawg ntawm thawj winding, saib Rs txoj hauj lwm nyob rau hauv daim duab, thiab txuas lub teeb liab kab ntawm oscilloscope sojntsuam ntawm TP1 kawg, thiab txuas lub grounding clip ntawm lub sojntsuam. ntawm TP2 kawg. Nyob rau hauv txoj kev no, txawm hais tias lub waveform ntawm thawj lub voj voj voog yog rov qab polarity, kev cuam tshuam thiab kev ua yuam kev thaum ntsuas yog tsawg, thiab tsis muaj kev cuam tshuam rau kev ua haujlwm ntawm lub zog hloov pauv. Thawj qhov tam sim no waveform ntawm qhov zoo polarity tuaj yeem pom los ntawm qhov rov qab polarity (INV) ua haujlwm khawm ntawm oscilloscope.
Cov lus ceeb toom tshwj xeeb: Thaum soj ntsuam thawj qhov tam sim no waveform ntawm high-frequency transformer, hauv av clip ntawm oscilloscope sojntsuam yuav txuas mus rau qhov zoo kawg ntawm DC high voltage. Cov kev sojntsuam thiab hauv av clips ntawm lwm txoj hauv kev ntawm oscilloscope yuav tsum raug txiav tawm ntawm cov khoom siv hluav taws xob, txwv tsis pub lub voj voog luv luv yuav tshwm sim lossis cov khoom ntawm lub voj voog yuav puas. Qhov ntawd yog hais tias, thaum soj ntsuam thawj thawj lub voj voog tam sim no, tsuas yog ib qho channel tuaj yeem siv tau, thiab lwm cov channel yuav tsum raug txiav tag nrho. Qhov teeb meem no tsis muaj nyob thaum siv oscilloscopes nrog built-in cais channel technology.
