Kho txoj kev ntawm digital multimeter
Rau cov cuab yeej faulty, thawj zaug xyuas thiab txiav txim seb qhov kev ua txhaum tshwm sim puas muaj tshwm sim (tag nrho cov haujlwm tsis tuaj yeem ntsuas) lossis tus kheej (kev ua haujlwm ntawm tus kheej lossis tus kheej ntau), thiab tom qab ntawd paub qhov txawv qhov xwm txheej thiab daws nws cov tsos mob.
1. Yog tias txhua lub zog tsis ua haujlwm, ua tib zoo saib xyuas cov khoom siv hluav taws xob thiab A / D converter circuit. Thaum kuaj xyuas cov khoom siv hluav taws xob, koj tuaj yeem tshem tawm cov roj teeb laminated, nias lub hwj huam hloov, txuas qhov kev ntsuam xyuas zoo ua rau qhov tsis zoo ntawm lub zog hluav taws xob ntawm lub ntsuas hluav taws xob nyob rau hauv kev sim, thiab qhov ntsuas tsis zoo ua rau lub zog zoo (rau digital. multimeters), thiab hloov mus rau qhov ntsuas diode. Yog hais tias qhov hluav taws xob pem hauv ntej ntawm lub diode yog siab dua, nws txhais tau hais tias lub hwj huam mov yog qhov zoo. Yog hais tias qhov sib txawv loj, nws txhais tau hais tias muaj teeb meem nrog lub hwj huam mov. Yog tias muaj qhov qhib Circuit Court, tsom mus rau kev kuaj xyuas lub hwj chim hloov thiab cov roj teeb coj. Yog tias muaj qhov luv luv, koj yuav tsum siv txoj kev qhib Circuit Court kom maj mam txiav cov khoom siv hluav taws xob, thiab tsom mus rau kev kuaj xyuas lub tshuab ua haujlwm, lub sijhawm thiab A / D converter. Nyob rau hauv qhov kev tshwm sim ntawm ib tug luv luv Circuit Court, feem ntau ntau tshaj ib tug integrated tivthaiv yog puas. Kev kuaj xyuas A / D converter tuaj yeem ua tiav ib txhij nrog lub ntsuas ntsuas, uas yog sib npaug rau DC meter taub hau ntawm analog multimeter. Txoj kev kuaj xyuas tshwj xeeb:
⑴ Qhov ntau ntawm cov ntsuas ntsuas tau tig mus rau qib qis tshaj ntawm DC voltage;
⑵ Ntsuas seb qhov ua haujlwm voltage ntawm A / D converter yog qhov qub. Raws li A / D converter qauv siv nyob rau hauv lub rooj, sib xws rau V ntxiv tus pin thiab COM tus pin, seb tus nqi ntsuas yog raws li nws tus nqi raug.
(3) Ntsuas qhov siv hluav taws xob ntawm A / D converter. Qhov kev siv hluav taws xob ntawm ib qho kev siv digital multimeter feem ntau yog 100mV lossis 1V, uas yog, ntsuas qhov DC voltage ntawm VREF ntxiv thiab COM. Yog tias nws deviates ntawm 100mV lossis 1V, nws tuaj yeem hloov kho los ntawm lwm tus potentiometer.
(4) Txheeb xyuas tus lej xov tooj nrog xoom input, luv-circuit qhov zoo davhlau ya nyob twg IN ntxiv thiab qhov tsis zoo davhlau ya nyob twg IN- ntawm A/D converter ua rau cov input voltage Vin=0, thiab lub meter qhia "{{ 4}} 0" or "00.00".
⑸ Txheeb xyuas qhov ci ntsa iab tag nrho ntawm cov zaub. Luv luv lub xeem davhlau ya nyob twg TEST tus pin thiab qhov zoo fais fab mov davhlau ya nyob twg V ntxiv, ua rau lub logic hauv av ua lub peev xwm siab, thiab tag nrho cov digital circuits nres ua haujlwm. Vim tias qhov hluav taws xob DC ntxiv rau txhua qhov mob stroke, tag nrho cov strokes ci ntsa iab thiab cov lus sib dhos qhia tau hais tias "1888", thiab lub rooj sib dhos qhia tau hais tias "18888". Yog tias tsis muaj kev cuam tshuam tsis zoo, xyuas seb puas muaj kev sib cuag tsis zoo lossis kev cuam tshuam ntawm cov khoom sib txuas ntawm tus pin A / D converter thiab cov kua nplaum conductive (lossis kev sib txuas), thiab cov zaub.
2. Yog hais tias muaj teeb meem nrog ib tug neeg cov ntaub ntawv, nws txhais tau hais tias lub A / D converter thiab lub hwj chim mov ua hauj lwm ib txwm. Vim tias DC voltage thiab cov ntaub ntawv tsis kam sib koom ua ke ntawm voltage faib cov resistors; AC thiab DC tam sim no sib koom shunt; AC voltage thiab AC tam sim no sib koom ua ke ntawm AC / DC converters; lwm yam xws li Cx, HFE, F, thiab lwm yam yog tsim los ntawm cov kev ywj pheej sib txawv converters . Nkag siab txog kev sib raug zoo ntawm lawv, thiab tom qab ntawd raws li daim duab qhia lub zog, nws yooj yim los nrhiav qhov chaw txhaum. Yog tias qhov ntsuas ntawm cov cim me me tsis raug lossis cov naj npawb pom tau dhia zoo heev, ces tsom mus xyuas seb qhov kev sib cuag ntawm qhov hloov pauv yog qhov zoo.
3. Yog tias cov ntaub ntawv ntsuas tsis ruaj khov thiab tus nqi ib txwm nce ntxiv, luv luv ntawm cov khoom siv hluav taws xob ntawm A / D converter thiab cov ntaub ntawv tso tawm tsis yog xoom, nws feem ntau tshwm sim los ntawm kev ua haujlwm tsis zoo ntawm 0 .1μF siv capacitor.
Raws li cov kev soj ntsuam saum toj no, cov theem pib ntawm kev kho digital multimeter yuav tsum yog: digital meter taub hau → DC voltage → DC tam sim no → AC voltage → AC tam sim no → cov ntaub ntawv tsis kam (xws li buzzer thiab xyuas qhov zoo voltage poob ntawm lub diode) → Cx → HFE , F , H , T , thiab lwm yam. Tab sis tsis txhob ua heev mechanical. Qee qhov teeb meem pom tseeb tuaj yeem daws tau ua ntej. Txawm li cas los xij, thaum kho, cov txheej txheem saum toj no yuav tsum ua raws.
Nyob rau hauv luv luv, tom qab kev soj ntsuam kom zoo ntawm ib tug faulty multimeter, nws yog tsim nyog los soj ntsuam qhov ua tau qhov chaw ntawm qhov txhaum, thiab ces nrhiav qhov txhaum qhov chaw raws li daim duab Circuit Court rau hloov thiab kho. Vim hais tias cov multimeter digital yog cov cuab yeej siv tau zoo, cov khoom siv nrog cov tsis zoo ib yam yuav tsum tau siv los hloov cov khoom siv, tshwj xeeb tshaj yog rau kev hloov ntawm A / D converters, cov kev sib xyaw ua ke uas tau raug soj ntsuam nruj me ntsis los ntawm cov chaw tsim khoom yuav tsum tau siv, txwv tsis pub yuav yuam kev. tshwm sim thiab cov khoom uas yuav tsum tau ua yuav tsis raug. Qhov tseeb. Cov hloov tshiab A / D hloov tshiab kuj yuav tsum tau kuaj xyuas raws li cov txheej txheem hais saum toj no, thiab nws yuav tsum tsis txhob ntseeg vim nws qhov tshiab.
