Cov txheej txheem digital multimeter daws teeb meem thiab kho cov txheej txheem
Rau cov cuab yeej faulty, thawj kauj ruam yog los xyuas thiab paub qhov txawv ntawm qhov tshwm sim txhaum cai (tag nrho cov haujlwm tsis tuaj yeem ntsuas) lossis tus kheej (tus kheej lub luag haujlwm lossis ntau yam), thiab tom qab ntawd paub qhov txawv ntawm qhov xwm txheej thiab daws nws raws li.
Yog tias txhua lub zog tsis tuaj yeem ua haujlwm, lub hwj huam mov Circuit Court thiab A / D converter circuit yuav tsum tau ua tib zoo xyuas. Thaum kuaj xyuas cov khoom siv hluav taws xob, tshem cov roj teeb uas sib dhos, nias lub hwj huam hloov, txuas qhov zoo sojntsuam mus rau qhov tsis zoo ntawm lub ntsuas hluav taws xob ntsuas hluav taws xob, thiab txuas cov kev sojntsuam tsis zoo mus rau sab zoo ntawm lub hwj chim (rau digital multimeter) . Tig qhov hloov mus rau qhov ntsuas txoj hauj lwm ntawm lub diode. Yog hais tias cov zaub qhia qhov zoo voltage ntawm lub diode, nws qhia tau hais tias lub hwj chim mov yog zoo. Yog tias qhov sib txawv loj, nws qhia tau hais tias muaj teeb meem nrog cov khoom siv hluav taws xob. 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 kev cuam tshuam luv luv, nws yuav tsum tau siv txoj kev sib txuas hauv Circuit Court kom maj mam txiav cov khoom siv hluav taws xob, thiab tsom mus rau kev tshuaj xyuas cov khoom siv hluav taws xob ua haujlwm, timer, thiab A / D converter. Yog hais tias ib tug luv luv Circuit Court tshwm sim, nws feem ntau puas ntau tshaj ib tug integrated tivthaiv. Lub A / D converter tuaj yeem tshawb xyuas ib txhij nrog lub ntsuas qhov yooj yim, uas yog sib npaug rau DC meter taub hau ntawm analog multimeter. Txoj kev tshuaj xyuas tshwj xeeb yog:
(1) Tig qhov ntau ntawm cov ntsuas ntsuas mus rau qhov qis tshaj ntawm DC voltage;
(2) 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 piv cov ntsuas qhov tseem ceeb nrog lawv cov nqi ib txwm rau tus coj V + thiab COM pins.
(3) Kev siv hluav taws xob siv rau kev ntsuas A / D converters feem ntau yog 100mV lossis 1V rau cov khoom siv digital multimeters, uas ntsuas DC voltage ntawm VREF + 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 + thiab tsis zoo davhlau ya nyob twg IN - ntawm lub A/D converter, kom cov input voltage Vin=0 thiab cov twj paj nruag qhia "{{5 }}.0" or "00.00".
(5) Txheeb xyuas qhov ci ntsa iab tag nrho ntawm lub monitor. luv luv Circuit Court tus pin xeem rau qhov zoo fais fab mov davhlau ya nyob twg V +, ua rau lub logic hauv av los ua siab muaj peev xwm thiab tag nrho cov digital circuits tsis ua hauj lwm. Vim tias qhov hluav taws xob DC siv rau txhua qhov mob stroke, txhua qhov strokes teeb thiab lub ntsuas ntsuas ntsuas "1888", thaum lub ntsuas ntsuas ntsuas "18888". Yog tias muaj qhov tshwm sim tsis muaj zog, xyuas seb puas muaj kev sib cuag tsis zoo lossis xaim tawg ntawm cov zis tus pin ntawm A / D converter thiab cov nplaum nplaum (lossis thaiv), thiab cov zaub.
Yog tias muaj teeb meem nrog qee cov ntaub ntawv tus kheej, nws qhia tau hais tias ob qho tib si A / D converter thiab cov khoom siv hluav taws xob ua haujlwm zoo. Vim hais tias DC voltage thiab kuj ntau yam sib koom ua ke ntawm voltage divider resistors; AC / DC tam sim no sib faib splitter; AC voltage thiab AC tam sim no sib koom ua ke ntawm AC / DC converters; Lwm yam khoom xws li Cx, HFE, F, thiab lwm yam yog tsim los ntawm kev ywj pheej thiab sib txawv converters. Nkag siab txog kev sib raug zoo ntawm lawv, thiab tom qab ntawd raws li daim duab hluav taws xob, nws yog qhov yooj yim los nrhiav qhov tsis raug. Yog tias qhov ntsuas me me tsis raug lossis cov lej tso tawm muaj qhov hloov pauv loj, 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 khaws cia, luv luv Circuit Court input davhlau ya nyob twg ntawm A / D converter, thiab cov ntaub ntawv tso tawm tsis yog xoom, ces nws feem ntau yog 0.1 μ Ua los ntawm kev ua haujlwm tsis zoo ntawm F's benchmark capacitor.
Raws li cov kev soj ntsuam saum toj no, qhov kev txiav txim siab ntawm kev kho lub tshuab hluav taws xob digital yuav tsum yog: lub taub hau digital meter → DC voltage → DC tam sim no → AC voltage → AC tam sim no → tsis kam (nrog rau buzzer thiab xyuas qhov zoo voltage poob ntawm ob lub raj) → Cx → HFE, F, H, T, thiab lwm yam. Tab sis nws yuav tsum tsis txhob overly mechanical. Qee qhov teeb meem pom tseeb tuaj yeem daws tau ua ntej. Tab sis thaum ua calibration, nws yuav tsum tau ua raws li cov txheej txheem saum toj no.
Nyob rau hauv luv luv, ib tug faulty multimeter, tom qab kev ntsuam xyuas tsim nyog, thawj yuav tsum tau 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 qhov tseeb tias digital multimeter yog ib qho cuab yeej meej dua, thaum hloov cov khoom siv, nws yog ib qho tsim nyog yuav tsum siv cov khoom siv nrog tib qhov tsis zoo, tshwj xeeb tshaj yog thaum hloov A / D converters. Cov chaw tsim khoom ua tib zoo xaiv cov kev sib xyaw ua ke yuav tsum tau siv, txwv tsis pub muaj qhov yuam kev tuaj yeem tshwm sim thiab qhov yuav tsum tau ua kom raug yuav tsis ua tiav. Qhov hloov tshiab A / D converter kuj yuav tsum tau kuaj xyuas raws li txoj kev tau piav qhia ua ntej, thiab yuav tsum tsis txhob ntseeg vim nws qhov tshiab.
