Kho thiab txij nkawm ntawm digital multimeter
1. Kev tu
Cov multimeter digital yog cov cuab yeej hluav taws xob precision, tsis txhob hloov lub voj voog ntawm qhov xav tau, thiab xyuam xim rau cov ntsiab lus hauv qab no:
⒈Tsis txhob txuas siab dua 1000V DC voltage lossis siab dua 700V AC RMS voltage.
2. Tsis txhob txuas qhov hluav taws xob qhov hluav taws xob thaum lub zog hloov pauv nyob rau hauv Ω thiab txoj haujlwm.
3. Thov tsis txhob siv lub moos no thaum lub roj teeb tsis tau teeb tsa lossis lub hau rov qab tsis nruj.
2. Kho txoj kev
Digital multimeters muaj siab rhiab heev thiab raug, thiab lawv daim ntawv thov muaj nyob rau hauv yuav luag txhua lub lag luam. Txawm li cas los xij, vim muaj ntau yam ntawm nws qhov kev ua tsis tiav, thiab qhov randomness ntawm cov teeb meem tau ntsib, tsis muaj ntau txoj cai ua raws. Qee qhov kev kho mob uas tau sau tseg hauv kev ua haujlwm tiag tiag raug txheeb xyuas los ntawm cov npoj yaig koom nrog hauv qhov loj no.
Thaum nrhiav kev txhaum, koj yuav tsum pib ntawm sab nraud thiab tom qab ntawd sab hauv, ua ntej qhov yooj yim thiab tom qab ntawd qhov nyuaj, rhuav tshem lawv mus rau hauv qhov chaw, thiab ua kom tawg ntawm cov ntsiab lus tseem ceeb. Cov txheej txheem tuaj yeem kwv yees faib ua pawg hauv qab no:
1. Kev xav
Siv qhov kev nkag siab los txiav txim ncaj qha rau qhov ua txhaum. Los ntawm kev tshuaj xyuas qhov muag, koj tuaj yeem nrhiav tau xws li kev sib txuas, desoldering, luv luv Circuit Court, tawg fuse tube, hlawv cov khoom, kev puas tsuaj rau cov khoom siv, tooj liab ntawv nyiaj lifting thiab tawg ntawm cov luam tawm Circuit Court, thiab lwm yam.; Koj tuaj yeem kov qhov kub thiab txias ntawm lub roj teeb, resistors, transistors, thiab kev sib xyaw ua ke, thiab koj tuaj yeem xa mus rau daim duab kos duab kom paub seb yog vim li cas rau qhov kub tsis txawv txav. Tsis tas li ntawd, los ntawm txhais tes, koj tuaj yeem tshawb xyuas seb cov khoom puas yog xoob, seb cov pins sib xyaw ua ke tau ruaj khov, thiab seb qhov hloov pauv hloov yog daig; koj tuaj yeem hnov thiab hnov txog seb puas muaj suab txawv txav thiab tsw.
2. Txoj kev ntsuas hluav taws xob
Los ntawm kev ntsuas seb qhov ua haujlwm voltage ntawm txhua lub ntsiab lus tseem ceeb yog qhov qub, qhov yuam kev tuaj yeem pom sai sai. Xws li ntsuas qhov ua haujlwm voltage thiab siv voltage ntawm A / D converter.
⒊ Short circuit method
Nyob rau hauv txoj kev tshawb xyuas A / D converter tau hais los saum no, feem ntau siv txoj kev luv luv. Txoj kev no feem ntau siv thaum kho cov twj tsis muaj zog thiab micro-hluav taws xob.
⒋ txoj kev tawg ntawm lub voj voog
Tshem tawm qhov tsis txaus ntseeg los ntawm tag nrho lub tshuab lossis lub tshuab hluav taws xob. Yog hais tias qhov txhaum ploj mus, nws txhais tau hais tias qhov txhaum nyob rau hauv lub disconnected Circuit Court. Cov qauv no feem ntau haum rau qhov xwm txheej uas muaj qhov luv luv hauv Circuit Court.
5. Kev ntsuas cov txheej txheem
Thaum qhov ua txhaum tau nqaim mus rau ib lossis ob peb yam, nws tuaj yeem ntsuas hauv online lossis offline. Yog tias tsim nyog, hloov nws nrog qhov zoo. Yog tias qhov txhaum ploj mus, cov khoom tawg.
3. Kho kev txawj ntse
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 voltage 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 lub 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 tau ua raws.
