Multimeter Troubleshooting Circuit Board Faults
Lub hauv paus ntsiab lus ntawm multimeter yog siv lub rhiab magnetoelectric DC ammeter (microampere meter) ua lub taub hau meter. Thaum ib qho me me tam sim no dhau los ntawm lub taub hau meter, yuav muaj qhov qhia tam sim no. Txawm li cas los xij, lub taub hau 'meter' tsis tuaj yeem dhau qhov tam sim no loj, yog li qee qhov kev tiv thaiv yuav tsum tau txuas nrog nyob rau hauv parallel los yog series ntawm lub taub hau 'meter' kom shunt los yog txo qhov voltage, thiaj li ntsuas qhov tam sim no, voltage thiab kuj nyob rau hauv Circuit Court.
1. Xaiv qhov ntau: DC tam sim no ntau yam ntawm multimeter yog cim nrog "mA", thiab muaj peb qhov ntau: 1mA, 1omA, thiab 100mA. Qhov ntau yuav tsum tau xaiv raws li qhov tam sim no hauv Circuit Court. Yog tias qhov loj me tam sim no tsis paub, qhov siab tshaj plaws yuav tsum raug xaiv.
2. Kev ntsuas txoj kev: Lub multimeter yuav tsum tau txuas nrog hauv series nrog lub voj voog nyob rau hauv kev sim. Tom qab disconnect tus coj ib feem ntawm lub Circuit Court, txuas lub multimeter ua rau ob qho tag nrho ntawm lub breakpoint. Cov hlau lead kuaj liab yuav tsum tau txuas nrog lub breakpoint txuas nrog tus ncej zoo ntawm lub hwj huam mov, thiab cov hlau lead kuaj dub yuav tsum tau txuas nrog lub breakpoint txuas nrog cov ncej tsis zoo ntawm lub hwj huam mov.
3. Kev nyeem ntawv kom raug: Cov kab ntsuas ntawm DC tam sim no yog kab thib ob. Yog tias koj xaiv qhov 100mA ntau, koj tuaj yeem siv kab thib peb ntawm cov lej thiab muab faib los ntawm 10 tom qab nyeem ntawv.
Cov kauj ruam ntawm multimeter nrhiav tau Circuit Court
(1) Thaum ua cov kab txhaum kev tshawb nrhiav, tsis txhob ntxig qhov kev sojntsuam ntawm cov khoom siv kuaj rau hauv ib qho txuas lossis fuse lub thawv davhlau ya nyob twg, txwv tsis pub cov terminals feem ntau yuav deformed. Deformed terminals tuaj yeem ua rau kev sib cuag tsis zoo.
(2) Tom qab kuaj xyuas tias Circuit Court yog lawm, qhib lub hwj chim, thiab qhov ci ntawm lub teeb-emitting diode ntawm lub teb potentiometer yuav hloov. Ua kom lub teeb ci LED nruab nrab.
(3) Npaj lub multimeter raws li qhov yuav tsum tau hais los saum toj no ua ntej siv, thiab teeb tsa tus xaiv hloov mus rau Vl0 volt txoj hauj lwm.
(4) Tuav tus pas ntsuas hluav taws xob ntawm cov khoom siv lead ua, kov qhov ntsuas qhov zoo thiab qhov tsis zoo ua rau cov hlau lead-tawm soldering daim ntawm qhov zoo thiab qhov tsis zoo ntawm lub thawv roj teeb raws li, thiab ntsuas lub zog hluav taws xob. Nyeem tus nqi voltage kom raug.
Cov ntaub ntawv: Lub hwj chim mov voltage yog tus naj npawb ntawm volts.
(5) Kov qhov kev sim liab thiab xim dub coj ntawm lub multimeter mus rau ob tus pins ntawm lub teeb-emitting diode, thiab ntsuas qhov voltage ntawm ob tug ncej ntawm lub teeb-emitting diode. Nyeem tus nqi voltage kom raug.
Cov ntaub ntawv: qhov voltage volts hla lub teeb emitting diode.
(6) Ntsuas qhov ntsuas hluav taws xob hla lub ntsuas hluav taws xob ruaj khov nrog multimeter. Ua ntej txiav txim rau txoj haujlwm uas qhov kev xeem zoo thiab tsis zoo yuav tsum kov, thiab tom qab ntawd ntsuas.
Cov ntaub ntawv: Qhov hluav taws xob hla ntawm qhov hluav taws xob ruaj khov hauv volts.
Hauv qhov ntsuas peb-kauj ruam saum toj no, yog tias tus nqi hluav taws xob tsawg dua 2.5 volts, koj tuaj yeem hloov qhov kev xaiv multimeter hloov mus rau V2.5 volts thiab ntsuas dua, thiab sib piv ob qhov ntsuas tau (ua tib zoo nyeem cov kab ntawv teev. tom qab hloov qhov ntau).
(7) Tom qab kev ntsuas tiav, tshem tawm cov khoom siv hluav taws xob. Muab cov multimeter tso tseg raws li qhov yuav tsum tau ua tom qab siv multimeter.
