Test Diodes thiab Transistors nrog Multimeter
Teem lub digital multimeter rau diode hom thiab ntsuas PN junction nrog rau kev sojntsuam. Yog hais tias nws ua nyob rau hauv pem hauv ntej kev taw qhia, tus naj npawb tso tawm yog rau pem hauv ntej voltage poob ntawm PN hlws ris.
Ua ntej, txiav txim siab lub collector thiab emitter electrodes; Ntsuas qhov hluav taws xob rau pem hauv ntej ntawm ob lub PN junctions siv lub ntsuas phoo. Lub emitter muaj qhov siab tshaj plaws voltage poob, thaum lub collector muaj qhov qis tshaj voltage poob. Thaum kuaj ob qhov kev sib txuas, yog tias qhov kev sojntsuam liab txuas nrog cov ncej, qhov kev sim transistor yog ntawm NPN hom, thiab cov kev sojntsuam liab txuas nrog lub hauv paus b. Yog tias qhov kev sojntsuam dub txuas nrog rau cov ncej, qhov kev sim transistor yog ntawm PNP hom, thiab tus ncej no yog lub hauv paus b. Tom qab lub transistor puas lawm, PN kev sib tshuam tuaj yeem muaj ob qhov xwm txheej: tawg luv luv thiab qhib Circuit Court.
Hauv kev ntsuam xyuas hluav taws xob: Hauv kev ntsuas hluav taws xob ntawm lub transistor yog ua tiav los ntawm kev sim rau pem hauv ntej thiab rov qab tsis kam ntawm PN hlws ris los txiav txim seb lub transistor puas. Cov ceg tsis kam yog ntau dua qhov kev tiv thaiv pem hauv ntej ntawm PN kev sib tshuam. Feem ntau, yuav tsum muaj qhov sib txawv tseem ceeb hauv kev ntsuas rau pem hauv ntej thiab thim rov qab, txwv tsis pub PN kev sib tshuam yuav puas. Thaum cov ceg tiv thaiv tsawg dua qhov kev tawm tsam ntawm PN junction, ceg yuav tsum raug txiav, txwv tsis pub qhov zoo ntawm transistor tsis tuaj yeem txiav txim siab.
Mechanical zeroing ntawm pointer multimeter
Ua ntej ntsuas nrog lub pointer hom multimeter, nws yog ib qho tsim nyog yuav tsum tau soj ntsuam seb tus pointer ntawm lub multimeter puas yog raws li thiab coincides nrog xoom scale kab. Yog tias nws tsis coincide, xoom kev hloov kho yuav tsum tau ua, txwv tsis pub nws yuav cuam tshuam rau kev nyeem ntawv thiab ua rau qhov ntsuas ntsuas tsis raug. Cov txheej txheem ntawm kev siv tshuab xoom yog cais ob qhov kev sojntsuam thiab siv cov ntsia hlau ncaj nraim los kho cov neeg kho tshuab zeroing ntsia hlau nyob rau hauv nruab nrab ntawm lub xov tooj kom txog thaum tus pointer coincides nrog xoom scale kab, raws li qhia hauv daim duab. Mechanical zeroing yuav tsum tau xyuam xim rau ob lub ntsiab lus hauv qab no: (1) Tsis txhob kho cov neeg kho tshuab zeroing ntsia hlau random. Ua ntej, ua tib zoo saib xyuas. Yog tias tsim nyog los kho, kho nws ib nrab ntawm lub voj voog sab laug thiab sab xis kom tus pointer rov qab mus rau xoom. (2) Kho tshuab xoom tsis tas yuav tsum tau ua txhua zaus nws siv. Nws yog ob yam sib txawv ntawm Ohm zeroing.
