Kev ntsuas kub ceev ntawm kev tiv thaiv online nrog lub digital multimeter
Siv digital multimeter los ntsuas kev kub ntxhov hauv online. Cov ntsiab lus hauv qab no yuav tsum tau sau tseg thaum siv cov kauj ruam-down voltage ntsuas txoj kev:
(1) Kev ntsuas tag nrho ntawm qhov ntsuas hluav taws xob thiab qhov hluav taws xob qhib hluav taws xob ntawm hluav taws xob thaiv ntawm ntau hom digital multimeters txawv, yog li tus nqi ntau ntawm cov khoom thauj khoom resistor R1 yuav tsum tau txiav txim siab sim.
(2) Thaum lub sijhawm ua haujlwm, lub loading resistor R1 yuav tsum tau txuas nrog cov digital multimeter V / Ω thiab COM jack ua ntej, thiab cov multimeter digital yuav tsum nyeem qhov ntsuas qhov tseeb ntawm R1 ntawm qhov resistor ua ntej ntsuas qhov kev tiv thaiv online. Koj tsis tuaj yeem txuas lub voj voog nyob rau hauv kev sim ua ntej thiab tom qab ntawd txuas tus resistor R1 nyob rau hauv parallel. Qhov no yuav ua rau lub raj silicon hauv Circuit Court nyob rau hauv kev sim ua conductive vim lub siab hluav taws xob thaiv qhov ntsuas hluav taws xob ntawm digital multimeter, yog li poob lub ntsiab lus ntawm kev ntsuas (tsim qhov kev ntsuas loj). Yog li ntawd, qhov kev txiav txim no tsis tuaj yeem thim rov qab.
(3) Txij li thaum tus nqi ntawm cov resistor txuas nrog nyob rau hauv parallel nrog lub emitter hlws ris thiab collector hlws ris ntawm lub transistor nyob rau hauv ib tug dav Circuit Court feem ntau yog kΩ mus rau ob peb puas kΩ, thiab muaj tsawg heev kaum ohms, yog li thaum ntsuas hauv internet, lub digital multimeter feem ntau yog muab tso rau hauv nruab nrab thaiv ua ntej. , uas yog, 200kΩ thaiv (qhov kev daws teeb meem ntawm qhov thaiv no yog 0.1kΩ) lossis 20kΩ thaiv. Yog R=R1 ntsuas. Yog tias RX/(R1+RX) yog 0 lossis tsawg heev, nws txhais tau hais tias lub Circuit Court nyob rau hauv kev xeem muaj ib tug luv luv Circuit Court txhaum (RX=0) los yog ntau yam siab dhau lawm. Hauv qhov no, qhov barrier qis (2kΩ barrier) yuav tsum tau siv rau kev ntsuas kom ntxaws. Yog R=R1 ntsuas. Yog tias RX/(R1+RX) nyob ze heev rau R1, nws txhais tau hais tias lub Circuit Court nyob rau hauv kev sim yuav muaj ib tug qhib Circuit Court txhaum (RX=∞) los yog ntau yam yog tsawg, thiab lub siab thaiv. (2WΩ thaiv) yuav tsum tau siv rau kev rov kuaj dua.
(4) 200Ω hluav taws xob thaiv thiab 20MΩ barrier feem ntau tsis tshua siv hauv kev ntsuas hauv online. Vim tias qhov chaw thau khoom resistor R1 txuas nrog rau qhov sib npaug nrog qhov ntsuas qhov ntsuas RX, qhov ntsuas qhov ntsuas hluav taws xob tau nthuav dav thiab muaj peev xwm ntsuas qhov ntsuas siab tau raug txhim kho. Yog li, feem ntau siv 2MΩ barrier yog txaus. Tsis tas li ntawd, txij li qhov kev daws teeb meem ntawm 2kΩ thaiv yog 1Ω, nws yog qhov txaus los siv qhov thaiv no los txiav txim seb puas muaj kev puas tsuaj luv luv hauv online transistor uas raug txiav tawm ntawm lub voj voog. Feem ntau hais lus, tsis tsuas yog peb qhov chaw thau khoom tuaj yeem ua tau raws li qhov xav tau ntawm kev ntsuas kev tiv thaiv online. Siv lub DT830A digital multimeter ua piv txwv, 2kΩ thaiv yog R1=R0=1kΩ, 200kΩ thaiv yog R1=0.47RO=47kΩ, thiab 2MΩ thaiv yog R1=0.47R{19}}kΩ. Tau kawg, peb kuj tuaj yeem siv 470kΩ potentiometer los hloov cov saum toj no peb qhov chaw thau khoom.
(5) Tom qab ntsuas qhov kev tiv thaiv hauv online, nco ntsoov tshem tawm tam sim ntawd tshem tawm cov khoom tiv thaiv R1 txuas ntawm digital multimeter V / Ω thiab COM jack kom tsis txhob cuam tshuam rau kev siv ib txwm siv ntawm multimeter thiab ua rau muaj xwm txheej (thaum ntsuas hluav taws xob siab).
