Dab tsi yuav yog vim li cas rau cov ntaub ntawv tsis sib haum ntawm cov tshuab multimeter?
Yog hais tias lub zog tiv thaiv ntawm lub tshuab multimeter, uas yog, tus pointer multimeter, puas thiab lwm yam iav tuaj yeem raug kuaj ib txwm, nws txhais tau hais tias lub taub hau meter yuav tsum tsis txhob cuam tshuam. Raws li lub hauv paus ntsiab lus ntawm kev xeem ntawm multimeter kuj, nws yog feem ntau yuav hais tias lub shunt thiab voltage faib precision resistor yog burnt tawm los yog tus nqi kuj hloov. Qhov feem ntau yuav yog vim li cas rau kev puas tsuaj ntawm cov ntaub ntawv tiv thaiv ntawm cov tshuab multimeter yog coj cov ntaub ntawv tiv thaiv raws li cov ntaub ntawv hluav taws xob los ntsuas qhov voltage. Yog li ntawd, ua ntej txhua qhov kev sim, koj yuav tsum tau siv los saib seb lub iav puas raug xaiv raug thiab txhim kho tus cwj pwm zoo.
Pointer multimeter's hluav taws xob thaiv yog tawg, thiab lwm yam iav siv tau, uas qhia tau hais tias lub taub hau ntawm multimeter yog qhov zoo. Qhov no yog tshwm sim los ntawm kev siv tsis raug. Muaj ob qho laj thawj rau qhov no. Ib qho yog los ntsuas ntau qhov kev tiv thaiv kab mob ntawm AC220V voltage burning tam sim no thaiv thaum nws rub tawm ntawm DC tam sim no thaiv (tsis muaj teeb meem dab tsi tus qauv ntawm pointer multimeter, lawv yog tag nrho cov hlau-qhov txhab tiv thaiv, tag nrho cov uas yog qhov txhab nrog cov kab hluav taws xob tsis tu ncua, thiab qhov tseem ceeb ntawm kev tiv thaiv tsawg heev, piv txwv li, muaj plaub qhov kev tawm tsam hauv MF-47 nrog rau qhov tseem ceeb ntawm 0.54Ω 5.4Ω 54Ω 540Ω feem). Txawm li cas los xij, tus tswv tau hais tias lub multimeter tsuas muaj teeb meem nrog lub tshuab hluav taws xob, yog li tsis muaj teeb meem hauv cov iav no.
Qhov thib ob yog vim li cas; Rau cov pib tshiab, cov khoom siv hluav taws xob thiab hluav taws xob, tom qab siv cov ntsuas hluav taws xob thaiv hluav taws xob ntawm lub tshuab multimeter lossis kuaj xyuas lub voj voog, lawv tsis tau teeb tsa lub iav ntawm multimeter mus rau lub iav ntawm 500V AC, thiab tom qab ntawd sim AC hauv 220V AC kab lossis jack. . Muaj ntau ntau tus qauv thiab manufacturers hauv pointer multimeter. Feem ntau thiab siv dav yog cov qub 500 thiab MF-47 multimeter ua hauv Nanjing. Cia peb tsom xam thiab daws qhov teeb meem nrog MF-47.
(1) MF-47 multimeter muaj DC tam sim no iav (DCA), nrog tsib lub zog thiab 5A loj tam sim no nthuav dav, 0~0.05mA ~ 0.5 mA ~ 5mA -50mA ~ 500mA.
② Nws muaj yim feem ntau siv zog ntawm DC voltage (DCV) thiab ib qho expansion jack muaj peev xwm ntsuas DC2500V V.. 0 ~ 0.25V ~ 1V ~ 2.5V ~ 10V ~ 50V ~ 250V ~ 500V ~ 1000V ~ 2500V.
③ Muaj rau lub zog ntawm alternating tam sim no voltage (ACV), 0 ~ 10V ~ 50V ~ 250V ~ 2500.
(4) Nws cov blocks ncaj qha tam sim no (Ω) tsib lub zog. R × 1Ω R × 10Ω R × 100Ω Rx1KΩ R × 10KΩ thiab txoj kev buzzer thaum ntsuas (thaum tus nqi tsis kam yog 3 ~ 10Ω, lub buzzer yuav muab lub suab nrawm). Vim muaj qhov txwv tsis pub, lub zog ntawm transistor DC amplification factor hFE, infrared chaw taws teeb tswj teeb liab pom, suab qib DB thiab lwm yam raug tshem tawm.
Ua ntej tshaj plaws, thaum ntsuas qhov thaiv hluav taws xob, cov stylus dub tau muab tso rau hauv lub qhov → qhov tsis zoo ntawm lub ntsuas hluav taws xob lub taub hau → 20.2Ω resistor, 220.4Ω resistor thiab 2430Ω resistor, tag nrho cov uas nyob rau hauv parallel nrog lub meter taub hau. Lub sij hawm no, lub stylus liab yog muab tso rau hauv kaum-jack ntawm lub multimeter los ntawm ib tug 1A fuse → ib → 1.5V qhuav roj teeb yog kev cob cog rua nyob rau hauv series nrog ib tug resistor → ib tug 20k resistor → a → 1..7k hluav taws xob thaiv zero- teem caij sib txawv potentiometer → 500Ω resistor → lwm lub taub hau calibration R ntxiv → meter taub hau zoo ntxiv . Nws yog ib qho yooj yim to taub lub voj kaw. Raws li kev paub ntawm tus kheej, koj tuaj yeem taug qab nws.
Siv lwm multimeter los nrhiav thiab ntsuas cov kev tawm tsam no. Feem ntau, qhov kev ua txhaum no tsuas yog kub hnyiab ntawm qhov hluav taws xob thaiv txoj haujlwm uas tau rub thaum lub sijhawm ntawd. Cov resistors no tsis yog tus qauv resistors, yog li lawv tuaj yeem txuas nrog nyob rau hauv cov kab ze rau qhov puas tsuaj los yog hloov los ntawm ib qho ntawm cov khoom siv hluav taws xob tsis tu ncua qhwv ib ncig ntawm lub resistor, thiab cov xaim tsis tu ncua tuaj yeem cuam tshuam los ntawm qhov txhab hloov pauv potentiometer.
