Nta ntawm Digital Multimeter thiab Dual Impedance Digital Multimeter
Lub hauv paus muaj pes tsawg leeg ntawm ib qho yooj yim digital multimeter yog qhia hauv daim duab. Muab ob npaug rau A / D converter yog lub "lub siab" ntawm cov multimeter digital, los ntawm cov analogue - digital conversion. Peripheral circuits feem ntau suav nrog kev hloov pauv kev ua haujlwm, kev ua haujlwm thiab ntau yam xaiv hloov, LCD lossis LED zaub, ntxiv rau buzzer oscillator circuit, tsav Circuit Court, nrhiav kom pom kab ntawm thiab tawm Circuit Court, qhov ntsuas hluav taws xob qis qis, tus lej lej thiab kos npe (polarity kos npe, thiab lwm yam.) .) tsav Circuit Court.
A/D converter yog lub hauv paus ntawm cov digital multimeter, siv lub monolithic loj-scale integrated circuits 7106. 7106 siv lub sab hauv heterodyne rooj tso zis, muaj peev xwm tsav lub LCD zaub, lub hwj chim noj yog tsis tshua muaj heev. Nws cov yam ntxwv tseem ceeb yog: ib qho hluav taws xob ib leeg, thiab ntau qhov voltages, kev siv 9V stacked roj teeb kom ua tiav cov cuab yeej siv me me, kev tawm tswv yim siab impedance, kev siv cov keyboards hauv analogue kom ua tiav tsis siv neeg xoom thiab polarity hloov dua siab tshiab. Qhov tsis zoo yog qhov kev hloov pauv A / D qeeb, tab sis tuaj yeem ua tau raws li cov kev xav tau ntawm cov qauv ntsuas hluav taws xob.
Basic paub txog impedance
Feem ntau ntawm cov tshuab digital multimeters muag hauv khw niaj hnub no rau kev ntsuas kev lag luam, hluav taws xob, thiab cov tshuab hluav taws xob muaj cov khoom siv hluav taws xob zoo heev, feem ntau ntau dua 1 megohm. Qhov no tsuas yog txhais tau hais tias thaum DMM ntsuas lub voj, nws yuav muaj kev cuam tshuam me me lossis tsis muaj txiaj ntsig ntawm kev ua haujlwm ntawm lub voj. Qhov no yog qhov xav tau rau kev ntsuas kev xav tau ntau, tshwj xeeb tshaj yog rau cov khoom siv hluav taws xob ntau dua los yog tswj cov voj voog. Yav dhau los siv cov cuab yeej daws teeb meem xws li analogue multimeters thiab solenoid testers feem ntau muaj qis impedance input loops ntawm ib ncig ntawm 10 kOhm lossis tsawg dua. Txawm hais tias cov cuab yeej zoo li no tsis cuam tshuam los ntawm cov hluav taws xob tsis zoo, lawv tsuas yog tsim nyog rau kev ntsuas hluav taws xob hluav taws xob lossis lwm yam kev siv uas tsis tshua muaj kev tawm tswv yim impedance yuav tsis cuam tshuam lossis hloov kev ua haujlwm ntawm lub circuit.
Muab qhov nyuaj thiab ntau haiv neeg ntawm kev ntsuas thiab ntsuas kev xav tau nyob rau hauv ntau qhov chaw niaj hnub no, dual-impedance input instrumentation muab cov teeb meem los yog cov kws tshaj lij nrog kev yooj yim dua kom tau raws li ntau yam ntawm daim ntawv thov lossis kev ntsuas kev xav tau, los ntawm qhov ntsuas hluav taws xob yooj yim mus rau teeb meem rhiab hluav taws xob circuits. Tsis tas li ntawd, lub ntsuas hluav taws xob ntsuas hluav taws xob pab txhawb kev ua haujlwm tau zoo thiab muab qhov cuam tshuam ntxiv ua ntej pib ua haujlwm hauv cov txee tswj lossis lwm qhov chaw uas muaj qhov hluav taws xob tam sim no.
Lub Dual Impedance Input Meter muab cov teeb meem los yog cov kws tshaj lij nrog kev hloov pauv ntau dua rau cov ntawv thov lossis kev ntsuas xws li ntsuas qhov ntsuas hluav taws xob yooj yim mus rau kev daws teeb meem hluav taws xob hluav taws xob. Ntxiv rau qhov no, lub ntsuas hluav taws xob tau tsim rau hauv lub ntsuas hluav taws xob pab txhawm rau ua kom muaj txiaj ntsig thiab ntxiv lwm qhov cuam tshuam ua ntej pib ua haujlwm hauv cov txee tswj lossis lwm qhov chaw uas muaj qhov hluav taws xob tam sim no.
