Yuav ua li cas siv ib tug multimeter los xyuas seb lub Circuit Court yog luv luv los yog grounded
Yog tias koj xav kuaj xyuas qhov luv luv hauv Circuit Court. Ua ntej, txiav tawm lub hwj huam mov mus rau kab, ces qhib lub load keyboards thiab siv lub ohm ntau yam ntawm lub multimeter los ntsuas qhov tsis kam ntawm ob lub xov hlau. Raws li ib txwm muaj, qhov kev tiv thaiv siab dua yog qhov zoo dua. Yog tias nws tau txiav txim siab seb lub Circuit Court yog grounded, lub ohm ntau ntawm multimeter tuaj yeem siv tau. Ntsuas qhov tsis kam ntawm txhua lub voj voog rau hauv av. Qhov loj dua qhov zoo. Nws yuav tsum tau muab sau tseg tias siv ib tug multimeter los ntsuas rau luv luv circuits thiab grounding nyob rau hauv ib tug Circuit Court yog tsis raug. Nws kuj tsis tsim nyog. Yog hais tias lub grounding los yog luv luv-circuit resistance yog heev me me, nws muaj peev xwm ntes tau nrog ib tug multimeter. Yog tias qhov kev tawm tsam loj dua me ntsis, nws yuav tsum tsis txhob raug kuaj pom. Lub multimeter tsis tuaj yeem ntes nws hauv qhov hluav taws xob qis ntawm 380V. Lub 500V shaker yuav tsum tau siv rau kev ntsuas, txawm hais tias ntawm kab lossis hauv av. Txhua qhov yuav tsum siab tshaj 0.38 megaohms. Txwv tsis pub, nws yog unqualified.
Tus txheej txheem ntawm kev siv ib tug multimeter los xyuas luv luv Circuit Court. Ua ntej, txiav tawm lub hwj huam mov ntawm cov kab sim. Tom qab ntawd tshem tawm ib qho kawg ntawm kev tswj transformer, qhov taw qhia lub teeb, thiab qhov hluav taws xob hloov hluav taws xob hauv Circuit Court, vim tias cov khoom no txuas ncaj qha mus rau hauv Circuit Court. Yog tias tsis tshem tawm, qhov impedance ntawm cov khoom no yuav cuam tshuam rau koj qhov ntsuas. Qee lub circuits kuj muaj peb-theem loads xws li zaus converters thiab rectifier txuas hniav, thiab cov khoom siv no yuav tsum tau txiav tawm ntawm Circuit Court. Tom qab ntawd tig lub multimeter mus rau hom diode (buzzer hom) thiab ntsuas qhov conductivity ntawm ob lub xov hlau raug kuaj.
Yog hais tias liab thiab dub probes ntawm lub multimeter sib tshooj, thiab muaj ib tug buzzing suab los yog impedance tso tawm nyob rau hauv lub multimeter, nws qhia tau hais tias muaj teeb meem nrog lub xeem Circuit Court. Nquag, tsis muaj suab nrov thiab lub vijtsam zaub ntawm multimeter tsis qhia cov lej hloov pauv. Txoj kev tshawb nrhiav hauv av rau txoj kab kuj zoo ib yam. Qhov no tsuas yog ib txoj kev tshawb nrhiav pom xwb. Txhawm rau ua kom tsis pom kev, nws yog qhov txhim khu kev ntseeg ntau dua los siv lub rooj sib tsoo rau kev tshawb pom, uas yuav tsum muaj tsawg kawg yog ntau dua 0.5 megohms.
Lub ntsiab ntawm qhov voltage yog qhov sib txawv. Ntev npaum li qhov voltage ntawm ob kab yog 0, nws tuaj yeem ntsuas tau siv hom kev tiv thaiv:
1. Piv txwv tias muaj qhov luv luv ntawm kab A thiab kab B yuav tsum ntsuas, tej zaum yuav muaj qhov hluav taws xob (xws li 220 volts) ntawm kab A thiab kab B mus rau kab nruab nrab, thiab qhov muaj peev xwm ntawm lawv cov kab muaj peev xwm A thiab Muaj peev xwm B. Ntau tus neeg ua ntej xav tias yog lawv ntsuas ncaj qha rau hauv hom kev tiv thaiv, lawv yuav tsum tau txiav lub hwj chim ntawm kab A thiab kab B cais ua ntej ntsuas. Lub tswv yim no tsis yog qhov yuam kev, tab sis yog kev saib xyuas.
2. ncaj qha teeb lub multimeter mus rau AC voltage ntau, xaiv qhov siab tshaj plaws, xws li AC1000 volts, thiab tom qab ntawd siv AC voltage ntau ntawm multimeter los ntsuas kab A thiab kab B. Yog tias muaj qhov hluav taws xob tsawg (xws li 200 volts) nruab nrab ntawm ob kab, nws tuaj yeem ua pov thawj tias muaj peev xwm A thiab muaj peev xwm B tsis sib npaug, uas yog, muaj qhov sib txawv ntawm qhov muaj peev xwm A thiab muaj peev xwm B. Ob kab no tsis sib npaug thiab tsis luv luv ua ke.
3. Yog tias tsis muaj qhov ntsuas hluav taws xob nruab nrab ntawm kab A thiab kab B siv AC qhov hluav taws xob ntau, rau qhov kev lees paub, DC voltage ntau yam xws li 1000 volts tuaj yeem xaiv los ntsuas nruab nrab ntawm lawv, thiab nws tuaj yeem paub tseeb tias tsis muaj DC voltage. Qhov no tuaj yeem ua pov thawj tias muaj peev xwm A thiab muaj peev xwm B sib npaug. Nco ntsoov tias kev sib npaug tsis txhais hais tias lawv tsis muaj qhov hluav taws xob ntawm cov kab nruab nrab N. Piv txwv li, ob kab A thiab kab B muaj qhov hluav taws xob ntawm 220 volts ntawm cov kab nruab nrab N, tab sis qhov voltage ntawm lawv kuj yog 0 volts. Nyob rau lub sijhawm no, qhov tsawg tshaj plaws kuj tuaj yeem siv los ntsuas qhov kev tawm tsam ntawm ob kab no. Yog tias nws nyob ze rau 0 ohms, nws txhais tau hais tias ob kab no luv luv ua ke.
4. Raws li seb qhov ntsuas yog hauv av, txoj kev saum toj no kuj siv tau rau kev ntsuas yooj yim. Lub tswv yim yog kom nkag siab txog av xaim raws li cov xaim tsis tu ncua. Tab sis feem ntau, txhawm rau ntsuas seb nws kov hauv av, lub megohmmeter tuaj yeem siv los ntsuas qhov kev tiv thaiv hluav taws xob (feem ntau 5 megohms rau rwb thaiv tsev), thiab lub sijhawm no, lub zog hluav taws xob yuav tsum tau ntsuas.
