Multimeter: Cov txheej txheem sib txawv rau ntsuas cov khoom sib txawv
Multimeters, tseem hu ua multiplexers, multimeters, triple meters, thiab multimeters, yog qhov tseem ceeb ntsuas ntsuas hauv hluav taws xob hluav taws xob thiab lwm lub tuam tsev, feem ntau tsom rau ntsuas qhov ntsuas hluav taws xob, tam sim no, thiab tsis kam. Multimeters muab faib ua pointer multimeter thiab digital multimeter raws li lawv hom zaub. Nws yog multifunctional thiab ntau yam ntsuas ntsuas. Feem ntau, multimeter tuaj yeem ntsuas DC tam sim no, DC voltage, AC tam sim no, AC voltage, tsis kam, suab qib, thiab lwm yam. Qee qhov kuj tuaj yeem ntsuas AC tam sim no, capacitance, inductance, thiab qee qhov tsis sib xws ntawm semiconductors (xws li ) thiab lwm yam.
Cov txheej txheem ntsuas (yog tias tsis tau teev tseg, xa mus rau lub rooj pointer):
1. Kev ntsuas cov hais lus, lub mloog pob ntseg, thiab lub microphones dynamic: siv R × Ntawm 1 Ω theem, yog tias ib qho kev sojntsuam txuas nrog rau ib kawg thiab lwm qhov kev sojntsuam raug kov rau lwm qhov kawg, lub suab meej thiab "nyem" yuav raug tso tawm ib txwm. . Yog tias nws tsis ua suab, nws txhais tau hais tias lub kauj tawg. Yog hais tias lub suab me me thiab ntse, nws txhais tau hais tias muaj teeb meem nrog so lub kauj thiab nws siv tsis tau.
2. Kev ntsuas lub peev xwm: Siv qhov kev tiv thaiv ntau yam, xaiv qhov tsim nyog raws li lub peev xwm, thiab xyuam xim rau kev sib txuas cov dub sojntsuam ntawm electrolytic capacitor mus rau qhov zoo electrode ntawm lub capacitor thaum ntsuas ntsuas qhov loj ntawm microwave txoj kev theem capacitor muaj peev xwm: Nws tuaj yeem txiav txim siab raws li kev paub dhau los lossis xa mus rau tus qauv capacitors ntawm tib lub peev xwm, thiab qhov siab tshaj plaws ntawm pointer oscillation. Lub capacitance uas tau hais tseg tsis tas yuav muaj qhov sib npaug ntawm tus nqi hluav taws xob, tsuav yog qhov muaj peev xwm zoo ib yam, piv txwv li, kwv yees 100 μ F / 250V capacitor tuaj yeem siv nrog 100 μ Los ntawm kev xa mus rau lub peev xwm ntawm F / 25V. , ntev npaum li qhov siab tshaj plaws ntawm lawv cov pointer oscillation yog tib yam, nws tuaj yeem xaus lus tias lub peev xwm yog tib yam Kev kwv yees lub peev xwm ntawm picosecond capacitor: R yuav tsum tau siv × 10k Ω ntau, tab sis tsuas yog ntsuas lub peev xwm siab tshaj 1000pF. Rau cov capacitors ntawm 1000pF lossis loj dua me ntsis, ntev li ntev raws li lub koob yees duab viav vias me ntsis, lub peev xwm raug txiav txim siab txaus Test rau cov dej xau ntawm lub peev xwm: Rau cov capacitors saum 1000 microf, R tuaj yeem siv ua ntej × Ceev ceev nws ntawm 10 Ω theem thiab kwv yees ua ntej lub peev xwm capacitance, ces hloov nws mus rau R × Txuas ntxiv ntsuas ntawm 1k Ω theem ib ntus, thiab ntawm qhov no, tus taw tes yuav tsum tsis txhob rov qab, tab sis yuav tsum nres ntawm lossis ze heev rau ∞, txwv tsis pub yuav muaj qhov xau. Rau qee lub sij hawm lossis oscillating capacitors hauv qab kaum ntawm microfacies (xws li oscillating capacitors hauv cov xim TV hloov cov khoom siv hluav taws xob), cov yam ntxwv ntawm cov dej xau yog siab heev, thiab lawv tsis tuaj yeem siv ntev npaum li qhov xau me ntsis. Hauv qhov no, R × Tom qab them nyiaj ntawm 1k Ω, hloov mus rau R × Txuas ntxiv ntsuas ntawm 10k Ω qib, thiab tus taw tes yuav tsum nres ntawm ∞ es tsis txhob rov qab.
3. Thaum kuaj qhov zoo ntawm diodes, transistors, thiab voltage regulators ntawm txoj kev: vim hais tias nyob rau hauv tiag tiag circuits, lub bias tsis kam ntawm transistors los yog peripheral tsis kam ntawm diodes thiab voltage regulators feem ntau kuj loj, feem ntau nyob rau hauv lub puas thiab ntau txhiab ohms. los yog saum toj no. Ua li no, peb tuaj yeem siv R ntawm multimeter × 10 Ω lossis R × Ntsuas qhov zoo ntawm PN kev sib tshuam ntawm txoj kev ntawm 1 Ω theem. Thaum ntsuas ntawm txoj kev, siv R × PN hlws ris ntsuas ntawm 10 Ω yuav tsum muaj cov yam ntxwv rau pem hauv ntej thiab thim rov qab (yog tias qhov sib txawv hauv pem hauv ntej thiab thim rov qab tsis tseem ceeb, R tuaj yeem siv hloov × 1 Ω iav rau kev ntsuas), feem ntau Kev tiv thaiv pem hauv ntej yog nyob ntawm R × Thaum ntsuas 10 Ω iav, lub koob ntsuas yuav tsum qhia nyob ib puag ncig 200 Ω, ntawm R × Thaum ntsuas ntawm 1 Ω qib, tus xov tooj yuav tsum qhia nyob ib puag ncig 30 Ω (tej zaum yuav txawv me ntsis nyob ntawm cov phenotypes sib txawv). Yog tias qhov ntsuas ntsuas tau pom tias qhov kev tiv thaiv rau pem hauv ntej yog siab dhau los yog tus nqi rov qab los kuj qis dhau, nws qhia tau tias muaj teeb meem nrog PN kev sib tshuam thiab cov yeeb nkab. Txoj kev no yog qhov tshwj xeeb tshaj yog rau kev saib xyuas, vim nws tuaj yeem txheeb xyuas cov kav dej tsis zoo thiab txawm tias pom cov kav dej uas tseem tsis tau tawg tag tab sis muaj cov yam ntxwv tsis zoo. Piv txwv li, yog tias koj siv qhov kev ua haujlwm qis los ntsuas qhov kev tiv thaiv pem hauv ntej ntawm PN hlws ris, thiab koj siv nws, siv R × Tom qab rov ua dua ntawm 1k Ω, nws tseem yuav yog qhov qub, tab sis qhov tseeb, cov yam ntxwv. ntawm cov yeeb nkab no tau deteriorated, ua rau nws tsis tuaj yeem ua haujlwm zoo lossis tsis ruaj khov.
4. Kev ntsuas kev tiv thaiv: Nws yog ib qho tseem ceeb uas yuav tau xaiv qhov tsim nyog. Thaum tus pointer qhia 1/3 txog 2/3 ntawm tag nrho, qhov ntsuas qhov tseeb yog qhov siab tshaj plaws thiab kev nyeem ntawv yog qhov tseeb tshaj plaws. Nws yuav tsum raug sau tseg tias thaum siv R × Thaum ntsuas qhov tseem ceeb ntawm qhov kev tiv thaiv loj hauv 10k tsis kam, tsis txhob rub koj cov ntiv tes ntawm ob qhov kawg ntawm qhov kev tawm tsam, vim qhov no yuav ua rau qhov ntsuas qhov ntsuas me me dhau.
5. Kev ntsuas voltage regulator diode: Tus nqi voltage regulator ntawm voltage regulator peb feem ntau siv yog feem ntau ntau dua 1.5V, thaum lub R ntawm lub pointer meter × Resistance theem qis dua 1k yog powered los ntawm 1.5V roj teeb nyob rau hauv lub 'meter', yog li R × Ib qho hluav taws xob tswj hluav taws xob nrog qhov tsis kam ntawm tsawg dua 1k zoo li lub diode thiab muaj kev ua tiav unidirectional conductivity. Tab sis R ntawm lub pointer lub rooj × 10k iav yog siv los ntawm 9V lossis 15V roj teeb, thaum siv R × Thaum ntsuas qhov ntsuas hluav taws xob nrog tus nqi hluav taws xob tsawg dua 9V lossis 15V ntawm 10k, tus nqi rov qab yuav tsis yog ∞, tab sis yuav muaj qee qhov kev tiv thaiv tus nqi, tab sis qhov kev tiv thaiv tus nqi no tseem muaj ntau dua li tus nqi tiv thaiv pem hauv ntej ntawm qhov ntsuas hluav taws xob. Nyob rau hauv txoj kev no, peb tuaj yeem kwv yees qhov zoo ntawm qhov ntsuas hluav taws xob. Txawm li cas los xij, qhov zoo voltage regulator yuav tsum muaj qhov tseeb voltage tswj tus nqi. Peb tuaj yeem kwv yees qhov kev tswj hwm tus nqi hluav taws xob li cas raws li kev ua haujlwm pib? Nws tsis yooj yim, tsuas yog nrhiav lwm lub ntsiab lus. Txoj kev yog thawj zaug tso ib lub rooj hauv R × Ntawm 10k qib, cov kev sojntsuam dub thiab liab txuas nrog lub cathode thiab anode ntawm lub voltage regulator feem. Lub sijhawm no, lub xeev ua haujlwm tiag tiag ntawm qhov ntsuas hluav taws xob yog simulated, thiab lwm lub 'meter' tau muab tso rau ntawm qhov ntsuas hluav taws xob V × 10V lossis V × Ntawm 50V (raws li qhov ntsuas hluav taws xob tus nqi), txuas cov liab thiab dub probes rau dub thiab liab probes ntawm lub 'meter' yav dhau los, thiab ntsuas qhov ntsuas voltage yog qhov tseem ceeb ntawm qhov kev tswj hwm tus nqi ntawm qhov ntsuas hluav taws xob no. Yeej, yog vim li cas hais tias 'pib' yog tias qhov kev tsis ncaj ncees tam sim no ntawm thawj 'meter' ntawm qhov ntsuas hluav taws xob yog me ntsis me dua qhov kev tsis ncaj ncees tam sim no thaum siv ib txwm siv, yog li ntsuas qhov ntsuas hluav taws xob ntsuas tus nqi yuav loj dua me ntsis, tab sis qhov sib txawv tsis tseem ceeb. . Txoj kev no tsuas yog kwv yees qhov hluav taws xob tswj lub raj uas nws qhov hluav taws xob tsawg dua qhov hluav taws xob ntawm lub roj teeb hluav taws xob siab ntawm lub ntsuas ntsuas ntsuas. Yog hais tias tus nqi hluav taws xob tswj hwm qhov ntsuas hluav taws xob siab dhau lawm, nws tsuas yog ntsuas tau siv lub zog hluav taws xob sab nraud (hauv txoj kev no, thaum xaiv lub ntsuas ntsuas ntsuas, nws zoo li siv lub roj teeb hluav taws xob siab ntawm 15V yog qhov tsim nyog tshaj. siv 9V ib).
6. Test transistor: Feem ntau peb siv R × Nyob rau hauv 1k Ω ntau yam, seb nws yog NPN lossis PNP raj, txawm tias nws yog lub zog qis, nruab nrab lub zog, lossis cov raj muaj zog, qhov sib txuas thiab cb hlws ris yuav tsum pom tib lub unidirectional. conductivity raws li lub diode, nrog infinite reverse resistance thiab ib tug pem hauv ntej kuj ntawm txog 10K. Txhawm rau kwv yees qhov zoo ntawm cov yeeb nkab yam ntxwv, yog tias tsim nyog, ntau qhov kev ntsuas yuav tsum tau ua los ntawm kev hloov cov iav tiv thaiv. Txoj kev yog teem R × Qhov zoo conduction kuj ntawm PN hlws ris ntsuas ntawm 10 Ω yog nyob ib ncig ntawm 200 Ω; Teem R × Qhov zoo thiab tsis zoo conduction kuj ntawm PN hlws ris ntsuas ntawm 1 Ω qib yog nyob ib ncig ntawm 30 Ω. (Cov ntaub ntawv saum toj no tau txais los ntawm 47 hom 'meter', thaum lwm hom 'meter' yuav txawv me ntsis. Nws raug nquahu kom sim ob peb lub raj zoo los piav qhia thiab muaj kev nkag siab meej.) Yog tias kev nyeem ntawv loj dhau, nws tuaj yeem xaus lus tias. cov yam ntxwv ntawm cov hlab ntsha tsis zoo. Koj tuaj yeem tso lub rooj hauv R × Ntsuas dua ntawm 10k Ω. Rau cov raj uas muaj qhov hluav taws xob qis dua (qhov tseem ceeb, qhov hluav taws xob tsis zoo ntawm lub transistor yog siab dua 30V), qhov rov qab tsis kam ntawm cb hlws ris yuav tsum nyob ntawm ∞, tab sis qhov rov qab tsis kam ntawm qhov sib txuas yuav yog qee qhov, thiab cov koob 'meter' yuav tsum muaj. deviate me ntsis (feem ntau tsis tshaj 1/3 ntawm tag nrho cov ntau yam, nyob ntawm seb qhov voltage kuj ntawm lub raj). Ib yam li ntawd, thaum siv R × Thaum ntsuas qhov kev tiv thaiv ntawm ec (rau NPN raj) lossis ce (rau PNP hlab) ntawm 10k Ω ntau, lub koob ntsuas yuav me ntsis deflect, tab sis qhov no tsis txhais hais tias lub raj faulty. Tab sis siv R × Thaum ntsuas qhov kev tawm tsam ntawm ce lossis ec ntawm thaj tsam qis dua 1k Ω, qhov taw qhia ntawm lub taub hau meter yuav tsum tsis kawg, txwv tsis pub yuav muaj teeb meem nrog lub raj. Nws yuav tsum raug sau tseg tias cov kev ntsuas saum toj no yog rau cov raj silicon thiab tsis siv rau cov raj germanium. Tab sis tam sim no germanium raj kuj tsawg heev. Tsis tas li ntawd, lo lus 'rov qab' yog hais txog cov kev taw qhia ntawm PN kev sib tshuam, uas yog qhov sib txawv rau NPN thiab PNP kav.
