Hfe Multimeter txhais li cas?
HFE cov ntaub ntawv nyob rau hauv multimeter yog siv los ntsuas qhov tam sim no magnification ntawm lub transistor, thiab muaj cov sockets rau ntsuas lub transistor ntawm no meter. HFE cov ntaub ntawv feem ntau yog siv los ntsuas qhov ua kom muaj zog. Ua ntej kev ntsuas, nws yuav tsum tau txiav txim siab seb lub triode yog PNP lossis NPN, thiab tib lub sijhawm txiav txim siab polarity ntawm txhua tus pin.
Siv: thaum ntsuas, ntxig lub triode rau hauv cov polarity jack, thiab koj tuaj yeem nyeem qhov kev nthuav dav tam sim no ntawm triode.
Cov ntaub ntawv txuas ntxiv:
Lub 'meter' taub hau ntawm lub multimeter yog rhiab heev galvanometer. Lub dial ntawm lub taub hau ' meter ' yog luam tawm nrog ntau yam cim, zuam cim thiab tus lej muaj nuj nqis. Lub cim AV-Ω qhia tias qhov ntsuas no yog ib lub ntsuas ntsuas uas tuaj yeem ntsuas tam sim no, qhov hluav taws xob thiab tsis kam.
Muaj ntau cov kab ntawv sau rau ntawm lub xov tooj, ntawm cov uas sab xis kawg cim nrog "Ω" yog cov kab hluav taws xob tsis sib haum, nws txoj cai kawg yog xoom thiab sab laug kawg yog ∞, thiab kev faib tawm ntawm qhov ntsuas qhov tseem ceeb tsis sib npaug. Lub cim "-" lossis "DC" txhais tau tias DC, "~" lossis "AC" txhais tau tias AC, thiab "~" txhais tau hais tias cov kab ntau ntawm AC thiab DC. Ob peb kab ntawm tus lej nyob rau hauv kab kab yog qhov ntsuas qhov tseem ceeb sib xws rau cov zog sib txawv ntawm tus xaiv hloov.
Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm multimeter:
Lub hauv paus ntsiab lus ntawm multimeter yog siv lub rhiab magnetoelectric DC ammeter (microammeter) ua lub taub hau meter. Thaum ib tug me me tam sim no hla lub 'meter', yuav muaj ib tug qhia tam sim no. Tab sis lub 'meter' tsis tuaj yeem dhau qhov tam sim no loj, yog li nws yog qhov yuav tsum tau shunt lossis nqis qee cov resistors nyob rau hauv parallel thiab series ntawm lub 'meter' los ntsuas qhov tam sim no, voltage thiab tsis kam nyob rau hauv Circuit Court.
Hfe, PNP, NPN thiab npn ntawm multimeter txhais li cas?
HFE yog lub npe luv ntawm triode DC tam sim no amplification yam, uas yog tam sim no amplification yam ntawm triode; PNP thiab NPN sawv cev rau ob hom triodes.
When the triode is turned on, IE= (magnification +1)*IB has nothing to do with ICB. When ICB=0 ICB>0, there may be something wrong with the triode, so when the triode is working normally, ICB=0 regardless of whether it is working in the amplification region or the saturation region. When UEB>{{0}}.7V (silicon) (germanium 0.2V) thiab RC/Rb < magnification, lub transistor ua haujlwm hauv cheeb tsam saturation, thiab vice versa.
Qhov sib txawv ntawm PNP triode thiab NPN triode yog tias cov lus qhia ntawm ob PN junctions txawv.
PNP yog ib hom cathode, uas yog, N hlws ris ntawm ob lub PN junctions yog txuas raws li lub hauv paus, thiab lwm yam ob P junctions yog cov collector thiab emitter feem; Ib tug triode cim nrog ib tug inward xub nyob rau hauv lub Circuit Court daim duab. NPN yog qhov opposite.
Cov ntaub ntawv txuas ntxiv:
Tus naj npawb ntawm cov khoom siv digital multimeter feem ntau yog {{0}}/2 rau 8 1/2. Muaj ob lub hauv paus ntsiab lus los txiav txim siab cov lej ntawm cov cuab yeej digital: ib qho yog tias cov lej uas tuaj yeem pom txhua tus lej ntawm 0 txog 9 yog cov lej lej;
Qhov thib ob, tus lej tus nqi ntawm tus lej me me yuav siv tus lej siab tshaj plaws hauv qhov siab tshaj plaws uas pom tus nqi raws li tus lej, thiab thaum siv tag nrho qhov ntsuas, tus nqi suav yog 2000, uas qhia tau tias qhov ntsuas muaj peb tus lej lej, thaum tus lej ntawm tus lej feem ntau yog 1 thiab tus lej yog 2, yog li nws yog hu ua 3 1/2 tus lej, uas tau hais tias "peb thiab ib nrab tus lej", thiab nws qhov siab tshaj plaws tus lej tsuas tuaj yeem tso saib 0 lossis 1 (0 feem ntau tsis pom).
{{0}}/3 tus lej (hais tias "peb thiab ob peb tus lej") Tus lej siab tshaj plaws ntawm cov tshuab ntsuas digital tsuas tuaj yeem tso saib tus lej ntawm 0 txog 2, yog li qhov siab tshaj plaws tso saib tus nqi yog 2999. Nyob rau hauv tib lub sijhawm , nws yog 50 feem pua siab tshaj qhov txwv ntawm 3 1/2 tus lej digital multimeter, thiab nws tseem ceeb heev tshwj xeeb tshaj yog rau ntsuas 380V AC voltage.
Nrov digital multimeters feem ntau yog ib tug handheld multimeters nrog 3 1/2 ntsis zaub, thiab 4 1/2 thiab 5 1/2 ntsis (tsawg dua 6 ntsis) digital multimeters muab faib ua tes - tuav thiab desktop hom. Ntau tshaj 6 1/2 tus lej feem ntau yog rau desktop digital multimeter.
