Dab tsi yog HFE sawv cev rau ntawm multimeter
HFE ntau yam ntawm ib tug multimeter ntsuas qhov tam sim no amplification yam ntawm ib tug siv lead ua transistor, thiab hom 'meter' no muaj sockets rau ntsuas siv lead ua transistors. Cov ntaub ntawv hFE feem ntau yog siv los ntsuas qhov ua kom muaj zog ua ntej ntsuas, nws yuav tsum tau txiav txim siab seb lub transistor yog PNP lossis NPN hom thiab txiav txim siab qhov polarity ntawm txhua tus pin.
Kev Siv: Thaum ntsuas, ntxig lub transistor rau hauv qhov sib thooj polarity kom nyeem qhov tam sim no amplification yam ntawm lub transistor.
Cov ntaub ntawv txuas ntxiv:
Lub taub hau ntawm ib tug multimeter yog ib tug rhiab ammeter. Lub dial ntawm lub taub hau yog luam tawm nrog ntau yam cim, nplai cov cim, thiab cov lej muaj nuj nqis. Lub cim A - V - Ω qhia tias qhov ntsuas no yog ib lub ntsuas ntsuas uas tuaj yeem ntsuas qhov tam sim no, qhov hluav taws xob, thiab tsis kam.
Muaj ntau qhov ntsuas kab uas luam tawm ntawm lub xov tooj, nrog rau qhov ntsuas ntsuas kab cim nrog "Ω" ntawm sab xis kawg, xoom ntawm txoj cai kawg, thiab ∞ ntawm sab laug kawg. Kev faib tawm ntawm qhov ntsuas qhov ntsuas tsis sib npaug. Lub cim "-" lossis "DC" sawv cev ncaj qha tam sim no, "~" lossis "AC" sawv cev rau qhov hloov pauv tam sim no, thiab "~" sawv cev rau qhov ntsuas kab sib koom los ntawm kev hloov tam sim no thiab ncaj qha tam sim no. Ob peb kab ntawm cov lej hauv qab kab kab yog qhov ntsuas qhov tseem ceeb sib haum rau qhov sib txawv iav txoj haujlwm 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 direct tam sim no meter (microampere meter) raws li lub taub hau meter. Thaum ib qho me me tam sim no dhau los ntawm lub taub hau meter, yuav muaj qhov qhia tam sim no. Tab sis lub taub hau 'meter' tsis tuaj yeem dhau los ntawm cov tam sim no loj, yog li nws yog qhov yuav tsum tau shunt lossis txo qhov hluav taws xob los ntawm kev sib txuas qee cov resistors nyob rau hauv parallel lossis series ntawm lub taub hau 'meter', txhawm rau ntsuas qhov tam sim no, qhov hluav taws xob, thiab kev tiv thaiv hauv Circuit Court.
Yuav ua li cas hfe, PNP, NPN ntawm ib tug multimeter txhais tau tias
HFE yog cov ntawv luv rau DC tam sim no amplification yam ntawm lub transistor, uas yog tam sim no amplification yam ntawm lub transistor; PNP thiab NPN sawv cev rau ob hom transistors.
When the transistor is on, IE=(amplification factor+1) * IB and ICB are not related. When ICB=0 and ICB>0, there may be a problem with the transistor. Therefore, when the transistor is working normally, whether it is in the amplification or saturation region, ICB=0. When UEB>{{0}}.7V (silicon) (germanium 0.2V) thiab RC/RB
Qhov sib txawv ntawm PNP hom transistor thiab NPN hom transistor nyob rau hauv cov kev taw qhia tsis sib haum ntawm ob PN junctions.
PNP yog ib hom cathode, qhov twg N junctions ntawm ob PN junctions yog txuas raws li lub hauv paus electrode, thiab lwm yam ob P junctions yog siv los ua collectors thiab emitters feem; Daim duab hluav taws xob qhia tau hais tias lub transistor nrog ib tug xub tig rau sab hauv. NPN yog qhov opposite.
