Yuav ua li cas txiav txim siab seb MOSFET puas zoo lossis phem?

Qhov thib ob: zoo daws qhov hluav taws xob theem ntawm kev sib tshuam MOSFETsLub multimeter yuav raug hu mus rau R × 100 cov ntaub ntawv, tus cwj mem liab randomly txuas nrog lub ko taw raj, tus cwj mem dub txuas nrog rau lwm lub ko taw raj, kom tus thib peb ko taw dai saum huab cua. Yog tias koj pom tias rab koob muaj me ntsis wobble, nws tau lees tias qhov thib peb ko taw rau lub rooj vag. Txhawm rau kom tau txais kev soj ntsuam tseem ceeb ntawm qhov tshwm sim tiag tiag, tab sis kuj tseem muaj hluav taws xob kev co nyob ze los yog nrog tus ntiv tes kov dai rau hauv cov pa taw, tsuas yog pom lub koob rau qhov loj deflection, uas yog, qhia tias dai ntawm cov pa taw yog lub rooj vag. , lwm ob txhais taw yog qhov chaw thiab ntws.

Distinguishing Yog vim li cas:

JFET lub tswv yim tiv thaiv yog ntau tshaj 100MΩ, thiab cov transconductance siab heev, thaum lub rooj vag lead nyob rau hauv qhov chaw magnetic teb yog yooj yim heev rau magnetically induce lub ua hauj lwm voltage cov ntaub ntawv teeb liab ntawm lub rooj vag, yog li ntawd cov yeeb nkab nyhav mus txog, los yog nyhav. yuav tsum on-off. Yog hais tias lub cev induction voltage yog tam sim ntawd ntxiv mus rau lub rooj vag, vim hais tias tus yuam sij electromagnetic cuam tshuam muaj zog, qhov teeb meem saum toj no yuav ntau thiab ntau dua. Yog hais tias lub meter koob mus rau sab laug ntawm ib tug loj deflection, sawv cev ntawm cov yeeb nkab nyhav li ntawm, ntws-qhov chaw resistor RDS expansion, ntws-qhov tam sim no tus nqi ntawm txo IDS. ntawm qhov tsis sib xws, lub 'meter' koob mus rau sab xis ntawm qhov loj deflection, qhia tias cov yeeb nkab nyhav rau ntawm-tawm, RDS ↓, IDS ↑. Txawm li cas los xij, tus 'meter' koob nyob rau qhov kawg ntawm qhov kev taw qhia ntawm deflection, yuav tsum nyob ntawm qhov zoo thiab qhov tsis zoo ntawm cov induced voltage (zoo kev taw qhia ntawm kev ua hauj lwm voltage los yog rov qab kev taw qhia ntawm kev ua hauj lwm voltage) thiab qhov chaw ua hauj lwm ntawm cov yeeb nkab steel.
Cov lus qhia:
(1) Qhov kev sim qhia tau hais tias thaum ob txhais tes yog insulated los ntawm D thiab S ncej thiab tsuas yog lub rooj vag kov, lub koob feem ntau deflected rau sab laug. Txawm li cas los xij, yog tias ob txhais tes kov txhua tus D, S-ncej, thiab nrog cov ntiv tes kov lub rooj vag, nws muaj peev xwm soj ntsuam cov koob deflection mus rau sab xis. Lub hauv paus ua rau yog lub cev ntawm ib tug xov tooj ntawm txoj hauj lwm thiab resistors ntawm lub MOSFET muaj ib tug siv point nyhuv, thiaj li hais tias nws mus rau hauv lub saturation xeev cheeb tsam.