Kev nthuav dav ntawm capacitance ntsuas kev ua haujlwm ntawm digital multimeter
Cov kev ceev faj
1) Nyeem phau ntawv qhia ua ntej siv kom nkag siab txog kev siv thiab kev ceev faj ntawm qhov ntsuas.
2) Cov cuab yeej yuav tsum tsis txhob muab tso rau hauv qhov chaw uas muaj qhov kub thiab txias, av noo, dej phwj tuaj, plua plav, huab cua lossis tshuaj lom neeg nrog cov khoom siv hydrochloric acid thiab alkali siab.
3) Ua tib zoo saib xyuas qhov polarity thaum txhim kho lub roj teeb lossis lub zog hluav taws xob sab nraud, thiab tsis txhob thim rov qab kev sib txuas. Lub roj teeb yuav tsum tau muab tshem tawm yog tias nws tsis siv rau lub sijhawm ntev, thiaj li tsis ua rau lub ntsuas hluav taws xob puas vim qhov xau.
4) Tsis txhob disassemble lub microphone kom tsis txhob cuam tshuam, thiab tso nws kom zoo thaum tsis siv.
5) Tsis txhob disassemble lub twj paj nruag yam tsis tau kev tso cai. Yog tias qhov ntsuas tsis zoo li qub, nws tuaj yeem xa mus rau chav kho lossis lub Hoobkas rau kev kho dua tshiab.
1. Kev ntsuas hauv online ntawm capacitance
Raws li cov khoom ntawm cov khoom sib txawv thiab cov khoom sib txawv, kev ntsuas kev ntsuas hluav taws xob tuaj yeem hloov mus rau qhov ntsuas hluav taws xob.
Lub hauv paus tseem ceeb ntawm Circuit Court CX / V txais ib qho yooj yim active RC inverse sib txawv thiab ib qho hluav taws xob Circuit Court. Lub Wen oscillator tsim ib lub sijhawm ruaj khov AC teeb liab Vr, uas zoo siab rau CX / V hloov pauv kom tau txais AC voltage V0 (V1) proportional to CX. Tom qab raug lim los ntawm kev txiav txim thib ob bandpass lim kom tshem tawm cov clutter sab nraum qhov zaus, nws yuav raug rau AC / DC kom tau txais DC tso zis voltage V proportional rau CX. Thaum lub teeb liab AC Vr excites lub CX / V Circuit Court, cov zis voltage ntawm lub inverter integrator
Ntawd yog, ntsuas lub peev xwm CX yog ncaj qha proportional rau cov zis voltage C {{0}}, yog li ua tiav CX → V hloov dua siab tshiab. Txhawm rau kom phim cov theem pib capacitance nrog 2V qib ntawm digital multimeter, qhov zaus oscillation ntawm Wentz oscillator yog xaiv raws li 400Hz, qhov zoo voltage tus nqi yog 1V, R1 yog npaum li 20k Ω, thiab C1 yog npaum li 0.1 μ F. R2 txawv ntawm 200 Ω -2k Ω -20k Ω -200k Ω -200k Ω -2M Ω, sib xws rau qhov ntsuas qhov ntsuas qhov ntsuas ntawm 20 μ F-2 μ F-200nF-20nF-2nF.
2. Ntsuas me me capacitance
Qhov feem ntau ntawm peb thiab ib nrab tus lej multimeter rau ntsuas lub peev xwm yog 2000pF txog 20 μF, thiab nws tsis muaj hwj chim los ntsuas me me capacitors hauv qab 1pF. Raws li txoj kev capacitive impedance thiab siv high-frequency signals, qhov kev ntsuas ntawm me me capacitors tuaj yeem ua tiav. Daim duab ntsuas hluav taws xob tau qhia hauv daim duab 2. CX yog qhov ntsuas qhov ntsuas, thiab Rf yog cov lus tawm tswv yim ntawm qhov rov qab theem davhlau ya nyob twg. Thaum lub input zaus ntawm sine teeb liab Vi yog f, qhov impedance nthuav tawm ntawm CX thiab qhov nce ntawm kev ua haujlwm amplifier yog: thaum A thiab Rf nyob tas li, qhov zaus ntawm sine teeb liab f yog inversely proportional rau qhov ntsuas capacitance CX. Txhawm rau ntsuas qhov ntsuas me me, siv cov teeb liab siab zaus rau kev ntsuas.
