Dielectric yog cov khoom siv lossis cov khoom siv uas xyaum tsis xa hluav taws xob tam sim no. Qhov no conductivity yog vim muaj tsawg ntawm electrons thiab ions. Cov khoom no yog tsim nyob rau hauv cov khoom uas tsis yog-conductive tsuas yog thaum kub siab ua tiav. Hais txog dab tsi dielectric yog thiab yuav tham hauv kab lus no.
Kev piav qhia
Txhua lub tshuab hluav taws xob lossis xov tooj cua, cov khoom siv hluav taws xob lossis cov hluav taws xob hluav taws xob kis tau hluav taws xob los ntawm nws tus kheej, tab sis qhov peculiarity ntawm dielectric yog tias txawm nyob rau ntawm qhov hluav taws xob siab tshaj 550 V, ib qho me me tam sim no yuav ntws hauv nws. Ib qho hluav taws xob tam sim no hauv dielectric yog qhov txav ntawm cov khoom siv hluav taws xob hauv ib qho kev taw qhia (nws tuaj yeem ua qhov zoo lossis tsis zoo).
Nyob tam sim no
Cov hluav taws xob conductivity ntawm dielectrics yog raws li:
- Absorption currents - ib tug tam sim no uas ntws nyob rau hauv ib tug dielectric ntawm ib tug tas mus li tam sim no kom txog rau thaum nws mus txog rau ib tug equilibrium lub xeev, hloov cov kev taw qhia thaum nws yog qhib thiab thaum voltage yog siv rau nws thiab thaum nws yog muab tua. Nrog alternating tam sim no, qhov nro nyob rau hauv lub dielectric yuav muaj nyob rau hauv nws txhua lub sij hawm thaum nws nyob rau hauv qhov kev txiav txim ntawm ib tug hluav taws xob teb.
- Hluav taws xob conductivity - kev txav ntawm electrons nyob rau hauv lub zog ntawm ib daim teb.
- Ionic hluav taws xob conductivity - yog qhov txav ntawm ions. Nws muaj nyob rau hauv cov tshuaj electrolyte - ntsev, acids, alkali, thiab nyob rau hauv ntau dielectrics.
- Molion hluav taws xob conductivity yog qhov txav ntawm cov khoom hu ua molions. Nws muaj nyob rau hauv colloidal systems, emulsions thiab suspensions. Qhov tshwm sim ntawm molion txav hauv qhov hluav taws xob yog hu ua electrophoresis.
Cov ntaub ntawv rwb thaiv tsev raug cais raws li lawv lub xeev ntawm kev sib sau ua ke thiab tshuaj lom neeg. Thawj yog muab faib ua khoom, kua, gaseous thiab solidifying. Los ntawm cov tshuaj lom neeg, lawv muab faib ua cov organic, inorganic thiab organoelement cov ntaub ntawv.
Hluav taws xob conductivity ntawm dielectrics los ntawm lub xeev ntawm kev sib sau:
- Hluav taws xob conductivity ntawm cov pa roj. Gaseous tshuaj muaj ib tug heev tsawg tam sim no conductivity. Nws tuaj yeem tshwm sim nyob rau hauv lub xub ntiag ntawm cov khoom pub dawb, uas tshwm sim vim muaj kev cuam tshuam ntawm sab nraud thiab sab hauv, hluav taws xob thiab ionic yam: X-ray thiab radioactive hom, kev sib tsoo ntawm cov molecules thiab cov khoom them nqi, thermal yam.
- Hluav taws xob conductivity ntawm cov kua dielectric. Dependence yam: cov qauv molecular, kub, impurities, muaj cov nqi loj ntawm electrons thiab ions. Cov hluav taws xob conductivity ntawm cov kua dielectric feem ntau nyob ntawm seb muaj cov dej noo thiab impurities. Lub conductivity ntawm hluav taws xob ntawm polar tshuaj yog tsim txawm nrog kev pab los ntawm ib tug kua nrog dissociated ions. Thaum muab piv cov polar thiab cov dej tsis muaj polar,yav tas los muaj ib tug meej kom zoo dua nyob rau hauv conductivity. Yog tias cov kua tau ntxuav ntawm impurities, qhov no yuav ua rau txo qis hauv nws cov khoom siv hluav taws xob. Nrog rau kev nce ntxiv ntawm cov khoom ua kua thiab nws qhov kub thiab txias, qhov txo qis hauv nws cov viscosity tshwm sim, ua rau muaj kev nce hauv kev txav ntawm ions.
- Tshuaj dielectrics. Lawv cov hluav taws xob conductivity yog txiav txim raws li lub zog ntawm cov nqi dielectric hais thiab impurities. Hauv thaj chaw muaj hluav taws xob muaj zog, hluav taws xob conductivity raug kuaj pom.
Lub cev muaj zog ntawm dielectrics
Thaum qhov kev tawm tsam ntawm cov khoom tsawg dua 10-5 Ohmm, lawv tuaj yeem raug ntaus nqi rau cov neeg siv khoom. Yog tias ntau tshaj 108 Ohmm - rau dielectrics. Muaj cov xwm txheej thaum lub resistivity yuav ntau zaus ntau dua li qhov tsis kam ntawm tus neeg xyuas pib. Nyob rau hauv lub ncua sij hawm 10-5-108 Ohmm muaj ib tug semiconductor. Cov khoom siv hlau yog cov khoom siv hluav taws xob zoo heev.
Los ntawm tag nrho lub sijhawm lub sijhawm, tsuas yog 25 lub ntsiab lus ntawm cov hlau tsis yog hlau, thiab 12 ntawm lawv, tej zaum, yuav muaj cov khoom ntawm ib lub semiconductor. Tab sis, ntawm chav kawm, ntxiv rau cov khoom ntawm lub rooj, muaj ntau ntau alloys, compositions los yog tshuaj compounds nrog cov cuab yeej ntawm ib tug conductor, semiconductor los yog dielectric. Raws li qhov no, nws yog ib qho nyuaj rau kos ib txoj kab nruab nrab ntawm qhov tseem ceeb ntawm ntau yam tshuaj nrog lawv cov resistances. Piv txwv li, nrog rau qhov ntsuas kub qis, lub semiconductor yuav coj zoo li dielectric.
Daim ntawv thov
Kev siv cov khoom siv tsis zoo yog qhov dav heev, vim nws yog ib qho ntawm cov qib siv feem ntaucov khoom siv hluav taws xob. Nws tau dhau los ua qhov tseeb tias lawv tuaj yeem siv tau ua tsaug rau cov khoom hauv daim ntawv nquag thiab passive.
Nyob rau hauv daim ntawv passive, cov khoom ntawm dielectrics yog siv rau hauv cov khoom siv hluav taws xob insulating.
Nyob rau hauv lawv daim ntawv nquag, lawv tau siv hauv ferroelectrics, nrog rau cov ntaub ntawv rau emitters ntawm laser technology.
YBasic dielectrics
hom hom muaj xws li:
- iav.
- Rubber.
- Oil.
- Porcelain.
- Quartz.
- Air.
- pob zeb diamond.
Asph alt.
Nyob zoo ib tsoom niam txiv kwv tij neej tsa sawv daws.
YPlastic.
Dab tsi yog kua dielectric?
Polarization ntawm hom no tshwm sim hauv qhov hluav taws xob tam sim no. Cov kua uas tsis yog-conductive yog siv rau hauv engineering rau pouring los yog impregnating cov ntaub ntawv. Muaj 3 chav kawm ntawm kua dielectrics:
Roj av yog cov viscosity tsawg thiab feem ntau tsis yog-polar. Lawv feem ntau siv hauv cov khoom siv hluav taws xob ntau: cov roj transformer, cov dej kub-voltage. Transformer roj yog tsis-polar dielectric. Cable roj tau pom daim ntawv thov nyob rau hauv impregnation ntawm insulating ntawv xov hlau nrog ib tug voltage txog li 40 kV, raws li zoo raws li cov hlau-raws li txheej nrog ib tug tam sim no ntawm ntau tshaj 120 kV. Transformer roj muaj cov qauv huv dua li cov roj capacitor. Hom dielectric no tau siv dav hauv kev tsim khoom, txawm tias tus nqi siab piv rau cov tshuaj analog thiab cov khoom siv.
Dab tsi yog hluavtaws dielectric? Tam sim no, nws raug txwv yuav luag txhua qhov chaw vim nws cov toxicity siab, vim nws yog tsim los ntawm chlorinated carbon. Cov kua dielectric raws li cov organic silicon muaj kev nyab xeeb thiab zoo ib puag ncig. Hom no tsis ua rau hlau xeb thiab muaj cov khoom ntawm hygroscopicity tsawg. Muaj cov kua dej dielectric uas muaj cov organofluorine compound uas yog tshwj xeeb tshaj yog nrov rau nws tsis-flammable, thermal zog, thiab oxidative stability.
Thiab yam kawg yog cov roj zaub. Lawv yog cov tsis muaj zog polar dielectrics, cov no suav nrog flaxseed, castor, tung, hemp. Castor roj yog rhuab heev thiab siv nyob rau hauv daim ntawv capacitors. Cov roj seem yog evaporated. evaporation nyob rau hauv lawv tsis yog tshwm sim los ntawm ntuj evaporation, tab sis los ntawm ib tug tshuaj tiv thaiv hu ua polymerization. nquag siv hauv enamels thiab xim.
Zoo kawg
Cov kab lus tau tham hauv kev nthuav dav seb lub dielectric yog dab tsi. Ntau hom thiab lawv cov khoom tau hais. Tau kawg, kom nkag siab txog qhov ua tau zoo ntawm lawv cov yam ntxwv, koj yuav tsum kawm ntu ntawm physics txog lawv qhov tob.
