Electric capacitor yog ib qho khoom siv passive uas tuaj yeem khaws thiab khaws cov hluav taws xob hluav taws xob. Nws muaj ob daim hlau conductive sib cais los ntawm cov khoom siv dielectric. Daim ntawv thov ntawm hluav taws xob muaj peev xwm ntawm cov cim sib txawv rau cov phaj conductive ua rau kom tau txais ib qho nqi los ntawm lawv, uas yog qhov zoo ntawm ib phaj thiab tsis zoo rau lwm qhov. Hauv qhov no, tus nqi tag nrho yog xoom.
Kab lus no tham txog cov teeb meem ntawm keeb kwm thiab lub ntsiab lus ntawm lub capacitance ntawm lub capacitor.
Invention Story
Lub Kaum Hli 1745, tus kws tshawb fawb German Ewald Georg von Kleist pom tias tus nqi hluav taws xob tuaj yeem khaws cia yog tias lub tshuab hluav taws xob electrostatic thiab qee cov dej hauv lub khob iav txuas nrog cable. Nyob rau hauv qhov kev sim no, von Kleist tes thiab dej yog conductors, thiab iav hlab yog ib qho hluav taws xob insulator. Tom qab tus kws tshawb fawb tau kov cov hlau xaim nrog nws txhais tes, muaj qhov tso tawm muaj zog, uas yogmuaj zog ntau dua li qhov tso tawm ntawm lub tshuab hluav taws xob electrostatic. Vim li ntawd, von Kleist xaus lus tias muaj hluav taws xob khaws cia.
Xyoo 1746, Dutch physicist Pieter van Muschenbroek tau tsim lub capacitor, uas nws hu ua Leiden lub raj mis hauv kev hwm ntawm Leiden University qhov chaw uas tus kws tshawb fawb ua haujlwm. Daniel Gralat tom qab ntawd nce lub capacitance ntawm lub capacitor los ntawm kev txuas ob peb lub raj mis Leiden.
Xyoo 1749, Benjamin Franklin tau tshawb xyuas Leyden capacitor thiab tuaj txog qhov xaus tias cov nqi hluav taws xob khaws cia tsis nyob hauv dej, raws li tau ntseeg ua ntej, tab sis ntawm ciam teb ntawm dej thiab iav. Ua tsaug rau Franklin qhov kev tshawb pom, Leyden fwj tau tsim los ntawm kev npog sab hauv thiab sab nraud ntawm cov hlab iav nrog cov hlau phaj.
Industry Development
Lo lus "capacitor" yog coined los ntawm Alessandro Volta nyob rau hauv 1782. Thaum xub thawj, cov ntaub ntawv xws li iav, porcelain, mica thiab daim ntawv dawb tau siv los ua hluav taws xob capacitor insulators. Yog li, tus kws tshaj lij hauv xov tooj cua Guglielmo Marconi tau siv cov porcelain capacitors rau nws cov transmitters, thiab rau receivers - me me capacitors nrog ib tug mica insulator, uas tau tsim nyob rau hauv 1909 - ua ntej Ntiaj Teb Tsov Rog II, lawv muaj ntau tshaj plaws nyob rau hauv Teb Chaws Asmeskas.
thawj electrolytic capacitor tau tsim nyob rau hauv 1896 thiab yog ib qho electrolyte nrog txhuas electrodes. Kev loj hlob sai ntawm cov khoom siv hluav taws xob tau pib tsuas yog tom qab qhov kev tsim tawm hauv xyoo 1950 ntawm cov khoom me me tantalum capacitor nrogkhoom electrolyte.
Thaum Tsov Rog Thoob Ntiaj Teb thib Ob, raws li kev txhim kho ntawm plastics chemistry, capacitors pib tshwm sim, uas lub luag haujlwm ntawm cov insulator tau muab rau nyias cov yeeb yaj kiab polymer.
Thaum kawg, hauv 50-60s, kev lag luam ntawm supercapacitors tsim, uas muaj ntau qhov chaw ua haujlwm, vim tias qhov hluav taws xob muaj peev xwm ntawm capacitors nce 3 qhov kev txiav txim siab piv rau nws tus nqi rau cov pa roj carbon monoxide.
Lub tswvyim ntawm lub peev xwm ntawm lub capacitor
Cov nqi hluav taws xob khaws cia hauv lub phaj capacitor yog proportional rau qhov voltage ntawm lub tshuab hluav taws xob uas muaj nyob nruab nrab ntawm daim phiaj ntawm lub cuab yeej. Nyob rau hauv cov ntaub ntawv no, lub coefficient ntawm proportionality yog hu ua hluav taws xob capacitance ntawm lub tiaj tus capacitor. Hauv SI (International System of Units), hluav taws xob muaj peev xwm, raws li lub cev muaj nuj nqis, yog ntsuas hauv farads. Ib qho farad yog lub zog hluav taws xob ntawm lub capacitor, qhov hluav taws xob nruab nrab ntawm cov phiaj uas yog 1 volt nrog cov nqi khaws cia ntawm 1 coulomb.
Hluav taws xob muaj peev xwm ntawm 1 farad yog qhov loj, thiab hauv kev xyaum hauv hluav taws xob engineering thiab electronics, capacitors nrog capacitances ntawm qhov kev txiav txim ntawm picofarad, nanofarad thiab microfarad feem ntau yog siv. Qhov tsuas yog qhov tshwj xeeb yog supercapacitors, uas muaj cov pa roj carbon activated, uas ua rau kom muaj kev ua haujlwm ntawm lub cuab yeej. Lawv tuaj yeem ncav cuag ntau txhiab tus farads thiab tau siv los ua lub zog qauv hluav taws xob tsheb.
Vim li no, lub capacitance ntawm lub capacitor yog: C=Q1/(V1-V2). Ntawm no C-hluav taws xob muaj peev xwm, Q1 - hluav taws xob khaws cia hauv ib lub phaj ntawm lub capacitor, V1-V2- qhov txawv ntawm qhov hluav taws xob muaj peev xwm ntawm daim hlau.
Cov mis rau lub capacitance ntawm lub tiaj tus capacitor yog: C=e0eS/d. Ntawm no e0thiab e yog universal dielectric tas li thiab dielectric tas li ntawm cov khoom insulator S yog thaj tsam ntawm daim hlau, d yog qhov kev ncua deb ntawm daim hlau. Cov qauv no tso cai rau koj kom nkag siab tias lub peev xwm ntawm lub capacitor yuav hloov pauv li cas yog tias koj hloov cov khoom ntawm cov insulator, qhov kev ncua deb ntawm daim hlau lossis lawv cheeb tsam.
Hom siv dielectrics
Rau qhov tsim cov capacitor, ntau hom dielectrics yog siv. Qhov nrov tshaj plaws yog cov hauv qab no:
- Air. Cov capacitors no yog ob daim hlau ntawm cov khoom siv hluav taws xob, uas tau sib cais los ntawm ib txheej ntawm huab cua thiab muab tso rau hauv ib lub khob iav. Lub peev xwm hluav taws xob ntawm cov cua capacitors yog me me. Lawv feem ntau yog siv hauv xov tooj cua engineering.
- Mica. Cov khoom ntawm mica (lub peev xwm los cais ua cov ntawv nyias thiab tiv taus qhov kub thiab txias) yog tsim rau nws siv raws li insulators hauv capacitors.
- Paper. Waxed los yog varnished ntawv yog siv los tiv thaiv kom tsis txhob ntub.
Khawv zog
Raws li qhov muaj peev xwm sib txawv ntawm daim phiaj ntawm lub capacitor nce, cov cuab yeej khaws hluav taws xob vimmuaj qhov hluav taws xob hauv nws. Yog tias qhov sib txawv ntawm cov phaj txo qis, ces lub capacitor raug tso tawm, muab lub zog rau hluav taws xob Circuit Court.
Kev ua lej, cov hluav taws xob hluav taws xob uas khaws cia rau hauv hom arbitrary capacitor tuaj yeem qhia los ntawm cov qauv hauv qab no: E=½C(V2-V 1)2, qhov twg V2 thiab V1 yog qhov kawg thiab pib kev nyuaj siab ntawm daim phiaj.
Yog hais tias lub capacitor txuas nrog lub tshuab hluav taws xob nrog lub resistor thiab qee qhov ntawm cov hluav taws xob tam sim no, ces tam sim no yuav ntws los ntawm Circuit Court thiab lub capacitor yuav pib them. Thaum nws tau them tag nrho, cov hluav taws xob tam sim no hauv Circuit Court yuav nres.
Yog hais tias tus nqi them capacitor txuas nrog rau qhov sib npaug nrog lub resistor, ces tam sim no yuav ntws los ntawm ib phaj mus rau lwm qhov los ntawm tus resistor, uas yuav txuas ntxiv mus txog thaum lub cuab yeej tawm tag. Nyob rau hauv rooj plaub no, cov kev taw qhia ntawm cov paug tawm tam sim no yuav rov qab rau cov kev taw qhia ntawm cov hluav taws xob tam sim no thaum lub cuab yeej raug them.
Them thiab tso tawm lub capacitor ua raws li lub sijhawm exponential dependence. Piv txwv li, qhov hluav taws xob nruab nrab ntawm daim hlau ntawm lub capacitor thaum nws tso tawm hloov pauv raws li cov qauv hauv qab no: V(t)=Vie-t/(RC) , qhov twg V i - pib qhov hluav taws xob ntawm lub capacitor, R - hluav taws xob tiv thaiv hauv Circuit Court, t - lub sijhawm tawm.
Kev sib txuas hauv hluav taws xob hluav taws xob
txhawm rau txiav txim siab lub peev xwm ntawm cov capacitors uas muaj nyob hauvhluav taws xob Circuit Court, nws yuav tsum nco ntsoov tias lawv tuaj yeem ua ke hauv ob txoj kev sib txawv:
- Serial txuas: 1/Cs =1/C1+1/C2+ …+1/C.
- Parallel connection: Cs =C1+C2+…+C
Cs - tag nrho capacitance ntawm n capacitors. Tag nrho cov hluav taws xob capacitance ntawm capacitors yog txiav txim los ntawm cov qauv zoo ib yam li lej qhia rau tag nrho cov hluav taws xob tsis kam, tsuas yog cov qauv rau kev sib txuas ntawm cov cuab yeej siv tau rau kev sib txuas ntawm cov resistors thiab rov ua dua.
