Dielectric ndi chotchingira magetsi chomwe chimalekanitsa mbale ziwiri kapena mapepala a kondakitala pa capacitor. Zotchingira magetsi ndi zinthu zomwe sizingathe kuyendetsa magetsi, mwachitsanzo, pulasitiki, galasi, pepala, kapena matabwa. Ntchito ya dielectric ndikuwonjezera mphamvu kuti capacitor isunge mphamvu zambiri zamagetsi komanso mphamvu zamagetsi.
Capacitor ingagwire ntchito ngati ma conductor plate onse awiri sakukhudzana kotero kuti chaji yamagetsi isasunthe kuchokera pa conductor imodzi kupita ku ina. Momwemonso, kuti chaji yamagetsi isasunthe kuchokera pa conductor kupita ku mpweya, malo pakati pa ma conductor awiriwa ayenera kukhala vacuum. Pankhani yokhudza parallel plate, capacitor yakambidwa za capacitance ya ma parallel plate capacitors omwe amalekanitsidwa ndi vacuum. Capacitance ya capacitor mu vacuum ili ndi zoletsa kotero kuti kuti muwonjezere capacitance, ikani dielectric pakati pa ma plate awiriwa.
Dielectric imawonjezera mphamvu yamagetsi chifukwa mphamvu yamagetsi pakati pa mbale ziwiri zoyendetsera magetsi imachepa
N’chifukwa chiyani mphamvu ya capacitor imawonjezeka dielectric ikayikidwa pakati pa mbale ziwiri kapena mapepala? Kuti mupeze yankho la funsoli, choyamba, kumbukirani phunziro lokhudza mphamvu yamagetsi. Monga momwe mphamvu yamagetsi imakokerana, pomwe mosiyana ndi mphamvu yamagetsi imakokerana. Mwachitsanzo, mphamvu yabwino imakokera mphamvu yoipa koma imakokera mphamvu yabwino. Nanga n’chifukwa chiyani mapulasitiki omwe ali ndi mphamvu yoipa amakoka mapepala ang’onoang’ono omwe sali ndi mphamvu yamagetsi? Izi zimachitika chifukwa pepalalo limakumana ndi mphamvu yogawa mphamvu.
Ma electron mu zinthu zotetezera kutentha monga pepala sangathe kuyenda momasuka ngati ma electron mu zinthu zoyendetsera magetsi. Choncho, pulasitiki yomwe ili ndi mphamvu yoipa ikayandikira pepala, ma electron omwe amamangiriridwa ku atomu amakanidwa kutali ndi pulasitiki yomwe ili ndi mphamvu yoipa. Kotero kuti pamakhala kugawanika kwa mphamvu yoipa ndi mphamvu yoipa pa pepala. Mphamvu yoipa pa pepala ili kutali ndi pulasitiki, pomwe mphamvu yoipa pa pepala ili ndi mtunda woyandikira pulasitiki. Kenako, mphamvu yoipa pa pulasitiki imakoka mphamvu yoipa pa pepala mpaka pepalalo litayandikira pulasitiki.
Njira yolumikizira mphamvu ya magetsi yomwe imachitika pa mapepala ndi yofanana ndi kusinthasintha mphamvu ya magetsi yomwe imachitika mu dielectric. Mwachitsanzo, monga momwe chithunzi chili kumanzere chikusonyezera, poyamba panali ma conductor awiri okha omwe ali ndi magetsi. Mbale yakumanzere ili ndi magetsi abwino pomwe mbale yakumanja ili ndi magetsi oipa kotero kuti malo olowera magetsi akuchokera kumanzere kupita kumanja.
Pambuyo poti dielectric yayikidwa pakati pa mbale ziwiri za conductor, positive charge pa mbale yakumanzere imakoka ma electric pamwamba pa dielectric yapafupi. Komanso, negative charge pa mbale yakumanja imathamangitsa ma electric pamwamba pa dielectric yapafupi. Ma electric mu dielectric, omwe ndi insulator, samasuka kuyenda ngati ma electric mu conductor. Chifukwa chake, ma electric amakhalabe omangika ku atomu, koma pali polarization ya ma electric omwe ali ndi negative charge ndi ma proton omwe ali ndi positive charge, monga momwe zasonyezedwera pachithunzichi.
Kupezeka kwa mphamvu yoyipa mbali yakumanja ya maatomu a dielectric ndi mphamvu yoyipa mbali yakumanzere ya maatomu a dielectric kumabweretsa mphamvu yamagetsi. Yomwe imachokera kumanja kupita kumanzere, zomwe zimafooketsa mphamvu yamagetsi yopangidwa ndi mphamvu yamagetsi pa mbale ya conductor, yomwe imachokera kumanzere kupita kumanja. Chifukwa chake, mphamvu yamagetsi imachepa osati chifukwa mphamvu yamagetsi pa mbale/mapepala awiri a conductor imachepa, koma chifukwa mphamvu yamagetsi imawonekera mu dielectric mbali ina. Ngati dielectric yatulutsidwa, mphamvu yamagetsi yopangidwa ndi mphamvu yamagetsi pa mbale ziwiri kapena mapepala a conductor imabwerera mwakale.
If
Mphamvu yamagetsi yopangidwa ndi mphamvu yamagetsi pa mbale zonse ziwiri za conductor imachepa, mphamvu yamagetsi pakati pa mbale ziwiri za conductor imachepanso. Chifukwa mphamvu yamagetsi imafanana mwachindunji ndi mphamvu yamagetsi monga momwe zanenedwera mu equation E = V / d, pomwe E = mphamvu yamagetsi, V = mphamvu yamagetsi ndi d = mtunda pakati pa mbale ziwiri. Ngati pasanakhale mphamvu yamagetsi ku dielectric ndi Vo ndiye kuti pambuyo pa dielectric, mphamvu yamagetsi imachepetsedwa kufika pa V ndi factor K.
Mwa masamu, Vo = KV kapena V = Vo / K kapena K = Vo / V, komwe K = chosasintha cha dielectric. Vo> V kotero kuti K> 1.
Chonde dziwani kuti kuchuluka kwa mphamvu yamagetsi pa mbale zonse ziwiri kapena mapepala a ma conductors sikusintha kotero kuti kuchuluka kwa mphamvu yomaliza kukhala yofanana ndi kuchuluka kwa mphamvu yoyambirira (Q = Qo). Kusintha kwa mphamvu ya capacitor kumawerengedwa motere:
C = capacitance yomaliza, Co = capacitance yoyambirira, Q = chaji yomaliza, Qo = chaji yoyambirira, V = chaji yomaliza, Vo = chaji yoyambirira, K = chokhazikika cha dielectric
Kutengera ndi equation yomwe ili pamwambapa, zatsimikiziridwa kuti capacitance yoyamba (Co) ndi yaying'ono pomwe capacitance yomaliza (C) ndi yayikulu. Capacitance imawonjezeka ndi factor ya K, pomwe K ndiye dielectric constant. Mtengo wa dielectric constant wa chinthu chilichonse chotetezera umasiyana. Dielectric constant (K) ndi zotsatira za chiŵerengero cha capacitance ya capacitor pogwiritsa ntchito dielectric, ndi capacitance ya capacitor pamene sakugwiritsa ntchito dielectric.
Mphamvu ya dielectric imawonjezeka chifukwa mtunda pakati pa mbale ziwiri zoyendetsera umachepa
Ntchito ina ya dielectric ndikuchepetsa mtunda (d) pakati pa mbale ziwiri za conductor. Kuti mphamvu yamagetsi (E) ndi mphamvu yamagetsi (V) pakati pa mbale ziwiri kapena mapepala a conductor ziwonjezeke, monga momwe zanenedwera mu equation E = V / d. Ngati mphamvu yamagetsi ndi mphamvu yamagetsi pakati pa mbale ziwiri kapena mapepala ziwonjezeke, ndiye kuti mphamvu ya capacitor imawonjezeka.
Ngati ma capacitor omwe akukambidwa ali ofanana, capacitance imawerengedwa pogwiritsa ntchito njira iyi:
Kutengera njira ziwiri zomwe zili pamwambapa, zitha kutsimikizika kuti capacitance (C) ya ma capacitor a mbale yofanana ikhoza kukulitsidwa mwa kuchepetsa mtunda pakati pa mbale ziwiri kapena mapepala oyendetsera (d).
Mphamvu ya dielectric imawonjezeka chifukwa mphamvu ya capacitor imawonjezeka.
Dielectric imapangidwa ndi zinthu zotetezera kutentha zomwe, ngati zili mu gawo lamagetsi lamphamvu, zidzawonongeka. Kuwonongeka kwa dielectric kumachitika pamene gawo lamagetsi lili lamphamvu kwambiri moti limatha kusuntha ma electric kuchokera mu atomu, kenako ma electric amagunda ma electric pa ma atomu ena kotero kuti kuyenda kwa ma electric mu dielectric kumachitika. Mwanjira ina, kuwonongeka kwa dielectric kumapangitsa dielectric yomwe ndi insulator yamagetsi kusanduka kondakitala yamagetsi.
Pofuna kupewa kuwonongeka, dielectric iliyonse yopangidwa kuchokera ku chinthu china chotetezera kutentha imakhala ndi mphamvu yayikulu yamagetsi yomwe ingagwiridwe, yotchedwa mphamvu ya dielectric. Mphamvu ya dielectric ya chinthu chotetezera kutentha ndi yayikulu kuposa mphamvu ya dielectric ya mpweya ndipo chinthu chilichonse chotetezera kutentha chili ndi mphamvu yosiyana ya dielectric, zina zimakhala zazing'ono ndipo zina zimakhala zazikulu. Chifukwa chake ngati dielectric yomwe ili ndi mphamvu yayikulu ya dielectric ikugwiritsidwa ntchito, mphamvu yamagetsi yomwe ingagwiridwe imakhala yayikulu ndipo mphamvu yamagetsi yomwe ingagwiridwe nayonso ndi yayikulu. Ngati mphamvu yamagetsi ndi mphamvu yamagetsi yopangidwa ndi mbale ziwiri kapena mapepala a conductor ndi yayikulu, mphamvu yamagetsi yomwe ingagwiridwe ndi conductor plate ndi yayikulu. Mphamvu yamagetsi yomwe ili mkati mwa conductor plate, mphamvu ya capacitor imakula.
