Dielectric

Hiki i kahi capacitor ke hana inā ʻaʻole e pā nā papa ʻelua/pepa alakaʻi kekahi i kekahi i ʻole e neʻe ka uku uila mai kekahi alakaʻi a i kekahi. Pēlā nō, i ʻole e neʻe ka uku uila mai ke alakaʻi a i ka lewa, pono ka hakahaka ma waena o nā alakaʻi ʻelua i kahi vacuum. Ma ka ʻatikala e pili ana i nā capacitors papa like, ua kūkākūkā ʻia ka capacitance o kahi capacitor papa like , kahi i hoʻokaʻawale ʻia ai nā papa ʻelua e kahi vacuum. He mau palena ko ka capacitance o kahi capacitor i loko o kahi vacuum, no laila e hoʻonui i ka capacitance, ua kau ʻia kahi dielectric ma waena o nā papa ʻelua/pepa alakaʻi.

ʻO ka dielectric kahi mea hoʻokaʻawale e hoʻokaʻawale i nā papa alakaʻi ʻelua o kahi capacitor. ʻO ka insulator kahi mea hiki ʻole ke alakaʻi i ka uila, e like me ka plastic, ke aniani, ka pepa, a i ʻole ka lāʻau. ʻO ka hana o kahi dielectric ka hoʻonui ʻana i ka capacitance, e ʻae ana i ka capacitor e mālama i ka nui o ka uku uila a me ka ikehu hiki.

Hoʻonui nā dielectrics i ka capacitance no ka mea ua hoʻemi ʻia ka mana uila ma waena o nā papa alakaʻi ʻelua.

No ke aha e piʻi ai ka capacitance o kahi capacitor ma hope o ke kau ʻia ʻana o kahi dielectric ma waena o nā papa ʻelua/nā pepa alakaʻi? No ka ʻike ʻana i ka pane i kēia nīnau, e hoʻomanaʻo mua i ka haʻawina e pili ana Uila uilaE like me nā uku uila e hoʻokuke aku kekahi i kekahi ʻoiai ʻo nā uku uila ʻē aʻe e huki kekahi i kekahi. No ka laʻana, huki nā uku maikaʻi kekahi i kekahi. me ka hoʻopiʻi maikaʻi ʻole, akā e pale aku me ka hoʻopiʻi maikaʻi. A laila no ke aha e hiki ai i ka palakiko i hoʻopiʻi maikaʻi ʻole ke huki i nā ʻāpana pepa liʻiliʻi i hoʻopiʻi ʻole ʻia e ka uila? Hana ʻia kēia no ka mea ʻike nā ʻāpana pepa i ka polarization hoʻopiʻi. ʻAʻole hiki i nā electrons i loko o nā mea insulating e like me ka pepa ke neʻe manuahi e like me nā electrons i nā mea alakaʻi. No laila, ke lawe ʻia ka palakiko i hoʻopiʻi maikaʻi ʻole i nā ʻāpana pepa, e kipaku ʻia nā electrons i hoʻopaʻa ʻia i nā ʻātoma mai ka palakiko i hoʻopiʻi maikaʻi ʻole, e hopena ana i ka polarization o ka hoʻopiʻi maikaʻi ʻole a me ka hoʻopiʻi maikaʻi ma ka pepa. ʻOi aku ka mamao o ka hoʻopiʻi maikaʻi ʻole ma ka pepa mai ka palakiko, ʻoiai ʻoi aku ka kokoke o ka hoʻopiʻi maikaʻi ma ka pepa i ka palakiko. Eia kekahi, huki ka hoʻopiʻi maikaʻi ʻole ma ka palakiko i ka hoʻopiʻi maikaʻi ma nā ʻāpana pepa a hiki i ka neʻe ʻana o ka pepa māmā i ka palakiko.

ʻO ke kaʻina hana polarization, a i ʻole polarization charge, e hana ʻia ana ma kahi ʻāpana pepa ua like ia me ka polarization charge e hana ʻia ana ma kahi dielectric. E like me ka mea i hōʻike ʻia ma ke kiʻi ma ka hema, no ka laʻana, i ka wā mua he ʻelua wale nō papa alakaʻi i hoʻopiʻi ʻia i ka uila. Ua hoʻopiʻi maikaʻi ʻia ka papa hema, ʻoiai ua hoʻopiʻi maikaʻi ʻole ʻia ka papa ʻākau, no laila ke kuhikuhi o ke kahua uila mai ka hema a i ka ʻākau.

Ma hope o ke kau ʻia ʻana o ka dielectric ma waena o nā papa alakaʻi ʻelua, huki ka uku maikaʻi ma ka papa hema i nā electrons ma ka ʻili dielectric kokoke, a hoʻokuke ka uku maikaʻi ʻole ma ka papa ʻākau i nā electrons ma ka ʻili dielectric kokoke. ʻAʻole noa nā electrons i loko o ka dielectric, he insulator, e neʻe e like me nā electrons i loko o ke alakaʻi. No laila, noho paʻa nā electrons i nā ʻātoma, akā aia kahi polarization o nā electrons i hoʻopiʻi maikaʻi ʻole a me nā protons i hoʻopiʻi maikaʻi ʻia, e like me ka mea i hōʻike ʻia ma ke kiʻi. ʻO ke alo o kahi uku maikaʻi ma ka ʻaoʻao ʻākau o nā ʻātoma dielectric a me kahi uku maikaʻi ʻole ma ka ʻaoʻao hema o nā ʻātoma dielectric e hana i kahi kahua uila i kuhikuhi ʻia mai ka ʻākau a i ka hema, a laila e hoʻonāwaliwali ana i ke kahua uila i hana ʻia e ka uku uila ma ka papa alakaʻi i kuhikuhi ʻia mai ka hema a i ka ʻākau. No laila, emi ke kahua uila ʻaʻole no ka mea e emi ana ka uku uila ma nā papa ʻelua/pepa alakaʻi akā no ka mea e ʻike ʻia kahi kahua uila ma ka dielectric ma ke ʻano ʻē. Ke wehe ʻia ka dielectric, hoʻi ka ikaika o ke kahua uila i hana ʻia e ka uku uila ma nā papa ʻelua/pepa alakaʻi i kona kūlana mua.

Inā emi ka ikaika o ke kahua uila i hana ʻia e ka hoʻouku uila ma nā papa alakaʻi ʻelua, a laila emi pū ka hiki ke uila ma waena o nā papa alakaʻi ʻelua ma muli o ke kahua uila. Ua kūlike pololei ka uila me ka hiki ke uila e like me ka mea i ʻōlelo ʻia ma ka hoohalike E = V / d, kahi ʻo E = kahua uila, V = hiki ke uila a me d = mamao ma waena o nā papa ʻelua. Inā ma mua he dielectric, ʻo ka hiki ke uila ʻo V._o No laila ma hope o ka loaʻa ʻana o kahi dielectric, ua hoʻemi ʻia ka hiki ke uila i V e kahi kumu o K. Ma ke ʻano makemakika, ʻo V_o = KV a i ʻole V = V_o / K a i ʻole K = V_o / V, kahi ʻo K = dielectric constant. V_o > V i hiki ai iā K>1.
Pono e hoʻomaopopo ʻia ʻaʻole e loli ka nui o ka uku uila ma nā papa ʻelua/pepa alakaʻi i like ai ka nui hope o ka uku me ka nui mua o ka uku (Q = Q_o). Ua helu ʻia ka loli o ka capacitance o ka capacitor me ka hoʻohana ʻana i kēia ʻano hana:

Wehewehe ʻana i ke ʻano hana: C = ka capacitance hope loa, C ₌ ka capacitance mua, Q = ka hoʻopiʻi hope loa, Q ₌ ka hoʻopiʻi mua, V = ka hiki hope loa, V ₌ ka hiki mua, K = ka paʻa dielectric

Ma muli o ke kaulike ma luna, ua hoʻoholo ʻia he ʻoi aku ka liʻiliʻi o ka capacitance mua (C _o ) ʻoiai ʻoi aku ka nui o ka capacitance hope loa (C). Hoʻonui ʻia ka capacitance e kahi kumu o K, kahi ʻo K ka dielectric constant. He ʻokoʻa ka waiwai dielectric constant o kēlā me kēia mea insulating. ʻO ka dielectric constant (K) ka hopena o ka hoʻohālikelike ʻana i ka capacitance o kahi capacitor i ka wā e hoʻohana ai i kahi dielectric i ka capacitance o ka capacitor i ka wā ʻaʻole e hoʻohana i kahi dielectric.

Hoʻonui nā dielectrics i ka capacitance no ka mea ua hoʻemi ʻia ka mamao ma waena o nā papa alakaʻi ʻelua.

ʻO kekahi hana a ka dielectric, ʻo ia ka hoʻemi ʻana i ka mamao (d) ma waena o nā papa alakaʻi ʻelua i mea e hoʻonui ai ke kahua uila (E) a me ka uila uila (V) ma waena o nā papa/pepa alakaʻi ʻelua e like me ka mea i ʻōlelo ʻia e ka hoohalike E = V / d. Inā piʻi ke kahua uila a me ka uila uila ma waena o nā papa/pepa ʻelua a laila piʻi ka capacitance o ka capacitor.
Inā he pā like ka capacitor i nīnau ʻia, a laila ua helu ʻia kona capacitance me ka hoʻohana ʻana i kēia ʻano hana:

Ma muli o nā ʻano hana ʻelua ma luna, hiki ke hoʻoholo ʻia e hiki ke hoʻonui ʻia ka capacitance (C) o kahi capacitor pā like ma ka hōʻemi ʻana i ka mamao ma waena o nā papa ʻelua/pepa alakaʻi (d).

Hoʻonui nā dielectrics i ka capacitance no ka mea e hoʻonui ana ka ikaika dielectric o ka capacitor.

Hana ʻia nā Dielectrics me nā mea hoʻokaʻawale, ke kau ʻia i loko o kahi kahua uila ikaika loa, e ʻike ʻia ka haki ʻana. Hana ʻia ka haki ʻana o ka Dielectric i ka wā e ikaika loa ai ke kahua uila a hiki ke hoʻohemo ʻia nā electrons mai nā ʻātoma, kahi e kuʻi ai kēia mau electrons me nā electrons i loko o nā ʻātoma ʻē aʻe, e hana ana i ke kahe ʻana o ka electron i loko o ka dielectric. I nā huaʻōlelo ʻē aʻe, ʻo ka haki ʻana o ka dielectric ke kumu o ka dielectric, ʻo ia hoʻi kahi insulator uila, e lilo i alakaʻi uila.

I mea e pale aku ai i ka pōʻino, ʻo kēlā me kēia dielectric i hana ʻia me kahi mea insulating i loaʻa kahi waiwai kahua uila kiʻekiʻe loa e hiki ai ke kū, ʻo ia hoʻi ka ikaika dielectric. ʻOi aku ka ikaika dielectric o kahi mea insulating ma mua o ka ikaika dielectric o ka ea a ʻokoʻa ka ikaika dielectric o kēlā me kēia mea insulating, he liʻiliʻi kekahi a he nui kekahi. No laila, inā hoʻohana ʻia kahi dielectric me ka ikaika dielectric nui, ʻoi aku ka nui o ke kahua uila hiki ke paʻa a ʻoi aku ka nui o ka voltage uila hiki ke paʻa. Inā ʻoi aku ka nui o ke kahua uila a me ka voltage uila i hana ʻia e nā papa ʻelua/pepa conductor, ʻoi aku ka nui o ka uku uila e hiki ke hoʻokipa ʻia e ka papa conductor. ʻOi aku ka nui o ka uku i loko o ka papa conductor, ʻoi aku ka nui o ka capacitance o ka capacitor.