Bayani:

Hakanan ana amfani da zoben ƙira akan kayan aikin wuta mai ƙarfi.Zoben daraja suna kama da zoben corona, amma suna kewaye da insulators maimakon madugu.Kodayake suna iya yin aiki don murkushe korona, babban manufarsu ita ce rage yuwuwar gradient tare da insulator, hana lalacewar wutar lantarki da wuri.

Ƙimar gradient (filin lantarki) a cikin insulator ba iri ɗaya ba ne, amma ya fi girma a ƙarshen babban ƙarfin lantarki.Idan aka sami isasshen ƙarfin lantarki, insulator zai rushe kuma ya fara aiki a ƙarshen.Da zarar wani sashe na insulator a karshen ya lalace ta hanyar lantarki kuma ya zama conductive, ana amfani da cikakken wutar lantarki a kan sauran tsayin da ya rage, don haka rushewar za ta ci gaba da sauri daga babban ƙarfin wutar lantarki zuwa ɗayan, kuma za a fara baƙar walƙiya.Don haka, insulators na iya tsayawa tsayin daka mai mahimmanci idan aka rage yuwuwar gradient a ƙarshen babban ƙarfin lantarki.

Zoben daraja yana kewaye ƙarshen insulator kusa da babban madubin wutar lantarki.Yana rage gradient a ƙarshe, yana haifar da ƙarin madaidaicin ƙarfin lantarki tare da insulator, yana ba da damar gajeriyar insulator mai rahusa don amfani da wutar lantarki da aka bayar.Har ila yau, zobe masu daraja suna rage tsufa da lalacewar insulator wanda zai iya faruwa a ƙarshen HV saboda yawan wutar lantarki a can.