Ama-transformer ohlobo lweShell asebenzisa i-anti-ukuphakama ikhoyili enamandla aphezulu e-dielectric ukumelana nethonya lokushaya kwenhliziyo voltage. Njengoba ama-shell-type transformers asebenzisa amakhoyili anendawo enkulu, i-capacitance yochungechunge phakathi kwamakhoyili inkulu. Lapho a ukuphakama isetshenziswa, ingasabalalisa i voltage ngokufanelekile, ikhoyili yokuhlinzwa iwukuzungeza okungashintshi, okungacindezela i-voltage oscillation ebangelwa i-pulse voltage.