Hoʻohui ʻo EFD transformer core i ka palahalaha loa me ka mana-density throughput kiʻekiʻe loa no nā alapine a hiki i 1MHz a kiʻekiʻe. ʻO kēlā me kēia mea hoʻololi, e pili ana i ka laulā EFD, he haʻahaʻa ke kiʻekiʻe o ka hale ma mua o nā hoʻolālā haʻahaʻa haʻahaʻa e kū nei me ka leo magnetic like.