In 1885 the ZBD model alternating-current transformer was invented by three Hungarian engineers: Ottó Bláthy, Miksa Déri and Károly Zipernowsky.
Pada 1885 model transformator alternating current ZBD diciptakan oleh tiga insinyur Hongaria: Ottó Bláthy, Miksa Déri dan Károly Zipernowsky.