N'afọ 1881, Tesla kwagara Budapest, Hungary, ịrụ ọrụ n'okpuru Tivadar Puskás na ụlọ ọrụ telegraph, Budapest Telephone Exchange. Mgbe ọ bịarutere, Tesla ghọtara na ụlọ ọrụ ahụ, mgbe ahụ na-ewu, anaghị arụ ọrụ, ya mere ọ rụrụ ọrụ dị ka onye na-ese ihe na Central Telegraph Office. N'ime ọnwa ole na ole, Budapest Telephone Exchange ghọrọ ọrụ, e kenyekwara Tesla ọkwa onye isi ọkụ eletrik. N'oge ọrụ ya, Tesla mere ọtụtụ ndozi na Central Station ma kwuo na o meela ka onye na-emegharị ekwentị ma ọ bụ onye na-eme ka ọ dị elu, nke a na-emeghị patent ma ọ bụ kọwaa n'ihu ọha. Ajụjụ: Olee ọnọdụ Tesla kenyere na Central Telegraph Office?
onye na-ahụ maka ọkụ eletrik