Parece que é "Mentores". Um show canadense, mas combina com a premissa que você escreveu bem de perto. Correu por quatro temporadas de 13 episódios cada. Resumo por Wikipedia :
It was about a boy genius who uses his computer to bring famous historical figures from the past into the present. As an example, he and his girlfriend "summoned" Albert Einstein, Alexander Graham Bell, and Joan of Arc in the first three episodes. Eventually the boy hands the machine over to his two cousins who bring forward figures such as Confucius and Vlad the Impaler.