subject: 5 Famous Moments of Genius [print this page] From the first time Nikola Tesla saw the demonstration of how a direct current (DC) circuit, he knew there had to be a better way. But he could never quite figure out what the suitable alternative would be. So one day he was out for a walk when it just came to him. He used his walking stick to draw a picture explaining how alternating current would work to his walking partner. Nikola developed the AC-current generation system which comprised of a motor and a transformer, making him arguably the greatest electrical engineer of all time.