He gave the world electricity and died penniless.

Tesla's Coil: The Inventor Who Lit the World and Lost Everything

Nikola Tesla patents the Tesla coil and begins the War of Currents

Nikola Tesla's AC electrical system powered the modern world, but poor business sense and eccentric obsessions left him penniless and forgotten while Edison was celebrated.

On April 10, 1891, Nikola Tesla filed the patent for his high-frequency transformer — the Tesla coil — cementing his reputation as the era's most innovative electrical engineer. The patent was one of nearly 300 he would file in his lifetime; it would also be one of his last commercially successful ones.

Tesla had already survived his greatest triumph and was approaching his greatest defeat. His alternating current (AC) electrical system had been commercially proven when George Westinghouse used it to light the 1893 Chicago World's Fair — 200,000 light bulbs, more than any city in America possessed at the time. AC's victory over Thomas Edison's direct current (DC) was essentially complete.

Yet Tesla's personal circumstances were deteriorating. His partnership with Westinghouse had produced little lasting wealth. His grand scheme for wireless electrical transmission — using the Earth itself as a conductor — consumed his resources without producing practical results. His eccentric personality and unconventional theories gradually isolated him from the mainstream scientific community.

By 1917, Tesla was nearly penniless. He paid his hotel bill with ownership rights to his later pate…

💡 Tesla claimed to have developed a working model of a 'death ray' in 1934 — a directed-energy weapon he offered to the League of Nations. No working model has ever been found.