Alexander Lodygin

Alexander Nikolayevich Lodygin, known after immigration to US as Alexandre de Lodyguine (; 18 October 1847 – 16 March 1923) was a Russian electrical engineer and inventor, one of inventors of the incandescent light bulb.
Alexander Nikolayevich Lodygin was born in Stenshino village, Tambov Governorate, Russian Empire. His parents were of a very old and noble family (descendants of Andrei Kobyla like Romanovs), but of very moderate means. He studied at the Tambov Cadet School (1859–1865). Then he served in the "71st Belev regiment", and in 1866–1868 studied at the Moscow Infantry School. Soon after graduation from his military school he retired from the military and worked as a worker at the Tula weapons factory.
Timeline.
He invented an incandescent light bulb before Thomas Edison, but it was not commercially profitable. The lamp with a tungsten filament is indeed the only design used now, but in 1906 they were too expensive.
Several Lodygin's ideas were implemented much later, even after his death. In 1871 Lodygin proposed an autonomous diving apparatus that consisted of a steel mask, natural rubber costume, accumulator battery and a special apparatus for electrolysis of water. The diver was supposed to breathe the oxygen-hydrogen mix obtained by electrolysis of water.
The invented diving apparatus was very similar to modern scuba equipment
His ideas for an electrical helicopter were used many years later by Igor Sikorsky.