A Tesla coil is an electrical resonant transformer circuit invented by Nikola Tesla around 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla coils produce higher current than the other source of high-voltage discharges, electrostatic machines. Tesla experimented with a number of different configurations and they consist of two, or sometimes three, coupled resonant electric circuits.
Nikola Tesla. Fascinating fact: Tesla never slept for more than two hours a day. Tesla got more out of the day with his limited sleep schedule. Like Da Vinci, Telsa also followed the Uberman sleep cycle and claimed to never sleep for more than two hours a day and reportedly once worked for 84 hours in a lab without any rest or sleep.
Mark Twain in Nikola Tesla's apartment, New York 1894 The high-voltage current is being passed through the human body to bring the lamp to incandescence. Tesla's friend, Mark Twain, is holding the loop above the resonating coil. Tesla is in the background. Originally published as part of an article by T.C. Martin called "Tesla's Oscillator and Other Inventions" that appeared in the Century Magazine (April 1895)