A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high-frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.
Tesla coil at Questacon, the National Science and Technology center in Canberra, Australia
Homemade Tesla coil in operation, showing brush discharges from the toroid. The high electric field causes the air around the high-voltage terminal to ionize and conduct electricity, allowing electricity to leak into the air in colorful corona discharges, brush discharges and streamer arcs. Tesla coils are used for entertainment at science museums and public events, and for special effects in movies and television.
Unipolar coil design widely used in modern coils. The primary is the flat red spiral winding at bottom, the secondary is the vertical cylindrical coil wound with fine red wire. The high-voltage terminal is the aluminum torus at the top of the secondary coil.
Bipolar coil, used in the early 20th century. There are two high-voltage output terminals, each connected to one end of the secondary, with a spark gap between them. The primary is 12 turns of heavy wire, which is located at the midpoint of the secondary to discourage arcs between the coils.
Nikola Tesla was a Serbian-American inventor, electrical engineer, mechanical engineer, and futurist. He is known for his contributions to the design of the modern alternating current (AC) electricity supply system.
Tesla, c. 1890
Tesla's rebuilt house (parish hall) in Smiljan, Croatia, in the region of Lika, where he was born, and the rebuilt church, where his father served. During the Yugoslav Wars, several of the buildings were severely damaged by fire. They were restored and reopened in 2006.
Tesla's father, Milutin, was an Orthodox priest in the village of Smiljan.
Tesla aged 23, c. 1879
