In class, Tom Vales introduced us to some amazing devices. Some of these devices were invented in the 18th century. The purpose behind some of them was mainly to generate electricity. It is really interesting for me to see how the development of making generators has become from the past up until the present. It is very crucial for every electrical engineering student to have knowledge about these various electrical inventions. 

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. His invention of the alternating current motor set the stage for the power and lighting systems now used every day around the world.

here is a link that explain how it is works

https://www.youtube.com/results?search_query=tesla+coil+how+it+works