Tesla coil building is a threat you really need a lot of passion and a lot of hours studying. Hard work is the only way for succeeding.
Tesla used these circuits to make innovative experiments in electrical lighting, phosphorescence, X-ray generation, high frequency alternating current phenomena, electrotherapy, and transmission of electrical energy without wires.
Furthermore Tesla coil is an electrical resonant transformer circuit created by Nikola Tesla. Tesla used this invention to liberate all electricity power