The tesla coil is one of Nikola Tesla's most famous inventions. It is essentially a high-frequency air-core transformer. It takes the output from a 120 v-ac to several kilovolt transformer and driver circuit and steps it up to an exteremely high voltage. The Colorado Springs Tesla coil was reported to have reached up to 12,000,000 volts in 1899 and in that same year he told friends that he got the coil to reached 100,000,000 volts. So i think it time for are government to tell the truth about Nikola Tesla's and we need to demand it. Thanks KJF.