How do Tesla Coils work? First you must understand some basic things about electricity. Electricity is the flow of electrons through a media. The difference in electric potential between two substances dictates the voltage, which can be imagined as the pressure. (Taylor, 2013) Tesla Coils rely on the difference in voltage between two conductors. They have a large primary wire that is wound in a few loops; and a small secondary wire that is wound in thousands of  coils about a glass insulator. When a voltage enters the primary wire, it is transformed into an electromagnetic field. This electromagnetic field passes through the air and through the secondary coils. This process increases the voltage of the wire by the ratio of coils of primary wire to secondary wire. So if the starting voltage is 10V, and there are 300 times as many small wraps as large, the ending voltage will be 3000V. (Hartsfield, 2014) Pictured above, diagram of a transformer. Tesla Coils are fundamentally transformers, with the magnetic field traveling through the air. (Photo credit oneTesla.com) Before the circuit can complete, the electricity enters a capacitor. A capacitor is a device that stores electricity like a battery, but releases its charge all at once. The capacitor is sealed except for a small hole, known as a spark gap. Eventually the charge in the capacitor builds to the point that it can spark out the hole, going to any nearby conductor to generate a closed circuit. This makes visible arcs through the air, each flashing for a fraction of a second, but following similar paths giving the impression of a constant arc. (Hartsfield, 2014)

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