Wireless Electricity? How the Tesla Coil Works
Among his numerous innovations, Nikola Tesla dreamed of creating a way to supply power to the world without stringing wires across the globe. The inventor came close to accomplishing this when his “mad scientist” experiments with electricity led to his creation of the Tesla coil.
The first system that could wirelessly transmit electricity, the Tesla coil was a truly revolutionary invention. Early radio antennas and telegraphy used the invention, but variations of the coil can also do things that are just plain cool — like shoot lightning bolts, send electric currents through the body and create electron winds.
Tesla developed the coil in 1891, before conventional iron-core transformers were used to power things like lighting systems and telephone circuits. These conventional transformers can’t withstand the high frequency and high voltage that the looser coils in Tesla’s invention can tolerate. The concept behind the coil is actually fairly simple and makes use of electromagnetic force and resonance. Employing copper wire and glass bottles, an amateur electrician can build a Tesla coil that can produce a quarter of a million volts.
How the Tesla Coil Works
A Tesla coil consists of two parts: a primary coil and secondary coil, each with its own capacitor. (Capacitors store electrical energy just like batteries.) The two coils and capacitors are connected by a spark gap — a gap of air between two electrodes that generates the spark of electricity. An outside source hooked up to a transformer powers the whole system. Essentially, the Tesla coil is two open electric circuits connected to a spark gap. A Tesla coil needs a high-voltage power source. A regular power source fed through a transformer can produce a current with the necessary power (at least thousands of volts).In this case, a transformer can convert the low voltage of main power into the high voltage.