Tesla coil
Tesla coil
Named for its inventor, Nikola Tesla, Tesla coils are "fantastic high voltage long sparking displays" that can millions of volts of electricity. These contraptions can produce millions of volts from much smaller voltages.
History
Around 1891, the invention's namesake began experimenting with devices that could create different change and influence electricity. Tesla's main intention for creating this device was to test the theory of electromagnetism proposed by Heinrich Hertz. By putting together various capacitors and alternators (along with other parts in different iterations), Tesla was able to create the recognizable coil with the ball on top that we see today.
Fundamental Principles
Tesla coils can produce massive electric fields due to the ability to create high voltages. It is comparable to a transformer, yet there are key differences between the two.
While a regular transformer relies on the turns of a coil, Tesla's devices are more affected by the "resonance" instead. A major part of this "resonance" effect is through the spark plug gap (in most variations). With a significant amount of voltage, the internal spark plug gap will become ionized air, becoming a sort of circuit.
Through a series of capacitors, the coil can produce the millions of volts that are popularly seen.
The equation to find the voltage is
V2 = V1\sqrt{C1 \ C2} = V1\sqrt{L2 \ L1}
where V is the voltage, C is the capacitance, and L is the inductance.
Usage
Currently, there is no practical use for Tesla coils other than for visual displays. While the shows they create are nothing short of spectacular, the actual uses are fairly minimal.
Future
Due to the large amounts of voltages that they can create, Tesla coils could potentially provide wireless transmission of power. This would allow the transition away from cables and instead to a more mobile form of electrical power. However, the technology is still difficult to implement due to cost and distance limitations. With more advancements in technology, this idea could potentially become reality.
See also
http://www.physicsbook.gatech.edu/Nikola_Tesla
Further reading
External links
References
http://scipp.ucsc.edu/edu/tesla/teslacoil/whatisateslacoil.html