About 100 years ago Nikola Tesla invented his "Tesla Coil". For about 70 years hobbists and engineers alike have been constructing their own Coils. At this point you may be asking yourself why? What is it that these people find so fun about building a large lightning generator? Well perhaps the best answer to both questions is that they want to have fun with electricity. They want to see how large the discharges from their coil can be. It is like any other hobby...with a decidedly dangerous element. But let's begin with a little history of some uses that the Tesla Coil has seen, beginning with Nikola Tesla's intended applications.
Tesla invented his coil with the intention of transmitting electricity through the air. He conducted much research in this area. Indeed he spent the majority of his career attempting to achieve wireless power. His setup was simple. He purposed using a few coils spread across the globe to transmit electrical energy through the earth. Where ever power was needed one would need only a receiving coil to convert the power into a useful form. Tesla had some successes in this area but his investors found it impractical and refused to support further research.
The wireless power research was not a total loss however. Tesla also used the coils to experiment in radio transmission. Indeed today at the very heart of every radio on will find a circuit exactly like that used in the Tesla Coil. The basic principles of transimitting information over radio waves have not changed since Tesla's time. It is interesting to note that although Marconi is widely regarded as the inventor of radio, in 1943 the United States Supreme Court overturned Marconi's patent on radio because Tesla's work had predated Marconi's.
As time progressed, Tesla's claims about the coil became more sensational. He claimed that he could use it to build Death Rays and other wild inventions. Indeed some people believe that Tesla was responsible for creating the Tunguska Creater using his Colorado Springs coil.
Many modern Tesla Coil projects begin as high school science projects. The builders don't have any real agenda in building the coils other than making it more efficient and better than the next guy's coil. These high school project coils often don't see exhibition outside of the builder's garage . Some people, on the other hand, build large coils for demonstration purposes and public exhibitions. As alluded to on the 'home' page many science departments have a Tesla Coil because they make an impressive demonstration of numerous electrical laws.
As you might have guessed, the majority of exhibition coils are not used for merely academic purposes. When you see good electrical effects in movies, like in the Terminator movies for example, the special effects department has employed a Tesla Coil. Moreover, many coils are used at public venues. A few that immediately come to mind are the following: The Burning Man festival, Man or Astroman concerts, and haunted houses.
While the majority of coils are used for entertainment only, some researchers in the area of Ball Lightning frequently use high-powered Tesla Coils to generate the strange phenomenon of Ball Lightning. One application in particular has been in testing airplane fueselages for electrical resillience. Researcher use the coil to simulated a lightning bolt strike on an aircraft in flight.
In addition to seeing uses in industry and people's garages, Tesla Coils
can be found in people's homes and on the shelves in department stores.
The Plasma Ball that many people are familliar with is in fact a Tesla
Coil. Recently another form of Tesla Coil has entered the commercial market.
It is called Luminglas. It looks somewhat similar to a plasma ball but
it is flat and comes in a couple different colors. As with plasma balls
one can touch the Luminglas and see it direct electricity to your finger
tips. Both of these commercial versions of Tesla Coils are completely safe
in contrast to their garage-born counter parts.