Electrical insulators, when subjected to a high enough voltage, undergo an electrical breakdown. When Electrical Breakdown occurs the electric current starts flowing through the insulator and what was the insulator then becomes an electricity conducting substance after electrical breakdown.
In other words, Voltaic arc or plasma is the electrical discharge which occurs in the insulating substance during an electrical breakdown, and this happens at a specific voltage and specific conditions in an insulator.
The electrical spark can take place in an electrical insulator ( be it plastic, SF6, mineral oil, and even air or a vacuum). A dramatic electrical arc, with which we are all familiar with, is lightening, where the insulator is the air.
This natural phenomenon of arcing or sparking was first scientifically described by Sir Humphry Davy, in an 1801 paper published in William Nicholson’s Journal of Natural Philosophy, Chemistry, and the Arts.
Today this natural phenomenon is very well understood and has a vast variety of applications. Many technologies using plasma have been developed over the last 200 years to help us in everyday life.
Let us look at some of the applications of electric arcs, they are used in:
→ Welding, for industrial applications
→ Industrial cutting, for manufacturing
→ Electric or Plasma arc furnaces, for melting
→ Electrical discharge machining (EDM), also referred to as spark machining, spark eroding, burning, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained using electrical sparks.
→ Arcing is also used in modern domestic and industrial light bulbs, Spotlights, Theater lighting, metal halite lamps, high-frequency lamps and many other types of light bulbs.
→ Spark plugs are used in the internal combustion engines of vehicles to initiate the combustion of the fuel in a timed fashion.
→ Arcing is used in movie projectors.
→ Electrical Arcing devices have been used extensively for timed detonators (in a controlled demolition).
→ They are used to ignite our gas in domestic hobs.
→ Electrical arcing in being studied for Electrically powered spacecraft propulsion.
→ In Medicine electrical arcing has been in use since early 1900 for electrocoagulation, destruction of tumors and more…
→ In Aesthetics electrical arcing is used for tattoo removal, skin tightening, benign mole removal etc.
All those applications and more, take advantage of the simple and well-known phenomenon of electric arcing.
The few applications we have seen are those in which the properties of electrical arcs have been harnessed to our advantage.
Sometimes, voltaic arcs are not desired physical phenomena. In electric circuit breakers, entire technologies have been developed thanks to the requirement to control and extinguish the arc. Electrical arcs are also unwanted and suppressed in electrical motors, and in oil filled powered transformers, in which a spark (or arc) could have catastrophic consequences and even explosions.
So we have seen, how plasma or voltaic arc have been used for many years and has many different applications in everyday life and it is applied in a vast variety of modern technologies, machines, and various devices.
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