An electric arc is an electrical breakdown of a gas which produces an ongoing plasma discharge, similar to the instant spark, resulting from a current flowing through normally nonconductive media such as air. A slightly archaic term is voltaic arc as used in the phrase "voltaic arc lamp".

The various shapes of electric arc are emergent properties of nonlinear patterns of current and electric field. The arc occurs in the gas-filled space between two conductive electrodes (often made of carbon) and it results in a very high temperature, capable of melting or vaporizing virtually anything.

On a commercial basis, electric arcs are used for welding, plasma cutting, for electrical discharge machining, as an arc lamp in movie theater projectors or street lamps (historic), and to produce aluminum and sometimes steel using scrap. Calcium carbide is made in this way as it requires a large amount of energy to promote an endothermic reaction (at temperatures of 2500 °C).

Low-pressure electric arcs are used for lighting, e.g., fluorescent tubes, mercury and sodium street lamps, camera flash lamps, plasma displays, and neon signs.

Plasma path

---

Capturing the various shapes of the plasma path of an electrical arc has been demonstrated in a G4techTV technology tips video to destroy data on compact discs (CD) by placing the compact disc in a standard microwave oven on high for about 10-15 seconds. Each resulting disc art is unique. No two discs are ever the same. As with any electrical arc application, common sense should be observed in this process. The plastic compact disc media will instantly become hot in this process so waiting a few seconds after the etching process is required to avoid painful burns. The only undesired side effect of this process is a slight displeasing odor similar to that of burning hair. It should be noted that recordable CDs use organic dyes. These organic compounds are liable to change once exposed to high-heat arcing so the displeasing odor may be toxic.

See also

---

• Arc transmitter
• Arc welding
• Spark gap
• Vacuum arc

External links

---

• Unusual Arcing Photos
• Some more info about making electric arcs using a welder.
• Videos of 230,000 volt 3-phase "Jacobs Ladder" and unintentional 500,000 volt power arc

Electricity | Plasma physics

Lichtbogen | Elektra arko | Arc électrique | Arco elettrico | Łuk elektryczny | Электрическая дуга | Ljusbåge | 电弧