Electrodeless lamp

The internal electrodeless lamp or induction light is a gas discharge lamp in which the power required to generate light is transferred from outside the lamp envelope to the gas inside via an electric or magnetic field, in contrast with a typical gas discharge lamp that uses internal electrodes connected to the power supply by conductors that pass through the lamp envelope. There are two advantages to elimination of the internal electrodes:

Two systems are described below – plasma lamps, which use electrostatic induction to energize a bulb filled with sulfur vapor or metal halides, and fluorescent induction lamps, based upon a conventional fluorescent lamp bulb in which current is induced by an external coil of wire via electrodynamic induction.

In 1705, the scientist Francis Hauksbee demonstrated that in a rotating glass globe with internal vacuum like in a barometer, filled with mercury, and statical charged by holding a hand against the rotating globe, a light phenomenon occurred, so bright that one could read a paper.

Nikola Tesla demonstrated wireless transfer of power to electrodeless lamps in his lectures and articles in the 1890s, and subsequently patented a system of light and power distribution on those principles.

In 1967 and 1968, John Anderson of General Electric applied for patents for electrodeless lamps. In 1971, Fusion UV Systems installed a 300-watt electrodeless microwave plasma UV lamp on a Coors can production line.Philips introduced their QL induction lighting systems, operating at 2.65 MHz, in 1990 in Europe and in 1992 in the US. Matsushita had induction light systems available in 1992. Intersource Technologies also announced one in 1992, called the E-lamp. Operating at 13.6 MHz, it was to be available on the US market in 1993.

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