Ceravision is a privately owned lighting company based in
Milton Keynes
Milton Keynes ( ) is a city and the largest settlement in Buckinghamshire, England, about north-west of London. At the 2021 Census, the population of its urban area was over . The River Great Ouse forms its northern boundary; a tributary ...
, UK. Ceravision is the inventor of High Efficiency Plasma (HEP) lighting technology, a new and unique genre of
electrodeless lamp
The induction lamp, electrodeless lamp, or electrodeless induction lamp is a gas-discharge lamp in which an electric or magnetic field transfers the power required to generate light from outside the lamp envelope to the gas inside. This is in co ...
s, driven by radio frequency (RF) and particularly suited to medium and high power commercial applications.
HEP lighting technology is ideally suited for a number of high-output commercial lighting applications. Ceravision has exploited the ability to use various doses to efficiently deliver tailored spectra for particular applications. The company has launched an HEP plasma grow-light for the horticulture and hydroponics markets that delivers the blue-light, UV-A and UV-B missing from most available grow-light spectrums in the market. However, HEP plasma lighting technology lends itself to several other high-output applications including lighting for: reptile houses; artificial coral growth; insect breeding; TV film and studio; and ultra-violet (UV-C) water sterilisation.
Electrodeless lamp
Electrodeless lamp
The induction lamp, electrodeless lamp, or electrodeless induction lamp is a gas-discharge lamp in which an electric or magnetic field transfers the power required to generate light from outside the lamp envelope to the gas inside. This is in co ...
sulfur lamp
The sulfur lamp (also sulphur lamp) is a highly efficient full-spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. They are a particular type of plasma lamp, and one o ...
, had been very large. The invention took advantage of the high
dielectric constant
The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insulat ...
of
ceramic
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...
to create a very small
waveguide
A waveguide is a structure that guides waves, such as electromagnetic waves or sound, with minimal loss of energy by restricting the transmission of energy to one direction. Without the physical constraint of a waveguide, wave intensities de ...
to constrain and focus the radio waves. Though the resulting lamp was small and produced a large number of lumens per watt at the bulb, the lamp efficiency was low since 80-85% of the light generated is trapped inside the opaque ceramic waveguide.
Ceravision's invention was a clear
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
waveguide
A waveguide is a structure that guides waves, such as electromagnetic waves or sound, with minimal loss of energy by restricting the transmission of energy to one direction. Without the physical constraint of a waveguide, wave intensities de ...
and integrated lamp, which forms a single piece construction. The generated light can now be collected because the waveguide is optically clear, giving excellent lamp lumens per watt. The integrated burner and waveguide, which is source of light, is very small meaning that it is possible to design exceptionally efficient luminaires. HID (
high intensity discharge
High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tub ...
) luminaires have typical utilization efficiencies of 75%.
Fluorescent lamp
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet lig ...
luminaires have efficiencies of 70% - meaning that 25% and 30% respectively of the light produced by the lamp is wasted. The ionCORE range has utilization efficiencies of more than 90%. The burner is integrated into the thick walled quartz waveguide, high powers from 100 - 5000W's are possible without damage to the lamp.
The second issue - long life, low cost RF generation has been solved using a combination of a
magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while ...
with a specialized controller. Magnetrons are manufactured in large volumes for use in microwave ovens and are able to produce RF power at low cost.
The historic problem with magnetrons had been their short life (the life of a microwave magnetron was typically c.2,000 hours). Ceravision has developed a method of extending the life of magnetrons to over 40,000 hours. Ceravision has an agreement with Toshiba to develop high efficiency magnetrons."Ceravision and Toshiba Electronics Sign Development and Supply Agreement to Advance High Efficiency Plasma Technology" ''
PR Newswire
PR Newswire is a distributor of press releases headquartered in Chicago. The service was created in 1954 to allow companies to electronically send press releases to news organizations, using teleprinters at first. The founder, Herbert Muschel, ...
''
The lamp consists of four integrated elements; a quartz RF resonator and integral plasma burner (lamp), a transition unit (the system which couples the RF source to the resonator), a
magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while ...
, and an AC power supply. The resonator and integrated burner contain an inert gas and metal halide salts. Microwave energy ionizes the gas to form the plasma which combines with the metal halide to vaporize the metal halide salts and produce the light.
See also
*
Luxim
Luxim is a privately owned clean tech company based in Sunnyvale, California, which was founded in 2000.
Luxim manufactures a solid-state electrodeless lamp lighting system. Luxim technology is used in general lighting, entertainment lighting, in ...