Luminos Lighting Limited
Unit F1, Grafton Way
© Luminos Lighting Limited 2015
01256 844 685
Proudly designed and manufactured in the UK
Aside from the method of coupling energy into the mercury vapour, these lamps are very similar to conventional fluorescent lamps. Mercury vapour in the discharge vessel is electrically excited to produce short-
There are two main types of magnetic induction lamp: external inductor lamps and internal inductor lamps. The original, and still widely used form of induction lamps are the internal inductor types. A more recent development is the external inductor types which have a wider range of applications and which are available in round, rectangular and "olive" shaped form factors.
External inductor lamps are basically fluorescent lamps with electromagnets wrapped around a part of the tube. In the external inductor lamps, high frequency energy, from the electronic ballast, is sent through wires, which are wrapped in a coil around a ferrite inductor on the outside of the glass tube, creating a powerful electromagnet called an inductor. The induction coil (inductor) produces a very strong magnetic field which travels through the glass and excites the mercury atoms in the interior. The mercury atoms are provided by the amalgam (a solid form of mercury). The excited mercury atoms emit UV light and, just as in a fluorescent tube, the UV light is down-
In the internal inductor form (see diagram), a glass tube (B) protrudes bulb-
The antenna coils receive electric power from the electronic ballast (C) that generates a high frequency. The exact frequency varies with lamp design, but popular examples include 13.6 MHz, 2.65 MHz and 250 kHz. A special resonant circuit in the ballast produces an initial high voltage on the coil to start a gas discharge; thereafter the voltage is reduced to normal running level.
The system can be seen as a type of transformer, with the power coupler (inductor) forming the primary coil and the gas discharge arc in the bulb forming the one-
In other conventional gas discharge lamps, the electrodes are the part with the shortest life, limiting the lamp life span severely. Since an induction lamp has no electrodes, it can have a very long service life. For induction lamp systems with a separate ballast, the service life can be as long as 100,000 hours, which is 11.4 years continuous operation. For induction lamps with integrated ballast, the life span is in the 15,000 to 50,000 hours range. Extremely high-
Long life span due to the lack of electrodes – Strictly speaking almost indefinite on the lamp itself but between 25,000 and 100,000 hours depending on lamp model and quality of electronics used;
Very high energy conversion efficiency of between 62 and 90 Lumens/Watt [higher power lamps are more energy efficient];
High power factor due to the low loss of the high frequency electronic ballasts which are typically between 95% and 98% efficient;
Minimal Lumen depreciation (declining light output with age) compared to other lamp types as filament evaporation and depletion is absent;
Environmentally friendly as induction lamps use less energy, and use less mercury per hour of operation than conventional lighting due to their long life span. The mercury is in a solid form and can be easily recovered if the lamp is broken, or for recycling at end-
These benefits offer considerable cost savings of between 35% and 55% in energy and maintenance costs for induction lamps compared to other types of commercial and industrial lamps which they replace.
(Diagram showing labelled components of a rectangular style, external inductor type, Magnetic Induction Lamp (ballast not shown)).
(A Philips QL induction lighting system, where (A) Discharge vessel, (B) Tube with power coupler and (C) Electronic ballast)