subject: Halogen Lighting – What are Halogen Lights and Lamps? [print this page] Author: Art Icklewright Author: Art Icklewright
The word halogen refers to a series of non-metal elements from the periodic table of elements. These halogens are combined with inert gas within the halogen lamps. Typically the main halogens used in lamps are iodine and bromine. Halogen lamps are incandescent lamps; in other words, the light is driven by heat. The heat (and subsequent light) are produced when an electric current is passed through a filament inside the lamp. In this sense it has something in common with traditional incandescent light bulbs. There are however a number of important differences. In traditional incandescent bulbs, when a current is passed through the filament in them to produce the heat and light, the filament gradually evaporates and is deposited on the inside of the bulb glass. This is why the glass looks black when the filament finally breaks and the bulb no longer works. In halogen lamps, there is atungsten filament. It too evaporates when heated, BUT the evaporated tungsten reacts with the halogen so that it is deposited back onto the filament instead of staying on the inside of the glass. This rebuilding / regenerating cycle of the filament allows halogen lamps to last much longer than conventional incandescent bulbs. Halogen lamps run at higher temperatures, the filament is closer to the surface of the lamp, and the surface itself is generally smaller in size than other traditional bulbs. All of this means that they need a stronger glass this is usually quartz or high melting point glass. Why Halogen Lamps? So some of the main benefits of these essentially incandescent lamps compared to traditional ones can be summed up as follows: They are much longer lasting because of the chemical reaction between the tungsten filament and the halogen. There is a much higher light output proportional to the voltage used i.e. it has a much higher efficacy. They can be used to create a wider range of effects i.e. they are more flexible for producing targeted lighting effects around the home. Examples of the range of halogen lamps available include linear halogen lamps (150w to 500w) in short and normal (117 mm) sizes, and G10 halogen spotlights. The spotlights are also available in an energy saver range that gives a 20% energy reduction.About the Author: