Halogen lamp

A halogen lamp operating in its fitting with the protecting glass removed
A halogen lamp behind a round UV filter. A separate filter is included with some halogen light fixtures to remove UV light.
Xenon halogen lamp (105 W) for replacement purposes with an E27 screw base
A close-up of a halogen lamp

A halogen lamp, also known as a tungsten halogen, quartz-halogen or quartz iodine lamp, is an incandescent lamp consisting of a tungsten filament sealed into a compact transparent envelope that is filled with a mixture of an inert gas and a small amount of a halogen such as iodine or bromine. The combination of the halogen gas and the tungsten filament produces a halogen cycle chemical reaction which redeposits evaporated tungsten to the filament, increasing its life and maintaining the clarity of the envelope. For this to happen, a halogen lamp must be operated at a higher temperature (250° C; 482º F)[1] than a standard gas-filled lamp of similar power and operating life, with the side benefit of producing light of a higher luminous efficacy and color temperature. The small size of halogen lamps permits their use in compact optical systems for projectors and illumination.

Due to their relative inefficiency compared to LED and compact fluorescent lamps, halogen bulbs have been banned in many jurisdictions.

History

A carbon filament lamp using chlorine to prevent darkening of the envelope was patented[2] in 1882, and chlorine-filled "NoVak" lamps were marketed in 1892.[3] The use of iodine was proposed in a 1933 patent,[4] which also described the cyclic redeposition of tungsten back onto the filament. In 1959, General Electric patented[4] a practical lamp using iodine.[5]

In 2009, the EU began its phase-out of inefficient bulbs. The production and importation of directional mains-voltage halogen bulbs was banned on 1 September 2016 and non-directional halogen bulbs followed on 1 September 2018.[6] Australia will ban halogen light bulbs from September 2020.[7]

Other Languages
беларуская: Галагенавая лямпа
Cymraeg: Golau halogen
Bahasa Indonesia: Lampu halogen
italiano: Lampada alogena
Nederlands: Halogeenlamp
српски / srpski: Халогена сијалица
srpskohrvatski / српскохрватски: Halogena sijalica
svenska: Halogenlampa
Türkçe: Halojen lamba
українська: Галогенова лампа
Tiếng Việt: Đèn halogen
粵語: 石英燈
中文: 卤素灯泡