tungstenhalogen

Tungsten-halogen lamps, a subclass of incandescent lamps, consist of a tungsten filament inside a quartz envelope filled with a halogen gas (commonly iodine or bromine). The halogen cycle temporarily binds evaporated tungsten and redeposits it back on the filament, allowing higher operating temperatures and longer service life than standard tungsten lamps. The quartz envelope is necessary to withstand these temperatures.

During operation, tungsten evaporates from the filament and reacts with halogen to form tungsten halide, which migrates to cooler parts of the envelope. There, it decomposes, returning tungsten to the filament and regenerating the halogen. This cycle minimizes envelope blackening and extends lamp life. Lamps are offered in various base types, including MR16, G4, G9, and screw bases for domestic fixtures.

Applications include stage lighting, architectural lighting, and some automotive headlights. Tungsten-halogen lamps provide bright, crisp light with good color rendering and immediate full brightness, and they are dimmable. They are less energy-efficient than LEDs or compact fluorescents and run hotter, requiring appropriate luminaire design and ventilation. Handling hot lamps with bare skin should be avoided to prevent hot spots on the envelope. In recent years, they have been increasingly complemented or replaced by more energy-efficient technologies, though they remain valued where high color rendering and compact form are important.