Halogen bulbs life

[Grumps]

Hello All

Does using a dimmer reduce the life of a halogen bulb (78mm 240V 100W linear), or increase it?

[Andrew Gabriel]

Increase it, generally.

There's a theoretical possibility of reduction if the bulb wall temperature drops below 250C (which stops the halogen cycle) whilst the filament temperature is still high enough for significant filament evaporation to occur, but I don't believe this is the case with any current halogen lamp designs.

It was possible with the first halogen projector lamps which didn't run the bulb wall as hot as today's halogens do (because the pinch seals would fail at 350C, a lower temperature than is the case today).