Dimmable Pendant Lights?

[Jivemaster]

Halogen lamps NEED a period of full power running to complete the tungsten return cycle otherwise they die quickly.

[timsabre]

Halogen lamps NEED a period of full power running to complete the tungsten return cycle otherwise they die quickly.

 

I have heard this too but it is not true in my experience.

Our church used to be lit with 300W halogen tubes on dimmers, they were always run dimmed (and soft-faded in) and they lasted for ages, a lot longer than the ones running on full power.

 

Also theatre lamps are nearly all halogen and most of them are never run at full.

[Tomo]

Yep, it's a theatrical myth.

 

The halogen cycle doesn't really make much difference to lamp life in itself, as the tungsten halogenides are deposited back on the cooler parts of the filament - the 'legs' - and not the 'active' bright part.

Run dim means less evaporation, so it lasts longer.

 

The real difference halogen makes is that it doesn't deposit metal on the inside of the envelope and block the light. (Well, not much)

 

So the envelope is smaller, thus the gas fill better (higher pressure etc) while still being cost effective and safe (can make it strong enough to not explode*) - so they last longer!

 

* Well, not often.

[alistermorton]

Aside to Tomo's post: I've got a T/26 at home which didn't explode, but blew a pinhole in the envelope. The filaments shot out through the hole forming loops. Looks quite arty.