>  But what about the filament life time ? One of the biggest problem
> of the halogen lamps appear in the cold-warm transient of the
filament.
> The PWM is keepig the same pulse current through the filament, even
> the effect for the eyes it's a dimmer light.
> I saw many lamps dying like this with a lot of electronics nearby.

You really don't want to dim a halogen unless you need to.  The heat is
required to drive the cycle that re-deposits the tungsten on the
filament.



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