Durst cls 1000 color head question

[frotog]

I recently acquired a Durst cls 1000 color head. I've noticed that the light output does not step down when the enlarger is left idle between prints. Is this normal or should the head go into a standby mode, stepping down the intensity of the output of the bulb and thereby increasing the lifespan of the bulb?

 

[GeorgesGiralt]

Hi !
An halogen bulb suffer when it is not lit full power. The whole thing works if, and only if, it is left running really hot.
If you want to lengthen the life of any halogen bulb, let it run at full power continuously. My tooth doctor let the lamp above the patient's head always on from 7 am in the morning to 8 pm when he leaves. This way, the "special" bulb (a slide projector bulb, BTW) has a lifespan of 3 years....

 

[frotog]

Thanks for your response George. Your post reminded me of how rheostats can wreak havoc on tungsten globes. Nonetheless, I seem to recall working with a cls 2000 head that would go into standby mode, knocking down the intensity of the light when it was left idle. I'm just trying to make certain that this head is operating as it should.

 

[GeorgesGiralt]

Well it may be to cut heat without consideration for light bulb lifespan.
My CL450 only turns on when the timer said so, but a fan runs when the bulb has been lighted on for more than 5 seconds.... And remains on for a whole minute even if the bulb is not lighted anymore.