8mm Forum: weak lightbulb/lamp

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Posted by Jon Anders Klausen (Member # 818) on June 14, 2009, 03:14 PM:

Hi,
I have a question about lightbulbs. I just bought a Copal CP55 projector. It has a 50W, 8V lamp. When I run the projector it barely gives of light. It looks like it's not getting enough power, but it (the projector) is set to the correct amount (230V in Norway).

Is it possible for a bulb to weaken, but still work?
Can I boost the power to the bulb somehow?

Or should I just buy a new bulb?

Posted by Alexander Lechner (Member # 1548) on June 14, 2009, 03:31 PM:

Hi,
the filament in light bulbs get so hot that tungsten particles come off and condense again on the glass. So on the one hand the reflector in the 8 V, 50 W lamp goes a little bit "blind" and on the other hand the glass gets foggy on the inside and less and less light can leave the lamp.
BTW: halogen lamps (which the 8 V, 50 W lamp is not, as far as I know) contain halogenic gas that is able to reverse the action and bring the tungsten that got stuck on the glass back to the filament.
I hope that has answered your question.

Posted by Jon Anders Klausen (Member # 818) on June 14, 2009, 03:42 PM:

Hi Alexander,
Thanks for your reply!

edit: Problem solved. It was just my small knowledge that was the problem [Embarrassed]

I ran the projector WITH film, and the bulb works like it is supposed to. Bright as the sun [Smile]

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