Film-Tech Forum ARCHIVE: larger projector bulbs

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Posted by Garry Knapp (Member # 9697) on 05-15-2017, 03:25 AM:

Hi again...
I recently bought a lamphouse with a halogen conversion done on it. It came with an OSRAM HLX64663 (36v 400w)
Does anyone know if a higher bulb is available? 600w maybe?
I looked on the OSRAM website,and after my brain began to melt, I gave up...

Posted by Leo Enticknap (Member # 534) on 05-15-2017, 12:50 PM:

The last I knew, halogen or xenon-filled filament bulbs were made in sizes at least up to 1kW for stage lighting. The larger ones may have been superseded by LEDs now, though, and whether larger ratings with the same form factor as yours, and 36v, are available, I couldn't say.

My gut feeling is that you probably could put a bigger filament bulb or an LED array in there, but that it might involve replacing the fitting and/or an upgraded power supply.

Posted by Jonathan Wood (Member # 4614) on 05-28-2017, 05:20 AM:

Hi Gary,
I looked into this myself and I think with 36vdv - 400 w is pretty much your max . Above that you might need to look at AC lamps - a bewildering variety of which are available. In the U.K. We can run about 2kw (blonde) AC lamps from a single phase (220/50) supply . I have experimented with 650 and 800w ac lamps but results were disappointing. The key is the optical arrangement , if your 36/400 uses a condenser / reflector arrangement if will prob give better output than a higher rated ac lamp without such an arrangement. There is a possibility of flicker with AC lamps too, but I never noticed any . I ended up going back to xenon !

Posted by Jim Cassedy (Member # 4115) on 05-28-2017, 12:26 PM:

quote: Jonathan Wood
There is a possibility of flicker with AC lamps too, but I never noticed any

I have a portable Simplex/Atlas projector that came out of a
screening room which uses a 1200w quartz lamp. Never noticed
any flicker on it. I think the hi-wattage filaments have too
much 'thermal inertia' running @ 60hz to exhibit any flicker.

I don't have the bulb # it uses memorized. They're still available
because I think they're used in some stage lighting fixtures, but
they are fairly expensive. A couple of years ago I was able to buy
a crapload of them at a discount on e-bay from some guy who was
getting rid of them. So I won't run out any time soon!

Posted by Garry Knapp (Member # 9697) on 05-29-2017, 05:20 AM:

Hi Jonathan,
I think I have room to expand the output on this. Its an ORCON housing, most of the internals seem to be intact with a reflector and adjustable bulb setup. The transformer thats been installed has room to put a larger bulb as the current 400w only draws about 30% of its capacity. My thinking is that the only constraint would be the pin spacing on the bulb itself.

Posted by Jonathan Wood (Member # 4614) on 05-29-2017, 05:52 AM:

Hi Gary,
If it's the EVD type bulb your using then it's around the same size as a commonly available 650w AC bulb. (I can't remember the code but it's the bulb used in Arri type 650 watt fresnel lights that you see used in tv and film) My point being that your existing reflector arrangement might be a good for this higher power bulb. You would need to buy a suitable socket for it but all you would need is a regular 120vac supply for it . I'm just not sure if DC lamps come much higher than 400w ? I could be wrong though . As Jim said , flicker won't be an issue due to the filament never getting dim enough during the AC cycle . That EVD lamp tends to be a popular choice though in this sort of arrangement, I'm not sure the AC lamp would give noticeably higher output. ELC 24vdc /250 w lamps work well due to their built in reflectors . Jon