Projector SO CLOSE to being setup!

[Walt Shires]

Hi Everyone,

I'm know I'm not a known person around here so here's a quickie. I'm one of those that went to film school - worked sort of to the side of the film industry (I worked on Final Cut Pro) and have always been into home theater. Around the year 2000 I saved this projector from a theater that was being torn down to turn into a climbing gym. I had it up and running at that time - but, life basically had me moving it around and not really getting to run anything for the past 20 years (boy... it's hard to think I can say that!) But now we've built a medium home theater with a projection closet in the back in hopes of getting the projector up and running. Watching previews and maybe a movie or two!

What I have is a Century Model C projector with a Christie Xenolite Lamphouse. I have the rectifier that came with it - but it's 3 phase and it's no longer working. I don't actually know if the lamphouse still works but - I hope so. What I need help with is getting another rectifier that would work with the lamp house - or getting a different lamphouse/rectifier setup. I have the Century pedestal that goes with it.

I'm up for creative ideas too. Such as I read about another person (somewhere on the internet) using a Welder from harbor freight as the rectifier. Anyway - any help/pointers/tips would be MUCH appreciated! Here are some photos including the spec plate from the rectifier that doesn't work currently:

Projector.jpg lamphouse.jpg rectifier spec plate.jpg

[Leo Enticknap]

If you don't have a least a single phase 208 or 240 supply, I'm not sure that it's going to be possible to get a xenon arc lamp working inside a residence.

Here is a totally wacky idea to be laughed at. These guys make LED retrofit kits for Victorian era magic lanterns, claiming 9,000 to 10,000 lumens of output. Someone who is far more of an expert on lamphouse optics than I am would need to advise if it would be feasible to install one in this lamphouse nondestructively, and if so, if it would give sufficient light for a home theater screen and without causing heat damage to the film. But the feasibility might be worth investigating.

[Ryan Gallagher]

If you don't have a least a single phase 208 or 240 supply, I'm not sure that it's going to be possible to get a xenon arc lamp working inside a residence.

Here is a totally wacky idea to be laughed at. These guys make LED retrofit kits for Victorian era magic lanterns, claiming 9,000 to 10,000 lumens of output. Someone who is far more of an expert on lamphouse optics than I am would need to advise if it would be feasible to install one in this lamphouse nondestructively, and if so, if it would give sufficient light for a home theater screen and without causing heat damage to the film. But the feasibility might be worth investigating.

I've also considered what a vertical "LED Filament" style LED card headlight bulb would do in a lamphouse. In the US they can be 8k to 13k lumens. Obviously point source would be better. I contemplated this idea for our museum brenkert supreme if and when it ends up as a lobby display. Doesn't need to do much, just throw something resembling an image.

Do those 3phase converters for motors often used on machine equipment provide adequate power for a rectifier? They come in 15A and 60A output flavors:
http://https://www.grainger.com/product/787PK3

But at those prices just getting 208 installed by your electrician might be cheaper.

[Walt Shires]

In the past - I contemplated the high wattage LED Chips you see on eBay but it was big money to buy. This time - the whole package was only 35$ for a 6500K 100W chip LED with the power supply, heatsink, and a focusing lens. So... it's on the way from China. This setup I will try right behind the shutter - basically bypassing the lamphouse entirely.

I looked at the LED headlamp bulbs too - and the numbers are certainly good - I just wonder if the numbers are legitimate. But - for 50$ I figure I can try that also. That would be installed in a way to simulate where the arc would be in the lamphosue. We'll see how both goes.

In the past - the LED thing everyone seemed to poo-pooh, but... I figure at this low dollar amount its' worth a shot.

I'm also lucky enough that when I grabbed the projector I grabbed any papers I saw - so I have the instruction book and circuit diagram for the Rectifier. I'm am going to try a few things with it to see if I can get it to work. Meaning replacing the capacitors and double checking for wiring problems and shorts.

I also found a product catalog of that timeframe and was able to see the lapmhouse supported 2500-3000w bulbs with the power supply I have. The series of lamphouse supported lower - down to 900- watt bulbs. So....MAYBE I can put a lower wattage bulb in there - and then try running the rectifier with only 2 legs of power and see what it does. All sort of a shot in the dark, but, also there are a lot of videos on YouTube that explain rectifiers - smoothing out the power - all this info that I never had access to before.

I can get 220 to the room easily - but, 3 phase is not available in residential areas. Also, as I research it's starting to look to me that the 3 phase maybe wasn't about "power" necessarily, but about smoothing out the DC voltage that came out of the rectifier because of the way it's used in the projector situation. These days you can get those 1 farad capacitors for car stereos for 20$ - I think big capacitors might have been really expensive then so they had other ways of doing that that were less expensive....? I'm just throwing out and idea here... I don't actually know.... yet.

I bought and used the motor 3 phase convertor thing when I first got the projector - but, it made the rectifier buzz BIG TIME. When it was in my garage and we were just playing around it was OK but it won't be in the new situation.

It'd be great to find some sort of setup to use that isn't a hack. But, in the meantime...I'm gonna try some hacks!

Thanks for the input! I'll let y'all know what happens and things as I figure them out.

[Ed Gordon]

...
What I have is a Century Model C projector with a Christie Xenolite Lamphouse. I have the rectifier that came with it - but it's 3 phase and it's no longer working. I don't actually know if the lamphouse still works but - I hope so. What I need help with is getting another rectifier that would work with the lamp house - or getting a different lamphouse/rectifier setup. I have the Century pedestal that goes with it.
...

Walt, I assume you want to use this at home. The simplest solution would be to pick up an old 35mm slide projector and move the optics and power supply to your Century. The trick would be to choose an old slide projector that uses lamps that are still readily available.

[Vern Dias]

I would definitely second going home brew. About 25 years ago I built a pair of lamphouses with condenser lenses from Kodak Carousel slide projectors and CTS 1KW incandescent 16mm projector lamps for my HT (5'x12' 1.0 gain screen.

[Ryan Gallagher]

For those home brewing, I'm curious if and how ya'll addressed the color temperature problem (if you attempted to)... Incandescent and LED are both unlikely to match the intended color temp of xenon/carbon.

But for the purposes of having a single running machine just to show friends and family how it used to work, all that doesn't really matter, as long as you can throw some kind of picture.

Hell they make crazy LED flashlights now that are probably bright enough now too, but beam shape might waste a ton of light. LEP (Laser Excited Phosphor) are interesting too, narrow beam etc. Basically how some laser projectors work. You'd have to do some serious research to find a torch/flashlight that could stay in the mode you need for the required amount of time though. Most downgrade due to heating or to manage battery life.

[Ryan Gallagher]

If you end up still wanting xenon... the cheapest route is probably to find some decommissioned spotlights. The Strong "super trooper" lamphouse was essentially identical to their film lamphouses of the era.

For example: here are TWO that also come with the 208v V2 rectifiers suitable for 1-2.5k lamps, a steal at 600$ OBO.
https://www.ebay.com/itm/13497665064...+super+trooper

Crazily they claim free shipping too, though I somehow doubt that is their intent.

The one caveat with a spotlight lamphouse is usually the douser is not part of the lamphouse, but the operator controls section. Might have to fashion your own light cut-off mechanism or do a bit of jerry-rigging to re-locate the existing chopper or dowser. They will also not typically be wired to allow console/automation control... all manual on/off etc.

[Walt Shires]

I just looked up condenser lens (I didn't know what they were) and I think that the LED chip package I bought has one. I knew it had a lens that basically focused the light into a smaller area (I've had those before) but now I know it's called a condenser lens!

If it all gets worked out via a hombrew method - I'm going to look for a Peerless carbon arc lamphouse just to put on there for decoration - I love how they look!

[Walt Shires]

I just "installed" the headlight bulb. It does work but until I am able to cut the wall (I was sort of waiting to make *sure* I was going to be able to get some sort of light working) I won't know if it's good enough. It is definitely bright - not like a xenon bulb, but if you catch it wrong it does sting your eyes. I made a small holder on the 3D printer (I figure the heat won't be anything like a xenon) so that you could use the adjustments in the lamphouse to reposition the point of light. Anyway - here are some pics

LED-Headlamp-1.jpg LED-Headlamp-2.jpg LED-Headlamp-3.jpg

[Ryan Gallagher]

Fun! The vertical dual reflector design seems more conducive to this approach my single reflector horizontal brenkert (or peerless) which would probably waste 80% of the output!

Looks promising.

when you cut the port hole either go big enough for operator to also see through, or go with two smaller ones.

lots of more flexible modern booths just have a huge window that runs the entire length, for various configurations. Also an option, just gotta control booth lighting better, and sound proofing of the port glass.

[Ryan Gallagher]

I gather that is a single LED package model, only shoots off one side.

When considering horizontal setups I nabbed one of these, with 4 Omni LEDs, but have not tried it yet.

IMG_6040.jpg

[Walt Shires]

The one I got has led on both sides so the front and rear reflector are “working”. It took A LOT of adjusting to get enough light… but, watching a preview at about 4” wide was plenty bright. We’ll see about 180”!

[Josh Jones]

Depending on what wattage xenon you want to run, you can either build a supply for it (I've done that), or we could work out a trade for one of the strong xenon single phase rectifiers I have.

I've done the 100W LED with ebay condenser lens thing in the shutter housing. The light is very yellow and dim. I use it for cutting plates, but its really too dim to watch movies with.

Josh

[Walt Shires]

Hi Josh,

It looks like you've already done exactly what I was going to try - complete with the bare bones power supply. Heck... probably the same ebay seller! I had *some* hopes it might work because the headlamp bulb thing did project a decent image... it's just not bright enough.

Another member here (Ryan) said he used one of the calculators and came up with 575 w needed for my screen (it's a 180" in a fully light controlled theater room. we just built) I remember that the bulb I had when it was working was SUPER bright on the small screen I had in my garage at the time and it's a 2500. My simple brain wonders if 1000 is a better number because it for sure won't be too dim. or if a 575 would actually be fine. I would like it to be properly bright.... but, I'm just a home theater person and planning on watching trailers and probably only do feature lengths for "special events"

I had read a few articles about people who took a 3 phase rectifier and only ran 2 phases to it and it basically just put out less power. I do have the schematic for the rectifier I have... and although I didn't get it running the last time I tried I was going to replace all the capacitors and try again. There is one big one and a handful of disc caps so that will be easy. On that line of thought though.... I don't know how xenon bulbs work. If they are less wattage... do they still run a 30V DC and it's just lower amperage? Or are the both lower amperage AND lower voltage?

Anyway - I would LOVE some help/advice/ideas and appreciate it all! Tell me what you think might be a good approach... or if just using a different rectifier would be the better thing to do. I'm up for any of it.