Film-Tech Forum ARCHIVE: My first Xenon bulb experience

This is topic My first Xenon bulb experience in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004942

Posted by Sam Hunter (Member # 1119) on 05-29-2003, 10:30 PM:

My new screening room project took a big step today as I received a new xenon bulb for my ORC. Most of you old timers and techs out there probably go about this stuff as common acts but this was my first time fooling with this thing. Anyway, installed the bulb, made sure the anode lead wouldn't arc and all that, and hit the go button. A few seconds later I had light. Wow! The bulb is a 1000W and the current level on the ammeter showed 55 amps. When I shut it down I noticed a red glow which was the anode glowing. I freaked out! After I calmed down a bit and thought about it I realized this has to be normal as an arc does generate heat. I called a tech and asked him about it and he said it was fine, as I just needed to reassure myself that I wasn't about to fry a new bulb.
I will be installing a venting system in the morning that will draw air through the lamphouse as long as my booth breakers are on. Is there anything else I should watch out for? I wouldn't think so. Also to my dismay I had to jack up the lamphouse about 1.5" so that it would line up with the projector. I guess if I would have replaced that Simplex mount with an RCA and not used the adapter then it would have lined up. In any case I have a nice light source now.
Paul, that power supply works great! 3 replacement regulators, 3 fuses and a blast of high-pressure air fixed it right up. Thanks!
My homemade automation works great, the xetron failsafe works fine and all I am waiting for to begin screenings is my new screen and automation card (Thanks Mark).
Be posting pics soon.

I do have a question about single projector setups like in platter houses, do they use dowsers and zippers? When I test fired mine it did like Joe's that he was having trouble with, you could see the glow of the anode after you shut it down. However my plan is to use black leader for the tails of my reels so I guess it wouldn't matter too much. I have a Simplex dowser unit that I believe I can retrofit to my BX-80, just have to build a pulser to operate it as I don't think you leave the voltage applied to those things?

Anyway that’s all for now.

Posted by Mark Gulbrandsen (Member # 72) on 05-30-2003, 01:35 AM:

Neato Sam,
You should notice much improved colors too!! The card is on its way via UPS...
Mark

Posted by John Eickhof (Member # 323) on 05-30-2003, 03:01 AM:

Hi Sam, Glad to see you are 'on the screen'! Yes the proper hangar bracket would have made the job a little easier,
but It appears you have it under control! I can't wait to see pix of your final set-up!! Kudos! John Eickhof

Posted by John Anastasio (Member # 607) on 05-30-2003, 05:10 AM:

Yeah, those anodes aren't like the plates on rectifier tubes, Sam! They're supposed to glow. I just set up my brother's Xenon lamphouse and he had the same reaction you did. The look of panic on his face when I shut the thing down and he saw all that bright orange tungsten was priceless. I reassured him that 1.) tungsten can't melt at that temperature and 2.) if you run 55 amperes through a wire that size, it WILL glow! Congratulations on joining the wonderful world of light.

Posted by John Pytlak (Member # 331) on 05-30-2003, 07:14 AM:

That red "afterglow" makes it obvious why the lamphouse ventilation should be left on until the lamp has a chance to cool down. [Eek!]

Posted by Sam Hunter (Member # 1119) on 05-30-2003, 08:12 AM:

Just finished my ventalation system, what a bitch crawling around in attics [thumbsdown]

Here is the almost finished product. Waiting on a go for the porthole from the boss [Big Grin]

[ 05-30-2003, 09:18 AM: Message edited by: Sam Hunter ]

Posted by John Pytlak (Member # 331) on 05-30-2003, 01:02 PM:

quote:
Here is the almost finished product. Waiting on a go for the porthole from the boss

Who needs a port??? Get an x-ray lamphouse and a screen made of phosphors that glow when irradiated. Only works with silver-image B&W prints though. As an added bonus, you can just stand in front of the screen for an instant whole-body x-ray fluoroscope exam. [Wink]

Posted by Sam Hunter (Member # 1119) on 05-30-2003, 01:25 PM:

You know, that would be freakin cool [thumbsup]

If I do it just right I can see what the neighbors wife is wearing [evil]

Posted by German Marin (Member # 918) on 05-30-2003, 01:54 PM:

Hi Sam, Did you check for the bulb/mirror alignment? When I chang the bulb I must to check the luminosity on the screen and move the bulb base (negative) or the mirror (some lamphouses has the mirror movible [Kneisley] or the bulb [Christie]). If you don't do this, the film could be fried or lost color (excesive heat on a little area of frame).

Posted by Sam Hunter (Member # 1119) on 05-30-2003, 02:49 PM:

Hey German,
No I haven't yet but as soon as I install the screen and porthole that needs to be done. Ran it shooting on the wall and you could tell it needed alignment.

Posted by German Marin (Member # 918) on 05-30-2003, 05:43 PM:

Sam, I didn't know the screen hasn't been installed yet. I wish it will be a great place to see movies!!!
Good luck Sam.

Posted by Mark Gulbrandsen (Member # 72) on 05-31-2003, 08:56 AM:

Sam,
Take your time as that lamphouse is a bit touchy to get aligned properly. Being your forst time you may get a bit frustrated with it.....they can do a pretty darn good job though.....
Mark

Posted by Sam Hunter (Member # 1119) on 05-31-2003, 04:21 PM:

Well, I went ahead and tried an alignment and I think I was successful. The only problem I have is that my negative lens appears to be cracked [Frown]

It doesn't seem to affect the picture however and I am sure it wasn't cracked when I got it and I was quite careful handling it as far as finger prints and all. I am not sure why it cracked, maybe there wasn't enough room for it to expand when it got hot [Confused]

Anyway, anybody got one for a ORC X-1600 LH?
Later.

Posted by German Marin (Member # 918) on 05-31-2003, 04:33 PM:

When you align the bulb you should not keep the lens exposed to the light too time because it could be broken (high temperature).
The cause os broken negative lens (pre-objective or pre-lens) is the excessive heat (It's the first in receive the heat).

Posted by Bob Peticolas (Member # 328) on 05-31-2003, 04:47 PM:

Sam,

When I installed our new Knisley II lamphouse, I wired a timer into the lamp circuit. We have one switch that turns on the blower circuit (lamphouse, Strong linear powersupply fans, and the roof exhaust fan). When the air flow sensor in the lamphouse trips, the AC to the power supply is turned on. When the DC to the lamp reaches it's boost voltage, the igniter strikes the lamp. 1-2-3 and we have light. Then I added a timer to the light switch: when it's turned off, the AC to the Strong is cut but the blower circuit is left on for twenty minutes. Plenty of time for everything to cool down.

If there is any blockage or failure of the airflow in the lamphouse, the light either won't go on or it will be cut off-failsafe.

Good luck with your porthole in the wall. [Smile]

Posted by Sam Hunter (Member # 1119) on 05-31-2003, 05:52 PM:

German,
The manual states not to let the light stay on the projection lens but doesn't mention the negative lens. Although you do have a point and I can see where a hot spot could get it.
What do yaw think about leaving the negative lens as is? It seems to show ok so I don't know. I would like to change it though.
Also, Bob I have a ventilator fan in the attic that runs as long as booth power is on and it was working at the time.
Thanks!!

Posted by Gordon McLeod (Member # 33) on 06-01-2003, 08:30 AM:

I have yet to see a M1000 with out a cracked neg lens
They usually crack because during alignment a hot spot gets focused on them

Posted by Mark Gulbrandsen (Member # 72) on 06-01-2003, 08:49 AM:

I have one thats not cracked, but Gord is right as any hot spot will cause uneven expansion of the lens, and its easy to get a hot spot developed with that lamphouse as well as the model 1000. It generally will not cause any problems except that the crack might continue to grow as the lens heats up and cools down over many more thermal cycles. Strong Lum-Ex lamphouses have the same problem. If the lens falls apart just glue it back together with hi-temp red silicone.

As far as the porthole goes....Just go ahead and cut it out....Then hang a photo of a Norelco DP-70 [thumbsup]

sitting just inside its porthole on the side looking into your booth. On your booth side hang a photo of the stage of Radio City Music Hall....... there, you're all set!!
Mark

Posted by Thomas Procyk (Member # 1170) on 06-01-2003, 09:29 AM:

At my very first projection job, it was stressed over and over to leave all the blowers and exhaust fans ON at the end of the night when we shut everything else down. It used to be the policy at first to leave them on for 20 minutes after the show ended, (which was REALLY annoying when trying to go home after midnight shows) but thanks to the wonderful Florida heat and humidity, we came in to find condensation all over the reflectors and inside the lamphouse! [Eek!]

After that, there was an "always-on" policy and we had no problems.

No other booth I have worked in has ever done anything to let the bulbs cool at the end of the night. Just shut everything off and out the door. These "other" booths had various lamp problems from early flicker to just premature darkening.

=TMP=

Posted by Gordon McLeod (Member # 33) on 06-01-2003, 09:06 PM:

I always install a timer on the exhaust so it will stay on 30 minutes after the switch is turned off

Posted by Sam Hunter (Member # 1119) on 06-01-2003, 10:51 PM:

Want to hear something funny?
Yesterday during my adventure I noticed that while I was trying to target the bulb and get my "Bullseye" I noticed that the adjustments I made where drifting. So I turned off the lamphouse, let it cool and pulled the top off. I found that there were two tension springs that needed snugging up a bit and that cured that but anyway, during this I looked at the bulb and noticed that it looked cracked. I said "OH SHIT". ANyway, I reasoned that if the bulb was cracked I would know it by the sound of a small bomb going off. I took another look and found out that it was the little silver wire that is used to ignite the bulb. [Big Grin]

Anyway, this has been one learning experience so far and I really appreciate all the help and insight you guys give me. [thumbsup]

Until next time...Cheers!

Posted by Travis Hubrig (Member # 1745) on 06-02-2003, 04:51 PM:

Sam, I recently found that a bulb can start to crack even while it is operating, I noticed fine 'spiderwebbing' cracks on the anode end of the bulb. It was the first time I have seen a bulb start to crack and still ignite. I am going to try to take pictures of it, but it is not as visible as when it was in the lamphouse.
Good Luck with your project.
Travis Hubrig

Posted by John Pytlak (Member # 331) on 06-02-2003, 07:12 PM:

quote:
I noticed fine 'spiderwebbing' cracks on the anode end of the bulb

Not really a "crack", but vitrification or crystallization of the quartz. Not a good sign. [Eek!]

Posted by Travis Hubrig (Member # 1745) on 06-02-2003, 09:51 PM:

Thanks John,

Not very common? First time I've seen it in 6 yrs working in the booth. It is a bit intimidating trying to change the bulb if it still is pressurized and the quartz has a known defect...

Posted by Sam Hunter (Member # 1119) on 06-02-2003, 10:44 PM:

Now guys, don't get me second guessing myself. These bulbs do have wire laced on the outside right? This bulb is brand new and shouldn't be nothing wrong with it.

Posted by Travis Hubrig (Member # 1745) on 06-02-2003, 11:28 PM:

Sorry, My Fault for throwing you off course...

YES they come with a wire on the outside
It is an 'ignition aid wire'

Posted by Michael Harlow (Member # 1353) on 06-03-2003, 05:21 AM:

Sam, there is normally a nickle wire slung from end to end on the outside, this is to help ignition of a "tired" lamp... Nothing to worry about. [Smile]

Posted by Jeff Taylor (Member # 443) on 06-03-2003, 08:30 AM:

Sam: The toughest thing with xenons, especially after you begin to get comfortable handling them, is to get uncomfortable again. It's a fine balance...a little intimidation is a healthy thing, but it's not rocket science.

Posted by Sam Hunter (Member # 1119) on 06-03-2003, 09:55 AM:

Whew! [Smile]

Posted by John Anastasio (Member # 607) on 06-03-2003, 08:20 PM:

I once had a fellow stop by while I was teaching a production class and pull out a 5k xenon bulb to show me. The damn thing was just sitting on the back seat of his truck. He started waving it around just holding it by one end while I had 15 students standing there and they all couldn't figure out why I quickly shuffled them back inside the studio and locked the guy out. Talk about no respect (do that like Rodney Dangerfield). I haven't had one blow yet, but you're right about getting comfortable with them. It's like electricity....you get cocky with it after a while and that's when you do something dumb like discovering the charge on an igniter with your finger. I'm just glad I had one hand in my pocket the day I took that "across the room" flight. Treat potentially dangerous things with respect and their danger is greatly diminished.

Posted by Leo Enticknap (Member # 534) on 06-04-2003, 02:06 AM:

People fall into one of two categories, IMHO - those who have experienced a xenon bulb exploding and those who have not. It's happened to me twice. The first time was the result of us overrunning the lamp because of a faulty ammeter. It eventually died with a severely blackened envelope and anode lead. I removed the lamp and as I was inserting it into the reinforced plastic tube it suddenly blew up (and yes, I had left the lamp plenty of time to cool before removing it - over two hours in fact). If I hadn't been wearing the full protective visor, gloves and jacket I don't think I'd be sitting here writing this now.

The second occasion was after the cinema had been closed for almost a month because its basement had flooded. We were going through the process of powering everything back up for the reopening. About 2-3 minutes after striking a lamp it suddenly and without warning exploded. I wasn't in the box at the time but am told that there was a pretty impressive bang.

Before these incidents a small part of me thought that there was an element of paranoia in the various urban legends about xenon explosions... not any more.

I've often thought that someone (perhaps one of the major lamp manufacturers) should commission a short film which shows a bulb being deliberately blown up in an enclosed space in order to demonstrate the damage it can do. This could then shown as part of the training for anyone whose job involves handling xenon lamps, in the same way that films of nitrate fires were made for training projectionists in the '30s and '40s.

Posted by John Pytlak (Member # 331) on 06-11-2003, 01:49 PM:

I recall that NASA did make a training film that actually showed large xenon lamp explosions in slow motion. (They use them for solar simulators and lighting up launch pads):

http://osat-ext.grc.nasa.gov/gso/manual/chapter_26.pdf

http://osat-ext.grc.nasa.gov/gso/manual/chapter_index.shtml

Posted by Andrew Duggan (Member # 1302) on 06-11-2003, 03:59 PM:

We were having an issue last night with one of our Xenons not striking at all (ended up being a faulty failsafe inside the lamphouse) and as I was upstairs with the lamphouse open, poking around inside, and at the same time trying to explain to one of the floorworkers (who was up in the booth for some reason) the kind of attention and care you have to give to a xenon bulb. I basically summed it up as: "Working with Xenon bulbs is a lot like mountain climbing. It can be really fun and rewarding, but if you don't give them the proper respect and care, you'll find out just how unforgiving they are. And it'll probably be the last thing you'll ever learn."

Things like this always remind me of the time I was opening the booth one morning at my old job, and on my way to turn on the lights, my foot kicked something in the dark pretty hard. I'm sure you can guess where this is going. So I turn on the light, and lo and behold is a 2000W bulb, just laying there on the floor, looking for an excuse to blow up. I marched down to the office and started raising hell about it and got greeted with that same skeptical "stop being paranoid" attitude. And the kid who left it laying there the night before got no reprimand, no warning, not even a polite request to stop being an idiot...

The gentleman who techs my booth and I have had more than one conversation about possibly one day going out into a feild with a Xenon bulb, painted a bright flourescent color, a long distance air rifle, and a video camera, to try and make a safety video showing the kind of power and range these bulbs have when they go off. Maybe one day...

Posted by John Pytlak (Member # 331) on 06-12-2003, 07:09 AM:

I recall the NASA film used a metal rod on a pendulum, that was remotely released to strike the xenon lamp and make it explode in view of the high speed camera.

Posted by Leo Enticknap (Member # 534) on 06-13-2003, 03:00 AM:

That would be an extremely useful film to have available to the cinema industry for health and safety training, IMHO.

Posted by Frank Angel (Member # 248) on 06-17-2003, 11:16 PM:

OSRAM offers a free VHS tape "Getting the most from your Xenon Lamps" that stresses safety pretty heavily and there are plenty of pictures of the proper way to use the protective gear and how to handle the bulb, but I am pretty sure it doesn't show a bulb explosion, which is a shame. Nor does it show what I think it should show -- what you look like when you've got shards of quartz sticking out of your forehead and eyeballs or how difficult it is trying to thread a projector with those missing fingers, courtesy of a xenon explosion. You need to force-feed this kind of stuff to overcome that inate "I'm invinsible" machismoism that is all to common amoung young guys before they've seen much of the world. You know....make 'em look at what the guy looks like AFTER the motorcycle crash sans the helmet.

The tape says it is compliments of OSRAM and NATO, but it came directly from OSRAM/SYLVANIA -- 978-77-1900 and www.sylvania.com. We made all the spot operators who might have to handle the xenon lamphouses watch it.

Frank