Film-Tech Forum ARCHIVE: Lumex strike problem

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Posted by Andrew Schmidtke (Member # 4634) on 06-06-2008, 09:39 PM:

Hi I have a weird problem,

I found that I couldn't strike the lamp unless the lamp house cover is off. (cover switch depressed)-and only if the fan is off as well.

Turns out if I shine a torch or bright light on the neon glow lamp on the PC board, the lamp will strike!

(all precautions taken)

Any thoughts on this much appreciated

Posted by Mark Gulbrandsen (Member # 72) on 06-06-2008, 10:02 PM:

I highly doubt that outside light is affecting the neon lamp and causing it to ignite... these ignitors biggest problem is that the high voltage will arc over to ground... from just about anywhere. Turn off the room lights and ignite it... you may see a virtual lightning show in the back of the lamphouse... especially if you're in a humid area. Its highly important to keep the negative lamp lead as far away from any other metal parts in the back of the lamphouse and insulate it with heavy silicone tubing if possible. Another common arc over point is the metal mounting foot that faces the front corner of the lamphouse. The ignitor case is black... made black from Carbon Black mixed into the plastic! Go figure... new ones are white or beige plastic.

Mark

Posted by Andrew Schmidtke (Member # 4634) on 06-06-2008, 10:20 PM:

Thanks Mark

But Heres the thing

At First we were looking, like you suggested, for any arcing with the lights off, didn't see any and the lamp wouldn't strike, then we happened to shine a torch on the board and away it went. We coudn't believe it, tried this again and again and it struck.

The glow neon activates (or part near it reacted)to the light.

Nobody I know has ever come across this, and all a waiting for the solution, most think I am nuts. But this is the only way the projectionist can fire the lamp.

Posted by Louis Bornwasser (Member # 3063) on 06-07-2008, 05:40 AM:

Replace the neon. Also be certain if you have a Lumex or a Super Lumex. I have never seen anything but a BLACK Lumex igniter.

Lumex parts are getting scarce. Louis

Posted by Sean McKinnon (Member # 612) on 06-07-2008, 09:57 AM:

that is WILD! The light must cause a reaction with the neon gas? I am going to make sure to stick this one way back in the filing cabinet of my brain!

Posted by Mark Gulbrandsen (Member # 72) on 06-07-2008, 10:54 AM:

If you do try the Neon be sure to use the correct one. I don't believe it's an NE-2, but check the envelope right where the leads come through the glass... some neons have the type number stamped right into the glass. There are probably close to 100 different Neon lamps that look like that one!

Louis... Lum-Ex parts are not that scarce. The Stupid Trooper uses the Lum-Ex lamphouse so in essence its actually still in production! At least if Wrong International is still making the Stupid Trooper.... The current ignitor is a DC ignitor and is far far more reliable than the old one. One nice thing about the old ignitor was that it was very gentle on the lamp and very quiet... meaning low RF noise generated. All you hear is a little "bink" and the lamp lights. Ahh, the things that the real Strong Lamphouse Company used to design were actually pretty good stuff.

Mark

Posted by Tim Reed (Member # 137) on 06-09-2008, 03:56 PM:

I never have a problem with them.

Posted by Andrew Schmidtke (Member # 4634) on 06-22-2008, 08:03 AM:

I recieved, what I was told was, a replacement igniter unit for a super trooper, But it doesn't Fit! its reverse, positive goes to where? and you terminate the PC board power, what? - so how does that work?
BTW we are still using a torch to strike the Lamp.

Please help

Posted by Mark Gulbrandsen (Member # 72) on 06-22-2008, 10:01 AM:

Yes, The lamps in Stupid Troopers are reversed and for a good reason. Many operate outside of the lamp manufacturers reccomended angle of operation hence it voids the lamp warranty. In this case gravity may well force the arc up away from the electrodes either extinguishing the arc or possibly burning right through the envelope of the lamp itself. Reversing the bulb more or less elmiminates this problem. There were even some reversed Lumex Lamphouses operating in theaters in Chicago that have extreme down angle for many, many years.

Now weather or not you can simply reverse the polarity going to the control board in your DC ignitor and use it that way I can't answer, however you CAN reverse your power supply connections, meter connection, and lamp and expect almost as much light out of the lamphouse running the same way they did in Chicago.

Mark