Film-Tech Forum ARCHIVE: Bulbs won't light EASILY...

This is topic Bulbs won't light EASILY... in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Frank Dubrois (Member # 3042) on 05-01-2005, 11:24 AM:

We have 3 projectors (new), Strong Highlight IIA lamphouses that just don't like to light the lamps on the first, second, thrid..or sometimes even the 7th try. We thought the bulbs could be garbage, however in our older lamphouses (different manufacturer as well) they strike the first time..everytime. I'm sure the audience doesn't appreciate being treated to a strobe slide show, and the installers keep blaming cheap bulbs, so what do we do? Any ideas? Adjustments?

Posted by Darryl Spicer (Member # 711) on 05-01-2005, 11:35 AM:

what bulbs do you use? Are the connections all tight? Are the units set to the right current levels? On all the units that are having these problems, just manually start the lamp until the lamp stays on and then just hit the start button. Remember to turn the manual switch back off. The audiance will never know you have a problem.

Posted by Mark Gulbrandsen (Member # 72) on 05-01-2005, 11:57 AM:

It could be several things but check your operating current first when you do get one to light and be sure its in the proper operating range. Could also be the HV pulse arcing over to the mirror or other metal item near the lamp, or it could be bad DC ignitors..... Strong has had their share of problems with them. What type of buibs are you having the trouble with? That can make a big dofference.

Mark

Posted by Frank Dubrois (Member # 3042) on 05-01-2005, 01:56 PM:

Well, I didnt think it was the bulbs simply because our older units have no problem lighting them at all. The units that do have a problem are new. They all do the same thing. We use ASL bulbs.

Posted by Alan Dallas (Member # 2537) on 05-01-2005, 02:35 PM:

Never worked with Strong lamp houses but I do know that when I get a "hard to strike" lamp in our Christie Lamp houses I know it's time to clean and regap the Igniter. Especially if the lamp is newish.
I'm thinking maybe a combination of problems. Gap not set right and igniter delay not long enough to build enough voltage to strike. If your lamp house has a Amp/Volt meter like the Christie does switch it to Voltage and watch it as it attempts to strike. Do you get around 4x the lamps rated operating voltage. Normally it's Watts divided by 100. Ex: 3kW lamp operates @ approx 30 volts which nominally needs 120 Volts to strike an Arc.

*shrug* something to look at anyway.

Posted by Frank Dubrois (Member # 3042) on 05-01-2005, 04:12 PM:

Yes it is...thank you!

Posted by Don Sneed (Member # 955) on 05-01-2005, 08:38 PM:

I am in Japan finishing a 12-screen install with the same console, the bulbs here are doing the same thing, it turned out to be these Christie bulb we are using (3K), the two big houses are using using 4500 LIT & we have no problems with these...I check everything on the High rect. power supply...it is the bulbs here not the console or power supply...

Posted by Frank Dubrois (Member # 3042) on 05-01-2005, 10:23 PM:

Well, the bulbs work fine in our other consoles with no flickering or problems lighting, only in our new lamp houses, so I think that rules out the bulb...

Posted by Kevin Orman (Member # 3076) on 05-02-2005, 08:25 AM:

quote: Frank Dubrois
Well, the bulbs work fine in our other consoles with no flickering or problems lighting, only in our new lamp houses, so I think that rules out the bulb...

No, not neccesarily. It appears that some lamps can behave differently with different igniter/power supply combinations. I have heard for example that some of the 'more economical' power supplies have difficulty striking an Ushio lamp but not an Osram.

At one screen I worked at years ago one of the machines used to do very nasty things when the lamp was struck - one time taking-out the motor control card on the Christie AW3 and another time the power supply card on the dolby unit!