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Actually have two questions. How many people leave their bulbs on between shows? Next, I am having trouble lighting the lamp after running multiple shows. Lights fine cold. I've tried to find some info on this and narrowed it down to the ignitor but in all of what I've seen it doesn't mention whether the ignitor actually tries to light the bulb or not when hot. Mine doesn't try to light even. Manually lighting. Xenon lamphouse - Irem ignitor.

Whether you leave your lamp on or not usually depends on how long your down time is. Mine is only 10 to 15 minutes, so my automation controls motorized dowsers and my lamps are always on. Matter of fact, my lamp controls are manual... my automation isn't connected to them.

From watching a thread on this subject (over at "another discussion board"), many seem to feel that more than 20 minutes or so
is a good starting point. You're balancing the cost of electricity against roughly an hour's worth of light (also a subjective number) that you might lose by the additional strike.

SOME bulbs seem to be less prone to wandering, when treated this way. That seems to be how it worked at my place. I really didn't like turning off my lamps during the intermission between shows, but my older lamphouses had no way to close themselves when the projector was off, and 7,000 watts is a bit tough on shutters and douser blades!! Having the electric fire doors fixed all that, so we now turn our lamps on at the beginning of the night and leave them on until closing.
That problem could be in a couple of places, and 3 tech-types will probably suggest 3 different ideas.

Given the fact that temperature can change things in a power supply, I'd check to see what your no-load voltage is when the supply is hot. Since the igniter isn't even trying, it could be that your voltage is close to the line, even when cold. After that, you'd need to find out what triggers the igniter. Some have an adjustment for this, others use zener diodes, so the fix is a bit more complicated.

If you don't already know: The "no-load" voltage across the output terminals should be much higher than what you'll measure when the bulb is lit. You should see upwards of 90-120 volts or so. Make sure you've disabled the igniter before clipping across the power supply.

Is this a problem you've had for a long time, or someting that's just recently started to happen?

You didn't mention what brand the Lamphouse was?

Sorry, brain and fingers weren't in sync when I tried to type Xetron lamphouse. The "other" site is where I was trying to figure out if the ignitor should be trying or not. Since it doesn't try I didn't think it was the gap in my ignitor. My voltage is pegged out 150+ volts prior to lighting and is running where it should when lit. I noticed this problem about a year ago just once when I got a late start on a show and had to relight in five minutes. My guess is that the problem has slowly been growing without my knowledge. The odd thing is this lamphouse in particular is different than my others. There are no safety switches on the door or squirrel cage fan. I noticed that the fan was running across the bulb but not blowing real good when you take the cover off the side of the bulb enclosure so I switched that out and it cooled things overall but did not have any effect on my problem. I've stumped Brightstar at this point. Between show lighting at 20 minutes too short, 25 minutes ok. I can run that fan between shows or leave it off, makes no difference apparently. Would there be a thermal related timer of some sort to prevent ignitor from trying? If so where and what would it look like? Is that what a diode would do?

Not sure on that lamphouse, Knisley uses a zener diode in the igniter circut, do you have a "manual ignitor button"??? if so does anything happen when you hit that?

I forget the voltage of the zener diode but the way it works is when the voltage goes ABOVE the rating of the zener, due to the arc NOT being lit, it passes power to the igniter. once lit, and it falls below (lets say 80 volts) it means the arc is lit thus the ignitor has done it's job and can turn off.

I have had to replace the diode on a knisley before, but the MANUAL button still worked as it had nothing to do with the zener, that is only for the automatic operation of the igniter.

do you have a schematic of the igniter circut???

What model is the lamphouse?

The XH1000/3000 schematic shows a "sensitivity" control on an internal "strike relay". If you have it, that might take care of this issue.

Rodeo, that is the lamphouse. I think the sensitivity control is for setting the autostrike. I do not use it and actually removed the relay a while ago. I maually strike it. And you are right it does absolutely nothing. When it does light after waiting it lights as easily as normal. Never have to hit it twice or "lay" on the button. My voltage prior to lighting is above 150 and it runs at 26. I think I can find an ignitor schematic but this ignitor is fully self contained. Some had spark gaps that could be accessed/changed.

I found the schematic. It's a pretty simple design... not much in there to go wrong. Assuming the obvious... that your manual strike switch hasn't worn out, and nothing looks overheated in the igniter, I guess I'd be heading toward that spark gap, too.

Jack

Hi,

I have been having this problem in one of my projectors. My tech told me it could be a bad diaode or a bulb that is going out. Now I read the book and it said if a bulb is cold it lights better the more warmer it is then sometimes it needs to send a pulse more than once to get the bulb to strike. So far I just give it a bit of time and it starts up.

If you have a bad diode, chances are that you'd be blowing circuit breakers.

That the system is trying to light eliminates quite a lot.

Some bulbs can be harder to ignite when hot, but I've always found that it indicates a problem elsewhere... usually low "no-load" voltage out of the rectifier or a weak igniter.

I'd check the no-load voltage first though. If you aren't absolutely sure what to do inside there, have a tech do this.

Hey, Editor...
Did you figure out what your problem was?

I am still running it in condition it was in before. Added 5 minutes between shows and if running tighter I leave it ignited and close damper. I think by accident I may have determined that the bulb is no good or marginal. Having trouble getting it lit one time I layed on the manual start button and after about 5 seconds the ignitor buzzed and bulb lit right up. I got the idea from ttroil post about Knisley. Also noticed that when blb is hot have lower quality light. It seems unstable. So will change out bulb before normal use and see what happens.