Film-Tech Forum ARCHIVE: Xenon bulb must be manually struck

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Posted by Carey Barber (Member # 1586) on 06-04-2007, 12:49 PM:

Lamphouse is Christie SLC-45 (6000 watt)
Automation is Strong CNA-200

In one of my houses, the xenon bulb does not strike automatically when you press START.

It also will not strike when you flip the LAMP switch on the automation.

Every show, it must be struck using the MANUAL IGNITION switch on the actual lamphouse. When you hit this switch, it strikes the bulb fine (as if there is no problem at all).

I would suspect a bad connection involving the automation, as the ignitor seems to be OK and the bulb strikes fine from the lamphouse controls. It is the START button and the LAMP switch that are not working.

Does anyone have any tips as to where to look for a bad connection or any other suggestions as to why my bulb is not striking.

I have taken a quick look at the terminal board but don't see anything obvious. I will be taking a more careful look right now.

Thanks,
Carey

Posted by Sean McKinnon (Member # 612) on 06-04-2007, 01:39 PM:

well lets see... There is a relay in the big red and green box on the inside non projector threading side (the ignitor) you could replace that or else. You can change the Auto strike relay or the whole ignitor yourself if all the scary symbols on the ignitor scare you [Smile]

also... There is a resistor that you can adjust inside the ignitor too but that is a procedure best left to a tech.

This problem would have nothing to do with your automation or the power switch. just for curiosity how much no load voltage are you getting?

All the automation does is send 120 volts a/c through the safety (interlock) circuit (door switches, fan switches ect....) to the coil on the contactor in the power supply causing it to pull in and send the 3 legs of power to the power supply... The POWER switch just parallels that so if you can light the lamp you know that all of that is ok.

Posted by Michael Schaffer (Member # 1204) on 06-04-2007, 02:01 PM:

Just make sure all the breakers are off and wait a few minutes for the capacitor in the PS to discharge, verify with a multimeter across the DC terminals that there is no charge left (check for DC), then you can unplug the relay from the ignitor and exchange it with a new one or one from a known working unit. Chances are very good it's just the relay. That is a very typical symptom. As always, only do this if you are authorized to do it and if you understand every step and the components involved, how to check there is no charge left, etc. If not, call someone in who does. Good luck.

Posted by Carey Barber (Member # 1586) on 06-04-2007, 03:23 PM:

Thanks for the tips guys...
___________________________________________________________

The big question I have (and I am not sure if I made this clear in my original post) is why does the ignitor work fine and the bulb strike fine EVERY TIME when I use the manual ignition switch?

If there was a problem with the relay in the ignitor, wouldn't that affect ignition just the same whether I was going through the automation or striking it manually?

____________________________________________________________

I have swapped out ignitors several times in the past so that is not a problem, but I have never swapped out just the relay. What does this relay look like that your referring to?

I see two pieces that might be the relay -- one is solid black and the other has a clear case. They are labeled K1 and K2.

Which one of these parts is the relay you are referring to?

______________________________________________________________

Also, I forgot to mention that the contactor does 'click' when I press START or LAMP. Not sure if that would affect your diagnosis or not.

Thanks again...

Posted by Louis Bornwasser (Member # 3063) on 06-04-2007, 08:47 PM:

The clear case is the relay; the small black box is the time delay relay. Replace both and then put them back one-at-a-time to find which problem you have. Even if this isn't it, you are "close."

Repeating another: "What voltage is on the DC lines just before you puch the manual start?" Louis

Posted by Richard May (Member # 2627) on 06-04-2007, 09:25 PM:

Also, just to make it clear, when you turn the lamp switch on does the lamp light or do you then have to hit the manual strike button?

Posted by Sean McKinnon (Member # 612) on 06-04-2007, 09:35 PM:

I thought I explained that above...

The "manual" switch is parallel to the auto strike relay. If the relay doesn't operate, Pushing the manual strike does the same thing... The both close the circuit that sends 120vac to the igniter. BUT PLEASE PLEASE FOLLOW MICHEAL's INSTRUCTIONS OR YOU COULD INJURE or kill yourself!

When you Press "Start" on the Automation, or the "lamp" switch on the automation, or the "power" switch on the SLC Console 120vac are sent through all the door safety switches and the exhaust stack paddle switch then 20 a contactor which is simply put a big circuit breaker with a magnet that holds it closed allowing the 3 seperate 120vac ac lines on the seperate phases to pass through to some transformers, Capacitors, a diode bridge then to the lamp and -. The side goes through the ignitor just so that the igniter power and built up charge from the capacitors to end up at the (Anode) end of the lamp. There is a relay that momentarily closes sending a seperate 120vax feed to the igniter that turns the 120vac into 10-40,000 amperes to create a man made bolt of ilghting so to speak so that it can jump from one end of the bulb to the other. After that all that built up voltage in the capacitors follows behind it completeing the circuit and having a lit lamp!. Make any sense? Good explanation? That resistor I mentioned controls how long the igniters fires and if its set to too short a time you can have trouble lighting older lsmps.

If the info you have given is accurate the contactor is closing it has to be... U just may not be hear it click which IMO means you may be changin that out soon it would make me thing the coil "magnet" is getting weak (Man I need to read closer, lol I just re read and saw you said you can hear it)

Posted by Dave Macaulay (Member # 813) on 06-04-2007, 09:36 PM:

Auto ignitors all work pretty much the same. When the lamp is on, the lamp voltage is 25 volts DC or so. With the lamp not struck but the rectifier on, the voltage is quite a bit higher - 80 volts up to 150 volts depending on the type of rectifier.
The autostrike circuit just senses the higher voltage and tries to strike the lamp until the voltage drops which indicates the lamp is on.
Christie ignitors do it all in the ignitor case, older Strong systems have a separate autostrike circuit board. Different brands do it either way.
The voltage sensing circuit operates a relay to switch the AC power to the ignitor itself. Christie also has a time delay relay which stops the ignitor after a second or three and waits five or ten seconds before trying again, this prevents the ignitor from burning out. The high voltage transformer feeding the tesla coil circuit isn't designed for continuous operation, it would burn out pretty quickly if the ignitor didn't have the cool-down time imposed by the time delay unit.
Since your ignitor works on manual, the problem is with the autostrike part. The relay is most likely, the time delay less so, and the zener diode could have failed also.
Older ignitors have a time delay that looks a bit like a radio tube, in a socket. Newer ones use a black plastic box soldered in inside the case.
The nasty big warnings on the ignitor case cover are to tell you it can kill when it's powered. There's no danger in the ignitor if the AC supply is shut off, but there may be dangerous DC voltage on all the lamp wiring for a few minutes after shutting off if the rectifier was ON without the lamp striking.
DO NOT try bench testing the ignitor unless you really know what you're doing.

Posted by Sean McKinnon (Member # 612) on 06-04-2007, 09:43 PM:

Dave soome ignitors have small caps in them and the BIG ones in the power supple could discharge if he hit the + going into the ignitor and a ground! EDIT OOPS SORRY DAVE I DIDNT NOTICE YOU SAID THAT ALL I READ WAS THE AC PART!

Posted by Monte L Fullmer (Member # 2797) on 06-04-2007, 10:42 PM:

...you could take the cover off and readjust the slider on that wirewound resistor and then try to do an autostrike .. had to do that a few times to get one to autoignite.(AND still, watch out for those caps..they get kinda nasty if you get bit by one of them...

..those IGA15M ignitors are something else...had to replace a few of them.... and must make sure that you get the wiring placement correct, esp, the two wires that are crossed, for if you don't keep those crossed on replacement, that can easily take out an ignitor..

-Monte

Posted by Carey Barber (Member # 1586) on 06-05-2007, 11:14 AM:

Thanks again for all the input

___________________________________________

UPDATE--- I replaced the entire ignitor and the problem seems to be fixed. I struck the bulb multiple times.

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FYI - I swapped out the relay (the one in the clear case) and this did not change anything.

I was not able to swap out the black time delay relay because the design was quite a bit different between my two ignitors. They are both the same model #, so I guess Christie just changed their design over time.

Since I was not able to swap out both relays I went ahead and replaced the entire ignitor.

_____________________________________________________

Thanks again to everyone for taking the time to advise me.

I wish I would have had a better understanding of how the ignition process worked because I would have tried swapping out the ignitor a while ago.

Based on my limited (and apparently incorrect) understanding I thought that, since the bulb did ignite, the ignitor must be OK.

But, now I know, and knowing is half the battle!

Posted by Sean McKinnon (Member # 612) on 06-05-2007, 09:59 PM:

Well if the resistor is not set proprly it may not keep the ignitor on long enough... if it is adjusted to stay on to long then you hear that ZZZZZZZap noise and it can damage your lamps. Properly adjusted you should just bare;y hear a ping when the lamp ignites but only a trained tech should be adjusting the resistor. The less A/C across a lamp the better you want just enough to jump the gap and light the lamp.

Posted by Gordon McLeod (Member # 33) on 06-05-2007, 10:19 PM:

Many of those ignitors had a amprite timer that set a limit to the duration of ignition pulse

Posted by Monte L Fullmer (Member # 2797) on 06-06-2007, 01:45 AM:

(Yea Gord, like the little IGA10M ignitors having that AMRITE vacuum tube inside of them...I had to change out a couple of these tubes in a couple of old CH-10 Consoles)

Posted by Tim Reed (Member # 137) on 06-06-2007, 07:27 AM:

quote: Michael Schaffer
verify with a multimeter across the DC terminals that there is no charge left

I just touch the heat sinks real quick with my fingers. [Razz]

Posted by Mark Gulbrandsen (Member # 72) on 06-06-2007, 07:32 AM:

quote: Tim Reed
I just touch the heat sinks real quick with my fingers.

Truth revealed... now we know why that hairdoo is so odd [Eek!]

.

Mark

Posted by Michael Schaffer (Member # 1204) on 06-06-2007, 05:07 PM:

That's not a hairdo. I think it's a beaver cap, Daniel Boone style.

Of course, you can also use a screwdriver and short the DC terminals for a small light show, but for that, a screwdriver with an insulated handle is recommended, and generally, that is not the kind of tips we should be giving here. So don't try this at home!!!

Posted by Tim Reed (Member # 137) on 06-06-2007, 07:13 PM:

Only my hairdresser knows for sure! [Big Grin]

Posted by Louis Bornwasser (Member # 3063) on 06-06-2007, 08:26 PM:

Best light-show guaranteed only if 3-phase engaged. Louis