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This topic comprises 2 pages: 1 2
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Author
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Topic: Christie ignitor failure - where to start?
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Craig Huegen
Film Handler
Posts: 24
From: Bartelso, IL, US
Registered: May 2013
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posted 06-17-2013 10:07 PM
I have a Christie CH10 lamphouse (part of that hobby implementation I spoke of) that has an IGA10M ignitor in it, which will no longer strike.
We have 120V to the lamphouse, but no buzz with manual strike button and no autostrike. I can see a tiny flash / arc inside the manual strike switch itself when I push the button, so I can see there is power to the ignitor.
Just minutes earlier, it struck fine.
Before I take things apart, I'm here to collect ideas on what is likely wrong and any tips. From what I read here and in other places, my educated guess is the relay or HV transformer.
As I understand it, the relay case is clear so I can see whether it's pulling properly when the button is pushed -- if the relay appears to work, suspect the HV transformer.
Sound about right? Any other places you'd look, given those symptoms?
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Dave Macaulay
Film God
Posts: 2321
From: Toronto, Canada
Registered: Apr 2001
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posted 06-18-2013 10:29 AM
First of all you have to be very fricking careful. 120V line power can kill you but generally just gives you a jolt to remind you not to touch it. The ignitor HV is more likely to just kill you. Checking the HV transformer with an ohmmeter is the first step (no AC power connected!), the primary should be fairly low resistance - under 100 ohms probably, and the HV side should be fairly high - 10K at least as a guess? Neither side should have any continuity to ground. The Christie ignitors are a bit different than others, they use a delay device to limit strike time to avoid burning out the HV transformer. This delay device can fail, that either disables the ignitor or disables the protection. Check the delay device. The contact layout should be printed on its case, check for continuity between the power and load terminals. Testing this delay under power is a bit risky - I do not like to have meter probes on things in there if the HV can potentially turn on. Disconnect one HV transformer primary wire and check for line voltage on the transformer's supply terminals (where you disconnected it from) with the ignitor powered and activated. The spark gap is pretty foolproof but may be a problem. You can clean the spark gap contacts I think, note the electrode spacing and get it back the same when done if you disassemble it. The capacitor is pretty much indestructible. You can test the HV transformer if you have a variac supply. If you connect the line side to the variac output and meter the HV output, applying a volt or three on the input will give a measurable but not destructive output voltage. Any normal voltmeter will be destroyed if you try to measure the output at full line voltage input, you would need a special set of HV probes. It's possible for the transformer to arc internally at operating voltage but seem fine at lower voltage, so the variac test doesn't prove the transformer is OK. If you find and fix a problem and want to test the complete ignitor: you must provide a reasonable spark gap at the output studs. Without an external arc path the arc will be somewhere inside the unit, and probably damage something. Use wire stiff enough to hold its shape, I use 14ga solid wire from whatever old electrical cable is lying around or coat hanger wire. Wrap a length around each of the studs and secure with the nuts. bend the wires so the ends point together about 1/2 inch apart, when testing you should see a bright hot spark arcing between them. If the delay device is working, the ignitor will shut itself off after a second or two of arcing, then come back on for a second or so every 5 or 10 seconds. Don't be too close to the unit under test.
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