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Author Topic: Hard striking lamps Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 11-27-2010 05:55 AM                     This has been an ongoing problem and has gotten very tricky to figure out. Here is the set up. 2 Super Highlight II consoles. Consoles are only 8 years old. Very little use each year. November-December. 7000 watt xenons. Mostly in the morning when the lamps have cooled, the lamps have a hard time striking. The catch is, when the ignitor "zaps", it doesn't jump across the electrodes. It goes from the base of the cathode up to the ignition wire over the envelope. This was only happening on one machine. These ignitors are the DC version so they quickly pulse the lamps. Eventually they light and all is fine for the day. Now here is what we have done so far.....First we swapped lamps between the 2 machines. Problem stayed in the same machine. You would think it's the lamphouse then. So then we swapped ignitors. No good. Finally we put an old bulb in and it worked fine. So now it seems the bulb was bad. Fast forward to this year. We started the year with 2 new lamps as we do every year. We decided to switch from Osrams to ASL (for a number of reasons,the main one being that they advertise their lamps work well at extreme angles). By the 4th or 5th day, the same lamphouse is doing it again. So we start swapping again. We swap the lamps between the 2 machines and now BOTH lamphouses are doing it. So we start over again. Now I go back to the first machine that start this in the first place. I changed the cable from the ignitor to the lamp cathode. That seemed to work. A week goes by and perfect striking every day. So I decide to change the wire on the other lamphouse. The other morning I did it and now both of them are hard striking again. Go figure. So I took 2 old lamp and put them in both lamphouses and everything is fine. I spoke to Strong, Osram, and ASL and they all blamed it on the other companies.....as I figured they would. It really just seems that the newer bulb today suck. The older Osrams worked just fine here. The newer Osrams are the ones that gave us the problems. The ASL's also are giving us the problem. Strong did suggest that the AC ignitors would probably work better because they "really blast the bulb" as they put it. Btw way, starting volts are around 160VDC and amperage is 165A.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 11-27-2010 08:51 AM                        Experimentally, replace the capacitors in the power supply. "Low inrush current" could cause just what you describe and is typical on rarely used equipment. OK after first daily start, right? Capacitors are thought of as making the dc pure. They are also used to get the bulb lit. They become marginal with disuse. The 160v is no load, not running voltage, right? I do not have good data for ASL.. I sell a lot of Osram and have not had this experience with them. Are you buying the "XL" Osram or something lesser? Louis  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 11-27-2010 09:19 AM                     Yes, okay after first start 99% of the time. 160VDC no load. I'll replace caps next week.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-27-2010 09:39 AM                     I have many locations we just remove the ignition wire  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 11-27-2010 10:24 AM                     I have tried that also, but no change.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 11-27-2010 05:43 PM                     Is there anything stopping me from hooking up an AC ignitor in place of the DC one? I have a new ignitor that came from one of the ORC 6000 lamphouses here. Is it a matter of bringing 120VAC to a momentary switch in line with the transformer on the Ignitor?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 11-27-2010 09:25 PM                     Ignitors from STRONG (the white DC ones) are good for wanting to fail without notice.. I'd try the AC one since an igniter is an igniter. Changed the bulb to another one to see if it's the bulb issue?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-27-2010 10:20 PM                     if you ca see fly off the ignitor is doing its job look for the root cause  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 11-28-2010 06:41 AM                     I've been looking for the cause. These are 2 brand new bulbs. Also, one of the new bulb last year had the same issue. Like I said, I put an old bulb in and it works fine. So far, 3 out of 4 new bulbs are giving this problem.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 12-05-2010 11:44 AM                     Haven't gotten the caps yet. Even though we are getting more than enough starting volts, the caps can still cause this? Strong has had no answers for us on this problem. The latest is that we took the new bulb out of the master machine and put the one from 2 years ago in and it works fine every time. Now the slave machine with another new bulb is doing the same thing. First stiking in the morning just won't light. It took 10 minutes to get it lit. Again, it does not jump the gap but rather arcs to the ignition wire. Now the rest of the day it will strike immediately every time. I don't get it.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 12-05-2010 01:12 PM                     Yes Richard, the caps can still cause the problem. The caps store the voltage and help release it as a high CURRENT surge to get the bulb lit. To prove this, you can use a DC clamp-on amp meter With peak hold) on one of the leads from the cap bank. On ignition, you'll see a high-amperage spike (thus the need for a peak-hold meter) then the current will settle down to a fairly steady, low level. With good caps IIRC the "running" amps on the cap bank run around 5-10 amps. Marginal caps can still store a good no-load voltage, but they won't have enough capacity (pun intended) to supply the necessary current. Another factor: a lot of new bulbs are, as Joe would say, ass. Bulb manufacturers have been changing the construction and fill gases to either extend life or cut costs, but you are experiencing first hand the results of those changes. I no longer use Osrams of any style due to their poor performance of late. Christies have always proven reliable for me.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 12-05-2010 04:23 PM                     Thanks Tony. I totally agree about the bulbs. The problem is how do I go to the bulb company and say that. Nobody seems to want to take any responsibility. I'll try the new caps when they come in. If that doesn't work, I'll try replacing the DC ignitor with an AC ignitor.  |  IP: Logged Jonathan Bodge Film Handler Posts: 83 From: East Dorset, VT Registered: Nov 2006 posted 12-05-2010 08:34 PM                     I had this problem and bypassed the zener by striking the bulb as soon as I pressed the automation start. In other words instead of waiting for the voltage to rise to trigger autostrike I just banged it as soon as it was energized. This seemed to work after replacing almost everything. That damn inrush current. Kinda like surf.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 12-06-2010 07:11 AM                     With the DC ignitor, there is no manual strike.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 12-06-2010 11:51 AM                     That, and Jonathan's advice is very hard on the bulbs, rectifier and ignitors. Trying to strike before the rectifier has built up enough charge is counter-productive and WILL cause more wear on the bulb's electrodes. It also stresses the diode bank (or switching FETs in switchers) as they are now forced to provide the FULL surge of current to get the bulb lit. Capacitors in rectifers, regardless of type, serve two major purposes: one, to provide the voltage AND CURRENT boost to get the bulb struck, and second to smooth out any remaining AC ripple on the output of the diode bank (or from the switching FETs.) I do not recommend Jonathan's method unless you feel like replacing ignitors and diodes/switchers on a regular basis.  |  IP: Logged

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