|
Author
|
Topic: Xenon lamp strike question
|
Claus Harding
Phenomenal Film Handler
Posts: 1149
From: Washington DC
Registered: Oct 2006
|
posted August 25, 2009 10:01 PM
I noticed on my Eiki 3500 that the 350W lamp seems to be more reluctant to 'hit' the first time if the lamp selector is on low, so I just wanted to throw this out there for anyone who has had issues (I was starting it on low to make the "hit" more gentle, but I may have used the wrong logic here.)
On the 'High' setting, it strikes cleanly the first time, and the lamp is obviously happier for that (as is my wallet), but I just wanted to know if any of the Eiki/Elmo owners have had any issues with this.
What are the power issues on an Eiki in terms of lamp strike voltage between 'high' and 'low' settings, if any, or is it an issue with the lamp and my ignorance of the above? Is the voltage the same regardless of the two settings when you first fire up?
The commercial machines I have run, you bang 'em on and there they are, so I just wanted to see if this had been an issue with anyone.
Thanks as always for any help you can offer.
Claus.
--------------------
"Why are there shots of deserts in a scene that's supposed to take place in Belgium during the winter?" (Review of 'Battle of the Bulge'.)
| IP: Logged
|
|
|
|
|
|
|
|
|
|
Claus Harding
Phenomenal Film Handler
Posts: 1149
From: Washington DC
Registered: Oct 2006
|
posted August 27, 2009 01:10 AM
Kevin,
The answer to that is that I don't know the age of the lamp, and neither did the seller.
I started using it, hoping for the best, and so far, it has performed without flickering during screenings. The start-up is the rough part now, on the low setting, but when I hit it on 'high' it comes on first strike, at least the last few times I did it.
I have a brand-new bulb from Superior Quartz, and if the one in the machine shows any reluctance firing 'high' it's time for it to go, and I am happy to have had the hours I had out of it.
A possible blown reflector (if it does indeed suddenly go) and cleaning the guts of the machine from minute glass splinters just is not worth the extra "value for the money." Nor is having to replace power supplies.
I appreciate the follow-up on this.
Claus.
--------------------
"Why are there shots of deserts in a scene that's supposed to take place in Belgium during the winter?" (Review of 'Battle of the Bulge'.)
| IP: Logged
|
|
John Whittle
Jedi Master Film Handler
Posts: 791
From: Northridge, CA USA
Registered: Jun 2003
|
posted August 27, 2009 10:44 AM
I've never seen one of these small Xenon lamps exploding (and thank heavens since I don't know where you'd get a new reflector).
But as you probably know, the Xenon lamp operates on a low voltage high amperage DC, normally around 22/24 volts. To strike the lamp, a spark has to jump the electrodes causing the gas to excite and then the arc starts. It's the starts that cause the electrodes to wear and pit making starting harder over time. With the higher voltages, the lamp starts more reliabily.
In the machines that leave the lamp on and use a douser (the change-over versions of the Eiki 6000/6100 and the CX series Elmo and others) the lamp automatically starts on high and then drops to a standby voltage.
On the portables that strike the lamp just before showing, it can be a bit tedious to strike on high and drop to low, I'd suggest putting in a douser so that you can strike the lamp at first start and then drop the lamp before showing the first frame.
Normally we look at the number of strikes before the arc starts as a sign of lamp age. While I've never done this, I would think if you example the lamp (in place and off) with a good magnifier, you'll see pitting on the electrodes compared to your new lamp.
John
| IP: Logged
|
|
|
|
|
|
|
UBBFriend: Email this page to someone!
Printer-friendly view of this topic
