Film-Tech Forum ARCHIVE: Xenon Life

This is topic Xenon Life in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Ian Bailey (Member # 1752) on 06-20-2006, 03:04 AM:

I have 2 sites that have identical lamp houses(Strong SuperLumex & Strong Lumex)but with different rectifiers.One site regularly gets 3-4000 hrs out of a xenon and the other site usually gets between 1500-2000 hrs.I know I have to have a closer look at the exhaust system at the site that gets the lesser hours but what else do I need to look for to try and improve the life of the lamps?
Cheers
Ian

Posted by John Pytlak (Member # 331) on 06-20-2006, 06:59 AM:

In addition to improper cooling of the lamps, excessive AC ripple in a power supply could also cause premature aging of a lamp. Usual sign is excessive erosion of the internal electrodes of the lamp, leading to ignition difficulties. Don't forget to check ammeter calibration -- you may be unknowingly overdriving a lamp if the calibration is off.

Posted by Steve Scott (Member # 630) on 06-20-2006, 11:44 AM:

We have a hodgepodge of Strong power supplies, to varying degrees of performance as well. Which PS's are these in particular?

Posted by Ian Bailey (Member # 1752) on 06-21-2006, 01:00 AM:

Scott-the rectifiers are IREM,Strong Switching Rectifier,just can't remember the other brand.

To Check for RIPPLE-I'd assume you would check it with a Digital Voltmeter on AC MILLIVOLTS across the two cables going from the rectifier to the lamphouse(at the rectifier end)-CORRECT??
What is the acceptable level of ripple?
If the ripple level is not acceptable is it just a matter of changing the capacitors in the rectifier?

To Check Ammeter calibration- I'd assume you use a good quality clamp meter to check the DC current-CORRECT??
Could someone verify that I'm heading in the right direction!
Cheers
Ian

[ 06-21-2006, 08:02 AM: Message edited by: Ian Bailey ]

Posted by Richard Fowler (Member # 893) on 06-21-2006, 11:44 AM:

IREM tend to have higher ripple.

Posted by John Pytlak (Member # 331) on 06-21-2006, 02:36 PM:

This OSRAM techical publication has a very good discussion of current ripple and how to measure it, starting on page 17:

Osram XBO Theatre Lamp Technical Manual

Posted by Mark Gulbrandsen (Member # 72) on 06-21-2006, 05:36 PM:

quote: Richard Fowler
IREM tend to have higher ripple.

I've measured many rectifiers over the years...
Irem 3 phase.. 2kw and up...10 to 12%

Irem Single Phase Up to 1.6kw... 6 to 8%

Christie 3 phase. All typically 5% to 6%

Kneisley 3 Phase... 5% to 8%

Kneisley Single Phase typically 4%

Strong 61000 High Reactance Series...almost to high to mention but typically above 10% to as high as 14% All but Strong 61000 Series have inrush corrent with in manufacturers limits.

Mark
(Live from Mike Blakesley's Auto PArts Store!)

Posted by Ian Bailey (Member # 1752) on 06-22-2006, 05:46 AM:

Mark-so what you are saying is rectifiers can put out up to 14% ripple- so it could be putting out a lot of ripple but still be in good working condition?? How much ripple is needed to start looking at ways of reducing it??
Also can a good quality clamp meter be used to check the current going to the Xenon?
Ian

Posted by Louis Bornwasser (Member # 3063) on 06-22-2006, 09:01 AM:

I get really good bulb life with IREM rectifiers. IREM rectifiers have high ripple: therefore ripple must be GOOD?

There is obviously more to this story than ripple.

Many "electronic" rectifiers have low or no ripple but very bad bulb life. Louis

Posted by Ian Bailey (Member # 1752) on 06-22-2006, 10:21 AM:

Thanks for the link John,now I understand how to measure ripple.
Louis-Thanks for clearing that up [Eek!]