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Discussion Starter · #1 ·
Submitted for your approval a picture of a dila bulb

at 1400 hours. Notice the etching away of the reflector

near the base of the bottom electrode. Not quite

viewable in this picture is the stress crack at about

8 oclock. This bulb no longer starts reliably. I would

say the brightness is down to about 50%. I'm going to

put this on a seperate power supply, and run it till

it either quits or explodes. My guess is about another

200 hours.


http://gilmore.chem.nwu.edu/dilabulb.jpg


Photographed on an olympus dp10 and olympus microscope.

Getting the focus right is tough, the saphire front glass

confuses the camera.


[This message has been edited by kevin gilmore (edited 05-21-2001).]
 

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Kevin,


Neat picture. At what hour did you take the bulb out of service? At 1000 to 1300 hrs., did you notice a drop in light output?


Chris
 

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Discussion Starter · #4 ·
1397 hours to be exact. The last 100 hours i definitely

noticed a dropoff. But not as much as i expected.

However, put in a new bulb, and oh boy what a difference.


The perkin elmer web site talks about the striking

of the lamp and how that effects the reflector. I think

they are not kidding. So lots of low hour usage is

much worse on the bulb than more extended usage.
 

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Kevin, do they mention a '# strikes' rating as well? For some reason I have the number 500 in my mind from some posting a while back (ie rated for 500 strikes), but confirmation would be nice. If this is the case then basically you should keep the projector on for at least 2 hours at a go.


Andy K.
 

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Discussion Starter · #7 ·
There is nothing about the amount of strikes on the

perkin elmer web page, but it certainly makes sense.

I certainly use my projector in smaller increments

than i should, and i still got 1400 hours.



I put the picture on my personal web server.

(so nice to have my own machine on an ATM line)


then i do the following (replace curly brackets with square)

(and take the spaces out of the h t t p)

{img}h t t p:// gilmore.chem.nwu.edu/dilabulb.jpg {/img}




[This message has been edited by kevin gilmore (edited 05-22-2001).]
 

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So, with smaller interval runs, you were able to go to 1400 hours before noticing that the picture was starting to go.


I know that Disney with longer (day long) runs of the projector go to 2000+ hours before changing their D-ILA bulbs.


There definitely seems to be more to lamp life than just "hours".
 

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Hi Chris,


No problem. Only if Dilard is doing the automation, though. The projector doesn't store the strike data.


Here is a neat trick...the lamp time is both readable as well as writable. I wonder if it might be more accurate to come up with our own way of determining when it is time to change the bulb:

Lamp Hours + (Lamp Strikes * .5) < 1800c>


This equation counts turning the lamp on as the equivalent of 30 minutes of running the lamp, and then changes the threshold to something that is probably a little more accurate reflection of the reasonable life of the lamp.


When you get to 1800 on the counter, your time is up.


Good idea...but I'm up to my elbows in this (very cool) calibration stuff right now. It's really coming along great!
 

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My G11 typically runs for extended periods of time. As I stated awhile back, I made the mistake of turning the family room into the HT. As a result, the G11 has become the "TV" of choice in the family. (The wife's reasoning: "If I'm gonna let you spend 10-15K on all that 'stuff' then, dammit, I'm watching my soaps on it"!)


Has anyone ever seen General Hospital, recorded to a 10 year old VHS tape via a little 13" combo, and a god-awful cable service, projected through a G11 with only the internal scaler...? I just don't know how she does it.


Anyhow, to make a short story long, I replaced the bulb at about 2100 hours... Yup... 2100! I never had a miss-fire on lamp startup and after all the hype about how bright the image would be after bulb replacement, I was amazed at how little things changed. I still wonder how much longer I could have run the old bulb. If I were not aware of the possibility of exploding the bulb, it would probably still be running.


How many strikes per weeks? I'd have to say about 6 to 10. But, once on, the poor little thing runs for hours! 4 to 6 per evening, I'd say. Luckily, its rarely used on the weekends during summer.


Man I wish these bulbs were cheaper!!! I had no idea I'd (they'd) be putting these kinds of hours on my poor little G11.


------------------

Never underestimate the importance of Duct Tape and RTV
 

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Monsoon,


That's very interesting. We have a few commercial installs with DILA's in them and have noticed similar results. While occasionally, they'll start misfiring around 1200 hrs or so, there's times when the lamp will run fine for nearly 2000 HRS before we replace it for safety's sake. These PJ's I'm refering to are fired up once a day and run for approx 16 hrs each day.


Mike
 

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Quote:
I replaced the bulb at about 2100 hours... Yup... 2100
Interesting. Both of the last 2 posts indicated that the projector ran fine to 2000 hours...and both times the bulb was replaced "for safety's sake".


While I am planning on doing the same thing (replacing at ~2000 hours regardless), I do wonder how far the bulbs can go.
 

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 This has already been posted several times in this forum(once by me but I did not discover it), but if some of you guys never saw it, it should make your day.


------------------

Robert
 

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Yeah,


I got a good chuckle out of that a while back. Although, I sometimes wonder if we wouldn't be better off going back to those 19" black and whites.... I suspect the kids might be better behaved at least, and I KNOW I'd weigh less!!


Mike
 

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Discussion Starter · #18 ·
I now have the bulb on a perkin-elmer power supply

trimmed to 420 watts, with an hour timer on it. Shoved

into a corner where its not going to bother anyone. Going

to run it 24 hours a day until it quits or explodes

(or implodes more likely)


My opinion at this point is that the saphire front window

will not crack ever, and the rest of the bulb is so

buried in the heatsink that damage to the projector

if it was still in one would be highly unlikely.
 

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Hay Kevin,


Would you like me to send you my 2100 hour bulb. Its been freed from it's heatsink... handled with all kinds of skin oils and household dust...


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Never underestimate the importance of Duct Tape and RTV
 
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