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Discussion Starter · #1 ·
I was watching the Island (for the first time) and right after 20 min my 1.5 year old daughter playing with the remote control turned off the projector :gah:
Now I have to wait about one hour just not to be hard on the bulb. What would you do?
- Kill the baby? :devil: and face the mother?:hide:
- buy a standby projector? :spend:
- Turn it on immediately after the short cool down period

Well, I chose none of the above, I preferred to come home and say hello to everybody! :wave:
 

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Discussion Starter · #3 ·
Hey Barney!

I was pretty sure someone would say this :R. I am also pretty sure you may have no kids yet... They can be very hard dealing with!:raped:

But you're right... Sure I will hide that remote next time, but my problem is I like to play a lot with it myself! :heehee:
 

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I was watching the Island (for the first time) and right after 20 min my 1.5 year old daughter playing with the remote control turned off the projector :gah:
Now I have to wait about one hour just not to be hard on the bulb. What would you do?
- Kill the baby? :devil: and face the mother?:hide:
- buy a standby projector? :spend:
- Turn it on immediately after the short cool down period
The projector has thermal protection that keeps you from starting the lamp while it is too hot. You will not do any damage to the lamp by restarting it without waiting an hour.
 

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You think thats something to worry about, a few months ago my wife whom I love dearly accidentally turned off the power kill switch on the back (this kills the fan as well as the bulb immediately) as she was unaware that you had to use the button on the bottom of it so it had no cool down, That concerned me but so far this doesn't seem to have affected it at all.
 

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Discussion Starter · #7 ·
The projector has thermal protection that keeps you from starting the lamp while it is too hot. You will not do any damage to the lamp by restarting it without waiting an hour.
Hi Icaillo,

Yeah I know. In the manual the cooling down time is few second if memory serves. This topic has been debated few times and there was no clear winner. Of course I understand it won't do any harm specially if it is not a habit to do so.
 

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Discussion Starter · #8 ·

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Ahmed..You did the right thing by not turning it back on again.:T
I have been told that you shouldn't turn the projector back on again for about an hour, when there has been no fan cool down..
Even when the fan runs it's cause and switches off after the prescribed period, the lamp is still warm..and turnig it back on again immediately only aids in reducing the life of the lamp..
 

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Discussion Starter · #10 ·
Yeah that's what I'm talking about...But once in a lifetime won't kill though :)
 

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Any additional aging of the lamp is far more due to the act of starting it regardless of whether it is warm or not. The whole matter is seriously over-stated. I have had repeated discussions of this issue and that of power down cooling with engineers from various manufactuers and Osram and Philips, and my conclusion is that the number of start cycles is FAR more significant than post power cooling. You do not want to start a hot lamp, true, but the temp drops so fast once the arc is extinguished that you won't hurt the lamp after a couple of minutes, with or without fans. Once the thermal sensor in the set allows restart, it is perfectly safe to do so.
 

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Discussion Starter · #12 ·
I tend to agree with you. Personally, I don't believe it would be that hard on the lamp to the point to considerably reduce its lifetime (if restarted few times quickly), nevertheless I just like to be extra careful, specially when nothing's so urgent. Should I have been in the mood of turning it back on immediately, I would have.... regardless of the impact on the bulb anyway. I know, I am sometimes hard to understand :coocoo:..... :bigsmile:
 

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If the power is suddenly cut to the fan, extinguishing the lamp without any cooling, the glass envelope can expand and distort quite rapidly..even to the point of forming a bubble..
If the distortion of the envelope is not allowed to return to it's original state, by a natural cooling down process,(contraction) the distortion will remain if the lamp is turned back on again..
If this happens several times, the lamp can actually blow..or at the least, reduce the life of the lamp.
If the lamp hasn't had any cooling from the fan.. as in the normal cool down process..It generally takes about an hour to get back to the cold state..when it's safe to turn it back on again..

I personally would not like to take any risk by turning it on any sooner..
 

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This is largely myth. The concern is that there may be some thermal lag if there is not continuous air flow during shutdown. According to engineers for the companies that make the lamps, it is a minor issue and likely only going to occur in some of the highest power lamps in the most compact projectors, though they have never confirmed it. Once current flow ceases, the arc extinguishes immediately and no further heat is generated. The notion of the formation of a bubble is unlikely. The glass eventually devitrifies, but this is not seriously affected by these matters.
 

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This is largely myth. The concern is that there may be some thermal lag if there is not continuous air flow during shutdown. According to engineers for the companies that make the lamps, it is a minor issue and likely only going to occur in some of the highest power lamps in the most compact projectors, though they have never confirmed it. Once current flow ceases, the arc extinguishes immediately and no further heat is generated. The notion of the formation of a bubble is unlikely. The glass eventually devitrifies, but this is not seriously affected by these matters.
Interesting Icaillo. You seem to know more on this matter than anyone I've spoken with. You wouldn't happen to know the exact physics of what causes the lamps to blow or how they 'age' would you? I've always wondered.
 

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I also thank you Leonard, your wealth of information is invaluable on this forum.:clap:
 

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You are very much welcome.

The aging of the lamp has a couple of components. The preferred way for them to age out is the gradual deterioration of the electrodes, which have a very tight tolerance in spacing. As they lose material, the gap gets larger and the shape changes, and the ability to strike an arc and sustain it degrades. There is also devitrification in the glass envelope. If this occurs to early in the lamp's life, the glass envelope can break and you get a somewhat messy failure, before the electrode loses its ability to create the arc.
 

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Discussion Starter · #20 ·
Well... It was a missed shot :joke:
 
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