My Kid turned off the projector

**Blaser** · **04-09-08, 03:49 PM**

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

Now I have to wait about one hour just not to be hard on the bulb. What would you do?
- Kill the baby?

and face the mother?

- buy a standby projector?

- 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!

**Barney Fife** · **04-09-08, 04:13 PM**

I choose none of the above. I wouldn't let the baby play with the remote.

**Blaser** · **04-09-08, 04:28 PM**

Hey Barney!

I was pretty sure someone would say this

. I am also pretty sure you may have no kids yet... They can be very hard dealing with!

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!

**lcaillo** · **04-09-08, 04:45 PM**

Quote:

blaser wrote:

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

Now I have to wait about one hour just not to be hard on the bulb. What would you do?
- Kill the baby?

and face the mother?

- buy a standby projector?

- 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.

**tonyvdb** · **04-09-08, 05:04 PM**

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.

**thewire** · **04-09-08, 05:45 PM**

surfacedeskisland.jpg

After you have watched the movie so as to not spoil it for you, here are goofs to chear ya up afterwards.

http://www.imdb.com/title/tt0399201/goofs

**Blaser** · **04-09-08, 05:59 PM**

Quote:

lcaillo wrote:

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.

**Blaser** · **04-09-08, 06:01 PM**

Quote:

thewire wrote:

Attachment 7115

After you have watched the movie so as to not spoil it for you, here are goofs to chear ya up afterwards.

http://www.imdb.com/title/tt0399201/goofs

Hey Thanks!

**Prof.** · **04-09-08, 06:29 PM**

Ahmed..You did the right thing by not turning it back on again.

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..

**Blaser** · **04-09-08, 06:50 PM**

Yeah that's what I'm talking about...But once in a lifetime won't kill though

**lcaillo** · **04-09-08, 06:54 PM**

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.

**Blaser** · **04-09-08, 07:04 PM**

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

.....

**Prof.** · **04-09-08, 08:12 PM**

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..

**lcaillo** · **04-09-08, 08:39 PM**

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.

**alan monro** · **04-10-08, 01:51 AM**

Definately, kill the kid. lol
Alan Monro

**thxgoon** · **04-10-08, 12:16 PM**

Quote:

lcaillo wrote:

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.

**tonyvdb** · **04-10-08, 01:20 PM**

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

**lcaillo** · **04-10-08, 01:49 PM**

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.

**Barney Fife** · **04-10-08, 08:55 PM**

Quote:

blaser wrote:

Hey Barney!

I was pretty sure someone would say this

. I am also pretty sure you may have no kids yet... They can be very hard dealing with!

Actually, Thelma Lou and I have 3 kids.

**Blaser** · **04-16-08, 07:27 AM**

Well... It was a missed shot

**Danny** · **04-16-08, 11:22 PM**

Most of the damage to the lamp is caused when it is struck. This is because to strike a lamp it requires a high voltage electrical discharge across the electrodes followed by an extremely short period of boost current. This boost current is approximately 3 times the rated lamp current, this is what causes the most damage to the lamp as the electrodes are still cold when this current is pushed through them. (Cold is defined as anything longer than a few seconds). The best lamp lifetime will be achieved if it is struck once and left on, of course for this application it is not a viable option, but if you have been watching a movie and you need to go out it is better to leave the lamp on if you will be back within hour. I have a lamp failure analysis on my computer i'll see if i can find it and upload

**Blaser** · **04-18-08, 04:47 PM**

What you say is true. Nevertheless, the impact will not be fatal if this is done only few times in a bulb lifetime.

Waiting for that lamp failure analysis

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