30ºC is OK for the lilliput?

[gstuder]

Hi all: Yesterday I made some tests. I turn on my light engine (Osram HQI-TS/NDL 150W plus a commercial reflector).

I made a wood box tunnel for the ligh path (thin wood, 2 mm) of 16cm long x 17cm wide and 13cm tall

At 11cm from the light I have a Glass and at both sides of the box I have two coolers, one blow air in the box and the other push it out.

The glas divide in two the circled windows in both lateral faces of the box. (I dont know If I'm describing it well)

Well, I measured the temp in the opossite end of the box (Where the Fresnels should be placed) and I red 30ºC degrees (Sorry, I dont remember how to translate ii to Kelvin)

My Queestions are:

Is that temp. OK for the LCD? (Assuming that the LCD andthe fresnel will have the same temp)

It's correct that the LCD would has the same temp. that the Fresnel ? The thing that carries me to this question is that the fresnel in my design is being cooled by the fans, but the LCD will not be "touched" by the air that exsaust the air out of the box.


A final question would be: Wich temp the lilliput can mange ?

Thank you for your answer.

[spectreag]

gstuder,

Just to let you know, 30 degrees celcius is 86 F and 303 K. If you need kelvin add degrees C with 273, and this will give you Kelvin.

ex: 30 C + 273= 303K

To get temp in F, Use the equation: F= (9/5 * C )+ 32.

I am also wondering about temp ranges. I am getting ready to build my light engine, so when I get to testing I will let you know about my test results if you still need them. Good luck.

[rcabezas]

Where did you measure the temp? Be aware that if there is nothing absorbing the light (clear glass won't), then temp will stay down. Then, when you add the LCD, it will absorb lots of the IR and heat will build up.
I have probs with temp and my lilli right now, I'm thinking about using a hot mirror or a cold mirror...

Raf.

BTW, 30deg celcius is more than OK for the lilli, if it will in fact stay at that temp. But IR will bring it up once you put it in.

[gstuder]

Thank you Spectreag for remembering me the formulas !!!!

[gstuder]

Rcabezas

A fan dedicated only to cool the lilli would work? I bought a 8" Sunon that moves a los of air. Its quite big but I'm afraid tha it could help to keep the lilli warm

When you have the reading please post them.

Thank you

[rcabezas]

Reading of the temperature? I don't have a thermometer, what are you using?
I am using a 80mm fan right now, and it keeps the light channel cool, including the fresnels and a glass I have, but the IR goes right through all that, and heats up the LCD so that it gets too hot to even touch. I just bought a hot mirror from surplusshed, I'll let you know how that goes..

Raf.

[gstuder]

Sorry, i mistake the units !!!!

The fan is 120 mm !!!!

Although the LCD is hot it's keep working? It doesn't have a protection? It doesn't turn off or start to have errors?

I was thinking on going to an electronic parts retailer and buy some bimetal (a switch that opens or closes its contacts at a rated temp) to turn off the LCD and Light engine in case the Temp go over a level.

That could be a good idea in order to protect a projector that today is running ok (Ace's, I eat Flowers', Bernardo's) but that one day a fun could stop unespectely.

What do you think? It could help us when we're exerimenting.

Bye

[rcabezas]

That's an idea, you would need to run a relay and the light with it.
Another solution would be to use the combined yellow cables from all the fans through a PIC micro or something and decide what to do if they stop. I'm also thinking about using it to turn them on and off on power up/down; and also to control when to turn the bulb on and off.
(ie, the bulb should never be turned off too early during the start up, as that decreases the life of the bulb by a lot);.

But, yes, the LCD keeps running even though it's hot, and so far nothing bad has happened, but I don't want to keep running it under these conditions...

Raf.