While gather parts for my projector, among the list was on 500watt halogen lamp, upon firing it up I was amazed at how much heat it produced, paper would just spontaniously combust when put near it, thats hot! - i knew this was gonna be too much for the LCD to handle for sure, even at distance so I looked for a solution, ive read abit about these IR Reflectors but couldnt find anything locally, so in my search I found out that water absorbs a lot of IR energy, So heres what I tried:
After reading through a few posts, people have mentioned that
water absorbs IR heat etc. So I pondered on this, rocked on down to the local glass place and had two peice of class just larger than my lcd screen cut to size (cost, $6nz about 4$US including glass etc) got some rtv silicon and sealed the two glass plates togeither with as much space as possible, used a seringe to inject water into it and i filled it with water ( bout a 8mm gap between the glass ) ... now this was fine it cut down the heat by atleast half.. but after a while the glass and water became to hot to touch and basically become pointless..
How to solve this? two prongs rtved in, a pump and a small radiator, and a very very quiet fan(inaudable)
this works perfectly! - basically theres no heat on the other side of the glass(this is with a 500watt Halogen), whereas before I couldnt hold my hand anywhere near it. This solution does cut down a little bit of light, my guess would be somewhere in the vicinity of 10% perhaps less.
This is a very viable solution and I will be including it in my design.
What are some peoples comments on this idea? water in the system is one issue yes, however im sure you could make it pretty damn safe, the bulb would really be the only high voltage item in the system, at 240v(here in NZ) and most lcd's run on 12v.. lamp would be above the bottem of the box and sealed in a metal case with a condensor so its not really a issue either.
After reading through a few posts, people have mentioned that
water absorbs IR heat etc. So I pondered on this, rocked on down to the local glass place and had two peice of class just larger than my lcd screen cut to size (cost, $6nz about 4$US including glass etc) got some rtv silicon and sealed the two glass plates togeither with as much space as possible, used a seringe to inject water into it and i filled it with water ( bout a 8mm gap between the glass ) ... now this was fine it cut down the heat by atleast half.. but after a while the glass and water became to hot to touch and basically become pointless..
How to solve this? two prongs rtved in, a pump and a small radiator, and a very very quiet fan(inaudable)
this works perfectly! - basically theres no heat on the other side of the glass(this is with a 500watt Halogen), whereas before I couldnt hold my hand anywhere near it. This solution does cut down a little bit of light, my guess would be somewhere in the vicinity of 10% perhaps less.
This is a very viable solution and I will be including it in my design.
What are some peoples comments on this idea? water in the system is one issue yes, however im sure you could make it pretty damn safe, the bulb would really be the only high voltage item in the system, at 240v(here in NZ) and most lcd's run on 12v.. lamp would be above the bottem of the box and sealed in a metal case with a condensor so its not really a issue either.
u would want to use distilled water and seal the system up so that algae or something doesn't bloom inside...
Well all i can say is that you have stolen one of my future ideas lol, except mines slightly diff. You will need anti fungal inhibitants aswell as distilled water to cut back mould, corrosion ect.
Ill make mine up soon and show you what i did.
Trev
Ill make mine up soon and show you what i did.
Trev
SAFETY WARNING!!!
Make sure any system that mixes water and electricity has a Residual (or Earth Loop) Current Circuit Breaker. Dampness and voltage do not mix even slightly...:
try to use all plastic or silicon tubing and couplers...might not want to see corrosion flowing inside the darn thing...haha...anit-fungal...that's a real cool idea...another way would be to get those liquid that they place inside projection TVs...wun they work good??
Is their any optical abberations near the high flow areas?
I thought you may get some rippling if the density changes near the in/out flows were too high.
Q.
I thought you may get some rippling if the density changes near the in/out flows were too high.
Q.
it doesnt even need to pump, the syphon effect of the heat transfering through the water is enough so it seems, (heat flowing through the water so to speak) but with the pump on there is no noticable swirls, just need to make sure theres no bubbles and the like, other than that it works just fine
If the lamp give also a lot of UV(c) radiation I wouldn't worry to much for algae or fungi. UVc will kill any micro-organism and they are used in water treatment plants.
hmmm looks cool...and seems good in theory...is the "convecion" thingy that "bad" as in enough to move the liquid around the radiator and stuff?? which means the radiator must be below the glass pieces then...
UV - C kills anything thats bio-organic, thats why it kills your lcd lol, the colour pigments and the polarisers are bio-organic.
Trev
wouldn't a filter be able to filter that out?? But then...perhaps the hassle involved might put some off using halogens...the cloour too...
theres seems to be very little difference in color, on the projected image from my experience with a Halogen OHP and a commercial LCD projector
Yes, the convection 'thingi' works perfectly, however a little wee very slow pumping pump would be good to make sure its workin as it should.
I dont think UV is just an issue with halogen at all, I thought MH setups actaully produced more UV and IR than halogen? - in which case it doesnt matter which route you take you are going to have to do something about it, however halogen wont be as bad, but it wont be as bright and it will cost you more to run, cause its not as efficient.
Yes, the convection 'thingi' works perfectly, however a little wee very slow pumping pump would be good to make sure its workin as it should.
I dont think UV is just an issue with halogen at all, I thought MH setups actaully produced more UV and IR than halogen? - in which case it doesnt matter which route you take you are going to have to do something about it, however halogen wont be as bad, but it wont be as bright and it will cost you more to run, cause its not as efficient.
If a plasma light source hasn't got an UV-block it will give more uv than halogen. I don't think it produces more ir-radiation becauce plasma is more efficient so less heat, less ir.
I like the idea of natural convection. Maybe include a flow meter which controls a pump. I'm currently working on a class a amplifier completely submerged in sunflower oil in a plexiglass tube and a radiator. It's almost ready for the first test with oil.
I like the idea of natural convection. Maybe include a flow meter which controls a pump. I'm currently working on a class a amplifier completely submerged in sunflower oil in a plexiglass tube and a radiator. It's almost ready for the first test with oil.
The idea about the Amplifier is somewhat interesting but I could probebly save you a great deal of time having had a Watercooled and Phase Change (-25c full load temp) PC.. Oil is not very conductive so to speak it is very hard to pump and the convection idea probebly wont work so well with oil.. Brillant solution to your problem would be a standard Waterblock designed for a CPU and a small radiator and Pump, would be 10 times superior, Im not knocking your idea as I have not tried and I could be wrong, just my view on it
Basically your Amp IC strapped to one of these if you get my drift.
http://www.hard-h2o.com/hardh2o.php.../engreviews/watercooling/cpublock-oclabs.html
Water flows through a milled out path in the block.. these happily keep CPU's that put out 100watts of heat at a few degrees above room temperature with a decent radiaitor.
However, this is not the cheapest route, coming in at around $50US for a suitable Waterblock, which may be what your looking for (a cheaper solution)
If the oil heats up a little bit it will probable become more liquid. But I already had in mind to use big tubes (about 1").
Large power transformers are cooled the same way, but there the oil also gives electrical isolation.
Large power transformers are cooled the same way, but there the oil also gives electrical isolation.
yes I believe its a way to conduct heat from the parts of the transformer that are live while maintaining electrical isolation, to the outside fins(where the heat is effectivly removed via air converction).. they generally use a standard type of oil similer to engine oil
Will sure be interesting to see how its turns out, do let us know.
Will sure be interesting to see how its turns out, do let us know.
the worst that could happen, beside possible electricution because of leaks, is that if your pump develop bubbles or, if your not using distilled water, the water calcifies on the glass and tubes/piping.
Indeed, some of them also use an external radiator.
Most transformers use something like shell diala. In some countries they use sunflower/peanut/palm oil. My first plan was to use silicon oil, but it's insanely expensive.
Most transformers use something like shell diala. In some countries they use sunflower/peanut/palm oil. My first plan was to use silicon oil, but it's insanely expensive.
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