LED is the future, anyone want to start experimenting?

[jtbullet]

I am hoping to put my lilliput to use this year. I am hoping to build an led solution. I realize that it will be difficult, but I know that in the long run the benefit will be big.

1. No heat = smaller unit = no fan = quiet
2. 20,000 hour life = 10 normal projector bulbs = 2000$ - $3000 savings

The problems to be addressed, as I am a newbie, are what are my realistic goals as far as number of lights, appropriate driver for the decided upon number, and achieving a good cost versus performance ratio for the leds. Also, combining the lights to give a crisp image. Can we start a thread where we collect knowledge on the diy LED progress? I know there are german forums, but i think we need a translator for accurate information. Anyone wanting to help or add to this, please contact me. I am planning on buying a 2.5" lilliput for experimentation, but I think the actual light output from a lilliput 7" will be better, because there is a larger image area to put leds behind. I dont think I can get more than a few behind a 2.5 ", but someone said they got 21 behind a 5".

I am ready to start purchasing leds and driver, but i need some advice as far as buying a driver that will be suitable on both the small number of leds behind the 2.5 inch as well as the larger behind the 7". Ace has suggested that each light needs a guide, and I take this to mean the snap on colimators. Please contribute to this thread, we all know leds are the future of light sources, and an industry insider tells me the projection industry's biggest fear is the bulb companies going under, and they seem to think this isn't too far away. I think we have the best collection of forward thinkers here, at least for this field, and I think that a useable diy led must be a possibility, or even a laser for that matter.

[jtbullet]

First off, I am putting in some links to LED manufacturers:

http://www.luxeonstar.com

http://www.lumileds.com

please feel free to add more.

[dwalls32]

To me it seems odd that we would want to have an "array" of lights making a flat field of seperate points of light hitting different points of a fresnel or lcd panel, as that would just make it harder to focus etc.

What is the possibility of making each of the led's aim at the exact same point on the rear end of a condenser lens? If not fixed to the inner concave of of a spherical shape, then how about in any formation with wide fiber optic cable aiming the individual lights at their destination (the input-end of the condenser). Perhaps have all the points of the led's hit the same part of a condensor that is aimed at the Norpro reflector?

[jtbullet]

This is the kind of troubleshooting we need in pre-construction.
The first thing I need to know is what LED to try. There are a lot of choices.
I am hoping that you stumbled onto something:
If we had a perfectly (half)spherical reflector, could I not mark off equidistant points on the reflector , drill it and position the leds on the inside surface? Would colimators improve or degrade the image?

[Mikey p]

If the design goal is to make a projector using a 7 inch Lilliput, then specific information is already known. There are plenty of 7 inch projectors that have been made with excellent results. Most have used a 250 watt bulb producing an intial 25,000 lumens. Do you think a reflector with LEDs mounted in it would be able to put out this amount of light? If so, how many Leds would it take? The amont of LEDs and thier size would dictate the size of the reflector. I am curious as to how big it actually would be. This sounds like a very interesting project.

Mike

[dwalls32]

More importantly, does a 100 lumen LED light transmit exactly the same light as a 100 lumen halogen or MH?

If someone with a condenser lens and a few led's wanted to set up a test it would be cool. Otherwise I might order some and see.

[jtbullet]

Ace tells me I am going about it wrong. He says i need to make a light guide, which i translate as a tube, that changed the emitted light shape from round to square, then these squares make up a bigger square. Think flashlight with a piece of paper over the end with a square hole cut out. round light = square emission.

Yeah this project sounds interesting, that is why I am posting here, I am hoping to get the knowledge to give this project a go.

[dwalls32]

Doesn't that, in effect, just make a grid of equal proportion to the back of the lcd? 1 light per segment of screen?

[jtbullet]

From what he tells me it basically turns into a large flat led.
How that will work who knows. I was hoping we would see flateric's results but it'll be a bit longer i suppose.

[HiLLBiLLY]

I shall be watching with interest but can't see how you are going to get anywhere near the lumen output of a 250watt MH without using literally hundreds of LED's

For example

http://www.luxeonstar.com/item.php?i...rtno=LXHL-MWJA

Notice these Luxons (18 of them) mounted on a board only put out 450 Lumens @ a cost of $US268 i might ad

Guarenteed i'll be straight into LED's once you clever fellas work away out to make them work (if they are cost effective) and on a par with a metal halide, but un-fortuneatley at the price of LED's at the present time I simply can't afford to buy them to "experiment" with. At that price seems also out of range of the average DIY'er don't it? aint DIY meant to be budget? I realise in the long run many many many years they will pay for themselves but for the initial outlay it would be cheaper to go straight out and buy a commercial projector.

Just my 10 cents worth (bout all i got left too after building my projector lol)

Anyways good luck with it guys i shall be watching eagerly at this thread.