Hi people,

This is Ejder Yurdakul from Belgium. I proudly introduce you here my plog;

Light source: 8.4" led array from carpow (delivered)

TFT: 7" 16:9 xga liliput TFT screen. This screen is used to be a part of my CARPC, since the backlight was broken, i've been looking for a way to recycle it, and finally found this DIY forum.

Lens:
Triplet 320mm(delivered)
Fresnel 330mm(delivered)
Triplet mount (this part allows you to move your triplet few mm's.)(delivered)

Electronic:
VGA socket(delivered)
RCA socket(delivered)
16pin FFC extension(shipped)
2x 80mm fan with cover and silencer(shipped)

Power:
15V AC/DCadapter for leds
32V-6 to 12V DC/DC Converter for tft and fans (from my CarPC)

These are photos of the led array:

Back side


Front side


Close-up

This is my CARPC:


This is my TFT screen;


Totally striped


I am going to use plexiglass for casing.

Hi Ejderm !

The LED array is awesome. Did you solder it yourself ? And what kind of LEDs did you use ?

Very nice LED array. Where did that come from?

Thanks!
I've tried to do but it was too difficult for me, i couldn't get that much led on such a pcb. Presicion is very important if you work with leds.
This array comes from carpow/China.

edit: i'll try to post some photos of my homemade array.

any updates?

Well, i got the most of the parts but didn't have time to assemble them. These are some new photos;


-very strong leds-


-this is the triplet holder, still looking for a way to fasten my triplet in this PVC pipe-


-not pretty good but, enough for first pj-


-some screws and corners i am going to use for the case-

Tomorrow, i'll start to put them together.

I'm eager to see your results.

A friend of mine has this: http://www.mitsubishi-presentations.com/pr...ctors/pk20.html

I saw it over the weekend and I must say, it kicks ass. I couldn't believe something so small could be so powerful. I'm actually contemplating getting one of those for myself, to use as a daily TV/portable gamer.

i can't wait to see the result of the LED setup....

nice job!!!!!!!!!!!!!

First problem: I cut the fresnel with my dremel. I left accidently some scratches on the backside, it was really painfull to cut. I am waiting for the lens repair cream, i found on ebay.

Second problem: The DC/DC converter doesn't seem to work well with the 15VDC 4A Toshiba laptop adapter. There are three pins, ground, + and ignition on my M2ATX psu. I guess i need a ATX trigger system. Now i am at the point of integrate my carpc in the projector, since there is no heat problem. I will use an external adaptor socket, so there is no need for psu cooling.

Greetz

New photos;


-this is the triplet, mounted and adjustable-


-lcd screen, backlight and ag layer are removed, tested-


-this is another close-up to OSD-


-this is the fuse f100, this was broken, i've connected it with a clip (thanks to carpow), i'll repair it soon-


-this is the backside of the led setup-

Some more photos;


-another view of the backside-


-AC adaptor socket-


-leds are running with two fans-

The LED arrays are cool, I will be getting them in soon for the states.

I think the power is 50w.

How large will your LED arrays be? The actual length by width, if you know those details already.

896 leds, 3mm, 20mA, 20-25000 mcd each. This is the biggest available size. We buy from the same chinesse guy. 205mm x 150mm is the actual size of PCB.

Great....that's just about good enough for my panel.

What was the cost of the LED array? If you don't mind me asking.

do the leds go right to the edge?
can I put four of the LED PCB's together to light up a 15.4" panel?

I am selling most if not all of my 720p setup and I would love to do an LED setup for my 1080p build.

it should absolutely work.

European DIYer's , PM me for those led arrays and details.

Hi they look really nice.I would love to have one like that.

I pm you later got to goto work now

about how much do the led boards cost?

120 euro each + shipping. You have to calculate the exact dimensions of the screen and compare with the led array(200mmx150mm). If you use two arrays, the size would be 300mm x 200mm, be sure array is large enough for the screen.

I got my ledboard today [thnx to Redbullah]

It looks really nice,its definitely not hand soldered.I have tested it with almost dead 12V battery
cuz i don't have a 15V power sup at this time.I'm sure it will be much better when i have 15
it blinded me for a few minutes when i looked right into it.I post sum pic's of it later.

Next job is to gather the rest of my components,besides the leds have nothing
I'm kinda new to this PJ thing tho it catch'd my eye a few months ago. i already purchased a OHP 3 months ago
but the idea of such a big pj scared me. As soon as i start i make a plog of it

then i could maybe use 3 to cover the area that i want on a 15.4 inch screen
i won't be useing the full height of the panel. the active viewing area is 331.2mm X 207mm
I will be chopping off 120 pixels to get the 1920x1080 resolution i am looking for.

so the area of the panel that i am trying to light would be 331.2mm x 186.3mm
with 3 led boards together I would get 450mm X 200mm, it seems to me that would work perfectly because the LEDs go all the way to the edge of the long sides of the board so they would line up nicely.

what do you guys think about that?

redbullah would you ship to the US?

What about the Front fresnel placement, could it go behind the LCD like it does in an unsplit setup?

Great Plog. Thanks for putting this on the LL forums. It'll be a great resource for work we are doing with the high power leds.

are there any new updates screen shots maybe?

Do you know what the color temp is on these?
Tians setup was 7000K which is a little on the blue side
Tians LED board was also built using 30 degree LEDs which means a lot of wasted light in this type of application. Do you know what the angle of the light cones of these boards are?

I don't know the exact color temperature, they didn't look blueish to me. They have 30° light angle which allows you to use 80% of the total light and you can place the lcd closer to the light source since there is not so much heat. I am waiting for my new 8.4 screen, as soon as i got it, i'll post some screenies with real white balance, so you can deicide by yourself. I don't want to reccomend something before i try.

I wouldn't merge multiple led panels for a bigger screen. It would be a big waste of light. PCB is 50mm bigger each side, it may cause an uneven illumination too.

Before I asked this
do the leds go right to the edge?
can I put four of the LED PCB's together to light up a 15.4" panel?

and you said


now you are saying this


however it looks like the LEDs go right to the edge of the long (200mm) side, in that case it should work fine.

I also want to get a clear answer on this

did you mean that the PCB is 5mm longer than the PCB on the 150mm ends? 50mm doesn't make sense


these are the dimensions i want to cover
Click to view attachment

it seems to me if I put 3 LED boards together with the 200mm sides toucing it would give me an active lighting area of 450mm X 190mm which would cover the 331mm X 186.5mm area I am trying to cover.
Do the LEDs go right to the edge of the PCB on the long side as it looks like they do?

"it should absolutely work. "

When i said this, it was a fast reply and i didn't calculate your screen dimension at that moment. After that, i mentioned, you have to calculate the exact dimensions of the screen since led panels have to be at least equal to lcd. My opinion doesn't change the values .

Panel is 200mm x 150mm and 150mm edges are 5mm (indeed) longer than the leds.

You don't have to use a fresnel between lcd and the light source.

phutton,

Thanks for your comment. We all can see, the leds will be the future of illumination and DIY pj's.

How can I order one of these LED arrays?

You are welcome. PSU's will be available soon here as well. I'm glad to see you are satisfied. Let me know, when you start your plog.

Just to confrim, the LEDs go all the way to the edge of the 200mm sides?

Exactly

Theoretically 30° LEDs with no beam shaping lenses used with a standard triplet will only transmit about 10% of the light to the screen.

DJ

Is it? You can collect 80% of the light on lcd, which i mean. Transmitted light on screen depences on your setup and even the quality of screen. In anycase 30° leds can project more light than 360° HID lamp, and my setup uses only 50W.

I want to mention my goal in this project. As you can see, i am using only one adaptor socket for power and use the entire space for the pj components. My goal is building a tiny, handy, projector, which uses the energy efficiently. My boxes dimensions are 24cmx18cmx50cm. 135 mm distance between leds and the lcd, 20mm between 220mm fresnel and lcd, 325mm between lcd and the 330mm triplet. I could use a smaller tripler but i really want to place my pj behind the seats.

Yes 80% of the light probably will illuminated the LCD but once it is converged by the fresnel only 10% will make it though, the other 90% will simply be blocked by the triplet housing and the front panel of your case. 10% is a very rough estimate only taking into account aperture sizes (triplet diameter) and ray angles (LED angles). Reducing the size of the triplet will only make things worse. If you were to use 6° LEDs or some form of lens on each LED then a much larger percentage of light will make it through the triplet.
LEDs do show some promise. Most of there light can be directed forward but if the angles are wrong then they won’t be any more efficient than a MH, more likely to be less efficient.

DJ

DJ,
I am thinking of building an LED PJ and I have no need for keystone correction, all the LED PJs i have seen have the fresnel between the triplet and the LCD (like in a split optics setup) I am thinking of puttin the frezzie behind the LCD like in an un-split setup.

from back to front it would go LED board, fl550 fresnel, LCD, Pro lens

Do you think that putting the fresnel between the LED board and the LCD would help shape the light better, and perhaps be more efficient?
Is there some reason besides keystone correction that everyone has put the fresnel between the Triplet and the LCD?

First fresnel collect the light and send them straight thru the pixels of LCD. If you use leds, it is not necessary since most of the light goes straight to LCD. Fresnel blocks some lummens, so one is better than 2.

I am thinking of placing the lcd, very close to leds and see how it looks.

@dj

what do you call right angle is between 25° and 40° right? That's why you fail, if you use high power luminox or smd leds. They have 90° range.

mabey its just me looking at those pics
but those things do not look even close to bright enough

did they tell you how many lumens that array is ?

i am very excited to see you results and good job so far ..

The only reason to change the fresnel’s position besides keystone correction or light evenness would be to better match the triplet’s focal length. The position of the LCD is not really important.






Edit:
And yes 90° is a right angle just not the right angle I’m talking about.


About 6° is ideal, anything greater than this angle will be wasted. 6° out of your proposed 90° beam angle is not very good efficiency.
A very common assumption is, that if the LCD is illuminated with light that is all that matters, it’s actually not the case at all. The fresnel needs to have incident rays of a particular angle for any hope of them passing though the triplet.
Just so you can understand the concept, remove the fresnel completely for this example. Now using your 90° LEDs behind the LCD and a triplet placed at it’s focused position in front, not a great deal of light from each of the 90° beams is going to pass though the triplet. When a fresnel is added the same problem will exist except that now the 90°beams will be refracted slightly. Replace the 90° LEDs with something smaller and a much larger percentage of the beams are going to pass through the triplet.





DJ

http://diy2005.aa.topzj.com/viewthread.php...%3D1&page=1
Guys,
check this tiny light source. I guess 4 of them can illuminate a 3.5" lcd with ease with a matching condensor lense. 216 lm output is not bad for one led module with 80 emitting chips. Images look promising. What do you think.

@DAZZZLA,

Thanks for information

@jeffek,

if you look them face to face, you feel the power Those are 40° leds but you don't see the real light if you look at from the sides. Thanks for your comment.

strange...they look like wide angle leds, so multipoint lighting, and then just one condenser lens...and seems to work! do you know where to buy them?

DJ, I have to say that I am a bit confused, I thought ppl were saying unsplit optics gives you better sharpness and possibly brighter image? Are you saying that is just a matter of opinion and not fact?
I never got split optics working in my last build so I don't know from personal experience if this is infact true.

In an LED build there is no such thing as split or unsplit however if the LCD is between the fresnel and triplet it seems that it would mimic the benifits of an unsplit setup. It seems to me that the LEDs would shine on the Front fresnel and the front fresnel would be able to push the light through the LCD at a better angle, especially with the longer FL fresnel and triplet the light would be going very close to straight throug the LCD panel.

I guess I will just have to try it and find out. The only downside is that I need to get 3 LED boards to do what I am trying to do, and that is a little pricey.

Besides the computercowboys countless questions about building a led projector, i am still waiting for my LCD kit from carpow to complete my pj. After that, we will see some screenies.

Hi, yes they are very bright and small, 215 lumen output is not bad. Cooling is an issue and they need 30-30V dc as well. I am still looking for a supplier in China. I'll visit China next week and look around for powerful leds.

And matching 6° lenses?

Sorry, wasn't trying to take over your PLOG, the LED stuff is still pretty ground breaking, I tend to beat things to death a little bit.

@computercowboy

No i didn't mean it that bad, maybe i should put a smiley at the end. Please go ahead, i am glad to see, you are interested in leds and want to give a try.

@DAZZZLA

i'll look around and see what is going on there. My first aim is those 50w leds, i am sure, 2 of them would be great with a condensor lens and Prime View 3.5" HD LCD. Can you imagine, how small your enclosure can be with such an install.