Introduction: LED Projector Lamp V.2.0

For those of you who stumble upon this instructable, a bit of history is mandatory in order to better understand my goals with this LED projector lamp. Therefore I recommend you first read the LED Projector Lamp v.1.0 instructable I posted a while ago. Check back when you’re done for this second part of my adventure.

For this version of the projector lamp I knew I had to find a way to at least double the amount of light on the projection screen. As high-power LED’s are very expensive parts around here (I live in Sibiu, Romania) I wanted to try making my own LED array. I chose the NS6W183T LEDs from Nichia. For those of you who don’t know, Nichia is a Japanese company that produces high quality LEDs and were the first to invent the high power blue and white LEDs back in the 90’s. These LEDs were available around here and the light output was tempting.

This instructable is not yet finished. Also the timeframe on this project is unspecified. I'm publishing its progress because I need other user's opinion on some matters in order to finish it. If you think you have something truly valuable to add to this project, be my guest and share you opinion in comments. I'll try to answer them all.

Step 1: Bill of Materials

My choice for the NS6W183T LEDs was based mainly on the light output & size. These are SMD components and for their size they put out an amazing 245 lumens each (when powered with If=700mA). I had to settle for an array of 9 LEDs, mainly because of the price involved. My hobby budget is very limited. Even so I paid about 55 Euro or 66 USD on these LEDs. Expensive for Romania, cheap for everyone else. The main goal is filling the entire projector condenser lens with light and the array does just that. There’s a problem though. The SMD LEDs I got have the light beam spread at 120 degrees. I had no choice but to go with that, in hoping that I’ll find a way to focus this light somehow.

The cooler selected (see the Cooling step) was 87 RON, that’s 24.5 Euro or 25.5 USD. I got this one because no matter the outcome of this lamp project I’ll still have a future use for it. The rest are scavenged parts, not really worth mentioning. People in the DIY community knows the importance of dumpster dives.

Final cost of materials so far is around 100 Euro, give or take. One more failed project and I’ll get to hear my wife saying “you know, you could have bought that original lamp already, given the already spent amounts”. Now that’s what I call painful irony.

Step 2: Making the LED Array

The array was made as compact as possible so as to avoid having a too dispersed light generating area. That’s because all the projectors light originates in a single point. With arrays you get several and the challenge is to focus them all in one spot. I will deal with this later, for now it’s a long way until then.

The 9 NS6W183T LEDs are arranged in series, on a custom made PCB board that’s 3x3cm. The LEDs are soldered in the center of this board, inside a 2x2cm square. I could have made it smaller but I can’t solder SMD components using reflow soldering, all had to be done by hand using a soldering iron. Each Led was checked for polarity, glued on the board using Arctic Silver Thermal Compound glue and soldered quickly and carefully. You don’t want to cook the LEDs too much, they are so fragile when it comes to temperatures. My goal is to transfer the LED-generated heat to the PCB and then further to the cooler behind the plate. Four screws will hold the PCB onto the cooler thus avoiding PCB warpage and thermal paste will be used in between the PCB and the cooler.

After all the LEDs were soldered on the board, a quick power check ( a few seconds) proved the array was operating properly and the light output was huge. If you make the mistake of looking into the LEDs (like I did) I guarantee you’ll see nine dots of light for a long time. Hopefully I’ll make good use of this very uniform light.

Step 3: Numbers

9 LEDs like the one I’m using will require 700mA at 31.5V for a total amount of 22.05 Watts of consumed power. Under these parameters I should be getting at least 2025 lumens. Provided I can keep the LEDs temperature under 70 degree (Celsius) I could then try and power them at 800mA and then I’ll be getting 2340 lumens. I assume the light losses inside the projector will cut this output in half. My goal is to use this projector in its original eco-mode, when the lamp output was only 1000 lumens. Hopefully, I’ll now get closer to that than the last time I tried. I’ll be using the same power supply I was using for the lamp v.1.0, it’s a 700mA constant current power supply. It outputs up to about 30V so I will be close to its maximum rated power output. Checking with a multimeter, the current was indeed steady at 700mA but the voltage was only 29.2V. Good enough for initial tests.

Step 4: Cooling

Another concern is the dissipated power, each LED is rated at 3.2W of dissipated power. That sums up to 28.8 Watts of heat I need to get rid of. Given the confined space inside the projector (5x5x9cm) I had to find a cooler that would fit inside this space. A very extensive Google image search made clear that the best option for me was the Nexus NHP-2200 chipset cooler. This one is using heatpipe technology to cool down computer chipsets. It’s made entirely out of copper and it fits the space available while the cooling fins are exactly where I wanted them, in front of the projector’s cooling fan. This cooler is truly a beautiful one, I tried handling it with gloves to avoid fingerprints all over it. The cooler base came a bit oxidized already but that won’t affect its performance, just the overall looks. The tricky part will be to make it cool the LEDs as the PCB I’m using should have been made of metal but I don’t have such technology at my disposal. I’m counting on the projector fans, there are two in front and a big one for the backside of the bulb. Hopefully these will help keeping the temperatures under control.

Initial tests proved the LED array is getting hot really fast, without cooling the array the PCB is too hot to touch in under a minute. The temperature probe on my multimeter reached 70 degrees (Celsius) in a few seconds but this was without the projector fan’s cooling. I have no way of checking the array with the projector’s cooling just yet so I’ll just go ahead with it. Hopefully I won’t fry the LEDs too soon. The Nexus cooler works, it also got warm in a minute but the heat transfer between the array PCB and the cooler’s base was slower than expected. By the time this cooler warms up, the LED array is too hot already. Man I wish I had one of those metal PCBs…  The three projector fans should help, at least that’s what I’m hoping.

Step 5: Casing

Believe it or not, to me this was the hardest and most labour-intensive part. As the entire LED conversion should be non-destructive and I had no original bulb at all, I had to replicate as best as I could the original frame and mounting points. There are two mounting screws inside the projector and a few plastic pins to be considered. None of them was in line with the others. Therefore I had to measure all I could measure inside that little space inside the projector and try to make a mock-up of my lamp casing out of cardboard at first, to check the measurements. A few cardboard models later I had all the correct distances. The PCB board I used for this casing is a great material to work with as it’s strong, can be soldered in 90 degrees angle easily and will hold firmly in place all I can put inside that frame. The hardest part was to cut the PCB board into the various shapes needed to assemble the casing. I used a tiny jigsaw and all I can say about that is that it was one painful experience.

Step 6: Light Control

As this array is square in shape I have no way of using a round reflector like the one I used on my v.1.0 lamp. So I’ll make a square one out of thin aluminum sheet. It will also control the light spills as that would disturb the projection experience. A second benefit of this aluminum reflector is that it would also double as a heat sink because its base will touch the LEDs thus taking away some of the generated heat. So it’s more a matter of controlling the light spills than directing the light beam, because, as I mentioned before, the LEDs have a 120 degrees light beam, I have no real way of focusing that too much. Lens are useless here because I have 9 separate light sources spread on a 2x2 cm. Fresnel lens are also not available around here. I was thinking of using tiny CD-ROM lens (from the optical heads) for each LED but those tiny lens have a very short focal distance.

This is where this project got stuck. I made a few attempts to use this lamp in the projector. The light output was bad. I have lights spills all over the place. The light output is blinding but I have no way to control it. The projected image is even weaker thant the one I did with the LED projector lamp v1.0. I blame the beam angle. If I can somehow find a way to efficiently focus this square LED array I believe the end result would be a success. But so far nothing worked. Maybe this forum will help me find the answer and this is why I'm posting this unfinished project. (and to get rid of the ones asking about its status) Ok, I'm just joking.

UPDATE: This LED Light bulb version is cancelled. Due to time restraints and the lack of encouraging results, I'm postponing this project until I can come up with something better. When I do, Instructables will be the first place to read about it, so stay tuned. Meanwhile the v.2.0 version is my new bathroom light. :-) Perfect white and high brightness, it's like a operating room in there.

Comments

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DeepanjanB1 (author)2017-03-03

Hi Claud! You still stuck with that mate? .... if yes then lemme know as I do have few cents to suggest to get through with it ;) ...

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JohanS80 (author)2017-02-23

Not sure my comment stuck.. I'll post it again..

I read another instructable where a guy used a small fresnel lens to focus the led array.. Perhaps that could be used here as well?

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FadiR1 (author)2017-02-22

Hey, very interesting projects. I'm thinking of doing it myself and here are the things that I would do differently. Maybe it would get you unstuck:

First off, cooling: LEDs run much cooler than the incandescent bulbs that are usually used in these projectors. Your LEDs run on 22Watts of Power whereas a regular projector bulb can run on up to 200W. The fans of the projector are designed to dissipate 10 times more heat than your LEDs produce, so the whole heat sync assembly is overkill, just line up your LEDs with the air flow of the projector fans and that will keep them nice and cool.

Now onto focusing the light. I was trying to brainstorm how a 120o light can be focus. I drew you a diagram of my idea. Forgive my bad drawing, I'm not a good drawer and I'm getting used to the tablet and the new drawing software. The basic idea here is to have in a little light well or cone made of some reflective material that will redirect the wide angles of the light. You can figure out the angle of the cone mirrors by taking a taking a normal mirror and playing with the angles until you have the light focus you want.

I think this is a great project and even though you may spend something similar to the price of a new bulb, consider that your LEDs will last you 10 to 20 times longer than an incandescent bulb and spend 10 times less electricity. Epson charges 350$US for a new bulb and they rate the bulbs at 4000hrs but alot of people in the forums say that they only last 1000. Your LEDs are rated for 50,000 hours.

ledproj.jpeg
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notingkool (author)2016-10-01

That lamp looks amazing!! it's a great idea for those like me that can't find the original lamps in our countrys!!

Very Impressive

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doddel (author)2016-02-28

The multiple LED lightsources with a single reflector system do create light of course but most of the light will not make it through the projection system. This is due to the so called 'Etendue' of any optical system, the product of the area through which the light traverses or from where it originates and the spatial angle it occupies. A loss-less system can only exist if the source's etendue is equal to or smaller than that of the rest of the optical system. If the etendue of the source is much larger than that of the optical system, most of the light will not be guidable through the system. The projection system has been designed for a high pressure arc lamp that is characterized by an enormous luminance, a light flux emanating from nearly a point, i.e. a very small surface. These lamps have many negatives (short lived, UV, explosion, modest energetic efficiency) but are hard to beat when it comes to their optical geometry, all the light comes from one small point and facilitates an optical system to capture, guide, and image it. The Luminance of a high pressure Mercury arc lamp is in the order of 4 Giga Candela per m2. That of a LED about 8 Mega Candele per m2. A factor of 500 less!

So when it comes to converting electrical energy into light energy without many contraints where that light goes, the LED wins (lumens per Watt) but when it comes to creating light that is useful in a projection system the LED is far inferior.

Conclusion:

Most projection systems are designed such that they operate, even with a high pressure arc lamp, in an etendue situation that is already not lossless.

So the total light emitting surface of the LED should not be bigger than that of the arc in the arc lamp. Assuming for simplicity that the arc is a little sphere with radius 0.5 mm, its surface is 4 * pi * 0.5² = appr. 3 mm².

Unfortunately from such a small surface a LED can only produce a few lumens.

Had this not been the case of course all projectors would have been using LEDs to start with. Latest solid-state trend is the use of laser diodes. They achieve much higher luminances than LEDs can but are costly at the power levels needed.

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Svartalf (author)doddel2016-09-12

Heh... The grounds for the premise is solid, but your premise is wrong.

http://www.projectorreviews.com/projector-categori...

Most of those don't have Laser LEDs...

Your premise fails on a few fronts.

1) 20k Lumens == 20k Lux == 20k Candellas.
2) The emitter source for the high pressure mercury arc is NOT constrained to 20 degrees, but rather 360- which makes the Candellas without the proper lumiary assembly down to 3k Candellas.
3) A similar "proper" lumiary assembly can be made to constrain the LED Emission profile to about 20 degrees.
4) With "1", all things being equal, if you constrain the light to 20 degrees of emission profile with low losses, X lumens *DOES* equate to X candela.
5) once you get past the 100 lm/watt range, you're in the domains beyond even UHP mercury vapor for luminous intensity.


Now, had you said it was "easier" to accomplish the focusing because of UHP being a point source for the light and the LED's being "more spread out", I'd have bought the statement in spite of the handwavium you're putting out.

However, since you went where you went...I need chest waders for it.


LED's have a potential to be made as good or better with performance levels exceeding 200lm/watt now with the right luminaries. It may or may not be that you can retrofit a projector gracefully with such gear, but it's worth trying. The reason why they have as many "fails" as we seem to have (with a few recent successes, albeit ugly as hell) is that it's harder to get the focusing you need to keep the light going in the right directions for projecting. It's not that it's impossible (you're seeing 800+ lm projectors in that list...)- it's difficult.

I'm happy for the challenge.

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claudiopolis (author)Svartalf2016-09-13

Had I known that my instructable would get me CERN-level comments, I would have just posted pictures :-). Thank you for your insights. But we're all beating a dead horse. I gave up on this. I find Xenon bulbs a much better alternative. Not as good as the original, but it does make a projector usable.

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SpinnerDave (author)2016-08-11

You could use the internal lens array from an old slide projector, though it may be too large to fit in the space.

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marian.synter (author)2015-12-27

Un proiect interesant si bine structurat... totul este OK. Un sibian.

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bogdan.dumitru.9674 (author)2015-03-24

Xenon man. Just do it.

author

That wouldn't make a very interesting instructable. This is a really cool project to me, one might do it to save on lamps, for energy efficiency, just to see if you can, or if you can't get the correct Xenon lamp because it's obsolete, you live in a place where it's not available, or you live in a place where mercury lamps are banned. Or, what if you want to modify the behavior of the projector? Say I'm using one for 3D printing and I want to drop in a UV led, this would be a good starting point. If you don't think making stuff yourself is stupid because you could buy it, why be on instructables?

author

It is the same story just using the correct lamp instead of LED which have a long way to go to put out the same amount of power. I'd go about with making a universal base with H1 socket mount and provide cooling for it. H1 xenons will be here for a long time and very cheap. I'd also think about using the original ballast from the projector if it's possible.
It is about the road not the destination but we also need to chose the right gun for the duck when hunting ducks.

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rcgigessss (author)2014-12-07

e fain, dar ai scris prea mult, ai intrat prea in detalii

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prdell (author)2014-11-30

http://cart.payments.ebay.com/sc/add?ssPageName=CART:ATC&item=iid:361105466378,qty:1

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prdell (author)2014-11-30

http://cart.payments.ebay.com/sc/add?ssPageName=CART:ATC&item=iid:361105466378,qty:1

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prdell (author)2014-11-30

What about using this one in the projector. No cooling. http://m.aliexpress.com/item-desc/2036097338.html

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kalamees (author)2014-11-14

Hey, isn't it possible to focus this led with this kind of led, reflector and lens?

http://www.ebay.com/itm/44mm-Lens-Reflector-Collim...

http://www.ebay.com/itm/Multi-Color-10W-30W-50W-10...

Anyone tried?

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jimvandamme (author)kalamees2014-11-26

I like what this ole boy rigged up. I might try it.

Another thing I thought of, is synchronizing the LED with the shutter, so that you get around twice as much light out and no flicker. Now, the light is mechanically chopped when the shutter advances. A sensor could shut off the LED while the film advances and you could remove the chopper. You wouldn't get any rolling shadow through your movie when you filmed it with a digital camera, would you? At least not if your shutter speed was slow enough.

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gerbr (author)2013-12-28

Have you seen the construction of the light path in a projector using red blue and green leds? You should try thr same with white leds!

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claudiopolis (author)gerbr2013-12-28

Sorry but I wouldn't tackle optics on that level. Using prisms and custom-made reflectors, sure, it will work. But I can't have those, nor do I want to lose the DIY spirit. Imagine how such a step will sound in a future instructable: "Step 4. Make a pentaprism using optical glass with one focusing lens having a focal point of 16mm". That might very well be the end of the instructable, none will follow you beyond that step.

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mikeyc.2009 (author)2013-10-15

Could you possibly use a light pipe system where you take the individual outputs into separate light pipes and combine them into one? This method might have the added advantage of mounting the LED's in a more dispersed pattern for better cooling efficiency.

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claudiopolis (author)mikeyc.20092013-10-15

Yes, it would. But I don't have the tools or the materials to come up with something like that. We're talking about advanced optics here. Stuff that the average Joe will never be able to replicate.

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mikeyc.2009 (author)claudiopolis2013-10-16

It might not take too much. If you have access to clear acylic rods and cement then you are half way there. You could use a standard torch or gas stove for that matter to heat the rods to shape. You just need to make sure that the joints are properly polished before you glue them. I've used toothpaste or flame to polish acrylic before depending on my needs. I'm thinking that there could be one center rod coming up from the center LED and the others feeding into the sides of that rod. If you have a steel rod the size of your center rod then you could mount it in a drill and use the toothpaste to lap the joint for a perfect joint. This method might not be the most efficient at light transmission but 75% is better than nothing.

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gazza154 (author)2013-10-15

With ref to Jpayton,in car ECUs they transfer similar heat by using thru hole plating under the component ,about 10 holes to copper on the other side.Has been working in the car industry for 10 years and I have used the same idea a few times.If anyone is still interested i will post some pics.

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claudiopolis (author)gazza1542013-10-15

I already solved the PCB heat transfer by using a aluminium PCB. So no thru hole system necessary. It would have been impossible, anyway, due to the SMD size of the LEDs and the fact that the LED's backside feature electrical connections so a short-circuit would have been unavoidable. The new aluminium PCB solves the heat transfer but the light output is the same, and that's the real problem.

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invisiblelight386 (author)2012-09-10

I am currently looking into a new LED. i have tried many ways to focus the light and it is just not worth the time and headache. I recently found this LED

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221037245498

Still not sure if im going to buy it yet. i am currently at college with out my projector and i want to do some tests and measurements before i buy it. maybe by quadrupling the lumens it will actually work.

do you think its possible to have too bright of a light source?

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jpayton (author)2012-02-13

What about drilling holes behind each LED then add some sort of copper plug that will contact the back of the led and push agenst the heat sink. and just load it with thermal paste. that should pull the heat stright from the leds. maybe even a full slit across 3 horizontal leds. that will allow some air around them. still use the copper plugs to contact the back of each LED.

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ensastiga (author)2012-01-09

I'm working on retrofitting my Epson Powerlite S3 with an HP LED. so far I'm thinking of buying this http://www.kaidomain.com/product/details.S009871
but 200 bucks exceeds my budget, so in the meantime I'll go for this http://www.ebay.com/itm/FREE-SH-1x-100W-Cool-WHITE-LED-Lamp-5500-6000K-Bright-Light-High-Power-KD7-/300645874069?pt=LH_DefaultDomain_0&hash=item45ffe3f995#ht_2846wt_956

Due to the nature of the lamp case of my projector (it comes with a collimator lens) I'm expecting not to have big problems on the light source focal point issue.

My only problem will be to fit the right cooling device on the small space that is left on the lamp compartment.

I'll keep posting my progress

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robertcook (author)2012-01-02

I agree with epolinda that a single LED plus a reflector is probably the right way to go. For a projector, you need collimated light (where the rays are parallel). Each of your LEDs have wide dispersion and without a reflector (and a lens), a fraction of your light is projected toward your screen. Put another way, a single, dimmer LED will actually project more light in the direction you need it.

Also, single high power LEDs are often packaged with a metal circuit board which will better transmit the heat to your heat sink on the back.

Another thing to consider with LED lighting is the spectrum that is output. It appears that you are using cool white LEDs, which output primarily in blue with a smooth curve between red and green. The problem is if you are filtering this into RGB digital output (is this the case?) then the LED spectrum may give odd or dim results (the spectrum notches may not line up well with the filters.) Worse, the color of LEDs change with heat and current and change over time. This is one reason why lighting with smoother spectra (halogen) is used for digital projection.

Also, I really like epolinda's suggestion about driving the LEDs only when the light is needed. That could help dramatically with heat dissipation and power consumption.

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jamwaffles (author)2012-01-02

It's such a shame to see a very promising project fail :-( What you have up to now is very good, however! That heatsink is beautiful, I must agree, but did you put a little thermal paste between the PCB and base? It wouldn't help much due to having the PCB material in the heat path, but it'd do something.

I wish you the best of luck for this project. Hopefully you'll fix the issues and come up with a working design. Thank you very much for sharing what you have so far!

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invisiblelight386 (author)2011-12-29

I am attempting the same problem. Focusing a square LED. Right now I'm using a 1300mA, 2000 lumen LED chip set. There is plenty of light ( I also made the mistake of looking into it ). I'm not too worried about heat. From my calculations it puts out 23.4 watts. Way lower than the original bulb that the projector used. After some long tests of the unit I have fond that the air exiting the projector from the fan is actually cooler than when the original bulb was being used. Right now I'm just trying to get as much light focused as possible. The hardest part so far was finding the bulb checking circut. I'd like to thank you for both of these instructables. They have helped so much. Hope you can find the time and motivation to keep trying with your own projector.

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tvm777 (author)2011-12-08

Ciao Claudio!
I was searching for more components at ebay yesterday and i found this:
http://www.ebay.com/itm/1-High-Power-50-Watt-White-Led-Light-4000LM-3336-/110786280582?pt=LH_DefaultDomain_0&hash=item19cb607c86

This give you 4000 lumens in one single shot, and i saw some videos on youtube of this thing working, and i can say its just amazing.
I've the same problem as you my hobby budget is limited, much people use USD but in my country my coin its in devaluation.
Anyways, this led its incredible cheap, even shipping its free to ROMANIA :)

check it and write me back :)

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claudiopolis (author)tvm7772011-12-08

I know that one. There is a 100W version too. The local reseller told me he won't be importing those anymore because more than half of their sold units burned out in customer's hands, The leds are overdriven and prone to failure in short time. Also the cooling required was insane. And besides, it has the same problem I'm having here; square light source, even wider angle, no way to focus properly...

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epolinda (author)claudiopolis2011-12-17

There are two points I'd like to add to this discussion.

First, if you use one of those high power LEDs, you don't have to make it work at full power. Some of them provide more than 10.000 lumens at full power, but you could drive it with a lower current, getting less light and dissipating less power.

The second point that someone could try is that the LEDs don't have to stay on all the time. If we drive the LEDs using a MOSFET and a small synchronizing circuit, we could keep the LEDs off during the blanking periods, we could reduce the power dissipation to a very lower level.

These are some ideas i have about this issue that I can't not test right now, but I would if I had the time and the means.

Best o luck with your project(or).

Emerson, from Brazil

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tvm777 (author)claudiopolis2011-12-08

I saw lanterns made of this, and according to most videos doesnt heat that much(i mean enough to be cooled with a single fan), BUT now i think about, most of proyects are LANTERNS, that mean that doesnt need to be turned on so much time, as a projector does.
I dont know about the lifetime about this, but im sure its long enough, but dont know about the fail on products, well, if fails before its suggested you can always claim refund as its an ebay user protect program, i dont see any necessary buying to locals (most of they win some commission on each sell) since you can buy yourself on internet and without pay shipping and rates.
What's your solution for the square light source?
IMO your tiny light source wont give much LUMENS

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claudiopolis (author)tvm7772011-12-08

there are 9 leds. Each puts out 245 lumens. You do the math. I'm trying to focus a square but with no real solution yet. If you read the entire instructable you'll get that.

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jetzi1973 (author)2011-12-09

Hmmm i just wonder if you hawe a old flashlight that you can adjust the beam on. If you can try to mount the led in the housing at the right possision so you get the right angle on the beam then you get it to work i think.
The housing on the old flashlights can take quit amount of heat.

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carlos66ba (author)2011-12-08

This looks very professional and very nice. I have one element of concern: the PCB is not really a good heat conductor and you are placing it between the LEDs and the heat sink. This does not look very good. Here is one possible suggestion: put some "sil-pad" on the heat sink, then glue to it the LEDs, then try to do wired connections between LEDs. This should improve the heat transmission.

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Timofte Andrei (author)2011-12-08

you are awesome :) smooth. clean and smart! you are an artist :) good luck :)

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Bio: I am a graphic designer with many hobbies. I love electronics, computers, LEDs and all things tech.
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