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Coral Vue Hydros

Come in and join me....


evilc66

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Come and follow along with my efforts in trying to find out if DIY LED lighting is worth all the hassle, and if PFO is just way too overpriced for what they offer (I'm pretty sure they are, but it will be fun to find out). This thread will be updated as I make progress on this, so please be somewhat patient.

 

First off, the premise as to why I am doing this: I have always been facimated with LEDs since I was a kid. I have followed around all the new technologies and have seen the battle for who has the brightest of the bright out there. Now that the cost of these LEDs has now become somewhat more practical, they are now more appealing to the casual DIYer like myself. After getting into reefing not too long ago, and reading up on all the different lighting options out there it became apparent that LEDs could be a viable alternative, but only if you could get it down to a respectable price point.

 

Now, the area where I saw the most potential for something like this was in pico reefs. Tanks of this size are so delicate because of evaporation, and 90% of it is caused by the heat from the lights, or the airflow from the lights cooling system. I am now starting my own pico reef, and thought this would be an excelent opportunity to try this out.

 

Working in the electronics field, I came across the new Lumileds Rebel LED. These things are pretty sweet. Super tiny emmiters, but with outputs up to 130 lumens. For those who don't know, that is more light output than a 35 watt halogen bulb (typical car fog light). :o

 

more_leds.jpg

 

Above are the LEDs I will be using for this project. I have a total of 20 LED at the moment. 10 white @ 130lm 6500K, 10 470nm blue @ 28lm. This picture doesn't really give you any appreciation on how small these are, but you will see soon. Now, a lot of you familliar with this kind of stuff will point out that there are companies that sell these LEDs already mounted onto a PCB to make life easier in assembly. Well my answer to that is that they want WAY too much money for them. Average going price for a single 130lm white LED mounted is about $15. I paid a total of less than $6 for the parts seperately. I have the experince to build these kind of boards, so making it myself was not of great concern. I don't recomend doing this if you do not have any experience in soldering surface mount components. It is very easy to destroy these parts if you are not careful.

 

pcb.jpg

 

These are the PCBs I ordered for these LEDs. They are set up to take up to three LEDs in series, so I can get real creative with color combinations.

 

pcb_and_led.jpg

 

Here is a closer look at the PCB. These things are really small (15mm accross). What is interesting about these is that they are made of aluminum instead of the typical fiberglass. This is so that the PCB can be used to pull the heat away from the LED, and transfer it to a heatsink behind it. This will be very important. While the LEDs do produce heat, it will not be close to what a CF or MH bulb wil generate. Look closely an you will see one of the LEDs next to the PCB. Now you can really see how small these things are. :lol:

 

Next up is how they will be powered....

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I know that some of you that have been doing research into LEDs know that you can't just dump voltage down it's neck and expect it to live for very long. LEDs are current driven, not voltage driven. With the current regulated properly, LEDs will last for years. Most of you that have experimented with LEDs have probably notice that they tend to fail quite regularly, and it is probably because the current has not been controlled properly. The absolute simplest way to hook up an LED is to use a current limiting resistor. While this works, it has it's pitfalls. One big problem is that it can't control an issue called thermal runaway.

 

Basically, when an LED is on it creates heat, and draws a certain amperage. If the current limiting resistor is sized so that the led produces maximum brightness, or maybe more it can get into a nasty cycle. The LED will heat up and draw more current. It will now make more heat because of the increased current, and draw more current as a result. I think you can see where this is going. After a while the LED burns out. While this is not such a big deal with inexpensive 5mm LEDs, this can put quite a hurt on the walletwhen dealing with these high power LEDs. Not to mention the utter frustration of having to fix it all the time.

 

So how do you fix this you may ask? Two ways. First is the commercial solution. There are regulated current sources available for this specific application. It's a great way do get the job done, and there aren't terribly expensive. This is the only way to go in my mind if you are not electronically inclined and want to play with high power LEDs. Second is the DIY solution (would you expect anything less ;) ). Using only two parts, costing only a few dollars you can do basically the same as the commercial solution (with some differences of course).

 

current_source.jpg

 

The circuit above is a basic representation of how it works. I'll get more into the details of how it works once I start showing how the circuit is built. The basics are that the resistor (R1) is used to regulate the current to a specified value. This will allow us to stop thermal runaway, and not have to worry about input voltage fluctuations screwing with the LED.

 

voltage_regulator.jpg

 

This is the voltage regulator I'm going to use. It is commonly know as an LM317T adjustable voltage regulator. It is capable of regulating from 3.25V-32V @1.5 Amps. Not bad, and you can find them cheap. There are a lot of different variations of this LM317 regulator, so you have to be careful if you are getting one, that can handle the current you need (some only do less than 0.5Amps).

 

resistors.jpg

 

These are two different value resistors that I will use in the circuit. These values (3.6 ohms and 1.8 ohms) will be able to let me limit the current to either 350mA or 700mA. 700mA will create higher light output, but will also generate more heat. We will have to see which will work the best.

 

power_supply.jpg

 

None of this matters without a good power supply. While the little wall wart style transformers are appealing because of their cost, they suck at keeping voltages constant. I'm sure some of you have heard me complaining about them in other parts of the forum :P . A switching power supply like this is a little bit more expensive, but not by mutch. This unit is 12V @ 12.5A (10 times more than most wall warts) output. Would you beleive me if I told you that it was only $42? It will supply more than enough power of all the LEDs, multple fans, and then some, and it will be perfectly regulated. Not to shabby.

 

 

That does it for today on the pieces and parts end of things. I'm still trying to find an appropriate heatsink to fit the dimesions I want. Anyone know where I can get large heatsinks for cheap (not PC ones, 150mmx150mm)?

 

Tomorrow I start assembling one PCB to test things out. I'll let you know how it goes ;)

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thats a pretty nice power supply...

 

it would be a lot easier to just use a constant current driver that is made just for high power LEDs.

i got one thats set at 700mA and its switches from 24-48v. (bought the last one =p and it cost me $29 shipped)

(i can power up to 12 LEDs at 3w) more then enough for a small pico.

 

I hope u bought the LEDs at Future Electronics cuz its the cheapest place u can buy them at.

 

http://www.future-mag.com/0707/070730.asp

sometimes they have them sometimes they dont...

 

u should have talked to me first about which is the best LED for the buck...

i got these instead.

http://www.kaidomain.com/WEBUI/ProductDeta...spx?TranID=2308 (best iv seen so far)

 

im guessing u got the 130lm LEDs cuz they ran out of the better ones?

 

if i want to increase my lighting im going to buy these next

http://www.kaidomain.com/WEBUI/ProductDeta...spx?TranID=2956

240lm at 3 watts? wow

 

i got a great deal on them but i paying for it cuz the shipping is taking forever (its free shipping)

 

u should have gotten royal-blue LEDs since they have more of a effect on coral. (solaris uses royal blue)

 

for the blue LEDs im using K2s from my old project...but im testing these

 

http://www.kaidomain.com/WEBUI/ProductDeta...spx?TranID=3311

its Cree (great LED company) i heard they give out 30-40lm per watt. but im going to see if thats true...

if their brighter then the best Rebel (i have one left...) then im ordering more!!

 

10 LEDs 5 white 5 blue will cost me no more then $50 in the future. (good LEDs)

thanks to thos people at CPF of all the info. and shopping list.

 

sorry for the high jack. i would have made a thread on DIY high power LEDs but my supplies are still being shipped to me. u just beat me to it...

 

how much lumenation do u think your going to get out of your array?

and whats the tank size?

 

will start mine soon too but first i got to make my tank.

 

i wish u the best!!!

 

 

btw since your blue is better then your white (BIN wise)

its going to look really really blue. i did 50/50 too before.

hope u like a high kelvin look.

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btw if u want a big heat sink

http://cgi.ebay.com/HEATSINK-ALUMINUM-EXTR...1QQcmdZViewItem

try to talk to him about custom size and i bet he'll give u a deal.

 

but for me i just went to homedepot and got myself a aluminum bar (36" X 2" X 1/8") pretty nice.

im also going to but a bunch of small heat sinks on top with a fan (the fan makes all the differences.)

 

u should think about ordering from kaidomain.com and dealextreme.com

free shipping and the cheapest prices out there.

 

oh and i also got a multicolor LED (blue red green) so it can bring out all the corals colors.

 

just a question were did u get thos star boards? and r there ones design for like 3 rebels?

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Thanks for the link to the heatsink. I'll have to talk to him to see if I can get what I need.

 

As far as the LEDs, I know there are more powerful ones out there, but there was a specific reason to get these. These are by far the smallest high power LEDs out there right now. The don't have the highest lument per watt output, but when you can fit 3 on a single PCB and get 390lm output from an area less than 15mm across, that sounds good to me. Plus, I can mix up the colors on a single board. I can now put two white and one blue on a PCB and get an actinic effect with little to no color seperation. There are other reasons I chose these LED's, but I'm not going to get into every specific reason. I chose these because this is what I wanted, not because it's the most powerful, which it's not.

 

Sorry to say it, but if you read the first post a little more closely, some of the questions you asked were answered.

 

Yes, the PCBs I have can take three rebels at once. The company I bought these from offered multiple different types of boards for different configurations.

 

From what I have read so far, Royal Blue is not as good a choice as just regular blue. The Royal Blue pushes the color spectrum higher. 470nm blue has been well documented as being one of the best wavelengths for growth in almost anything.

 

BTW, 130lm is the brightest unit they sell to the public through distributors. The brighter ones you can get quoted from Lumileds, but I'm sure they want you to buy 5000 pieces for them to even consider it. And yes, I did buy from Future.

 

 

 

Please keep in mind that this is an experiment. I will be making mistakes along the way, and correcting them as I go. Comments, advise and CONSTRUCTIVE critisism is always welcome, but please read everything I have posted before firing off questions that have been answered, or commenting on things that I haven't done yet.

 

This thead is here to also help anyone else that has an interest in dealing with high power LEDs.

 

Sorry for seeming so defensive on the topic, but I don't like getting posts that start out "Why did you get those ones. These are way better than the ones you are using." I have my reasons for everything that I have picked out so far. Please respect that. Ask me a question like "Why did you pick those? I'd like to know your reasons for it." That is something I will respond to better.

 

Sorry for the rant.

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sorry to be offensive =p

 

iv did the exact thing that u did. hope yours goes smoother...the resistors and regulators go really really hot...make sure u have a good heat sink with a fan...(the fan is not optional!)

 

if u call future to buy the best rebels uour going to have to buy 250 min. but it comes down to like $4 a LED which is pretty good. =p

 

well JUST if u dont want to use resistors or regulators try using these.

http://www.kaidomain.com/WEBUI/ProductDeta...spx?TranID=2982

 

(if my uncle wants to convert his 55g to a SW i 'll be getting about 25 of these XD

along with 40 of these http://www.kaidomain.com/WEBUI/ProductDeta...spx?TranID=2956

and 35 Blues somewhere...

im guessing around $400 from scratch to 225w LED set up.)

 

i'll post pics of my heatsink and fan just to get u an idea of what im doing.

I really want to use a aluminum bar with these http://www.dealextreme.com/details.dx/sku.8942

i would have ordered them but its too late now...dont want to w8 another 2 weeks...

 

your not going to use lenses or light defusers right?

 

just a tip from my past mistakes. double check your wiring if u mess up u can lose 1 LED per series...and weaken the rest.

 

u can wire the 700mA in series to but that in half so u dont have to get bigger resisters.

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Sorry for sounding b1tchy before. The biggest reason for the regulators and resistors getting hot is having them dessipate too much power, and also sizing them correctly. I'll get into more detail once I start building the regulators.

 

Thats a pretty nice little switching regulator. I'll look into that if there are problems.

 

I haven't decided yet on the use of lenses or diffusors. Again, this is a learn as I go type thing. I may find that I get great results without any lenses. Who knows.

 

This circuit will shut down before it destroys all the LEDs if one goes out. If one dies, the regulator now has to try too hard to keep things in check, will overheat and go into a thermal shutdown mode. No damage done at that point.

 

There is more to come. Don't worry, I'll explain everything I have done when I get to it.

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yeah that is a pretty nice switching regulator. i was planning to use it to make a 3x LED flashlight (thats over 500lm!!!)

 

whats the size of the tank that your using this light on?

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Tank is 8x8x6". I have another thread started for that that I will be updating in parallel with this one. Hopefully I can get some work done on both today. This weekend was busy!

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your going to have like 20 LEDs on a 1.6g tank? dam XD

u plan to grow SPS? lol

 

im trying to get 1-2 LED per gallon or place them close together and have coral right under them.

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I'm not neccessarily using all 20 LEDs. Thats just how many I ordered for this experiment. But I would like to be able to adapt this setup to keep whatever I or someone else would want.

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thats a great idea.

 

too bad i max out at 35w...

 

i guess i'll be using thos regulators. at $3 thats a steal!

 

im going to see if i can get a 15v power supply somewhere.

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Got the first regulator soldered up and the first led group lit up.....

 

 

HOLY CRAP THATS BRIGHT!! :o

 

I strongly recomend not looking directly into these. I've had spots for the last 20 minutes. I'm currently running two whites in series @ 350mA (200lm). This is going to get interesting.

 

I'll have pics up later tonight.

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Here comes the first test.

 

leds_wired.jpg CIMG1131.JPG complete.jpg

 

So here we have the power supply all set up, LEDs hooked up and the current regulator all done.

 

Now I did say that I would explain the regulator circuit a little more. The regulator is the LM317T that I mentioned earlier. Theses are readily available from many places including Digikey, Mouser, and Radioshack. Now looking back to the little circuit diagram I posted in the first post, the resistor is placed between the adjust pin, and the output pin. Not to get into too much into intricate details, but the regulator is forced into a current limiting mode. On the output pin, there is always at least 1.25V. This is how we are going to regulate the current. With the resistor where it is, the current can be kept steady because the voltage is constant. Using ohms law, dividing the voltage from the output (1.25V) by the current you want to supply the LEDs, which in this case will be 350mA for now. 1.25/.35=3.57 ohms. Digikey has pretty much every resistor value you could ever want.

 

Now, because the voltage is constant, and with the appropriate resistor, the current output is now always going to be set where you want it, regardless of what you're source voltage is. Simple but effective.

 

We are not done yet. You now have to size the resistor to handle the load. It's easy. All you do is multiply the 1.25V regulator voltage by the current you want to drive the led by. So, 1.25*0.35=0.43 watts. Now they don't make a 0.43 watt resistor, but they do make a 1/2 watt one. You can go bigger too, but they get physically bigger the higher the wattage. If you undersize it, it will overheat and burn out.

 

The source voltage is the last thing to deal with. You have to do a little adding to get this one straight. First figure out how many LEDs you want to put in series (I'm doing 2). So for me, I have 2 LEDs @ 3.4V each. The voltage regulator needs 3V to operate properly, so add that in too. You will want to minimize the reserve voltage so the regulator doesn't have to work as hard. So we have 3.4+3.4+3=9.8V. While you could go out and find a 10V power supply, a 12V one is more common. Anything higher than that for two LEDs will just be wasted in heat, and will shorten the life of the regulator.

 

Everyone get that? :huh:

 

So now its done, on to the results.

 

led_off.jpg led_on.jpg

 

Keep in mind that this is only two white LEDs that are not being driven at full current. I'm outputting about 200lm total right now, and no blue. Thats pretty impressive.

 

Well, thats the first test out of the way. More to come. What do you think?

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how did u mount the LEDs on that?

 

i love how compact and cheap thos LEDs are but thats the downside too...

 

anyways im still w8ing for my LEDs to arrive...cant do anything right now since the heatsink glue is with the shipment...

 

hopefully it comes 2morrow...if not this week im screwed...

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More to come. What do you think?

looks cool! i'm wondering when you're going into mass production and setting up a website for orders? ;)

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:D I still need to get mine finished, never mind building for others. But I'm not rulling it out either. ;)

 

@Coolwaters: What are you refering to as a downside. Your description wasn't too clear.

 

As far as mounting them, they are surface mount. You can't use a soldering iron to solder these up because the point where you solder too is under the LED. You can use hot air rework tools (like I have at work) or a reflow/waveflow oven that is designed to do surface mount stuff.

 

I love how tiny these things are. A Cree, Seoul or K2 LEDof the same output is more than twice the size.

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not all of use have the benefits and luxury of having hot air rework tools...

 

i had to use heatsink adhesive to mount them on the edge of a heatsink and then solder the inputs...

it was soo much work but i manage to get 2 in.

 

thats the last time im working with rebels...thats the downside i was talking about. so much work wire such small things. i mean its unrealistically small.

 

the best rebel is around 100lm per watt which is great and the best cree (Q5 ) is 114. which is almost the same...if heating wasnt a problem then u would see solaris hoods less then 1/2" thick. now that is what i call low profile. XD

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The biggest advantage I see with the rebels is that even though they do not have the highest light output, I can fit three 130lm LEDs on a PCB that is 15mm across and produce 390lm in the same space as ONE Cree, Seoul, or any other high power LED, with more output.

 

Granted, they are a little hard to work with, but for me the above advantage far outweighs how difficult they are to work with.

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I got 6 LEDs set up right now (4 white, 2 blue), and I think the light output is around the same as a 35W MH. The color looks great and the shimmer effect looks awesome. So far it doesn't look lie I'll need lenses for this. I'll try and take a picture later this afternoon.

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6 leds with the same power as a 35w metal halide?

lol over exaggerating. metal halide has a lumens output of more then 70lm per watt. so thats about 2500lm

no way 6 LEDs will give u that.

 

cant w8 to see it

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Ok, maybe a little :P . It really does look close though. It's already a fair bit brighter than the 42W PC I have over my BC14.

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snowlancer2720

hey evic66 - could you tell me the website that you go tthe PCB on, I think I may try to work with these LED's as well. Also, is there any other way of attaching them to the board without using the hot air rework tools? (Since i dont have access to them) Thanks!

 

-Joe

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I got the boards from a guy in Germany @ www.led-tech.de . They have a few different sizes and configurations on the site. Don't expect them to show up quickly! It took mine about a week and a half for mine to show up, but the boards are really nice.

 

As far as working with the rebels, you have to be really careful. One tool that is easy to work with and can do surface mount stuff for spot job is a butane soldering iron. Most of these have different tip options including a hot air nozzle. The trick is not applying the heat directly to the part. You will burn it otherwise. The easiest way to do this is as follows:

 

1) Tin the pads on the board (if you don't know what tinning is, don't continue any farther). You will want to completely cover the pads with solder, but with as little solder as possible. It is easier with fine solder and a good fine tip iron. Liquid flux will help too.

 

2) Apply a little liquid flux to the surface of the board. Get it damp not soaked. If you soak it, the flux will boil when you heat it and the bubbles will pop the led off the board. This will help the solder wick onto the pads of the LED.

 

3) Place the LEDs on the board and get them set up close to where they should go. The solder will do the rest of the work moving the parts.

 

4) Start applying heat AROUND the LEDs with the hot air nozzle on the iron. It is advisable to place the PCB on something that wont burn. It will take a minute or two for the board to heat up enough to start melting the solder. Once the solder is melting, you will notice the LEDs jind of shift into place. If they are too far off, just nudge them into place with a small screw driver.

 

 

This takes practice to get good at it, so don't expect to get it right the first time. You might want to have some spare LEDs handy. Just remember to take things slow. The slower you go, the less chance of scorching the LED.

 

There are other ways to work with smd parts, including modifying a toaster oven, and using a skillet on low heat. I've never used the skillet method.

 

 

I hope you find this useful, but be careful.

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