Ultimate LED guide

[ajgouty]

Thought I'd chip in with the project over here. I can't release all the details about how we're getting this kind of output or what chips we're using.. but.. I can post some teasers.

 

 

shows the test board size. a center row of blue LEDs will be added later.

 

 

shows how thin the board is and why we DON'T need heat sinks.

 

 

Shows how efficient the board is.. this is running off of a Makita battery... less than 750mA draw at 12VDC for the entire array.

 

 

In the test BioCUBE 29

 

 

Before the dust settled from putting in the LR.. but you get the idea...

 

So how does this prove heatsinks are not needed? You state the entire array runs at less than 750mA. Most individual leds run at more than this. Sometimes 3x more which produces a lot more heat.

 

 

I've seen some single LED heatsinks being sold here and there that have a huge hole in the center of the heatsink. RapidLED for example.

 

 

This seems very unintuitive. That big hole is exactly where the LED is on the star, and that's where the heat is.

 

Right?

 

 

 

 

Yes but it is taking the heat away from the center.

 

 

 

 

 

It would work fine for running DC-input drivers like Buckpucks. Not good at all for direct driving LEDs.

[Division50]

So how does this prove heatsinks are not needed? You state the entire array runs at less than 750mA. Most individual leds run at more than this. Sometimes 3x more which produces a lot more heat.

 

Well, the only way to "prove" that heatsinks are not needed is to turn it on and find out how much heat is produced. I'm NOT using DC power to run these.. I'm able to put out MORE lux on LESS current... it's not always about how much you shove into it, but what you get out of it.

 

The board pictured is made of aluminum and is all the heatsink needed.. it's bolted directly to the plastic on the BioCube and after 12 hours, the plastic is barely warm to the touch.

 

As far as brightness.. its PLENTY.. as far as spectrum, I'm not worried.. if I have to add another row of LEDs to add in Red and Blue... not a big deal... if 12 LEDs don't overheat, I'm pretty confident an additional 6 won't either.

[madfx]

nvm I guess

Edited December 11, 2011 by madfx

[Mojorizn]

Evil - Thanks for the post

 

I'm past page 95 of this thread (yes I read them all) and have to cheat a little with the "recommend my array" question.

 

65 Gallon with center brace 36x18x24 currently running 2x150 MH + 4x39 T5 in a custom canopy ...

My canopy is 6 inches in height and I wish to replace the current setup with an LED array within the canopy.

I have cooling fans and exhaust fans already in place with my current setup...just an fyi.

Increasing the canopy height or suspending an array a foot or so above the tank is not acceptable.

 

I'm thinking a 1:1 RB / NWorCW ratio with maybe 6 UV (at a later date) for kicks and punch.

Don't need moonlights, already have them.

 

I wish to avoid over-kill so I can actually run the LED's with some power, yet keep everything enclosed within the canopy putting the array around 4 inches above the waters surface protected by a glass or acrylic shield.

I currently have a good 9 inches from the MH surface to the top of my "tallest" sps colony.

 

I can play with a variety of optics as needed. I have a mixed reef with (generally) SPS up top and LPS / polyps lower in the tank. Also have a clam on the sand bed. I also have an RKL controller I need to research and see what , if anything, I can do with that.

 

Was thinking, 64 LED's (4x16) on a 8.5 x 35 ish heat sink with 2" spacing both ways. I have a center brace in the tank, so there would be a gap of ~3.5" in the center of the array.

Although, in another post you recommended 36 LED's for a tank 36x16x21 in a 12x3 pattern with 80 optics.

 

Perhaps 2 (or 1) of these: 36 DIY kit from Rapid LED using the XPG-R5 and XP-E Cree's. See if I can sub Royal Blue instead.

I'd have a few extra and room to add some UV down the road. Violet UV 3W LED from Rapid?

There is a 48 LED kit as well. Which is the better option? I'm leaning towards the 48 at the moment ... price and 9 inches to spread the light. I would use a mix of 80 and 60 optics ( maybe a few 40 towards the front for the clam). Also thinking about adding in a string of NW +B+ ? with the 48 kit down the road as the LED movement evolves.

 

I definately wish to avoid "over thinking" this project....lol like I can avoid that.

I would also plan to duplicate (make another for a total of two) this array for use over a 125 in the future.

 

Thanks in advance.

 

64 that may be overkill I think.

 

48 actually 42 as a base

 

48 with some NW added on a separate string

Edited January 10, 2012 by Mojorizn

[blasterman]

My intuition (which is not always but usually darn close) is to go with the 48 kit and two sinks. Two sinks are simply easier to manage and more flexible to mount than a single sink. on a 36" tank a 30" sink should work fine and give you more room to work under the hood.

 

Go with 80degree optics given the close spacing under the hood. Actually, Rapid's 80degree optics are pretty narrow anyways and not a whole lot different than their 60's in my opinion.

 

Biggest thing I would change is the spacing. You really need to cluster LEDs very close together to avoid color problems. If you go with a classic 50/50 royal/cool white then simply run the LEDs in pairs about 1/4 apart" and the top of your acropora won't look like it's being buzzed by one of NTI's from 'The Abyss'. Seriously...you'll thank me later for this.

 

If you run two rows, then you have the option to run another string in the middle to play with colors. Frankly I'm not sold on mixing cool white and neutral white because you end up wasting a lot of LEDs, but I'm not opposed to it if you really want the added complexity. For acropora growers a few standard cool blues running bare with no optics prolly adds the most impact with SPS if you're a deep color guy. No more than four cool blues total for that tank.

[Mojorizn]

Thanks for the reply.

 

Seems the 1:1 ratio of RB / CW is out and the 2:1 ratio of RB / NW is in favor.

Is this more for non-dimmable drivers, or is this the new standard?

I'm about half way through the LED Aesthetics thread now ...

 

So with that in mind, I would be looking at 36 RB and 12 NW in a two row cluster fashion.

Back to sketch up I go.

 

Down the line, toss in a row of 4 CB down the middle ... brings up another issue:

The Mean Well ELN's drive 5-8 or 8-14. I'd go with the 5-8 (i guess) but 4 CB's leaves me one short. Think I could get away with 6?

 

Lastly, if I go with the two row clusters 2RB/1NW what are your spacing recommendations between clusters and rows and would you stagger the rows at all?

 

Thanks again -

[Mojorizn]

If I go with the 48 kit, a 6 or 7 inch x28 inch heat sink with the 2:1 RB / NW in clusters, two rows in a 3 inch spacing between clusters and rows I came up with this.

Im open to suggestions for the center string ....

Its to scale...best i can get anyways. Tank is 36x18x24. Fixture will mount 4-5 inches max off waters surface in my canopy.

 

 

Measured cones at 70 degrees to split the difference between 80 and 60

 

 

The kit comes standard with CW, but I can swap them for "Neutral White" if I want in any ratio and lens combination.

THANKS to MIKE at Rapid LED for the GREAT CUSTOMER SERVICE and quick replies.

 

Specs for the Neutral White

Min. lumens 122 @ 350mA

1500mA max. drive current

3,700-5,000K color temperature

CREE part number XPGWHT-L1-0000-00FE4

 

On a side note..I'll hang on to a couple T5's from my current setup ... just for kicks and if needed.

 

Lemme know on that and I'll consider it a done deal.

 

THANKS

Edited January 10, 2012 by Mojorizn

[blasterman]

The debate between cool white and neutral white is purely subjective, and while I think I started the 2:1 royal / neutral combination it's certainly not a 'standard' in any sense. However, at the moment it's the more popular combination. Either work, but using neutrals will give you more color range, especially with LPS.

 

I give you kudos on the lighting diagrams, but in the real world acrylic optics we're using aren't nearly that predictable.That's why I hedge towards wider optics rather than tighter ones. The wider the optic the more tolerance there is for overlap. FYI - the last 80 degree optics I got from RapidLED were closer to 60 degrees.

 

Layout looks good. SPS in the middle of the tank and up highest might look a tad warmer with the royals pushed towards the outside, but it shouldn't be a big deal.

 

Standard blues used sparingly are the dirty little secret for lighting, especially SPS because standard blues give a bit of that halide 'bite' to a tank that royals don't. With smaller builds they are a pain because you only need a few of them or it's a trip down Windex lane, but with bigger builds they are easy to mix in and do help. Plus, with your build you can add them later right down the middle given they have no bearing on the current ratio.

[Mojorizn]

Thanks again for the input. I just used 70 as a happy medium ... I'l use mostly 80 where needed if I use any at all.

I plan on keeping 2 of my T5's in the canopy as well with perhaps a Fiji and UV combo .... work on the center string later.

 

Layout looks good. SPS in the middle of the tank and up highest might look a tad warmer with the royals pushed towards the outside, but it shouldn't be a big deal.

 

Then would you flip the configuration, or am I over thinking at this point?

 

One last question. I would want to mount the drivers/dimmers in my stand which will give me about a 5-6 foot run to the array. Will this present any problems with amperage or voltage drop? I'm electrically challenged for sure, but I think I remember reading something about that round 100 pages ago.

Edited January 12, 2012 by Mojorizn

[GravyReef]

<snip>

Edited January 14, 2012 by GravyReef

[TankRazr]

I've been reading this board off and on for quite some time and would like to distill some info regarding current trends so I can finally move forward with a build utilizing the best and latest methods.

 

The project will be to light a 40 gallon long. The dimensions for those not familialr are 48" long, 12" front to back and 17" tall. keeping some monti digi's and caps, anemone, zoo's, birdsnest, pociliporas, styloporas and somte others currently under wavepoint 4x54 t5 5" above tank.

 

Here is what I'm thinking:

 

2 separate arrays for each side of the tank consisting of a 2:1 ratio of blues to whites. So 10 or 12 blues and 6 or 8 whites per side.

 

Beyond using a 2:1 ratio what is the current trend leaning towards; cool white or nuetral white? Blue or royal blue? Combos of both? I'm looking for a little more perspective from others in addition to the recent previous posts.

 

I have 15 Cree cool white xp-g's and 18 cree xp-e's on hand to start with so will most likely be using them, but want to hear peoples opinions before committing them to the build.

 

I would like to be able to use the least ammount of dimmers possible.

 

So I'm looking for a driver suitable for running 20 or 24 cree b/rb's (or other) on their own channel and a dimmer suitable for running 10 or 12 cree cw/nw's (or other) on their own channel.

 

I would also like to make them dimmable. I would also like a dimmer that I may be able to control (in the future) with something like an arduino.

 

Your thoughts on Mean Well's, Thomas research, inventronics or other?

 

Thoughts on height over tank or optics?

 

Thanks folks

Edited January 15, 2012 by TankRazr

[sammy113]

For anyone working with meanwells ELN 60-48D in a small LED rig, this might be usefull for a clean installation. I managed to install the 10k Pot inside the driver. Pulled the white and blue wires from the inside and pushed the 10v ac adapter wires from the outside end of the factory cable. Cut some wires, drilled the top case and voilá. Also to prevent attaching the 3 prong power cord to the piece of wire the meanweall has, I replaced the whole cable with the long one so there are no nasty unions or wire connectors exposed. Here some pictures.

[Biglen]

So I have been asked to do this a few (hundred? )times now, so I figured I would get it out of the way. Hopefully this will provide some education to those looking to dabble in the world of high power LEDs.

 

If you asked for this, here it is. If you didn't, well you're getting it anyways

 

Go grab a cup of coffee, hit the bathroom, you are going to need it. Don't worry, I'll wait.... Back? Ok. This is a lot of information, but it's useful. Making educated decisions on how to build your LED array will save you time, money and headaches in the future. Put it this way, I did all the hard work for you. You just have to read it.

 

DISCLAIMER: This involves the use of tools that can hurt you, and electricity that can kill you. Please be careful. We would like to see you back here again showing off your new LED setup at some point. Missing limbs and burned off eyebrows won't get you bonus points. I have tried to explain everything here as clearly as possible and as safely as possible. I hold no responsibility for you hurting yourself or others.

 

 

 

 

First things first. This will be addressing high power LEDs only. 5mm, 8mm, and 10mm LEDs are just not powerful enough for most applications. There are some instances (like fuges, algae scrubbers, and very small pico tanks) where they can be used, but when it comes to most applications, they don't cut the mustard. I will be writing up another thread addressing the differences between the different sizes here soon.

 

Many of you have posted question on this forum like "I want to get into LEDs, but I don't know what to get", and "I know what parts I need, but I don't know how to wire them up". These are the kind of questions that will be addressed here. I'll divide this into three parts; "Why Use LEDs", "Parts You Need", and "How To Put It All Together".

 

This article will be updated continuously as new tecnologies and part options become available. It will also be updated to correct any goofs that I make. Hey, I'm not perfect

 

Update History

2-17-09 Initial Release

3-17-09 Added Recom driver to the driver list

3-25-09 Added Meanwell ELN series drivers to the list

2-16-10 Added info on Cree XP series LEDs. Added discontinuation note on Luxeon LEDs.

7-28-10 Added Rebel ES, c, and Altilon lines to Luxeon LEDs. Updated Rebel datasheet links

 

 

 

Why Use LEDs

 

We have all seen LEDs before. They are everywhere in our society in all kinds of modern technology. But why use them in our aquariums?

 

Up until recently, we weren't able to use them effectively to light up a tank. Too expensive, and just not powerful enough. But in recent years there have been great advances in the area of high power LEDs. Now, what makes a high power LED different from those that we find in our electronic devices?

 

First thing thats obvious is the amount of power used. Typical high power LEDs come anywhere from 1 watt to 3 watts, where your average 5mm LED is around 1/4 watt or less (8mm, 10mm and Superflux LEDs can go as high as 1/2W). With this high power comes increased brightness, but also increased heat. This increased brightness, which is many times more than 5/8/10mm LEDs is important for penetrating the water to greater depths. Another advantage is that they can generate more light over a wider angle. This is a clear advantage over smaller LEDs, as usually manufacturers will make the angle tighter to generate higher brightness numbers, and are usually so tight that they create what I like to call a "spotlight" effect, which it basically is. Currently, the top end high power LEDs are right behind metal halide and T5 in terms of efficiency, so you can produce almost as much light (lumens) for the same wattage.

 

But producing light, lumens in this case, is not what LEDs are all about. The real clincher is the ability to produce more PAR (Photosynthetic Active Radiation) per watt than most any other form of light. For those that don't know, PAR is a measurement of the amount of light that falls onto an area, that falls on a response curve for photosynthesis (400-700nm, ignoring UV and IR light). Basically what this means is that more PAR equals more growth out of photosynthetic corals. Because of this, LEDs do not have to produce as many lumens as other forms of light to reach the same growth potential. This also means less power is required too.

 

The next major advantage is heat. Now, I'm not going to say that these LEDs don't produce heat, as they do, and quite a lot of it. But what makes this different is where the heat is radiated from. Usually in most lights, heat is emmited from the bulb itself in the form of infrared light. LEDs do not emmit infrared from the emmiter and will not directly transfer heat into the tank like a metal halide bulb would. The heat that is generated comes off the back side of the LED. Usually, they are mounted to heatsinks to effectively control the heat, and radiate it into the air. Without additional heat placed into the tank, there is now less of a need for chillers and additional fans to cool the tank, saving you money.

 

LEDs can also save you money long term by elliminating bulb replacement. Most high power LEDs are rated to live for 50,000 hours before the light output drops to about 70% of the original rating. Thats a long time. With a light schedule of 10 hours a day, these LEDs could effectively last for over 13 years! The price you pay upfront is going to be more, but it could pay for itself within the first few years of ownership.

 

Another benefit of LEDs is the fact that they can easily be dimmed and controlled. Can you imagine being able to change your color temperature on the fly, going anywhere from 6500K to 20,000K? It's pretty cool. I realize that there have been new prducts released recently for T5 that allow dimming control, but I'm sure at quite a cost. Controlling LEDs can actually be quite simple, but also allows for some more complex setups and effects that you simply can't do with any other lighting source.

 

So as you can see, there are some very compelling advantages to using LEDs for aquarium lighting. The upfront costs will be more than most lighting setups, but the savings long term between heating and cooling costs, running costs (ie. less power to operate, less equipment to run), equipment costs (ie. removing a chiller out of the equation), and maintenance cost (bulb replacements) can make up the difference is a short period of time.

 

So how do you get this going?

 

Parts You Need

 

 

LEDs (Light Emmiting Diodes)

 

The obvious thing you are going to need here are LEDs. There are many different manufacturers, models, shapes, colors, and mounting options. Some are a little easier to work with than others, while some are easier to get. The main brands that get used the most for DIY purposes are from Lumileds (Luxeon), Cree, and Seoul Semiconductor. I'll break them down here in detail.

 

Lumileds (Luxeon)

 

Probably one of the more well known companies in the high power LED game, they practically pioneered the industry years ago with the introduction of the Luxeon I, III, and V series LEDs. While not the most efficient nowadays, they paved the way from what we have now.

 

Their models include:

• Luxeon I
  
• Luxeon III
  
• Luxeon V
  
• K2
  
• K2 TFFC
  
• Rebel White
  
• Rebel Color
  
• Rebel ES
  
• c
  
• Altilon
  

 

The K2, K2 TFFC and Rebels are the LEDs that we are going to focus on from Lumileds. These are the newer generation of LEDs and have much higher efficiency and output in comparison to their older siblings. The K2 got Lumileds back in the race after Cree and SSC started cranking out some seriously high power LEDs. But they weren't without flaws. With the high drive currents used by the K2, they generated a lot of heat. The K2 TFFC fixed a lot of the problems by using technology that was developed for the Rebel. This brought output back up to where Cree and SSC are currently, and brought heat levels down.

 

Now the Rebel is the odd duck of the family, but not one to ignore. All the other LEDs are much larger in size, and are more easy to work with when they are not mounted to a pcb. The dedicated solder tabs make attaching wire much easier. The Rebels on the other hand are SMT (Surface Mount Technology). Think of all the tiny little chips that are soldered to PC motherboards and most modern electronics. They are very small, and with the solder pad under the LED itself, makes for a tricky package to work with. BUT, if you can get past that, you have the ability to create very high density arrays, that are very bright. It also gives the opportunity for great color mixing, which we will get into later. The current generation of Rebel LEDs are just about as bright as the best that all manufacturers have to offer.

 

All Luxeon LEDs are available in multiple colors to suit the needs of you application. Most of the time you will be focusing on cool white, blue, and royal blue.

 

NOTE: As of March 1st 2010, Lumileds is stopping all sales of all of their high power LEDs with the exception of the Rebel. That will be the platform that they will be using for all future products.

 

 

Cree

 

A relative newcomer to the game, Cree has made a big splash by releasing some of the most powerful LEDs on the market. They are one of the most common LEDs that we end up using for DIY projects, mainly for their cheap availability from Asia, and their high output. Their models are covered under the XLamp brand and include:

• XR-E
  
• XR-C
  
• XR
  
• MC-E
  
• XP-E
  
• XP-G
  

 

Most of the Cree products that we are going to use are XR-E and XR models. The XR-E series has all the new super bright white LEDs, including the P4, Q2, Q4, Q5, and R2. These are brightness bins, that I will explain in the next section, but for right now, all you need to know is that the Q5 is the most common, and second highest brightness out of the lot. The XR series is used by us mainly for the blues. Idealy, the XR-E blues would be better, but are not as common, or as cheap as the XRs. They do work out quite well though.

 

The MC-E series is new, and is king of the hill in brightness in the Cree camp, but isn't particularly practical in our application. Because of it's extreme brightness, it makes it harder to effectively raise the color temperature with blue LEDs, and still get good color blending. Using an LED like this for spotlighting certain show corals, which is a very popular approach used in Japan, could be a good application for it.

 

Just like the Luxeons, most all of the different models are available in multiple colors, except the MC-E, which is only available in white.

 

UPDATE 2-16-2010: In recent months, Cree has stepped things up in the small form factor market to compete with the Luxeon Rebel. The XP series has been around for a little while now and is making some pretty significant strides in output and efficacy. The latest LED, the XP-G is Crees highest output single die LED, capable of lumen outputs north of 400lm when driven at 1500mA. The newly released XP-E royal blue is equal in output to the XR-E royal blue, but a fraction of the size. What makes these LEDs very interesting is that they use the same optics choices that have been available for the Rebel. There are still some critical lens angles missing that are preventing these from becoming a complete replacement for the XR-E, but it won't take long.

 

 

Seoul Semiconductor (SSC)

 

SSC is in kind of a strange situation. As of late, they do not actually make the dice (the part of the LED that actually emmits light) that they put in their LEDs. They actually buy them from Cree and repackage them. This make their performance very similar to the Cree equivalents. The models that are most common are:

 

• P4
  
• P7
  

 

The P4 LEDs are the equivalent to the Cree XR-E LEDs. The biggest difference is in the viewing angle of the LED, which is greater on the P4. This doesn't mean it's a benefit. The smaller viewing angle on the Cree LEDs means that more light is pointing into the tank without the need for optics. The SSC LEDs are also not as common on the marketplace for DIYers to get a hold of.

 

The P7 is very similar to the Cree MC-E, and as a result, shares the same problems with using them in aquarium applications.

 

 

 

These are by no means the only companies that make high power LEDs. They are just the companies that make the highest power, most efficient and easiest to obtain LEDs that are suitable for our hobby.

 

 

Constant Current Drivers

 

This is where things take a little departure from what you normally know about electrical devices. Everyday items like incandescent bulbs, motors, electric heaters, etc. are all what are called "voltage driven" devices. What that means is that the voltage to operate the device is kept constant, but the current required can change depending on what is needed. A motor is a great example of this, as when it is running with no load, the current is quite low, but as soon as you start to load the motor, or stall it completely, the current skyrockets while the voltage stays the same. An LED is a "current driven" device. The concept is the same as a voltage driven device, but it's the voltage that now changes and the current stays the same. This is very important in the long life of the LED because when the current increases on an LED, so does the heat. Once an LED gets too hot, it can be destroyed, or have it's overall life and performance severely reduced. I will go over some of the common LED drivers.

 

Luxdrive Buckpucks

 

Buckpucks are probably one of the most versatile drivers on the market right now. On top of their really small size, they offer a wide variety of options to suit your needs.

 

• AC or DC models
  
• 350mA, 500mA, 700mA, or 1A output
  
• Non-dimmable, on-board dimmer, or external dimmer options
  
• Wire lead or pin header connection options
  
• Up to 32v operation
  
• No additional cooling required.
  

 

All of these will require a power supply, and will not run directly on mains power, even though some are AC rated (low voltage AC). These are a great little driver for the money. Luxdrive also has a number of other models that are good for other applications, but the Buckpucks work the best for aquarium lighting.

 

 

Advance Xitanium

 

Advance Transformer, who many of you might be familiar with their PC, T5 and MH ballast, make a line of LED drivers under the Xitanium brand. They have a good selection of different models that can handle varying amounts of power and LEDs. What sets these apart is that they are one of the few drivers that can be powered directly from the mains.

 

• Multiple output current options
  
• Dimming capabilities (only on certain models)
  
• Mains power
  

 

 

Deal Extreme and Kai Domain Drivers

 

 

Both companies offer numerous different drivers that may fit the need for your application. The have a number of AC and DC rated units. Unfortunately, neither seems to have that one driver that does it all, none of them are dimmable, and most are low power. For smaller arrays, like fuge lights, there are some great AC drivers. There are some great small DC drivers too for you flashlight guys. While there isn't that magic driver, the super low cost on some of these can sometimes make up for it.

 

Recom RCD-24

 

A new driver on the market that seems pretty interesting. Similar in size to the Luxdrive Buckpuck, it holds many similarities, but could have some advantages.

 

• 350mA, 500mA, 750mA, 1000mA, or 1200mA output
  
• Non-dimmable, or external dimmer options
  
• Seperate analog and digital inputs.
  
• Wire lead (non-dimmable) or pin header (dimmable) connection options
  
• Up to 36v input
  
• Up to 32v output on 350mA, 500mA and 750mA models. Up to 30v output on 1000mA and 1200mA models
  
• No additional cooling required.
  

 

These will require a power supply, and will not run directly on mains power. These are reasonably priced, and competitive with the Buckpucks. It will require a little more work to get running than the Buckpucks, as the potentiometer is not included, and does not provide a 5v reference voltage to supply the analog input. Easy to fix, but a little more work

 

Meanwell ELN-30 and ELN-60

 

A new line voltage driver that is showing some promise. Similar to the Xitanium drivers, these have the advantage of higher current capacities, and higher output voltages for more LEDs per driver. All models of this driver have an option for dimming capabilities, unlike the Xitaniums.

 

• 30W or 60W output, with multiple options for max voltage and current
  
• Non-dimmable and dimmable (via analog 0-10v or pwm, but pwm is easier to get)
  
• Onboard pot for max current setting, independant of the external dimming control
  
• 90-264VAC operation for worldwide usage.
  
• Overcurrent and short circuit protection
  
• Sealed to IP64
  
• No additional cooling required.
  

 

While a very good driver on paper and in practice, availability is going to be the tough one here. The non-dimmable versions are readily available and can be had for a very good price. The dimmable ones require hand modification by Meanwell USA and adds a little lead time to the delivery. It also adds a good amount of cost for small quantities. Larger quantities makes the price a lot more reasonable once you get past a certain price break point.

 

 

DIY Drivers

 

Not many people are going to get into this end of the DIY spectrum, but there are options out there for those feeling adventurous. Some of these I have even used myself with varying levels of success.

 

• LM317 based current regulator. Simple, cheap, but generates a lot of heat.
  
• Transistor based LED driver. Another simple design thats cheap to build, but make a lot less heat.
  
• Simple buck regulator. Most efficient of these designs, but also the hardest to work with because of SMT parts. Best for use with controller designs.
  

 

 

 

These are the most common ones. There are many more that have different features including DMX control. I will update this list as more become available (or you guys tell me about them).

 

 

Power Supply

 

Not much to this one. If you are running a DC or low voltage AC driver, you need one. If you are running mains power, you don't. There are a few different types though if you do need one.

 

• Linear Unregulated. Big, heavy, and expensive (for the high power ones). They do give some of the cleanest power output though, but the voltage can wander if the input voltage changes. Usually open frame (parts are exposed).
  
• Linear Regulated. Same as the unregulated ones, but has much tighter control of the output voltage. This is what you usually find in cellphone chargers (wall wart).
  
• Switch mode. Much smaller for the same power as a linear power supply. Typically found in laptop power supplies. These can come open frame, industrial, and desktop (line lump).
  

Different voltages and current outputs will be determined by the array that is going to be powered, and the drivers used.

 

 

Heatsinks

 

This is probably the most important support component for an LED array. Like I mentioned before, high power LEDs do produce heat, and this needs to be removed and controlled. Overheating LEDs is a sure fire way of shortening their life, so picking out a good heatsink is critical.

 

Heatsinks can come in all different shapes, sizes and materials. Small arrays, using low power LEDs can get away with something as simple as a thick aluminum plate. Larger arrays will need something considerably bigger. There are three elements that make up a good heatsink:

 

• Material
  
• Mass
  
• Surface Area
  

 

Common materials are usually aluminum and copper. Both have advantages and disadvantages, but aluminum is the typical choice for this application. While copper has a greater ability to pull heat away from a heat source, aluminum is far better at actually getting rid of it (rejecting). Aluminum is lighter and cheaper than copper, and also doesn't corrode as easily as copper does. A large, high fin count copper heatsink would ultimately be better than most aluminum heatsinks, but the cost would be astronomical.

 

The mass of a heatsink plays into its ability to pull away and store heat. This can be important for an LED array. A heatsink with low mass can be saturated with heat very quickly, making it hard for a fan blowing air across it to keep up with the load. Think of the mass like a buffer. It takes longer for a high mass heatsink to saturate with heat, and the fan can more effectively keep the temperatures lower.

 

The surface area of a heatsink is also very important. Surface area is usually seen the easiest by high fin count. PC heatsinks are a prime example of this. The more surface area you have, the more area there is for heat to be transfered to the air, and taken away. Lot's of fins doesn't mean better in some respects. With fins very close together, it takes much more air flow to effectively remove the heat away from the heatsink, and more airflow can often lead to more noise. It also does not work well for passive cooling (no fan). At the same time though, very few fins hurts performance by not having enough surface area to remove heat. It can be a tricky ballance, but if you go on the side of caution and get a heatsink that you probably know is too big, you are probably going to be ok

 

Some of you that have looked into this before may have seen a measurement of heatsinks called Thermal Resistance. This is basically a measurement of how well a heatsink can transfer the heat from the load to the air. It's a combination of all the features I listed above. Lower is better in this case, but you can spend hours trying to find the right heatsink with the lowest thermal resistance.

 

Heatsinks can be found in a number of different places. PC heatsinks can work well for arrays that concentrate light into a smaller area, but are usually quite tall and can be difficult to hide in a hood. Ebay is a good source for reclaimed industrial heatsinks of all kinds of different sizes. There are also online retailers that deal with many different shapes and sizes of heatsink that can work for your application.

 

 

Optics

 

Optics are not one of the parts that you will need in every application. The whole point behind them, whether they be reflectors or lenses, it to focus the light into a smaller area. These start to become more important for tanks over 12-14" tall. The amount of light at 12" is considerably less than at the surface, and it gets exponentially worse the deeper you go. Optics can help bring the performance back up to usable levels for deeper tanks.

 

Optics come in a wide variety of angles, from very narrow (4 degrees) to quite wide (50+ degrees) and even different shapes (oval beam patterns). Most of these aren't very useful for the most part, and only the optics in the 25-80 degree range prove to be the most useful. A tighter optic will have better performance at depth than a wider optic will, so thats something to keep in mind. Conversely, a narrow optic will require closer spacing of the LEDs to get enough overlap to stop spotlighting, and may require more LEDs to cover the same area.

 

Based on recent test, I have found that 60 degree optics have the ability to reach 150W MH levels when LEDs are run at 1000mA. 40 degree optics can reach 250W levels. These tests were performed with Cree XR-E LEDs and optics.

 

All optics are designed for a particular brand of LED. A lense designed for a Luxeon K2 will not work well for a Cree Q5, and vice versa. It's important that you pick the right optic for the LED you decide to use. There are many companies that support all the big makers, so finding something that will work for you should not be hard. Some of the vendors include:

 

• Fraen
  
• Cree
  
• Ledil
  
• Polymer Optics
  
• L2
  

 

 

Tools

 

You aren't going to get much done without tools. There are going to be a few basics that you are going to need. Obvious ones for basic assembly are going to include:

 

• Soldering Iron (40W+, with a fine tip. More wattage the better)
  
• 60/40 or 63/37 rosin core solder (easier to solder than the newer lead free stuff, 0.030" to 0.040" diameter is nice)
  
• Wire cutter/stripper (need to be able to strip small diameter wire like 26awg)
  
• Basic hand tools like screwdrivers, drills, etc.
  
• 26-18awg wire in multiple colors. Use stranded, not solid core.
  
• Thermal Paste/Epoxy
  
• Shrink tube and electrical tape. Don't skimp on this. Get polyolefin heatshrink, and 3M Super33 vinyl tape. HD and Lowes carries them.
  

 

Good soldering skill is going to be important for this. Search around for some basic soldering how-to's on the web, and get some parts to practice on. It's not hard to do, but does take a little practice to get it right.

 

When looking to buy a soldering iron, I would suggest something from Weller over what you can buy from Radioshack. They are generally better quality, and have better selection of optional tips. A high wattage iron from Radioshack will work in a pinch, but if you can afford it, go Weller. The reason I recommended a 40W+ iron is because of the heatsinks. Once you start applying heat to the solder pad, the heatsink is pulling that heat away, and not getting the pad hot enough to melt solder. The higher the wattage, the quicker the pad will heat up, allowing you to solder the joint while reducing the amount of time the LED is exposed to high heat levels.

 

Some additional tools that might be required, are things like a tap set. I use screws to hold down the LED pcbs to the heatsink, and I need to tap a thread into the heatsink. These can be picked up in sets or individually for not a lot of money.

[JayUK]

Wow I wish I had found this post 6 months ago lol.

I would just like to point out that if you ever think about going for a cheap copy of a Meanwell driver then don't. They get stupidly hot and I even had 1 where the plastic case was starting to melt. Meanwell drivers are the most popular for a reason and cheap copy's are a serious fire hazard.

 

Also there are copys of cree LED's which are ok but when put next to the cree LED's there is a big difference in the brightness.

 

The lesson is you get what you pay for lol

[Division50]

So, got the initial PAR readings and I'm immediately unhappy.. it turns out that I have WAY too much output. (not the problem I expected). We're swapping some of the whites with 660's, turning down the juice and adding a row of 450's.

 

Looks like with 18 LEDs on less than 24 Watts, I'm very near the output of a 1500w MH. This should be fun

[chrysanthy]

really a cool article,awesome project!

[tyty22]

i just ordered 36" x 8" x 9" mr aqua tank and I'm interested in lighting it with leds or t5s. I have priced it out and LEDS may only cost around $50-60 more upfront so it seems rather doable.

 

My questions??

will 18 LEDS, half royal blue half cool white, all on a 1.1"x36" heat sink give a good spread and color mixture? They will be on dimmable drivers but will that be over kill for a 9" deep tank?

[alexinoz]

Awesome - I'm looking at getting a 48 x 18 x 18 and this guide has been truly helpful.

 

Thanks so much for the awesome commentary!

[iprayforwaves]

I picked up some of the cheap $1.99 Red 660nm 700ma LEDs from the group buy. Gonna use them for lighting an ATS on a 40g breeder setup. They came with 60 degree optics glued on...

 

I think this may be too tight and intense for the ATS, which will be approx 3" from the LEDs. It looks like i could remove these optics if needed, but can someone tell me for sure? I only ordered 2 extra LEDs so I dont want to damage them trying to remove the optics.

 

thanks for input!

[iprayforwaves]

Here is the completed ATS fixture, with the 60 degree optics still on. I had to dim the LEDs down to get a decent pic, they are MUCH brighter at full power. I'll have to see what effect the optics have on the ATS.

 

If the optics are too tight for the scrubber, I'll have to swap the LEDs out with another brand, as I found another thread that seems to suggest these are the primary optics for these particular LEDs and removing them in not suggested...

Edited March 4, 2012 by iprayforwaves

[mrg02d]

Hey guys,

What are you all running your LEDs at (current)? Ive got a 20g tall tank with 12RB and 9CW leds over it. Ive got the RB at 600mA and the CW at 100mA. Im using CREE XRE 3W leds and no optics with the LEDs about 3in over the water. Should I increase or decrease the current? Ive got SPS corals midway in the tank.

 

Thanks,

Matt

[kirsto71]

I have recently finished building an LED light which is approximately 400mm x 600mm and has 50 3watt CREE XP-G leds running at 1000ma. My questions is in regards to heatsink temperature. I am currently seeing surface temperature on the heatsink at around 55 - 56 degrees celcius (~130 degrees fahrenheit). Is this OK or do i need to increase the airflow and try to get the temperatures lower.

 

Thanks for any feedback

[Jarhead]

I have recently finished building an LED light which is approximately 400mm x 600mm and has 50 3watt CREE XP-G leds running at 1000ma. My questions is in regards to heatsink temperature. I am currently seeing surface temperature on the heatsink at around 55 - 56 degrees celcius (~130 degrees fahrenheit). Is this OK or do i need to increase the airflow and try to get the temperatures lower.

 

Thanks for any feedback

 

I'm not normally involved in reef lighting, but if the LED die (the little chip piece that makes light) is under 90C, you should get an easy 30,000 hours. The real question though, if the heatsink is at 55C, how good is your thermal transfer from the die to the heatsink. For the LEDs themselves, from the die to the package thermal interface is specified by the vendor in C/W. If you are running at 1000mA, you have just over 3W (LED Vf ~3.2, * 1 Amp= 3.2 W per device). 3.2W * 4 C/W = a temperature rise of 12.8 degrees C. So if the package thermal interface (the backside of the XP-G) is at 70C, then the die will be sitting at 82.8 degrees Celcius. Just because a board is MCPCB, doesn't mean the thermal resistance from the backside of the LED to the metal part is low.

 

Many MCPCBs have over 10 C/W. So, if your heatsink is 55C, then you'd have 32 degrees C rise in the MCPCB, and the backside of the LED would be sitting at 87C, which would mean the die inside of the LED is at 99.8C. At this temperature, the light output and the tint would definitely be impacted.

 

However, you can get higher end MCPCB with 3 C/W of thermal resistance, and even lower with fired ceramic on aluminum MCPCB (the ceramic takes the place of the FR-4 or other PCB material). There are also boards that have high density packed vias that contact the backside of the LED thermal pad, and transfer the heat to a heatsink, and usually they will use special 2 to 4 oz copper plating in the vias- These can get the thermal resistance down to 1/4 C/W. There are also metal filled vias where the copper actually fills the via solid, that can have even a lower thermal resistance yet. Another thing one can do is to make the PCB thinner, going to 0.031" instead of the standard 0.062", and the thermal resistance drops by half.

 

Another hint, is that the LEDs are more efficient when they are kept cool, and you will find a graph on the LED's datasheet that you can use for how much the output of the LED is decreased for a given die temperature.

 

There are a lot of design examples on the CREE site, here are a couple:

http://www.cree.com/products/pdf/XLampXP_sconce_ref.pdf

 

This is an example where they used super thin low oz. plated copper in the vias, they still got decent results:

"In general, increasing plating thickness during PCB production improves the thermal resistance of vias. In the example above, increasing the plating thickness to 70 μm (2 oz.) lowers the thermal resistance to 34 ºC/W per via. Consult your PCB manufacturer to determine if thicker plating is feasible."

http://www.cree.com/products/pdf/XLamp_PCB_Thermal.pdf

 

Life data at different temperatures:

http://www.cree.com/products/pdf/LM-80_Results.pdf

 

I have an array of sorted information, thermal resistances, thermal conductivity, LED testing and such here:

http://www.molalla.net/members/leeper/led.htm

 

 

I did some basic testing and teardown on one of the new Hi CRI, L-Prize winning LED bulbs here, that may be of use:

http://www.molalla.net/members/leeper/L%20prize%20bulb.htm

[jceh1]

i have an 8 gallon jbj half moon tank that is about 14 inches across and about 14 inches tall. I ave a tall 9-10 inch column of live rock as a certerpiece and a few small one surrounding it, It has an 11 watt power compact that I would like to replace with LEDs. There is presently a built in filter system with a spray bar and filter/media box that crosses the tank. I was thinking of taking that out, if necessary, as lit puses the CF light forward and I thought i might get better coverage without it. Thought of putting in hang on tank or canister. Plan to house dwarf seahorses so I can't have alot of current.

 

Is there any benefit to placing the lights in a half-moon layout, or can I get adequate coverage using the rectangular heat sink? will i have too uch light on the top of the live rock column and if so, how should I handle that ? Although I don't plan on keeping alot of coral since many are hazardous to dwarfs or fry, I want to be able to dim to create natural sunrise/sunset. Any thoughts and suggestions are appreciated.

[Mile_high11]

Alright, this is my first post on nano-reef, and it's a bit long, but here goes nothing.

 

I have read this entire thread...all 152 pages! I appreciate all the info and knowledge and feel like I can grasp the concepts enough to build my own LED light fixture to replace the modified Eclipse System 3 hood I have with one 65W PC 50/50. My tank is 29G with standard measurements of 30"L/12"W/18"D. I have LPS, zoas, and shrooms growing right now, but would like to try my hand at SPS in the upper 1/3 of the tank. My live rock is arranged in two towers, one on each side of the tank. I just built a custom canopy out of solid pine that is about 14" tall with an open back and vented top and allows me total adjustment for the light height and placement. (I will do a build thread with more pics/plans once I have finished with the lights).

 

I was planning on placing 24 LEDS in 2 rows of 12 on a 4.23"x20" heatsink from heatsinkusa. Color mixing would be 8 NW Cree, 12 RB XP-E, 2 CB XP-E, and 2 Violet UV XP-E. The NW and RB would have 60 degree optics and the CB and UV would have 80 degree. I would drive the 8 NW on a Meanwell ELN-60-48D with a 10K Pot for dimming and the 16 colored lights on another dimmable driver. Also on the fixture will be two RB moonlights, and all lights and drivers will come from Rapidled.

 

The lights will be arranged in two rows 3" between rows and the LED's placed in pairs 1/2" apart and 3" between pairs in this color arrangement:

 

RB - NW - CB - RB - NW - RB - RB - NW - RB - CB - NW - RB

ML ML

RB - NW - RB - UV - NW - RB - RB - NW - UV - RB - NW - RB

 

A few questions before I pull the trigger:

 

1. Is this an appropriate color mix or am I over thinking it with the CB and UV lights? I thought they may help with color "pop"

 

2. What is the best option to drive the colored lights? Should I switch to 10 NW and 14 colored lights so I could use two ELN-60-48D drivers or is there a better driver option for 16 LEDs?

 

3. Should I go with 8 of the XP-G lights or XM-L for the NW? I know you can power the XM-L higher, but is that overkill for a 29G? Plus they are twice as much money.

 

4. I planned to place the lights about 6-8" off the water. Are 60 degree optics appropriate?

 

5. How necessary is a splash guard? Does it need to be fully sealed or just block the front of the LEDs?

 

6. Last question...am I over thinking it or creating too much heat by pairing up the lights? I assumed it would help with color blending, but maybe it is unnecessary?

 

I just need a few of the experts to give me a quick affirmation or lend some advice before I blow a wad of cash. Sorry for the long post, but thanks so much for the help and all the info on this thread!

 

Attached are the pics of my current setup and the new canopy I built