Minimalistic multichip DIY LED build

[gtfcniles]

This is the exact reason I am fond of this thread. I really want to switch to LED's and have a couple of options. I dont want to use Kessils so ReefLED DIY or this DIY chip thread is the crossroards I am at. I just have no idea what I would need for either option.


Tony

Just buy and experiment, that is half the fun!

I'll post my build thread of mine once i'm done, LEDs are on the plane as we speak and i'm back from work on wednesday so fingers crossed there will be some action next week!

 

[noplay180]

@lasse what type of heatsink did you use on the mix of leds

 

[ronreef]

Based on this picture it seems like the wattage closely follows the # of chips in the LED.

I bought this chip

and its advertised as a 20watt however i only see nine chips in the LED. Can someone explain this to me?

Thanks.

Each chip is overdriven to achieve a total of 20W of power.
20W/9chips=2.22W/chip

Each chip is driven to 2.22W using .616A through each parallel leg.
2.22W/3.6(Vf)=.616A

There are three legs for a total of 1.85A which is needed to achieve 20W.
.616A x 3 legs= 1.85A

 

[ronreef]

Ac-rc seems to be the only legit provider of good multichips that I've seen. At least you know what you are getting.

There just aren't enough multichip options for my needs yet though, and I wish there was. It would be so much easier to wire a multichip than wiring 50 leds on stars closely spaced together as much as possible, 3-UP and 4-UP chips are a bigger nightmare.

Epistar 3w leds by themselves just can't compare to a 3w XP-G2 or XT-E led in efficiency. 50 Cree XT-Es on stars for $2.50 each would cost the same or less than a 150w epistar multichip as well, would have much more lm/watt, and has the ability to include different color options that can be changed out at will. Cooling could be also be done with just fans and a heatsink instead of full cpu heatsinks on each chip. Disco effect would be more noticeable though.

There's no perfect solution yet, but I do like that multiple DIY led options are available. With MH and T5's, customization was down to just ballasts, reflectors, and bulbs. With DIY leds, we can design our own full fixture to suit our needs.

The LED's ac-rc sells on multichip panels are not 3W leds. Best case output power output using the absolute max foward current and max forward voltage for an ac-rc multipanel chip is 2.52W per chip. That's pushing the emitter to it's absolute limits. Something you typically would not do with these emitters. ac-rc emitter are typically run at ~1W sometimes double that.

There's also a die size difference between the two. ac-rc uses a 45x45mil die size. Whereas Cree's XPG2 uses a 55x55mil die size. Typically with an increase in size comes an increase in efficiency.

I'm unsure you're making an accurate comparison.

 

[tronyony]

Just buy and experiment, that is half the fun!

I'll post my build thread of mine once i'm done, LEDs are on the plane as we speak and i'm back from work on wednesday so fingers crossed there will be some action next week!

Unfortunatley I cannot just buy and experiment as fun as that would be. I need a good starting point and then go from there.

 

[bhazard451]

The LED's ac-rc sells on multichip panels are not 3W leds. Best case output power output using the absolute max foward current and max forward voltage for an ac-rc multipanel chip is 2.52W per chip. That's pushing the emitter to it's absolute limits. Something you typically would not do with these emitters. ac-rc emitter are typically run at ~1W sometimes double that.

There's also a die size difference between the two. ac-rc uses a 45x45mil die size. Whereas Cree's XPG2 uses a 55x55mil die size. Typically with an increase in size comes an increase in efficiency.

I'm unsure you're making an accurate comparison.

Comparison was value based, not spec based. We'll use 10000k as an example. 100 45mil leds in a 100w multichip can be matched in output (10000lm?) by 24 Cool White Crees, which would come the closest in color temp. (XT-E)

$125 1 multichip
$84 24 Crees (avg price $3.50, some are higher, some cheaper. Bridgelux, Epistar, or Luxeon 3W could be substituted for even cheaper by adding a few more leds to match output)

$500 4 multichips.
$336 96 Crees.

Other parts and factors come into play for a build... drivers, heatsinks, optics, ease of wiring, etc.. but overall right now it is cheaper, more flexible, and more efficient to create a 3w array over a multichip array.

 

[Lassef]

Lasse thanks for the advice asking with others i have not slept thinking about how i could get this started. How does glass euro bracing affect light

I do not understand what you mean with "glass euro bracing" Do you mean glass bars between front and back side or bars along front - side - back - side?

Okay how about 100watt 20000k in the center and 1 420 50watt and 1 455 50watt. or would I get a better blend surrounding with 20watt

I would prefer 20 watts around the center 100 W - 4 or 6

@lasse what type of heatsink did you use on the mix of leds

to my 9*10 watts I use a graphic card cooler xigmatek BIFROST. It manage to hold 35 C for around 90 W. Its not enough for you. You must have some one that manage at least 250 W or more. Here you can find some suggestions. I´m sure - there is more options.

Sincerely Lasse

 

[ronreef]

Comparison was value based, not spec based. We'll use 10000k as an example. 100 45mil leds in a 100w multichip can be matched in output (10000lm?) by 24 Cool White Crees, which would come the closest in color temp. (XT-E)

$125 1 multichip
$84 24 Crees (avg price $3.50, some are higher, some cheaper. Bridgelux, Epistar, or Luxeon 3W could be substituted for even cheaper by adding a few more leds to match output)

$500 4 multichips.
$336 96 Crees.

Other parts and factors come into play for a build... drivers, heatsinks, optics, ease of wiring, etc.. but overall right now it is cheaper, more flexible, and more efficient to create a 3w array over a multichip array.

The value in any comparable build is subjective. It's a personal thing. For me I'd rather wire up a couple multichips than 50 individual crees. To each their own. I believe I know what you're getting at though.

 

[Lassef]

The latest 42-45 mil LED can be driven at 700 mA instead of 300 mA. Thats the reason why AC-RC specify their 20 watts chip (with 9 individual LED) for 2000 mA. See ronreef´s calculation in post 1549.

My experience from several months with running "20 W" (with 9 individual LED) chip at 1800 mA are good. As for those 50, 60 and 100 Watt based on Epistars 45 mil LED I think ronreef is a bit too careful. Assuming that I have proper cooling, I would probably dare to at least take out 50% more Watt than the nominal 50, 60 and 100 watts. But one must be aware that the output of light per inserted watt becomes lower at higher currents than 350 mA per individual LED.

@ bhazard451. For me - it is not a question of price all the time. With multichip i can get more light and more smoth distributed in a smaller area (with lenses) and get it to penetrate deeper. And as long as Cree does not produce their XL-M in higher Kelvins, it is no choise for me. I have test cool white XL-M together with 10 watts multichip (10 - 16 000 K) and I found no reasons tho change my normal design.

Sincerely Lasse

 

[Lassef]

Hi everybody, this is a great thread! Thank you guys for starting it. I have read through the whole thing but still cant make an educated guess on what I would need to switch from 8x54 T5's to the LED chips. If some of you veterans could help me out that would be great.

-Tank is a 100g 60x18x20
-Current lights are 6x ATI Blue plus, 1x ATI Purple plus and 1x GE Daylight 6500K in a Nova Extreme fixture
-Distance from top of water to top of sandbed is 16"
-Distance from current lights to top of water is 7"

I have a mix of LPS, SPS, softies and fish

I would like to dim the blue and white separately and eventually control them with a controller

If you need any more info please let me know

Thank you,
Tony

It looks like a lot of blue

My choise in your case would probably be to work with 20 watts chip of the AC-RC type. With Meanwell HLG-80H-48B or HLG-100H-48B you can have 4 chip in a serie and at 1700 mA respectively 2000 mA (FV for 4 chip in a serie at 1700 mA is around 41-42 V; at 2000 mA probably around 44 V). I would probably not use lenses. An easy way to do a heatsink is to use a square aluminum tube. The one that I use is 2*50*25 mm but other dimensions works also. I my cases I use one 20 watt chip per 20 cm of this tube. See here for the principle.

I would start with two 150 cm tubes (25*50 or something like that), three fans at each tube (50 mm) and 8 chip / tube. White´s - a mix of 10 - 16 000 K) RB - a mix of 420, 445 and 455 nm. you seem to like the blue look so att least 1:1 or slightly more blues. And fix the dim option.

Sincerely Lasse

 

[noplay180]

@lasse my tank has 1/2 glass cross bracing which my center light would be over. What do you think the coverage would be on these lights

 

[Lassef]

If you have them around 10 - 15" over the surface I think that they will cover all of your aquarium - but I´m not sure.

The cross bracing is a problem - it vill not be damage but take away a lot of the ligth.With your design - you may not need to spread them out evenly. Or use two of this design and two blue/white 60 watts. I think you must do some test.

Sincerely Lasse

 

[noplay180]

So I'm going to start with 2 100 watt 20000k surrounded by 3 455 and 1 420. Then work about the ends after seeing what spread I get. cooling these two monsters will be next problem

 

[tronyony]

It looks like a lot of blue

My choise in your case would probably be to work with 20 watts chip of the AC-RC type. With Meanwell HLG-80H-48B or HLG-100H-48B you can have 4 chip in a serie and at 1700 mA respectively 2000 mA (FV for 4 chip in a serie at 1700 mA is around 41-42 V; at 2000 mA probably around 44 V). I would probably not use lenses. An easy way to do a heatsink is to use a square aluminum tube. The one that I use is 2*50*25 mm but other dimensions works also. I my cases I use one 20 watt chip per 20 cm of this tube. See here for the principle.

I would start with two 150 cm tubes (25*50 or something like that), three fans at each tube (50 mm) and 8 chip / tube. White´s - a mix of 10 - 16 000 K) RB - a mix of 420, 445 and 455 nm. you seem to like the blue look so att least 1:1 or slightly more blues. And fix the dim option.

Sincerely Lasse

Thank you kind sir! This is the info I was looking for. Now I'm not in the dark and can start planning my setup. I will for sure keep u posted on what happens with my build.


Thank you,
Tony

 

[tronyony]

Lasse,

Can u reccomend a starting point for a 125g mixed reef and a 250g mixed reef? U see I'm in the US Airforce and 4 of us in my shop have reef tanks. Myself and another guy have the same tanks and the other 2 have the sizes listed above. The 250g is 30" deep and 84" long and the 125g is 72" long. I

I didn't say earlier but my current t5's are 7" off the top of the water line. Would I need lenses?



Thank you again,
Tony

 

[bhazard451]

The latest 42-45 mil LED can be driven at 700 mA instead of 300 mA. Thats the reason why AC-RC specify their 20 watts chip (with 9 individual LED) for 2000 mA. See ronreef´s calculation in post 1549.

My experience from several months with running "20 W" (with 9 individual LED) chip at 1800 mA are good. As for those 50, 60 and 100 Watt based on Epistars 45 mil LED I think ronreef is a bit too careful. Assuming that I have proper cooling, I would probably dare to at least take out 50% more Watt than the nominal 50, 60 and 100 watts. But one must be aware that the output of light per inserted watt becomes lower at higher currents than 350 mA per individual LED.

@ bhazard451. For me - it is not a question of price all the time. With multichip i can get more light and more smoth distributed in a smaller area (with lenses) and get it to penetrate deeper. And as long as Cree does not produce their XL-M in higher Kelvins, it is no choise for me. I have test cool white XL-M together with 10 watts multichip (10 - 16 000 K) and I found no reasons tho change my normal design.

Sincerely Lasse

I want to make a multichip build, but I have no idea how to design it the way I'd like it, and be cost effective compared to what I have now.

How could I create a 14k like color, mixing in 450nm royal blue, with the added spectrum of warm white/neutral white, add 420nm violet chips into the mix... and have it properly blended, cooled, stay under 200watts, and fit onto an 18"-24" heatsink? I fear that they'll create different shades of color in different sections of the tank.

 

[ronreef]

The latest 42-45 mil LED can be driven at 700 mA instead of 300 mA. Thats the reason why AC-RC specify their 20 watts chip (with 9 individual LED) for 2000 mA. See ronreef´s calculation in post 1549.

My experience from several months with running "20 W" (with 9 individual LED) chip at 1800 mA are good. As for those 50, 60 and 100 Watt based on Epistars 45 mil LED I think ronreef is a bit too careful. Assuming that I have proper cooling, I would probably dare to at least take out 50% more Watt than the nominal 50, 60 and 100 watts. But one must be aware that the output of light per inserted watt becomes lower at higher currents than 350 mA per individual LED.

@ bhazard451. For me - it is not a question of price all the time. With multichip i can get more light and more smoth distributed in a smaller area (with lenses) and get it to penetrate deeper. And as long as Cree does not produce their XL-M in higher Kelvins, it is no choise for me. I have test cool white XL-M together with 10 watts multichip (10 - 16 000 K) and I found no reasons tho change my normal design.

Sincerely Lasse

I plan to run my 60W hybrid on up to >90W. I simply used numbers stated on the datasheet:

Typical voltage of 3.15V @ 350mA.

 

[tronyony]

Is anybody running these chips inside a normal canopy? I would like to if I can but if I need to build a new canopy for proper cooling I can too. Lasse recommended I use square tubing for my heatsink but at his dimensions I wouldnt be able to use my canopy. Is there a recommended heatsink size from heatsinkusa.com that can accomodate 8x20w chips?

I'm also in the same boat as noplay180 with the glass brace in the middle of my tank.


Thanks,
Tony

 

[mstags21]

Awesome project

 

[sfsuphysics]

My experience from several months with running "20 W" (with 9 individual LED) chip at 1800 mA are good. As for those 50, 60 and 100 Watt based on Epistars 45 mil LED I think ronreef is a bit too careful. Assuming that I have proper cooling, I would probably dare to at least take out 50% more Watt than the nominal 50, 60 and 100 watts. But one must be aware that the output of light per inserted watt becomes lower at higher currents than 350 mA per individual LED.

So what's the voltage drop across these "20W" royal blues? It says 10-11v, which to me says you could hook 4 of them up with a 48v meanwell (I happen to have these laying around)... ALMOST 5 could be run off one but that might result in some bad mojo happening with your driver as that's skirting the line of the 10v end of things.

Also is it just me or are the data sheets on the ac-rc page not working?