Minimalistic multichip DIY LED build

[maglofster]

Originally Posted by dn100

Hi Maglo what coolers are you using on your 10 W 16 K chips ?

For that build I used a heatsink from heatsinksusa.com (you can check it out in my Elos tank thread, it's a couple of pages into the thread).

[maglofster]

Originally Posted by dnejdl

man i wuld love to see some par readings on them !!!

A friend of mine is doing the same build (using a tower model VGA cooler, but the same multichips) and he's got a nice PAR reader so pretty soon I can probably publish his results.

[reefnut2012]

Subscribed. This is more like it. LED is evolving fast

[maglofster]

[007Bond]

Maglofster,
Thanks, your video was easy to follow. I'm having a hard time coming up with questions.---Rick

[stormrider27]

First of all your English is excellent! On top of that your step by step instructions are superb, I can wait to see your next video! Have you or have you heard of anyone supplementing the multi chips with single chips like Royal blue for accent lighting? I wonder if you can use multi chips to get a spot light effect like how many Japanese Reefers use PAR 38 lights. I really like the shadow effects you can get with PAR 38......

Thanks again for a first class DIY video!! -Mark

[maglofster]

Thanks guys!

Yes you can definitely use lenses with a tight beam to get accent lighting. A reefer I know back in Sweden has created a tank with a single reef pillar with sps. The whole tank is dark except for the lighted pillar.

I have not seen ppl using single chips for accent though, but I have seen people using 10W RB's for that.

[maglofster]

BTW, this is a close up of one of my multi chips, you can see how the individual LED's are connected in both parallell and series into something like a grid.

[007Bond]

Question, the rule of thumb for 3w leds is L X W / +-16 to find the number of leds you will need. How do you figure the number of multi chip leds you will need on your tank?---Rick

[bigguyuk]

spot on fellow well done
were did you get the big heatsink with fans from ?
Simon

[Phishguy]

Great video!! A few questions about your heatsinks and leds. First, I had been looking at these leds before and I never found out if they are rated at their actual wattage or equivalent wattage. For example, on ebay, the 100w chips have a forward voltage of 36vdc. Does this mean they are 100w equivalent? Also, where did you find those active heatsinks? Are they overkill? Thanks

[dnejdl]

any big computer web site will these heatsinks

[maglofster]

Rick! I would say basically the same formula, just keep in mind that you have to figure out what wattage the individual LED's have and adjust the formula accordingly.

For example the 50W LED's are built by 50 x 1W LED's. The one's I'm calling "100W multichip" are built by a hundred LED's that can go from about 1W to 2,5W each.

So for example 24"x12"/16=18 18x3W=54W Okay, for this tank i would go with smaller multichips perhaps 8x10W or 4x20W and just dim them down a little.

Or for a 48"x22"/16=66 66x3W=198W So I would go for 4X50W mixed cool white/rb and probably 4x10 pure RB to use as dawn/twilight lights.

[007Bond]

Originally Posted by maglofster

Rick! I would say basically the same formula, just keep in mind that you have to figure out what wattage the individual LED's have and adjust the formula accordingly.

For example the 50W LED's are built by 50 x 1W LED's. The one's I'm calling "100W multichip" are built by a hundred LED's that can go from about 1W to 2,5W each.

So for example 24"x12"/16=18 18x3W=54W Okay, for this tank i would go with smaller multichips perhaps 8x10W or 4x20W and just dim them down a little.

Or for a 48"x22"/16=66 66x3W=198W So I would go for 4X50W mixed cool white/rb and probably 4x10 pure RB to use as dawn/twilight lights.

I see, makes sense. Thanks

[maglofster]

Originally Posted by Phishguy

Great video!! A few questions about your heatsinks and leds. First, I had been looking at these leds before and I never found out if they are rated at their actual wattage or equivalent wattage. For example, on ebay, the 100w chips have a forward voltage of 36vdc. Does this mean they are 100w equivalent? Also, where did you find those active heatsinks? Are they overkill? Thanks

Thanks!

Well about the rating of the LED's. It's a mess.. The ones they call 100W actually consist of 100 individual LED's that can be driven from 1W up to about 2,5W but they still call it 100W.

The multichip I'm using (the large 100W) have a Vf of about 36V and a maximum current of 7A. So to calculate wattage I use the formula P=U*I. P=36*7. P=252. So 252W and if you divide that with the number of LED's you get the individual LED wattage 252/100=2,52W.

Im going to drive mine at about 175W i think. That would give me a wattage of about 350W over my 40"x40" tank which is 24" high. During peak hours I will also add an extra 100W 10K white. It may be to high, but we'll see.

[007Bond]

Originally Posted by maglofster

Or for a 48"x22"/16=66 66x3W=198W So I would go for 4X50W mixed cool white/rb and probably 4x10 pure RB to use as dawn/twilight lights.

For the 4x50w and 4x10w, its 240w total vs. 198w. Should you figure a higher total wattage on the multi-chip and then dim to your desired wattage?
How do you decide on the proper spacing/location of your chips? Thanks Again,---Rick

[maglofster]

I was thinking of using the RB's (4x10) only during dusk/dawn to create a blue light only. Not during "daytime". Just control them with a timer.

For spacing, try to just calculate an even distance between the lights and put them in a row over the middle line of the tank. To cool the 10W lights you won't need VGA CPU coolers. Just use passive aluminium heatsinks. Maybe a thin long one that you easily can hang up over the tank.

About the total wattage being a bit higher, don't worry. The LED's have a bit lower efficiency than the Cree ones. Maybe use a formula like: L*W/14 which gives (48*22/13)*3=243. But this is not scientific at all. We dont have enough facts and knowledge of the multichips yet.

Over my Elos tank, 48" by 22" I use about 280W LED's right now.

[007Bond]

I see, Thanks,
For lenses should I use the same as if I were using 3w leds? I was going to use 60 degree as the leds will be mounted in my hood, with a distance of 10" between the top of hood to top of water.

[maglofster]

Originally Posted by dnejdl

any big computer web site will these heatsinks

Exactly, please feel free to post a link to any good site in the US. I'm using sites in Sweden.

But for those of you wondering about the specific cooler I'm using, here is a link: http://www.arctic.ac/en/p/cooling/vga.html

[maglofster]

Originally Posted by 007Bond

I see, Thanks,
For lenses should I use the same as if I were using 3w leds? I was going to use 60 degree as the leds will be mounted in my hood, with a distance of 8" between the top of hood to top of water.

Yes, I would say not any tighter beam than 60 degrees or you will get the ol' Disco effect.. And yeah, dont use lenses for the 10W's if you decide to use them, it will be nicer with a very diffuse blue light I think.

This will take care of the 50W cooling: http://www.arctic.ac/en/p/cooling/vg...us.html?c=2182

[007Bond]

Originally Posted by maglofster

Yes, I would say not any tighter beam than 60 degrees or you will get the ol' Disco effect.. And yeah, dont use lenses for the 10W's if you decide to use them, it will be nicer with a very diffuse blue light I think.

This will take care of the 50W cooling: http://www.arctic.ac/en/p/cooling/vg...us.html?c=2182

Sorry, do you mean "not to use them it would be nicer?" and is the heatsink link for the 10w chips or will it also cool the 50w chips? Thanks---Rick

[maglofster]

I mean, use lenses for the 50W:s only. IF you decide to use the 10W RB's for dusk/dawn light dont use lenses on them.

The cooler I posted a link for is only for the 50W multichip. For the 10W chips you can use something smaller, like a passive heatsink without a fan.

[007Bond]

Ok!

[SUMMERS]

Thanks Maglo for the answers.

Good video. I caught everything except how many fans that wall wort will drive. :-)

I ordered two 9" heatsinks from rapid I was thinking of putting 2 50w lamps on each. You think one fan is enough on each heatsink?

Also do you like the coloration of the combo led vs one blue and one white? I have the one blue 50w over a 20 long and it covers the tank well without optics and makes the corals fluorescence very well but is too blue for my liking.




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[maglofster]

Originally Posted by SUMMERS

Thanks Maglo for the answers.
I ordered two 9" heatsinks from rapid I was thinking of putting 2 50w lamps on each. You think one fan is enough on each heatsink?

One fan is enough. What you should think about is what happens if the fan (when really) fails. If the passive cooling will cope, then no problem. Remember to push the airflow downwards against the heatsink!

Originally Posted by SUMMERS

Also do you like the coloration of the combo led vs one blue and one white? I have the one blue 50w over a 20 long and it covers the tank well without optics and makes the corals fluorescence very well but is too blue for my liking.

Yes, I like it very much! I think pure blue is also very attractive, but my SPS don't think so when it comes to growth. They need light at different wavelengths to really thrive. So for me the combo chip is the ultimate!