Help with DIY LED fixture - Page 2 - The Planted Tank Forum
Old 07-20-2014, 12:59 AM
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Quote:
Originally Posted by Amleen View Post
Thanks jeffkrol!

Can't find cyan leds, i'll search more.. The 660nm leds were already on the initial project, but I was so undecided on that..

Just a question on Typhon controller: can I dim two drivers with a single channel?
You can dim like 20+ LDD's on a Typhon channel. The dimming output on an LDD is 1ma. Max input on a Typhon is ~40ma.
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Old 07-21-2014, 09:54 PM Thread Starter
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THank you gus

These LDD drivers, will just deliver the necessary voltage to the leds? I mean, if a single driver gives an output of 30V, can I connect only few leds (3-4) without blow them up?
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Old 07-22-2014, 12:13 AM
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Quote:
Originally Posted by Amleen View Post
THank you gus

These LDD drivers, will just deliver the necessary voltage to the leds? I mean, if a single driver gives an output of 30V, can I connect only few leds (3-4) without blow them up?
Depends on the LED. To figure out how much you can do just divide 30 by the max forward voltage of the LED. That will tell you how many LEDs you can connect per LDD.

So for XM-L U2:
30V/3.1V = 9

XM-L2:
30V/3.05 = 9

So you can do 9 XM-L per LDD. I also highly doubt you will be running those XM-L at 1500ma that close to the substrate. Then if you go 60deg optics you can raise the light pretty high and run them at even lower power.

If I were you though I would look into clustering the LEDs into 3 clusters of 9 across that heatsink. Clustering will increase PAR substantially while getting rid of disco effect.
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Old 07-22-2014, 03:30 AM
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Quote:
Originally Posted by Amleen View Post
THank you gus

These LDD drivers, will just deliver the necessary voltage to the leds? I mean, if a single driver gives an output of 30V, can I connect only few leds (3-4) without blow them up?
The Ldd's (or any constant current driver or a "mixed mode" driver running in its constant current range.. sounds more confusing than it is) adjust voltage to draw the current you need.. In general it "controls" the voltage..thus controls the current.

One catch. Using a separate PS and an LDD you "lose" 3V..

A 36V ps and you can only get 33V max out of an LDD..

IF your LED's run at say 3.2V @ 1500mA you can only string 10.3 diodes
33/3.2
(well 10)
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Old 07-22-2014, 03:39 AM
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Quote:
Originally Posted by jeffkrol View Post
The Ldd's (or any constant current driver or a "mixed mode" driver running in its constant current range.. sounds more confusing than it is) adjust voltage to draw the current you need.. In general it "controls" the voltage..thus controls the current.

One catch. Using a separate PS and an LDD you "lose" 3V..

A 36V ps and you can only get 33V max out of an LDD..

IF your LED's run at say 3.2V @ 1500mA you can only string 10.3 diodes
33/3.2
(well 10)
LDD-L though is 30V output but you can input up to 36V. So he can only do 9 chips per drivers but he has 27 LEDs so it works out perfectly.
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Old 07-22-2014, 03:55 AM
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Quote:
Originally Posted by gus6464 View Post
LDD-L though is 30V output but you can input up to 36V. So he can only do 9 chips per drivers but he has 27 LEDs so it works out perfectly.
30v/3.1V approx....
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Old 07-22-2014, 06:07 AM Thread Starter
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Sorry, I know that my english is not perfect, but my question was a bit different (or perhaps I didn't catch the answer )

I'll make an example: if I'm using an LDD driver (or another constant current driver) and I'm using XM-L leds, I necessarily have to connect 9 leds or can I connect less, like only 3-4?
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Old 07-22-2014, 06:26 AM
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Quote:
Originally Posted by Amleen View Post

Sorry, I know that my english is not perfect, but my question was a bit different (or perhaps I didn't catch the answer )

I'll make an example: if I'm using an LDD driver (or another constant current driver) and I'm using XM-L leds, I necessarily have to connect 9 leds or can I connect less, like only 3-4?
You can do as little as 2 to a max of 9.

Sent from my XT1060 using Tapatalk
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Old 07-22-2014, 06:54 AM Thread Starter
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Quote:
Originally Posted by gus6464 View Post
If I were you though I would look into clustering the LEDs into 3 clusters of 9 across that heatsink. Clustering will increase PAR substantially while getting rid of disco effect.
With this, you mean that you would keep the leds closer one to another than I was planning?
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Old 07-22-2014, 07:59 AM
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Quote:
Originally Posted by Amleen View Post
With this, you mean that you would keep the leds closer one to another than I was planning?
It is not totally necessary, especially the higher from the water surface the light is..or the wider the light optics are. Most "on chip" lenses are 110 degrees or greater

"Clustering" colors and whites give a better blend, as their (if using 90 degree lenses) cones blend together..

This is an "on chip" example. It is called 'Ocean Coral White" and is 660nm red, cyan, and royal blue in a cluster (in this case all 3 on the same heat sink.)

Not so important w/ whites....
Any combination of red(ish) plus green(ish) plus blue(ish) blends to white..

another example of a DIY w/ blending:
Broad spectrum, fully controllable LED shoji lantern

Quote:
13 X cool white Cree XT-E
13 X warm white Cree XT-E
2 X 660nm "deep red"
2 X 475nm "deep blue"
2 X 495nm "turquoise"
On the above "I" would have doubled the color clusters..and ran each on it's own channel w/ possibly combining the royal blue and cyan so those would be either 2 or 3 channels.
Whites would need at least 2 channels or cutting down the amount and, depending on preference changing the ratio or ww/cw.. BUT that is a matter of taste. 50/50 ww/cw has a tendency to be too "yellow" looking for many.
A lot depends on the actual K value..

alternatives include red/ww on the same channel.. Blue/cw on another.. Leaving green/cyan on one more.. This creates a natural R(ish)/G/B(ish) blending capability..

but back to your orig question..clustering does help blending of colors.. and your spacing would only need to be adjusted accordingly..

Early build w/ 2-10W 660nm red and 15 warm whites in a row..

this is 4 660nm red, 7 3500k and 7 6500k LED's (3W)(the ww/cw channel is ramping up..so it is not on full) Native optics..110-120 degree)
Disco effect is not nearly as pronounced ...

Ground cover is red granite/flourite/white quartz

Last edited by jeffkrol; 07-22-2014 at 08:30 AM. Reason: more
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Old 07-22-2014, 11:34 PM Thread Starter
Algae Grower

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Thanks jeffkrol for the link and the examples.

I've been looking around a lot today, and actually with typhon or similar controller, dimmable driver, lenses and cyan/red leds, it's going to be really expensive..

So, just tell me what would you do:

how many leds, and what color; what ratio (CW : WW : cyan/turquoise : 660nm red), I'm open to any suggestion.

The tank is about 60 gallons net; the leds/rows spacing and the distance from surface in the original project were not totally random, I tried to calculate the radius of the leds, without optics (so 120°), and that's what I've based my decision on to not waste too much light outside the tank.

Thanks again!

PS: hoping links are allowed, do you think that this tool is good?

http://www.1023world.net/diy/spectra/

Last edited by Amleen; 07-22-2014 at 11:47 PM. Reason: added info
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Old 07-23-2014, 12:41 AM
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Well there's more than one way to skin a cat. Another option is to go Bridgelux Vero/Luxeon CoB or Vero/Vero.

Straight from Digikey Italy
Vero 18 5600K x3
http://www.digikey.it/product-detail...198-ND/4747504

Vero 18 3000K Decor x3
http://www.digikey.it/product-detail...157-ND/3913132

Gets you this spectrum:

Take the orange decor line and combine with the blue line except the 90CRI 5600K pushes more green/cyan (per Bridgelux).

or another option

Vero 18 5600K x3
http://www.digikey.it/product-detail...198-ND/4747504

Luxeon CoB CrispWhite 3000K x3
http://www.digikey.it/product-search...-3090-1208CRSP

This combination gets you an even better spectrum:

Once again take the blue Vero line but has more green/cyan and the CoB.

Now you have a spectrum that those XM-L can't touch and quite a bit of power. Now you can switch to a Meanwell LDD-1000H and 48V power supply as you will never run those LED's past 500ma.

And here is the proof with my tank.

My lights are hanging 3ft high from the bottom of the tank with optics and I can push ~400PAR at full power. I added violet LEDs to my setup but if you go with Luxeon CoB you don't need it. Since you are not putting it high and you have a canopy no optics are required.
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Old 07-23-2014, 11:03 PM Thread Starter
Algae Grower

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These options are interesting.. I'm studying them!

I like the second option, with the Luxeon CoB CrispWhite; unfortunately, I've seen that there's not a version with a color temperature higher than 5600°K, but from your pics seems that you have a pretty natural light.. Have you tried it with some red plants?

Last edited by Amleen; 07-23-2014 at 11:22 PM. Reason: .
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Old 07-24-2014, 06:19 AM
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Check out Jacko's utube videos..

http://youtu.be/kHX1hosIgzE
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Old 07-24-2014, 10:57 AM
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Quote:
Originally Posted by Amleen View Post
These options are interesting.. I'm studying them!

I like the second option, with the Luxeon CoB CrispWhite; unfortunately, I've seen that there's not a version with a color temperature higher than 5600°K, but from your pics seems that you have a pretty natural light.. Have you tried it with some red plants?
I don't have any red plants but my Buce's are starting to turn interesting colors. As far as the 5600K you are correct and it's the highest you can get with a Vero. I prefer my light more in the 5000-6000K range. If you want a cooler looking light another option is to go with the original XM-L cool white but what you do is go with just 2 outer strips and then put the 3 CoB in between them.
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