[brestois]

Hi, i've been following related threads and researching over the internet for the last 2 weeks, and i've been really seduced by the idea of choosing led technology for my first growing room. I've been following knna threads here and in another forums, but most of his posts regarding choice of leds are already a little old , so of course , im sure i could have good results with that leds , but since development of led technology is very fast i think i could have significantly better results with new leds.
I will start with red ones:
I know that the 660nm wavelength is the better one for photosynthesis process, but i also know we were using leds in the 620-630 range since the little drop of the photosynthesis process is compensated for the better luminous efficacy in the 620-630 range. So first doubt: i see some new golden dragon at 660nm , should i choose this new ones or take the 625nm golden dragon or the 620-630 cree xp-e (i see cree released new xp-e leds with 73lm at 350mA, wich i like even if they are expensive but maybe it worth it)

My idea with this thread is to serve as a tutorial for people trying to make his own diy led growing ligth, so i will be posting all the steps i will follow, starting from choosing the leds, the assembling process and the growing process.

Well thanks in advance.

[rives]

I used the 660nm GD+'s, and have been very impressed with their performance. In my communications with knna, he had recommended roughly a 50/50 mix of 635 and 660. Since my fixture also utilizes PL-L lamps, which have a very good spectrum up through about 630nm, I used just the 660's to supplement with.

[brestois]

thanks rives, i was just reviewing your diy and then i saw your response you are really a model to me, your work is impressive!. So ok, i think i will follow that 50/50 rule for the red ones, i wanted to be sure, because i think the 660 gd+ are quite new, and before they were released we really haven't nice options for the 660nm so people preferred to go with 635nm, but now those gd+ seems to be the good option. Since you use PL-L lamps, you neither need blue nor white leds to complete the good spectrum for plants, but i need add some of them, i would like someone could advise me for that, right now I'm thinking of going with a proportion of 6 red:2 white:1 blue (or royal blue?) , 3 from the 6 red ones would be 660 gd+ as rives advises me.

EDIT: I see this led (data-sheet here) , with the "new technology" label in the mouser catalog. It is a osram one, also at 660nm but it is not a golden dragon, it is a oslon , available in 150º radiation or 80º radiation (wich one would be better?), that and the fact that it emits 332mW at 400mA are the only differences between oslon and dragon plus i could see , but the oslon ones are cheaper (dont know why). Someone worked with oslon leds so he could advise me?.

[alkalien]

The major difference for you between standard GD+ and Oslon are the soldering points. You can only use Oslons if you build PCB boards and are able to reflow solder. Then you should be able to get them for something like 1€, 1,2€ for the GD+. Blues are way more expensive.

50/50 on the reds seems to be the way to go.

[rives]

I'm glad that you got something out of my project, that's why I wrote it up! That Oslon package looks like it would be very difficult for a DIY application because of where the power leads are. The GD+ has leads that come out the sides with only the thermal pad under the package itself, where the Oslon had all of the connections located underneath. You might also check on the availability of MCPCB stars for it - I think that is the only way that you would have a prayer of connecting to it.

*edit* I see AA got here while I was typing.

[brestois]

Originally Posted by alkalien

The major difference for you between standard GD+ and Oslon are the soldering points. You can only use Oslons if you build PCB boards and are able to reflow solder. Then you should be able to get them for something like 1€, 1,2€ for the GD+. Blues are way more expensive.

50/50 on the reds seems to be the way to go.

I see...so no way to go with the oslons for me...i guess it must be difficult to solder it. So i think i will take the gd+, efficiency is a bit better on oslons (https://ledlight.osram-os.com/applica...ting-products/)
but gd+ seems easy to solder with that big pins on the sides.

Searching info about oslon led found this 9 minute video at the osram website, it shows the utility of gd+ and oslom in horticulture. It resumes all the important things we should look for in led in horticulture.
https://ledlight.osram-os.com/applica...-led-lighting/

Edit: thanks river, i just saw your response , and as alkalien was telling me, no choice for me, so i'll be picking the gd+

[grow_right]

i really enjoy my ds200 from advancedledlights.com

perfect size for a 2x2 area.

[brestois]

Originally Posted by grow_right

i really enjoy my ds200 from advancedledlights.com

perfect size for a 2x2 area.

if i could see wich leds it is using, maybe i wouldnt mind to pay a bit more for something ready to plug instead of building it by myself. If they were great ones like cree xp-e or osram gd+ im sure they would tell us, so following that logic, if they hide the brand of the leds, for sure they are not the better ones.

[setaemies]

Hi,

lately I've been researching the same leds, and been trying to wrap my head around calculating mW/uE per watt figures for those leds. Not much luck with that though, math hasn't really been my cup of tea ever

But considering that there isn't such a big difference in cost between 660nm GD+ (bin 1T - 3T) and Cree's XP-E red (bins P2 and P3) - I would go for the Crees, just because theres the possibility to choose the bin unlike with Osrams. Also I would prefer Crees for the narrower lens angle (GD+ 170deg vs 120deg for Cree).

Surely you have to add the cost of MCPCB and the extra work with Crees, but I think it will be worth it. I don't have any experience with reflow soldering, but you can find good tutorials and it doesn't look that hard.

I found this from another forum, and won't take any responsibility for the calculations. I think the comparison is between GD+ 660nm bin 2T and older Cree red bin N4. The efficiency calculation for cree sounds pretty high, considering that there are two more efficient bins today?

Cree XP-E red N4 62lm - fv 2.22V at 600mA. I calculated the radiant flux which is 540mW. So the efficiency is about 40%.

Cree XP-E red led of group N4 emits about 2.46 µmol of photons (the same as a GD+ 660nm with a radiant flux of 448mW at 500mA)

edit:

Found Knna's bulb analyzer tool and toyed around little:

https://www.2shared.com/photo/gaDCjYo...EredbinP3.html

https://www.2shared.com/photo/jY5FqP_...erred1T3T.html

edit2:

For blue leds, I stumbled upon Crees XT-E line. They seem very efficient, and good value for the money too. https://www.cree.com/products/pdf/XLampXT-E_ROY.pdf

[brestois]

Originally Posted by setaemies

Hi,

lately I've been researching the same leds, and been trying to wrap my head around calculating mW/uE per watt figures for those leds. Not much luck with that though, math hasn't really been my cup of tea ever

But considering that there isn't such a big difference in cost between 660nm GD+ (bin 1T - 3T) and Cree's XP-E red (bins P2 and P3) - I would go for the Crees, just because theres the possibility to choose the bin unlike with Osrams. Also I would prefer Crees for the narrower lens angle (GD+ 170deg vs 120deg for Cree).

Surely you have to add the cost of MCPCB and the extra work with Crees, but I think it will be worth it. I don't have any experience with reflow soldering, but you can find good tutorials and it doesn't look that hard.

I found this from another forum, and won't take any responsibility for the calculations. I think the comparison is between GD+ 660nm bin 2T and older Cree red bin N4. The efficiency calculation for cree sounds pretty high, considering that there are two more efficient bins today?



edit:

Found Knna's bulb analyzer tool and toyed around little:

https://www.2shared.com/photo/gaDCjYo...EredbinP3.html

https://www.2shared.com/photo/jY5FqP_...erred1T3T.html

edit2:

For blue leds, I stumbled upon Crees XT-E line. They seem very efficient, and good value for the money too. https://www.cree.com/products/pdf/XLampXT-E_ROY.pdf

I also like the narrower lens angle in xp-e but i do really see a difference in cost. how much would you pay for crees? i couldnt find them as cheaper as gd+. Plus you would need to add 1$+ for each led for the mcpcb. And then, efficiencies are similar, 540mw for xp-e at 600mA and 320mw for gd+ at 350 or 400 i cant remember. If i could buy crees at the same price than gd+, maybe i would take them.