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Building a Home Made LED

xmobotx

ecks moe baw teeks
ICMag Donor
Veteran
yeah ready to plug in like that is tempting but, being able to customize your spectrum more precisely wins out for me

somewhere i found a site where you could tailor your light and they came assembled

anyway; wondering about my choice of the "aqua" led {505n} ??? to me it seems like it hits the low spot typical to the whites ~idk if 480 might be better?

also, my 405 UV doesn't seem like toooo UV? more like "far blue" maybe ~not by appearance~ on that board {w/ 4 led} the UVs are 3.3v while the reds are 2.5v that circuit is getting 9v so,~2.25 ea ; the UVs are "dimmed" ~would anyone speculate that it is too much UV? {in ratio} say I made like 10 of those?
 

repuk

Altruistic Hazeist
Veteran
I finally got a killawatt like device to measure my HML, couldn't find the güvi hempfield mentioned (thanks mate!) but found this (german made):

Amps:

picture.php


Watts:
picture.php


This implies the drivers are rather efficient, measuring the DC volts/amps on the LED wires gave 58W DC for the 1050s and 53W DC for the 1750, so taking into account the device precision should be worse than my multimeter, efficiency of the drivers are great on 220-240VAC!

Also means my multimeter reads peak AC, I think it has two settings (peak and RMS) will look how to change the setings.
 

exploziv

pure dynamite
Administrator
Veteran
As this thread is a must read for anyone trying to make a DIY led panel, I've made it a Sticky!
Great work guys! Thanks everyone for contributing!
 

jcmjrt

Member
1030, I'm looking at building a fixture with XMLs as well and am wondering about putting on optics. You started without optics...are you completely happy with that choice or considering putting them on in the future? What have you looked at for choices for optics? I'm a little up in the air about it although I'm leaning towards at least starting with none as you have done as I don't think they'd be hard to add later.
 

medmaker420

The Aardvarks LED Grow Show
Veteran
This is a GREAT SPOT for this thread!

Can't wait to see how the convo goes in here because there are a ton of diy's currently in the works atm and 2013 is going to be the year of the led grow light (-:
 

tenthirty

Member
1030, I'm looking at building a fixture with XMLs as well and am wondering about putting on optics. You started without optics...are you completely happy with that choice or considering putting them on in the future? What have you looked at for choices for optics? I'm a little up in the air about it although I'm leaning towards at least starting with none as you have done as I don't think they'd be hard to add later.

IMHO optics are a wast.

Whenever a stream of photons hits a solid object there will be losses.
The standard Cree diodes have an effective spread of about 90 degrees. For me that is good.

What we are doing is growing shade adapted plants.
Short and bushy. This goes for the roots as well.
At this point, for me, the main problem is canopy coverage and equal light distribution.
Using lenses will create losses and limit coverage over and above what the base lenses will provide.

An XM-L will provide a 1 foot cone of light at appropriate distances
and produces enough lm/Par to be close to the sweet spot for intensity. (a quantum meter would be nice to have) Donations???

What I am using are lines of leds 2 inch spacing and each line is spaced 1 foot apart. This is working very well!

Being from an engineering background, I tend to want to max out the heat sink, but in reality, I could probably get away with substantially fewer leds and still get the same results.


And, THANK YOU for making this thread stick.
That is a great honor for all of us who have contributed here!!
 

jcmjrt

Member
1030, I'll go with your logic and leave off the optics. I've found myself designing for the max too...the driver can handle 16 XMLs and I'm headed off putting in 16 XMLs. :)

What do you think the appropriate distance is to get the 1 foot cone of light....about one foot or..??

Appreciate you sharing your hard work. :)
 

repuk

Altruistic Hazeist
Veteran
1030, I'll go with your logic and leave off the optics. I've found myself designing for the max too...the driver can handle 16 XMLs and I'm headed off putting in 16 XMLs. :)

What do you think the appropriate distance is to get the 1 foot cone of light....about one foot or..??

Appreciate you sharing your hard work. :)

Which driver is that?

Regarding distance, given those 90 degrees XM-L are good for, math it's easy: LED to canopy distance is half the surface you want to cover, so for 1 foot, height should be 1/2 foot...

Problem could be 1/2 foot for 10W LEDs could be too close... I'm using all white XM-L and haven't noticed any sign of bleaching, having the tops sometimes at less than 8". I suspect white LEDs are less prone to cause bleaching, while red, and specially blue are more...

So if you go for all-white XM-L design your luminaire to have complete coverage at 1 foot canopy distance. I solved that spreading them in two.
 

jcmjrt

Member
The driver is an inventronics 120W at 2100mA.
I was looking at all XM-Ls - Warm white to cool white 5:3 with them basically evenly spaced in two lines of 8 with each line on a 30" aluminum square 1 1/4" heat sink with a fan. I haven't ordered the drivers and LEDs yet. The driver is dimmable so if it's a little "hot" I should be able to dial it back. Eventually, I'm thinking that I might make smaller watt light bars that are deep red/far red and another for veg that's blue/royal blue to add in for flower/veg....but that's for another day....if ever.
 

tenthirty

Member
16 XM-L's on 30" X 1 1/4" square.
IMHO, maybe 80 watts max.
It's going to get hot quick, maybe 10 minutes or less.

I' running < 90 watts on a 36 X 1 1/2 finned anodized HS, and that is really close.
 

jcmjrt

Member
16 XM-L's on 30" X 1 1/4" square.
IMHO, maybe 80 watts max.
It's going to get hot quick, maybe 10 minutes or less.

I' running < 90 watts on a 36 X 1 1/2 finned anodized HS, and that is really close.

I understand the concern. It should end up less than 100 watts but that's a fair amount of heat to dissipate. I'm running it with a fan so that should make a big difference...and I could always add some "fins" if needed. I'll take it slow and careful when I'm bringing it up and keep a close eye on the temps.

...and that was 16 on two lengths of 30" square aluminum...i.e. 8 on each 30" length.
 

GP73LPC

Strain Collector/Seed Junkie/Landrace Accumulator/
Veteran
man gotta love these LEDS. im setting up an offgrid year round perpetual veggie grow off solar power with some LEDS. cant fuckin wait! free food year round... keep up the good work

would love to see a thread on this... :tiphat:

i have similar aspirations for the future...
 
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