LED FAQ) Building and DIY

[Dion]

4x2?

ok so possibly run 4 cxbs one in each of the conrners on alpine type pc fan sinks? with the panel you have in the centre or if you wanna replace the whole lighting then if you wanna put 400w in there we can go with 8total= 1 per sq ft and run them at about 1.5 to get aprox 8000L/sq ft however prob overkill

u mentioned using the 10 inch profile do u want a single long bar? in that case perhaps consider running 5(or whatver u like depending on desired light) across the centre or are u thinking to stagger the spacing like not down the centre? or you could do a spyder bml type desigh? but whith 12 inch width that stagger thing will work well too and this makes sense now- i assume this was your plan?

i would run each cob off seprate drivers in this case so that you can turn some of them off in early stages( basically dimming)

hmm ill have to think about this but seems using the 10 inch with 5-6 stagered chips at 1.5 A (possible less) and 2 fans(consider 3 the cooler they run the better efficiency) would be pretty good

)using 6 chips) costs around $300 usd for chips and cheap drivers-but that sink- the sink is 130? wow
you can get pc coolers for about 10 each so half the price honestly though i am not too sure those heatsinks are the best choice- yes they will do the job i especially like thier thick base but the fins are not surated so the total surface area isnt all that much plus you pay for all that width-10 inches is .......25 cm? jesus christ mate

i would go for the 4.600" Serrated Fin( 8-10 inches long -the width of the cab) and do a bml spyder multy bar style perhaps 3 bars with 2 cobs and a fan each that woyuuld be 23ish per bar or 70ish total or pc coolers or 5 inch bits of the 4.600" Serrated Fin for each cob-you can prob get away with passive in that case

 

[neverforget4/20]

very interesting thanks for your thoughts.

i do plan on using the diy lamp exclusively and putting the current lamp to another use. I wanted to use the single 10"x 40" heatsink because i consider iy sort of an investment that can be repurposed and also because i have another grow space where 2 of these configuations would suit the space nicely. I planned on staggering the cobs along the length. It leaves plenty of room for fans and drivers.

Are you suggesting the 3070 chips @1.5mA? Do you feel that using a single driver per cob is the best bet?

Im fine with adding a third fan and driving the cobs @ at least 1.5mA. I like the idea of running the light at high intensity, without lenses, and adjusting the height for maximum effect. Since the space is essentially continuosly used for flowering id be keeping the lights fully utilized 12/12.

What k values are most efficacious with 3070's? The vero 29 is 4k and it seems to get an excellent response.

Do you have a link for a specific recommended driver?

 

[neverforget4/20]

the CXA3070 at 700mA is 25W and 42.6% efficient however the vero 29 at 2.1mA is about 40% efficient...is it worthwhile to employ a bunch more 3070s for that fraction of efficiency?

no editing privileges so added that question on...tyvm Dion

 

[Dion]

ah ok the heatsink makes sense now-cool then that takes a bit out of the equation good

i like a single driver per cob for the reasons stated in the intro- easy to swap out if needed/ lights can be moved up/down independently- with a single bar heatsink the 2nd option wont be available

i also like using 1 driver per cob because it is pretty cheap to get a driver that will run a cob(under 10 bucks) check the link in the electrical design section

42.6% efficient vs 40% efficient? where r u getting those numbers? at 700mA i woudl expect the cxa to be higher than that

from the info I have

LER For them is 3K(325lm) 4K(323lm) 5K(320lm)

so the 3000k will give you 48.8% at 700mA
at 1500mA its 40.9%
t 1400mA its 42%
this is AB bins ofcourse but ultimately we should look at lumen output to compare and l/w for easy comparason-i am not well versed in the veros so give me some numbers on those please( Lumens per watt as dif mA)
its easier to compare effeciency(in this brain anyway)
if i go chip A at 50w gives 8000 lumens
chip b at 50 w gives 7600 lumens so a is better
(amps is just a factor in the electrical desighn not where we wanna compare chips)

another huge factor is cooling

the higher the temp the less light output and the less efficiency

is it worth paying more for that extra efficiency? depends on lecky price really but i dont think those numbers are comparable

and ultimately how hard you drive cobs will determine the efficiency

 

[neverforget4/20]

Scroll down a lil bit and it shows values for the vero 29 latest version

http://www.alibaba.com/product-detail/Vero29-V2-Original-Bridgelux-cob-leds_60210986231.html

 

[Boyd Crowder]

been researching diy leds for months - dion's is the best tutorial so far in explaining drivers imho
in my research , ive found a supplier for crees at very affordable prices; 35% lower and better instock rates than mouser or digikey - kingbrite.cn

yes they are on alibaba , but the best method is to holla at jerry
the usa rep can be contacted at jl@kingbrite.cn
it still makes cents to use the 3070's because the good bin 3590s are very rare and command a premium , if you can get them from kb, they are still 20$ cheaper than digi/mouse but thats the thing , you aint getting em unless you are lucky. like dion said , you want 3590s? wait till cree's nextgen chips (12-18 months?) , then you might can find them.

 

[neverforget4/20]

boyd did you check out all tbat justified gear at auction?

What does your diy layout look like bud. lets see please.

i was just checking out vero29 v2s at kingbrite.

 

[Boyd Crowder]

boyd did you check out all tbat justified gear at auction?

What does your diy layout look like bud. lets see please.

i was just checking out vero29 v2s at kingbrite.

Missed that auction

i havent done a diy led yet - the $/w isnt there yet for me to justify it.
I have leds, but they just dont compare to hids $/w even counting with new bulbs every 4 months: for $200 i can get a brand new 1kw hid SYSTEM or a 450w led for $250 - theres no comparison imho - I love my led , but my next lights an hid ,

however, when those 3590s get to the 3070 levels in pricing and availability , ill build that 9-16up rig into one of my old vented reflectors , but only then - im not interested in bridgelux or epistars, just the crees have that allure for me

 

[neverforget4/20]

i dig your plan.

im new to growing. i started w a mars. worked well enough. those diy grows over on riu caught my attention.

So with Dions assistance im gonna get my diy on.

 

[Dion]

been researching diy leds for months - dion's is the best tutorial so far in explaining drivers imho
in my research , ive found a supplier for crees at very affordable prices; 35% lower and better instock rates than mouser or digikey - kingbrite.cn

yes they are on alibaba , but the best method is to holla at jerry
the usa rep can be contacted at jl@kingbrite.cn
it still makes cents to use the 3070's because the good bin 3590s are very rare and command a premium , if you can get them from kb, they are still 20$ cheaper than digi/mouse but thats the thing , you aint getting em unless you are lucky. like dion said , you want 3590s? wait till cree's nextgen chips (12-18 months?) , then you might can find them.

i appreciate your input however i do not recomend buying chips from other vendors as there is no way to know if the binning is as described or if it is an original

 

[Dion]

https://www.icmag.com/ic/showpost.php?p=6786583&postcount=486

bueno is doing great work with the veros here is a sheet from him

in fact he has a lot of data check his thread i recomend it to everyone

 

[Dion]

i dig your plan.

im new to growing. i started w a mars. worked well enough. those diy grows over on riu caught my attention.

So with Dions assistance im gonna get my diy on.

here is the biggest problem with using the 10inch heatsink seen as even canopy is a priority for your build

ofcourse these are not acurate diagrams but for consideration



here is a staggered version
black circles show dark spots in the corners while purple cyrcle show overlap/hotspots



here it is with more chips but evenly spread(as in the case of using veros or like lots more chips at lower current)

again dark circle shows lower light levels(relative though as it will still be nicely lit and even)

biggest issue is the overlap-purple circle/hotspot


here is what i suggest using the 4 inch heatsinks

even yum yum

so if you must use bars and even canopy is priority use more smaller ones

 

[neverforget4/20]

Dion,

thanks so much. Very useful comparisons of possible layouts. I didnt really have much sense of hot spots and dim spots.

i need to give more consideration to the light distribution.

 

[Dion]

Dion,

thanks so much. Very useful comparisons of possible layouts. I didnt really have much sense of hot spots and dim spots.

i need to give more consideration to the light distribution.

sure

just ditch the 10 inch heatsink idea-the only other way to get uniform canopy light would be to run the cobs in a stright line and have them higher but will loose a lot of light to the inverse square law or whatever its called

try 6 CXB3070s 3000k ab bin( as per link earlier), 2 per rail on 3(http://www.heatsinkusa.com/4-600-serrated-fin/) 16ish inch rails horozontally @ 1500mA (drivers as per link in electrical desighn) for aprox 5800L per sq foot evenly spread and also you will be able to move it/ make this project again for your next space

cost 300 bucks for chips and drivers 108 for sinks

edit: or you can run them at a lower current like 1.3 etc for effeiciency if you like
or you can use the pc style sinks one per cob and then you wil be able to move them up and down and all around however you like

or you can use a lot more vero cobs ( 29s or 18s) like bueno does although after just looking on digikey i dont get why peeps use them 28 bucks for 9000L less effcient than cree?
i must be missing smth

 

[neverforget4/20]

Yo D, thanks for the pm link. i cant reply with a pm because of low post count.

i couldnt find any details on the output of that product. in the comment section there is a mention of inadequate flower power. A plug n play solution would be cool but electronic diy is brand new to me and i am learning everyday. i really enjoy that. Utilizing the learning is something im seriously looking forward to.

Vero29 lamp represents and even better value than the Vero18. The "200W" version is actually dissipating about 160W and the 4000K should be about 39% efficient which is really impressive for a commercial lamp. The only other lamp that might come close is the newest Apache tech which claim to be using the top bin Nichia 119Bs.

i dont have the experience or understanding to talk about the vero cobs. If you browse around the diy threads at riu there are several vero advocates.

Supra : "Vero29 lamp represents and even better value than the Vero18. The "200W" version is actually dissipating about 160W and the 4000K should be about 39% efficient which is really impressive for a commercial lamp. The only other lamp that might come close is the newest Apache tech which claim to be using the top bin Nichia 119Bs."

 

[neverforget4/20]

D, is there any kind of simulator to model those light cones as shown in your post up above?
How did you approximate the patterns you show.

many thanks
Bro

 

[Dion]

dunno about simulator i just used common sense they r light sources-if it were any other type of lighting where woudl u hang your bulbs?
they r not accurate or to scale but just for consideration

the cobs put out light at 115 degrees from an aprox 2cm surface

 

[blynx]

Excellent FAQ Dion! Thanks for writing it. Very useful information all in one place.

I'm more inclined to lean toward more lower power lights than one single powerful light in a small area.

Would a 3070 be too much for a 1'x2' area or would it be better to use multiple lower power LEDs in a smaller area?

 

[Dion]

Excellent FAQ Dion! Thanks for writing it. Very useful information all in one place.

I'm more inclined to lean toward more lower power lights than one single powerful light in a small area.

Would a 3070 be too much for a 1'x2' area or would it be better to use multiple lower power LEDs in a smaller area?

great question blynx

i think this may be smth alot of ppl think about so here is a long answer

a 3070( or any model or any wattage led chip-ie a 700w chip) doesnt actually give any info- its the current that you drive the chip at that matters

thats why for simplicity i prefer to compare LED chips by watts and lumens

so the 3070 could be a 20w chip or a 50 watt chip or even a 116.5w chip

the softer you drive it the more efficient it will be but the less light it will produce




here you can see the info- i put lumens per dollar on the rightest side

so 1 3070 will not be too much for that space neither would 2 or more but 1 per sq foot is a happy medium imo- even light spread and you can drive them soft enough for good effeciency
a better(or easier for this brain anyway) way to aproach the chip choice question would be to ask:

how many lumens do i need?
then work backwards to find the cheapest/most electrically effiecient/ whatever you priority for your grow is(in the case of minimal heat electrical efficiency will be a target) to get there

so short answer:
"Would a 3070 be too much for a 1'x2' area or would it be better to use multiple lower power LEDs in a smaller area?"

no infact you could run that chip at about 2.6A and get 11000L but you would be getting only 104.6 L/W and consuming 106.7w total
you would not have an even spread of light across the canopy though (279 L per $)

SO

i would run 2 chips in that space at about 1.2A and get 12500L achieving 141.8 L/W for a total of 88.2 watts ( 156.4 L per $)

see how that works?


anyway more higher power lights run at lower power is better if budget allows

 

[grouchy]

Blynx, I would go with two. I am running a 9"x18" footprint with two running at 60 watts each. I am using a dimmable driver so I can add more power or take it away depending on heat and height restrictions I may run into. A couple 3000k 3070s is what everyone in the micro section needs imo. It fixed a lot of my problems I had.

If you are putting them in a cab I also recommend mounting the heatsink through the cab ceiling and letting the heat vent outside where you won't have to scrub it. I have two arctic 11 pc coolers mounted through a piece of 1/4 aluminum for the roof of my cab. It is removable and also houses a couple far red leds for putting them to sleep every night.