DIY LED with COBs - small medium and large grows

[HughJassBud]

@Purpletrain

what kind of lights are you running? How many? How far from the canopy?

I have 0 experience with DE's, which you mentioned somewhere previously, I think. In dirt, SOG was pretty ridiculous man hours, but I had to worry much less about supporting massive nugs and tying up long branches.....so I guess I thought it was a wash more or less. Either way, dirt simply became to much of a chore for me. This is why I'm remodeling sort of and restarting with hydro. A sog doesn't seem like a lot of work to me when its just changing a reservoir or topping it off every so often. However, maybe time will change my tune on this.

A scrog is basically impossible as I veg and bloom in different areas. Sure there are some mobile methods, but I don't want to mess with all of that.

I'm all about big wattage for stupid penetration and ginormous nugz. No doubt. I love that shit. However, it's certainly not the most efficient way to do things and can be hard to manage in hot climates like the south west where I live. I think COB's have their place now, but I don't think it will be growing trees YET. I say yet because I think the technology will get there eventually. Also, keep in mind that all though a single COB running at 50watts no doubt has less penetration than an HPS, you're running it 12" closer to the plant and spreading them out in such a way as to eliminate shadows and equally distribute the light. SO, maybe you can grow trees if you do it just so. I would love to see it, I would love to see the DE's against COBS just for "shits and giggles". For my part, I'll compare HID to COB using the SOG grow. Maybe someday in the future I will switch back to dirt and try some trees too. Hopefully you will beat me to it! Do I think the nugz will be as big and dense from COB's as a 1000w HPS? .......I honestly don't know, my gut tells me no but I want to be optimistic.

 

[HughJassBud]

Have you checked with Jerry at King Brite for those Cree COB'S? The CXB3590 was about the same cost for me recently as the cxa3070 from mouser. Maybe you've stated previously that it's not an option for you though.

If you're running 4 COB per driver, I would use the meanwell 185h style driver. That will be perfect for running 4 COB devices. Make sure you order the driver based on the voltage of COB you select. (72v and 36v variant) I ordered these from Jerry as well.

So, for the price you're showing there I would get the CXB3590 as opposed to the CXA3070. Just my 2 cents

 

[HughJassBud]

I'm having a little difficulty selecting the right cob to purchase - looking for a cxa3070's, or cxa3590's - Please assist me by telling my your opinions

this one?

same chip cheaper on digikey.com
http://www.digikey.ca/product-detai...0N00Z230F/CXA3070-0000-000N00Z230F-ND/4386666

This will be my first COB build - I'm looking to complete a 4 cob setup to begin with, to add in with rather then replacing my entire system at this moment.

and then to mount the COB's, witch would be more effective as there almost the same price, to do 4 artic alpines 11's? V.S. 2 pieces of heat-sink @5.88"x16"?

And then as to the driver would I be better off with 4 of -
or would I be better off with a 200 watt or 2@200watts or 25owatt Mean Well Driver?
I will be placing 2 of these on either side of one of those cheep inefficient "300watt 100x3watt galaxyhydro"
until I have the funds to entirely replace it
And how would I go about making them dimmable for vegging

Sorry, maybe I misunderstood. Are you running 4 cobs total or 8?
Is your goal to run them at 100% power or some fraction of that?
Are you vegging and blooming under the same fixture?

The drivers you choose will list a max amperage and voltage that can be supplied. The voltage is basically fixed by the COB you select. All things being equal, the cob should always draw the same voltage. Scaling the amperage up and down is what will effect your final wattage.
So if you want to run 2 cobs at 100% for example, you would require ~200 W, or:
(72v x 1.4 A) x 2 COB =201.6 watts.
OR it could be (36v x 2.8 A) x 2 COB = 201.6 watts

Pulling that kind of power will probably make for some high Temps though and reduce overall efficiency. That's why most of us are running half the amperage. As far as dimmable vs non dimmable, if you stick with meanwell drivers that's an easy adjustment either way. Me, I like the option of being able to dim even if I never use it LOL

Is this helpful?

 

[HughJassBud]

Lol, you responded when I was in writing I guess. I'll look up Jerry's info and post it here for you......just give me a bit to get home as I'm still driving.

I think the link shared by six string previously for a pin style heatsink is a pretty good one. You may be able to find cheaper. Heatsink design is a whole different ballgame. First, decide how you want to run these. Running at full power you'll need active cooling (a heatsink with a fan). Depending on your ambient temperature, you may be able to get away with passive cooling running the COB'S at 50% power using a pin style heatsink sink for example.

With heatsinks there are kind of 2 main parameters to consider. One is the overall mass of aluminum or copper or whatever the heatsink is made of and it's capacity to absorb heat. Another is the design of the fins/pins and how they move heat away. I am by no means an expert, but from my initial investigation it seems like you want about 140mm surface area on the bottom with greater than 7mm thickness and some pins that are 50-60mm in height on top of that. I should receive my order of heatsinks next week and I'll do some testing to see how they perform.

 

[HughJassBud]

I would need to look at the driver spec sheets to give you a perfect answer...but more or less yes, you can run half the COB'S at double the power. You just have to select the correct driver. Each driver is rated for max watts and max voltage. Voltage is additive in series, meaning if you use 4 cxb3590 @ 72v each they will pull a total of 288v all together in series. This can directly be multiplied by the maximum amperage of the driver to determine the maximum watts pulled. All of these have to fall within the parameters of the driver you select.

The meanwell drivers have several differwnt variants based on the max amperage they will provide. However, they don't scale to 0 amps. So, if my memory serves me well, a 1400mA driver can run between 700-1400ma. So if you're running 2-72v cobs that would be between 50% and 100% power. Or, you could run 4-36v cobs on the same driver between 25% and 50% power.....

I don't know if I'm doing a very good job explaining. Perhaps I should wait until I have a laptop in front of me.

 

[HughJassBud]

Jerry Meng

Sales Manager
----------------------------------------------------------

Shenzhen KingBrite Electronics Co., Ltd

Shenzhen KingBrite Optoelectronics Co., Ltd

HongKong KingBrite Technology Co., Ltd

Tel: 0086 755 29064293

Skype: kingbrite.jerry

Email: [email protected]
Website: www.kingbrite.cn

 

[HughJassBud]

no, your defiantly being quite helpful.

so would (@ 71-143 volt max)
http://www.jameco.com/1/1/52106-hlg-185h-c1400b-hlg-185h-200w-single-output-led-power-supply.html
Be able to run 2 cxb3590's @ 72 volt? x2=144volt

so is that driver no longer applicable? or would I use 2 "185h b modle" drivers @ 72v 700-1400ma - 50% to 100% (50 watts-100 watts a chip)

and this driver would not support a 36volt setup correct?
so Would?http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2148025_-1
or better suited
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2141667_-1

Yeah, I think that should still work. A lot of people are running 4-CXB3590's on the Meanwell HLG-185H-700x, it is rated at 286v max and 4 cobs @ 72v = 288v. Basically the same thing with people running 4 of the 36v models on the 1400x model. It is rated at 143v max and they would be using 144v.

 

[HughJassBud]

For heatsinks I would look at these if you run them at 50%......



It's as if they're reading this thread. They are now selling these for $0.50 less than what I bought them elsewhere for! Good deal I think.

If you plan on running them at 100% power, then I would get something like a PC heatsink for each one, something with a fan and probably a copper core.

That being said, this is advertised as being able to handle that kind of load passively, or almost at least.



Props @sixstring for showing me this distributor/manufacturer!

 

[sixstring]

http://www.jameco.com/Jameco/Products/ProdDS/2260607.pdf
or would it be better to consider these drivers?

depends on you and how hard you want to drive your cobs and what you want to cool them. maybe you should look at just buying one of these and be done with it

or this one maybe
they can be cheaper with a coupon code,email them and ask about it.super easy guy to talk to.
the timber kits are easy to build/set up

plc also sells all the stuff to diy yourself including a dif brand of drivers. but his new bar style fixture is only about 50 bucks over cost and the bar is waterproof so all the work is done and ready to plug in.
if you plan to diy your own light i would suggest doing some more reading and watch some videos so you can decide what type of power and cooling you want to use before ordering a bunch of stuff.

 

[sixstring]

200w and 12 bucks cheaper

 

[sixstring]

these heatsinks handle up to 80 w no fans https://northerngrowlights.com/products/sst140-heatsink?variant=20640814916

 

[HughJassBud]

Those are some really nice DIY kits. For not very much difference in cost you'll save a lot of effort trying to source all those components separately. Personally, if I weren't trying to buy things in bulk to make several of these at once, I would strongly consider the above options. By the time you factor in shipping on smaller orders of everything to piece together that kit, I bet you're in the same ball park anyway. Honestly, now I'm going to have to go crunch some numbers to see what the difference really is......

-HJB

 

[HughJassBud]

these heatsinks handle up to 80 w no fans https://northerngrowlights.com/products/sst140-heatsink?variant=20640814916

Also, FWIW, this is almost exactly the same thing I ordered from a different manufacturer. I ran COMSOL simulations on this design and think it's a winner. If your space/budget permits, this would be a good buy I think. Also, this COB technology and driver technology is only going to get better and less expensive.....there could be a day when you're not worried about burning one up so you just want to run them at near 100% all the time with newer, better drivers. That being said, I would buy the setup that allowed me to expand in that direction at some point in the future, otherwise you'll be buying heat sinks a second time later. Aluminum isn't getting less expensive. Just my $.02

@sixstring You've got all the cool links!

 

[sixstring]

Well guys,i haven't picked up anything from timber yet but i see how he handles biz with others and he seems legit.
As far as those other 2,plc and northern.i have prob read for close to 100 hours at a few dif forums and i chose those 2 guys to buy all my stuff from for 2 reasons.#1 they are both in the usa.#2 they are both easy to reach via email and or pm on the net.and they have almost no negative feedback.like was mentioned ,you may he able to source things a lil cheaper but once you factor in multiple shipping fees did you really save anything?

 

[sixstring]

you opinion on these @sixstring
but there 3500
I was thinking to build with 3000, not quite 2700 but its closer

or the 300Watt

My opinion based on lots of grows on various forums is 3500k cobs have a very good spectrum for both veg and flower.more balanced than hps or mh.i built my bars with 4x 3500k and 1 x 3000k cob per bar just to add a lil bit of red.i might try a bar with 2 x 3500 2 x 3000k and 1 x 2700k next but these bars i have now are kickin ass so far

Pics are easier to take under cobs also lol

 

[sixstring]

Those heat sinks wont handle 100w i dont think.aren't they 100mm? If so they are only good to about 60w without fans.like i said figure out how you plan to run your setup before you buy stuff.30 to 50w is the sweet spot for photons and efficiency. Im running my shit at about 36w per cob,lumen output at 36in below the lens is higher than a brand new 600hps at the same distance.

 

[HughJassBud]

[QUOTE="sixstring, post: 1725134, member: 30089" Im running my shit at about 36w per cob,lumen output at 36in below the lens is higher than a brand new 600hps at the same distance.[/QUOTE]

This is good info, I have been wondering about this. Also, WOW, I am a little surprised with those numbers. Clearly these are far brighter than I was anticipating even.

 

[jdb420]

I ordered 4 of the 250 watt kits from timbergrowlights.com. They are legit and I even talked to one of their main guys and he threw in a new silicone lens and also a difuser by ledil. They seem to be on the right track. I called to see if they would offer just the heat sinks. They don't have just heatsinks for sale, but would consider it after I talked to him about people wanting to upgrade to pin fin. So, I got more pin fin heatsinks ordered from northern today. The 30 to 50 watts model. So, I'll let you know my opinion of the timber kits very soon. Shipping took a week from order date, and overall the same parts I would source elsewhere for not much more in cost.

 

[sixstring]

what ma are you running the cobs at to atchive this

Im using 1050ma drivers now.but i do have some 1400ma drivers i will be using right next to the first set.so i should have a decent side by side comparison in a few months of the 1050 vs 1400 using all the same cobs and heat sinks.

 

[Spuzzum]

no, your defiantly being quite helpful.

so would (@ 71-143 volt max)
http://www.jameco.com/1/1/52106-hlg-185h-c1400b-hlg-185h-200w-single-output-led-power-supply.html
Be able to run 2 cxb3590's @ 72 volt? x2=144volt

so is that driver no longer applicable? or would I use 2 "185h b modle" drivers @ 72v 700-1400ma - 50% to 100% (50 watts-100 watts a chip)

and this driver would not support a 36volt setup correct?
so Would?http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2148025_-1
or better suited
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2141667_-1

If your string is 144 volts, then you really don't want to push a 143 volt supply. Rule of thumb for both safety and life of electrical products.. don't go over 80% of it's maximum load. Give yourself 20% headroom.. you'll have less problems overall. And less chance of a driver failing on you a year or 2 down the road. When you look at the life expectancy of the drivers, it's rated at 80% maximum load.

A better driver would be the 250W unit... 144 volt string / 179 volt driver = 80% load.

http://www.jameco.com/z/HLG-240H-C1...A-Single-Output-LED-Power-Supply_2260623.html

By the way... the 72v COBs use less current than the 36v COBs. If your using the 72v COBs, you probably want the 700mA drivers.. unless you're planning on running them harder than the 50w in this thread.

36v * 1400mA = 50w
72v * 700mA = 50w


Here's a 250w 700mA version driver that'll work.

http://www.jameco.com/z/HLG-240H-C7...A-Single-Output-LED-Power-Supply_2260607.html


Just make sure you match the current of the driver to the voltage of your COB. You'll fry the COB otherwise.