DIY LED Question

Hey Guys/Galz

I´ll try to keep it short and simple

Would love to build a LED Panel one day, but Im no Electrician, Im a Stainless steel smith, so have some basic knowledge's and access to aluminum/steel and tools aso.

What I would like to do is build the most simple Panel, I don't care so much about $ per Watt or absolute best quality, or for that matter the cheapest solution, what I look for is a simple way to build a panel to cover about 3x4 ft and grow some dense Dank, not the cheapest way or the best or with the least watt used, more like with the least work for me, specially stuff like wiring and connect up different drivers and what els you need to make it shine

I know you need a heat sink and I bet I could come up with some thing for that, now one of my questions is that if I use a good/big enough heat sink (could just use it as the panel itself) would I then need to add fans ? (would love to avoid the more wiring and noise)

maybe if I get some quality LEDs and don't go higher then 3W and then run em with some quality drivers with out max em out (maybe run em a bit "low"/less then 2W/different mA ?) don't care if I need to add more LEDs to get the same strength if it mean I can run em with out fans and maybe even make em last longer ?

I would like to spread the LEDs out quite a bit any way as I would like to make it to cover all of my 3x4 ft room or close (need some room to work with) maybe use about 300W in a mix of white and red (I guess it would be 5000K and a mix of 630 and 660 or similar)

Now I know there are them multi chips and the cup reflectors (just saw some of you guys post em the other day) and I know I would have to add a lot of single 3W chips if I would like to cover my 3x4 ft with 300 true watt if I run em on less then 2W each, so I guess my second question would be what kind of LEDs would be the most easy to use ? agin I don't care so much if the kind is the most effective (I add a few more) or the cheapest (I only need to build one Panel) would less 5W or even 10W work ? or would they need a fan to keep em cool ? I saw them flood lights and they run up to 50W (maybe more) with out any fans ?

I guess thats it for now, Im sure I can come up with more questions as we go along

hiya Slipon, I've just ordered My 1st LED's for a D.I.Y. Panel build, next gotta get the Drivers. I'm subbed...be interesting to see how many "Helpful" answers or Info peeps Post.

Here's a Link to my Journal >

https://www.rollitup.org/blogs/706179-cc2012.html

and some of the LED Info & Videos I've managed to find, and will keep adding to this over next few weeks...

I'm more into PC Tech, but figure a lot of the wiring and such is just a case of research, research and more research...I don't mind this though(IF I become interested in a subject...I'm like a Dog with a Bone)

Peace

Thanks for the reply and the link, I´ll have a look at it

And yes I wonder as well, but I do know we have a few good Ppl. around here, and some of them are in to DIY LEDs so there is a few Ppl. I hope to here from and I hope at least one of em can read between the lines and see what Im looking for, I have very limited knowledge's when it come to electric, tho I can add more Ram to the PC or switch a contact at home aso (Im not a total fool) but Im more in to mechanics, ask my to take apart my Motor bike and we can talk, ask me how the electronic ignition on it works and I can't tell you much more then it got one

I need some "fool proof" add on parts, like Lego LEDs it more like a, add this chip, connect the two wires and switch it on, kinda DIY project Im looking for
if I need to use a few more $ and add/run a few more Watt to get the same as the best Cree quality LEDs with the best drivers build from the ground, I don't care as long as it works

For more of a plug and play type light I'd recommend emulating the panel gaius just built.
https://www.rollitup.org/do-yourself/805681-diy-led-grow-lights-cree.html

You could use bridglux vero 18/29 emitters to simplify wiring. They have a molex connector build into them and the connectors cost $2 with an 18" wire. Combine with a meanwell LPC driver per emitter and you practically have a plug and play DIY panel. Down the road you could add some monochrome emitters to balance out your spectrum and add a few extra photons.

Active cooling will allow your panel to reach optimum efficiency. More light for less power is always a good thing. If you don't want to deal with wiring for PC fans you could always use AC fans which (IMO) are a little easier to work with.

http://www.amazon.com/gp/product/B009P0R6VW/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A2AW0W4FKP16S5

thanks for the reply bicit

and yea I saw his CXA3070 thread the other day, look cool and similar to what I was thinking tho I would like some Red`s in the mix as well, maybe with a switch to turn em on for mid/late flowering ?

let me ask another question, what is the different between them Cree LEDs he use and then the flood light you can buy online in 5-10-20-30 and 50W ?

Slipon said:

thanks for the reply bicit

and yea I saw his CXA3070 thread the other day, look cool and similar to what I was thinking tho I would like some Red`s in the mix as well, maybe with a switch to turn em on for mid/late flowering ?

let me ask another question, what is the different between them Cree LEDs he use and then the flood light you can buy online in 5-10-20-30 and 50W ?

Click to expand...

Quality typically. You CAN use them, but they run hotter and put out less light than a DIY lamp with quality emitters. The learning curve isn't that bad, there are a lot of helpful members on this board who like to answer questions. Don't take the lazy way, projects like this are fun!

As far as adding some reds, it's a great idea. I'd check out this thread by supra for some insight on that subject.https://www.rollitup.org/led-other-lighting/754728-diy-led-cree-xpe-xte.html

Slipon, how's it hanging? Just recently I upgraded 2 of my BS240s by removing the diodes and screwing in 8 Illumitex F3s. I did no soldering since they use IDC connectors, just wire and bang done. Plus Illumis can be screw mounted directly on the heatsink, so no messing about with stars. Something tells me you wouldn't have too much trouble tapping heatsinks with your job description. You can get 25 F3s for 200 to 250 American. Look into Illumitex and + 1 for cobs too which can be mounted directly also. Hope that helps a little.

A nice simple light, Cree CXA3070s (3000K) on a large heatsink. I used 110cm²/watt and have no need for a fan. You could run them at 700mA 1050mA or 1400mA. The harder you run them the simpler the build will be to get the amount of light you need. If you are planning on a big grow I'd recommend bare 600HPS that is even simpler.

Supra -
Some elucidation please. As much for Slipon as myself. In Post #5 of your "How to Power" thread I got the impression that you were moving away from passive. But in Post #8 on this thread you say there's no need as long as the heatsink is big enough.

I'm trying to make sense of 110 square centimeters. I used google. 110 cm2 = roughly 17 sq. inches. I'm running a CXA3070 with one of those 700mA eBay drivers you recommended and it's pulling about 24W at the Kill-A-Watt meter. Some of that is driver loss but let's keep it simple. 17 X 24 = 408 sq. inches. I'd need a heatsink that was 20 inches W X 20 L to passively run one CXA3070?? Almost 2 feet on each side? Your pictures are showing heatsinks much smaller, and you've got two lights strapped on. I must be doing something wrong.

If I'm not getting it, then at least one other person has to be confused on this point also. I hope so anyway or I'm the dumbest one in class.

I also have questions about the third dimension. Your heatsinks have massive fins, which have to be more effective than really short fins. Do you have any thoughts on fin depth, and how that might affect the length X width recommendation?

What I'm trying to get at here is some relatively easy method for figuring out how much heatsink is enough to go passive with one CXA3070 at 700mA, 1050, or 1400. Maybe by the pound?

I'm sorry to be asking you to explain things 18 different ways...

Cripes, RIU wouldn't let me edit. I found simple height/width/length dimensions here. Post #6. I'm not getting the sq. cm. conversion right apparently. Is that enough metal for one CXA3070 passive, or two? And at any of the recommended driver currents?

thanks for the replies guys

FranJan@

its hanging well, cept for a small motor bike crash, a broken tooth a old knee that is acting up and Im running low on the herb`s

but I think this soon will help




and you know half of what you just wrote, you might as well have wrote it in Chinese, F3 Ilumitex BS240 ????

dunno ? any links or pictures ?


SupraSPL@

sounds good, I might also want to build a smaller one to start with, think it might be best to practice before I build a wall to wall light maybe some supplement lights for my 280W Bulldog light, I could see it work with a 3000K LED on each side to cover the side/end`s, so maybe build two small single lights and see how it go

what els beside the actually LED chip do I need ?

1x Cree CXA3070s

1x Driver to match (I dunno about the different mA to run em at, please explain)

1x heat sink (think I can get my boss to order a few meters home for me I´ll go for the one with the biggest fins for extra cooling

would I need a fan ? and what about power supply ? what do the list miss ?

Ooh yea and if I want to use a 600W HPS I have a old one in the basement from when I began to grow indoors, but don't want to pull that one up agin, the LEDs do a perfect job, with next to no heat


Mellodrama@

I think thats some very good questions, don't have a clue to half of what you asked, but Im sure its relevant

about the heat sink and the fins, yes the more surface the more cooling, also why they are made out of aluminum, as thats about the best material to lead heat (away)

and that is actually my first question, lets say I build the hole god damn panel out of one big heat sink, with big fins, and run the LEDs a little low, can I avoid to add fans then, so all I need is the LEDs, drivers and a power supply.


slip

This article may be of interest. It's for sound amplifiers, but many useful bits could be extrapolated to LED panels. I'll see if I can find a better example.

http://www.designworldonline.com/how-to-select-a-suitable-heat-sink/

Slip -

That's why I was askin'. Cause I figured that's about where you would be on the heatsinks.

I used Supra's suggestion for a 700mA driver. I bought four of them from the guy Supra recommended. Two have been used - running right now actually - and two are in waiting. The first two are driving two CXA3070 Z230F's. The ones Supra mentions in the first line of that thread. Those are warmer spectrum, more geared toward flower? I'm not really sure about that because some folks seem to think that's a good all-around light. It's definitely on the warmer side, let's just say that. They're bolted onto CPU coolers, which require fans. I'd prefer huge heatsinks and passive, but I'm using what I can scrounge.

I ordered two 5000K CXA3070's (Z450F) from Mouser a few days ago. Will pair those bluer CXA's (more of a veg spectrum) to the two remaining drivers. Figuring out the exact Cree product codes can be confusing, but the hodge-podge of numbers and letters tells you spectrum and bin once you figure it out. The Z450F is a lower bin 5000K COB but the higher bins simply weren't available the day that I bought. Higher bins give you more light for the same amount of power. If you'd like, you can go to Cree's CXA3070 data page. It's a .pdf called ds CXA3070.pdf. Find the Z230F and Z450F. They're both on Page 3. Once you understand the product codes you'll feel more confident about going to Mouser or Digi-Key and ordering.

Those 700mA drivers don't push the CXA3070's very hard. If I recall correctly, as long as the voltage is in the ballpark the CXA3070's will light up across a range from 300mA to 2850 mA. Or something like that.

LED's are more efficient when driven softly. When Gaius built his Battlestar he bought drivers that push the CXA's harder. That forces each CXA to put out more light, but with more heat and lowered efficiency.

To each his own. You can keep driving them harder and harder, but you gain less and less. 700mA is a nice safe amount.

With those drivers, you don't need a power supply. They accept AC grid power, and perform the DC conversion for you. The drivers Gaius chose also do the AC/DC conversion.

Going back to your last sentence, let's say you build the whole panel out of one big chunk of heatsink (lucky dawg) and run the LED's with those 700mA drivers, then yeah you're in business. No fans, no separate power supply. Just heat sink, COB's, AC/DC drivers, and thermal paste. I'd suggest the Ideal COB holders. I'm guessing you'd choose a drill press, a punch, the right drill & tap, and some screws over soldering onto your new COB's. I used #6-32 but I believe Ideal recommends M3's.

Please report back when you get the heat sink. I'm sure folks will be happy to give you some recommendations on spacing, how many, etc.

Good questions mello. I am moving away from passive in the flowering rooms but in this case Slipon specified simplicity in the plan. 110cm² refers to the total surface area that is exposed to ambient air. So you calculate the perimeter of the heatsink profile and then multiply that by the length. I use a spreadsheet to make it less tedious and to make quick cost comparisons.

The 110cm²/dissipation watt is based on LEDs that are about 40% efficient and for passive cooling only. If the LED is less efficient there will be more heat per dissipation watt. For active cooling I have found that I can easily double the dissipation wattage and if I crank up the fan speed maybe even triple it. 55cm²/Watt is a safe bet for quiet, effective and efficient active cooling. It gets more complex though, CPU heatsinks for example are optimized for active cooling so we can install more Watts with less surface area.

You are correct, the fin height affects canopy coverage and how concentrated your light will be. So tall fins are better for flowering and short fins are better for vegging. LEDs are getting so efficient now that tall fins like the ones I am using could allow us to over concentrate the light (more than twice the light of a 1000 HPS) and still maintain a decent junction temp. That means that as COBs improve my active cooled heatsinks will be overkill/an unnecessary cost.

You can see my flowering heatsink profile on the heatsink USA website (10.08" profile) and I already have many of the other profiles in my spreadsheet and happy to share that info (when google drive comes back online). It would be nice if they just gave us the perimeter for each profile. I use the 10.08" profile for flowering and the 8.4" profile for vegging.

In Post #9 of this thread I jokingly asked for a heatsink recommendation in pounds. Little did I know that Supra already provided the data in Post #159 of his DIY CXA3070 thread...

"Yessir 110 sq cm /W. That ends up being 6 pounds of aluminum for each 50W and almost as expensive as the LEDs."

Supra, I'm super glad you're doing all this analyzing and spreadsheeting because I'm more of the "close is good enough" type.

OK, so you're actually measuring all 3 dimensions. I didn't see a cubic expression, just square, so I missed what it was that you're doing.

SupraSPL said:

Good questions mello. I am moving away from passive in the flowering rooms but in this case Slipon specified simplicity in the plan. 110cm² refers to the total surface area that is exposed to ambient air. So you calculate the perimeter of the heatsink profile and then multiply that by the length. I use a spreadsheet to make it less tedious and to make quick cost comparisons.

The 110cm²/dissipation watt is based on LEDs that are about 40% efficient and for passive cooling only. If the LED is less efficient there will be more heat per dissipation watt. For active cooling I have found that I can easily double the dissipation wattage and if I crank up the fan speed maybe even triple it. 55cm²/Watt is a safe bet for quiet, effective and efficient active cooling. It gets more complex though, CPU heatsinks for example are optimized for active cooling so we can install more Watts with less surface area.

You are correct, the fin height affects canopy coverage and how concentrated your light will be. So tall fins are better for flowering and short fins are better for vegging. LEDs are getting so efficient now that tall fins like the ones I am using could allow us to over concentrate the light (more than twice the light of a 1000 HPS) and still maintain a decent junction temp. That means that as COBs improve my active cooled heatsinks will be overkill/an unnecessary cost.

You can see my flowering heatsink profile on the heatsink USA website (10.08" profile) and I already have many of the other profiles in my spreadsheet and happy to share that info (when google drive comes back online). It would be nice if they just gave us the perimeter for each profile. I use the 10.08" profile for flowering and the 8.4" profile for vegging.

Click to expand...

Any chance you have information for the 3.945 and the 4.600 profile heat sink from heatsinkusa by chance?

I hear ya mello, when it comes down to it I am a "close enough" type as well. I believe in the law of diminishing returns so I'd rather score an easy 95 on my test than bother to correct all my careless mistakes and work twice as hard to get a 100. Of course there are times where I give it my all and there is no room for shortcuts, like if I am wiring up electrical cable etc.

Google docs is back up, here is a comparison of heatsink profiles. The gray boxes are prefilled or auto generated. These are the numbers for a 1" length of each heatsink

Hey Slip sorry I didn't get back to ya sooner and even more sorry about the aches, pains and lack of ganj. But ya still can grow beauties !

Anyway a BS240 = a Blackstar 240UV model. No link needed .

Illumitex is a company that makes an excellent horticulture specific LED. Their naming convention is F1,F3,F7 for their different spectrums. Read about them here.
http://www.illumitex.com/illumitex-leds/
And here's a place where you can get 25 for $200.00
http://www.diamond-grow-lights.com/Illumitex-LEDs/Illumitex-Surexi-AD44-Horticulture-LED-F3-Flowering-Spectrum-with-IDC-Connector-25-pack::151.html

And here's a pic I posted in Supra's DIY sticky of my mod of my old Blackstar BS240. I think I'll always mix in some Illumitex LEDs in any panel I build. They also come in whites!


Hope it helps. Be Safe Slipon!

Fran...why did you go with Illumitex...quality...beam...value?

SupraSPL said:

Good questions mello. I am moving away from passive in the flowering rooms but in this case Slipon specified simplicity in the plan. 110cm² refers to the total surface area that is exposed to ambient air. So you calculate the perimeter of the heatsink profile and then multiply that by the length. I use a spreadsheet to make it less tedious and to make quick cost comparisons.

The 110cm²/dissipation watt is based on LEDs that are about 40% efficient and for passive cooling only. If the LED is less efficient there will be more heat per dissipation watt. For active cooling I have found that I can easily double the dissipation wattage and if I crank up the fan speed maybe even triple it. 55cm²/Watt is a safe bet for quiet, effective and efficient active cooling. It gets more complex though, CPU heatsinks for example are optimized for active cooling so we can install more Watts with less surface area.

You are correct, the fin height affects canopy coverage and how concentrated your light will be. So tall fins are better for flowering and short fins are better for vegging. LEDs are getting so efficient now that tall fins like the ones I am using could allow us to over concentrate the light (more than twice the light of a 1000 HPS) and still maintain a decent junction temp. That means that as COBs improve my active cooled heatsinks will be overkill/an unnecessary cost.

You can see my flowering heatsink profile on the heatsink USA website (10.08" profile) and I already have many of the other profiles in my spreadsheet and happy to share that info (when google drive comes back online). It would be nice if they just gave us the perimeter for each profile. I use the 10.08" profile for flowering and the 8.4" profile for vegging.

Click to expand...

I really hate ,'opposing ' you ...
(I 've great respect to you ..)

BUT I think tall fins are less efficient than short fins ...
Am I wrong ?


(..)
Fin efficiency

Fin efficiency is one of the parameters which makes a higher thermal conductivity material important. A fin of a heat sink may be considered to be a flat plate with heat flowing in one end and being dissipated into the surrounding fluid as it travels to the other.[9] As heat flows through the fin, the combination of the thermal resistance of the heat sink impeding the flow and the heat lost due to convection, the temperature of the fin and, therefore, the heat transfer to the fluid, will decrease from the base to the end of the fin. Fin efficiency is defined as the actual heat transferred by the fin, divided by the heat transfer were the fin to be isothermal (hypothetically the fin having infinite thermal conductivity). Equations 6 and 7 are applicable for straight fins.

\eta_f = \frac{\tanh(mL_c)}{mL_c}[10] (6)

mL_c = \sqrt{\frac{2h_f}{k t_f}}L_f[10] (7)

Where:

hf is the convection coefficient of the fin
Air: 10 to 100 W/(m2K)
Water: 500 to 10,000 W/(m2K)
k is the thermal conductivity of the fin material
Aluminium: 120 to 240 W/(m·K)
Lf is the fin height (m)
tf is the fin thickness (m)
Fin efficiency is increased by decreasing the fin aspect ratio (making them thicker or shorter),
or by using more conductive material (copper instead of aluminium, for example).

(...)
https://en.wikipedia.org/wiki/Heat_sink