Cree CXA3050 100W Custom LED Grow Journal with Dinafem Blue Widow

This is the initial build that I found:

https://www.circuitsathome.com/diy-2/high-power-led-grow-light-a-build-log

Then I ended up here, same concept though, using CPU heat sinks.

The biggest thing I have yet to fully flesh out is how to handle splitting up the power to run it to the pucks, I am sure it is very simple, but it is one thing to know how something works in theory, and another to actually build it.

I am also leaning towards using mounting hardware like this:

http://www.mouser.com/ProductDetail/TE-Connectivity/5-2154874-3/?qs=/ha2pyFaduhDwX9GWCL8Qifh51DgPxlhL6cKryZ14oJQyMiphWmp0A==

http://m.youtube.com/watch?v=fSPnDY557AA&desktop_uri=/watch?v=fSPnDY557AA

This video is how I plan on doing mine at about the new year when im done and might have a few extra buck to attempt a cxa3590 or a xca3070/3050 build. Also assuming that those drivers come out then. After more resesrch philps may be promising followedby SL Power n Amperor

One thing I have been wondering, but have yet to find a definitive answer about is, do you actually need pucks when running from a high power power supply. For example, let's say I have a cv/cc power supply, and it outputs 48v and 5 Amps. The cree cxa3050 runs in a range from 1-2.4 amps, would it be possible to just connect 5x3050s in parallel. In theory wouldn't it just output 1 amp to each 3050 and negate the need for pucks? If the power output varied it would only change the brightness of the leds... And even if one 3050 blew it would still be well below the 2.4 amp max current. I feel like this is not possible for some reason that I am missing because otherwise people would already be doing it, seeing as it would save a lot of Money on the build...

looking at the Datasheet page 7 2nd Diagramm, i guess they wont light up at all or very dimmly, because of the low voltage 48V/5 -> imagine the current in that Diagramm @ 10V...but i would not bet on that im right lol

Well thenyou would just need a better V, I was also wonderinb the same thing. Since most drivers that I have fou d tend to lesn towards a higher constant Amp. Ive got to ask what are pucks, havent came across tjose in my research so far.

My understanding that running in parallel voltage stayed constant and that amps were distributive.

the 3050 are by far the best choice after researching on the cree site and playing with there programs that calculate output and efficiency. The 3050s are up at 150-160 lumens/watt in the 1 - 1.4 amp range at 34-36vdc. They are by far the most efficient besides the 3590.

pucks are just board based dc to dc converters. They insure that your LED won't experience thermal runaway. My understanding is that as the LEDs heat up the Vf increases and they draw more power and heat up more and then burn them selves out if they can just pull more and more voltage. The puck basically acts as a distributor, capping the power draw, if your are running from a power supply that has the ability output more then the LEDs can handle.

My understanding that running in parallel voltage stayed constant and that amps were distributive.

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ops, so is mine, was thinking series sry. I think it should work, as Long as its still safe if one led Fails as u mentioned. The Problem with parallel is the difference in each led compared to the others, so flow will not be distributed equally which gets worse as they heat up (thermal runaway), but as Long as the cooling is good...

I would think that if all the LEDs are the same model from the same batch that the differences in them would be try minor, none significant.

How LEDs become overdriven
Even if the LEDs are all from the same production batch and sequentially manufactured, the Vf of individual LEDs still has a ±20% tolerance. The tolerances mean that the total forward voltage for each string can be very different and therefore the current mismatch significant (see Fig. 2). In a test using identical SMD LEDs from a single production batch and using 1 Ohm resistors to help balance out the forward voltages, the currents flowing in each string were measured to be 306mA and 394mA. The LED driver was still doing its job of correctly limiting the current to 700mA, but the over‐current flowing through the second string was seriously overdriving the LEDs.
Worse, as the LEDs started to get warm, the combined forward voltage of the higher current string started to decrease. This increased the imbalance and more current started to flow through the already over‐driven string. The current through the other string of LEDs reduced as the constant current driver compensated, so they started to cool down and their forward voltage increased. The net result was thermal runaway with the majority of current flowing through one string only, even though the LEDs were mounted on a large metal heat sink. The test was stopped when the current imbalance was 600mA to 100mA. Obviously, if this situation was allowed to continue, the over‐driven string would eventually fail and then the entire 700mA would flow through the remaining intact string and destroy that as well. http://ledsmagazine.com/features/6/2/2

Quick update. Sorry the picture isn't as clear as usual. I'll try some different settings.

Here she is at day 26. The lower leaves are dying off and I think I need to give this little whore a couple doses of nitrogen. I don't want her leaves dying off too soon.

bbspills are you pumping 50w or 100w into each chip?

Wow..those cree cobs are doing amazingly well. Leds are getting easier and easier to implement. I don't think it'll be long before panels with high led counts are outdated.

I wonder what's better? 4 25w cobs or 1 100w cob?

I'm thinking smaller ones spread around would be quite nice. Whatever the area to cover, simply divide the watts you want to consume into smaller seperate sources.

bondoman said:

bbspills are you pumping 50w or 100w into each chip?

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50W into each LED. Both have their own driver

Positivity said:

Wow..those cree cobs are doing amazingly well. Leds are getting easier and easier to implement. I don't think it'll be long before panels with high led counts are outdated.

I wonder what's better? 4 25w cobs or 1 100w cob?

I'm thinking smaller ones spread around would be quite nice. Whatever the area to cover, simply divide the watts you want to consume into smaller seperate sources.

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I think more spread out would be better than just 1 single source. You would get much better coverage and could get the light closer to make up for the penetration

bbspills said:

50W into each LED. Both have their own driver

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ok that's what I thought, thanks

I have studied the numbers and the 2530's have the best lumens per watt better then the 3050 look at the numbers. if you run them in parallel then you need pucks . I use 700ma mean well pucks because the lower amps actually increases the efficiency. To wire the pucks you just wire solder a puck to each led and then twist all the positive wires together and negative wires together and then hook it up to the power supply the mean well 320 watt supply is 95% efficient.

samitch26 said:

I have studied the numbers and the 2530's have the best lumens per watt better then the 3050 look at the numbers. if you run them in parallel then you need pucks . I use 700ma mean well pucks because the lower amps actually increases the efficiency. To wire the pucks you just wire solder a puck to each led and then twist all the positive wires together and negative wires together and then hook it up to the power supply the mean well 320 watt supply is 95% efficient.

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Am I missing something? What do you mean by "puck" you mean DC-DC constant current drivers? This is not running them in parallel, you are just creating parallel circuits from one source.

http://www.ebay.com/itm/New-DC-DC-600W-10A-Digital-controlled-Programmable-Step-down-Power-Supply-Module-/121111330412?pt=LH_DefaultDomain_0&hash=item1c32cc3e6c

I want to get one of these and play around with it...

I tried the mounting hardware and wasn't too impressed the best materials for your money that I've found is mg thermally conductive epoxy and some fat aluminum then you don't have to screw with fans and its completely silent

Yeah I mean constant current drivers they have them cheap at powergate llc

the mean well 320 watt supply is 95% efficient

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AC-DC 0,95, DC-DC 0,95 0,95x0,95= 0,9025 Efficiency...nothing too Special anymore