My Plan For A Cree Cxb3590 Light Bar

[tags420]

Right, each star drops about 10V @ 500mA. (The four internal diodes are connected in series.)

I was thinking about asking on the forums if the LED Engin stars were any good but these are new and improved so I'm in. ;)

I built a similar little light using 3070 4K's and cree 660's. I ran them all off an hlg700ma. It was a test build so I didn't put much into it. But a way I thought that might work to have red on/off control at least was to use a switch to bypass the reds straight to the next COB. And the other position would be running though the reds just like oyu have it in post #15. It would only allow on/off, but would be better than no control, and would give simple electronics and lower cost. I am just not sure if there would be a problem for the driver to run a switch like that while the sting is on.

I'll ask around some other places

 

[seaslug]

Thanks for posting, tags--I've been thinking the same thing. I was going to look for a small switch or jumper block that could be mounted on the bottom of the heatsink.

I keep drawing new plans, I ordered a pair of 2700K CXA3590 (77Vf) for a flower circuit--maybe I'll build one of these and another bar with eight 660nm stars on the 700mA and compare.

 

[Marxconha]

Hi Seaslug. I am from Brazil, and my english sucks! I am transalting the topic from SupraSPL "DIY LED with COB's - small medium and large grows. I will share in a portuguese forum, showing them how much late we are in this tecnology. Using only HPS and HQI we spend a lot of energy. The build with this lamp's(HPS & HQI) increase the cost of energy in R$150,00, something like US$ 50,00.

Searching for one alternative, i found the "DIY Full Spectrum LED's" in Aliex. But you guys said that is bunch of chineses crap LED's. So i find the Cree series, also in Aliex, and i order the CXA3590 5000k, plus x10 Cree XPE XP-E 3w RED and x10 Cree XPE XP-E 3w ROYAL BLUE. I pay US$ 88,00 (total) turning for Real (Brasileira) R$ 264,00.

I will have to buy the power supplies, the descripition of the CXA3590 says that is 117v. This mean that my power supplies need be over 117v? Guess this is a stupid question... But "I am not an electrician nor an engineer and this is my first LED fixture design" :)

About the efficiency, wroted from Supra, you, the cutie dog and tags420. Beacause of the my bad english i dont undestood what you guys said. This efficiency is compared to what? A HPS? So, considering on LED produced with 45% of efficienciy, the farming will be 55% less productive that one HPS?

And let me see if i understand what you say about the holder of CXA3590. You also dont have find this holder and you will put a Kapton tape holding in the heatsink?

Hope you (and other growers too) can help me, and sorry if you dont understand something i said. Most english i learned was playing online games like: Ultima Online and MU online. Thanks very much for your attention, or, like we say here in Minas Gerais, Muito Obrigado véi!

 

[Marxconha]

I forgot to say, i am not a big consumer. I am plating because i dont want to make part of the drug trafic. I hope with this LED i can illuminate the area of 1,5 ft² with 1 or 2 plants.

 

[seaslug]

SupraSPL mainly posts at a site I can't say (but you've probably been there) under Indoor Growing > LED and other Lighting. There is a thread he started, "DiY LEDs - How to Power Them". I don't know what 117V specification you are looking at; the latest Cree come in (nominal) 36VDC or 72VDC varieties.

A lot of people are happy using Kapton tape and thermal "grease" to stick the Cree COBs on the heatsink instead of using a holder.

This is the data for the Mean Well HLG-185H series. I added the Vf of the two COBs (144 total) and see the 1050mA model will be just right, 144V being in the middle of the constant current region of the supply (driver).

 

[seaslug]

Marxconha, I commend you on your effort to spread the knowledge. It takes time and effort to document something--even without a translation.

About the efficiency question--there is a difference from efficacy but to my simple technician mind they are about the same thing. I don't pretend to understand the physics behind all this but if someone says a COB is 45% efficient, 45% of the power (energy) going into the device is converted to photons and the remaining 55% is released as heat.

Edit: led_academy.pdf is a great introduction, I think. http://www.omslighting.com/data/images/ledacademy/pdf/led_academy.pdf

"Efficacy of LED luminaires
The efficacy (energy efficiency) of LED lighting fixtures is ratio between net lumen output (in lumens) and input power (in watts) of a luminaire, or lm/W. LEDs with the highest efficacy are the coolest whites – 5000 K and above."

 

[Marxconha]

Thanks seaslug!! Your information are very useful! I will read and them we talk about it!

 

[seaslug]

As an update, my plan now is the original design in this thread except using a lower wattage rated driver at near maximum with the two COBs. I think I'll add 100mm diameter glass lenses (with 80 degree angle). The flanges will overlap the edges of the heatsink but the screw pattern will fit. KingBrite (Jerry Meng) at alibaba has these: KB-HB100-80. I also ordered some 3000K CXB3590 from him--much cheaper than Mouser. Shipping (DHL) was $60 but I bought a dozen lenses (for six bars).

[A repost of mine from today:]
Unless we have a warehouse grow full of LED, I don't think PFC (power factor) matters to us. The power company gets cranky if their big customers have poor PFC equipment. PFC is not power supply efficiency although a good design will have good numbers for both. The Mean Well "A" models adjust down to 50%, where the 115 and 230VAC efficiency lines intersect.

I just changed my luminaire design to include a 230VAC fan and using HLG-120H-C1050 to power a pair of 3000K CBX3590 instead of the HLG-185H-C1050. PSU efficiency will be a bit better and both models use the same external case so I think cooling will be OK.

I bought parts for adding 660nm red but some people say 3000K has enough red so I'm going to build with just the COBs for now.

 

[seaslug]

A guy at RIU just built a six COB pentagonal luminaire using these lenses and the benefits outweigh the negatives, I'm hoping. I'm specifying medium speed fans instead of slow speed because I want to be sure enough heat is removed from the backside of the COBs. Opticgrowlights is selling premade COB luminaires with lenses.

 

[seaslug]

 

[REALSTYLES]

A guy at RIU just built a six COB pentagonal luminaire using these lenses and the benefits outweigh the negatives, I'm hoping. I'm specifying medium speed fans instead of slow speed because I want to be sure enough heat is removed from the backside of the COBs. Opticgrowlights is selling premade COB luminaires with lenses.
View attachment 511982

You should buy your CXB3590 from them as well. The guy from RIU got the kingbrite info from me and he also bought the cobs for $51 each to bin just mention Realstyles. I'm one of their best customers. I have already purchased 83 CXB3590's and some are 6500k DB and DD bin My last order was 51 that brings my total up to 159 3590's

 

[seaslug]

Yeah, I also bought eight CXB3590 3000K from Jerry. The package came quickly but had been sliced open by DHL security. The stuff was very tightly packed but everything seems OK.

 

[seaslug]

A companion deep and far red accessory bar:

 

[Marxconha]

Hello there! My CXA3590 and MeanWell driver had arrived (2 or 3 month wating... here in Brasil we say that Aliexpress is a gift from distant past). I still reading and writing, now i know more about led driver efficiency but have some questions. In a MW hlg 120h c1400 i can put how much CXA 3590? Just one?

 

[seaslug]

Marxconha, please post your part number; this one has a Vf of almost 80V @ 1400mA (Cree calls it a 72V):
CXA3590-0000-000R00AD30F (the R means 72Vf nominal)
You can drive one of these with the hlg 120h c1400 because the constant current region is 54V to 108V, or two (or three) COBs if you have the 36Vf type.

 

[Marxconha]

Hmm, now i understand! It's 72v (80v)! So i can put just one, in this case. But other question about electricity, i have bought some Cree XPE XP-E R3, the tension is 2,65v 3,6v but the ampère is 350mA-1A... so that mean that i can't put these to? Because i wanna run the 3590 in @1.4...

 

[seaslug]

I can't give a definitive answer without knowing your part number but this is what I see for Cree XP-E red:

So working with this spec, you would need to build a parallel circuit using three XP-E diodes (or multiples of three). This would make the current through each diode 1400mA / 3 = 467mA.

The voltage drop for each group of three XP-E would be about 2.2V. The Mean Well 120W (nominal) driver can power the 80V COB plus 28V.
28V / 2.2V = 12 groups of three parallel diodes.

In other words, you could run--in groups--between 3 and 36 XP-E diodes in series with a CXA3590.

Or with even more wiring, hook up the XP-E's in parallel groups of four which gives each diode a current of 350mA. I'd be more comfortable running them there, at half the maximum spec. (but I'm not familiar with the product).

 

[seaslug]

 

[Marxconha]

Thanks for the fast and demonstrative answer seaslug!! I study economy and don't understand nothing about physical :(.... Reading about parallel and series i understood what you said, you are f*** genius man! But, if i build a small panel with 10 XP-E R3 Red and 10 XP-E R3 Royal Blue, for one plant or two in max, it will work? The wavelength of Red is 620-630nm and the Royal Blue 465-485. I can put them on a medium square heatsink, glued with arctic silver and active cooling.

With this i hope save the CXA 3590 for one big project..
ps: about the heatsink, what do you think of building one? Here in Brasil the heatsink are very expensive and is impossible order one from EUA or CHINA. So i was thinking buying a big plate of cooper, do you have read anything about this?

If you came to Brazil one day i will be glad to show you the really Brasil!

 

[seaslug]

I don't see an R3 here?


Copper would be heavy and expensive. Aluminum "C" channel could work well enough but I wouldn't run a 72Vf COB at 1400mA on it without a high speed fan.

A dual band LED luminaire works fine, my Lumigrow lights are 470nm and 660nm. However, the 630nm is red-orange and plants will take longer to flower. You want a ratio of four reds to one blue diode, typically. More blue should be good for veg but I haven't tried vegging under LED.