Smaller DIY; Microgrower needs LED

smokey the cat

Well-Known Member
Hello LED Forum,

I've enjoyed learning the basics of LED lighting from you over the past few weeks. I've enjoyed reading through the many DIY threads and emitter discussion. I'd like to use this thread to give you an idea of my growing situation and see if you can help me make some intelligent choices regarding an LED upgrade.

My situation: I'm a guy who owns a multimeter and a soldering iron, and I feel confident enough that I'll make a decent enough hash of stringing some 20mm stars together. I'm looking to upgrade an existing micro grow that I've been running for about four or five years now - it's a small cabinet that I tuck into a bedroom closet. Currently this is split into two tiny chambers: one for vegging mum&clones, the other for flowering. I'm looking to turn the entire cabinet into an LED driven flower cab. Internal floor measurements are 570mm x 360mm, and the flower chamber is 790mm high.

Cabinet.PNG
View attachment 2867996

I'm comfortable with this cabinet even though it's showing it's age with numerous upgrades and gaffer-tape mods over the years - not exactly stealthy, but as it lives in a wardrobe this hardly matters. It's still available new, so I could potentially buy a fresh replacement if I wanted a new stealthy box compatible with my existing grow.

I'm also aware that it is a small cab - there isn't much vertical space in my box, but there is room in the wardrobe for something taller if I decide to upgrade down the line. I mention this as any LED board I build I'd like to make it future proof for a full height (1.5m+) grow space. Key point - I'm looking for good performance with buds quite close to lights. The box is <0.8m tall and we have to include space for the fixture and grow medium. At least with plants close to the lights they'll be getting plenty of lumens I suppose.

The need to manage the risk of light burn means that I think dimmable is the way to go, though I'm happy to hear any wisdom anyone might care to share on this matter.

The cabinet is equipped with twin exhaust 120mm computer fans on 12Vdc. In the past this ventilation coped with 240W of CFL tubes, and is now handling 96W of PLL along with the hot magnetic ballasts. I'm assuming that an LED fixture should be a piece of cake by comparison. In fact there is so much airflow at the top of the cabinet that I think a passive fixture might be possible if I find the right heatsink/emitter combo.

I've been thinking about mounting any fixture by simply from hanging chains from the ceiling of the cab, so I can position it to take best advantage of the exhaust fans. I'm not hung up on passive though - happy to go active, and it's unlikely any cooling fan will make any audible difference to the noise put out by the main exhaust fans.

Grow period - this cabinet is designed as a "flower" cabinet, but I'd also like to be finish off the last week or two of veg. So a flower(+veg) cabinet. This is potentially going to introduce a compromise here in terms of emitter spectrum, but let me tell you that compromise is all to common in the life of a micro grower! With two chambers in this tiny box at the moment I can tell you a lot about growing in adverse conditions!


Ok, so with all that in mind, lets talk power output and emitter choice.

Power output - I had been envisaging one solution as a single string of 30-50W of high end white Cree emitters on a single driver. It wasnt till I mocked up my cabinet MSpaint image that I realised that with over 2 square feet of floor space I "should" be using 80+W (2.2x40W/f).

Now, the beauty of DIY is that if I found my newly constructed 50W panel isn't cutting it I can upgrade with another string - such as a 30W red/far-red string to add during flower. And, lets not forget that "40W per square-foot" doesn't refer of the distance of the emitter from the plants - growing in a tight spot means I don't need penetration as no plant cell will be more than 600mm (or so) from the emitter.


Am I wrong to be considering 50W of Cree to be viable option? I was thinking of ten XP-G2 or a fewer number of XM-L2. Would I be better to add a second string of red/far-red in my intitial build, or keep it as a possible upgrade down the road if 50W performance was inadequate?


I'll post some more with ideas and questions about drivers, heatsinks and other information a newbie to LED technology might have. It's nice to contemplate a decent light which I can customise to my growing space. My 96W PLL lights have done OK, but I'm keen to take a next technological step and get more than 5-7" of light penetration.


Thanks for having me herebongsmilie - smokey the cat
 

lax123

Well-Known Member
And, lets not forget that "40W per square-foot" doesn't refer of the distance of the emitter from the plants - growing in a tight spot means I don't need penetration as no plant cell will be more than 600mm (or so) from the emitter.
vs
I build I'd like to make it future proof for a full height (1.5m+) grow space
maybe then you should consider getting lenses too, or maybe get some cheap cob from ebay for testing...there u get 5x 30W cobs for about 20$ in total...Combined with a dimmable Driver that might be something, full power and Penetration once you get the 1,5m
 

smokey the cat

Well-Known Member
=lax123;9745235]vs maybe then you should consider getting lenses too, or maybe get some cheap cob from ebay for testing...there u get 5x 30W cobs for about 20$ in total...Combined with a dimmable Driver that might be something, full power and Penetration once you get the 1,5m
Yeah, there are a lot of ways to skin this particular cat. I've been looking at those big cobs, but I think I'd rather stick to more known single emitters. There's just a bigger body of people using Cree 5W or 10W - and I'd really like some points of comparison for tweaking.

I am tempted by the thought of small adjustable cob in a new mom&clone box I'm going to build next.


Does anyone have an opinion on these drivers for sale on ebay at the moment? They are around $45USD
driver.JPG
To me it looks like a driver designed for a limited range of emitters - only supporting 30-36V. Street light or signage maybe.

Can I use this to run a string of XP-G2? The Cree data sheet and its forward voltage is 2.8V@350mA, up to 3.1V@1500mA.

Common sense tells me that 10 of them in series should be fine, though I've a nagging concern that the voltage of the emitters (10x2.8V=28V) will be lower than the minimum voltage output of the driver (30W). Or will the supply dump 30V in regardless, the chips run at it safely and everything will work out smoothly?

Presuming the cheap Chinese driver doesn't catch fire...
 

smokey the cat

Well-Known Member
Oh, and here's a picture of my current cabinet. This is Mandala Ganesh - I've been running this cut for years now. This pheno is low odour so no carbon, hardy plant that handles being tortured and burnt in my cramped little space.



DSC07979.jpg

Notice the slightly yellowing PLL tint to the photo. I don't even know the output color of these bulbs - fluro is such nice broad bandwidth that I've had luck flowering and vegging under any warm or cool light.
These four clones just were repotted a few days ago into 2l soil containers - they'll be switched into flower next week if they come along as I expect. I'd love to try hempy buckets or some other semi-hydro method of growing. But I'm lazy, I already have soil, and soil already works for me (mostly).

With an LED fixture I'll probably switch to 4l containers - my cab can squeeze 6 in. I'd use them now, but in a 45cm flower space I need the extra headroom that the small containers give me.
 

jimjim2609

Well-Known Member
Hey Smokey, here is cab, it is a little bigger than yours, it's 80cm x 45cm x 80cm. I am running 40w(10x)Cree XTE warm whites + 10w of deep red. So far the results are going good. The driver is a 40w driver running 1.2A and cost about $15 on eBay. It does run hot so I put it in a plastic project box with a small 70mm pc fan to cool it down and I've have no issues. I also run another 10w driver for the deep reds. The heat sink is 30cm x 14cm and also has a 70mm pc fan for cooling but if you have good circulation you may be alright without it. Here are a couple of pics and the big girl is freebie white widow x white shark. I only run 12/12 from seed. The Cree Xte cover most of what you need. You can buy a 50w Cree XTE board for $25 that way you don't have to worry about heaps of wiring and stuff. Cree leds are worth every cent.
 

Attachments

Abiqua

Well-Known Member
I have another option maybe.
I myself have 2 cfl indoor microgrows on tap. I keep saying that I am working on a winter DIY project [I yam] But out of my fuck up of research comes some knowledge maybe:
Especially if you are adding on later or even modular componentry of some type.....


Those 3,5 and 10w cree's are damn good choice even though I think I am going COB [dreaded cob!!!!!] Option:
Meanwell LDD Drivers and Meanwell 12v 4.2a Switching Supply
  • These little LDD's kick ass because they accept a good voltage range and are dimmable. So run a string of blues, reds, greens, whatever on separate drivers and then contort [dim] them to your mad desires!
  • The power supply can be mounted inside the cab or out, same with the drivers too. Doesn't matter both handle up to 95% RH

The LDD drivers are $7.33 apiece and come in 300,5,7,1000 ma versions. 2-52v Output. [1-16 3w's Cree's]
Full dimmable too, 0-100% [might be the best feature]
http://www.ledgroupbuy.com/ldd-drivers/

You could Wire up to: 4 LDD's in parallel to the power supply, which is $14
Meanwell rs-50-12
http://www.trcelectronics.com/View/Mean-Well/RS-50-12.shtml

The 8a version [8 1000ma LDD's] is $24
Rs-100-12
http://www.trcelectronics.com/View/Mean-Well/RS-100-12.shtml



Lumen output vs my setup
I don't know your datasheet specs, [for instance] 14 chips @ 3.0v [42v] @ 1000ma = 42 watts and lets say you can average 150lm/w = 6300lm per driver @ 42w's. That's quite a bit more than my pre-attempt @ half that.
Mine calculates to 3250 lumens @ 34 watts, so the chip efficiency I chose is undoubtedly lower than those Cree Xt's.

[I keep changing my mind but this might be the final one]
Light-bar

  • Start with 2 Bridgelux Vero 13's driven by 34.5v's @1 amp.
    • [These chip push 3250 lumens max at 34.5v's. [datasheet says 3600]
    • Power supply meanwell rs-50 and [2] LDD's @ 1000ma.
    • One 4000k and one 3000k Decor.
    • The drivers are dimmable so know I can dim in veg and flower if I want.
    • One 12" bar of 4.235" wide heatsink from Heatsinks USa and two 80mm fans.
  • Expand to 4 bars [8 lights] to cover a NEW! 2x2 cab, but I still have to find it on Craigslist!
  • Add in Dimmable 5000k for the 3,4,5k dimmable goodness.
  • Pray it works
 

Abiqua

Well-Known Member
Yeah, there are a lot of ways to skin this particular cat. I've been looking at those big cobs, but I think I'd rather stick to more known single emitters. There's just a bigger body of people using Cree 5W or 10W - and I'd really like some points of comparison for tweaking.

I am tempted by the thought of small adjustable cob in a new mom&clone box I'm going to build next.


Does anyone have an opinion on these drivers for sale on ebay at the moment? They are around $45USD
View attachment 2868214


To me it looks like a driver designed for a limited range of emitters - only supporting 30-36V. Street light or signage maybe.

Can I use this to run a string of XP-G2? The Cree data sheet and its forward voltage is 2.8V@350mA, up to 3.1V@1500mA.

Common sense tells me that 10 of them in series should be fine, though I've a nagging concern that the voltage of the emitters (10x2.8V=28V) will be lower than the minimum voltage output of the driver (30W). Or will the supply dump 30V in regardless, the chips run at it safely and everything will work out smoothly?

Presuming the cheap Chinese driver doesn't catch fire...

Dimmable Driver?

This Meanwell LPC 60-1750 is $21, same specs, little higher rated even 9-34v @ 1.750 Amps
http://www.trcelectronics.com/View/Mean-Well/LPC-60-1750.shtml
 

Abiqua

Well-Known Member
I have another option maybe. Those 3,5 and 10w cree's are damn good choice even though I think I am going COB [dreaded cob!!!!!] Option:
Meanwell LDD Drivers and Meanwell 12v 4.2a Switching Supply
Again, I may have run into a dead end. Just realized these particular LDD's are only PCB mountable. Shit.

On to octopart

Edit:
Yes, they do come with leads thank above [cheap in bulk too!]
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=2156287&productId=2156287&keyCode=WSF&CID=GOOG&gclid=CNPyvouMr7oCFaY1QgodNU0AFw
 

SnotBoogie

Well-Known Member
+1 for jimjim's suggestion, fully support warm white XTE + deepred combo for microgrows where distance to light is an issue.

With LEDs it tends to be the monochromatic blue LEDs that cause burning/bleaching, especially when combined with narrow angle lenses. This is presumably because short wavelengths are more energy laden than long reds etc.
 

smokey the cat

Well-Known Member
Hey Smokey, here is cab, it is a little bigger than yours, it's 80cm x 45cm x 80cm. I am running 40w(10x)Cree XTE warm whites + 10w of deep red. So far the results are going good.
Say that again - your plants look like mine, just dialed up six or seven sizes and with some decent led leaf lift. Is that a grow tent you're in?


I have another option maybe.
Meanwell LDD Drivers and Meanwell 12v 4.2a Switching Supply
Oh yeah - this is designing the cadillac fixture.
[I keep changing my mind but this might be the final one]
Light-bar

  • Start with 2 Bridgelux Vero 13's driven by 34.5v's @1 amp.
That Vero thread is mouthwatering - and it was the third result that showed up when I googled that emitter, lol.


+1 for jimjim's suggestion, fully support warm white XTE + deepred combo for microgrows where distance to light is an issue.

With LEDs it tends to be the monochromatic blue LEDs that cause burning/bleaching, especially when combined with narrow angle lenses. This is presumably because short wavelengths are more energy laden than long reds etc.
Awesome, this is the way forward for sure - warm white and red. I'm gutted to not be able to include more of the cool and nuetral colours, but to make up for it I think I'm gonna push the wattage higher.




Ok, here's where I am at.

I've been seduced by the look of the 50W Cree panels. You know the type?

XPG-50W____________boyatech_001.jpg

I'm thinking xp-g warm white - 50 watts putting out 4000-45000 lumens. Xp-g little bit more efficient than xt-e and the price is only cents different. Strapped to a quiet cpu cooler it'll be perfect. I presume that well rated sellers on ebay selling "cree" are selling actual genuine parts?

Point taken about Meanwell drivers above - I'd prefer decent stuff, but I'm at the end of a long shipping chain and its much cheaper to get generic chinese drivers. Hmmmm.bongsmilie It might be worth spending the money to avoid hotter generic units.


On the side of 50W cree I'd like to add something else - the next easiest thing I can find is a cheap and cheeky Chinese emitter like this one:
Power Consumption&#65306;30w
  • Power Input: DC:18-22V
  • Color Temperature: Red&#65288;Wavelength 620-630nm&#65289;
  • Color Rendering Index: 45-65Ra
  • Luminous Flux: 1200-1500lm
Crescent_LED_light_source_30W_Red_LED.jpg

Now this might be my lazy gene kicking in. This generic stuff isnt going to compare to 30w of quality red emitters with Cree or Osram on the label.

Has anyone seen a good 30W option around? Or am I looking at 20mm stars and more solder?


Thanks for the insightful posts, there's heaps to think about.
 

Abiqua

Well-Known Member
I say take a look at the Vero18's [Datasheet: http://www.bridgelux.com/assets/products_portfolio/Vero 18 Datasheet 04-16-13.pdf



They can be over driven safely to 2x nominal current and the Meanwell LPC-60-48-1750 would a be a great driver for each one. The driver won't do max, but that's fine, I bet you will put out as much as the Cree......and they are $18 bucks.

Not that Cree is bad, I looked at those initially too, but they aren't Cree you want. You can find them branded as Phillips too, which leads me to believe that they use cheap diodes too....

The cree's you should check out are CXA's

Digikey Search for CXA2011 / CXA 2520 / CXA 2540 / CXA 3070
http://www.digikey.com/product-search/en?s=28006&s=35421&s=35423&s=38367&FV=fff40008,fff80354,fffc005a&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
 

Bumping Spheda

Well-Known Member
The meanwell drivers will throw heat, too. I have a 60W meanwell driver that I can use as a heating pad for my bubble cloner. It still gets hot enough to warm 50fl oz of water a few degrees. A 100W meanwell might not be quite as lava-burning hot as a 100W Chinese generic, but I'm guessing it throws a comparable amount of heat and should still be considered "tent-warming."

I have an AC unit that pushes too much cold air into my tent. To combat this I made two vents on the AC's output that throws air into my room and closet to lower the pressure that's being fed to the tent. Over one of the vents I place the 100W driver so it now has either cooled or room temp air blowing on it at all times. Doesn't even get warm anymore, the Aluminum housing is quite nice in this scenario, good thermal conductivity. Kinda funny, though, it takes a while to cool the thing down after it's heated up. It's like the damn thing is solid Aluminum, it really wants to stay at whatever temp it's currently at. I'm guessing there's a huge transformer or something that's heat-sunk to the housing which helps resist temperature fluctuations.

The high CRI Vero 18's look nice, imo, too.
 

smokey the cat

Well-Known Member
Ok, I've spent the past few days pouring over data sheets and doing more and more reading. Brain ready to explode - arghh!

The Vero series looks like a hell of a chip: the problem I'm finding is they are a bit of a pig to drive. To complicate things I suspect I'd be better off with two flavours of white emitters to give a decent spectral coverage - I am thinking 2700 and 3500/4000.

The Vero 18 @ 30V is rated up to 2100ma, but has more headroom (over 3 amps? erk!). Data sheet - http://www.bridgelux.com/wp-content/uploads/2013/10/DS32-Vero-18-Datasheet-2013.07.18.pdf
Basically a 60+W part.
I'd love to run two of these, but the driver becomes more expensive, and I just can't see myself using all that light in my current micro grow.
The best suited driver for two of the Vero 18 looks like a Meanwell 150W unit - like the HLG-150H-30B http://www.meanwell.com/search/HLG-150H/default.htm - able to deliver 5A @ 30V to a parallel circuit with each Vero running at up to 2.5A.


The Vero 13 is listed at 32V - running at up to 1050ma. Basically the 18 cut in half - a 35+W part.
To run two of these in parallel I could use a 90W Meanwell LPF-90D-36 which outputs 21.6V-36V @ 2.5A, which should send 1.25A to each chip. http://www.meanwell.com/search/LPF-90D/default.htm
Driver is a lot cheaper obviously, and the Vero 13 seems a better fit for the space I have. Pretty tempting...


Am I right in that the dim-capable meanwell drivers can use a 100K pot to set output level? I won't need to use a PWM controller or a 10V supply if a simple passive pot will work in it's place.
 
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