Project New COB Veg Light, planning thread

[Ryante55]

Probably bare, Angelina type at most... The 1212 @500 mA is around 20-25w dissipated, I assume?

Ya that sounds right I'm not one of the smart guys here so my numbers aren't exact haha Check out the cheap an cheerful citizen thread. I would think some 120 degree lens would be good for a veg light if you want them close. Running bare is cool but personally I do alot of foliar spray during veg so it's nice to have the chips protected by a lens

 

[AtterStiga]

Ya that sounds right I'm not one of the smart guys here so my numbers aren't exact haha Check out the cheap an cheerful citizen thread. I would think some 120 degree lens would be good for a veg light if you want them close. Running bare is cool but personally I do alot of foliar spray during veg so it's nice to have the chips protected by a lens

Never been one to foliar spraying, what with bare bulb hps and all. What kind of lenses are cost effective though?

 

[coreywebster]

Probably bare, Angelina type at most... The 1212 @500 mA is around 20-25w dissipated, I assume?

The 1212 @500ma is about 52%-53% efficient and runs at 17watts ish giving 8 watts of heat

Check out the citi calc they have on site.
Check out the thread https://www.rollitup.org/t/diy-cob-led-calculator.890214/
for 2 calculators one for cobs in general and the other specifically for citizen chips.
The latest links are in bggrass signature

 

[coreywebster]

oh I have just seen Europe mentioned in your first post.
Primelight.co.uk are in England. They are a Citizen distributer with good prices. They also have just started selling or sourcing heat sinks by Mechatronix.
Here is an excerpt from the email I received
"Therefore a heatsink for the Citizen Type 5, I can offer you the MODULED 9950; MPQ is 27pcs however I may be able to support less than. Price is £7.95 each <54pcs"
This was for my clu058s so will be overkill for you running 1212s at 500ma but shiiit if you speak to Clare she will probably help you out. Shes been very helpful to me.
Here is another excerpt just because I thought it was funny...
"it’s by chance that this week I have quoted more prototype heatsink opportunities than I have in almost 5 years…"
I just laughed when I read that..
Heat sinks are not up on the website because they are redesigning the site.
Mechatronix are really good with their website, if you google a part number or go to their site they are clear as to what model does what dissipation ect.
Oh and I just checked my other emails, the 1212 is £9.76!
Usually minimum order is 20 but she will try and supply less but might cost more per chip.

 

[AtterStiga]

oh I have just seen Europe mentioned in your first post.
Primelight.co.uk are in England. They are a Citizen distributer with good prices. They also have just started selling or sourcing heat sinks by Mechatronix.
Here is an excerpt from the email I received
"Therefore a heatsink for the Citizen Type 5, I can offer you the MODULED 9950; MPQ is 27pcs however I may be able to support less than. Price is £7.95 each <54pcs"
This was for my clu058s so will be overkill for you running 1212s at 500ma but shiiit if you speak to Clare she will probably help you out. Shes been very helpful to me.
Here is another excerpt just because I thought it was funny...
"it’s by chance that this week I have quoted more prototype heatsink opportunities than I have in almost 5 years…"
I just laughed when I read that..
Heat sinks are not up on the website because they are redesigning the site.
Mechatronix are really good with their website, if you google a part number or go to their site they are clear as to what model does what dissipation ect.
Oh and I just checked my other emails, the 1212 is £9.76!
Usually minimum order is 20 but she will try and supply less but might cost more per chip.

Lol @ the rush for quotes. That sounds great, but I'm not in the UK so it's an open question if they'll ship to me. Definitely sending them a mail when I feel confident in my understanding. This is awesome information and this thread is developing into my project evolution log, and I'm learning heaps.

 

[AtterStiga]

Midway through the cheap and cheerful thread I'm wondering how much the higher Vf on the citizens will amount to in increased number of drivers.

Still not confident about the optimal light temps for a purely veg light. Best plants I ever grew spent three months in 16oz cups, two of those in like 6 to max 11°C, with just enough light to keep vegging. Coco, obviously lol. If I can reproduce the tightness and stem on those I'd just be tickled. As much blue as possible without doing harm?

Get the name of the cob holder with clips.

What number of 1212s is optimal per m2 @500 mA? 10ish (1ea ft2)? Edit: 1212 is 50%+ effective @500 mA, over 170L/W. Only data up to 4000K, not ideal for vegging I assume? 10 17w x 2.5(ish) par/w = 425umol/m2. Correct me if I'm wrong. DLI 27.54 @18/6.

Optimal distance from lights, how much headroom is necessary?

^notes for me, but please chime in. Beautiful thing when the mind grasps after knowledge.

 

[AtterStiga]

10 sounds so much more symmetrical than 11 at first. But 11 is actually kinda perfect. It would fit a 200w driver @500 mA (187w) and could give great coverage in a 4-3-4 bar combination. 470 umol, DLI over thirty. Of course, granting 1 m2 area. 3x4 would be 435 umol. Great size for some multitiers to save floor space. Distance to lights yet to be decided...

 

[AtterStiga]

Been advised on 12" distance, appr. 175 umol each @500 mA. How does this distance compute vs spread? At 6", following the inverse square law, it should be about 700each. If that is correct I foresee really poor spread. 11 1212s would deliver 7700umol, but I don't think this is correct at all... 10m2 @1100 umol? I call bs. Either the 175 number is incorrect or there is another limit to my understanding. I used LER pf/w of roughly 2.5ish multiplied by 187w, and arrived at 470. I do not, however, have a distance on that calculation, since I just stole it from RIU. Broken down; 17w x 2.5 =42.5. Pretty close to 470 for the rig. 170 = 4 x 42.5, so it seems that my calculations are@24". So if 470 @24" that equals 1880umol @12"? 1880x18x3600/1m= 121.8 DLI. Sounds crazy high, but will continue crunching numbers.

 

[AtterStiga]

Okay, so another lesson in how easy it is to screw up the little things. This time quite literally. First I ordered 50 M3.5 screws when I needed M4s. And now I just realized that it takes M3 6mm AND M3 10mm to attach the cobs and reflectors. I just got the 6mm. Good thing I caught it in time to source some locally. I put it here as a reminder of how easy it is to overlook the small but crucial things.

 

[AtterStiga]

Learned about wires today. The pretty cob holder for the 1212 allegedly only takes .5mm2 and the Ideal takes 75mm2. Tme.eu is our friends in this. They also have low to medium current drivers pretty cheap. Not to forget about the screws and such.

The 140 hs have 6mm deep M4 attachment holes.

 

[AtterStiga]

@G84 saved me yesterday by linking to tme.eu. have been there before, but then I was so lacking in knowledge it looked like Chinese to me. So now I'm filling up the cart with all I can think of. As of now:

.75mm2 solid core wire, 100m
M3/10mm, 100pcs
M4/6mm, 100pcs
M4/8mm, 100pcs
Grommets for keeping wires safe, 4mm inner diameter

That's where I'm at now, delivered to me for less than €50, and allegedly fast as well. Trying to think of other necessary things I can hitch onto this order, tips are always welcome.

Screws are apparently butter head, while Cutter ships pan heads. Not ordering before I got this sorted. The M4s don't matter cause they're for attaching the heatsinks. But the M3 are for the Angelina adapters. The Devil truly is in the details.