High End COBs vs $2 COBs...

mefunky

mefunky

Well-Known Member
I've used several open Frame Chinese drivers for led reef lighting . I never had a fire or got shocked but most of them started making noise or died after a year or two . by the time I replaced them I could have bought meanwell and saved lots of time and a little money. Just my experience with open frame drivers good luck and happy growing
 
nfhiggs

nfhiggs

Well-Known Member
"I have used value priced drivers and have never had a safety issue. I find the lower price point a good way to expand my growing operation without sinking much needed capital into infrastructure."

That's pretty much what I have been saying.
 
muleface

muleface

Well-Known Member
you make an excellent point. Growing an environment with value priced drivers may be a good option.
 
G

griz78

Member
nfhiggs said:
LOL - Not really true at all. They ARE a major part of the cost - even at $12-$15 per cob. You're still assuming the use of premium Mean Well drivers at $0.25-$0.30 per watt, and $20-30 dollar passive pin heatsinks. While I'm using $3 CPU heatsinks, and budget power supplies that cost $0.07 per watt. You guys dunno how to "Ghetto DIY" this shit... LOL.

We are easily in the same efficiency ballpark as those Philips 13W bulbs. When you figure in the number of sockets you have to kludge together, those LED bulbs are not as nearly cheap as they first seem on a per watt basis. I can make 300W of COB light using a $25 power supply, six $2 COB's ($12), six CPU heat sinks at $3 each ($18) a $6 wallwart 12V supply to run the fans and $20 worth of wire and doodads. Roughly 80 bucks total. 300W of those 13W LED bulbs are going to run ~$120 just for the 24 bulbs you need - not to mention all the sockets and splitters. As for that "UL listing" and Warranty - that's out the window as soon as you rip the globe off the bulb to get that 120-130 L/W.

Don't get me wrong here- I think the LED bulbs are a good affordable option as well, but they are not really the cheapest...

There's more than one way to skin a cat, and more than one configuration for building COB's.
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I am looking at doing a budget cob setup. You seem to have experience in this area. Any particular chips, and heatsinks you would recommend? I already have a 36 volt 12 amp driver that I plan on using. Thanks
 
nfhiggs

nfhiggs

Well-Known Member
griz78 said:
I am looking at doing a budget cob setup. You seem to have experience in this area. Any particular chips, and heatsinks you would recommend? I already have a 36 volt 12 amp driver that I plan on using. Thanks
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Sounds like Cobbie has a good deal on some citi 1212's - If I had some spare funds available, I'd snap those up.

The ones I have purchased are these:
http://www.ebay.com/itm/272510858745
Run them at about 1 amp each.

If you want to do individual COB/Heatsink setups, get some CPU fan/heat sink assemblies from Ebay, like these:
http://www.ebay.com/itm/292113559111 The fans seem a bit fragile, but easily replaceable with any 90mm 12V fan. I run the fans with a 12V "wall wart" type 1 amp power supply.

If you want several on one sink, I would do the 4.850" heat sink from Heatsink USA and use one COB per 8 inches, with 120mm fans placed on top of each COB:
http://www.heatsinkusa.com/4-850/
 
CobKits

CobKits

Well-Known Member
seems to be a wave behind the cheap chips. ive been disappointed in the past but theyre always improving. if they are legit i will rep!
 
muleface

muleface

Well-Known Member
REALSTYLES said:
I've got too see how many I have to use to get the right spectrum @Moflow you sir are so might about that:weed:
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I would like to see some real leg work done on this topic. Thus far it seems like the cookie cutter model is, 3500k for stalk plants and 6500k for leafy greens. Also, 38 watts per sf for stalk plants. But this always took me as pretty general.

going back to the original question here, 38 watts on 2 different cobs produce different par values, so that number seems arbitrary. Color wise, growmau did some very elaborate light design (i can't find the video) it had cobs, uv blubs and red leds, not sure what else. I didn't see how they light produced as I think he gave it away. He always seems willing to take some risks for science, so its worth checking out his videos.

There was a really interesting setup in the lettuce grow challenge thread.... see randomhero8913

https://www.rollitup.org/t/all-cob-users-lettuce-grow-challenge.905662/page-48

he setup a number of different boxes with cobs ranging from 3000 - 6500 and grew lettuce under them. some of his pictures are gone for whatever reason, but it produced some interesting results.
 
RandomHero8913

RandomHero8913

Well-Known Member
muleface said:
I would like to see some real leg work done on this topic. Thus far it seems like the cookie cutter model is, 3500k for stalk plants and 6500k for leafy greens. Also, 38 watts per sf for stalk plants. But this always took me as pretty general.

going back to the original question here, 38 watts on 2 different cobs produce different par values, so that number seems arbitrary. Color wise, growmau did some very elaborate light design (i can't find the video) it had cobs, uv blubs and red leds, not sure what else. I didn't see how they light produced as I think he gave it away. He always seems willing to take some risks for science, so its worth checking out his videos.

There was a really interesting setup in the lettuce grow challenge thread.... see randomhero8913

https://www.rollitup.org/t/all-cob-users-lettuce-grow-challenge.905662/page-48

he setup a number of different boxes with cobs ranging from 3000 - 6500 and grew lettuce under them. some of his pictures are gone for whatever reason, but it produced some interesting results.
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I should have all of them on my SD card. I'll take a look tonight and upload them again.

2700k


3000k


3500k


4000k


5700k
 
muleface

muleface

Well-Known Member
what did you get from all of this, i know you had to shut it down to move. did you really see any difference in lights?
 
RandomHero8913

RandomHero8913

Well-Known Member
Nothing that we didn't already know. The 5700k plants we're much squatter, where as the 2700k started out pretty leggy. I did like the growth and structure from the plants under the 4000k lights. To keep busy I added 6 monos to the 4000k 105mm heatsink, an IR, some far/deep/photo reds. In the next couple of months I'll be able to properly grow again so we'll see how these lights do in tent with flowering plants.
 
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REALSTYLES

REALSTYLES

Well-Known Member
muleface said:
what did you get from all of this, i know you had to shut it down to move. did you really see any difference in lights?
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I can tell you that the 5700k rocks and I wish I had more CXA/2 Studio 95cri to play with my full spectrum cobs

1497036664845.jpg

I'll just use my 5000k DB CXB
 
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G

Goerilla

Member
I think I must share my experience with some Chinese cobs I have used.
I used them for chili and tomato seedlings but wondered why it seemed that the plants did nog grow very well.
The lamp had 2 different cobs a cool-white and a warm white, lumens about 15000.( I know but I don´t have the meter )
When I moved the chills to a window with a 15W cool white spot the growth really took off.
The tomatoes stayed and they grew very slow compared with what I´m used to.
My new cob though is a completely different story,under that the plants grow. ( Cititzen 1212 3500K Cri90

Rilla.
 
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