1100K COB?

[Ganjagrowergu]

So I have plenty of light in my tent. It has been discussed previously that the only thing that I might need to add to my tent is some reds.

I have an old mars300 driver with heatsink and fan. I ordered a horticultural 1100k 50w COB chip and solderless chip holder today. Rated at 60V, 1.4amp max, and advertised as including 700-750nm far reds. My driver is 55-100v .7-.75amp...

I have been googling around a bit and I dont see people really using this Kelvin of light. Wondering if I just wasted $5.50 or not???

My current setup is a 32" x 48" x 60" tent with two qb288s in 4000k running at 240w. I also have a like new mars300 I will be hanging back up as I will soon be running a bunch of sativa landrace hybrids and they love extra light. Thought a deep red fixture might be a fun beginner DIY project.

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• Ganjagrowergu
• Dec 10, 2018

That's what the place looks like, messy but effective.

 

[TorturedSoul]

I accidentally pressed my space bar, so I had to cursor up to move your post back into view. I saw that upside-down baby and kind of flipped out for a second before I realized it was just a box, lol (I don't see all that well any more).

The lowest color temperature bulb I ever used (that I can remember) was a HPS one, 2100K, 2300K, something like that. I hope your COB makes it through the grow so we can see if it had any noticeable effect (either positive or negative, whichever the case may be). Things might get a little "stretchy" if something like that was to be used by itself, but as part of a greater light setup, it'll probably provide positive (if any) results. That's just a guess, of course.

 

[Ganjagrowergu]

All I need to do is hang her. 1100k cob being driven by a 2015 year model mars300 driver and cooled with the same mars300 12v fan. Math tells me that I should be pulling just about 50w from the wall. Bright AF.... had a hard time snapping the pics. Should be more than enough Reds for my tent now.

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• Ganjagrowergu
• Jan 24, 2019

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• Ganjagrowergu
• Jan 24, 2019

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• Ganjagrowergu
• Jan 24, 2019

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• Ganjagrowergu
• Jan 25, 2019

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• Ganjagrowergu
• Jan 25, 2019

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• Ganjagrowergu
• Jan 25, 2019

Thought I would finally give some kind of update. Autistic kids make projects hard to get to, but I managed to get this done just last night.

 

[fanleaf]

All I need to do is hang her. 1100k cob being driven by a 2015 year model mars300 driver and cooled with the same mars300 12v fan. Math tells me that I should be pulling just about 50w from the wall. Bright AF.... had a hard time snapping the pics. Should be more than enough Reds for my tent now.

20190124_220003.jpg

• Ganjagrowergu
• Jan 24, 2019

20190124_220045.jpg

• Ganjagrowergu
• Jan 24, 2019

20190124_220023.jpg

• Ganjagrowergu
• Jan 24, 2019

20190125_100121.jpg

• Ganjagrowergu
• Jan 25, 2019

20190125_100115.jpg

• Ganjagrowergu
• Jan 25, 2019

20190125_100114.jpg

• Ganjagrowergu
• Jan 25, 2019

Thought I would finally give some kind of update. Autistic kids make projects hard to get to, but I managed to get this done just last night.

You will actually only get about 39 watts out of it. The MARS drivers are rated as you say, (I have tested them) and you will not be at 60 volts on the COB because it will only use 60 volts at 1.4 amps. Since your driver maxes out at 0.75 amps your cob chip will be running in the 53-54 volt area. So if you take 53 X 0.75= 39.75 watts. With driver power loss and fan you will be pulling roughly 43 watts from the wall including the fan and driver power loss. Just thought you may want to know. I have also tested many of those Chinese COBS. the par levels even at 60W was dismal. If you lived cose enough I have about 7 different chips I would just give you. Neat project man but I hate to say, I have been down that exact road. After I had troubles growing seedlings from them I put my photon flux meter under them and was quite disapointed. You can see a ew of them I made in my 4 strain 6 auto grow shown down below in my signature if you would like.

 

[Ganjagrowergu]

Thank you for the math corrections. I am pretty new at this. I had actually come up with 44 watts (which was apparently wrong as well, lol) so I had rounded up and typed about 50 watts

I proved to myself that I could build a proper working cob fixture that doesn't burn my house down without breaking the bank, I can call it a win. I know about the lower bin diodes used in discount chips, that's why i chose not to go all in as well as the fact that I am already running 240w of qb288v1s and a like new mars300 in 10.6sq/ft. Definitely a fun project with tangible results.