Is 30" tall enough for COBS? If so please advise on my build.

1

1212ham

Well-Known Member
It will work ok. The current adjustment range for your driver is 3.9-7.8 amps, or 433 to 866mA per strip.
 
V

Vehlor

Member
1212ham said:
It will work ok. The current adjustment range for your driver is 3.9-7.8 amps, or 433 to 866mA per strip.
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I thought that since it is a CV driver, all I could do is adjust the voltage and then the led would pull what ever current is associated to that voltage. For example if I adjust the voltage to 22.1v, then the led would only pull 700ma, if I adjust the voltage to 22.7v, then the led will pull 1000ma.

So, what you are telling me is that if I connect 9 strips to that driver and adjust the current ouput down to 4.5 amps, each strip is going to pull 500ma at 22.1v, even though 22.1v is associated to 700ma? Isn't this going to damage the led?
 
ANC

ANC

Well-Known Member
Just stick with it. It is important to match the driver and COBS. If they can't use 100% of the output, the dimming function becomes much less linear.
 
1

1212ham

Well-Known Member
Vehlor said:
I thought that since it is a CV driver, all I could do is adjust the voltage and then the led would pull what ever current is associated to that voltage. For example if I adjust the voltage to 22.1v, then the led would only pull 700ma, if I adjust the voltage to 22.7v, then the led will pull 1000ma.

So, what you are telling me is that if I connect 9 strips to that driver and adjust the current ouput down to 4.5 amps, each strip is going to pull 500ma at 22.1v, even though 22.1v is associated to 700ma? Isn't this going to damage the led?
Click to expand...
Keep in mind, those adjustments are limiters. Turn down the current limit and the voltage will drop a bit, turn down voltage limit and current will drop. Study the voltage vs current graph in datasheets. Don't worry, turning down the voltage or current limit can't damage the LEDs.

A poor analogy, volts = water pressure and amps = flow rate or gallons per minute. Turn down the pressure and there will be less flow.

Some good comments from cobkits, he probably explains it better.
http://rollitup.org/t/introducing-cobkits-com-specializing-in-diy-and-citizen-cobs.916763/page-162
 
Last edited:
V

Vehlor

Member
1212ham said:
Keep in mind, those adjustments are limiters. Turn down the current limit and the voltage will drop a bit, turn down voltage limit and current will drop. Study the voltage vs current graph in datasheets. Don't worry, turning down the voltage or current limit can't damage the LEDs.

A poor analogy, volts = water pressure and amps = flow rate or gallons per minute. Turn down the pressure and there will be less flow.

Some good comments from cobkits, he probably explains it better.
http://rollitup.org/t/introducing-cobkits-com-specializing-in-diy-and-citizen-cobs.916763/page-162
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Thak you, great explanation from cobkits.
 
Tastybudz024

Tastybudz024

Active Member
Vehlor said:
Hello

The area of my cabinet is almost 4 square feet (28" x 20") but it is only 34" tall. I want to run 2 x CLU048-1818 or 2 x Vero 29 (50volts) at 80 watts each for a total of 160 watts which should give me over 900 ppfd. Heat sinks are going to be Alpine 64 or 11(cheapest) . I plan to get 3500K 80CRI (maybe 3000K).

1- Is my cabinet tall enough for COBS?
2- What reflector should I use if I go with Vero.

***at first, since I am on a tight budget, I wanted to use a single CLU058-1825 and run it at 140 watts***
3- This is bad idea, right?
4- Assuming it is not a bad idea, is the alpine 64/11 enough for cooling it since it will be less than 90 heat watts?


Thanks in advance for your advice and please excuse my English, it is not my mother tongue.
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Just start either training or pruning and start flowering at 5 6 inches
 
V

Vehlor

Member
Hi. I started this thread at the end of last year but started nursing school in January and free time suddenly disappeared from my life. Finally I got some time to keep working on this project, so here are some pics of the cabinet ans the light. I will post more pictures when I finish it. Thanks to everyone that helped me in these forum.
 
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