Introducing CobKits.com - specializing in DIY and Citizen COBs

CobKits said:

if your plants can take it, and your heatsinks are sized appropriately, crank it up

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So if I have it dialed up and I want to dial it back down, it doesn't matter if I use the V or the IO to do it?

to the cobs, not really.

Vo will adjust lower than Io will

better to set and forget Vo at a voltage that is just slightly above what voltage is safe for an individual cob on that driver, and then adjust brightness with Io

DesertHydro said:

this will easily do a 4x4. half of the test tent(4x will be this light set to 630 watts at the wall or whatever the 630w DE CMH 3K-R hits at the plug. not gonna divide the tent up with a barrier so it wont be a true side by side even comparison but it should be close enough to get an idea if the results are way askew in one direction.

taking votes on which side will win

gonna try and divide up the clones as easy as possible.

The frame is 1" angle in .125(1/8") aluminum. normally i run lower wattage(37-50w) and 1 per sqft but this was a fuck around experiment and didnt wanna buy too much more shit and work with what i had. these will be somewhere between 60-65ish.

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Nice build! I'm working on a pair of lights myself. They are both mash ups of used and new parts, so it's not always pretty but they work. This one is for my 3x3, the corners are 3500's running at 75w, and the three down the middle are 4000's running at 50w each. I'll start veg with the 4000's, and probably flower with everything, if it's too much light, I'll shut off the 4000's. This light will definitely run further from the plants than I'm used to. I tend to run between 37.5w - 50w/sf, but this is an experiment.

The other light in the last pic is for my 2x4, it's a more complicated (and sadly sloppier) build. It also has three drivers on separate switches, and all of those cobs are running at 50w (I've still got more work to do on that one). With 8 of the 10 on during flower I'm running at 50w/sf, and with the other light with all the cobs lit up, I'm also at 50w/sf. With every cob going, that's about 990w burning in that last pic.

Humanrob said:

Nice build! I'm working on a pair of lights myself. They are both mash ups of used and new parts, so it's not always pretty but they work. This one is for my 3x3, the corners are 3500's running at 75w, and the three down the middle are 4000's running at 50w each. I'll start veg with the 4000's, and probably flower with everything, if it's too much light, I'll shut off the 4000's. This light will definitely run further from the plants than I'm used to. I tend to run between 37.5w - 50w/sf, but this is an experiment.

The other light in the last pic is for my 2x4, it's a more complicated (and sadly sloppier) build. It also has three drivers on separate switches, and all of those cobs are running at 50w (I've still got more work to do on that one). With 8 of the 10 on during flower I'm running at 50w/sf, and with the other light with all the cobs lit up, I'm also at 50w/sf. With every cob going, that's about 990w burning in that last pic.

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those cool! building the lights is half the fun

Humanrob said:

Nice build! I'm working on a pair of lights myself. They are both mash ups of used and new parts, so it's not always pretty but they work. This one is for my 3x3, the corners are 3500's running at 75w, and the three down the middle are 4000's running at 50w each. I'll start veg with the 4000's, and probably flower with everything, if it's too much light, I'll shut off the 4000's. This light will definitely run further from the plants than I'm used to. I tend to run between 37.5w - 50w/sf, but this is an experiment.

The other light in the last pic is for my 2x4, it's a more complicated (and sadly sloppier) build. It also has three drivers on separate switches, and all of those cobs are running at 50w (I've still got more work to do on that one). With 8 of the 10 on during flower I'm running at 50w/sf, and with the other light with all the cobs lit up, I'm also at 50w/sf. With every cob going, that's about 990w burning in that last pic.

View attachment 4058256 View attachment 4058255 View attachment 4058257

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note that your design has more cobs in the middle and deserthydros has less in the middle

seems like a great spot to discuss coverage and design strategies!

DesertHydro said:

those cool! building the lights is half the fun

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you only say that cause youre smoking your last crop while building your next rig lol

CobKits said:

note that your design has more cobs in the middle and deserthydros has less in the middle

seems like a great spot to discuss coverage and design strategies!

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I'm not an expert, I'm just making this up as I go along based mostly from things I've picked up on this forum. The 2x4 light is fugly and it's using parts from multiple previous builds, for some of these cobs this is the fourth build they've been part of. Because there is so much scavenging (or recycling...) in this one, there are several different types of wire involved, and I did things like cut up an old extension cord for wiring in the power. But hey, when I flip the switches she lights up. Not everything can be beautiful. Odds are good that since I can't go any further with light for this space, next time I get the urge to build a light instead I'll strip this one down and rewire it from the ground up.

The (2) 5000's are on one driver, the (2) 3500's and (2) 4000's on another, and the (4) 3000's on a third driver. I'd start babies under the 5000's, when they start to fill out I'll throw on the 3500/4000's, and when I flip to flower shut off the 5000's and turn on the 3000's. In flower the remaining 8 cobs are 11" apart on center (front to back and side to side), for an even spread. These are all B drivers, but I still need to wire up the pots so I can dim them. For both of these builds I took my small drawings and did 1:1 full size drawings -- and in both cases that helped me immensely.



The 3x3 light went through some design changes on paper before any metal was cut. I thought about using 6 cobs at 75w each, and then decided to go with four @ 75w and three at 50w. Since this light is wired in parallel, it can relatively easily be converted to 9 @ 50w each if I find that running them at 75w is too much for the plants. The overall strategy was trying to balance hot spots from light overlap without getting the cobs too close to the edges of the tent. I haven't hung it in the tent yet because I'm finishing up some plants in there and I don't want to mess with that. It'll be another 10 days or so before I see how it lights up the space its built for.

I wish that these drivers were the B-type with the external potentiometers, that would make my life so much easier. I don't even know if parallel drivers are available in a "B" format?

CobKits said:

note that your design has more cobs in the middle and deserthydros has less in the middle

seems like a great spot to discuss coverage and design strategies!

Click to expand...

i did this for two reasons. theres always a hot spot in the center of every light and I only had 10 COBs where I would normally do 16 lol.
1 per sqft is great at 37.5w each but since they are low 60s I figured I would space them as evenly as possible.

when I upgrade my lights to DE I'm gonna convert all my hoods to aircooled COBs like my last rig. haven't ran it yet but its set for 666w so it should be a monster

comparing lights by watts consumed is not much of a comparison. You need to treat the plants differently under the different lights. The LEDs will be making considerably more light, which could skew result towards the negative, as much as it could towards the positive depend on distance to the plants, etc.

Maybe next run, compare them with the LED running below 500 watts, say 450, probably closer to an even match then

It will be interesting however, to see your results!

DesertHydro said:

this will easily do a 4x4. half of the test tent(4x will be this light set to 630 watts at the wall or whatever the 630w DE CMH 3K-R hits at the plug. not gonna divide the tent up with a barrier so it wont be a true side by side even comparison but it should be close enough to get an idea if the results are way askew in one direction.

taking votes on which side will win

gonna try and divide up the clones as easy as possible.

The frame is 1" angle in .125(1/8") aluminum. normally i run lower wattage(37-50w) and 1 per sqft but this was a fuck around experiment and didnt wanna buy too much more shit and work with what i had. these will be somewhere between 60-65ish.

Click to expand...

DesertHydro said:

i did this for two reasons. theres always a hot spot in the center of every light and I only had 10 COBs where I would normally do 16 lol.
1 per sqft is great at 37.5w each but since they are low 60s I figured I would space them as evenly as possible.

when I upgrade my lights to DE I'm gonna convert all my hoods to aircooled COBs like my last rig. haven't ran it yet but its set for 666w so it should be a monster

Click to expand...

pop22 said:

It will be interesting however, to see your results!

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@DesertHydro - will you have a thread or journal where you are sharing this grow?

Humanrob said:

@DesertHydro - will you have a thread or journal where you are sharing this grow?

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I would get something going here pretty soon. The de 630 doesn't show up till the 21st

pop22 said:

comparing lights by watts consumed is not much of a comparison. You need to treat the plants differently under the different lights. The LEDs will be making considerably more light, which could skew result towards the negative, as much as it could towards the positive depend on distance to the plants, etc.

Maybe next run, compare them with the LED running below 500 watts, say 450, probably closer to an even match then

It will be interesting however, to see your results!

Click to expand...

I think running them at the same wattage is there only fair comparison. You say it like the cobs already have it in the bag. I tend to agree with you but the new DE stuff is supposed to be more efficient as well. I will also have the plants tested at the lab just to be extra thorough

what are these leads for on my driver? is it for a POT even though it has dimmers built in?

RC+ / RC- are for remote on / off control:

Power on : "High" >2 ~ 5V or Open circuit
Power off : "Low" <0 ~ 0.5V or Short circuit


+5VSB is a 5v supply ([email protected]) - which I guess you could use to power a controller to turn the driver on or off (ground would be RC-).

guy_incognito251 said:

RC+ / RC- are for remote on / off control:

Power on : "High" >2 ~ 5V or Open circuit
Power off : "Low" <0 ~ 0.5V or Short circuit


+5VSB is a 5v supply ([email protected]) - which I guess you could use to power a controller to turn the driver on or off (ground would be RC-).

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so if i wanted to add an on/off switch would i just use the two brown and black and cap the yellow?

DesertHydro said:

so if i wanted to add an on/off switch would i just use the two brown and black and cap the yellow?

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It should work like that but there isn't very much info in the data sheet (it just lists these next to function under the specification) and I don't have one of those drivers. The remote off would turn the driver output off - the driver would draw less then 0.5W in this state (maybe more if you were using +5V SB)

I vaguely recall something about remote dimming but thought that was D series drivers? Would these be dimming (remote pwm?) Or are the just on/off?

I just capped them with wagos for now. gonna throw a cool toggle switch on this bitch so I have an on and off. anyone know if I need some sort of relay or just connect a switch?
this hlg600 has a nifty blue LED on it that the others don't. I feel special. driver gets mounted tomorrow and then I will clean up the wiring and get it hung. 600+ watts of fuck your retinas

DesertHydro said:

I just capped them with wagos for now. gonna throw a cool toggle switch on this bitch so I have an on and off. anyone know if I need some sort of relay or just connect a switch?
this hlg600 has a nifty blue LED on it that the others don't. I feel special. driver gets mounted tomorrow and then I will clean up the wiring and get it hung. 600+ watts of fuck your retinas
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I'm not an electrician but I think a properly rates switch should be fine. I used one from Home Depot. But I'm not sure if I'd do it again. The switch is one more thing to fail

DesertHydro said:

I just capped them with wagos for now. gonna throw a cool toggle switch on this bitch so I have an on and off. anyone know if I need some sort of relay or just connect a switch?
this hlg600 has a nifty blue LED on it that the others don't. I feel special. driver gets mounted tomorrow and then I will clean up the wiring and get it hung. 600+ watts of fuck your retinas
View attachment 4060270 View attachment 4060271 View attachment 4060272

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Love to see a PAR map of that beast !! Nice work.