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CobKits

Well-Known Member
So I have 3 leads on my potentiometer.

I'm going to combine the positive DIM leads on my meanwell drivers, and the negative leads together, but what leads do I attach this Positive and Negative to? Does it matter which one I use?
use a meter. one of those is usually just a ground. you should be able to measure resistance across 2 of the terminals on the pot which changes with turning the dial. these are the ones you want polarity doesnt matter
 

Axle4worc

Well-Known Member
Need to learn how to use my cobkits lights.

Veg tent
4x citizen 1818 3000K gen 6 cri 80
hlg-120h-48a driver Cranked all the way up.
SST 133 heat sinks
Angelina reflectors.
Spaced 9.5" from each other and sides of tent.
24"x48"x50" tent.
Minimum distance 18" from top cola.
Cheap lux reading 30-35k at top cola with reflectors on.
10 week old auto. 7 weeks into flower.

My plants were fine with the reflectors on. When I took the reflectors off, within 36 hours, the top leaves were all burnt. My guru mentor, who pointed me at these lights, said my plant should not have burnt. Could it have been the overlap when I took the reflectors off? Is there some other way to burn them? I am about to start some new seeds in Coco and don't want to kill them. I have a lux app on my phone but no other way of measuring.

My flower tent with her sisters has.

8x citizen 1818 3000K gen 6 cri 80
2xhlg-185h-48a drivers Cranked all the way up.
SST 133 heat sinks
Angelina reflectors.
Spaced 11.5" from each other
60x60x70 tent.
Minimum distance 24" from top colas.

No burning issues.
 

Axle4worc

Well-Known Member
I would expect the opposite, maybe the plants were starved for light and got shocked? usually in a tent light is most uniform without reflectors in my experience
So, with reflectors, these lights are not bright enough with a hlg-120h-48a in a 2x4?

No clue what shock looks like. This is what it looked like just before I chopped it. Could have been another kind of abuse too. Only thought it was the lights because that was the thing I changed.
 

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CobKits

Well-Known Member
I plan on doing this in about a month, 2 cxm22s on a single heatsink, one 3000k 80 and a 3500k 90 to get two peaks in the red.

What does the simulation for that look like on that graph? I suspect it is a bit better than the 2 1216s.
im gonna rerun cxm22 i have 4000k 80 on the way (i do have one sample in that color ive run before but its 6+ months old, that plus id rather run a chip from an actual production lot than a pre-production sample).

that sounds like a cool setup. put em on different drivers for spectrum control!
 

eyderbuddy

Well-Known Member
Need to learn how to use my cobkits lights.

Veg tent
4x citizen 1818 3000K gen 6 cri 80
hlg-120h-48a driver Cranked all the way up.
SST 133 heat sinks
Angelina reflectors.
Spaced 9.5" from each other and sides of tent.
24"x48"x50" tent.
Minimum distance 18" from top cola.
Cheap lux reading 30-35k at top cola with reflectors on.
10 week old auto. 7 weeks into flower.

My plants were fine with the reflectors on. When I took the reflectors off, within 36 hours, the top leaves were all burnt. My guru mentor, who pointed me at these lights, said my plant should not have burnt. Could it have been the overlap when I took the reflectors off? Is there some other way to burn them? I am about to start some new seeds in Coco and don't want to kill them. I have a lux app on my phone but no other way of measuring.

My flower tent with her sisters has.

8x citizen 1818 3000K gen 6 cri 80
2xhlg-185h-48a drivers Cranked all the way up.
SST 133 heat sinks
Angelina reflectors.
Spaced 11.5" from each other
60x60x70 tent.
Minimum distance 24" from top colas.

No burning issues.
i have pretty much the same setup except that i'm using cxm22's, and It happened to me too when i transferred a plant that was grown under CFLs. I put my plant 11 inches under and 6 inches of top cola got burnt. That didn't last long though, a few days later the plant got used to it... But i learned that i need to do these kind of changes pretty slowly.

as of right now i'm vegging a bunch of seedlings 14 inches away without problems, it seems that they just need to get used to the intensity.

btw, i think you'd have a better spread without the reflectors
 

CobKits

Well-Known Member
i have pretty much the same setup except that i'm using cxm22's, and It happened to me too when i transferred a plant that was grown under CFLs. I put my plant 11 inches under and 6 inches of top cola got burnt. That didn't last long though, a few days later the plant got used to it... But i learned that i need to do these kind of changes pretty slowly.
youre not alone... after 25 years im still re-learning the details of our new tech
 

pop22

Well-Known Member
they don't have light burn. Looks like end of life N depletion and or ph problems to me

So, with reflectors, these lights are not bright enough with a hlg-120h-48a in a 2x4?

No clue what shock looks like. This is what it looked like just before I chopped it. Could have been another kind of abuse too. Only thought it was the lights because that was the thing I changed.
 

sixstring2112

Well-Known Member
watched the most excellent techtalk with @Greengenes707 and @Growmau5 today, (http://tinyurl.com/techtalk5) and was thinking about their observations on applicability of certain chips depending on application current

their consensus was cree has an advantage at low current, and veros/citi/luminus had an advantage above 2A or so. This motivated me to get going on the sphere (new setup, identical active cooling on real heatsinks on all chips to give most accuracy esp at high currents. I figured out a way to slightly modify the heatsinks instead of attempting to cut the sphere. I plan on starting a new thread for just sphere data and discussion soon)


1216 vs. 1818gen6 vs. CXB3590DB (cree was fresh from cutter this week and is highest bin available in that color AFAIK)
View attachment 3921528

I thought the 1216 would do a little better TBH. about 3-4% less relative efficacy than the CXB in the usual 30-60W range. 1216 needs to be run at about 80% of the wattage of a CXB to have an equivalent efficacy (not bad for 50% of the price tho, if you can keep heatsink costs under control)

CXB with a very slight edge in efficacy (1-2% relatively) below 30W. Not as pronounced as i would anticipate.
1818 essentially equal to CXB from 30-50W where then 1818 pulls ahead above 50W
as we often see, chips are converging below 30W, the 1216 and 1818 are almost identical.

so this is congruent with GG's observations (though the crossover is probably shifted, he was probably talking gen5 citi and not sure which vero. I have gen7 V29 and will run soon on new setup. i expect vero C to be right there with 1818 and Vero B and D to be closer to CXB, just a guess)

Worth noting that CXB has the least dies of all of those chips (144). A testament to Cree's die quality for sure, and a solid performer esp at low current.

from here on out i will include spectra with my tests. raw data available in excel if somebody wants to get all QER with it. 1216 and 1818 similar as expected. CXB with an ever-so-slightly broader phosphor peak and the blue peak is a little lower than the citis
Would love to see the 50v and 69v veros included in your test. :)
 

caretak3r

Well-Known Member
1216x2 simulated. for same chip cost as cxb you could put 2 on a pinfin at half the wattage per chip (same total wattage per heatsink) for better efficacy. im not sure why multiple chips on a heatsink arent a thing. if you utilize the lens holes in a 133mm heatsink, you can put 4 35mm holders on it (on the 133s i currently have, the 4th chip falls over the 7mm cable hole- i will offset it 45 deg next time.

i only know of one person doing this, and its 2 regular cobs+1 blue cob on a pinfin

View attachment 3921541
I can't like this enough. Given your input that most of the cobs are converging in efficiency < 30W, I'm thinking the next evolution of growing with COBs will go this direction. (more cobs, close together, driven soft). Should we start looking at some of the later generation cheapy cobs (100W driven @ 20W like @SupraSPL tested quite some time ago -- I gotta go find those old posts). I'm guessing even the Chinese copy cats have upped their game in the last 2 years.
 
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kaivorth

Active Member
Is it safe to clean the lens of a COB with water? The lens seems slightly "sticky" and a couple hairs are stuck. Don't want to damage anything.
 

CobKits

Well-Known Member
another round of sphere tests. lets call this preliminary data as tests done on different days give different results due to variations in ambient temp.(shop is a warehouse with big rollup doors) Im getting antsy because it takes longer to mount the chips for testing than it does to run the test and i have all these fine specimens sitting here ;)

Today was more normal temps but the chips i ran the other day was a much colder day. i want to say -5C difference in ambient temps

"cold day" tests (will bias results slightly higher):
1216
1818
CXB3590 "A"

"warmer day" tests:
Vero 22C
Luminus CXM22
Luminus CLM22 (the alleged 36V counterpart of the CXM22, ~$1 cheaper)
CXB3590 "B" (same chip as "A" tested on different day)

upload_2017-4-10_22-42-32.png

observations:
-wow CXM22 dominating across the board at all currents. this chip was new to me. I dont stock 4000k 80 (tho i initially screened that color from a pre-production sample - this was a regular off the shelf chip from digikey). 1818 is catching up with it at 130W but probably not really as 1818 was a cold day test

-I was interested in Vero22 as it is the same package size as the CLU048 and CXM22, it does well at high currents but lacks at low currents for some reason. On a same-day test its crossing CXB3590DB above 50W but still lags behind the similarly priced CXM22 and also the CLU048-1818. Definitely living up to Vero's reputation as an excellent high current chip with great thermal characteristics

-CXB3590 day 1 and day 2 tests were similar trends, and you can see that ambient temp difference definitely having an effect (selling point for ducted hoods? ;)). Again, you can see why i dont like to compare chips tested on different days, were seeing a 1.5-2% difference in relative output

at 50W were seeing a whopping 7% difference between top and bottom chips - so really any of these chips will do fine... chip cost really comes into play at that point. I would definitely say all these chips are in the same "class" of package size and relative die count. It will be interesting to see what happens when we bring out the big guns with larger packages and higher die count. The chips on deck include gen 6 CLU058-1825 and CLU058-3618, as well as Vero29 V7 and Luminus CXM27 and CXM32.

will also be running 1212 gen6 mostly in comparison to the similar 1216. i still have a warm spot for these chips as economical low-current champs.

Once we get to the formal test I hope to run dupes on most of these to check for output/bin variation, i think I have 2 of all of the chips except for CXM27 and CXM32

I am happy with the sphere performance, it seems to be giving more reliable low current data than the open-air tests
 
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