I look forward to those threads coming soon. I was imagining they could be mounted on bar array and pendant mounts as you mentioned, and I can imaging them been used in verticle boxes in the future similar to the verticle cool tube set ups where the lights are mounted vertically in the centre and the plants grown similar to the coloseum design grow box style set ups.
I thought the photo of the Janis plant you posted had some blue spectrum in the photo, I also make use of MH supplemental lighting during the strecth phase if growing with sativa dominant strains as you say it helps with keeping internodal length shorter and overall finishing height. @MadScientist See i’m not the only one !
I was doing some breif reading on the cob chips just earlier this evening, your post sparked an interest in me. so I understand the driver or power supply method now and the string etc which removes the use of solder used on standard LEDs (smd). I have heard a lot of complaints about those where the solder gets hot and individual leds part company with the circuit etc That has been what kept me off looking into them for a long time (reliability), but technology advances fast if the market is there.
Yes I am capable of hobby electronics to industrial level rewiring of buildings etc building my own power boards with timer delays etc for turning on 20 plus hps lights from one power distribution board to keep the ampere load down at switch on time etc
The green spectrums are something not visible to the human eye but I have read a little about it years ago but there was nothing really available at that time, and was contradiciting what I then understood that the plants do not react to green light. Difference been obviously the visible green light to humans and not the green spectrum in the ultra violet range. I have seen 1 bulb years ago that was in the green ultra violet spectrum used as a germicdal tube for water (Koi pond fish related item). Thers a lot more to it than meets the visible spectrum of the human eye
The picture of the 4ft looks to be solid from tip to toe so to speak so yes I would concur that they do grow rock hard nugs by penetrating the light into the canopy, and by the look further than the avergae 8" of a 600w hps
This is something i’m going to have to start seriously looking into. I cant say I have ever seen the diy kits ever marketed on my side of the pond and all I have seen on sale in the shops tends to be from your side of the pond and ready built blurples, but where there’s a will there’s always a way. I have seen ready built single cob untis in the £1000 - £1500 range in some grow shops recently I have seen individual cob bulbs available in some wholesale electrical retailers here just by doing a quick search, luckily my freind owns one and does a lot of trade with Asia
I await your thread now with eagerness and enthusiam while I do some more research of my own. Much appreciated and thank you for taking your time to post.
CREE is top shelf, but Bridgelux and CItizen are very comparable at almost half the cost. Samsung leads in mid-power LEDs, strips and such. 3500K spectrum is the sweet spot I think- good all-round spectrum for veg and bloom.
Once you get your basic rig in place, you can tweak with single-color diodes. I like Steves’ LEDs for them, but you can also find them on Ebay.
First person that got cobs instead of vipars😂 goodjob bro! You wont be disapointed. Unlike the people that bought the viparsXD where are they at again?XD
I wanted to share with you all my DIY COB light I built. The light is based on four CXB3590s. These diodes are 3000K and run at 36 volts. The 3500Ks are more efficient, but I wanted more red in my spectrum. These are attached to a 30 inch piece of 5.886 inch extruded aluminum heatsink from heatsinkusa. Active cooling is provided by four Noctua 140mm fans. Finally, the COBs will be powered by a HLG 240H C1750B Meanwell driver. This driver is dimmable and will run the COBs up to 1750 milliamps. With four COBs at 1750 mA, that’s about 250 watts. I took a bunch of pictures of the build. Enjoy!
First layout the COB holders. And punch the centers for easier drilling.
Next step is to mount the COBS. Take the COB holder and flip it over. The chip clicks in place, make sure the positive signs match up. Add a thin layer of thermal compound, then attach the holders firmly to the heatsink.
Next I wired them up in series, so negative from the previous COB goes to positive of the next COB and so on. I put a power cord on the driver and hooked up the positive and negative wires to the COBS.
Next I hooked up the fans and ran the wires for the remote driver. The fans are simply connected by shoving the rubber feet between the heatsink fins. They may be overkill, but they sure are silent!
Nice clean design @ReikoX. For those yet to take the plunge, that there is a 400w HPS-killer, delivering the same lumens at 30% less electricity and 30% less heat. Even light spread across the canopy, no degradation in light output for, say, the first 40,000 hours of use vs.1000 hours on an HPS bulb.
I like that you use the heatsink as the main structural component of the lamp. Two of those fans would have been plenty for the job - I’ve found even the slightest air movement across the sink provides significant heat mitigation over passive cooling.
I like to use these DC voltage step-down units on my fans, $1 on Ebay, and 1 inch sized. I just glue them onto the side of the fan housing.
3500k would be much more efficiant anyways:) that cob is only for people that think the light from the sun turns super yellow around harvest time. Personally ive never seen the sun go soo yellow that i cant take picturesXD
Agreed @lotus710. 3500K is the sweet spot I think for a universal veg-bloom COB. HPS bulbs are 2700K, 1750K is too far down the red spectrum and lumen/watt takes a big hit.
what Ive read and some experienced, in the mommy room it grows maybe a bit better than under 5000K , but 3500K was also super , but 90CRI is better, so its also probably more universal. just my two cents
good luck
How would 90 cri be better when thats layers of stuff put on the light to change the color? Technically a 70 cri would be better then a 90 cri because you get more light.
so yes I would concur that they do grow rock hard nugs by penetrating the light into the canopy, and by the look further than the avergae 8" of a 600w hps 
I have seen individual cob bulbs available in some wholesale electrical retailers here just by doing a quick search, luckily my freind owns one and does a lot of trade with Asia 
