Economical multi LED Chip Projects for Growing

110 Volt AC Driverless COB Lamp Test Update
I took some temperature readings off the AC COB lamp today, it was running steady on a veg plant since I put it on test and the heatsink temp was 45 C. I have a .22 amp 120mm fan cooling it, but could upgrade to a .30 amp fan and cover the tops of the heatsink with plastic to better direct airflow, this should bring the lamp down to the 40 C range. The vendors claim an efficacy of 100 - 120 lumens/watt with a CRI of 80, but I dunno how much credence to give to that. I didn't test the power consumption of each COB, but tutaj5 (using the 220V version) further up in the thread, says the 50 watt AC COBs draw 65 watts, which would explain where the 50 extra watts are going in my 3 COB lamp, even though it runs at 110 volts.

110 Volt AC Driverless COB


If these ebay COBs can produce a 100 lumens/watt, then a COB running at 65 watts must be putting a minimum of 60 watts into light, say 6000 lumens per WW COB. Considering the price (under $2!), that's not bad, some folks only want to grow a couple of plants and unlike a larger operation, efficiency doesn't matter so much. Start up costs are a major barrier to many who might like to build grow lights, but most folks can afford $20 to 50 bucks for COBs and other parts. If you use AC COBs to make a cheap grow light, heat sinking will be the biggest expense, but you can keep costs down by getting creative going to junk yards and repurposing other things. The local metal supply or machine shop is another source of cheap aluminum extrusions, like heavey C and D cross sections, depending on the profile, size and thickness prices can range from a $1 to $5 a foot. If you live in the states mail order heatsink extrusions with free delivery are an option too.


If you build using these COBs make sure to check them for ground faults with a multimeter before and after installation. And for Christ's sake USE A THREE PRONG PLUG AND GROUND THE GREEN WIRE PROPERLY TO THE HEAT SINK. Follow the Line Neutral wiring conventions and if you don't know much about that, google it or watch a youtube video and make sure you wire the COBs and plug right. Also, after the light is up and running take yer multimeter and check for current leaking from the heat sink to ground. Better safe than dead!

I just checked if they are safe by touching the heatsink also I have no grounding in my house so I cant ground them. I am not afraid to die.

tutaj5 said:

I just checked if they are safe by touching the heatsink also I have no grounding in my house so I cant ground them. I am not afraid to die.

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I admire your courage! Thanks for the info on the COB power consumption, but that means you must own a multimeter and can check for grounds safely. If your older house doesn't have electrical grounding, then you can hook up a ground wire to a heating or water pipe or radiator. If that's not an option, drive an iron rod 3 feet (1 meter) into the ground and run a ground wire from it to your grow. You appear to be using 220 volt COBs so I wouldn't fuck around when it comes to grounding the heat sinks. Ya can't smoke yer dope if yer dead.

DIRT CHEAP JUNK YARD 6 AC COB GROW LIGHT
I was rummaging around the workshop and ran across this cruddy 45" section of rectangular tubing that I acquired at the junkyard for I think $5. The rectangular aluminum tube has 3/16" thick walls and is 45" x 4 1/4" x 2", it looks like crap but will clean up nicely.
I was thinking of putting 6 X AC 50 watt cobs on it, cutting a large hole in the back and mounting a powerful 1 amp fan on the center rear of the tube. An old computer power cord and a 1 amp wall wart to power the fan would make up the rest of the package. The only question is, can this piece of aluminum keep 400 watts worth (6 ea.) of cheap AC COBs cool enough with a good breeze blowing through it.

Here's what I mean, you can see the fan and wall wart I'm considering for this possible project in the background.


If I used warm white cobs, they would cost less than $12 CDN, for mixed spectrum less than $20. I got the fan (along with a bunch of dead computer power supplies) for free from a local computer repair shop and the 12 volt wall wart to run it for a buck at a thrift store, same for the computer power cord I would use to hook it up. So the cost of this $400 watt grow light is under 30 bucks with a mix of CW and full spectrum grow COBs, or less than $20 for the same lamp built with CW COBs.

I don't know about you, but a 400 watt DIY COB grow light for $20 - $30 CDN (less in US bucks) is something new to this world in my opinion. What a staggeringly low cost for such a powerful light, this puts a DIY grow light in the price range of almost everybody.

DIRT CHEAP JUNK YARD 6 AC COB GROW LIGHT Continued...
I was thinking about figuring out the heat load on the 45" tube which has an internal area of 4"x2+2"x2 X 1" = 12sq in per linear inch (12x45=540) or 540 square inches total interior area for the tube, minus 16 square inches for the fan cut out, for a final total area of 524 square inches. The COBs have a claimed efficacy of between 100 and 120 lumens per watt, this translates into approximately 30% efficiency, so for every 100 watts used by the COBs 70% of the energy must be dissipated into heat. Since there's 390, say 400 watts of power used by the 6 COBs, this should produce about 280 watts worth of heat. Dividing the watts (280) by square inches of interior tube surface area (524) 280W/524=.52 watts, or about a half a watt per square inch. Since the tube will have a stiff breeze blowing down it, I figure it should be able to handle more power, but this much light is more than enough for the area it would cover.

I just saw on one of the vendors sites that the light output for these 50 watt AC COBs is 4200 lumens/ 50 watts = 84 lumen/watt + 15 watts for the driver= not the most efficient LED grow light. Nonetheless paying for power is a lot cheaper than paying for pot and these can get ya going real cheap. The Junkyard lamp would have a light output of 25,200 lumens (white light only), but this is capable of growing a very nice plant or two.

I dont think thats enough surface area for that much power, it may be functional but remember higher temps mean less light output. I may be wrong tho.

But i agree in that these cheap COBs are a great solution for those starters/budget growers that just want 1 or 2 plants and just want some homegrown dope without spending a lot on light equipment.

tutaj5 said:

But i agree in that these cheap COBs are a great solution for those starters/budget growers that just want 1 or 2 plants and just want some homegrown dope without spending a lot on light equipment.

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That's my primary focus, helping poor folks grow their own with cheap DIY lights. Recreational growing will be legal in the spring here (Canada) with a 4 plant limit, so I expect to give away the AC COB lamps (four of them) to friends. I figure we will be allowed to flower 2 plants at a time, but since I can get a pound off a plant this shouldn't be an issue. I use air pruning grow bags filled with coco coir and 20% perlite and hand feed every day with 20% run off. Feed 2 days and flush with calmag + silicate on the third, the plants drink 5 liters+ a day when into flower. I spread the plant out and flatten the canopy using a grid attached to the pot with bamboo sticks and wire ties and extend the veg to fill the grid. I also lollypop the small lower branches under the grid and defoliate starting a couple of weeks before harvest. Two pounds of bud every couple of months should keep most people going. If you smoke more than a pound of good bud a month, seek help!

I stripped the old components off the aluminum castings to use on a water cooled system and they were just sitting idle, so WTF why not try some AC COBs on em. I dunno if I'll build the junkyard light, I'm curious to see how hot it would run, but I don't really need it, since I've got plenty of better more efficient lights, though in the spring someone I know might want a lamp and it might just happen. Between stripped down dollar store 100 watt light bulbs and these COBs, anybody can build cheap effective grow lights, all they need to do is figure out a way to keep them cool for an affordable price. I figure that these AC COBs are just the beginning for these kinds of integrated components, they will keep getting better and more efficient over time. The pace of change and innovation in this field during the last couple of years has been astounding and will accelerate.

DIY-HP-LED said:

I don't know about you, but a 400 watt DIY COB grow light for $20 - $30 CDN (less in US bucks) is something new to this world in my opinion. What a staggeringly low cost for such a powerful light, this puts a DIY grow light in the price range of almost everybody.

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Unfortunately with efficient COBs you could run at 250W and have the same amount of light. That 150W translates into 150 a year in electrical cost.

A replacement in 7 Citizen 1212 COBs would cost you around $80 add $65 for the driver. So after a year of extra running costs you'd already be cheaper off buying those instead of supposedly "cheap" COBs.

wietefras said:

Unfortunately with efficient COBs you could run at 250W and have the same amount of light. That 150W translates into 150 a year in electrical cost.

A replacement in 7 Citizen 1212 COBs would cost you around $80 add $65 for the driver. So after a year of extra running costs you'd already be cheaper off buying those instead of supposedly "cheap" COBs.

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wietefras said:

Unfortunately with efficient COBs you could run at 250W and have the same amount of light. That 150W translates into 150 a year in electrical cost.

A replacement in 7 Citizen 1212 COBs would cost you around $80 add $65 for the driver. So after a year of extra running costs you'd already be cheaper off buying those instead of supposedly "cheap" COBs.

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Agreed! The only advantage is in startup, hopefully one would replace the AC cobs with something better over time. A low income person could still save money over buying pot though, and then use the savings on something like you describe. It could be a way for some people to get somewhere better over time.

CobKits said:

ive got citizen 1212 on my site starting at $7-$8

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I sent you an email about shipping charges for sending a half dozen CLU 048 1212 COBs to Canada. Recreational growing will be legal here in the spring and it will be a year before commercial growers are up and running. So I would expect many folks will get their pot quicker if they grow it than from yet to be established businesses. A huge potential for business, the problem is many things are more expensive to ship from the states than the purchase price! If more attention were paid to lowering these costs where possible and communicating that fact to Canadian customers, you could see more business from up this way. Mailing COBs in padded envelopes to Canada should be relatively inexpensive and secure, who knows, some might opt to have other items like drivers shipped too, if they could get a deal on the COB shipping.

If you find you can ship COBs at least to Canada for a reasonable price, why not try to attract some Canadian business by running a free COB shipping to Canada special. You can charge more for the Canadian special to cover costs. Naturally this would attract Canadian customers for holders and drivers too. I expect a brisk business up this way in such things come spring. Tailor your offer for the 4 plant limit market in Canada and if you only offer a deal on the COB packages,and say holders (low shipping cost items), it will attract other business. You have a very good price on quality "Cree Killer" COBs, so it should be popular.

'uninsured cobkits canadian shipping is cheap..his cobs are already rock bottom

OLD MOTHER SATIVA said:

'uninsured cobkits canadian shipping is cheap..his cobs are already rock bottom

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He emailed me the shipping charges and I agree the costs are low, a real good deal. Most of the time shipping charges to Canada are outrageous with a lot of vendors, they might ship cheaper, but the website usually has some high generic price. I figure we'll be doing business soon.

Water Cooled Lamp(s) Citizen COB Upgrade
A friend and I recently got together on an order for some Citizen CLU048 1212 2700K COBs from CobKits.com for the best price I've seen online so far. The vendor was almost out of the 3500K Gen 5 90 CRI's so we opted for the 2700K which can be easily and cheaply be supplemented in the blue end of the spectrum by pairing them with 10 watt CW 5000-6000K LEDs. I sure hope shipping insurance and Canadian customs don't blow the price through the roof though. Still waiting on a final cost and I guess I won't know until delivery if customs will ding us.

So, I'm gonna upgrade both the large and small water cooled lights and replace all the floodlight COBs with Citizen COBs. I already have 9 Citizen CLU048 1212 3500Ks on the big water cooled rig, 3 COBs running @1 amp each on the 3 X 5 ft long water cooled bars. So I'm gonna alternate 2700K and 3500K COBs (3 of each) by adding 3 more 2700K COBs to each of the three bars. I'm gonna run them in pairs off of 100 watt drivers at 1500ma (probably a little less than 50 watts each) on a water cooled heat sink running at 25 - 30 C

I addition I'm gonna upgrade the 6 floodlight COBs on the small 24" x 24" water cooled light and run the Citizens at 1500ma on it as well. Stay tuned, I never really showed the construction details of the big water cooled rig, so the COB upgrade will be a good chance to make a couple of other changes, take some pics and share some info. I took the summer off from growing (and most everything else!) so I won't start flowering until the end of September, I have the lamp on the bench for other work (improvements) and I might as well upgrade the COBs too.

Someone was selling gen 5 citi 1212's for $5. Unfortunately I missed it.

He does have some "version 3" still available: http://www.ebay.nl/itm/5x-CITIZEN-LED-Chip-3000K-CITILED-cob-module-CLU044-1212B8-303H5D2-Version-3-/222509957323

Not sure how well those perform compared to version 6 though. Still, I'll bet they are a lot better than the "China 100lm/W COBs" and for only 16 euro you'd have the COBs for a 125W to 150W light.

For cheap and cheerful, I'd advise the TCI ledstrips in his store.

wietefras said:

Someone was selling gen 5 citi 1212's for $5. Unfortunately I missed it.

He does have some "version 3" still available: http://www.ebay.nl/itm/5x-CITIZEN-LED-Chip-3000K-CITILED-cob-module-CLU044-1212B8-303H5D2-Version-3-/222509957323

Not sure how well those perform compared to version 6 though. Still, I'll bet they are a lot better than the "China 100lm/W COBs" and for only 16 euro you'd have the COBs for a 125W to 150W light.

For cheap and cheerful, I'd advise the TCI ledstrips in his store.

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We were looking at the great deal there on Gen 3 CLU044-1212B8-303H5D2 CRI 90's, but I want to use Gen 5 CLU048 CRI 90's across the whole grow. They will electrically match the 3500K ones I already have on my big light. The Guy at CobKits.com will ship to Canada insured for $23 (small stuff like COBS & holders), but I'll have to find out about customs. We're suppose to have "free trade" (for corps anyway), but I think this has to do more with collecting the sales tax. I would still get dinged by customs wherever I go, except for chinese stuff it seems, but they bullshit the customs label description, I have received many "gifts" from China.

The CLU044-1212B8 CRI 90's have an awsome spectrum with 660 nm at 90% of output and pretty good in the blue end too. They are real cheap and highly effective and 3 would run nicely on a cheap 100 watt driver at about an amp each.


http://www.ebay.co.uk/itm/222509957323

Health Alert
Was just reading this online...
If ya wanna stay sharp, stay high! Pot might not be so great for young folks brains, but if yer over 50 (if yer not now, you will be, if yer lucky), it's a different ball game. Lot's of new research coming out on the health benefits, particularly for older folks. It may slow down or stop not just alzheimer's, but general age related neural decline, you won't have a 1000 yard stare and drive at 10mph in a few years. When it comes to pot, I think it'll end up as, "Old Farts Rule"! Imagine what the media/political reaction will be to a successful clinical trial for alzheimer's, the health websites, TV, health magazines and newspapers will be all over it. Why even ole Jeff Sessions will be high, either that or watch his brains run outta his ears. Other research shows there's every indication that it is highly effective for brain injuries too by preventing brain cell death and aiding recovery. So there's good news for the youngins after all. They've done (and are doing) a lot of work with old folks and pot in Israel and recently greatly expanded medical access.

https://www.sciencedaily.com/releases/2017/05/170508112400.htm

One of the best deals on 100 or 70 watt enclosed drivers I've seen online. $10 bucks US gets you one, but I can't speak to the quality. I ordered 3 to try out.

http://www.ebay.ca/itm/10W-20W-30W-50W-100W-Waterproof-High-Power-LED-Driver-Supply-LED-SMD-Chip-Bulb/401388314534?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=20140620091118&meid=059a501186fd48028c3e95d137702ea2&pid=100005&rk=6&rkt=6&sd=172726808490&_trksid=p2047675.c100005.m1851

Another one, toss the COB, or run two in parallel off it.
http://www.ebay.ca/itm/172726808490

Using enclosed drivers greatly simplifies your build, just add heatsinks, fans and a frame to mount everything on.

The Cheapest Quality COB 350 Watt Grow Light Build

Here are some of the main parts that will build the cheapest DIY high quality 10 COB grow light that I know of.

The COBs
These Citizen 81 watt 3500K 90 CRI COBs are around $20 US for 5 pcs, so for around forty bucks US you can get 10 COBs
The CLU044-1212B8 CRI 90's have an awesome spectrum with 660 nm at 90% of output and pretty good in the blue end too. They are real cheap and highly effective and 2 would run nicely on a cheap 70 watt driver at about an amp each. These COBS wouldn't even need to be supplemented, since they pretty well cover all the spectral bases. Here's the data sheet

The Drivers
The 70 watt version of these enclosed drivers will drive the COBs safely at nearly the specified amperage when run in parallel pairs of off one driver. So to drive the 10 COBs (5 pairs) you would need 5 drivers and buying a spare driver might be wise. So say 6 drivers including a spare at $5.49 US each, or about $30 bucks US for drivers including a spare. When you use 70 watt drivers, if one COB in the array becomes disconnected or fails (very unlikely with these COBs) the driver won't produce enough current to damage the remaining COB. These 2100ma 38 volt drivers are a cheap way to drive good quality COBs safely, or you could run the COBs hotter and safely (1500ma) with individual 50 watt drivers, but 70 watts driven in pairs is cheaper, just as safe and keeps you closer to peak COB efficacy.

http://www.ebay.ca/itm/10W-20W-30W-50W-100W-Waterproof-High-Power-LED-Driver-Supply-LED-SMD-Chip-Bulb/401388314534?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=20140620091118&meid=059a501186fd48028c3e95d137702ea2&pid=100005&rk=6&rkt=6&sd=172726808490&_trksid=p2047675.c100005.m1851

So the essentials for this 10 COB 5 driver lamp cost about $70. US, not bad. Add in another $40 for Ideal COB holders and good thermal paste and you won't even have to solder anything.

If anybody knows of a cheaper way to drive these COBs speak up. Running them in series with Meanwells would be best and about 94% efficient, but this is just as good and cheaper, it's just about 6% less efficient than top drawer. We're looking for low cost quality light and that counts on the COBs, the drivers have a claimed efficiency of 88%'', I'll put that particular claim to the test soon. The key advantage to these drivers is cost and they deliver anywhere for free or cheap.

Everything else is fans, frames and heat sinks, depending on where you live, users choice. As long as it cools the COBs and spreads the light with about a 8"- 10" COB spacing. This lamp should provide about 35,000+ lumens to a garden and the light intensity (or PAR if you gotta meter) depends on the COB spread and distance from the plant(s).