IC Driven COB LEDs Experiences? Advise?

[ssj4jonathan]

Chinese full-spectrum lights are magenta in color and emit 380nm-840nm light with max peak output at 420nm and 640nm. And broad spectrum is the sunlight at high noon, which is around 5000K.

I've bought from that seller, and he has done me right - he even sent a replacement COB no question asked, when I told him one of them had a string shorted to the backplate (it works fine, just can't ground the heatsink its on).

To clear things up, baoshengk did refund all my money, and I got to keep the 6 20W COBS. And my overall experience with him was pleasant and eBay is a safe place to buy your goods.

Just to throw this out there: my 600W dimmable water cooled setup is running about 380 dollars. Take into consideration the costs of the IC COB were 30$. The good thing about this is I can upgrade the LEDs for better ones down the road without loosing out on big lump sum investment. I'll be creating a thread once all the parts come in and I have time to build this beast.

An air cooled big heat sink setup will be considerably much less, mind you, if anyone chooses to budget their build. Either way you build an IC Cob, hands down 600W of LEDs will have a better light output and less heat than any 600W hps/mh setup.

 

[DIY-HP-LED]

Chinese full-spectrum lights are magenta in color and emit 380nm-840nm light with max peak output at 420nm and 640nm. And broad spectrum is the sunlight at high noon, which is around 5000K.


To clear things up, baoshengk did refund all my money, and I got to keep the 6 20W COBS. And my overall experience with him was pleasant and eBay is a safe place to buy your goods.

Just to throw this out there: my 600W dimmable water cooled setup is running about 380 dollars. Take into consideration the costs of the IC COB were 30$. The good thing about this is I can upgrade the LEDs for better ones down the road without loosing out on big lump sum investment. I'll be creating a thread once all the parts come in and I have time to build this beast.

An air cooled big heat sink setup will be considerably much less, mind you, if anyone chooses to budget their build. Either way you build an IC Cob, hands down 600W of LEDs will have a better light output and less heat than any 600W hps/mh setup.

I ordered 10 of the CW and 4 of the grow spectrum 110 volt 50 watt version. I have several air cooled fixtures (old microwave tower amps) that can handle 100 watts passively cooled with regular LEDs. I plan on putting about about a half dozen of these 50 watt AC COBs on a fixture with a 5" or 6" fan active for cooling. Say 4 CW and 2 GS per fixture (I have several), I'll use a three prong plug and make damn sure the fixture is properly grounded. This might just make a 600 watt HPS equivalent lamp for less than $20 bucks in COBs and fans.

Here are a couple of pictures of the fixture setup with 2x100watt LEDs in parallel with a 100 watt driver. It will run passively, but I added a fan for a bit of additional cooling, I plan on removing the PSU box and replacing it with a larger fan for extra cooling.

 

[ssj4jonathan]

I ordered 10 of the CW and 4 of the grow spectrum 110 volt 50 watt version... I plan on putting about about a half dozen of these 50 watt AC COBs on a fixture with a 5" or 6" fan active for cooling. Say 4 CW and 2 GS per fixture (I have several), I'll use a three prong plug and make damn sure the fixture is properly grounded. This might just make a 600 watt HPS equivalent...

You're on the right track! Your setup will be very similar to mine. 7 IC cobs in parallel will get you somewhere near 300 watts of actual LED power. Still not sure if you can run these IC cobs in series as each of the 5 parallel chips need 120VAC @ 80mA to give 48W for the LEDs? With two rigs you'll blow a 600 HPS out of the water. Start a new thread when you set this up. I'll be subbed for sure.

 

[ssj4jonathan]

For posterity's sake, here's a link to my 600 watt watercooled Smart IC Dimmable LED build:

https://www.rollitup.org/t/watercooled-smart-ic-cob-led-build.943904/#post-13626191

 

[DIY-HP-LED]

I got some 110 volt driverless COBs a few weeks back and I'm gonna test some on one of my air cooled fixtures soon. I was laying out the parts on the heatsink and found the mounting holes in the COBs mach up with the holes for the 100 watt floodlight LEDs, so it simplifies things a bit.

The lamp will be composed of a heatsink, 2 X CW 50 watt AC COBs, 1 X 50 watt full spectrum 50 watt COB, a 120mm 12 volt fan and a power supply module for the fan. Not sure If I'll bother with a switch, but a three prong grounded chord with a good ground on the heat sink is a must. I obtained the heatsink at the salvage yard, it's an old microwave amplifier housing used in microwave towers. After I stripped out the electronic guts and cleaning it up I found this foot long,15 LB chunk of aluminum to be a great fixture for a double LED 100 watt lamp with a 10" COB spacing. I have four of these heatsinks and I bought 10 CW and 4 full spectrum COBs, so if this works out, I'll have four 150 watt grow lights. Best of all the CW COBS cost less than $2 CDN each and the full spectrums were around $3 CDN each. Also I've got a couple of spare CW COBs.

Here are a couple of pics of the layout for a lamp, I hope to have it complete in a couple of days and will post more then.

 

[DIY-HP-LED]

110 Volt AC Driverless COB Lamp Test
I completed the 110 volt AC driverless COB lamp today, it was a one day build. I seems to draw 200 watts from the wall according to my Kill-o-meter (will have to check on that). The fixture runs at about 40C and the single COB light output appears to be about the same as a 32 volt DC floodlight COB running at 50 watts. It tested ok for grounding and there's no current leaking through the COB packages to the heat sink and the lamp is well grounded with a three prong plug. Now for some pictures.
I used a terminal block salvaged from a streetlamp to hook up the wires. On future builds I might just solder them together and cover with shrink tubing, then I can tuck them under a reflector, if I want to add one. I used gobs of silicone to hold down the wires and to hold the chord strain relief in firmly. For added safety I could put gobs of silicone on the soldered COB contacts too.

I could tape on some sheets of plastic to the top of the heatsink fins to increase cooling efficiency, but the lamp runs cool enough.

During bench testing the lamp ran at 40 C and appeared to draw 200 watts, the fan draws less than 3 watts. I need to look further into this.

You can see the flicker these COBs produce in this picture as horizontal lines and estimate the loss of light by measuring the width of the shadow band as compared to the lighted band. I've got the light on test over a plant for now and it produces about 50K LUX on the grid at a 12" distance, also the full spectrum (burple) COB might be throwing off the LUX readings.

 

[DIY-HP-LED]

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 43 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) 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.

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 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 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 better. It could be a way for some people to get somewhere better over time.

More info on my thread https://www.rollitup.org/t/economical-multi-led-chip-projects-for-growing.852256/page-16

 

[drspastic]

hi, just picked up on this thread. i haven't been here for a while. heres some photos of my latest water cooled bars. im using 220v cobs glued to ali extrusion with internal pipework to even the temperature. currently running as my central heating boiler. i have a few kw of these running in pink PAR, warm and cool white, and some reds. I have run these cobs for over a year and last week had the first failure. a pink one burnt out on a 450w bar because I kicked the pump plug out of the wall and never fitted thermal cutout to the early units. i now am making 1kw bars with all safety features. the system runs almost silent and is 100% efficient as the cooling water keeps my house warm for free! a top tip for diy lights is to get a thermal imaging camera and build a spectrometer.
before anyone takes the p**s about using soil, i dont smoke or sell, i grow for feminised seed stock. the weed itself gets burnt.

 

[1212ham]

220 Volts AC? I sure hope it is properly grounded! Please put silicone or something over those 220V solder joints! A ground fault interrupter would be a good idea.

 

[drspastic]

all exposed potential are siliconed. no earth on the system as we don't have a proper earth where i live, its all split from 3 phase and a bloody mess on the overhead poles. fortunately I am a MSc in electronic engineering and have been used to working live on 100kv+ systems. to be fair, you have to be really careless to get electrocuted and common sense should prevail. i might make a few of these bars and include earthing and inbuilt RCD in addition to current trip and thermostat and sling them on fleabay. trouble is many buyers there actually need that label that says 'do not eat, insert into body cavity, or give to children under 2 years'. installation also requires a bit of plumbing knowledge and a few burps of air before its ready to fire. i will never go back to discrete drivers now unless im running from off grid DC. these 220v cobs are a great solution at a dollar for 50w and at that price who cares about efficiency maybe the cree chips are a few percent better but at the end of the day there's no justification to pay such a price unless you're paying Norwegian rates for electricity. out here where I live electricity is ridiculously cheap possibly the cheapest in the world on top of that I also run a solar system of a few kw so it costs me nothing and I can run as much as I want. your mileage may vary. as always, if anyone wants the instructions to build these big waterblocks i will be happy to share.

 

[1212ham]

i might make a few of these bars and include earthing and inbuilt RCD in addition to current trip and thermostat and sling them on fleabay. trouble is many buyers there actually need that label that says 'do not eat, insert into body cavity, or give to children under 2 years'.

LOL. It sounds like you've had good reliability, do they run near room temperature? Any light measurements or efficiency data?

 

[Goerilla]

all exposed potential are siliconed. no earth on the system as we don't have a proper earth where i live, its all split from 3 phase and a bloody mess on the overhead poles. fortunately I am a MSc in electronic engineering and have been used to working live on 100kv+ systems. to be fair, you have to be really careless to get electrocuted and common sense should prevail. i might make a few of these bars and include earthing and inbuilt RCD in addition to current trip and thermostat and sling them on fleabay. trouble is many buyers there actually need that label that says 'do not eat, insert into body cavity, or give to children under 2 years'. installation also requires a bit of plumbing knowledge and a few burps of air before its ready to fire. i will never go back to discrete drivers now unless im running from off grid DC. these 220v cobs are a great solution at a dollar for 50w and at that price who cares about efficiency maybe the cree chips are a few percent better but at the end of the day there's no justification to pay such a price unless you're paying Norwegian rates for electricity. out here where I live electricity is ridiculously cheap possibly the cheapest in the world on top of that I also run a solar system of a few kw so it costs me nothing and I can run as much as I want. your mileage may vary. as always, if anyone wants the instructions to build these big waterblocks i will be happy to share.

I agree with you considering the efficiency but I have tried some 100W Chinese cobs with normal drivers and the plants did not grow very well under them, I found that when i exchanged 2 Chinese with one Citizen 1212 the plants were growing better.
I should make a proper side by side test to verify that but that has to come in the future.
Btv. The Citizen is a 3500K 90 cri.

Rilla.

 

[drspastic]

only measurements currently held are spectrum, but that holds no surprise. all as expected. par is spot on, warm and cool white are without much in the way of spurious peaks or troughs. reds do hit a good few nm above and below 670 to 630. i don't have a good light meter atm and they cost big bucks for a scientific useful one calibrated to all wavelengths.
i have some photographic ones and the one on my phone lol! i might try one on a black body calorimeter if i can get my vacuum pump fixed. that should be pretty accurate. as for running temperature, well being that i cool with the central heating loop, its exactly room temperature! leds read about 30c on the thermal imaging camera and ir thermometer when run up to temperature. key to good cooling is bore and flowrate. the little cpu waterblock that china sells is ok for small strings but after half dozen in series you have to start parallel connection with associated flow balancing issues. i get best results using 16 mm ali pipe flattened a little, feeding cold into the far end of extrusion thats blanked off, then hot return is a stub sealed next to the inlet. it stops hotspots. the cnc routed waterblocks people make are certainly works of art but unnecessary. you do need a good pump, and while the cpu waterblock can run on a tiny pond pump or even (!) a tiny dc pump running from a peltier TEG chip behind the led, its far from ideal and you have to choose your rads carefully to be effective at that miserable flowrate. a nice cheap DIY exchanger is a heater core from the car breakers yard, or oil cooler rad which comes with pipe sizes that push fit the 8mm cpu cooler pipe. best thing to do is get a cheap central heating pump. they are designed for continuous operation and variable flowrate. better than having a cheap plastic pump give up while you are out, come home to fire brigade and police.

 

[DIY-HP-LED]

18" Long x 1"x1" aluminum tube water cooled AC COB Lamp
Here is an 18" long 5x 50 watt 110AC COB water cooled light bar I built from some leftovers awhile back, the COBs are mounted with thermal paste onto a 1" square piece of aluminum tubing, the 1"x1" LES area is covered by the cooling tube and the COBs are cool to touch on the edges and only run a few degrees above the cooling tube. I use 3mm screws and nylon standoffs mounted on a piece of channel as a back plate. You can build water cooled lights from 1" x1" square aluminum tubing that costs about a buck a foot. Just slather a 7/8"pipe threaded brass, 1/2 PEX or hose barbed fitting with epoxy or silicone and screw it into the end of the aluminum tube, making sure to fill in the side corners of the tube.

SAFETY:
I used a three prong plug with this lamp and had a separate ground wire clamped to an earthed copper heating pipe, the lamp was double grounded. Running it through a GFI breaker receptacle would be a good idea as well. I also covered all AC power points with silicone rubber adhesive gobs. Even if you have to drive an iron rod one meter into the earth and run a ground wire to your grow, make sure your lamps are grounded. If ya fry, you'll be dead in yer grow a long time before anybody finds yer decaying body cause the carbon filter will take care of the smell.



A closer look at how I did this, I have a thermal cutoff switch on the line side incase the cooling system packs it in. Works great by the way and the COBs run cool. This 1" cooling tube design and mounting method works great for DC floodlight COBs as well as quality COBs that use a holder.



This is what she drew on the bench test after it was running for a bit and stabilized the draw. So according to these readings, each COB draws 59.6 watts x 5 = 298 watts

 

[drspastic]

nice build, those klixon cutouts are essential and very cheap. i use 75c because thats what i had a box full of. 50c is better. when that pump stops the temperature increases very fast. the cobs driver circuit does moderate thermal runaway with negative feedback but its not always enough as i learnt with my fried chip the other day. water cooling is the future and i am surprised so few manufacturers are getting in on it.