The dawn of COB LED's - Efficiency - Power supply & driver options - DIY?

G

Gree N

New Member
Hey guys I am reasonably new too these forums and very new too the whole subject of led cob's and there power supply. Mainly all I read in most diy cob builds is that you pretty much have no option but too run a meanwell hlg driver, considering my main power supply's are 240v- 60hz it's not the best option for me?

For experimental sake I've ordered non brand 50w and 100w cob led's which come with power supply's.
I have also ordered an extra five 50w non brand drivers 36v @ 1500ma which I was hoping too power five 55w Citizen cobs
420-magazine-mobile1635721089.jpg
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So obviously I've ran into a problem here, originally I thought great 36v & 50w would be perfect to run these chips "hard". And hopefully I can get 8-10k lumens. As I've been pointed out by another member here the cob although rated at 55w it can only take a max currant of 1380ma. The driver I've ordered will put out 1500ma/50watts at 36v.

So main question is, could I possibly run two cobs at 750ma running them in parallel. I'm aware of the thermal runaway but as I've read there are a few ways of avoiding this either with a buck converter or simply fuses. Would this be a possible option?
I've been to checkout a electrical & powersupply hobby type shop and had a good discussion about the possibility's of buck converters and the different option he could supply, he also suggested to order custom built transformers which can be made to any specification, anybody have experience with this route for diy driver builds? I'm assuming you could go as far as using resistors and buck converters to build your own custom driver?

Anyway I was just hoping for some advice on this situation and some good threads or diy builds suggested that don't take the conventional hlg setups.

Possibly if anyone would like to post there setups and power supply's with cost's. (of driver components).
 
Re: The dawn of cob led's - efficiency & power supply/driver options. DIY?

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Opinions on the best spectrum? Looks like the 4000k is a winner in 70 Cri or 80 cri?
 
The dawn of COB LED's - Efficiency - Power supply & driver options - DIY?

jimmyclone said:
No, tons of blue in there. 3500k is a full cycle spectrum .
Click to expand...

If I am understanding that chart there is a lot more blue in the 4000k and pretty much identical red
 
The deep red or far red is what is needed for flower. If i were you i would get equal chips half 80cri and half 90cri..So say 2 3500k 80cri and 2 3500k 90cri.. Im planning on swapping 2 2700k 90cri to the center of both my panels.. The reds are needed..
Check this chart out, look at how narrow the hps spectrum is and people have been using hps as a full cycle light for 30+ years..
420-magazine-mobile963386417.jpg
 
The Relative Quantum Yield curve has been adjusted for absorptance and represents the yield for light that was actually absorbed so this is not a good comparative model to use for actual light spectrum emitted and should not be used directly for grow light comparisons.

3. The values are relative to each other with the highest value arbitrarily set at 1 (100%). This does not mean that the wavelength at the value of 1 (100%) is absorbed and utilized for photosynthesis; only a small fraction of theradiated light is ultimately absorbed and effectively used in photosynthesis, even at the curves peak value.

radiated light is ultimately absorbed and effectively used in photosynthesis, even at the curves peak value.Curve would not be ideal, it probably is a relatively decent spectrum, but that is just circumstantial. This is a very common misconception about plant lighting which escapes many designers who try to match the McCree curve profile.

Having read this Im very keen to find out precisely which parts of the spectrum our old friend MJ photo's preferences are.
 
when it comes to red and far-red light as far as signals (not photosynthesis), it's not the amount as much as the ratio of red to far-red that's important to the plant! For the purposes of the plant and its response to light spectrum, red light is ~660nm and far-red light is ~730nm on the light color spectrum

In bright sunlight, a cannabis plant tends to grow short and squat. This is because direct sunlight usually has more red than far-red and the plant reacts to this ratio. So if a plant is getting more 660nm than 730nm light, the stems tend to stay short and the plant grows a lot of nodes with shorter stems.

On the flip side, if a plant is getting a more 730nm light than 660nm, it tends to grow tall and stretchy. This is because, in the wild, when a plant is surrounded by a lot of vegetation, the surrounding leaves absorb a lot of the red light, and so whatever light does filter down to the hidden plant or stem has a much higher ratio of far-red light.

In response to higher levels of far-red light, stems will start to elongate and grow taller, as the plant is "stretching" up towards the light until it gets a ratio with more red and "senses" it's in direct sunlight again.

If a plant is surrounded by greenery, it starts sensing higher ratios of far-red light, and starts "stretching" upwards to grow past the other vegetation and get access to better quality light
 
PAR actually considers only the spectral range of solar radiation from 400 to 700nm, which is the spectra of light that plants can use for photosynthesis.
 
Vero 29 3500 or 4000k mixed with Vero 29 1750k. The Vero 17k is the only chip with a 650nm power peak that tapers off to the 700nm range and into the near infra-red. In combination these are the two best COB chips on the market for veg and flower.
 
Gree N said:
Hey guys I am reasonably new too these forums and very new too the whole subject of led cob's and there power supply. Mainly all I read in most diy cob builds is that you pretty much have no option but too run a meanwell hlg driver, considering my main power supply's are 240v- 60hz it's not the best option for me?

For experimental sake I've ordered non brand 50w and 100w cob led's which come with power supply's.
I have also ordered an extra five 50w non brand drivers 36v @ 1500ma which I was hoping too power five 55w Citizen cobs
420-magazine-mobile1635721089.jpg
420-magazine-mobile1469605873.jpg


So obviously I've ran into a problem here, originally I thought great 36v & 50w would be perfect to run these chips "hard". And hopefully I can get 8-10k lumens. As I've been pointed out by another member here the cob although rated at 55w it can only take a max currant of 1380ma. The driver I've ordered will put out 1500ma/50watts at 36v.

So main question is, could I possibly run two cobs at 750ma running them in parallel. I'm aware of the thermal runaway but as I've read there are a few ways of avoiding this either with a buck converter or simply fuses. Would this be a possible option?
I've been to checkout a electrical & powersupply hobby type shop and had a good discussion about the possibility's of buck converters and the different option he could supply, he also suggested to order custom built transformers which can be made to any specification, anybody have experience with this route for diy driver builds? I'm assuming you could go as far as using resistors and buck converters to build your own custom driver?

Anyway I was just hoping for some advice on this situation and some good threads or diy builds suggested that don't take the conventional hlg setups.

Possibly if anyone would like to post there setups and power supply's with cost's. (of driver components).
Click to expand...

The reason everyone uses Meanwell is because they are designed for LED COBs. Their voltage output is in multiples of 36v That means you can fit the perfect amount on a driver at the right current. You need to occupy 90-95% of the available voltage to operate in constant current mode. Meanwell driver's do this perfectly. I've tried Fulham, Tridonic, GE and Phillips. Meanwell beats them all in price and quality. All Meanwell HLG C series drivers can operate at 240v.
 
Hi...Newbie here from South Africa. Agencies for lighting are thin on the ground and things are expensive. Seems most people are using HID's or a LED panel such as a Mars 1600. I have been researching for some time and want to build an organic coco/pots grow garden with veg and flowering. In my flowering rooms I want to use 4 footprints of 1.2 x 1.2 which I think is imperial to you guys 4 x 4. Reading up, I am convinced that the right long term way to go is LED instead of HID's.....I am keen on the COBs......Bridgelux Vero 29 and would like to do a DIY build aluminium frame for the 4 x 4 footprint.

I am thinking of 900/1000 watts over the 4x4 canopy. I want to "drench" the area with at least 800/900 umols PPFD. Thinking 5 x Vero 29 3500k 80 CE and 5 x Vero 29 3500k 90 CE. People talk about 50w 75w 100w chips.....looking at Vero array....I see family, kelvin, color temperature chip configuration and generation.......is it the size drivers that takes the chips to, for example 100w or 50 watt? Dimmer for a bit of flexibility. Sanlight (available here) makes some interesting fixtures and a Quantum board (needs to be imported) looks interesting to boost things.....but for the time being I am looking at sticking to a pure COB installation.....Vero 29 COBs.

I am very confused with the Meanwell driver selection.....series....parallel....not pushing driver but not under running...... at a later stage might want to add 2 x COBs taking the fixture to 12 units. If someone has the time, could someone comment/advise me in the right direction on the overall equipment needed to achieve what I am looking for.....chips, temp color, wattage, PPFD, drivers.

A comment that always comes up that I find intriguing.....but the forums don't seem to spend time emphasising on it, is that they say the higher the current draw the lower efficiency lumens....lower current draw better lumen efficiency......I assume this factor is an important issue when doing a design from scratch?
 

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