DiY LEDs - How to Power Them

RandomHero8913 said:

Thats a constant voltage driver. You can add all the COBs you want, just divide 3 by the number of COBs you choose and that's your current.

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does that mean if the COB is rated at 3 amps that if i have a 3amp driver and i have two cobs connected to it that they will each receive 1.5 amps? Doesnt that mean they will run dimmer than normal?

That means each one will run more efficiently, giving you more light for the same 3 amps.

weirdingway said:

does that mean if the COB is rated at 3 amps that if i have a 3amp driver and i have two cobs connected to it that they will each receive 1.5 amps? Doesnt that mean they will run dimmer than normal?

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Yes and Yes. Two is probably the minimum you should run. The COBs may be rated for 3A but I doubt that is what the manufacturer recommends you run them at. The recommended current is usually around half the max amp. So in your case 1.5 which put you at 2 COBs.

nevergoodenuf said:

That means each one will run more efficiently, giving you more light for the same 3 amps.

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i feel so retarded when it comes to this stuff. Sorry but could you explain how that works? If its constant voltage i understand that each COB will get close to 100 watts/ or 36 volts, am i correct? How does that affect how many amps will be going to each COB?

and what is the best wiring for these, series or parallel and how would that affect how the lights operate?

i was REALLY close to buying a cheap premade light with like 100 3 watt LEDs or something on that order....but then i started learning about the actual power DRAW and that even though its advertised as a 300 watt grow light they in fact draw maybe half that so youre only getting maybe 150-180 TRUE watts.....and thats why i decided to go with a DIY arrangement because i read that you have a better chance of getting closer to 100 percent actual usage potential from the LEDs rather than under volting them by almost half.

Am i wrong in my understanding so far? Do you think i will have better results per watt with a DIY setup like im planning than buying a premade rig rated at the same wattage?

Stay away from any light that misrepresents there wattage. Those red/blue panels are garbage. All LEDS have a max power they can handle before they fry. They are going off of that max even though they are only running them at half. As you run an LED softer it will produce more light per watt. That is why we run a 200W COB Led at under 100watts. This chart will show you how the efficiency goes up as the wattage goes down.

Constant Voltage drivers mean that they are putting out 30-36v all the time no matter how many COBs you attach to them. Constant Voltage drivers are almost always wired to COBs usually a parallel circuit. So what comes next is the 3A. These 3amps are all the current you have. If you wire:
1 COB = 3A
2 COBs = 1.5A
3 COBs = 1A
4 COBs = .75A and so on...

The reason for running COBs at lower than max rated current is you gain lumens per watt, so LED efficiency is going up, you can position your lights around your plants instead of your plants around your light. Basically your aiming to get efficient distribution of light on your canopy.

nevergoodenuf said:

Stay away from any light that misrepresents there wattage. Those red/blue panels are garbage. All LEDS have a max power they can handle before they fry. They are going off of that max even though they are only running them at half. As you run an LED softer it will produce more light per watt. That is why we run a 200W COB Led at under 100watts. This chart will show you how the efficiency goes up as the wattage goes down.View attachment 3924740

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i really appreciate everyone thats chimed in so far...i have been doing a fair amount of reading and watching on youtube and so far i havent really found any bone headed explanations for bone heads like myself....

ok so nevergoodenough...if its best to undervolt these does that mean i shouldnt have bought a 100w driver but maybe a 50 to 80 watt one? or is there another way to undervolt them like with a resistor or something?

You would run them in parallel (positive to positive and negative to negative). When you run in parallel, the voltage will stay the same and it will split the amps between the 2. When you run in series (positive to negative to positive to negative) the voltage is X the number of COBs (2 COBs in series 70v)

nevergoodenuf said:

You would run them in parallel (positive to positive and negative to negative). When you run in parallel, the voltage will stay the same and it will split the amps between the 2. When you run in series (positive to negative to positive to negative) the voltage is X the number of COBs (2 COBs in series 70v)

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thank you very much. I have actually been waiting until i get these to put my girls into flower so im pretty anxious but also want to get it right.

Unfortunately probably because these are chinese LEDs i cannot find what the lumen output is but at 100 watts for fullspectrum would it be reasonable to expect them to be close to half of a warm white? so maybe 4000-5000lumens each?

If you haven't ordered them yet, don't. I look at some of the sellers on this forum for DIY kits. You will be much happier and the price is usually very close in price. With quality COBs you can expect over a gram per watt, but with cheap led you might only get around .7 grams per watt.

nevergoodenuf said:

If you haven't ordered them yet, don't. I look at some of the sellers on this forum for DIY kits. You will be much happier and the price is usually very close in price. With quality COBs you can expect over a gram per watt, but with cheap led you might only get around .7 grams per watt.

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well the order is a done deal....paid 31 USD for two of them and 25 USD for the driver......

i figure its a learning experience so as long as they light up at all and give out a decent amount of light ill be happy with the learning aspect

other than that....what outlets of parts do you recommend? for my next purchase assuming this one goes well ill feel more confident spending more

25$ for driver .which u got and where

Hey guys first post I'm looking at building my first COB and was wondering if anyone could tell me if my build is compatible? Two Vero 29 gen 7 C bin 69v @700ma with a meanwell Elg-100-c700a driver and a couple of Moduled Xtra 9980-C heatsinks that dissipates 49w. Thanks in advance.

justfuket said:

Hey guys first post I'm looking at building my first COB and was wondering if anyone could tell me if my build is compatible? Two Vero 29 gen 7 C bin 69v @700ma with a meanwell Elg-100-c700a driver and a couple of Moduled Xtra 9980-C heatsinks that dissipates 49w. Thanks in advance.

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Based on what I see in the specs, the driver should work just fine. I would think that if the sink can dissipate 49w then I would assume they should be fine. Have fun

I know that this barely squeezes into this thread topic, but the new to LED and what to buy thread is locked for months, so...

1st question...

Does anyone know of any good 15a fused c14 switches and where to get them? I watched the mou5 vids as well as a bunch of other reading that let me to these:
(cant post links) mazon com/Inlet-Power-Socket-Switch-IEC320/dp/B00511QVVK
but cannot find anything in range in 15a that is actually rated for that draw and has that large of a fuse.

Reason for wanting is i plan on building a box style light (guy I'm building for wont bend on this) that runs power through a 15a inlet with neutral to 3 meanwell hlg-240h-54a/1 meanwell fan driver, hot to 4 switches (3 which are light zone control and one for fans) then to driver.

Wanting to protect entire unit from surge so figured its either run 15a which should cover the rated amp draw of 4 on each driver, or have to run (3) 5a inlets and 3 cords which will look ugly as sin and lower my chance of building more. That said maybe these don't actually draw 4a each and I'm overthinking this?


2nd question...

With the 350mVp-p noise coming from each 240h-54a I can assume is additive like in HID? Really don't know much about all of this tbh (I build the computers and did AC/heating work for this guy and is now giving me a shot at this) but one of the things he he had complained about was the money he had to spend filtering his other lighting (legal caregiver grow, but cable company threatened to shut off service or some such) so will I need to include some noise reduction in the wiring?

If yes to the above... Is there a good thread someone can point me too or give me a bit of help understanding what is required for reduction of noise generated by powering the LEDs? Most everything I can find n the subject is on HID lighting and using ferrite beads/toroids (some designs in conjunction with a couple .01uf caps for input side) but I'm guessing these drivers put out a bit different noise so unsure if this will isolate any issues.

Sorry this isn't exactly on powering the LEDs, but more on the challenges accompanying the powering of LEDs. Any help or guidance to where to seek this info/parts would be great though. I'm actually a bit shocked on how few threads/resources there are that deal with the noise issue especially as there are so many dealing with it in the HID threads, anyone with a good amount of electrical know how there could probably make a sorely lacking thread that covers an issue that doesn't seem to be talked about much.

Thanks in advance.

BloodKil said:

With the 350mVp-p noise coming from each 240h-54a

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The Ripple and Noise refers to the quality of the DC not radiated or conducted EMI noise. You should not need any filtering.

Need some help guys picking a driver. Last build I used HLG-185H-C1400B per 4 cobs but I want to use a bigger driver this time.

What should I use for 4 vero29 gen7 cobs i think they are D bin bought them from rapidled -
Mean Well HLG-240H-C1050B
Mean Well HLG-240H-C1400B
Mean Well HLG-320H-C1400B
Mean Well HLG-320H-C2100B

Here's what I bought

NorthernEmeraldNursery said:

Need some help guys picking a driver. Last build I used HLG-185H-C1400B per 4 cobs but I want to use a bigger driver this time.

What should I use for 4 vero29 gen7 cobs i think they are D bin bought them from rapidled -
Mean Well HLG-240H-C1050B
Mean Well HLG-240H-C1400B
Mean Well HLG-320H-C1400B
Mean Well HLG-320H-C2100B

Here's what I bought
View attachment 3930174

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I run the same arrays. What I think that you need to decide is how hard your going to drive the arrays. The D is spec'd at 2100mA but you can get better efficacy at lower mA's...but you also get lower actual photon output so you need more arrays to equal what you get at the higher drive current.
My setup uses the 320H-C2100B driver.works very well and allows me to run at lower forward current when I don't need the lumens.

GBAUTO said:

I run the same arrays. What I think that you need to decide is how hard your going to drive the arrays. The D is spec'd at 2100mA but you can get better efficacy at lower mA's...but you also get lower actual photon output so you need more arrays to equal what you get at the higher drive current.
My setup uses the 320H-C2100B driver.works very well and allows me to run at lower forward current when I don't need the lumens.

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I want to run at 50w but be able to run up to 75w so I'm thinking of going 320h-c2100b and run a 100k pot.

I would like to mix 80 and 90 cri of clu048 1212 3500k,parallel wiring.It is possible or it is better to avoid mixing different cri cob?