LED FAQ) Building and DIY

[Dion]

So, if I built 3 COBs like that, would that be sufficient for the 16"x24" space? What mistakes am I making?

Thanks!

no mistakes but you can do better

that is a cxa z2 bin(40 euro?)

use this one instead

http://www.digikey.com/product-sear...1&stock=1&quantity=0&ptm=0&fid=0&pageSize=500

much better and same price


for the driver try

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2189302_-1

dimmable more efficient and can run 4

or

http://www.sager.com/hlg-120h-c1400-a-4644966.html


dimmable cheaper and more efficient can run 3


also get

http://www.newark.com/ideal/50-2303cr/led-holder-cree-cxa35-cob-array/dp/39X0077

and you need a thermal grease like
http://www.digikey.com/product-detail/en/120-SA/345-1006-ND/340304

and self tapping screws like
http://www.digikey.com/product-detail/en/PSMS 004 0038 PH/H800-ND/333049

 

[jesbuds]

Dion, I don't really understand the driver recommendations. Wouldn't running 4 3070's in series mean each gets 1.4a but you'd be overdriving the driver (~210w and ~149v for LEDs). In parallel you're only giving each LED 350ma and then running the driver below specs (~38v). Just trying to understand the how for myself and such.

 

[jesbuds]

I'm high, the undervolting was a silly thing to bring up at all.

 

[TexMex McDirt]

If you use a single driver to power multiple COBs, how do you wire them? Series or Parallel?

 

[Dion]

If you use a single driver to power multiple COBs, how do you wire them? Series or Parallel?

in the examples i gave series

 

[Buddah Watcha]

TexMex, my cab is about the same size as yours, around 14"x26" and I'm running 2 CXB3070s @ 37w each, I could easily run a bit harder them without overheating the cab... but they seems to be doing the job pretty good, haven't ran a full cycle in this setup yet, however, plants seem to be enjoying! You can check the thread in my sig for more info! Cobs usually around 4-8" above plants!

Peace! BW

 

[ivan2015]

Hi to all you again , i have i question ;
I'm on the way for buy the COB's and Drivers , i need 76v more or less in output @1400mA , is better a driver with Output range for example 40-80v , or 70-120v ?
I think i'll buy the driver dimmable with dimm+- wires and a potentiometer.
Ty

 

[Sforza]

cree cobs require cob holders for mounting and for electrical connection

Good answers for most of the questions, dion, but you do not HAVE to use COB holders with Cree COBs.

SupraSPL has shown lots of photos of his lights that he builds with Cree CXB3590 COBs using kapton tape to hold down the COB to the heatsink and he solders the wires to the contact points on the COBs.

I use the holders when I build lights using Cree CXB3590 COBs because I like the way they hold the COBs tight to the heatsink and not having to solder the wire leads, but I have used the kapton tape to hold down other types of COBs and it works just fine.

 

[TexMex McDirt]

Hey BW. What driver are you using? How do you adjust the watts? Is that native to dimmable drivers or do you need to add a potentiometer? Or is that wattage just due to the type of driver you're using? This shit makes my head hurt. I should probably just go with a 150 hps and save myself the headaches.

 

[Sforza]

Hi to all you again , i have i question ;
I'm on the way for buy the COB's and Drivers , i need 76v more or less in output @1400mA , is better a driver with Output range for example 40-80v , or 70-120v ?
I think i'll buy the driver dimmable with dimm+- wires and a potentiometer.
Ty

Either one of those drivers with those voltage ranges would work fine, since the driver will provide the correct amount of voltage for the COB, as long as the driver is capable of providing the required voltage. Both of your examples can provide enough voltage to do the job, so you should probably buy the less expensive driver.

 

[Buddah Watcha]

Hey BW. What driver are you using? How do you adjust the watts? Is that native to dimmable drivers or do you need to add a potentiometer? Or is that wattage just due to the type of driver you're using? This shit makes my head hurt. I should probably just go with a 150 hps and save myself the headaches.

Hey bro, I use a HLN-180H-42b its dimmable, which I intended to use, but Im kinda of a newb too at this stuff, but its not too complicated after a bit of reading...

I just connected both cobs in parallel. The driver its rated 1.95amp, so divided by 2 cobs, thats around .95amp per driver @ 36v = 37w each cob. W = Amp x Voltage.

U can check the Cree website to know exactly which voltage the cobs run at depending on the amperage u kick into it.

I think running them at 1.2amp or even 1.5amp should be pretty safe too!

But like a said things are going great running them fairly low wattage (they run way more efficiently at lower wattages). In 2 months I should have a harvest and some numbers to know how good these run

Hope this helps!

BW!

 

[Sforza]

Hey BW. What driver are you using? How do you adjust the watts? Is that native to dimmable drivers or do you need to add a potentiometer? Or is that wattage just due to the type of driver you're using? This shit makes my head hurt. I should probably just go with a 150 hps and save myself the headaches.

I know how you are feeling, Tex. I was in the same boat about a year ago. Shit seemed confusing as hell. Everyone on the forums I was reading were using all sorts of lingo that did not make any sense at all to me. I would read the data sheets on the drivers and COBs and it was all Greek to me. But there is just a learning curve that you have to work your way through.

Let face it, with a 16”x 24” space, you are not going to break the bank buying the wrong type of COB or driver. Once you buy a driver, a COB or two, and a heatsink and fan, and start to put your hands on the equipment and see how it works, it is not rocket science, far from it. You hook the wires up and light comes out. The plants love the lights.

Google a guy who uses the handle SupraSPL. I found him to be by far the most knowledgeable and helpful poster on the subject of DIY LEDs.

He is both a hands on guy and he can and does do the math. All kinds of guys are always asking him what drivers and COBs they should buy for their situation. He makes lots of good recommendations and explains why he makes the explanations. I suggest reading a bunch of his posts and either asking him what you need or just following his recommendation to someone else who asks about a set up that is close to what you are planning to do.

You do not need to understand all the ins and outs of bins and CRI in order to put a nice little light together that is very efficient and that will last for a very long time.

 

[Sforza]

Hey bro, I use a HLN-180H-42b its dimmable, which I intended to use, but Im kinda of a newb too at this stuff, but its not too complicated after a bit of reading...

I just connected both cobs in parallel.

COBs should be connected in series.

 

[Sforza]

If you use a single driver to power multiple COBs, how do you wire them? Series or Parallel?

You always run them in series. If you are running four COBs that require 72 Volts, you would need a driver that can supply 288 volts. You add up the voltage of each of the COBs you are using and make sure that your driver can supply more volts than the required amount. For the best efficiency, you want to run close to the total amount of volts provided by the driver, but it OK to have a little slack so that the driver is not working so hard.

It is possible to run COBs in parallel, but it can cause problems, so it is not recommended.

 

[Chloemobile]

What problems are you talking about? I see many people running COB's in parallel.

 

[TexMex McDirt]

I know how you are feeling, Tex. I was in the same boat about a year ago. Shit seemed confusing as hell. Everyone on the forums I was reading were using all sorts of lingo that did not make any sense at all to me. I would read the data sheets on the drivers and COBs and it was all Greek to me. But there is just a learning curve that you have to work your way through.

Let face it, with a 16”x 24” space, you are not going to break the bank buying the wrong type of COB or driver. Once you buy a driver, a COB or two, and a heatsink and fan, and start to put your hands on the equipment and see how it works, it is not rocket science, far from it. You hook the wires up and light comes out. The plants love the lights.

Google a guy who uses the handle SupraSPL. I found him to be by far the most knowledgeable and helpful poster on the subject of DIY LEDs.

He is both a hands on guy and he can and does do the math. All kinds of guys are always asking him what drivers and COBs they should buy for their situation. He makes lots of good recommendations and explains why he makes the explanations. I suggest reading a bunch of his posts and either asking him what you need or just following his recommendation to someone else who asks about a set up that is close to what you are planning to do.

You do not need to understand all the ins and outs of bins and CRI in order to put a nice little light together that is very efficient and that will last for a very long time.

Hey Sforza, thanks for the advice. I have read a lot of Supra's stuff on RIU. He does know his shit. I wish I understood electrical stuff better. When it gets really technical I get lost. But, I'm not giving up. I am going to build out a new space and a new flower cab. My lighting will either be COB LEDs or a 150W hps. I feel like COB LEDs are the future and I want to get on board. We'll see. I really appreciate everyone's feedback.

Cheers!
Tex

 

[positivity]

Hit supra up on his thread and im sure he'll break it down better than anyone.

I take a more simplistic approach...i just build them and move on. Don't really look at every possible option or look for peak efficiency. Just a different style.

Normally i wouldn't recommend parallel but for such a small space it would let you use a low voltage driver which is why i brought it up. Running more than one cob in series puts you straight into high voltage territory.

I wouldn't recommend a parallel build with a more powerful system. Where if one led goes out the other leds would be overwhelmed quickly with too high a current and you start needing current mirrors and such. On a 1.6a driver a 3070 will easily handle that. Any voltage differences on such a lightly driven cob would be minute i'd guess

Id just get a arctic 11 cpu cooler, a 3070 cob, 1.4a driver, 5v-12v dc power supply, thermal adhesive (yes thermal adhesive) and glue that bugger to the heatsink.

Connect driver, cob, and fan power and go.

Save the parallel, slab heatsinks, and engineering masterpieces for another day. Just my 2c...

 

[Dion]

COBs should be connected in series.

no- his driver is 1.95mA below the max for his cobs

You always run them in series. If you are running four COBs that require 72 Volts, you would need a driver that can supply 288 volts. You add up the voltage of each of the COBs you are using and make sure that your driver can supply more volts than the required amount. For the best efficiency, you want to run close to the total amount of volts provided by the driver, but it OK to have a little slack so that the driver is not working so hard.

It is possible to run COBs in parallel, but it can cause problems, so it is not recommended.

its fine to run cobs in parallel but you have to measure the voltage and calculate the current correctly and plan for failure

why r u giving advise about stuff u dont know?

 

[Dion]

I meant to not use it with led drivers that are constant current. for fans it's ok. you have a 12V power source connected on the input and fans connected in paralel on the output. simple to set up.

@Dion, most pc fans (8 to 12 cm size) need 100-350 mA, so 1500 mA are nowhere near 20-30 fans. It's better to just read the power consumption on the fans (sometimes you need to google the model to find out, but most of the times it's written on the center of the fan, on one of the sides), and look for the mA or A rating.
From there you just add the mA of the fans, if you got more than one and you get a power source that can run a bit over that current.

let's say you got 2 fans that draw 150mA each, that equals 300 mA or 0.3 A (1000 mA = 1 A). You need a 0.5 A (500 mA) power source for that. The extra is there because you don't want to run psu's at full power and to allow for the dimmer draw (~100 mA) if you decide to use one.

@ dion, in my experience those shitty wall plug variable transformers are never good for their rated voltages, like sometimes 3 V is 5 V, 9 V is 12 V and 12 V is 18 V and so on. This is why I stopped using them and i'm using only regulated (stabilised) power supplies. That being said, have you checked yours with a multimeter?

well most fans are rated at .25A @ 12v-we run them at 5v(less than half power)

so a 1500mA driver thing can run 30 min as I stated

you must have bought shitty ones because all mine are within specs

however them being rated accurately is irrelevant here because we just want to adjust the fan power to as low as possible while cooling the sink so if it says 6v but its actually 7v no fucks given by me

perhaps you should revisit the 1st few posts of this thread where i talk about drivers- the same principles apply to fans as leds just they have dif requirements in the current and voltage department

 

[Dion]

Good answers for most of the questions, dion, but you do not HAVE to use COB holders with Cree COBs.

SupraSPL has shown lots of photos of his lights that he builds with Cree CXB3590 COBs using kapton tape to hold down the COB to the heatsink and he solders the wires to the contact points on the COBs.

I use the holders when I build lights using Cree CXB3590 COBs because I like the way they hold the COBs tight to the heatsink and not having to solder the wire leads, but I have used the kapton tape to hold down other types of COBs and it works just fine.

of course not but noobs dont like to solder

lol

@tex did you see this

https://www.icmag.com/ic/showpost.php?p=7254505&postcount=561