Fanleaf's Huge 42 COB Array Build Plus Other Builds

Ok so here's the info on the driver that I found it says 0-10 volt Dimming driver 700ma 75watts
Uni voltage . Other optic info LED's
Cri=70 for 4000k
IES Full Cutoff , No glare ,No light Trespass
So I understand very little can someone explain ? Should I buy a Cob or Cobs and scrap the light but keep the driver?


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cnile said:
Like if u could set up one Cree led at a certain distance at 50mA and measure lux at each corner and center. Then try at 75mA and 1A.

Is that asking too much.

I want to compare it to my 25 watt t5HO 2" for a real life comparison for figuring money.


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Click to expand...
Im glad to help you with this but first you need to understand where you are mistaking. Ma to ma test will tell tou ABSOLUTELY NOTHING. You need to test power each device is using. That is wattage. Watts is total power used. Milliamps will tell you absolutely nothing.
Please study "ohms law". That way you can do your test with any accuracy.

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@cnile
Maybe you will understand it this way. If one device is using 100mA and a different device is using 2000mA which one do you think is using more power???

The answer is, who knows? Nobody could answer that with only that info.Either one may be using more power then the other. It depends on more than just milliamps.


One device is using 100ma at 200 volts so its using 20 watts of total power.

Another device is using 2000ma at 10 volts and is also only using 20 watts of power!



My point is watts is what you are after.
 
all your coltages/ams will be fine cause i can just upscale or downscale. but what i want to know is,


if you have a lux meter or something.

so one COB.

what is voltage
what is amp

hang single cob at 12"

take reading at center and corners, 24" from center

then hang same cob at 36" and measure same 5 spots on lux meter.



thats all i realy want to know.



your saying more voltage push more current but i dont get why. these cobs and drivers are fixed voltage. they supply 36v to the cobs or 72v depending on the model that you buy.

the current is what is the variable, the cobs -36v or 72v - run at the constant voltage but vary greatly in efficiency and how many lumens it puts out depending on the amps you run through them.


so with your 36v cree cob you can buy driver
1. 36v driver 1.0 amp
2. 36v driver 1.5 amp
3 36v driver 3.0 amp

and each one would have different readings for the test im saying and different watts of course. the watts would be simple to figure, just ohms law.

taking those readings then you can find watts per lumen for your single cob at the different amps


does that explain what im trying to figure here at all better?
 
livetoskate81 said:
Ok so here's the info on the driver that I found it says 0-10 volt Dimming driver 700ma 75watts
Uni voltage . Other optic info LED's
Cri=70 for 4000k
IES Full Cutoff , No glare ,No light Trespass
So I understand very little can someone explain ? Should I buy a Cob or Cobs and scrap the light but keep the driver?
Sent from my iPhone using 420 Magazine Mobile App
Click to expand...


Ok, so if I'm calculating correctly your driver should be capable of 107 volts DC@700 milliamps. You would for sure want to go with 2 50volt cobs in series. Let me see what they would do for you at 700mA....Be back soon
 
fanleaf said:
Ok, so if I'm calculating correctly your driver should be capable of 107 volts DC@700 milliamps. You would for sure want to go with 2 50volt cobs in series. Let me see what they would do for you at 700mA....Be back soon
Click to expand...

Thank you so very much I just want to get rid of the big 250 cfl and the homemade 800watt cfl hood they work great for Veg but Flower they just don't cut it and I have to monitor the lights all the time always adjusting and moving plants around !!! Live-Love-Learn


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cnile said:
your saying more voltage push more current but i dont get why. these cobs and drivers are fixed voltage. they supply 36v to the cobs or 72v depending on the model that you buy.

the current is what is the variable, the cobs -36v or 72v - run at the constant voltage but vary greatly in efficiency and how many lumens it puts out depending on the amps you run through them.


so with your 36v cree cob you can buy driver
1. 36v driver 1.0 amp
2. 36v driver 1.5 amp
3 36v driver 3.0 amp

and each one would have different readings for the test im saying and different watts of course. the watts would be simple to figure, just ohms law.

taking those readings then you can find watts per lumen for your single cob at the different amps


does that explain what im trying to figure here at all better?
Click to expand...

No, your wrong bro.

cnile said:
so with your 36v cree cob you can buy driver
1. 36v driver 1.0 amp
2. 36v driver 1.5 amp
3 36v driver 3.0 amp
Click to expand...

1. NOTHING NOTHING NOTHING is fixed voltage.
2. Heres the deal man. Let's take a Cree CXB3590 for instance.
At 2100mA it will run at 36 volts period ok? Now if we have a driver that tops out at 36 volt but can provide 3000ma and hook that same cob up to that driver it will still only use 2100ma! Why? simple...because at 36 volts that cob pulls 2100ma! It wont use the 3000ma the driver can provide because the driver tops out at 36 volts and at 36 volts the cob only pulls 2100ma. AGAIN BRO.....VOLTAGE PUSHES CURRENT! This is not up for discussion it is OHMS LAW! If we want that same cob to run at that 3000ma then we need to find a driver that can provide a higher voltage than 36 volts period. That same cob may be able to draw that 3000ma but it may need 38 volts to do so.

Lets make this very easy;
Lets say you have a cell phone charger and 2 cell phones
Phone 1 says it needs a 3.7 V charger @1000ma.
Phone 2 says it needs a 3.7 V charger @2000ma.

The only charger you have says 3.7 volts @ 50,000ma!
Would you plug either of your phones into that 50,000ma charger????

The answer is YES!!! Reason is because its a 3.7 volt charger. The phone will only suck in as many milliamps as it needs to charge!!!!!
With that charger phone 1 will charge at 3.7 volts and 1000ma.
Phone 2 will charge at 3.7 volts and 2000ma! Its only the difference in resistance in the phones man.

Do you follow???

A device will only use as much amperage or milliamps as it needs!
 
cnile said:
so with your 36v cree cob you can buy driver
1. 36v driver 1.0 amp
2. 36v driver 1.5 amp
3 36v driver 3.0 amp

and each one would have different readings for the test im saying and different watts of course. the watts would be simple to figure, just ohms law.
Click to expand...

#1 shown above is wrong because @ 1.0 ams the COB WILL NOT PULL 36 volts!!! It will only run at maybe 33 volts at 1.0 amp.

#2 is wrong for the same exact reason #1 is wrong for. At 1.5 amps that 36 volt chip will only pull maybe 35 volts

Number 3 is wrong because at 36 volts the COB WILL ONLY PULL 2.1 amps period.

If you wanted that chip to run at 3.0 amps it may need 37.7 volts.
 
livetoskate81 said:
Thank you so very much I just want to get rid of the big 250 cfl and the homemade 800watt cfl hood they work great for Veg but Flower they just don't cut it and I have to monitor the lights all the time always adjusting and moving plants around !!! Live-Love-Learn


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Click to expand...


Do you have a multimeter? to test voltage?
 
livetoskate81 said:
Yes fluke meter


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Perfect. Nice meter! I love my Fluke.

So I know exactly what your options are we need a simple test. Disconnect the + and - leads of the driver from the LED's. Hook up your Fluke to the driver leads and power the driver up. Let me know the highest voltage reading. Be sure your meter is in DC mode. The led's must have at least one leg disconnected from the driver either the + or the - for the driver to show us it's high voltage.
If you can that would take all guessing out of the game and we can set you up with a few cobs that we know will work perfectly with it.
Obviously hook up your leads then power it on. Any DC over 50-60 volts will shock you.
 
Here Cnile
Here is a datasheet for a Vero29 Chip. Do you see what I mean now!!!
This is a 52 volt chip!
At 900ma it runs at 49.6 volts.
At 1200ma it needs 50.5 volts
At 1800ma it needs at least 52.0 volts to be able to push 1800ma through it.
If you want to push 3600ma through it IT MUST RUN AT 55.8 volts!!!
vero_example.JPG
 
fanleaf said:
Here Cnile
Here is a datasheet for a Vero29 Chip. Do you see what I mean now!!!
This is a 52 volt chip!
At 900ma it runs at 49.6 volts.
At 1200ma it needs 50.5 volts
At 1800ma it needs at least 52.0 volts to be able to push 1800ma through it.
If you want to push 3600ma through it IT MUST RUN AT 55.8 volts!!!
vero_example.JPG
Click to expand...

lets forget everything we talked about so far.

how about this question



regarding the 3590 cobs from cree---

there are the two chips, one 36v and one 72v

now cree lists this two chips at these two voltages for a reason i assume. either its where they best perform or its the voltage that the cob is made to run at. do you know why cree has two different voltage cobs
 
cnile said:
lets forget everything we talked about so far.

how about this question



regarding the 3590 cobs from cree---

there are the two chips, one 36v and one 72v

now cree lists this two chips at these two voltages for a reason i assume. either its where they best perform or its the voltage that the cob is made to run at. do you know why cree has two different voltage cobs
Click to expand...

They are listed as a 36v chip because that's in about the middle of what they are capable of. At 36V they pull 2.1 amps and that =75.6 Watts. The 3590 is not a 75 watt chip it is a 138 watt chip. At 138 watts it runs at 38.5 volts at 3.6 amps.

They have a 36v chip and a 72 volt chip so it's easy to find different driver combinations. If you have a driver that is capable of 160v but only 1000ma then you would for sure want to run the 72 volt chips if you wanted to run only 2 chips. The 72 volt chips run at twice the voltage but half the amperage. So with 2 chips in series you have 144 volts right? Your driver is capable of 160 volts at 1000ma. So now we know that driver will run 2 chips at 1000ma so you will have a 144 watt light.

If we ran the 36v chips on that driver they need twice the amperage but half the voltage AND OUR 36 VOLT CHIP ONLY RUNS AT 33 VOLTS AT WHAT IS NOW A MEASLY 1000MA So take our 160 volt driver and divide by 33 volts which =4.88 cobs. So we can run 4 cobs on it but only at 1000ma for a total of a 132 watts

The 2 different voltages just give more driver options for the most part.
 
cnile said:
thanks



what im getting at here is put resistors in (based on specific setup - heat production & specific cob's resistance) to make this cob run at voltage it is supposed to be.
Click to expand...

:lot-o-toke:
Why bro? Do you know how big of a power resistor you would probably have to buy? Why not just buy a variable voltage power supply? They are cheaper than any driver we use to make these lights by far. And then your not burning up a damn huge bleeder resistor. Variable voltage power supply is probably cheaper then the power resistor you would need lol.

Let me say this, From the start your test is hugely flawed. How are you going to test lumens vs lumens on a 4 foot long tube vs a round cob light? You cant! You need a sphere to test that evenly. Unless you have a few hundred thousand laying around that isnnt gonna happen. Besides, lumens is based off a very flawed 555nm green center.
To be honest I don't have a clue why you would feel the need to see which one is more efficient. A freaking COB LED vs a T5HO? Seriously? Sorry man but Cobs are already proven to be more efficient than Double Ended HPS by far!
Dont take this the wrong way but we may as well be testing efficiency between a candle and the sun. Theres simply no comparison.:Namaste:
 
cnile said:
thanks



what im getting at here is put resistors in (based on specific setup - heat production & specific cob's resistance) to make this cob run at voltage it is supposed to be.

and

set my amperage (buy fixed current driver) based on whatever those tests i asked about show is a resonable compromise for spread/lumens to watt
Click to expand...

Oh my god. I've heard of this before. A device that allows you to manipulate the current and voltage to a COB right?
I think it's called a dimmer and it's included in every Meanwell HLG-C series driver.



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