DiY LEDs - How to Power Them

Mary's Confidant said:
@Randomblame and others, I have 20 Bridgelux 1ft strips and 6 - 2 footers and I have an HLG 185H-C1050A and HLG 185H-C1400A to try and build something suitable for the cabinet in this thread:

https://www.rollitup.org/t/new-cabinet-build.968904/page-2#post-14377145 There are some major height restrictions and about 4 sq. ft.
Click to expand...


Hmm! For only 4sft you need only one of these 200w drivers and you already get 50w/sft. That's a lot! Probably +1000μMol/s/m². Do you want to use all the strips to make it as efficient as possible or do you need a few for a second veg area? You could use the HLG-185H-C1050 and 18 1footers in 9s2p(2x 9 strips in series connected in parallel). Each strip would run at 20v/525mA and you still don't need heatsinks. Only a frame, u-channels or alu flashing/alu sheet to mount the strips on.

It's not so easy to use both typs of strips on the same driver because they both have the same voltage but different currents. Diodes on 2ft strips would run with half the current compared to the diodes on 1ft strips when connected in series. You need to use 2 1ft strips in parallel connected to one 2ft strip in series to get even brightness. A circuit could look like this:
Screenshot_20180724-102005.png

But it's a lot of wiring effort because the strips would be mounted in a different way and you need a lot of wires to create the circuit.

18x 1 foot strips in 9s2p is a lot easier and you can use the 2 footers for another light/project.

Hate to say that but if you would have asked earlier... you could have ordered two HLG-100H-20A or B's for parallel connections. One for the 12x 1ft strips and the 2nd driver for 6x 2ft strips.
Is it possible to send them back and choose other drivers? 400w is anyway much to much. For 4ft² you could get away with only 150w (37,5w/sft)and still get ~750-800μMol/s/m². Maybe two HLG-80H-CxxxB would be already sufficient, one with 350mA(10x 1ft strips in series) and one with 700mA (5x 2ft. strips in series). Would be ~180w and an HLG-80 costs only 35$, HLG-100H-20A probably 36$.
 
Thanks @Randomblame, I'd rather just stick with the 18x1 ft strips. I'm not looking to overpower the space, i don't even want to push the limits. I just want a well lit growbox that'll produce quality medicine for me. 9s2p - meaning directly from the driver I'll split into two distinct lines and run 9 in series on each line, correct? So I'll use a 3 port wago for positive and negative and between the two addition ports, I'll run 9 in series/daisy-chained together.

Then I need some U channels for passive heatsink?

Is 525mA too high for that sized box? Would it be better to run the 185H-1400 in a 6s3p and arrive at 467mA per strip? I don't want heat headaches in this box, I'm looking for the sweet spot in terms of efficiency and quality meds.
 
Yepp, the wiring is correct.
But with heat it's a bit different. 200w are 200w!
Light is also a form of heat and gets converted when it hits a surface. For this reason light feels warm. So from this point of view it doesn't matters which driver you use. More efficient means more energy is converted into light and less direct heat will be produced. But in the end it's still 200w in your cabinet. More efficient is of course better because your plants can use more light. But with 6s3p you only need ~120v and get only 170w net. So more efficient and still enough light for 4ft² ..
 
How hot do people expect their drivers to get? I'm running a 240H-36A with 8 cobs, my kill-a-watt is reading 199 watts (I turned it down) and the driver is very hot, too hot to comfortably keep my hand on for more than a second or two.

Adding numbers here:

It's a 240H-36A with 8 CXB 3070s run in parallel

Killawatt reads: 119.9V, 1.67A, 200W
 
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Mary's Confidant said:
How hot do people expect their drivers to get? I'm running a 240H-36A with 8 cobs, my kill-a-watt is reading 199 watts (I turned it down) and the driver is very hot, too hot to comfortably keep my hand on for more than a second or two.

Adding numbers here:

It's a 240H-36A with 8 CXB 3070s run in parallel

Killawatt reads: 119.9V, 1.67A, 200W
Click to expand...

That's normal behavior at 120vac. If you look at the datasheet you'll see there is a 2-3% effiency difference between 120, 230 or 277vac. If you want them to run cooler you need to get a 120 to 240v transformer(sorry, language barrier).
For now you could mount the driver vertically on a wall to increase convection. Not much but maybe 2-3° less..

Screenshot_20180730-183902.png
 
Randomblame said:
That's normal behavior at 120vac. If you look at the datasheet you'll see there is a 2-3% effiency difference between 120, 230 or 277vac. If you want them to run cooler you need to get a 120 to 240v transformer(sorry, language barrier).
For now you could mount the driver vertically on a wall to increase convection. Not much but maybe 2-3° less..

View attachment 4173468
Click to expand...

Directing a small fan to blow across it drastically reduces the heat, I could pick it up or put it against my inner thigh without issue. Just wanted to make sure it wasn't a sign of improper wiring, bad driver, etc.

Thanks for the reply.
 
Mary's Confidant said:
How hot do people expect their drivers to get? I'm running a 240H-36A with 8 cobs, my kill-a-watt is reading 199 watts (I turned it down) and the driver is very hot, too hot to comfortably keep my hand on for more than a second or two.

Adding numbers here:

It's a 240H-36A with 8 CXB 3070s run in parallel

Killawatt reads: 119.9V, 1.67A, 200W
Click to expand...
What is your ambient temp?
 
Hey
My addled mind can’t work it through
How do you ajust a dimmer on a driver??
The part about small screw driver in pot and turn I understand.
But how do you measure the adjustments you are makeing??
What tools needed to measure current??

Thanks!!!
Enjoying the haze
 
Mary's Confidant said:
How hot do people expect their drivers to get? I'm running a 240H-36A with 8 cobs, my kill-a-watt is reading 199 watts (I turned it down) and the driver is very hot, too hot to comfortably keep my hand on for more than a second or two.

Adding numbers here:

It's a 240H-36A with 8 CXB 3070s run in parallel

Killawatt reads: 119.9V, 1.67A, 200W
Click to expand...

Randomblame said:
That's normal behavior at 120vac. If you look at the datasheet you'll see there is a 2-3% effiency difference between 120, 230 or 277vac. If you want them to run cooler you need to get a 120 to 240v transformer(sorry, language barrier).
For now you could mount the driver vertically on a wall to increase convection. Not much but maybe 2-3° less..

View attachment 4173468
Click to expand...

Random, I turned it down to .5 A and 57 W and there is almost no perceptible heat. I'll turn it back up as they get older
 
Tejashidrow said:
Thanks!!!!
I woke up clearheaded this morning and realized the same thing.
So before I got up to pee, I ordered a
“Killawatt” off amazon ( Allways think of Wonder Woman when I Order there...)
Be here tomorrow
Technologies such a wunerful thang....
Peace
Click to expand...
You really need a multi-meter hooked up at the output of the driver to the first set of strips or cobs to get an accurate reading as to what the driver is putting out as far as amps or volts. Using a kilowatt meter is only going to give you an idea of overall power consumption which will include some losses from the efficiency rating of the driver.
 
Mary's Confidant said:
Random, I turned it down to .5 A and 57 W and there is almost no perceptible heat. I'll turn it back up as they get older
Click to expand...

Yea, no wonder it only takes 57w and also when less efficient(let's say 86% eff. at 20%) it's a lot less heat spreader over the driver surface.
Is it mounted vertically? Vertical orientation optimize passive convection because warm air like to flow upwards. It's not much but 2-3° less than horizontal at least.
 
Randomblame said:
Yea, no wonder it only takes 57w and also when less efficient(let's say 86% eff. at 20%) it's a lot less heat spreader over the driver surface.
Is it mounted vertically? Vertical orientation optimize passive convection because warm air like to flow upwards. It's not much but 2-3° less than horizontal at least.
Click to expand...

It's mounted outside of the cab in a horizontal position but I've just clipped a fan on the outside to blow over it and it doesn't feel appreciably warmer than ambient temps. When I was running it at 200W, it got very hot but again, the fan blowing across the top of the driver really helps keep it cool.
 
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