DiY LEDs - How to Power Them

ANC

Well-Known Member
I thought you are using driverless COB?
If you didn't get a heatsink yet, get a large PC heatsink, a quality 3mm tap and a 2.5mm drill bit.
Mark and drill the right spots, and fasten screws half a turn, alternating after tapping. Remember to use thermal paste (as thin as you can get it on).

It only gains you single digit extra degrees C, but I like lapping my heatsinks and whatever I attach to it. even my PC CPUs get lapped. You take a mirror or glass from a frame or something really flat and hard. spray some contact glue on lightly. stick a sheet of 600 sanding paper on, and give it a light go to see where the low and high spots are. Work them away, and replace sanding paper with finer paper until you eventually get to 1000 to 1500 grit. You will be left with two mirror-like surfaces. Squeegee a seethrough thin layer of thermal paste with a safety blade on the heatsink and place your item to be cooled on with rotational motions to smooth it out.
You need to take them apart with the same motion, as the capillary action will suck that bitch on like glue.

Thermal paste is designed to fill microscopic imperfections between two surfaces. Slapping 2mm thick coats on reduces performance.

THE COLDER YOUR COB IS THE MORE LIGHT IT PUTS OUT.

I would run ground to the heatsink and any metal that could touch the live wires in the event of an earthquake even.
 
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ANC

Well-Known Member
THose look like shit hey.
999lumens for 50W
the 23W spiral CFLs I like using for seedling and young vegers are circa 1100lm
 

HydroRed

Well-Known Member
THose look like shit hey.
999lumens for 50W
the 23W spiral CFLs I like using for seedling and young vegers are circa 1100lm
Wow. Looked right over that

I actually mentioned this twice in my posts about them being 220V 50W 500-999 lumens (at least the ones @Delta-9Pyromaniac linked in their post) and got bucked the whole time. Those are garbage lights, they wont deliver 999 lumens as advertised, and your gonna spend twice what you saved trying to make them work how you are trying to make them work.
You coulda bought (4) standard led light bulbs from Home depot for $1 each that would deliver a comparable 750+ actual lumens with 9 watts each. Likely an additional 10% more lumens once you remove the diffuser.
Lets do some more math now....
4 bulbs @ 9W = 36W total.
750 lumens each x 4 bulbs = 3000 lumens.
Add the additional 10% lumens (300) after the diffuser is removed and you have a total of
3300 actual lumens at 36W for $4 and you dont have to do anything but screw in a lightbulb..
DSC_0128 - Copy.JPG
Good luck with your lights.:peace:
 

posativek

New Member
There are 18V and 9V (2 in series) such as:
Cree CXA1512 & CXB1310
Citizen CLU701
Bridgelux V8

The supplies will automatically adjust down to the forward voltage. The HLG can additionally be adjusted down to improve efficiency.

You could use a current balancing circuit to drive multiple CoBs in parallel with one supply. Without current balancing, the CoBs would run imbalanced and thermal runaway is a real possibility. I have attached a couple of app notes that explain the parallel issues.
N2Fg, I'm going to build a 175w light for a 1x1 space (head room no issue as such) and wanted to use 16 x cree 1512 3000k 93cri because they will run perfectly at 10w each, @18v will only require 1 x driver and will be 200w max for $200.

i cannot workout what the par would be of the light though (ppf etc). I want it to essentially replace 3 x3070's of 3 x 3590's @50w each which isn't optimum for either chip.

What say you?

plus I get excellent light coverage from 16 cobs over 3. Im just not sure about the Joule rating and if it is substantially less than say 4 x 2540's (same price for entire unit roughly) or 3 x 3070's I might switch to a more conventional 3-4 cob design for a square room.
 

1212ham

Well-Known Member
Yes, you just need to use the dimming function. I used an HLG-185H-48B on 44v Gen-1 strips.
I will use my HLG-240H-42B for my 19.5 volt Gen-2 strips. Strips will be wired series parallel.
 
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Delta-9Pyromaniac

Well-Known Member
I wouldn't.
Ground the fixture and use a ground fault interrupter. A fuse wouldn't hurt.
I appreciate the response but unfortunately with no experience I have no clue how to do that...? Not sure if I'm even going through with this set up. Thinking of getting luminus cxm22 gen3 90 cri with passive heatsinks. Problem is, because of my lack of experience I don't know what size driver to use.. Can you brake it down in layman's terms so someone with no experience like me can understand?
 

GBAUTO

Well-Known Member
I appreciate the response but unfortunately with no experience I have no clue how to do that...? Not sure if I'm even going through with this set up. Thinking of getting luminus cxm22 gen3 90 cri with passive heatsinks. Problem is, because of my lack of experience I don't know what size driver to use.. Can you brake it down in layman's terms so someone with no experience like me can understand?
Drivers are usually grouped by power output in watts. You need to decide if you want to drive your arrays with either a parallel or series circuit. Once you have decided on the chip you want to use and how hard you want to run each chip that will allow you to choose the driver current for series or forward voltage for parallel. Parallel circuits divide the current equally(hopefully...) between all of the chips in circuit(ie. 300w divided by 6 chips=50w/chip Say the chip has a forward voltage of 50v so it will use 1A of the available current from the driver(300W@50V= 6A total current available)). When running parallel driver you also need to make sure that if a cob fails that the remaining cobs can handle the additional power. I run my Vero's in series-makes certain that all of the arrays see the same drive current-downside is higher voltage, especially when running hi wattage drivers.
 

NoTillPhil

Well-Known Member
I would like help choosing a driver or drivers to use with these strips. Grow space is 4 x 2.5 and I'll be using an old four bulb t8 fixture as heatsink and frame.

Thanks for any help offered.

Won't allow me to share a link........ they are ACUITY LITHONIA 5000K LED light strips from AC light fixture sold in 8 packs on ebay for 23$. I would like to use 16 of them.
 
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