DIY LED utilizing existing drivers

OldSmokie76 · Jan 20, 2020

Any help or push in the right direction is much appreciated. Any led builders out there? My goal is to use some existing drivers from a couple blurples to power some new tech. Either cobs or strips. Ultimately, this diy led will be inside a cabinet grow. If i can only get a small veg light together, so be it. Here's what I'm working with.

The donors: 1200w off brand led.
300w off brand led.

Drivers are pictured:
4 ea in 1200w plus a power supply
2 ea in the 300w

Any assistance in this project would be greatly accepted.

BigCube · Jan 20, 2020

If you dont have a VOM, you shouldn't even think of building your own fixture from spare parts.

What are you trying to do exactly?
Reuse just the drivers for leds other than the kind the fixture came with? Might not be possible.

LED drivers are either constant voltage or constant current. The leds must be chosen and oriented accordingly.

Step one would be figuring out the drivers, if you have a VOM its trivial. If you dont, you shouldn't even bother.

OldSmokie76 · Jan 20, 2020

I understand using meter to accurately giraffe the drivers, but i was hoping a simple decoding of the numbers on label couple help me decide what i could run with them. I was only going to build out what these drivers could handle. Basically a first time project for some experience before I go all in on something more expensive. Is it worth the hassle to use these or not? I tried looking up the one from the manufacturer with no specific luck. Just decided to reach out to the farm for any suggestions. Putting a meter to them would be priority right now i guess if the general info can not be had from the labels.

BigCube · Jan 20, 2020

OldSmokie76 said:
I understand using meter to accurately giraffe the drivers, but i was hoping a simple decoding of the numbers on label couple help me decide what i could run with them. I was only going to build out what these drivers could handle. Basically a first time project for some experience before I go all in on something more expensive. Is it worth the hassle to use these or not? I tried looking up the one from the manufacturer with no specific luck. Just decided to reach out to the farm for any suggestions. Putting a meter to them would be priority right now i guess if the general info can not be had from the labels.

If you have a VOM. measure the dc voltage output. You can basically add up LEDs until you get up to that voltage. Then banks of that till you cap out the wattage of the driver..

For example:

If your driver is 12v, you can use any leds that = up to 12v. So like 4 x 3v leds. Then run banks of those till you get within 20% of the drivers wattage.

But if you cant find leds that equal up to that voltage, you can under power your leds. Most leds accept a +- of at least .5v

So if your LEDs are 3.7v and your driver is 12v. You should run 4 at 3v each. Not 3 at 4v each, this would overpower your LEDs and they would burn out fast or right away.

Step 1 is finding your voltage, step 2 is choosing leds that you can run with your drivers. Step 3 is planning out the circuit, then build.

It's usually much easier to choose the leds you want, and the wattage you want it to consume, then buying your driver to fit your design.

If it was me, I wouldn't bother re using old drivers. Since drivers usually burn out faster than leds. Specially no name drivers.

Right now I'm building a fixture that runs on an old pc power supply. The 12v rail handles up to 195w at 12v. So I am using 49 x 3w 12v COB leds to make the wiring easy.

If you have any specific questions, I'd be happy to help

OldSmokie76 · Jan 20, 2020

BigCube said:
If you have a VOM. measure the dc voltage output. You can basically add up LEDs until you get up to that voltage. Then banks of that till you cap out the wattage of the driver..

For example:

If your driver is 12v, you can use any leds that = up to 12v. So like 4 x 3v leds. Then run banks of those till you get within 20% of the drivers wattage.

But if you cant find leds that equal up to that voltage, you can under power your leds. Most leds accept a +- of at least .5v

So if your LEDs are 3.7v and your driver is 12v. You should run 4 at 3v each. Not 3 at 4v each, this would overpower your LEDs and they would burn out fast or right away.

Step 1 is finding your voltage, step 2 is choosing leds that you can run with your drivers. Step 3 is planning out the circuit, then build.

It's usually much easier to choose the leds you want, and the wattage you want it to consume, then buying your driver to fit your design.

If it was me, I wouldn't bother re using old drivers. Since drivers usually burn out faster than leds. Specially no name drivers.

Right now I'm building a fixture that runs on an old pc power supply. The 12v rail handles up to 195w at 12v. So I am using 49 x 3w 12v COB leds to make the wiring easy.

If you have any specific questions, I'd be happy to help

Thanks for the insight. As much as I'd like to make these work, i also understand the benefit of using new drivers for build. Just for s&g, the one driver is showing output of 46-75v. Does that suggest i could run a total of LEDs up to 75v? Unfortunately, that driver does not list wattage. The other driver shows a max wattage of 150w-200w, but no volts. Still best to meter them... About to scratch this project.

Bema · Jan 20, 2020

Hey Smokie
Is it worth considering mains LEDS without the drivers, cooling may be an issue in the existing frame though.
Aliexpress has loads of LED chips and I've built using some of them.
They have also have white - warm and cool lights if you don't want "grow" lights. My 50w cob "full spectrum" LEDs cost around £10 ($12-15) to build.

Link to my "el cheapo post" and I'd heed some of the warnings I was given by others.
Good luck

BigCube · Jan 20, 2020

OldSmokie76 said:
Thanks for the insight. As much as I'd like to make these work, i also understand the benefit of using new drivers for build. Just for s&g, the one driver is showing output of 46-75v. Does that suggest i could run a total of LEDs up to 75v? Unfortunately, that driver does not list wattage. The other driver shows a max wattage of 150w-200w, but no volts. Still best to meter them... About to scratch this project.

46v to 75v fluctuation sounds like a constant current driver to me. It should have a ma or amp rating. Like 0.7a or 700ma. If this is the case, it will power any leds that requires 700ma. Up to about 10% of the drivers voltage.
So if the driver gives 700ma or 0.7amp you can use any led that requires 700ma or 0.7a up to around 90% of the max voltage.

Are you wanting to build your own fixture just for fun? Cause it can be done cheap and easy, or expensive and hard lol.

As I've said, I'm working on a fixture for a small grow box one working on. It's being built on a scrap piece of aluminum road sign.

The driver is a computer power supply that will give me 12v (195w) 5v and 3.3v. (Shares 200w)

The white light is going to be 7x7 3w warm white COB LEDs at 12v. Totalling 147w. Plus 30 1w deep red leds running off the 5v rail. All together 174w of LEDs, but the actual draw should be more like 150w. Since 1w leds arent 1 full watt and 3w leds arent 3 full watts.

Good luck on your endeavors!

OldSmokie76 · Jan 20, 2020

BigCube said:
46v to 75v fluctuation sounds like a constant current driver to me. It should have a ma or amp rating. Like 0.7a or 700ma. If this is the case, it will power any leds that requires 700ma. Up to about 10% of the drivers voltage.
So if the driver gives 700ma or 0.7amp you can use any led that requires 700ma or 0.7a up to around 90% of the max voltage.

Are you wanting to build your own fixture just for fun? Cause it can be done cheap and easy, or expensive and hard lol.

As I've said, I'm working on a fixture for a small grow box one working on. It's being built on a scrap piece of aluminum road sign.

The driver is a computer power supply that will give me 12v (195w) 5v and 3.3v. (Shares 200w)

The white light is going to be 7x7 3w warm white COB LEDs at 12v. Totalling 147w. Plus 30 1w deep red leds running off the 5v rail. All together 174w of LEDs, but the actual draw should be more like 150w. Since 1w leds arent 1 full watt and 3w leds arent 3 full watts.

Good luck on your endeavors!

It does state 700ma, but no max watt listed. Also constant current.

That sounds like quite the project. Full spectrum for what footprint?

Bema · Jan 20, 2020

OldSmokie76 said:
It does state 700ma, but no max watt listed. Also constant current.

That sounds like quite the project. Full spectrum for what footprint?

Hey Smokie
My grow room is 6' x 2.5' and I've used eight 50w cobs - There are 100 and 200w white (warm and cool) that may be better for you.
You could add heatsinks to the plate above the LEDs and let the existing fans blow onto the heatsinks - Both the leds and the heatsinks could be attached using CPU/heatsink glue.

OldSmokie76 · Jan 20, 2020

Bema said:
Hey Smokie
My grow room is 6' x 2.5' and I've used eight 50w cobs - There are 100 and 200w white (warm and cool) that may be better for you.
You could add heatsinks to the plate above the LEDs and let the existing fans blow onto the heatsinks - Both the leds and the heatsinks could be attached using CPU/heatsink glue.

All but two fans are shot. I'm only concerned with the drivers. I'll put together heatsink and led if i determine these will work. I believe passive cooling will be ok with the active exhaust of the cabinet I'll be utilizing. Actually, I'm planning a 2.5'x5', similar to yours. Divided up for clones, veg, and flower. Should be fun. Lol. I'm liking the combination of cobs and strips.

BigCube · Jan 21, 2020

OldSmokie76 said:
It does state 700ma, but no max watt listed. Also constant current.

That sounds like quite the project. Full spectrum for what footprint?

18x18x36 inch.

BigCube · Jan 21, 2020

The leds I'm going with are the 3w cobs:

The red:

If you've seen my micro grow box, you'll know what space it will light last run I used dollar store led bulbs totalling 105w of warm white. So this should be a step up, maybe even too much.

SkunkyDunk · Jan 21, 2020

I'm glad I just bought panels, for the price the labor of building one isn't practical.
One of the panels I bought would rock your cabinet! Under $200.00.
I bought 4 shipped was $726.00 for 960 real watts at the plug.

BigCube · Jan 21, 2020

SkunkyDunk said:
I'm glad I just bought panels, for the price the labor of building one isn't practical.
One of the panels I bought would rock your cabinet! Under $200.00.
I bought 4 shipped was $726.00 for 960 real watts at the plug.

A double 240w quantum board wouldn't fit in an 18x18 inch footprint a single 120w would, but that defeats the perpous of the project

I have several quantum boards as well, as I recall I suggested them to you at some point. The entire point of my build is to be %100 DIY, micro grow for cheap.

The last lights I ran were 7 100w eq (15w) led bulbs on a 7 bulb splitter. Worked good and got me 1.5g per watt.
12$ for the splitter and 28$ for the bulbs.

This would be an attempt to get even cheaper. Probably half the cost by the time its done.

My hobbies are growing and electronics. So I dont count my time, it's a hobby.
I could obviously buy a 100$ kingbrite quantum board and stuff it in there. But that would not be DIY. I already have 2 other bought tents full of bought fixtures and equipment. This is 100% fun. Not necessity.

BigCube · Jan 21, 2020

Here's the link if your interested. The new version is wood. Not panda. But dimensions are the same.

Home made micro tent.

So I made this tent a while back. Its 1.5x1.5x3. I've decided to see what i can get out of it. So I e started to scrog a clone. The frame is made from cheap 1x2 and panda film. Using 2 5v computer blower fans running on a USB outlet to exhaust. The light fixture is a 7 to 1 bulb splitter. That...

www.thcfarmer.com

DIY LED utilizing existing drivers

DIY LED utilizing existing drivers

OldSmokie76

Attachments

BigCube

OldSmokie76

BigCube

OldSmokie76

Bema

BigCube

OldSmokie76

Bema

OldSmokie76

BigCube

BigCube

SkunkyDunk

BigCube

BigCube

Home made micro tent.

Privacy & Transparency

Privacy & Transparency