COB (chip on board) led 50w warm white


I have here a cob led 50w that I need a driver for, and what else should I get to build a simple 50w single cob led for vegging. Another question that should probably be in a separate thread, can I use 3500k warm light in veg?

Tags @dbrn32 @latewood @garrigan65 @Matthew1280 @Covertgrower @Countryboyjvd1971


Heat sinks! A large enough for use with out a fan. I have to pick one of COB’s up myself to replace the burned china ones I have that went bad. @AmnesiaHaze


Same here I bought a China led COB it had one bad LED driver, and I have this extra (chip on board) COB left over.

I was also thinking of buying another led light and swap out the full spectrum COB with this warm;white COB. To use for seedlings and vegging purposes only. I found this COB on amazon: COB 200W LED Grow Light,Full Spectrum LED Plant Grow Light for Indoor Plants Veg and Flower (COB-200W)

I can disassembled the light and swap in the COB I have. (I want to use it becuase it’s warm white light and not the pick full spectrum I usually see, is like to have a light in the tent that I can see deficiencies and or other problems


Do you have a data sheet for the cob?


Short list is…

Heat transfer compound
Mounting hardware
Plug and/or cords
Hookup wire
Handful of sturdy electrical connectors, or solder and heat shrink


Yes. Actually here is the description of the parts I bought.

Specifications(LED Chip):Product Name: LED SMD Chip
Input Voltage:DC 31-36V
Forward Current(IF):1500-1750mA
Light Color:Warm White
Wave Length (Color Temp):3000K-3500K
Life span:50,000 hours
Size:51.5 x 46mm/2 x 1.8 Inch(L*W)
Application:For Led Floodlight /Spotlight DIY

Specifications(LED Driver):
Model type: 50W LED Driver
Input voltage :AC85V-265V 50-60Hz 0.8A
Output voltage: DC 24-36V 1500mA(+/-5%)
Waterpoof Rating: IP67
Total Weight: 262g

Widely used in Traffic lighting, Landscape lighting, advertising lighting, Indoor Lighting, Special lighting.
Landscape scene / spot lighting,Architectural lighting,Display scene,Artwork lighting,general lighting.
Amusement park scene,Aquarium lighting and so.

Package content:
1 x Led LED SMD Chip
1 x Waterproof LED Drive

I was wrong it is a 50w COB which means my China 1200w led is falsely advertised!!! It’s really a true 300w with (6) 50w COB led full spectrum. That’s why the true wattage is 250-270 Watts it’s 300w but loses that 50w-30w from draw and current changes in the circuit to power fans, drivers, etc to keep constant wattage and your lights won’t dim while running.


Thanks buddy I will be writing down your list you made for me to use for future projects!


You can substitute things on that list. But that’s essentially what it takes. No problem!


Outa likes! But thank you @dbrn32


I would suggest going with a constant current constant voltage driver, or constant current. You can essentially run it at any current you want then. The higher the current will be more output but less efficient and you’ll need larger heatsink. If you’re happy with 50 Watts, I can find some drivers that will work. Do you want to have dimming function? It’s nice, but more expensive and will require a few extra components. You could always get dimming driver now, and buy pot and resistor later too.

3500k isn’t bad for begging, just not as good as colder temps like 4000k-6500k. You’ll see a couple extra inches in plant height is all. The big difference is the colder temps have higher efficacy, meaning more light per watt. No biggie though, it will work.


Out of likes, but @dbrn32 is clearly the more experienced person that came up with a more detailed list than I did. Thanks for being awesome @dbrn32


There’s no such thing as too much information. Every contribution helps @Covertgrower


This one is constant current and it works perfect in my China LED (1200w) supposedly.

uxcell 50W LED Driver Waterproof IP67 Power Supply High Power Adapter + 50W LED Chip Bulb Energy Saving For DIY Warm White

But I recently found that on my China 1200w COB LED that all (6) COB’s and LED drivers are 50w that makes it a true 300w light. So I have a pretty powerful COB LED. I’m happy with my flowering lights. Now that I fixed them, I now need a white light for vegging. 3500k is warm light and is supposed to be used for 12/12 lighting.

But as I assume, any type of light on the spectrum, (besides green); for more than 12 hours will promote photosynthesis lmao.


The majority of people growing with 3500k cobs use them from seed to harvest. If you were to go out and buy one, I would suggest 4000k or 5000k. But if you already have the 3500k it will work.

Do you already have that driver? If not, it probably wouldn’t be that much more expensive to get something with dimming function that runs more efficiently. Up to you really


I don’t have the driver currently. I only have the COB left over from spare parts I used to fix the other light I have. I need to buy a driver and a heat sink, and a lens for that matter and some wiring adapter ends(male/female) plus a plug to power the driver, and I have solder and my solder pen.

So parts I need:
Driver 50w
Plug for driver to power it
Heat sink w/ fan for 50w COB

I have extra yo-yos but I would need those metal strings with the loops on each end that you clip on to your light so the yo-yos can work without issues


You can drill a hole in heatsink to mount them if need be. I usually install an eyebolt or hook. But those cables can be made at like an ace hardware if you have access to one.

You can get a pin heatsink from hlg, cobkits, rapid led, or I’m sure a number of other places for around $20. Doubt the standard mounting holes will work though, so you’ll probably have to drill and tap. Or a cpu cooler will work, but then you’ll need power supply for fan as well.

Did you say you already had thermal transfer compound?


Out of likes, thanks for that @dbrn32 and no I do not have thermal paste, I have amazon prime I will most likely source a lot of my led parts from there as I have before in the past.


I’ll buy wire, wagos, and stuff like that on amazon. But they don’t typically have the leds, drivers, and heatsinks I’m looking for. If they do, price is rarely competitive.

Arrow electronics usually better than prime too. Free next day air on orders over $20. Good source for drivers and leds, but their website is difficult to navigate on mobile browser


Awesome I’ll check out Arrow @dbrn32 thanks for that :+1:


@dbrn32 has you covered here i would just follow his direction
@AmnesiaHaze he’s good with the lights bro
Woohoo happy growing boys