DIY COB grow light

[bombbudpuffa]

What you'll need-

COB led chips. Cree CXB3590 and Vero29 are the most popular. I haven't used either so I'll just use for an example what I use. I use the citizen clu048 1212 chips. They're rated at 36v, 2800ma max.

Led driver. My chips are rated 36v, 2800ma max but typical or preferred ma is 1400. Your chip runs cooler, color is more true and you get a better lumen per watt. Volts and amps are the 2 most important things when it comes to choosing chips and drivers. More later.

Heatsink There are 2 kinds. There's active heatsinks and passive heatsinks. Active heatsinks implement a fan for cooling. Passive heatsinks just cool from a large surface area. If you're an efficiency freak use passive. If you don't mind the extra electricity and want your heatsinks to literally feel cool go with active.

Power source I just use a 110v ac plug

A word on voltage and ma. If I want to run my 36v chip I need at least a 36v driver. It can be 40v, 70v, or 100v just as long as it's more than what the chip is rated the chip will come on...look at volts like your cars ignition and the COBs like your car. If you want to crank your 36v car you'll need a 36v+ ignition. Look at your amps (or ma/milli amps as they're listed on most drivers) as your cars gas pedal. The harder you push that pedal the faster, or brighter in an leds' case, the car will go. Most COB run most efficient from 50-75% their max ma rating. So my 36v, 2800ma max chip should be run at 36v, 1400ma for the most efficiency.

Pictured in order-

COB chips
Drivers
Heatsinks

Instructions on putting together, different designs and links to parts up next. I might need to edit something as I'm exhausted lol.

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[bombbudpuffa]

So, here's my latest light. Using 3 36v chips. In order to find the right driver to run three I had to multiply 36 x 3 which gives me 108v. So, I needed a driver with, at least, a 108v output. I went with this inventronics driver with an output of 142v at 1050ma.

Since I'm using active heatsinks, or heatsinks with fans, I either had to find a 12v power supply or use a driver on them to wire them in line. Couldn't dig up a driver that could run all three so they each got a driver. The drivers are $1 each so no biggie.

Easy to hook up. I'll get into the details next post.

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[The Hemp Goddess]

I admire the @#$% out of you that can build your own LEDs. I think this is just so impressive!

 

[bombbudpuffa]

I admire the @#$% out of you that can build your own LEDs. I think this is just so impressive!

Thank you THG but, I promise, anyone could do it. You can make one without touching a soldering gun. I'll show you how easy it is.

 

[Rosebud]

Me too, what THG said. Color me impressed. You rock BBP!

 

[bombbudpuffa]

Me too, what THG said. Color me impressed. You rock BBP!

Thank you rose!

 

[bombbudpuffa]

So, I'm going to put one together and let you all follow along.

I'll be using 5 Cree CXA1304 9v chips

https://www.ebay.com/itm/Cree-XLamp-CXA1304-led-3-7-10-9W-COB-Natural-White-5000K-9V-LED-Chip/321634797906?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

They'll be held by these solder less COB holders

http://www.newark.com/ideal/50-2000cr/led-holder-cree-cxa13-cob-array/dp/39Y2341

I'll be using a 680ma dimmable driver...cheap version from china. 5x9v=45v at least.

https://www.ebay.com/itm/7-12pcs-x-3W-36W-for-Dimmable-Constant-Current-Power-Supply-LED-Driver/261650585356?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I'll be using these lil heatsinks with a 12v 100ma fan attached to it.

https://www.ebay.com/itm/5pcs-10W-High-Power-LED-Silver-Aluminum-Heatsink-with-fan-light-Cooling-Cooler/141909040697?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I'll need a couple 300ma drivers to run the fans

https://www.ebay.com/itm/AC-DC-Transformator-LED-Driver-Netzteil-Trafo-1-3W-4-7W-8-12W-12-18W-300mA/291657462343?ssPageName=STRK%3AMEBIDX%3AIT&var=590691556774&_trksid=p2057872.m2749.l2649

Back in the morning with prep...including drilling and tapping the heatsinks, cleaning everything and heatsink paste and options.

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[umbra]

awesome

 

[bombbudpuffa]

A quick word on the chips and holders. Each chip has a + and - side. The holders are made so the + matches with the +, - with -. If you look closely in these pics you can see the +- on the chip and how I have the chip positioned in the holder with + to + and - to -.

This is also how your chips will be wired together...+ to - to + to - and so on. I'll show you in detail later on in the build.

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[bombbudpuffa]

Mounting your chips

I'm going to use some 3m double sided tape and a couple 1/4 inch 4 40 screws. First I have to remove the fans to drill the holes for the chips to be mounted. I'm removing the fans so they aren't damaged by my drill.

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[bombbudpuffa]

Next position your chips on the heat sink, making sure to avoid the fans mounting holes, and mark the spots you want to drill.

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[bombbudpuffa]

Now, the aluminum is slippery so you'll need to put impressions in the metal for your drill bit to go in to avoid it sliding offline. I used a hammer and a nail. Then drilled the holes.

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[bombbudpuffa]

Adding threads is a @#%#@$%!! You need to be very careful because the bits break very easily. What you have to do is oil your bit, start drilling very slow and at the least sign of resistance, stop and back the bit out. Clean the metal from the tap and repeat until your threads are in.

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[bombbudpuffa]

Take your double sided tape and place it on your heatsink, stick your chip to it, making sure your holes line up. Take your time because the tape is crazy sticky. Put your screws in and put your fan back on.

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[bombbudpuffa]

Now you have a chip mounted to an active heatsink. To be continued...

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[2RedEyes]

Hey Puffa, thanks for posting this stuff. You got me checking out YouTube for diy grow lights. I can see something like that in my future. Gotta lot of research in to do though...

 

[bombbudpuffa]

No problem at all.

Next you want to get an aluminum angle. This will be used for framing your light. Now I was just going to drill holes and use the plastic push through on the fan and push them through the holes. I decided against it, removed the plastic push through and tapped and screwed the heatsinks in place. Remember, mark your drill spot then indent it with something so your drill doesn't slide.

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[bombbudpuffa]

As you can see in my last pic the fans leads were too short so I soldered extra to it, pull tied all the wires together and secured them to the frame with pull ties.

Don't mind my weird wiring. Couldn't find my black wire so green is - and red is +.

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[St_Nick]

Iffn you don't mind, whats the purpose of the double sided tape. Surely you didn't put it between the heat sink and the chip? The only thing that should be between the chip and the heatsink is heat sink compound which improves thermal transfer although I assume the tape is at least thin. Chances are the glue will wind up cooking hard like varnish

 

[bombbudpuffa]

The double sided tape is used as a heat sink adhesive for low watt led. I've used them several times for this exact purpose.