LEDgardener

Hello everyone!
Im totaly new on this whole led thing.
But i have become interested and now i want to build my own grow light.

I was thinking of running two of these chips:
https://www.digikey.com/product-detail/ ... ND/6557080

With this driver:
https://www.digikey.se/product-detail/e ... ND/7704014

That would be two bridgelux vero 29 cob chips with forward voltage 50.7v
3000k 90cri 3.6A max current.

So this driver can handle 71-143v and provides 1750mA.

So each chip will deliver 88.725w

Ive allready ordered the driver lister above and one cob plus one heat sink. But in order to use this driver i have to use two of these chips. But is it possible to mix chips in the same circuit and also buy for example this chip:
https://www.digikey.com/product-detail/ ... ND/6557094

A similar chip to the one i bought but a 36.6v forward voltage and higher max current.

So my questions are, is it allright to do like this?
Use two 50.7v and one 36.6v chip and connect them all in series and power with the driver i listed?

Or should i go with just two chips that are the same?

Also wondering what you guys would have done when it comes to color temperature? This chip i have allready is a 3000k. I was thinking about just getting two of those. But I could also go with another one maybe?

If it is possible to mix different chips like i asked above, maybe it would be a good idea to use 5000k on the third, the 36.6v chip, in order to get some more of the blue light and therefore be a little more allround as it would perform better in veg also?

Im also a little concerned about the heat sink. I ordered this one:
https://www.digikey.com/product-detail/ ... ND/4215388

But today when i got it, it seemed small. Anyone know anything about the heat sink i linked? Actually i have thoughts about making my own heat sink in the future. Just cnc mill out of aluminium. But for now I just wanted to try build a simple grow light.


So any input on this?

Hey. No problem throwing that 36v COB onto the series circuit with the 2 50v COBs with that driver. The only thing is the 36v COB will be only maxing out near 65 watts so will be running lower power than the others.

If it's for a flower light then the 3000K lights sound spot on. You could get another of the 50v Veros in the same 3000K and then use the lower power COB as a tweak for your plant morphology. A 2700K vero would add even more reds and help your flowers finish slightly faster, and give them a bit of leeway to stretch up slighty more. If you want to keep the plants short you could go with a 3500K or 4000K to add in more blue and help keep the node spaces tight as they grow up. The higher color temp models would allow you to create more flux with the lower wattage so you could get more photons out of the 4000K for example than the 2700K. Mixing a 5000K in with the flower lights sounds a bit out of sorts to me, just a little too much blue. But you could try it and again you would get the most flux out of your wattage.

Those heatsinks do look small. Don't see any specs. Did you just grab one because it says Vero? Likely not enough metal and surface area for the amount of power you want to run to your Veros in this application. You could maybe use PC fans to try to cool the shit out of them. You would really want to be looking for a nice 140mm or larger pin heatsink for pushing the 90 watts per cob passively cooled. Check out some of these options and make sure to look at the power handling capabilities before jumping on anything.

Here are some alibaba options for lowest costs.
https://kingbriteled.en.alibaba.com/pro ... tsink.html[/url]

Here is what I use for my COB's from RapidLED. They have an entire 'substrate' rail building system they work great with.
https://www.rapidled.com/140mm-pin-heatsink/

Let me know if any other questions.

I think I found the heatsink data. Looks to be inadequate, unfortunately.

https://datasheet.octopart.com/NX301103 ... 997282.pdf

Thank you very much for the input!
Yeah, just grabbed a heat sink a little to fast, it said "vero 29" somewhere

Anyway, maybe build myself or iil have to buy bigger.

This build is mainly just for building it.
So i dont have any specified use for it. Therefore im thinking about doing it more allround. Thats why i thought about the 5000k chip also to add more blue.
I like them short and like small bushes rather than stretchy ones. But as you say, 3500 or 4000k might be enough.

Another thing, i think this chip I got here is a solderless one. Am i supposed to just stick a cable in one of the holes?

I think it was on this forum i read in some thread about other europans that takes about they had to go with active cooling cuz it would be to expensive to order big enough heat sink. Iil check into that alternative also, maybe that would be cheapest for me

DaveJonesFan wrote: ↑

Mon Jul 23, 2018 1:15 pm

Hey. No problem throwing that 36v COB onto the series circuit with the 2 50v COBs with that driver. The only thing is the 36v COB will be only maxing out near 65 watts so will be running lower power than the others.

If it's for a flower light then the 3000K lights sound spot on. You could get another of the 50v Veros in the same 3000K and then use the lower power COB as a tweak for your plant morphology. A 2700K vero would add even more reds and help your flowers finish slightly faster, and give them a bit of leeway to stretch up slighty more. If you want to keep the plants short you could go with a 3500K or 4000K to add in more blue and help keep the node spaces tight as they grow up. The higher color temp models would allow you to create more flux with the lower wattage so you could get more photons out of the 4000K for example than the 2700K. Mixing a 5000K in with the flower lights sounds a bit out of sorts to me, just a little too much blue. But you could try it and again you would get the most flux out of your wattage.

Those heatsinks do look small. Don't see any specs. Did you just grab one because it says Vero? Likely not enough metal and surface area for the amount of power you want to run to your Veros in this application. You could maybe use PC fans to try to cool the shit out of them. You would really want to be looking for a nice 140mm or larger pin heatsink for pushing the 90 watts per cob passively cooled. Check out some of these options and make sure to look at the power handling capabilities before jumping on anything.

Here are some alibaba options for lowest costs.
https://kingbriteled.en.alibaba.com/pro ... tsink.html[/url]

Here is what I use for my COB's from RapidLED. They have an entire 'substrate' rail building system they work great with.
https://www.rapidled.com/140mm-pin-heatsink/

Let me know if any other questions.

Great answer. I agree about the 5000K for a flower light - you're probably better off subbing in a lower color temp. A lot of pin fin heat sinks now come with max power recommendations from the vendor, which is a huge help. Like DJF said, running them hard at ~90 watts will require a big passive sink. You can always add a fan to help as well.

Tassetapir wrote: ↑

Mon Jul 23, 2018 3:32 pm

Another thing, i think this chip I got here is a solderless one. Am i supposed to just stick a cable in one of the holes?

Yeah, you just strip it back and push it in and a little metal tab will trap it in there. They're so much nicer than soldering.

Thank you very much for the time you are spending on helping me! Greatly appreciated! Even though my language might be wierd, english is not what we speak here

About the color temperature, then iil go with the 3500k if i decide to add more light.

As i work as a cnc technician i make things all day out of different metalls. It wouldnt be that much big of a problem build something myself. I am looking around after someone who have taken a piece of metall and milled their own sink.

Ive done some reding here about how to calculate the right heatsink but is seems easier to look at something i know work and then build something similar. Just over do the cooling a little so i know im safe. But yes some kind of fan seems good. Maybe make connections for small ventilationtube so the sink can work as a cooltube for a hps. Exept the air is blowing, from outside the tent via the tube, right by the sink, and then blown out of the tent again.

Anyone seem someone mill their own sink for leds?

Operations like this following youtube links wouldnt be problem for me:

Hey. Didn't even notice on the English. You're doing well there, enough to have a nice technical discussion. Thanks for that.

The 3500K is the temp of COB I run, in the 70v type Vero 29 in my application. Good choice there. It's the spectrum most of the made-for-market light fixtures have used historically with COBs. It was shocking in it's ability to suppress stretch compared with the 600w HPS light spectrum it replaced. I only notice overcrowding causing stretch now since implementing them as the primary light source. So much so that I added 3000K lights into the same space in the form of quantum boards, and now run the same color temperature mix you are considering. Great mix for veg and flower alike.

Awesome stuff on the CNC milling. You could make something pretty sweet in that case. I might be jealous and asking you to send me over some hunks of non-ferrous goodness. I haven't seen much in this space personally done in this manner. A lot of the options I see integrated I believe are forged or extruded (but maybe more of it is CNC made than I know) and easily enough available here in the USA. Anodizing seems popular on the highest performing aluminum applications, but that is not something I have much intimate knowledge of. Just make sure you have lots of weight and design to get surface area exposed.

I do personally love active cooling. I run the 140mm pin heatsinks referenced previously that are best for 70-80 watts passive cooled, but can be run up a bit higher with good grow room circulation, at up to 95 or more watts with some very inexpensive 120mm fans. They are low power PC case fans run at .16A each, sold in a pack of 4 and easily found on sale for under $10 US. Not fancy but they are plenty fine for getting what I need from them.
https://www.newegg.com/Product/Product. ... 6835103052

I run all 4 of them in a parallel config easily on a Meanwell APV-8-12 driver and that can cool a bar packed with 4 high power Veros (Or 3 veros and the driver ) very well. This sort of set up is well worth the cost, effort and potential maintenance to me. Many just don't realize how easily active cooling can be implemented thoughtfully.
https://www.jameco.com/z/APV-8-12-MEAN- ... 26290.html

A pic of my setup from when I was putting them together. I think this was before I realized I mounted them upside down, but it's the sharpest focus of the pics I took at the time.
Here is my chance to share this amazing video that I believe deserves more views.


Stick with the SE models of the Veros to retain the no-solder design.


Cheers!