Help needed please: small LED seedling & veg light for 50cm x 50cm x 100cm

[Greensalt]

Hi Everyone,

I am in the UK and as the title suggests, I'm after some help please as my original idea of using a HLG QB144 has been dashed. Bought a suitable driver ultra cheap at £5 with vouchers and nectar points (MeanwellLPF-40-39), plan to modify an old PC heat sink and then found out that the last QB144 had been sold and currently no stock in the UK.

Now I am left with the Meanwell LPF-40-39 and the PC heatsink which is 2/3rds of a small reasonable seedling/veg light putting out a max wattage of approx 40watts BUT no actual light source.

I was thinking, could I use a COB LED such as Citizen/Cree instead?

I do not need massive output and the driver only has a max of 40watts, see below the drover specs:

Operation Mode:	Constant Current (CC)
Output Current-Channel 1:	1.12 A
Output Voltage-Channel 1:	36 VDC
Output Power:	40.32 W
Input Voltage:	90 VAC to 305 VAC, 127 VDC to 431 VDC

As for the PC heatsink I could modify, I have taken a picture of it below and as you can see, it is a fin type. There is a flat smooth spot that measures 1.75" x 1.5" which I am assuming would be enough area to fit a suitable COB LED with thermal paste/pad.

I am not even sure if a heatsink would be needed for a COB at a max of 40watts?

So there we have it, a 36V, 1,12A driver putting out a max of 40watts and a heatsink with a nice spot to house a COB LED but which one, which brand......I seriously have no clue were to start.

Can anyone help please?

 

[donkeyjunk]

Sorry mate...not a clue.
But if you go to grasscity forums, there’s a guy in NZ that has just done roughly the same thing.
Hit Doobie Noobie up

 

[Greensalt]

Sorry mate...not a clue.
But if you go to grasscity forums, there’s a guy in NZ that has just done roughly the same thing.
Hit Doobie Noobie up

Thanks, I'll have a look

 

[Greensalt]

Sorry mate...not a clue.
But if you go to grasscity forums, there’s a guy in NZ that has just done roughly the same thing.
Hit Doobie Noobie up

I've had a look and he is building with 4 COBs so totally different using more power

 

[Greensalt]

Can anyone else help please?

 

[Greensalt]

Not a single person can help, I'm shocked

 

[Paul Squiggle]

Not a single person can help, I'm shocked

Hi mate, I've just seen your post. Sometimes things do get over looked and they need bumped once and a while. Give me 5 mins to digest the info and I will get back to you

 

[Paul Squiggle]

I'm back. I knew I had seen a company that sells horticulture light supplies.
They are called vivid Led they've got Qb144 and thousands of others to choose from.. there's a lad on here called @VetSmoke85 from the UK also. he built his own light. Search his threads and see if it helps

 

[VetSmoke85]

Give me a little time and I'll find a suitable COB for you. Probably a CLU 48. You could build a small strip light using Bridgelux strips but you'd need a different driver. Here's the link to my build.

Cheap DIY LED strip build

I made a DIY flower tent from an old canvas shoe rack and needed a light. The dimensions are 60x30x90cm. Not many quality lights out there to fit the space so I decided to build my own. After searching online and reading guides I opted for a strip build. Part of this plan was to keep costs as...

www.420magazine.com

I have a 4000K 65W HLG board that I started out with in a small cabinet. Then you couldn't get hold of them here in the UK anymore.

 

[VetSmoke85]

One of these would work with that driver.

CLU048-1212C4-50AL7K3

 

[VetSmoke85]

Or these boards are in stock.

ISH150R pcb​

 

[Greensalt]

Wowzers, I ned so time to digest but most of all a very sincere thank you, both @VetSmoke85 and @Squiggle for all your valued info.

Checked VIVIDLED and no 4k left of the QB144, only a few 3k Alexander (owner) informed me which is not ideal for me especially now a COB seems to be a better option given the heatsink I have has a nice placement spot as seen on the pics.

Would a heatsink be needed with the suggestions and what would be the output regarding wattage?

Sorry for all the Qs but I'd rather follow the experts than wing it when I am far from sure.

 

[VetSmoke85]

A heatsink is always a good idea. You'd be just under 40W with that driver.

That chip you'd be driving a little over the test current so it won't get too hot but having that heatsink will make sure it doesn't and will preserve it's lifespan.

 

[Greensalt]

One of these would work with that driver.

CLU048-1212C4-50AL7K3

That is the 5000k right!

Good for seedlings/early veg

 

[VetSmoke85]

That is the 5000k right!

Good for seedlings/early veg

Exactly mate.

 

[VetSmoke85]

If you did want the option to flower with it or grow a little auto under it I'd get the 3500K chip.

 

[Greensalt]

One of these would work with that driver.

CLU048-1212C4-50AL7K3

If you did want the option to flower with it or grow a little auto under it I'd get the 3500K chip.

Hi again @VetSmoke85

I think this is, or very similar to, the 3500k chip you mention but also includes the holder and thermal pad for a decent price.

eBay item number: 293377974144

You originally suggested the 5000k chip but in my experience, albeit HPS, I have used as high as 5700k for seedlings/early veg and I have never seen any noticeable difference compared to between 3k and 4k so might just grab this.

I might go with this....wadda think?

 

[VetSmoke85]

Hi again @VetSmoke85

I think this is, or very similar to, the 3500k chip you mention but also includes the holder and thermal pad for a decent price.

eBay item number: 293377974144

You originally suggested the 5000k chip but in my experience, albeit HPS, I have used as high as 5700k for seedlings/early veg and I have never seen any noticeable difference compared to between 3k and 4k so might just grab this.

I might go with this....wadda think?

That's the one I'd get too. Suggested the 5000K as you said it would be for seedlings/veg but 3500K will do that just fine and will work for flower if you want too.

 

[Greensalt]

@VetSmoke85 i love you, if you know what I mean hehe

I'll get it sorted and show you what I've created hopefully.

One doubt I do have...making threaded holes in my heatsink and what size. I'm guessing I need to do this to secure the holder right?

 

[Paul Squiggle]

@VetSmoke85 i love you, if you know what I mean hehe

I'll get it sorted and show you what I've created hopefully.

One doubt I do have...making threaded holes in my heatsink and what size. I'm guessing I need to do this to secure the holder right?

I can help out on this one.. Im a metal fabricator of 30 years. drilling and tapping holes is a daily thing. So when you get your bits and pieces, I will guide you through the process..
Do you have a drill or can you borrow one for half an hour?