Wonder if big 1150x1150mm ALU plate would work for 5x - 8x 1212 driven at 700mA? Max. 100W of heat I think.Try ebay or am4zon but they are incredibly expensive at least the ones my quick search spits out!
On ebay you can find 5packs of CLU048-1212 gen.6 COB for ~50€. Get a five pack Intel coolers with build-in fans(the ones with copper core, socket 1155 or so) and a small 5v/1A driver to drive the fans and you are good to go. These coolers are also cheap, ~20€ incl. driver maybe. At last order a Meanwell HLG-240H-36A and wire the COB's in parallel(another 70€). So with a tiny bit effort you get away below 150€ for a 260/280w light!
https://www.amazon.de/GRO-DRONE-CXB3590-Light-Lampe-Germany/dp/B0784RGLKH
For sure, mate!Wonder if big 1150x1150mm ALU plate would work for 5x - 8x 1212 driven at 700mA? Max. 100W of heat I think.
Hmmm, with Citizen 1212 that seems great and cheap option.For sure, mate!
For proper passive cooling you need a surface area of ~55cm²/w or 110cm²/heat watt . Such a plate has 26.450cm²(115 x 115x 2) when we divide it by 55cm² it would be enough for ~480w LED power(assuming 50% efficient COB's) or ~240heat watt's!
I would add a few U-channels to the backside to make it stiffer. Plate should be at least 3mm thick, better 4mm to enable heat to better spread out. Added channels would increase the thickness too.
Have a look at my sig, the small 150w light has a selfmade heatsink I've made this way. U-channels are glued with doublesided thermal tape.
View attachment 4136222
Hmmm, with Citizen 1212 that seems great and cheap option.
I think you made mistake, 2cm thick ALU plate is ... I don't know, 30kg?
So 1150 x 70 mm ALU plate would cool 7W of heat? 115 x 7 = 805 / 110 = 7.3 ... to what temperature? Under 40°C?
So your math in previous post is wrong. So, how much heat can 1150 x 1150 x 2 mm plate cool? 25W? That's nothing. As I know, thickness is not important here, as much as surface.Lol, yeah! 2mm...
The 110cm/heatwatt formula is calculated with ~50°C target temperature in mind.
I recently added the strips and raised it from 120w COB(6) to 150w Strip/COB. The strips themselves already have a larger surface than COB's. I would distribute at least 10 Citi1212 on such a large plate, gen.2 / CRI90 are available for ~ 8 €, gen.2 you get for ~ 10 € / pcs. Look around the junkyard, where you'll find mountains of aluminum and you'll never find it cheaper.
I once found eight massive 200x 250x 40mm heatsinks, 3.25kg /ea. and paid just $ 90. With HeatsinkUSA I would have only got 3 for it.
You didn't answer me.But why not Bridgelux EBgen.2 strips? These strips neeup. no heatsink @1050mA, only a light weight frame to mount them on. Each strip need ~40v@1050mA(~42w) and puts out ~170lm/w in 3500°k. 5-6 4ft. strips(14/ea.) and a HLG-240H-42A would be cheaper because you don:t need any kind of heatsink. Such a frame with strips would not be half as heavy and is much easier to hang up.
With strips you profit from better spread and deeper penetration and they can hang much closer to the canopy, which means you can dimm the light down and still get the same intensity on canopy level.
If my lamp is 24" above the canopy I need ~300w for even 50klx measurment, at 16" I get the same intensity from only 250w.
Strips also allows to make something like a suncloark(horizontal and vertikal aligned strips, google it for more info), which in really efficient.
Digikey ships to germany with no customs but prices on their website are without VAT. That's common praxis and it's the same with the tme.eu drivers. It's always the same. You need to pay 19% more because of MwSt. or you pay the same in customs when shipped from outside of europe.
@diyled also sells strips in his shop and they ship from GB. If they use GLS for shipping, there are no customs to pay. GLS is a europian parcel service and inside the EU there in no reason for custom control. Seedbanks and reseller like Bushdoctor.at use GLS for this reason.