Bruno28, as Rufusbduck has said one does not simply gets 5000 lumens out of some random XHP70 without at least using a hulksink plus a top-notch baseplate…
You'd just need a relatively moderate driving current for such arrays to perform nicely. Let's conservatively assume the emitters are R2 bin, that means 118 average lumens per emitter at 350mA; at 1A we get 2'4x that amount: 283'2lm/emitter × 42 emitters = 11894'4 lumens each array. Vf on each array would be close to 45V, at 3A of current.
There are some affordable desktop computer heatsink/fan combos who would (more or less) cope with such a load, especially if we reduce the emitter driving current to ≈833mA/emitter (2'5A/array), which would still get us, in theory, ≈10856 around 9912 lumens/array. Higher efficiency, and less than 110W per module.
Hope this helps.
Cheers ^:)
Original posting date: Wed, 08/31/2016 - 23:52; edited to fix a calculation error.
Would i be able to get away with no fan cooling? But i would use a nice big heat sink, probably aluminium or copper. The device I want to create will be used for night work lighting. So it need to be water resistant, and adding a fan will not allow water resistant.
Edited my previous post Bruno28, fixed the lumen output estimate for the 42 piece module driven at 2'5A (9912 lumens).
Well, I think your best bet then would be purchasing a whopping 4 modules. Driving them at baseline (binning) driving current, each one would deliver ±118×42≈4956lm, while dissipating (39'9V × 1'05A) 41'895W, something which could be reasonably well managed with a decent passive heatsink.
Enclosures? Lenses? Power sources?
Honestly, you can get AC powered ready made led lamps which are quite cost effective. Just buy a bunch of 'em:
What about those 100w cob led? They semester to produce 9000 to 10000 lumens. Two of those would be nice and floody. Simpler to design something. But not as efficient. Are they any good?
You mean those sheesh-CRI cheapass led arrays? I'm not touching on that stuff, standard sheeshy (Cree) led CRI is already enough for me.
Get some high quality (high CRI) emitters instead. Just saw the video and took a peek at the Yuji store, cool (and expensive) stuff.
0K, this may have sounded a bit off-topic but, know what? It remembered me FastTech is stocking pretty fairly priced eggsNichia 219A emitters, and I bet you my kingdom you may be able to get well under $2 price for a 3-pack if requesting a wholesale 40+pack inquiry. These leds may give you ≈180lm at 1A so, 120 leds × 180lm/led ≈ 21600lm of pleasing 92+CRI light. Of course, assembly of such a thing would require some bigass can of elbow grease…
By the way, pics of my less than $25 kitchen lamp custom retrofit:
Cool whites at the center held by ∅8×1'5mm neodymium magnets, and driven at half nominal current because of thermal reasons with a 18-36W driver (30W here). At the sides: 2×10W warm white Markerled lamps from banggood. Pleasing white combined colour temperature and better than standard Cree CRI I'd say without a doubt…
Is there a size constrain? Spreading out the emitters on the mounting plate will ease cooling concerns. All pointed one direction or ring mounted. Another way to go would be led tape spiral mounted on an aluminum tube like a barber pole.
Well this is my current prototype design I made yesterday. It would be 6 units of XHP-70 with a TIR lens that should be able to drop in the wholes and give a nice wide beam. Should be closer to 24000lm in a compact size if run at 2.4 amps. The whole body is aluminium so it will be an added bonus for heat dissipation, but there will be a 150 by 100 heatsink at the back.
Yes some active cooling seems in order here
You could go fancy and use PC water cooling parts to become a relative small part for the LEDs with a big heavy part for the radiator fans and cells.
Mount the led part on a pole that can be set to different angles to make a nice work light.
Use a metal covered shower hose (3 pieces) to guide the wires and water in and water out tube so these parts are not only protected but also looks neat.
Why wont it be able to reach the 20000lm?
3333 lumens per diode, its not even pushing the 4020lumens per Cree specs.
The problem with active cooling is the size it will make this device and also as it will need to be in rainy day, it would make this very tough to waterproof it.
It will be for the Night work we do during disaster rescue. But can also be used for 4x4 vehicles.
It is portable, only 200x100x 50mm. Quite small, not a flashlight portable.
Update: I might make it 300x100x50mm to keep it cooler and not needing active cooling. Active cooling is not an option. It needs to be water resistant.
there is no reason in using 6xXHP-70 if you are not going to use optics from this thread: Custom High power LED light bar
Several times more number of smaller leds will be better overall (lower price/lumen, much more suitable optics, wider optics configuration (from very floody to very narrow), more suitable drivers and connection configs, better heat trasfert=more simple case construction and etc.)
I have spoken to Gaggione (company of TIR lens) and will be providing me with optics similar from that project but for wide beam. They do Wide TIR lens for XHP-70. And I will get 6 of them for a wide beam of FWHM (°) 33.8 degrees - FWTM (°) 55.8 degrees.
But using XHP-50 means i will need more LEDs, more drivers, more lenses, making it more expensive to manufacture and bulkier in size.
If i run the XHP-70 at 90%, wont it still be safe for heat generation on that size device? Are there figures for the heat generation from the XHP-70 at 2.4amps 12 volts?
You can use triple or quad boards with even smaller leds. All they should be connected 3S*P. If you was going to use 6 drivers, this would be enought. Optics can be much cheaper.
2.4x13x0.8=25W from each led
Car light is not flashlight. Flashlight will make step-down after one or two minutes, while car light should be able to work for hours.
Every led config with overall 20000 lumens can have similar effincy and will require similar heatsink area, problem of multi-die leds is that this six hot points are local and you need thick case and better to use some software to make heat transfert simulation and etc.
If you use lots of small leds each is not so hot and you have less problems with heat transfert (less difference in case temperature), can use optics with small height (much less material) and etc.
Seriously? Should work great for driving 6 in-series XHPs if fed with a 24V power supply, and you can attach a potentiometer with a knob in series with the current control trimpot to achieve infinitely variable output adjustment. That's the main reason I'd use that…
This Lighting system I’m trying to create has to be efficient, small, maintenance free and self powered.
So i can’t be using liquid cooled as thats too much maintenance issues and energy consumption. Also this will not make it water resistant for rainy days. Equipment used in rescue is badly treated, its rough used, thrown around…. having this cooling system makes it too delicate. It will be thrown in the back of a truck, not a flashlight that we take good care.
