About the driver, why space constrained and in other ways limited flashlight drivers?
I'd recommend wiring the leds in series and using this new, improved version of a classic DC-DC CC/CV boost supply: 600W Power Adapter DC12~60V to 12v~80V 12A Adjustable Voltage Regulator CC-CV Laptop Charger 19v 24V Converter/Car Power Supply
A couple of these may be required as it is claimed they can only operate reliably (no additional cooling) at up to 10A of input current.
Cheers ^:)
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.
They have unbelievable low effincy. Much lower, than all leds in serial with current-limiting resistor.
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?
Especially no reason.
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…
Bruno28, you may want to check this out: Lets build a cheap GPU water cooling loop. x3 $12 chinese water blocks, will they work?
Coupled with some small car engine radiator, you would completely do away with fans. :-)
Cheers ^:)
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.