Parallel Driving (4) XR-E

[matt304]

I have a portable bench light I am building. It uses larger lithium battery packs made for remote control planes. Depending on the final voltage requirement of the driver, I could run anywhere from a 3.7V 5000mAH to an 11.1V 3300mAH pack.

I would like to use (4) XR-E Q5-WC emitters in a parallel configuration. I would like to drive each LED at 1 to 1.2A.

I am looking for a driver that would be small and cheap to drive all four emitters.

Have any ideas? I guess it would need 4 to 4.8A total to parallel drive them.

If it would make more sense, I could use very small drivers inside each of the (4) light heads, which are limited to about 0.60" diameter inside; one driver for each emitter that is. Or I could use a single driver mounted to the assembly somewhere else.

Thanks for any help with this.

 

[deadrx7conv]

Diminishing lumen returns as you increase power so I would think that you would be better off running an XP-G at those power levels.
http://www.cree.com/products/xlamp7090_xre.asp

http://www.dealextreme.com/p/18v-5w-cree-circuit-board-for-flashlights-16-8mm-5-5mm-26110
http://www.dealextreme.com/p/6v-5w-cree-circuit-board-for-flashlights-16-8mm-3-1mm-26109
http://www.dealextreme.com/p/2-7v-6v-3w-cree-circuit-board-for-flashlights-15mm-2-7mm-25518

To drive 4 LEDs in parallel at 1 to 1.2amp, you'll need a 4-4.8amp driver at the LEDs voltage(3.2?).
To drive 4 LEDs in series at 1 to 1.2amp, you'll need a 1-1.2amp driver at the LEDs voltage(4x3.2=12.8).

In parallel, if one LED burns out, your other three will divide the current, be overdriven, and self destruct.
In series, if one LED burns out, either the 3 other shut down, or continue to run.

Either use a bigger LED, or use a quality driver with your 4 LEDs in series:
http://www.taskled.com/techmaxflex.html

 

[matt304]

This is great, I am going to purchase 4 of the first driver with large voltage input range, and individually drive each one. Then I will change the emitters to the XP-G like you recommended. Thanks

Have you ever seen small sized drivers like that first one, which are also not very expensive, and put out a few amps, maybe 2-2.5 amps? I was thinking of something capable of driving the larger LEDs like SST-50 etc.

 

[shane45_1911]

Why would you want XR-E's? You will end up with 4 hotspots of light coming out of your bench light? Would you not rather have massive flood, rather than toothpicks of light?

 

[Packhorse]

Why would you want XR-E's? You will end up with 4 hotspots of light coming out of your bench light? Would you not rather have massive flood, rather than toothpicks of light?

If there are no reflectors it will be a flood of light covering about 90 degrees before the intensity drops below 50%..

For such a light its hard to look past AMC 7135 based drivers (second and third drivers in Deads list). Have a triple chip driver per LED for 1050ma. Very east to set up with a 3.7v battery pack. If you want to run a 8.4 volt pack then wire 2 LED's in series and follow "Downloads" AMC 7135 wiring schematic. If using a 11.1v pack wire 3 LED's in series.