Cree MC-E room light

[lumen_eater]

Hello every one
thats my first post here
As the title say I am planing to build an multiple MC-E room light. At the moment I am planing to use 3 or 4 MC-Es ,which leads me to my first question: are 3 or 4 leds enough to light a room with about 14m² (rough estimation)?
Also I am not sure how I should drive the leds for best efficiency. At the moment I am planing to use an 24 volts transformer in combination with a number of ZXLD1360 driver ics,but they are designed for 1A which is to much for MC-Es from what I know, so I would need to use the adjust pin of the ic ( see data sheet ) but I don't relay know how I could implement this (it needs to be driven with an very low voltage against ground but I don't know how too create this voltage in an adjustable manner without an external source).
Also I have some trouble estimating how big the heat sink would need to be (I was thinking about something this : http://www.pollin.de/shop/detail.php?pg=OA==&a=ODU3OTc2OTk=&w=MTk4OTM5&ts=0 size for 2 MC-Es without using the fan, is this realistic?) I read the other thread abut the wall light but I don't know how to apply the calculators there to an real heat sink (they are just for single plates ).
thanks in advance for your replies and excuse me for my bad English (I am from Germany)

 

[steve6690]

Hi...:welcome:

The beauty of the MC-E is that you can individually drive each die. So, you could wire it in a 2s2p configuration. Using a cc driver at 1A would mean each series pair of dies would get 500ma, which you might find is enough light for your application. Or you could wire each MC-E in 4p format and use your driver to drive two complete MC-E's in parallel. Same result...each led gets 500 ma. 700ma is the maximum recommended current for an MC-E die.
I would probably mount the led's and test the light output by powering it with a bench power supply. You can try different drive currents and heatsink configurations and then buy a suitable driver.

http://www.led-tech.de/en/LED-Contr...-for-5-8x-3W-LEDs--230V--LT-1282_118_119.html

 

[lumen_eater]

Thanks for the quick reply.:twothumbs
I wasn't sure about parallel wiring because of the fact that the leds could get different currents but I think this shouldn't be a problem within one led .now I think Im going to use a 6s2p configuration (this way I am close to 24 volts with the fV) . So what do you people think about the heat sink and how will a star pcb effect the cooling ?