Lance,

A 16 x 400 x 2 LED matrix includes 12800 LEDs. 12800 x 0.020 A = 256 amps. If 50% are on at once that gives us 128 amps. Also, I assume you are not running these at 100% duty cycle. That may require that you drive the LEDs with more current to get the desired brightness. If you run at less than 100% duty cycle and leave the drive current as is, that would reduce your total current requirements. Ex. 10% * 128 = 12.8 amps. That may make your LEDs too dim though. I think the first thing you must decide is how you will multiplex these LEDs and what drive current is necessary at that duty cycle to achieve the desired brightness. This starts to get into optical theory(persistance of vision, peak intensity) which is not my area. I usually just experiment with different duty cycles and drive currents until I reach a compromise.

We use low current LEDs. 2 mA. Can you get low current LEDs that meet your requirements?

I assume that the big screens use more efficient LEDs, otherwise they would need their own power plant.

Cory Spackman