Current Requirement for LED Display Board?

Question

HI,
I want to build an LED display board of 12(columns)x80(rows) LEDs(1000 LEDs approximately). I will be controlling this display using a microcontroller. Can anyone guide me about the current requirement for runnig this display.
Each LED requires 10mA current. How will i be able to run the display?

Answer 1

To the other guy that suggests putting all 1000 LEDs in series: Each LED has a forward voltage drop of around 0.5V, thus you'd need a 500V source to drive them all in series.



Basically you have a choice of either cycling through the rows or the columns. I would suggest you cycle through the columns since there are less of them (hence less potential for flickering).



On each cycle you would supply power to a column. Then you'd have to have 80 low-side drivers for each of the rows. At most, you'd have all 80 LEDs in a row on at any given time. Thus, your worst-case current draw for the LEDs alone would be 0.8A.

Answer 2

They'll be multiplexed so they will be "on" as long as you tell them to be. OK, all on full brightness will be 960x20mA (20A) but that situation won't occur very often unless you programme that as part of a test sequence. Consider using led matrix blocks instead of individual LEDs.

Answer 3

TOTAL CURRENT 10A.

NEED 1000 PIECES RESISTOR. SERIES ONE RESISTOR TO EACH LED FOR CURRENT LIMITING.

CONNECT 1000 PIECES OF WIRE TO THE MICRO CONTROLLER WHERE HAS 1000 OUTPUTS.

KEY IN PROGRAM TO CONTROL EACH OUTPUT LINE.

Answer 4

put all 1000 of them in series with a 10k ohm resistor.



Put all resistors in parallel.



Use a 10V source