Newby question on powering

Other Hardware Motors, Mechanics, Power and CNC
1

I am looking at a project creating a led Matrix together with some 4 inch larger 7-segment displays (using MAX7219).
The led's require 5V, the 7-segments 10V. I estimate max. total power consumption of all componentes to be 5A.

I do not need to be mobile, so a wall-wart with sufficient power is fine. If I purchase a 10V-5A power source, how do I feed the Arduino, the leds (5V) and the 7-segment displays (10V) in a correct way? I was thinking about following:

  • Connect the 10V from the power source to Arduino power
  • Connect the Arduino 5V pin to a 5V rail to feed the leds
  • Connect the 10V from the power source to a seperate 10V rail to feed the 7-segment displays

Are there better ways of doing this? If 5A is consumed by the LED's, will this harm the Arduino?

2

Get a 10V a supply and a 5V switching regulator.
Arduino 5V regulator can only supply a few hundred mA before overheating.
MAX7219 cannot control 10V displays. Best bet there is common anode displays with four TPIC6B595 to sink current from cathodes.

3

If the Arduino + LED consumption is low enough a single USB charger could power
both, and a separate 10V supply would then just do the 7-segment.

Depends on the relative costs of various options, cheap USB supplies are easily
sourced.

4

Thanks for the advise and options. So even for getting the right power to the right components there is a lot to learn :slight_smile: