Power Requirements for RGB LED Matrix


#1

I’ve been looking at a project using one or more of the 64x64 LED RGB matrix panels, but it’s unclear as to the 5V power requirements for the matrix.

The listing states “5V regulated power input, 4A max (all LEDs on)”, but this section appears to be based around the 32x32 matrix at 6mm pitch, not the 64x64 matrix.

Does anyone know if a 20W PSU sufficient to drive the 64x64 matrix panel, or if something beefier is needed?

Also, what would be the symptoms of an underpowered PSU would it partially work, run dim, or simply fail to operated?


#2

How a power supply reacts to an over current condition basically depends on the quality of the supply and what protection circuits it has. It may just clamp the current at the max. Or the output voltage could drop as you hit the max output current. Either way, what will likely happen is you won’t get full brightness on your LED matrix.
It could also just turn off completely, if it has a crowbar overload protection circuit. If that trips you have to turn the supply off and let it completely drain back to 0V before turning it on. Otherwise the crowbar circuit won’t reset.
Can’t help you with the other question.


#3

This data sheet for a very similar 64x64 matrix suggests 18W max. power consumption.


#4

Thanks, the datasheet is very useful; perhaps it could be attached to the listing somehow (if there’s an official one for the actual matrix being sold)?

It’s an overkill (and I’ve probably taken it too far) but have ordered a 100W PSU with two 5V output rails, since I may try to chain two displays together in the future. I should be able to monitor the draw on this to gauge the true requirements for future endeavours. :)


#5

Just be careful with big power supplies like that, making sure you use cabling that’s sufficiently thick and insulated, and that you isolate it in a suitable enclosure. We use a big one like that on our jumbotron that’s made up of 16 of those matrices, and we had Ed who is one of our engineering crew and a qualified electrician check it over before we used it.


#6

I still néed to source appropriate cable from the pihat to the matrix, but the initial run up is expected to be less than a foot in length, so hopefully won’t be a huge problem.

The plan is to enclose the psu, matrix etc in an acrylic case, dependent upon whether additional ventilation is required by the psu. Once the exact power requirements have been identified, a more suitable psu can be sourced.