Little I think. The desired controller section would only consist of an Arduino Uno R3 executing a single light phase routine* via a MOSFET module wired to the LED PCB. The 3 FETs will be operated by 5V signal output from the Uno pins. At 1 pin per color this makes 3 times 40mA = 120mA at the most I would say? In practice probably less.
*) red > green > yellow > red > .... to infinity. Super basic.
That would ideally be the case. I'd like to have something like this so the whole traffic light has just 1 power plug, which in turn takes care of powering all internals (Uno, MOSFET, LED PCB):
But this would mean I need a 48V capable step-down buck converter and a 48V capable MOSFET board as that is the native voltage the LED PCB requires (and won't take less). However both such buck and FET I cannot find. I do have a switching 48V 800mA wall-socket power supply.
If I'm not mistaking, is that what you are describing as well?