The question above pops up quite often these days.
An example is CCTV cameras that operate on 12v DC.
Would you choose a single 12V 10A power supply to power all of them or say 10 small ones, one for each camera?
If you let aside the fact that with a single PSU, when it fails, everything fails as opposed to the small ones where a single failure results in the loss of only one load, what would be more energy efficient?
The same goes if you have a number of arduinos operating in the same environment. Would you go for a single PSU ?
The question could be extended even further: Say you have available 12V DC but you also need 5V for some TTL logic. Would you use a DC-DC converter to get 5V from the 12V or install a seprate mains PSU for 5V ?
Or in the case of POE (Power Over Ethernet 48v) devices, would you choose separate POE injectors or go for a single POE PSU / switch?
Power supplies these days are mostly of the switching type, keeping thermal losses to the minimum.
Would it be fair to assume that a bigger PSU would be more efficient than a number of smaller ones?
Or is the difference so small that it doesn't really matter?