I think you have the cart in front of the horse here, reddevil.
The current that will pass through a load depends upon the resistance of the load and the volts applied to it. It does not set itself.
Current = Volts ÷ Resistance
Power supplies are designed to supply a particular Voltage. The current rating of a power supply just gives an indication of the maximum current that it can supply. i.e. you present it with a low enough load resistance) without overheating or exploding (lol: there is usually plenty in hand). The only way to 'insist' on a certain current flowing is to set the supply volts appropriately.
Pedant Alert . If another contributor to this thread starts to talk about 'constant current supplies', it is true that they exist but it's not relevant to what you will buy in a shop or what you see in everyday life. Batteries and mains transformers are what you are referring to and they are 'Voltage Sources'.