Hello All, I would like to power an Arduino using 5v at 3 amps. Can the Arduino handle this level of input voltage?
You can power via the 5v pin with a stable steady 5v , if that’s what your power supply provides . The current capability is irrelevant .
Though you have not specified what Arduino this is, 5 V (regulated) is the exactly correct supply voltage for it, connected to the “5V” pin and ground. You should not be using any other supply voltage although it will work somewhat at lower voltages.
Power supplies typically rate there maximum output capability. Voltage has to be the same for load and supply, currents do not. Loads typically stat how much power you need at what voltage and current. If the supply can supply the voltage, the load needs more current is OK but not voltage. You have two things to consider, the Arduino which will require less then one amp current and a power supply that will deliver 3 amps current. The load (arduino) will try to draw the current it needs and no more regardless of how much current is available. If there is not enough the power supply will react and shut down or fry. If there is more available then the power supply should supply the required power and run cooler if it is less than its rating.