I am trying to figure out how much three solenoids will require.
I am using a MOSFET to control the solenoids ( Mini Push-Pull Solenoid - 5V : ID 2776 : $4.95 : Adafruit Industries, Unique & fun DIY electronics and kits ) from the arduino but I need a separate power supply for the solenoids.
Was looking at something like this:
On top of that, could I also provide power to the arduino via USB to mains? Or should I use the barrel DC connector?