I need to power an Arduino and four 4.5v-9v 2A Li-ion charger boards with a single wall adapter. Not wanting a shared circuit between the chargers, I'm thinking maybe a 12v 600mA (or something..) plug with a buck converter for each charger and powering the Arduino directly from the plug. I have no clue how to calculate how much amperage the buck converter will output given the input/output voltage range possible. This one states it only ouputs 1A when stepped down to 5v from 12v
Need each charger circuit to have 2A available whenever needed but cant figure out which buck converter/voltages/input current I need?
Im not fussed about exact voltages once its within range of the Ardunio (5v-12v) and chargers (4.5v-9v) of course.
Edit: According to this and taking into consideration 80% efficiency, it seems my application would need a 12v plug that delivers at least 1.04A for a buck converter to step down to 5v 2A output. Does this seem correct? If it is then I guess the only question left is will any old buck converter that is rated for 2Amp or more be suitable?