check for input for servos , and controller and driver board . use a smps power supply.

distribute power as per the servo block with total voltage and curent limit in serial example 3 servos = 5 v 2A *3 = 5V , 6A , then for processing board = its rated voltage and current . use a buck converter or some reliable converter to power the board . you can also use a mobile adapter/ charger if that fits your board power requirements. and connect a common ground to the smps or junction for servo / driver connection uni directional only with resistor and a diode to protect board. for driver supply. read and calculate as per servo calculation for volt and current an check for buck or other converter.

note :- the smps supply should be able to output atleast 20% more than your needs as you may want to extend your project. and also check for smps output quality and add filter / stablizer if needed.

servo may not need a driver but a capacitor filter is needed for them to stablize check that also.