How do I efficiently power my project?

[Ritwik Dhar]

I am new in the electronics field and require some guidance and help. I am building a gesture controlled robotic arm (4 servo)which is then mounted on a land bot (with 2 DC motors).The land bot is mind controlled by hacking an EEG headband. The arm and bot are running on two arduino unos.What is the most efficient way of powering my project ?

 

[AnalogKid]

What voltages and currents are required by each of the electronics assemblies, servos, motors, etc?

ak

 

[Ritwik Dhar]

servos (x4) and dc motor(x2) - 5V and 2A .
NRF24L01 tx and rx - 1.9-3.6v and 15mA
arduino uno - 5v and 0.2 mA
arduino pro mini - 3v and >0.2mA
mpu6050- 3.3v and 0.14 mA

 

[AnalogKid]

Most efficient is one 5 V 15 A power supply with heavy filtering for the motor outputs, heavy filtering for the electronics outputs, and a 5 V - 3.3 V regulator.

Mixing a 60 W of DC motors with a 0.1 W of uC is not a good idea; you should avoid it if you can. That means two 5 V power supplies, a big one for the motors and a small one for the electronics; plus a 5 V - 3.3 V regulator. The total 3.3 V current is so low that I don't think the added complexity of a switching buck regulator is going to get you much more efficiency, and it will definitely make more noise.

ak