Automation, sensing and robotics • Power Supply and Buck Converters ?

Hi, everyone!

I am working on a robotics project and I have couple of questions regarding power supplied and buck converters.

Robot will consist of 18x servos with following specs:

• Operating Voltage Range = 4-8.4V

• Runnig current(at no load) = 160mA@8.4V

• Stall current = 3.4A@8.4V

All servos will be controlled via a Raspberry Pi 4B board.

To power all of that I need a power supply that can provide enough power to feed 18 servos + Raspberry Pi 4B board simultaneously.

In conclusion, per my calculations it means that I need:

• a power supply that can provide at least 64.2A (=18*3.4A + 3A)

• one buck converter for servos to make sure that they do not get more than 8.4V which also allows output of 64.2A

• another buck converter to make sure that Raspberry Pi 4B doesn't get more than 5V and which allows output of 3A

Three questions:

1. Are my conclusions and calculations above (regarding total amperage as well as two buck converters) correct ?

2. Even if I find such power supply (haven't found such batteries yet), would it be better to build buck converter of my own ? I looked online and couldn't find locally a buck converter that can step down to 8-9V and allow output of 64.2A.

3. I know almost nothing about PCBs. Is a buck converter something that is usually integrated into a PCB or a buck converter something that needs be separate and simply be like a link connecting power supply to a PCB ?

Thank you in advance for any help and tips!

Statistics: Posted by bestrasp — Sat Mar 08, 2025 9:28 am — Replies 1 — Views 43

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