Multiple Servos Connected to a Servo Driver

Hello everyone,

I need some help with a project where I am making a humanoid robot. So I have planned to use 12 S9G0 micro servo motors connected to a servo driver and to the Arduino UNO board.

The problem is that I was originally going to use a 5V battery, but I did some research and some people have said about using a 12V battery? I am unclear because how much volts would each the servo motors have then if my battery was 12V?

I am new to Arduino, so apologies.

BTW, here's the servo driver that I am going to be using Overview | Adafruit PCA9685 16-Channel Servo Driver | Adafruit Learning System

Thank you :slight_smile:

12volt will fry 5volt servos.

Must use a ~5volt (4-6) power source with enough current capability for 12 servos at the same time.
For tiny SG-90 servos that means 12*0.65Amp = ~8Amp.

AA-type batteries might not be able to provide that current for long.
You could go for a bigger 12volt battery, and a 12>5volt buck converter that is capable of delivering 10Amp.
Leo..

Thank you so much for the information,

However, the servo motors won't be running simultaneously. each servo motor will be running at different times, depending on the movement of the body parts of the humanoid robot.

Before, you said that a 12V will fry the servo motors, but then at the end, you suggest to go for a bigger 12V battery.

Also, will the voltage be the same throughout the whole circuit? Is my circuit a parallel one? I have provided the diagram below.

zvrm_17:
However, the servo motors won't be running simultaneously. each servo motor will be running at different times, depending on the movement of the body parts of the humanoid robot.

On bootup, all servos go to the programmed rest position at the same time.
You can normally spread startup time of each servo by attaching them one by one with some time in between,
but I don't think you can do that with a PCA9685 breakout board.
And servos constantly try to keep their position when under load.
Most servo problems posted here are power supply related.

zvrm_17:
Before, you said that a 12V will fry the servo motors, but then at the end, you suggest to go for a bigger 12V battery.

AND a 12>5volt buck converter.

Maybe you should first try to finish your project with a mains powered 5volt/10A supply, before moving to battery power.
Leo..

Hobbyking makes some applicable SBECs that will convert your 12v to 5v and are able to provide the current you need.

I used this 20A SBEC to run 18 larger servos and it worked well. It provided enough current for all 18 servos to initialize, and typically only 3 servos were operating near maximum at a time.