Right Power Supply to power servo shield

Hello Everyone, I’ve recently ordered a Arduino UNO R3 and an Adafruit 16-Channel 12-bit PWM/Servo Shield to drive about 5 Hobby King 15328A servos. But my only issue is im not quite sure what power supply to run the shield off from its terminal block.

i was looking at a 5V 10A Switching Power Supply from Adafruit but i’m not confident just want to make sure.

Thank you!

Hi Aidan, I had a look at the page for the HobbyKing HK15328A, and I see current is not published for this unit.

I did a bit of Googling around and Pololu explains:

A standard servo will have a stall current around one amp, a micro servo will need a few hundred milliamps, and a giant servo can draw ten amps or more.

I went looking for some general information about servos to work out what size your servo is. MotionRC has a general size chart for servos and it seems yours is a Standard sized servo.

Putting the above info together: if you put all five servos into a stall condition (pushing against something with their maximum force) maximum current would be around 5A. So power it from a 4.8 - 6.0V 5A (or more) power supply and see how it goes. Of course if the servos are unlikely to stall at the same time you may only need 1-2A.

Don’t forget you can wire the servo power supply to an analogue input on the Arduino to measure voltage. You’ll need to use a voltage divider circuit to make sure you don’t put more than 5V on the input. You can then deliberately stall one or more servos and measure the voltage. If it’s dropping below the nominal voltage, it’s overloaded.

Good luck with your project! Let us know how it goes?

  • Chris