Large servo power requirements, how do I do this?

Hi everybody!
New here so I hope I do this right:D

I have a machine design that requires a large amount of torque so I found a ultra torque power HD 1235MG servo

(Pololu - Power HD Ultra-High-Torque, High-Voltage Digital Giant Servo HD-1235MG)

And it says the operating voltage is 6-7.4V which is higher than the 5V limited by the regulator within arduino boards/pins. What should I do in order to power this Servo while not destroying the board?

Any/All solutions welcome but definitely
Cheapest/simplest are the best as time is kind of an issue, this project is due for university in a week.

Thanks guys!

You connect the + and - from the servo directly to a good big 7.4V battery or power supply. Only the servo's signal wire is connected to a digital pin on the Arduino. Keep the power leads short and I would change the connector. Standard servo connectors are only good for 1-2A.

You then connect battery -ve also to Arduino ground and battery positive also to Arduino Vin (or the barrel connector).

You must NOT try to power the servo from the Arduino 5V pin. That will not work and will probably cause damage.


That servo is high current, probably 4 or 5A maximum under load, maybe use 2S LiPo and add a 5A fuse to protect the wiring? Worth measuring the actual current draw.

Note that a servo like that is not designed to pull its peak torque continuously, it will likely be cooked if
you do.

I have a machine design that requires a large amount of torque

I hope you have measured
or calculated it correctly - “large amount” isn’t a meaningful measurement!

Yes, calculated a high torque requirement for my machine project.

I ended up powering the arduino with the barrel connector via wall adapter.

Powered the servo with a 5V 3A Wall adaptor after splicing the end off and joining the wires with the servo’s, also wiring the adapter’s ground to the arduino ground in order to complete the full circuit.

From the link you provided,

Note: This servo can draw a lot of current (e.g. the stall current is 9 A at 7.4 V), so please make sure you use an appropriate power supply. For comparison, a typical standard-size servo might draw around an amp when straining.