Servo Motors, Arduino + Power Sources


I am controlling a large number of servo motors from a couple of arduino boards, and am interested in powering the motors from a separate source other than the Arduino’s 5V so I can have a lot of them operating without drawing too much current and lessening the power to each motor. The arduino still send the control (pulse) signal to the motors.

The problem I am having is that when I test separate power source to a servo motor (a power supply w/5V voltage regular) on a bread board and plug the control into the Arduino, the voltage regulator gets VERY hot (like, something is wrong hot). I’ve added a few capacitors, and it doesn’t fix the problem.

Do the control and power source for a servo motor have to be from the same source?

Is this an issue with the external servo power source is adding a continuous 5V to the pulse signal (which i assume is pulsing voltage) and this is causing it to overload?

Is there a way around this, or do the motors have to have both power and control signals from the Arduino?


Do not connect the power supplies +ve line to the Arduino only the -ve to the Arduino ground.

Take the servo power from the external supply and the signal from the Arduino.

do the motors have to have both power and control signals from the Arduino?

The motors should take power from a large external power supply and control signals from the Arduino. The negative terminal (0V, Ground) of the power supply must be connected to the Ground pin of the Arduino.

How many servos do you want to control? I could use some testing on a new library that supports up to 12 servos on a standard Arduino board, and up to 48 with the Arduino Mega board.