I'm trying to control a HS-7940TH servo powered with 7.2V battery (from Pololu) using a 5V Arduino PWM output. However, the servo doesn't seem to turn on or attempt to move when I power the servo with 7.2V but does work when it is powered via the Arduino's on board 5V regulator. See image below...
The setup on the left works fine. The servo turns on and performs as expected.
The setup on the right does not work for some reason. The servo does not even attempt to move and the servo arm can be moved freely. Note: the servo is not under load. The Arduino isn't resetting so I don't think it's an issue with the servo pulling too much current.
Is the 2.2V difference between the servo voltage and the control voltage too much? Would reducing the servo voltage to 6V work or am I stuck with 5V?
I want to power the servo with a higher voltage than 5V so that I can take advantage of the increased servo speed at those voltages.