Hi - can anybody explain how hobby servo motors work? I'm guessing it's something like this: during the high phase of the PWM pulse some sort of capacitor or something is charged, and then the voltage across that cap is compared to the voltage across the center terminal of the pot. Then the control circuitry sends out a current proportional to the difference between those two voltages until the next PWM pulse is received.
Or something like that.
Anybody know?
The reason I ask is simple: I am trying to measure the current going through my servo motors (Hitec HS-81MGs) as a very basic force feedback system. What I'm not sure about is when I should be measuring current across them. Right now I just have an RC filter across them that is averaging the signal somewhat - but it is not a perfect solution. Any suggestions as to when I should measure current to get the optimal force feedback, with respect to either the start or the end of the PWM pulse?
Thanks!
-Mike