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Need help understanding the signal wire.

  1. Aug 24, 2013 #1
    Need help understanding the "signal" wire.

    My servo,


    Not sure if this servo requires AC or DC power. What I really want to understand is the signal wire; specifically how changing the input value either increases or decreases the speed of the servo. I speak of input value because I do not know if the EMF or the I is changing. I'd assume that the EMF would remain constant & the change I would be responsible for change in speed of the servo.

    Perhaps it's best that I understand how a varistor works? With a varistor, the + & - leads have completed the circuit. You change the flow via screwdriver or such. You can think of turning the screwdriver as your signal, correct? How does this work? To me, it's either you complete the circuit or you don't.

    Btw, I believe the servo requires AC. I standard 9Vdc didn't work. I ran the signal to positive...
  2. jcsd
  3. Aug 24, 2013 #2


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    it requires 6V DC did you not read what it said on the page ? :wink:

    the signal wire usually is an output from the motor ... the few servo motors I have worked with produce a pulsing signal on this line that is sent back to the motor drive circuit.
    If you connected it to power you may have damaged it ??
    the 9VDC may have also damaged it ?

  4. Aug 25, 2013 #3


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    That is a standard hobby server. The control signal is a PWM input that sets the position of the arm.

    How RC Servos Works

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