The minimum duty cycle of width 1 ms is subtending 0 degrees.As per the above diagram, we may see, that The angular rotation of the servo motor depends on the clock’s duty cycle (ON Period). The error when applied back to the DC motor armature results in amplification of the input, and the motor moves with a more powerful speed. The voltage produced is again fed back to the control unit and the comparator finds the error as ERROR= Output voltage (feedback signal)- Input Voltage(fed signal). Here we are describing the servo motor working. Corresponding to the angular velocity of the motor shaft and gear mechanism, voltage is produced as a feedback signal which is sensed using a sensing device.
As a result, the motor rotates as per the voltage applied through the pulses.PLC motion controller from the control unit generates the electric pulses, which is fed to the DC Motor.*Servo Motor = DC Motor + Gear Assembly + Position sensing device* The motors have two types of coils inside namely the Stator armature coil and the Rotor armature coil. Synchronous or Asynchronous servo motors are categorized based on “types of magnetic field “ produced inside armature.Brushed motors are simple and easy to rotate with noise whereas brushless are used to achieve higher efficiency with less noise. Brushed or Brushless servo motors are categorized based on “types of commutators “, they are designed of.AC servo motors withstand higher currents and are mostly used where high repetition and precision are required whereas, DC servo is mostly used to carry fewer loads. AC or DC servo motors are categorized based on the “types of currents “, they operate.It has three types of classifications – AC or DC servo motors, Brushed or Brushless motors, and Synchronous or Asynchronous motors.It is controlled by analog and digital types of electric signals.Note: Servo Motors are nothing but a regular DC motor coupled with a sensor to provide positional feedback or feedback signal.