What is servo motor and how does a servo motor work?

Servo motors are specially designed motors to be used in control applications and robotics. They are used for precise position and speed control at high torques. It consists of a suitable motor, position sensor and a sophisticated controller. Servo motors can be characterized according to the motor controlled by servomechanism, i.e. if DC motor is controlled using servomechanism, it is called a DC Servo motor. Thus major types of Servo motor may be – DC Servo motor AC Servo motor.

A servomechanism is basically a closed-loop system, consisting of a controlled device, controller, output sensor and feedback system. The term servomechanism most probably applies to the systems where position and speed are to be controlled.

What Is Servomechanism?

Servo motors are used to control position and speed very precisely, but in a simple case, only position may be controlled. Mechanical position of the shaft can be sensed by using a potentiometer, which is coupled with the motor shaft through gears. The current position of the shaft is converted into electrical signal by the potentiometer and then compared with the command input signal. In modern servo motors, electronic encoders or sensors are used to sense the position of the shaft. Command input is given according to the required position of the shaft. If the feedback signal differs from the given input, an error signal is generated. This error signal is then amplified and applied as the input to the motor, which causes the motor to rotate. And when the shaft reaches to the required position, error signal becomes zero, and hence the motor stays standstill holding the position.

How Does A Servo Motor Work?

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