What type of sensor is commonly used for position feedback in servo motors?

The commonly used sensor for position feedback in servo motors is an encoder. An encoder provides precise information regarding the position of the motor's shaft by converting it into a measurable electrical signal. This feedback is essential in applications where accurate control of movement is required, such as robotics, CNC machinery, and automation systems.

Encoders can come in various types, such as incremental and absolute, allowing for different ways to measure position and track movement. Incremental encoders provide feedback based on counted pulses as the shaft rotates, while absolute encoders maintain a distinct position value even after power loss. This capability ensures that the servo motor can accurately return to a specific position and maintain the desired speed and torque.

Other sensors listed, such as thermistors, are primarily used for temperature measurement; transducers can convert one form of energy to another but are not specifically designed for position feedback in servo systems; and inductors are typically used for their electromagnetic properties rather than for sense motion or position. Therefore, the encoder is the clear choice for position feedback in servo motors due to its accuracy and applicability in motion control systems.