A potentiometer displacement sensor converts mechanical displacement into a linear or arbitrary function of resistance or voltage output through a potentiometer element. Ordinary linear potentiometer and round potentiometer can be used as linear displacement sensor and angular displacement sensor respectively. However, potentiometers designed to measure displacement require a clear relationship between displacement and resistance. Connect the moving brush of the potentiometer displacement sensor to the measured object. The displacement of the object causes the resistance of the moving end of the potentiometer to change. The change in resistance reflects the magnitude of displacement, and the increase or decrease in resistance reflects the direction of displacement. The power supply voltage is usually connected to the potentiometer to convert the resistance change into a voltage output. The wire wound potentiometer has a step output characteristic, because the resistance changes with the rotation resistance when the brush moves. If a displacement sensor is used as a displacement feedback element in the servo system, excessive step voltage will cause system oscillation. Therefore, in the manufacturing process of the potentiometer, the resistance value of each turn should be reduced as much as possible. Another major disadvantage of potentiometer sensors is their ease of wear.