Rotation sensors are used for supplying electrical outputs proportional to shaft rotation. It varies in terms of electrical outputs. It measures rotating motion and angular displacement of less than one turn. It uses several different types of sensing technologies depending upon where it is applied. Potentiometers are used to identify variable resistance and measure the angle of rotation as the shaft turns. Permanent magnets mounted to the rotating sensor shaft supply a magnetic field. Variable inductance sensors include a component on the rotating sensor shaft that induces magnetic field effects on multiple stationary coils.