Linear variable differential transformer

This device converts linear motion to a voltage signal. It consists of a primary winding, two secondary windings identical in nature and a soft iron core. Moving component is connected to the soft iron core by means of an arm. The position of the core and secondary windings are fine tuned to obtain same voltage output from each secondary winding. This is called a neutral position or null position. When core moves to the right, voltage output from one secondary coil would increase and that from other decrease. The reverse action is triggered when the core moves to the left. The amount of voltage change in secondary coils depends on the amount of movement of the core.