Differential Transformer:

Another type of inductance transducer, described within above Figure, utilizes two coils wound on a single tube and is generally referred to as a Differential Transformer.

Figure: Differential Transformer

The primary coil is wound around the middle of the tube.  The secondary coil is separated along with one half wound around each end of the tube.  Every end is wound in the opposite direction that causes the voltages induced to oppose one another.  A core, positioned through a pressure element, is movable inside the tube. Whenever the core is in the lower position, the lower half of the secondary coil gives the outcome. While the core is within the upper position, the upper half of the secondary coil gives the outcome. The magnitude and direction of the outcome depends on the amount the core is displaced from its middle position.  While the core is in the mid-position, there is no secondary outcome.