E/U core linear variable differential transformer for precise displacement measurement

An array of LVDT sensors measuring displacements between surfaces comprising:

• a plurality of E cores supported on the base of one of said surfaces, said E cores being evenly spaced in a linear array, said E cores having first, second and third pole pieces facing another of said surfaces, said first and third pole pieces each supporting a secondary winding, said secondary windings of an E core being differentially connected together, said second pole piece supporting a primary winding connected to a source of alternating current;
• a plurality of pairs of U cores, supported on said another surface, each U core having a pair of pole pieces facing said E core pole pieces, forming an air gap therewith, said pairs of U cores being spaced so that at least one pair of U cores is positioned under one of said E cores as said surfaces are linearly displaced with respect to each other;
• and,
• circuit means connected to each of the differentially connected secondary windings, said circuit means blending signals received from each of the E cores, and providing an output signal representing one of said E cores which is providing a voltage proportional to the minute displacement of one pair of U cores.