Analytical study of a linear variable differential transformer transducer

A theory to explain the functioning of a linear variable differential transformer (LVDT) transducer has been developed in this work. By using the magnetic vector potential A in cylindrical coordinates for a thin circular conductor carrying a current I, the expressions for the self‐ and mutual inductances involved in the theory were obtained. Kirchhoff laws for alternating currents were used to obtain an expression for the transfer function or gain ∥vo/vi∥ of the transducer. Then, the variation of gain with displacement θ at a fixed frequency, as well as the dependence of gain with frequency at a fixed displacement θ are examined. Finally, it is concluded that the results here found correspond to a self‐compensated LVDT. © 1995 American Institute of Physics.