Inductive transducer responsive to displacement along a path

Claim 1

An inductive displacement transducer suitable for indicating the displacement of the fuel injection control rod in an internal combustion engine and utilizing semi-differential variable inductance unit including an adjustable comparison inductor and a variable inductor having a short-circuiting ring movable by a member of which the displacement along a path is to be measured, and further comprising the improvement which consists in that: both said comparison inductor and said variable inductor of said semi-differential inductance unit are constituted of a first and a second coil magnetically coupled to each other; one of said coils of said variable inductor of said unit is connected in series with a first coil of said comparison inductor of said unit and the series combination thereof is connected between the output terminal of an amplitude-regulated oscillator and a reference potential such as ground potential; the second of said coils of said comparison inductor is connected to supply a signal to a first rectifier circuit (G1) that provides an amplitude regulating magnitude to said oscillator (Os) and the second of said coils of said variable unductor of said unit is connected to provide a signal to a second rectifying circuit (G2) having an output for furnishing an electrical signal representative of the ratio of the respective inductances (L1, L2) of said variable and comparison inductors.