In an angular pulse generator having a movable generator part and a read head, the read head has a primary winding (W1) fed with an alternating voltage of a defined frequency and has a secondary winding (W2) whose induced secondary voltage is modulated by passing teeth and intervening gaps of the generator part. An evaluation unit evaluates the phase difference between the alternating voltage and the secondary voltage and forms a pulse for every passing tooth. A stray flux return line surrounds the primary winding (W1), so that the majority part of the primary flux linked to the primary winding (W1) flows via the stray flux return line for a large gap distance of the generator part.
An inductive sensor is comprised of a sealed housing; at least one current path disposed in the housing; means for applying current to the current path; variable low reluctance magnetic path about the current path; and means for sensing the output from the current path as a function of variations in the magnetic flux path. Alternative current path configurations include a differential transformer, comprised of a permanent magnet or one or more primary coils in conjunction with two secondary coils, or a voltage divider, comprised of two primary coils. The variable magnetic flux path includes ferromagnetic fluid disposed in the housing to a level at which all coils are at least partially submersed. Tilt or other displacement of the sensor results in a change in the amount of fluid contacting the coils and a resultant change in current output from the current path means. The change in sensed voltage is indicative of displacement and sustained output voltage is proportional to the degree of tilt of the sensor.
A sensor for measuring angular displacement of a small body comprising a sealed housing containing a differential transformer having at least two primary coils, one primary and two secondary coils, or two primary and two secondary coils, said coils being partially submerged in a ferromagnetic fluid. Upon application of an AC current to at least the primary coils of the differential transformer, the voltage across the circuit defined by the two primary or the two secondary coils is indicative of the angle of tilt of the sensor and the body to which it is attached.
A device for detecting the displacement of an object comprising a ferromagnetic material, comprises a magnetic circuit generator provided with first and a second cores made of ferromagnetic material and an excitation coil and a measurement coil. The magnetic circuit generator is connected to a detecting unit designed to detect a reluctance variation brought about in the circuit by the displacement of the object and to deduce therefrom its position. In the device, the magnetic circuit generator comprises first and second transformers with open magnetic circuit, the transformers being juxtaposed and comprise each an axis extending across their respective core, the axes extending substantially perpendicular to the path. The excitation coil comprises two coils connected in series which form the primary windings of the first and second transformers. The measurement coil comprises two coils connected in series which form the secondary windings of the first and second transformers, the primary and secondary windings being connected in opposite phase.