Abstract: An inductive coded lock system includes an inductive lock mechanism, and a conductive key/target. The inductive lock mechanism includes multiple inductor coils and sensor circuitry. Each inductor coil is operable to project a magnetic field defining a sensing area proximate to the inductor/coil, the inductor coils being spatially arranged to define a key/target sensing area incorporating each inductor coil sensing area. The sensor circuitry drives inductor coils, and measures sensor response (such as with an inductance comparator) to a key/target inserted within the key/target sensing area, including detecting an unlock condition corresponding to a pre-defined coded lock pattern. The key/target includes active and inactive areas (such as conductive/nonconductive) corresponding spatially to the sensing areas in the key target sensing area, the active and inactive areas arranged in a pre-defined coded key pattern corresponding to the pre-defined coded lock pattern.

Abstract: A rotational sensing system is adaptable to sensing motor rotation based on eddy current sensing. An axial target surface is incorporated with the motor rotor, and includes one or more conductive target segment(s). An inductive sensor is mounted adjacent the axial target surface, and includes one or more inductive sense coil(s), such that rotor rotation rotates the target segment(s) laterally under the sense coil(s). An inductance-to-digital converter (IDC) drives sensor excitation current to project a magnetic sensing field toward the rotating axial target surface. Sensor response is characterized by successive sensor phase cycles that cycle between LMIN in which a sense coil is aligned with a target segment, and LMAX in which the sense coil is misaligned. The number of sensor phase cycles in a rotor rotation cycle corresponds to the number of target segments. The IDC converts sensor response measurements from successive sensor phase cycles into rotational data.

Abstract: Inductive position sensing uses inductance multiplication with series connected sensor coils. In one embodiment, a first sensing domain area is established in a first target plane using first and second sensor coils disposed on a longitudinal axis, on opposite sides of the first target plane and connected in series, so that a series-combined inductance is a multiple of a sum of the respective first and second coil inductances. Target position within the first sensing domain area of the first target plane is detected based on the series-combined inductance of the first and second coils, which changes as the target moves within the first sensing domain area of the first target plane. Further sensitivity can be achieved by additional coils, series connected on the same longitudinal axis, each coil pair defining a sensing area on a respective target plane intermediate the coils.

Abstract: Inductive position sensing uses inductance multiplication with series connected sensor coils. In one embodiment, a first sensing domain area is established in a first target plane using first and second sensor coils disposed on a longitudinal axis, on opposite sides of the first target plane and connected in series, so that a series-combined inductance is a multiple of a sum of the respective first and second coil inductances. Target position within the first sensing domain area of the first target plane is detected based on the series-combined inductance of the first and second coils, which changes as the target moves within the first sensing domain area of the first target plane. Further sensitivity can be achieved by additional coils, series connected on the same longitudinal axis, each coil pair defining a sensing area on a respective target plane intermediate the coils.

Abstract: A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

Abstract: Method and apparatus for measuring an entity of a magnetic field using a Hall sensor which is provided with at least one Hall plate which has a group of two pairs of terminals located at a distance from one another, an excitation signal supplied from a source to one pair of terminals and a detection signal, which forms a representation of the entity, which is tapped off from the other pair of terminals by a processing circuit. The source is a voltage source of which an impedance is negligible for use of the sensor, and the processing circuit has a negligible input impedance for tapping off me detection signal as a short-circuit current.