Systems and methods for measuring an operating current and an operating voltage of an inductive proximity sensor in an improved manner. The proposed method is to measure and process the sensing parameters in a ratiometric way. A proximity sensing electronics unit receives an input signal from a proximity sensor that was derived by dividing the sensor's current by the sensor's supply voltage which produces that operating current. The division result, i.e., the quotient, is properly scaled to represent the sensor's state. The circuitry ratiometrically determines its operation status by eliminating common mode effects and variations of sensor state thresholds, allowing additional sensing parameters and health status to be measured and monitored without extending the operational range of the sensor.

A control apparatus includes: a data acquisition part that acquires correction data indicating a content regarding a correction process which corrects an error of an angle at which a rotation angle sensor that measures a rotation angle of a rotor included in an electric motor is attached; a determination part that determines, based on the correction data, whether or not the correction process has been performed; and a control method determination part that determines, in a case where it is determined that the correction process has not been performed, that an inverter which supplies an AC current to the electric motor is controlled under a pulse-width modulation control.

A system may include a resistive-inductive-capacitive sensor, a driver configured to drive the resistive-inductive-capacitive sensor at a driving frequency, and a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure phase information associated with the resistive-inductive-capacitive sensor and based on the phase information, determine a displacement of a mechanical member relative to the resistive-inductive-capacitive sensor, wherein the displacement of the mechanical member causes a change in an impedance of the resistive-inductive-capacitive sensor.

The invention relates to a method for measuring the armature position of a solenoid having a coil with a movable armature, constructed as a bistable linear magnet and activated in a switched mode by means of pulse width modulation, wherein the depth of the current peaks at the solenoid is measured as a measure of the inductance and the position of the movable armature.

An apparatus for sensing a rotating body includes a cylindrical supporting member being connected to a rotating shaft, a unit to be detected including a first pattern portion provided in a first height region of the supporting member, and the first pattern portion including first patterns extended in a rotation direction of the rotating shaft and a second pattern portion provided in a second height region of the supporting member, extended in a rotation direction of the rotating shaft, and the second pattern portion including second patterns having an angle difference with the first patterns, and a sensor module including a first sensor disposed opposite to the first pattern portion and a second sensor disposed opposite to the second pattern portion, the first patterns and the second patterns are formed of a metallic material, and each of the first sensor and the second sensor includes a sensing coil.

An inductive sensor device includes a reference sensor head that is used to adjust the characteristics of an operational sensor head that is used to detect movement of a conductive target. The reference sensor head has near it a fixed reference target that is similar to the target for which the operational sensor head detects movement, with the difference that the reference target is fixed with respect to a reference sensor coil of the reference sensor head. The reference sensor head includes a variable reference capacitor or variable reference inductor that is adjusted to maintain constant (or nearly constant) output, such as a constant (or nearly constant) resonant frequency, during operation of the sensor device. Adjustments of the variable reference element (variable capacitor or variable inductor) may be undertaken to compensate for changes in characteristics of the reference sensor due to changes in temperature, for example.

Systems and methods for measuring an operating current and an operating voltage of an inductive proximity sensor in an improved manner. The proposed method is to measure and process the sensing parameters in a ratiometric way. A proximity sensing electronics unit receives an input signal from a proximity sensor that was derived by dividing the sensor's current by the sensor's supply voltage which produces that operating current. The division result, i.e., the quotient, is properly scaled to represent the sensor's state. The circuitry ratiometrically determines its operation status by eliminating common mode effects and variations of sensor state thresholds, allowing additional sensing parameters and health status to be measured and monitored without extending the operational range of the sensor.

A touch force sensor includes a reference resonant circuit, a first resonant circuit coupled to an inductive coil, a second resonant circuit connected to a touch electrode, and further includes a determination circuit configured to obtain a first resonant frequency attributable to a first inductance formed in an inductive coil and a first resonant circuit based on a displacement between a target and the inductive coil formed by an external force input in a Z-axis direction, the second resonant frequency of a second resonant circuit attributable to a capacitance varying depending on whether a finger comes into contact with the touch electrode, and information about a reference resonant frequency.

An apparatus and method of detecting movement of a plunger of the solenoid includes detecting a peak (I.sub.PEAK) in a current signal applied to a coil of the solenoid. A predetermined threshold is added to the current signal applied to the coil of the solenoid to generate a level shifted signal. The level shifted signal and the peak signal are compared to detect movement of a plunger of the solenoid.

A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.