The present disclosure relates to a sensor comprising a resonant circuit, a driver, a drive enable circuit, a sample-and-hold-circuit, and a measurement circuit. The resonant circuit comprises a passive load and an active circuit, at least one of the active circuit and passive load tuned to resonate at a resonant frequency. The driver is configured to drive the active circuit to output an RF signal at the resonant frequency, while the drive enable circuit generates a control signal to enable and disable the driver. The sample-and-hold circuit is configured to hold a peak level of the amplitude signal, and the measurement circuit detects a relative position and/or movement between the passive load and active circuit based on the held peak level. Corresponding systems, methods and apparatus are also described.

In one embodiment, an inductive/LC sensor device includes: an energy storage device for accumulating excitation energy, an LC sensor configured to oscillate using energy accumulated in the energy storage device and transferred to the LC sensor, an energy detector for detecting the energy accumulated in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector for terminating accumulating excitation energy in the energy storage device when the charge threshold is detected having been reached by the energy detector.

A safety switch (1) having a reading head (2) and an actuator (3) having a transponder (4) and being movable relative to the reading head (2). Encoded signals of the transponder (4) are detectable by means of the reading head (2). As a means for detecting encoded signals, the reading head (2) has a resonant circuit (6) controlled by a processor unit, with the distance between the actuator (3) and reading head (2) being determined by means of an amplitude evaluation of the signals of the transponder (4) detected with the resonant circuit (6). Control signals are generated as a function of the distance signals thus determined.

A system may include a resistive-inductive-capacitive sensor, a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor, and a filter communicatively coupled to the measurement circuit. The measurement circuit may be 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. The filter may be configured to isolate changes to the displacement which are significantly slower than an expected change to the displacement in response to a human interaction with the mechanical member.

A target device for use with a switch device of a proximity switch has a wireless receiver means (6) for detecting and receiving a first pulsating signal (A) with a first carrier frequency (f1) from a nearby transmitter module (5), demodulating (6, 7) the received signal, and if a superimposed digital signal is present, inverting (9, 10, C4, and Q1) the superimposed received digital signal or, if the superimposed digital signal is absent, passing the existing energy through (10). The target device also has a wireless transmitter means (12) for modulating and sending the inverted pulse train if this exists by the second carrier frequency (f2) to the receiver switch unit (13). Additionally, the target comprises functionality to transmit the carrier frequency (f2) continuous and unmodulated where a continuous and unmodulated carrier frequency (f1) is present. However, upon existence of the pulsating signal only one of the receiver (6) and the transmitter (12) receives or transmits a signal at a given time.

A touch-sensitive glass barrier has a conductive coil affixed to the first side of a glass barrier, a capacitor connected to the conductive coil to form a resonator, and an inductance-to-digital converter (LDC) connected to drive an alternating current through the resonator. The LDC determines whether a conductive target has touched the second side of the glass barrier at a point opposite the conductive coil; and responsive to determining that the conductive target has touched the second side of the glass barrier at the point, provides a signal.

A magnetic field sensing apparatus including a magnetic flux concentrator and a plurality of magnetoresistance units is provided. The magnetic flux concentrator has a top surface, a bottom surface opposite to the top surface, and a plurality of side surfaces connecting the top surface and the bottom surface. The magnetoresistance units are respectively disposed beside the side surfaces. The magnetoresistance units are electrically connected to form at least one kind of Wheatstone full bridge in three different periods, so as to measure magnetic field components in three different directions, respectively, and to cause the at least one kind of Wheatstone full bridge to output three signals corresponding to the magnetic field components in the three different directions, respectively.

In one embodiment, an inductive/LC sensor device includes: an energy storage device for accumulating excitation energy, an LC sensor configured to oscillate using energy accumulated in the energy storage device and transferred to the LC sensor, an energy detector for detecting the energy accumulated in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector for terminating accumulating excitation energy in the energy storage device when the charge threshold is detected having been reached by the energy detector.

A touch-sensitive glass barrier has a conductive coil affixed to the first side of a glass barrier, a capacitor connected to the conductive coil to form a resonator, and an inductance-to-digital converter (LDC) connected to drive an alternating current through the resonator. The LDC determines whether a conductive target has touched the second side of the glass barrier at a point opposite the conductive coil; and responsive to determining that the conductive target has touched the second side of the glass barrier at the point, provides a signal.

A device for detecting a user's intention to lock or unlock a motor vehicle door, integrated into a handle (10) and consisting of a casing (B) includes a first part (52), elastically deformable along a predetermined axis (Y-Y), with an area (50) of contact with the handle, a printed circuit (80), a voltage source (Vcc), and a contact detection element (100) including: a non-magnetic metal target (40) which moves along the predetermined axis, a coil (20), and a capacitance (C1), forming an oscillating circuit, elements (M1) for adjusting the frequency of the circuit, a prestressed compressible element (30), located between the target and the coil, elements (51) for transmitting a movement of the first part to the target, elements (M2) for measuring an inductance (L) of the coil, elements (M3) for comparison between the measured inductance and a predetermined threshold value of inductance (L.sub.s), and control elements (60).