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 a rotation angle detection device for detecting a rotation angle and a rotation speed of a motor generator by using a resolver, a resolver detection accuracy is improved by raising the amplitude or frequency of an excitation signal when the motor generator is performing a driving operation. Furthermore, by reducing the amplitude or frequency of the excitation signal when the motor generator is not performing a driving operation, it is possible to suppress the amount of heat generated by the excitation circuit and the resolver, while maintaining a resolver detection accuracy that enables information about the rotation speed of the motor generator to be obtained.

An apparatus for generating a resolver excitation signal and a vehicle including the same are provided. The apparatus includes an input portion that is configured to receive an input signal and a current amplifier that is configured to generate an output signal by amplifying the input signal and that has a circuit protector that protects a circuit from an overcurrent. An output portion is configured to output the output signal. Additionally, the circuit protector includes a first transistor that has an emitter connected to the output portion, a second transistor that has a collector connected to the output portion and a base connected to a base of the first transistor and a rectifier connected to a base of the first transistor and the base of the second transistor.

A method for monitoring a resolver having first and second winding assemblies, the first winding assembly having a sine winding and a cosine winding arranged so that when inductive coupling between the sine winding and the second winding assembly is zero, inductive coupling between the cosine winding and the second winding assembly is at a maximum, and when inductive coupling between the cosine winding and the second winding assembly is zero, inductive coupling between the sine winding and the second winding assembly is at a maximum, the method including obtaining a master amount of total inductive coupling between the first and second winding assemblies of the resolver; obtaining a current amount of total inductive coupling at a current instant in time; and deciding that the resolver is defective when a difference between the current amount and the master amount exceeds a predetermined threshold.

A displacement sensor for a power tool includes: a stator element, having a first conductive pattern, and a rotor element, having a second conductive pattern, for relative movement along a measurement path, wherein the first and second conductive patterns are mutually inductively coupled so that the first conductive pattern receives an excitation signal and the second conductive pattern generates an intermediate signal. The intermediate signal indicates relative displacement between the stator and rotor elements, wherein the excitation signal is a constant amplitude high-frequency signal. A signal processor circuit receives and processes a single phase receive signal corresponding to the intermediate signal to provide an output signal indicating relative displacement between the rotor and stator elements. A phase detector circuit processes the single phase receive signal to detect a phase difference between the receive signal and a reference signal corresponding to the excitation signal to provide the output signal.

A position measurement system including a material measure and a scanning device movable relative to one another with respect to a measurement direction. The material measure has a plurality of markings which are arranged in a row with respect to the measurement direction, wherein the scanning device includes a transmitter winding arrangement. Multiple receiver coils are provided which are arranged in a row with respect to the measurement direction. The inductive coupling between the transmitter winding arrangement and the receiver coils is a function of the position of the scanning device with respect to the material measure. The transmitter winding arrangement defines multiple separate transmitter areas which are arranged in a row with respect to the measurement direction. A maximum of one single receiver coil is situated in each of the transmitter areas. At least one switching means is provided via which the two adjacent receiver coils are differentially interconnectable.

A method for producing a rotational angle sensor unit comprising a housing unit, which has a housing that defines a housing volume. A rotor is at least partly positioned in the housing volume, and a gearwheel adapted to be rotated by the rotor. A printed circuit board is positioned in the housing volume. The method has the following steps: providing an aligning structure, positioning the aligning structure on the housing unit, and positioning the printed circuit board in the housing volume using a positioning unit. The positioning unit is moved relative to the position of the aligning structure on the housing unit in order to position the printed circuit board in a specified position relative to the rotor. A system, a housing, and a printed circuit board are also provided for producing the rotational angle sensor unit.

A receiver coil of an inductive angular position sensor can have circuit features that become smaller than reasonable for high resolution measurement designs. This is especially true when multiple receiver coils are used, such as in a three-phase configuration, and when each of the multiple receiver coils is in a twisted loop configuration. The disclosed inductive angular position sensor utilizes different spatial frequencies for a rotor coil and the receiver coils. For example, the spatial frequency of the receiver coils may be kept smaller than the rotor coil. In this condition, the fundamental frequency of the angular position sensor is shifted to the least common multiple of the spatial frequencies, making the angular resolution of the inductive angular position sensor high, while the circuit features of the receiver coils are maintained at a reasonable size.

A position detecting system includes: a capsule medical device having therein a magnetic field generation coil for generating a magnetic field; detection coils configured to detect the magnetic field generated by the magnetic field generation coil, and to output detection signals; at least one reference coil configured to detect a magnetic field and to output a detection signal, and arranged at a position where a signal-to-noise ratio to the magnetic field generated by the magnetic field generation coil is smaller than a signal-to-noise ratio in each of the detection signals detected by the detection coils; and a magnetic field correction unit configured to correct magnetic field detection values based on the detection signals respectively output from the detection coils, using at least one reference magnetic field detection value that is a detection value of the magnetic field based on the detection signal output from the at least one reference coil.

A variable valve device for an internal combustion engine for varying operating characteristics of engine valves by changing a relative rotational phase of a camshaft to a timing sprocket has an electric motor that rotates the camshaft relatively to the timing sprocket, a cover member provided to cover a front end section of the electric motor, and an angle sensor that detects a rotational angle position of a motor output shaft. The angle sensor includes a detected unit provided inside of a top end section of the motor output shaft and a detecting unit provided on the cover member so as to be opposed to the detected unit through a minute clearance. A metal disk-shaped reinforcing plate is molded and fixed inside of a cover main body of the cover member mainly formed of a synthetic resin material, thus enhancing the entire rigidity of the cover main body.