Systems, methods, and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally, one or more IDDQ and/or built-in-self test (BIST) circuits may be included.

A sensor processing system includes a plurality of reduction circuits. The plurality of reduction circuits correspond to a plurality of sensors on a one-to-one basis. Each of the plurality of reduction circuits is electrically connected to an output terminal of a corresponding one of the plurality of sensors to reduce a low-frequency component of a sensor output of the corresponding one of the plurality of sensors.

The implementation of modal processors, which involve the parallel combination resonant filters, may be costly for applications such as artificial reverberation that can require thousands of modes. In one embodiment, the input signal is decomposed into a plurality of subbands, the outputs of which are downsampled. In each downsampled band, resonant filters are applied at the downsampled sampling rate, and their output is upsampled and filtered to form the band output.

A method and an electric circuit arrangement for determining a branch insulation resistance and a branch leakage capacitance of a line branch to be monitored in a branched, ungrounded power supply system having active conductors and a measuring voltage fed centrally by a controllable measuring voltage source and a residual current caused by the measuring voltage being registered using a current sensor in the line branch to be monitored. The centrally supplied measuring voltage is formed over a generator period having a characteristic signal form defined via the frequency composition. By this (frequency) modulation of the measuring voltage, information is transmitted from the central feed location of the measuring voltage to the current sensor disposed in the line branch to be monitored. Based on this information, the current sensor can establish with which resistance value the coupling circuit feeds the measuring voltage in the corresponding generator period, without another communication channel being required.

A method and an electric circuit arrangement for determining a branch insulation resistance and a branch leakage capacitance of a line branch to be monitored in a branched, ungrounded power supply system having active conductors and a measuring voltage fed centrally by a controllable measuring voltage source and a residual current caused by the measuring voltage being registered using a current sensor in the line branch to be monitored. The centrally supplied measuring voltage is formed over a generator period having a characteristic signal form defined via the frequency composition. By this (frequency) modulation of the measuring voltage, information is transmitted from the central feed location of the measuring voltage to the current sensor disposed in the line branch to be monitored. Based on this information, the current sensor can establish with which resistance value the coupling circuit feeds the measuring voltage in the corresponding generator period, without another communication channel being required.

Systems, methods, and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally, one or more IDDQ and/or built-in-self test (BIST) circuits may be included.

Analysis of smart meter and/or similar data based on frequency content is disclosed. In various embodiments, for each of a plurality of resource consumption nodes a time series data including for each of a series of observation times a corresponding resource consumption data associated with that observation time is received. At least a portion of the time series data, for each of at least a subset of the plurality of resource consumption nodes, is transformed into a frequency domain. A feature set based at least in part on the resource consumption data as transformed into the frequency domain is used to detect that resource consumption data associated with a particular resource consumption node is anomalous.

A security method for monitoring an optical module and a three-dimensional sensor using the same apply electromagnetic induction to the three-dimensional sensor to monitor the optical module and a light source module. Two inductive coils corresponding to each other are arranged on the light source module and the optical module. An alternative current is inputted to one of the inductive coils and another of the inductive coils generates an inductive current. The value of the inductive current is continuously detected. When the value of the inductive current varies, the abnormality of the optical module is determined to shut down the light source module, thereby completing the security mechanism of the three-dimensional sensor.

A magnetic speed sensor may comprise a digital component configured to estimate a zero crossing event based on a plurality of sensor signal samples. The digital component may output, to a control unit, a speed signal that is based on the estimated zero crossing event.

A measuring system for performing over the air power measurements is provided. The measuring system comprises, within a single housing, a detector module, comprising a detector input, a transmitter module, comprising a transmitter output, and an antenna. The detector input and the transmitter output are at least temporarily connected. At least the transmitter output or the detector input are at least temporarily connected to the antenna.