A circuit configured to sense the driving current of a motor, the circuit comprising: a driver configured to generate a driving current for a motor; a first current sensor configured to sense the driving current thereby forming a first sensed current; a second current sensor configured to sense the driving current thereby forming a second sensed current, the second current sensor being more thermally stable than the first current sensor; a comparator configured to compare the first sensed current and the second sensed current below a threshold frequency to generate a thermal calibration output; and a calibrator configured to calibrate the first sensed current by the thermal calibration output to form a sensed driving current.

Embodiments disclosed herein include a sensor. In an embodiment, the sensor comprises a board, wherein an aperture is formed through the board, a current loop winding through the board around the aperture, and a voltage ring around the aperture and within an inner perimeter of the current loop, wherein the voltage ring comprises an interior ring, an insulator ring around the interior ring, and an exterior ring around the insulator ring.

Some embodiments describe a DC meter system that can be placed in-line between a power source and an electrical load. In some embodiments, the DC meter system includes a DC meter that has multiple inputs for receiving electricity from multiple power sources. In some embodiments, the DC meter has one or more outputs, each capable of delivering electricity to a different electrical load. In some embodiments, the DC meter can combine electricity from two or more of the multiple inputs into one of the outputs. In some embodiments, the DC meter has a controller that can enable a user to deliver electricity from a particular input to a particular output. In some embodiments, the DC meter is configured to enable transition of electricity between an input and an output in a bi-directional manner. In some embodiments, the DC meter can record an amount of electricity transmitted in either direction.

This application discloses a measurement apparatus that does not use a femtosecond laser light source and a delay stage. The measurement apparatus mixes a first laser light from a first CW laser light source and a second laser light from a second CW laser light source to generate an interference light having a beat in a range from GHz to THz and demultiplexes the interference light into a pump light and a probe light. A generating photoconductive antenna is irradiated with the pump light, and a detecting photoconductive antenna is irradiated with the probe light. A current value of an electromagnetic wave propagating through a waveguide connecting the generating photoconductive antenna and the detecting photoconductive antenna is measured using a current system connected to the detecting photoconductive antenna.

The present invention provides an occupant classification apparatus for a vehicle. The occupant classification apparatus for a vehicle includes a sensor mat that is mounted on each seat in the vehicle to sense objects disposed on the seats. An impedance measurer is configured to measure a current based on impedance of the object using the sensor mat A controller is configured to analyze the current measured by the impedance measurer and estimate the object that corresponds to the analyzed result.

A lock-in amplifier includes a clock signal generator configured to generate a first demodulation clock signal and a second demodulation clock signal having a phase difference of 90 degrees and a same demodulation frequency; and a detector configured to, based on an input signal, the first demodulation clock signal, and the second demodulation clock signal, provide an offset voltage corresponding to an offset of the lock-in amplifier in a first operation mode, and provide a first output voltage and a second output voltage, each of which correspond to a demodulation frequency component of the input signal in a second operation mode.

Apparatus and methods for detecting stray voltage anomalies in electric fields are provided herein. In some embodiments, an apparatus for detecting an electrical field may comprise: at least one sensor probe for generating data corresponding to an electrical field detected by the at least one sensor probe, wherein the at least one sensor probe comprises at least one electrode; a processor, coupled to the at least one sensor probe, for analyzing the data to identify a voltage anomaly in the electric field; and an indicator, coupled to the processor, for alerting a user to a presence of the voltage anomaly in the electric field.

Apparatus and methods for detecting stray voltage anomalies in electric fields are provided herein. In some embodiments, an apparatus for detecting an electrical field may comprise: at least one sensor probe for generating data corresponding to an electrical field detected by the at least one sensor probe, wherein the at least one sensor probe comprises at least one electrode; a processor, coupled to the at least one sensor probe, for analyzing the data to identify a voltage anomaly in the electric field; and an indicator, coupled to the processor, for alerting a user to a presence of the voltage anomaly in the electric field.

The present invention relates to power conversion systems, specifically, it relates to a device for detecting the DC voltage rectified from the AC power supply voltage in an AC-DC converter, primarily used to determine whether the DC input voltage is under a brown-out level and to monitor whether the AC power supply is removed and to discharge the residue DC voltage generated in a high frequency filter capacitor, which is used to filter high frequency noise signals of the AC power supply, during the removal of the AC power.

A measuring apparatus is provided for electrical signals. The measuring apparatus includes an analog-to-digital (A/D) converter configured to A/D-convert an analog signal to be measured, and an integrator configured to perform integration time processing for a plurality of digital values output from the A/D converter based on an integration time. The integrator is configured to output a plurality of measured values obtained by the integration time processing. A noise level calculation unit is configured to calculate a noise level of the analog signal to be measured from the plurality of measured values obtained by the integration time processing, and a display unit is configured to display noise levels corresponding to a plurality of integration times.