16results about "Measurement using dc-ac conversion" patented technology

This application provides an apparatus for detecting and evaluating residual current in a DC-powered electrical system. The apparatus includes: at least two power lines to be monitored for load current; an evaluation circuit for evaluating smoothed DC residual current; and a current transformer for detecting the smoothed DC residual current, through which the monitored power lines guide the load current. At least one secondary winding of the current transformer is electrically connected to an oscillation circuit for detecting the smoothed DC residual current, and the oscillation circuit is electrically connected to the evaluation circuit for evaluating the smoothed DC residual current. Apparatus for evaluating residual current with AC components of different frequencies and pulsating DC residual current is also provided. These apparatuses include at least a second evaluation circuit electrically connected at least on the input side to the secondary winding of the current transformer. This apparatus is suitable for DC electrical systems for detecting and evaluating residual current with AC components of different frequencies and smoothed and pulsating DC residual current.

A current sensor circuit (1) comprises, for example, a sensing coil (N1) configured to change its inductance with a DC current, a resonant capacitor (C1), a phase-adjusting circuit (10) receiving a feedback signal from the resonant capacitor and outputting a driver signal, a circuit (20) having several switching elements (Q1, Q2) forming a half-bridge or full-bridge circuit, wherein the circuit causes the several switching elements to perform a switching operation according to a pulse period of the driver signal, so that an AC signal is supplied to the sensing coil and the resonant capacitor, a signal converter circuit (40) converting the driver signal output by the phase-adjusting circuit into a sensing signal indicating a change in the DC current, and a sensing terminal (DCSIG) outputting the sensing signal externally.

A voltage detection device and a method are disclosed. The voltage detection device comprises a liquid crystal display (LCD) shutter. The LCD shutter is configured to selectively alternate between a polarized state in which the LCD shutter blocks the static electric field and a non-polarized state in which the static electric field passes through the LCD shutter. Further, the voltage detection device comprises a sensor plate positioned to receive the static electric field that alternatingly passes through the LCD shutter such that an alternating current (AC) is induced in the sensor plate by the static electric field that alternatingly passes through the LCD shutter. Further, the voltage detection device comprises a converter configured to convert the AC into a voltage signal for measuring DC voltage present within a source.

The present disclosure relates to a method and a device for controlling an inverter. The method according to an embodiment of the disclosure may obtain first digital data for the AC output current of an inverter, second digital data for the AC output voltage of the inverter, third digital data for the DC input current of the inverter, and fourth digital data for the DC input voltage of the inverter on the basis of a plurality of sensors included in the inverter. In addition, the method may compare input power and output power on the basis of the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the method may determine whether there is an error in the inverter on the basis of the result of the comparison.

A fluxgate current sensor is provided that reduces the influence of interference signals depending on the operating conditions of the current being measured. [Solution] A method comprising: receiving a fluxgate signal corresponding to a primary current, wherein the fluxgate signal includes at least two plateau periods, each plateau period defining a plurality of candidate calculation windows (402); applying the signal characteristic set to a classification model to generate an operating condition classification based on the signal characteristic set, wherein the operating condition classification is one of (i) an AC operating condition indicating an AC primary current, or (ii) a DC operating condition indicating a DC primary current (404); selecting a calculation window from a plurality of calculation windows based on the operating condition classification, wherein the plurality of calculation windows include a first calculation window and a second calculation window (406); and determining a current value using the selected calculation window (408).

A fluxgate current sensor. A fluxgate signal corresponding to a primary current may be received. The fluxgate signal may include at least two plateau periods. Each plateau period may define a plurality of candidate calculation windows. An operation condition classification may be generated based on a signal characteristics set by applying the signal characteristics set to a classification model. The operation condition may be one of an AC operation condition or DC operation condition. A calculation window may be selected based on the operation condition classification. The plurality of calculation windows may include a first calculation window and a second calculation window. A predicted current value may be generated for the primary current by applying sampled current values within the selected calculation window for each of the at least two plateau periods to a prediction model.

Fluxgate current transducer including a control circuit and a fluxgate measuring device comprising a fluxgate magnetic field detector, the fluxgate magnetic field detector comprising a saturable soft magnetic core surrounded by an excitation coil, the control circuit comprising an excitation coil drive circuit connected to the excitation coil and a controller connected to the excitation coil drive circuit configured to generate an alternating excitation current Ifx to alternatingly saturate the soft magnetic core. The controller is in the form of a FPGA (Field Programmable Gate Array) comprising at least one input comprising a 1 bit sigma delta analog-to-digital converter (ADC) connected to the excitation coil to receive a measurement signal output by the excitation coil.

Embodiments of the present disclosure provide techniques for an improved fluxgate current sensor. A fluxgate signal corresponding to the primary current may be received. The fluxgate signal may include at least two stationary periods. Each stationary period may define a plurality of candidate computational windows. An operating condition classification may be generated based on the signal feature set by applying the signal feature set to a classification model. The operating condition may be one of an AC operating condition or a DC operating condition. A computing window may be selected based on the operating condition classification. The plurality of computing windows may include a first computing window and a second computing window. A predicted current value of the primary current may be generated by applying a sampled current value within a selected calculation window for each of the at least two stationary periods to a prediction model.

Embodiments of the present disclosure provide techniques for improved fluxgate current sensor. A fluxgate signal (120) corresponding to a primary current may be received. The fluxgate signal may include at least two plateau periods (210A, 210B). Each plateau period may define a plurality of candidate calculation windows (330A). An operation condition classification may be generated based on a signal characteristics set by applying the signal characteristics set to a classification model. The operation condition may be one of an AC operation condition or DC operation condition. A calculation window may be selected based on the operation condition classification. The plurality of calculation windows may include a first calculation window and a second calculation window. A predicted current value may be generated for the primary current by applying sampled current values within the selected calculation window for each of the at least two plateau periods to a prediction model.

In some examples, a method of performing measurement of a device under test (DUT) coupled to a connector includes determining a first voltage signal representative of a current of the DUT, the current flowing through the connector. The method also includes determining a second voltage signal representative of a voltage of the DUT, as provided at the connector. The method also includes determining a calibration current according to the first voltage signal. The method also includes modifying measurement of the DUT according to the calibration current.

Disclosed is a test device. The test device according to an embodiment of the present invention is operated by a power supply unit provided to be portable, and tests a sensor device using an alternating current of a high frequency. Therefore, the portability and operation reliability of the test device are improved, and the convenience of use can be improved since a separate wire member or the like for the operation of the test device need not be provided.

Signal processing circuit (10) comprising a modulation unit (11) for generating a modulated signal, an amplification unit (12) for amplifying the modulated signal and thereby creating an amplified modulated signal and a demodulation unit (14) for demodulating the amplified modulated signal and thereby creating a demodulated signal. The signal processing circuit (10) further comprises a zero current detection unit (13) connected to an output of the amplification unit (12) upstream of the demodulation unit and configured to detect a zero crossing of a current based on the amplified modulated signal.

This electric current sensor comprises: first and second input terminals configured so that both ends of a sense resistor can be connected thereto; a square wave generation circuit that is connected to the first and second input terminals and configured so as to be capable of generating a square wave signal having an amplitude proportional to the voltage between the two ends of the sense resistor; and an electric current detection signal output circuit configured so as to be capable of using the square wave signal as a basis to output an electric current detection signal corresponding to the electric current flowing through the sense resistor.

An absence of voltage indicator has an isolation circuit, an FM modulator attached to the isolation circuit, a reference oscillator, and a mixer attached to the reference oscillator and the FM modulator, wherein the output of the mixer is the difference of the two signals. In one embodiment, the FM modulator includes a variable capacitor which varies in response to a voltage in parallel to a fixed capacitor and an inductor in parallel to the capacitors.

Apparatuses, devices, and systems for operating a voltage converter to reduce current spike are described. A controller can measure a feedback of a current of an alternating current (AC) voltage of a switching circuit. The controller can measure a direct current (DC) voltage of the switching circuit. The controller can operate a current control loop using the feedback of the current to determine a target voltage. The controller can determine a duty cycle of the switching circuit based on the target voltage and the DC voltage. The controller can operate the switching circuit under the determined duty cycle to control the current of the AC voltage.