36results 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.

Fluxgate current transducer (2) including a control circuit (4) and a fluxgate device (2) comprising a saturable soft magnetic core (6) surrounded by an excitation coil (8), the control circuit comprising an excitation coil drive circuit connected to the excitation coil configured to generate an alternating magnetic field to alternatingly saturate the soft magnetic core. The excitation coil comprises a first winding (8a) and a second winding (8b) connected together at a common point (9) forming an input of the first winding and an output of the second winding, the first winding connected in series to a first switch (S1) and the second winding connected in series to a second switch (S2). The first and second switches are controlled by the control circuit to provide an excitation coil current in the first winding generating a magnetic field in the magnetic core in a first direction, and an excitation coil current in the second winding generating a magnetic field in the magnetic core in a second direction opposite to the first direction.

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).

To estimate a current value of a power storage device with high precision.SOLUTION: An estimation system includes a battery 5, an inverter 20, a motor 25, a current sensor 30u, and an ECU 100. The inverter 20 includes an upper arm circuit 22u and a lower arm circuit 23u, an upper arm circuit 22v and a lower arm circuit 23v, and an upper arm circuit 22w and a lower arm circuit 23w. Modes of the inverter 20 include a first mode in which the upper arm circuit 22u, the lower arm circuit 23v, and the lower arm circuit 23w are on, and a second mode in which the lower arm circuit 23u, the upper arm circuit 23v, and the upper arm circuit 23w are on. The ECU 100 executes an estimation process of estimating a current value of the battery 5. The estimation process includes a first process of estimating the current value in accordance with a detection value obtained by the current sensor 30u when the inverter 20 is in the first mode or the second mode.SELECTED DRAWING: Figure 1

A differential sensing system for sensing a current through a circuit element of a circuit, the differential sensing system comprising: a first current sense path having an input for coupling to a first node of the circuit element, the first current sense path comprising a first plurality of replica devices; a second current sense path having an input for coupling to a second node of the circuit element, the second current sense path comprising a second plurality of replica devices, wherein the second plurality is equal to the first plurality; a first cross-coupling switch operable to couple the input of the first current sense path to the second plurality of replica devices; a second cross-coupling switch operable to couple the input of the second current sense path to the first plurality of replica devices; differential amplifier circuitry having first and second inputs, wherein the differential amplifier circuitry is configured to output a differential replica current pair indicative of the current through the circuit element; and a controller, wherein the differential sensing system is operable in a chopping mode to perform a chopping operation in which: the first cross-coupling switch and a replica device of the first current sense path are controlled by the controller to couple the first input of the differential amplifier circuitry to the input of the first current sense path in a first phase of a chopping operation and to the input of the second current sense path in a subsequent phase of the chopping operation; and the second cross-coupling switch and a replica device of the second current sense path are controlled by the controller to couple the second input of the differential amplifier circuitry to the input of the second current sense path in the first phase of the chopping operation and to the input of the first current sense path in the subsequent phase of the chopping operation.

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.

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.

The invention provides a zero cross detection circuit. The zero-cross detection circuit includes a variable resistor, a first switch, a first capacitor, a first selector, a second selector, a first transistor, and a comparator. The variable resistor is connected to a supply voltage through a reference resistor. The first switch has a first end coupled to a first end of the variable resistor. The first capacitor has a first end coupled to a second end of the first switch. The first selector enables the second end of the first capacitor to receive the switching voltage or the reference grounding voltage according to the first control signal. The first transistor has a first end coupled to a second end of the variable resistor, and a second end of the first transistor receives a reference ground voltage. The second selector enables the control end of the first transistor to be coupled to the first end of the first transistor or the first end of the first capacitor according to a first control signal. The comparator compares the voltage on the second end of the variable resistor with a reference voltage to generate a final zero-crossing detection output signal.

The present application provides a current detection circuit, comprising a current transformer, a magnetic reset circuit, a chip select circuit, a sampling circuit and a clamp circuit. The primary winding of the current transformer receives the current to be detected and generates a sampling current in the secondary winding. The magnetic reset circuit is used to reset the current transformer. The chip select circuit is electrically connected to the magnetic reset circuit and can be switched between a first mode and a second mode. The first mode is used to detect a current to be detected having a first direction, and the second mode is used to detect a current to be detected having a second direction opposite to the first direction. The sampling circuit is electrically connected to the chip select circuit to sample the sampling current and output a sampling signal to a controller. The clamp circuit is electrically connected between the sampling circuit and the controller and provides a reference potential. The present application also provides a converter having the current detection circuit.

An estimation system includes a battery (5), an inverter (20), a motor (25), a current sensor (30u), and an ECU (100). The inverter (20) includes an upper arm circuit (22u) and a lower arm circuit (23u), an upper arm circuit (22v) and a lower arm circuit (23v), and an upper arm circuit (22w) and a lower arm circuit (23w). A mode of the inverter (20) includes a first mode in which the upper arm circuit (22u), the lower arm circuit (23v), and the lower arm circuit (23w) are on and a second mode in which the lower arm circuit (23u), the upper arm circuit (22v), and the upper arm circuit (22w) are on. The ECU (100) performs estimation processing for estimating a current value of the battery (5). The estimation processing includes first processing for estimating the current value in accordance with a detection value from the current sensor (30u) when the mode of the inverter (20) is set to the first mode or the second mode.

A fluxgate current converter (2) comprises a control circuit (4) and a fluxgate device (2), the fluxgate device comprising a saturable soft magnetic core (6) surrounded by an excitation coil (8), the control circuit comprising an excitation coil drive circuit connected to the excitation coil, the excitation coil drive circuit being configured to generate an alternating magnetic field to alternately saturate the soft magnetic core. The excitation coil comprises a first winding (8a) and a second winding (8b) connected together at a common point (9), the common point forming an input of the first winding and an output of the second winding, the first winding being connected in series with the first switch (S1) and the second winding being connected in series with the second switch (S2). The first switch and the second switch are controlled by the control circuit to provide an excitation coil current in the first winding, thereby generating a magnetic field in a first direction in the magnetic core, and the excitation coil current in the second winding generating a magnetic field in a second direction opposite to the first direction in the magnetic core.

System and method for detecting one or more currents. For example, a system for detecting one or more currents includes: one or more current sampling units coupled to one or more terminal transistors respectively and configured to sample one or more terminal currents that flow between a system terminal of a power management system and one or more port terminals through the one or more terminal transistors respectively; one or more operational amplifiers coupled to the one or more current sampling units respectively and configured to generate one or more detection currents respectively, the one or more detection currents representing one or more magnitudes of the one or more terminal currents respectively; and a signal combiner configured to receive the one or more detection currents, generate a combined detection voltage representing a sum of the one or more magnitudes of the one or more terminal currents.

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.

A magnetic field gradient transducer (1) for surface mounting on a circuit board (21), comprising:-an integrated circuit (IC) chip (2) comprising an active first side (9a), a second side (9b), at least two magnetic field sensing portions (20) on the active side, and connection terminals (11) on the active side, the at least two magnetic field sensing portions (20) are separated by a gap (G) configured for magnetic field gradient measurement; a leadframe structure (3) comprising a plurality of secondary conductors (5) and a shielding conductor (6), the shielding conductor being in overlapping relationship with the IC chip; -a plurality of secondary conductor bonding wires (14) interconnecting two or more of the secondary conductors (5) to the connection terminals (11) of the IC chip; and-an insulating housing (7) overmolded on the IC chip, the secondary conductor bonding wires and a portion of the lead frame structure (3), whereby the circuit board contact portions of the secondary conductor and the shielding conductor are exposed and configured for surface-mounted connection with the external circuit board. The shielding conductor has a non-recessed portion (12) and a recessed portion (13) on which the IC chip is mounted, the thickness H2 of the recessed portion being smaller than the thickness H1 of the non-recessed portion and the secondary conductor.

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.

Fluxgate current transducer (2) including a control circuit (4) and a fluxgate device (2) comprising a saturable soft magnetic core (6) surrounded by an excitation coil (8), the control circuit comprising an excitation coil drive circuit connected to the excitation coil configured to generate an alternating magnetic field to alternatingly saturate the soft magnetic core. The excitation coil comprises a first winding (8a) and a second winding (8b) connected together at a common point (9) forming an input of the first winding and an output of the second winding, the first winding connected in series to a first switch (S1) and the second winding connected in series to a second switch (S2).

A current sensing apparatus may include a common mode core surrounding two or more current conductors and a current sensing element proximate the common mode core.

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.

Fluxgate current transducer (2) including a control circuit (4) and a fluxgate device (2) comprising a saturable soft magnetic core (6) surrounded by an excitation coil (8), the control circuit comprising an excitation coil drive circuit connected to the excitation coil configured to generate an alternating magnetic field to alternatingly saturate the soft magnetic core. The excitation coil comprises a first winding (8a) and a second winding (8b) connected together at a common point (9) forming an input of the first winding and an output of the second winding, the first winding connected in series to a first switch (S1) and the second winding connected in series to a second switch (S2).

Fluxgate current transducer (2) including a control circuit (4) and a fluxgate device (2) comprising a saturable soft magnetic core (6) surrounded by an excitation coil (8), the control circuit comprising an excitation coil drive circuit connected to the excitation coil configured to generate an alternating magnetic field to alternatingly saturate the soft magnetic core. The excitation coil comprises a first winding (8a) and a second winding (8b) connected together at a common point (9) forming an input of the first winding and an output of the second winding, the first winding connected in series to a first switch (S1) and the second winding connected in series to a second switch (S2).

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.