91 results about "Common-mode signal" patented technology

A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.

A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.

The invention relates to the technical field of wireless receivers, and discloses a low-noise amplifier and a radio frequency front-end circuit, the low-noise amplifier comprises a biasing circuit and an amplifying circuit, the low-noise amplifier converts an input single-ended radio frequency signal into differential output through an MOS tube NM2 and an MOS tube NM3, and large gain is provided; secondly, external impedance matching can be better realized through single-end input, and the anti-interference capability can be enhanced through differential output; the MOS tube NM0 and the MOS tube NM1 of the low-noise amplifier are connected in a cross coupling mode, differential current imbalance can be calibrated, and noise performance is improved. Finally, the structure of the low-noise amplifier enables the noise introduced by the MOS tube NM2 to become a common-mode signal, and the introduced noise is eliminated; the mixer circuit adopts a double-balanced active mixer, common-mode signals can be well suppressed by adopting differential pair input, a local oscillator input end and a radio frequency input end are well isolated, external interference is small, and the mixer adopts a folding structure, can work under low power supply voltage and effectively reduces power consumption.

The invention relates to the technical field of optical element surface physical property testing, and discloses an optical element surface pattern structured light testing system which comprises the steps that a pair of phase-conjugated structured light fields are adopted to alternately illuminate an optical element, and Fourier domain diffraction patterns and spatial domain in-situ light field intensity distribution of the optical element are synchronously collected; according to the method, a common-mode signal cancellation mechanism aiming at a defect-free periodic pattern is preset on a physical level through conjugate illumination and differential processing, so that massive redundant information is suppressed, and the defect position is determined by calculating a differential signal after a diffraction pattern is corrected by using in-situ light field intensity distribution. According to the method, only asymmetric scattering signals caused by defects are reserved and highlighted, so that the focus of detection is changed from measurement of the accuracy of geometrical morphology to discrimination of the uniformity of optical response physical properties of materials, and high-signal-to-noise-ratio rapid discrimination of functional defects is realized.

The embodiment of the invention provides a multi-lead wireless wearable myoelectricity acquisition system, and belongs to the crossing field of biomedical engineering and electronic technology. The electromyographic acquisition system comprises an electromyographic electrode pair module used for acquiring electromyographic signals and sending the electromyographic signals to an active circuit module; the active circuit module is used for processing the received electromyographic signals so as to improve the anti-interference capability and the acquisition accuracy, and sending the processed electromyographic acquisition input signals to the electromyographic acquisition module; due to the special design of the active circuit module, the active circuit module has the characteristics of ultrahigh input impedance, low voltage noise, bias current and the like, noise interference of electromagnetism, environment, motion and the like can be effectively resisted, meanwhile, power frequency interference is further reduced by processing common-mode signals through the auxiliary driving module, the stability and reliability of electromyographic signal acquisition in a complex environment are ensured, and the electromyographic signal acquisition efficiency is improved. And signals can be accurately acquired in sports venues or places with dense electronic equipment.

The utility model relates to the technical field of transducers, and discloses an ultrasonic echo detection circuit, comprising a common-mode module which is connected to a first echo input end and a second echo input end, receives a first input signal and a second input signal, and is used for carrying out common-mode processing on the first input signal and the second input signal and sending the processed signal to a processor; obtaining and outputting a first direct-current signal and a second direct-current signal; the amplification module is connected with the common-mode module, receives the first direct-current signal and the second direct-current signal, amplifies the first direct-current signal and the second direct-current signal respectively, and outputs the amplified first direct-current signal and the amplified second direct-current signal; and the filtering module is respectively connected with the amplification module and the echo output end, receives the amplified first direct current signal and the amplified second direct current signal, filters common-mode signals for the amplified first direct current signal and the amplified second direct current signal to obtain a differential signal, and outputs the differential signal to the echo output end. The problems that detected ultrasonic echo signals are large in signal noise and low in integrity are solved.

Reversed semilattice filters with improved common mode rejection characteristics are disclosed. In one aspect, a filter may include two interior nodes coupled with an impedance that treats unwanted signals as common mode signals and provides rejection for common mode signals while passing differential signals of interest. The impedance is modified to have a resonant circuit that improves signal rejection in the stop band by lowering the effective impedance at those frequencies while leaving the pass band unaffected.

The invention discloses a power supply electromagnetic compatibility filter which comprises a three-phase alternating current input end, a first-stage differential mode capacitor circuit, a first-stage differential mode inductor circuit, a common mode capacitor circuit, a second-stage differential mode capacitor circuit, a second-stage differential mode inductor circuit and a three-phase alternating current output end which are in communication connection in sequence. Wherein the first-stage differential mode capacitor circuit, the first-stage differential mode inductor circuit, the second-stage differential mode capacitor circuit and the second-stage differential mode inductor circuit form a differential mode signal suppression circuit, and the differential mode signal suppression circuit is used for suppressing differential mode interference signals in a three-phase alternating current circuit; the first-stage differential mode inductance circuit, the common mode capacitance circuit and the second-stage differential mode inductance circuit form a common mode signal suppression circuit, and the common mode signal suppression circuit is used for suppressing common mode interference signals in the three-phase alternating current circuit, so that the problems of substandard electromagnetic compatibility, relatively high cost and huge size in the existing filtering technology are solved.

The present application relates to a tester and a differential comparator calibration device thereof, the device comprising: a pin circuit module comprising a differential arithmetic unit, a first channel comprising a first drive digital-to-analog converter, a first comparison digital-to-analog converter unit and a first differential comparator unit, and a second channel comprising a second drive digital-to-analog converter, a second comparison digital-to-analog converter unit and a second differential comparator unit; the second channel includes a second driving digital-to-analog converter, a second comparison digital-to-analog converter unit, and a second differential comparator unit. The first driving digital-to-analog converter outputs a first driving signal to the differential arithmetic unit, and the second driving digital-to-analog converter outputs a second driving signal to the differential arithmetic unit. The differential mode output end of the differential arithmetic unit outputs a differential mode signal to the first differential comparator unit, and the common mode output end of the differential arithmetic unit outputs a common mode signal to the second differential comparator unit. And the calibration module is used for calibrating the first differential comparator unit / the second differential comparator unit according to the comparison result level output by the first differential comparator unit / the second differential comparator unit.

The application relates to an antenna assembly and an electronic device, wherein the antenna assembly comprises a main body part and a feeding assembly, the main body part is provided with a first slot antenna and a second slot antenna and an isolation structure, a first feeding part and a second feeding part are arranged in the first slot antenna and the second slot antenna respectively, the isolation structure can comprise a first isolation slot perpendicular to the slot antenna and / or a second isolation slot parallel to the slot antenna, the first isolation slot is used for adjusting a differential mode signal impedance, the second isolation slot is used for adjusting a common mode signal impedance, the overall isolation degree of the antenna assembly is improved by adjusting the differential mode signal impedance and / or the common mode signal impedance, so that the signal quality of the antenna is improved, the possibility of mutual interference between different signals is reduced, and the actual use requirement is met.

The invention discloses a bidirectional amplifier structure, a front-end system, a chip array element and a phased array system. The bidirectional amplifier structure comprises a differential mode signal amplification path; a common mode signal amplification path; the four-branch waveguide joint comprises a common-mode amplification interface, two differential-mode amplification interfaces and two antenna interfaces, the differential-mode amplification interfaces are in one-to-one correspondence with the antenna interfaces, the differential-mode amplification interfaces are connected with the differential-mode signal amplification path, and the common-mode amplification interface is connected with the common-mode signal amplification path; the amplification stage comprises a differential amplification circuit and a common mode amplification circuit; and the matching stage comprises a differential mode matching structure and a common mode matching structure, the differential mode matching structure is connected with the differential amplification circuit, and the common mode matching structure is connected with the common mode amplification circuit. According to the structure of the bidirectional amplifier, the working mode of simultaneous working or time-sharing working is realized by utilizing the characteristics of a signal differential mode and a common mode, and the bidirectional amplifier has higher working efficiency, higher circuit multiplexing rate and higher integration level. The invention relates to the technical field of microwave communication.

The utility model discloses a high-precision differential capacitive MEMS pressure sensor, which comprises a top plate layer, an upper bonding layer, a sensitive structure layer, a lower bonding layer and a bottom plate layer which are sequentially arranged from top to bottom, a top layer capacitance plate, a sensitive layer capacitance plate and a bottom layer capacitance plate are correspondingly arranged in the middle of the top plate layer, the middle of the sensitive structure layer and the middle of the bottom plate layer respectively, and a plurality of through top layer air holes are formed in the top layer capacitance plate; an upper capacitance gap communicated with the top-layer air hole is formed between the top-layer capacitance plate and the sensitive-layer capacitance plate, and a vacuum-sealed lower capacitance gap is formed between the sensitive-layer capacitance plate and the bottom-layer capacitance plate; the sensitive structure layer comprises a sensitive layer frame and a sensitive layer capacitance plate, the sensitive layer capacitance plate is arranged in the middle of the sensitive layer frame, and the peripheral side of the sensitive layer capacitance plate is connected with the sensitive layer frame through a sensitive layer elastic film. According to the utility model, the suppression of common-mode signals is enhanced, and the signal-to-noise ratio of output signals is improved; and meanwhile, the linearity between the capacitance value variation and the air pressure or pressure variation is improved, and good practicability is achieved.

The present disclosure relates to non-contact voltage measurement. It includes a non-contacting voltage measuring apparatus for measuring a first voltage of a conductor. The apparatus comprises: a probe for capacitively coupling with the conductor; a first measurement capacitor having a first node and a second node, wherein the first node of the measurement capacitor is coupled to the probe to form a capacitive potential divider; a reference signal generator coupled to the second node of the measurement capacitor for applying a signal at a different frequency to the first voltage; and a measurement circuit coupled to the first node and the second node of the measurement capacitor, the measurement circuit configured to measure a second voltage across the measurement capacitor and determine the first voltage.

A differential channel circuit structure is disclosed. The differential channel circuit structure comprises a first differential circuit including a differential channel and a termination circuit. The differential channel has a differential mode impedance and a common mode impedance, and includes a first end and a second end, each capable of processing at least a first differential signal and a first common mode signal. The termination circuit includes a third end and a fourth end connected to the first end and the second end of the differential channel respectively, so as to simultaneously match the differential mode impedance and the common mode impedance of the differential channel.

A method, a control circuit, and a power converter arrangement are disclosed. The method includes: coupling three power converters (1, 2, 3) with each other; connecting each of the three power converters (1, 2, 3) to a 3-phase power source (4) configured to provide three supply voltages (Ua, Ub, Uc); and regulating a respective input signal (V1, V2, V3; I1, I2, I3) of each of the three power converters (1, 2, 3) dependent on a common mode signal (Scm).

The invention provides an arc fault breaker, an energy storage unit, an energy storage device and an energy storage system, relates to the technical field of energy, and is used for improving the sampling capability of the arc fault breaker and further improving the accuracy of arc fault detection. The arc fault breaker comprises a first current sensor, a second current sensor, a first signal detection circuit, a second signal detection circuit and a controller. The first current sensor and the second current sensor are used for outputting a first sampling signal and a second sampling signal respectively according to a current signal transmitted between the battery module and the converter; the first signal detection circuit is used for outputting a differential mode signal according to the first sampling signal and the second sampling signal; the second signal detection circuit is used for outputting a common-mode signal according to the first sampling signal and the second sampling signal; and the controller is used for disconnecting the battery module and the converter under the condition that the spectrum characteristic of the differential mode signal and the spectrum characteristic of the common mode signal are matched with the spectrum characteristic of the arc fault signal.

A plug connector (200) includes a plug housing (210) having a power contact channel (212) and first and second module channels (214). The plug connector includes power contacts received in the power contact channels and a data module (400) received in the first module channel. The data module includes a data module housing (410) that holds signal contacts (402) terminated to an end of a signal line (404) of a data cable (206). The plug connector includes a common mode end node terminal module (500) received in the second module channel, the end node terminal module having a common mode signal processing assembly with an end node PCB (552) having a common mode control circuit and signal processing components for processing signals on the common mode control circuit. The plug connector includes a jumper contact (600) and a ground jumper contact (700) electrically connected to the common mode end node terminal module.

The utility model discloses a filter circuit for solving interference of anion products on other equipment, and belongs to the technical field of anions. The filter circuit provided by the utility model comprises the common-mode signal filter and the differential-mode signal filter, the filter circuit is connected between the negative ion equipment and the power supply, and common-mode interference and differential-mode interference generated by a negative ion product in the use process are respectively filtered by the common-mode signal filter and the differential-mode signal filter in the filter circuit. The influence of interference signals on other electric appliances connected to the same power supply through the power supply is avoided, the damage to equipment is reduced, and the use safety of the negative ion electric appliance is improved.

A system, comprising: a reference magnetic field source that is configured to generate a reference magnetic field; a plurality of magnetic field sensing elements arranged in a sensing bridge, the sensing bridge being configured to sense the reference magnetic field and an external magnetic field simultaneously, the sensing bridge being configured to output a first signal and a second signal; a first circuit that is configured to generate a common mode signal of the sensing bridge based on the first signal and the second signal; an adjustment circuit that is configured to adjust a sensitivity of the sensing bridge based, at least in part, on a common mode signal of the sensing bridge; and a processing circuitry that is configured to use a differential signal of the sensing bridge to generate an output signal, the differential signal being based on a strength of the external magnetic field.

To suppress the effect of common-mode noise signals superimposed on differential communication signals on communication.SOLUTION: A transmitting / receiving circuit 11 includes an attenuator 26 that attenuates a differential communication signal input via an insulation circuit 8 and supplies the attenuated signal to a receiving circuit 25, and a common mode signal suppression circuit 28 that suppresses a common mode noise signal superimposed on the differential communication signal based on an output signal of the attenuator 26. The common mode signal suppression circuit 28 includes a common mode signal detection circuit that detects a common mode voltage in the output signal of the attenuator 26, a first current generation circuit that generates a first correction current proportional to a first different voltage when the first different voltage obtained by subtracting a first reference voltage from the detected common mode voltage is a negative voltage, and supplies the first correction current to an input / output terminal of the transmitting / receiving circuit 11, and a second current generation circuit that generates a second correction current proportional to a second different voltage when the second different voltage obtained by subtracting the detected common mode voltage from a second reference voltage is a positive voltage, and supplies the second correction current to the input / output terminal of the transmitting / receiving circuit 11.SELECTED DRAWING: Figure 3

A power converter is provided. In one aspect, the power converter has a first inverter and a second inverter electrically coupled with one another and with a power bus. First switches of the first inverter are arranged symmetrically with second switches of the second inverter so that, when switched in a pulse width modulated switching scheme, the first switches generate a first common mode signal and the second switches generate a second common mode signal that is one hundred eighty degrees out of phase with the first common mode signal. In another aspect, the power converter includes a buck stage having one or more pairs of symmetrically arranged buck switches that can be controlled to reduce or eliminate common mode electromagnetic interference in the buck stage. The power converter can also include one or more pairs of symmetrically arranged inductors.

The present disclosure relates to a diplexer with an impedance inverter. The diplexer can be used to isolate a transmitter and a receiver that share a common antenna. The diplexer is balanced by using an impedance gradient that provides an impedance that causes a balun of the diplexer to cut off access to the common antenna rather than replicate the antenna impedance. Such a cut off can have lower insertion loss than a diplexer that replicates the antenna impedance only to separate differential signals and common mode signals of the receiver and transmitter.

A voltage sensing circuit for measuring a load connected to a power amplifier, the load for receiving opposite phase first and second voltages, the voltage sensing circuit comprising a first input coupled to the first voltage, a second input coupled to the second voltage, a first voltage divider circuit, a second voltage divider circuit, and a second voltage divider circuit. The circuit includes a first voltage divider circuit including an input coupled to the first input terminal and an output coupled to the first output terminal, a second voltage divider circuit including an input coupled to the second input terminal and an output coupled to the second output terminal, and a driver circuit including a first input for receiving a reference voltage, a second input to receive a common mode signal of the first and second voltage divider circuits, and an output to drive an output common mode voltage of the first and second voltage divider circuits with the reference voltage.

A plug connector includes a plug housing having a power contact channel and first and second module channels. The plug connector includes a power contact received in the power contact channel and a data module received in the first module channel. The data module includes a data module housing holding signal contacts terminated to ends of signal wires of a data cable. The plug connector includes a common mode end node termination module received in the second module channel having a common mode signal processing assembly with an end node PCB with a common mode control circuit and signal processing component for processing signals on the common mode control circuit. The plug connector includes jumper contacts and a ground jumper contact electrically connected to the common mode end node termination module.

A signal detection circuit (400) includes a signal input terminal (402), a rectifier circuit (404), a comparator circuit (406); a current source (408), and a comparator output terminal (412). The rectifier circuit (404) is coupled to the signal input terminal (402) and configured to receive an input signal and generate a rectified signal based on the input signal. The comparator circuit (406) is coupled to the rectifier circuit (404) and configured to receive a common mode signal and generate a difference current based on a difference of the common mode signal and the rectified signal. The current source (408) is coupled to the comparator circuit (406) and configured to generate a reference current. The comparator output terminal (412) is configured to provide an output signal based on a difference of the reference current and the difference current.

A wireless power transfer transmitter can include a transmitter coil configured to deliver power to an inductively coupled receiver coil in a wireless power transfer receiver, a power converter configured to drive the transmitter coil, and means for driving the transmitter coil with a common-mode coupled communication signal to the wireless power transfer receiver. The means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a common mode signal driver configured to receive a data input signal and generate therefrom a signal to be injected into the transmitter coil. Alternatively, the means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a controller configured to drive the inverter with alternating complementary duty cycles.

The application discloses a new general method for eliminating electric and magnetic interference in measurement system. For electric measurement using differential amplifier, common mode signal is led out from differential amplifier and amplified as interference signal. After the amplified signal is sampled, it is used as interference template. The matching template component is searched in signal and then subtracted from the signal to eliminate interference and improve signal to noise ratio. For magnetic signal detection sensor using gradient coil structure, the center is grounded and two signal ends output mixed signal containing common mode component representing interference and measured signal. The common mode component is led out from differential amplifier as interference template to complete elimination of interference component in signal through the same template matching analysis and subtraction. The method for eliminating electromagnetic interference can be widely used in electric and magnetic signal measurement system.

The invention relates to the technical field of measuring instrument detection, and discloses an empty pipe detection method and system of an electromagnetic flowmeter and the electromagnetic flowmeter. The method comprises the steps that an excitation signal is applied to a signal electrode within a preset time period; wherein the preset time period is the front section of each half excitation period of the excitation signal; acquiring a to-be-sampled signal in a preset time period, and calculating an empty pipe detection voltage between a signal electrode and a grounding electrode according to the to-be-sampled signal; calculating the conductivity of the medium in the pipe according to the first preset value, the second preset value and the empty pipe detection voltage; according to the conductivity, whether the electromagnetic flowmeter is in a blank pipe state or not is detected. According to the embodiment of the invention, the influence of a common-mode signal on blank pipe detection can be reduced, and the blank pipe detection accuracy of the electromagnetic flowmeter is further improved.

An isolation circuit for isolating a transmitting end and a receiving end is provided. The isolation circuit comprises: a clock end configured to receive a clock signal; a common mode signal end configured to receive a common mode signal; a transmitting end circuit configured to: perform signal processing on a plurality of data signals, the clock signal, and the common mode signal; and output a first signal comprising the plurality of data signals, the clock signal, and the common mode signal after signal processing; an isolation capacitor circuit configured to isolate a direct current component in the first signal to output a second signal; and a receiving end circuit configured to: demodulate the second signal to obtain a third signal corresponding to the plurality of data signals and a fourth signal corresponding to the clock signal; and demodulate and demultiplex the third signal based on the fourth signal.

The present application discloses a crystal oscillator circuit, an integrated circuit and an electronic device, including an oscillation module for generating a first oscillation signal and a second oscillation signal and outputting them to a rectifier module; a reference oscillation module for generating a reference common-mode signal and outputting them to a rectifier module; a rectifier module for generating a reference voltage signal and a rectifier signal according to the reference common-mode signal and the oscillation signal, respectively, and outputting them to a regulating module; a regulating module for generating a regulating voltage signal according to the reference voltage signal and the rectifier signal to control a regulating current and outputting the regulating current to the oscillation module to control the amplitude of the first oscillation signal and the second oscillation signal; and also including a bias module for providing working conditions for the oscillation module and the reference oscillation module. The power consumption of the crystal oscillation circuit during the oscillation process is reduced, the circuit area is reduced, and the oscillation amplitude of the crystal oscillation circuit is precisely controlled when the wide voltage and integrated circuit process change.