44 results about "Differential mode noise" patented technology

An active compensation device including a first element group including an integrated sensing / compensation unit configured to generate a sensing signal corresponding to at least one of common-mode noise and differential-mode noise on at least two high-current paths, and a second element group including a compensation control unit including a negative impedance converter and configured to generate a compensation signal corresponding to the sensing signal and provide the compensation signal to the integrated sensing / compensation unit. The compensation control unit further including a stabilization unit configured to prevent oscillation caused by the sensed noise. The first element group and the second element group are mounted on a single substrate.

Disclosed in the present invention is a filter circuit. A first PCB layer consists of a power line, a power interface, a second filter capacitor, and a first filter capacitor; the power line comprises a power supply network and a GND network; the second PCB layer is provided with a conductor plane; the power interface is connected to the GND network and is further connected to the conductor plane; the GND network, the second filter capacitor, and the conductor plane are sequentially connected; the power supply network, the first filter capacitor, and the conductor plane are sequentially connected. The circuit design of the circuit structure and the overall layout design idea in the present invention have a good suppression effect on common-mode noise, differential mode noise, radiation noise and conduction noise.

This utility model discloses a frequency converter controller, including a control unit, a first filtering topology, and a second filtering topology. The first filtering topology includes a differential-mode inductor unit, and the second filtering topology includes a common-mode inductor unit. The first filtering topology is connected to the live wire, neutral wire, and protective ground wire, and receives the input signal from the power input terminal, suppresses the differential-mode noise and common-mode noise of the input signal from the power input terminal, and generates a first electrical signal. The second filtering topology receives the first electrical signal, suppresses the differential-mode noise and common-mode noise of the first electrical signal, and generates a second electrical signal. The control unit receives the second electrical signal. Because a differential-mode inductor unit is added to the first filtering topology, the number of magnetic rings can be reduced, the number of installation steps can be reduced, and costs can be optimized.

To provide a technique capable of suppressing differential mode noise in addition to common mode noise in a noise filter connected to a pair of power lines.SOLUTION: A noise filter disclosed in the present specification is a noise filter connected to a pair of power lines, and includes a first bypass capacitor connected between one of the pair of power lines and a ground, a second bypass capacitor connected between the other of the pair of power lines and the ground, a first resistive element connected in series with the first bypass capacitor, and a second resistive element connected in series with the second bypass capacitor.SELECTED DRAWING: Figure 2

The utility model discloses an active choking coil, which comprises at least three groups of coils, two groups of coils are used for power current of a power line to flow through, and the other group of coils are used for active suppression current to flow through; the active suppression current generating circuit is coupled with the coils and generates the suppression current; the capacitor is connected in parallel with the two groups of coils through which power current flows, so as to serve as a filter of the power line; according to the utility model, the common-mode and differential-mode noise suppression effect or the EMI suppression effect is enhanced mainly through the active current generator circuit, so that the cost and the size of the isolator or the EMI suppression circuit are reduced. Because the length of the copper wire is reduced, the energy consumption of the isolator or the EMI suppression circuit is lower than that of the traditional method, and the energy loss is reduced.

The application provides a level shift circuit based on current compensation, a low-voltage pulse signal is connected to a first level input end and a second level output end respectively, so that the two low-voltage pulse signals are converted into two high-voltage pulse signals, and the high-voltage pulse signals are output to a current compensation circuit and a common mode noise elimination circuit through a first level output end and a second level output end; the output of the current compensation circuit and the common mode noise elimination circuit jointly influences the signal state of R end and S end in a latch, and the latch is used for restoring the high-voltage pulse signal into a floating square wave signal with the same phase as the input signal. The application not only can resist high common mode noise, but also has a good inhibitory effect on differential mode noise, and effectively improves the stability and reliability of the level shift circuit.

The utility model belongs to the technical field of electronic components, and particularly relates to a common-mode inductor integrated with differential-mode filtering, which comprises a bottom plate and a common-mode magnetic core, a partition plate is fixedly connected to the top of the bottom plate, a placement groove is formed in the partition plate, a magnetic conductive sheet is arranged in the placement groove, and the common-mode magnetic core is arranged in the placement groove. According to the common-mode inductor, the common-mode magnetic core is matched with the two winding coils, common-mode noise is effectively restrained, the containing groove is formed in the partition plate in the middle of the common-mode inductor, and the magnetic conductive sheet is arranged in the containing groove, so that the common-mode inductor is integrated with a differential-mode inductor and has the capability of filtering differential-mode noise, and the common-mode inductor has the advantages of being simple in structure and convenient to use. An additional differential mode inductor is avoided, and cost reduction and space saving are realized.

The application discloses a wideband active EMI filter circuit and a control method thereof, which comprises a high-frequency common-mode inductance module, an amplification filter module and a differential-mode filter module, the high-frequency common-mode inductance module further comprises two sampling signal output ports, and the sampling common-mode noise is connected to two input ports of the amplification filter module respectively after sampling; the output port of the amplification filter module is connected to the differential-mode filter module, and the differential-mode noise is filtered in the differential-mode filter module after the loop noise current is eliminated. Through the wideband active EMI filter circuit and the control method thereof, the compensation current signal is obtained through a novel sampling mode, the novel sampling mode is adopted, the purpose of wideband filtering is achieved, the stability of the filter is improved, meanwhile, the filter is small in size, wide in frequency band, high in stability, applicable to various space-limited scenes such as aerospace and industrial application, and the hardware design can make the matched product meet the electromagnetic compatibility requirement.

An active compensation device is provided. An active compensation device includes an integrated sensing / compensation unit configured to generate a sensing signal corresponding to at least one of common-mode noise and differential-mode noise on at least two high-current paths, and a compensation control unit including a negative impedance converter and configured to generate a compensation signal corresponding to the sensing signal and provide the compensation signal to the integrated sensing / compensation unit. The compensation control unit further includes a stabilization unit configured to prevent oscillation caused by the sensed noise.

This application provides an AC switching power supply. In this AC switching power supply, the input terminal of each inverter bridge arm is connected to the output terminal of a DC switching power supply; each output terminal of the AC switching power supply is connected to the output terminal of the corresponding inverter bridge arm. In this application, since the common-mode noise of at least two DC switching power supplies cancels each other out, the common-mode noise of the AC switching power supply is suppressed. Furthermore, since in the prior art, the drive signal frequencies of each DC switching power supply in the AC switching power supply are the same, i.e., the number of noise sources at the same frequency point is equal to the number of DC switching power supplies, when the number of DC switching power supplies is the same, the noise sources of this AC switching power supply at the same frequency point will not exceed those in the prior art. Therefore, the differential-mode noise of this AC switching power supply can at least remain unchanged. In summary, the AC switching power supply provided in this application suppresses its own EMI.

Motor-driven compressor (11) with: a compression section (18) which compresses fluid, an electric motor (19) which drives the compression section (18), an inverter device (30) which drives the electric motor (19), and a metal housing (14) accommodating the inverter device (30), wherein the inverter device (30) an inverter circuit (31) which converts direct current power into alternating current power, and a noise reduction device (32) arranged on an input side of the inverter circuit (31), the noise reduction device (32) reducing common-mode noise and differential-mode noise contained in the DC power before supply to the inverter circuit, the interference reduction device (32) a common mode choke coil (34), and a smoothing capacitor (35) which forms a low-pass filter circuit (36) together with the common-mode choke coil (34), the common mode choke coil (34) a loop-shaped core (50), a first winding (60) wound around the core (50), a second winding (61) wound around the core (50), the second winding (61) being located away from the first winding (60) and opposite the first winding (60), and a loop-shaped conductor (70) covering the core (50) while extending over the first winding (60) and the second winding (61), where the conductor (70) has sections which are opposite to each other and are located away from each other, with the first winding (60) and the second winding (61) therebetween, the conductor (70) has a heat radiation section (71) which is thermally coupled to the housing (14), and an average value of the electrical resistance value per unit length in a circumferential direction of the heat radiation portion (71) of the conductor (70) is greater than an average value of the electrical resistance value per unit length of locations other than the heat radiation portion (71).

The invention discloses an improved XY capacitor plate, and belongs to the field of electronic circuits, the improved XY capacitor plate comprises an X capacitor connected in parallel between a live wire and a zero line, and a first Y capacitor and a second Y capacitor respectively connected between the live wire and a ground wire and between the zero line and the ground wire, and the first Y capacitor and the second Y capacitor adopt symmetrical design and jointly form a pi-type filtering structure; compared with the prior art, differential mode and common mode noise can be efficiently suppressed, the harsh EMC requirement of a ship is met, the safety and reliability of the circuit are greatly improved through the application of the safety capacitor and the redundancy design of the Y capacitor, the electric shock risk caused by element failure is avoided, and part of the filtering function can still be reserved when a single point of fault occurs.

The invention discloses equipment for quickly positioning differential and common mode interference of electronic equipment for a CE102 test item, and belongs to the technical field of electromagnetic compatibility test. Comprising a metal shell, a differential-mode noise suppression module and a common-mode noise suppression module are arranged in the metal shell, four banana sockets and four control switches are arranged on a panel of the metal shell, the banana sockets are used for being connected with a test loop, and the control switches comprise two common-mode control switches and two differential-mode control switches. The two common-mode control switches are respectively connected with the input end and the output end of the common-mode noise suppression module, the two differential-mode control switches are respectively connected with the input end and the output end of the differential-mode noise suppression module, and the control switches are used for selectively connecting the differential-mode noise suppression module or the common-mode noise suppression module into a test loop. According to the invention, the interference type can be rapidly judged, multiple instrument functions are integrated, visual operation is realized through switch switching and light indication, the test efficiency and the positioning accuracy are improved, and on-site rapid troubleshooting is facilitated.

The invention relates to the technical field of signal processing, and discloses a touch integrated display module signal processing method and system. The method comprises the following steps: performing signal acquisition on a display driving circuit of a touch display module during a display frame interval to obtain mixed signal data; performing common-mode noise separation on the mixed signal data according to a common-mode noise reference to obtain touch signal data; identifying a differential mode noise component generated by a pixel driving voltage according to the touch signal data to obtain a differential mode noise separation result and a multi-point touch signal; extracting mixed coordinate data containing real touch points and phantom points according to the multi-point touch signal; based on the differential mode noise separation result, space geometric constraint verification and signal intensity inspection are conducted on the phantom points in the mixed coordinate data, and a touch positioning result is obtained.The phantom point recognition accuracy is ensured, the misjudgment rate is effectively reduced, and the touch reliability of the display module is improved.

The invention relates to a filter, an inverter and a vehicle, the filter comprises a connecting busbar, a magnetic ring and a capacitor, the connecting busbar is used for being electrically connected with an external electronic element, the magnetic ring sleeves part of the connecting busbar, the capacitor can be electrically connected with the connecting busbar, the capacitor comprises a first capacitor and a second capacitor, and the first capacitor and the second capacitor are electrically connected. The first capacitor can be matched with the magnetic ring to form a first differential-mode filter circuit, the second capacitor can be matched with the magnetic ring to form a second differential-mode filter circuit, and the frequency of differential-mode noise suppressed by the first differential-mode filter circuit is different from that of differential-mode noise suppressed by the second differential-mode filter circuit. According to the filter, the first capacitor and the second capacitor are arranged, the frequencies of suppressed noise are different, and a multi-stage and broadband noise absorption network is formed, so that the noise of different frequencies can be suppressed, the frequency of suppressing the noise can be widened, and applicable scenes can be increased.

The invention relates to a filter, an inverter and a vehicle, the filter comprises a connecting busbar, a first magnetic ring, a second magnetic ring and a capacitor, the connecting busbar is used for being electrically conducted with an external electronic element, the first magnetic ring sleeves a part of the connecting busbar, the second magnetic ring sleeves a part of the connecting busbar, and the capacitor is electrically connected with the first magnetic ring and the second magnetic ring. The capacitor can be electrically conducted with the connecting busbar, the first magnetic ring is a common-mode magnetic ring, the first magnetic ring can be matched with the capacitor to form a common-mode filter circuit, the second magnetic ring is a differential-mode magnetic ring, and the second magnetic ring can be matched with the capacitor to form a differential-mode filter circuit. According to the filter, common-mode noise and differential-mode noise are jointly suppressed, the filter can be applied to a high-voltage direct-current system, the first magnetic ring and the second magnetic ring are independent of each other and are designed in a split mode, and measurement of differential-mode inductance and impedance and measurement of common-mode inductance and impedance can be decoupled.

The utility model discloses a common-mode and differential-mode integrated inductor, which comprises a base provided with a separation positioning plate, two positioning grooves and four conductive pins; the magnetic core assembly comprises a closed-loop outer magnetic core and two open-loop inner magnetic cores, the two inner magnetic cores are located on the two opposite sides of the separation positioning plate respectively, the outer magnetic core comprises two outer longitudinal magnetic rods and two outer transverse magnetic rods, each inner magnetic core comprises an inner longitudinal magnetic rod, a center magnetic rod and two inner transverse magnetic rods, a magnetic gap notch is formed in the center of the center magnetic rod, and the two inner transverse magnetic rods are arranged in the center of the center magnetic rod. The central magnetic rod is propped against one side of the separation positioning plate; the two groups of coils are respectively arranged on the two positioning grooves, and each group of coils is wound outside the outer longitudinal magnetic rod and the inner longitudinal magnetic rod. The filter has the function of filtering common-mode noise and differential-mode noise at the same time, can effectively save space, can be widely applied to the field of electromagnetic interference filtering, can reduce loss when magnetic fields repel each other, and is high in consistency of hindering and suppressing the differential-mode noise when being used as two differential-mode inductors.

The utility model discloses a kind of multi-stage filtering integrated module of composite structure, electric drive system and vehicle, belong to new energy electric car electric drive technical field, multi-stage filtering integrated module of composite structure includes upper cover fastener, lower fastener, capacitor filter module, magnetic filter module, bus copper bar, external copper bar, connecting copper column;The magnetic ring is sleeved in the outer circumferential surface of copper bar along copper bar extension direction;Capacitor filter module includes PCB board and the capacitor welded on PCB board, capacitor filter module is crimped with bus copper bar by connecting copper column, another grounding hole is additionally provided on PCB board, ensure that the Y capacitor of connecting bus copper bar and ground can have good electrical contact with metal shell;The multi-stage filtering integrated module of composite structure can guarantee its effective suppression new energy electric car's common mode and differential mode noise in electric drive, while guarantee the simplicity of assembly and the stability of fastening, filtering integrated module meets national standard, with the characteristics of better electrical and structural stability.

The invention discloses a signal acquisition circuit and a signal acquisition method of an accelerometer, and belongs to the technical field of circuits. The accelerometer generates three-axis acceleration current signals; the signal conditioning module is used for converting the acceleration current signals of the three axes into voltage signals, and conditioning each path of voltage signals by using an operational amplifier and a rail-to-rail amplifier to obtain conditioning signals of the three axes; the signal acquisition module carries out triple redundancy sampling on the conditioning signals of the X axis and the Y axis and carries out double redundancy sampling on the conditioning signals of the Z axis; the controller calculates the dynamic weight of each path of sampling signal of the X axis and the Y axis and calculates optimization signals of the X axis and the Y axis according to each path of sampling signal and the dynamic weight, and the dynamic weight corresponding to each path of sampling signal is related to errors of sampling channels of the other two paths of sampling signals; and calculating an optimized signal of the Z axis for the two paths of sampling signals of the Z axis. According to the invention, the interference of common-mode noise and differential-mode noise can be reduced, and the precision influence caused by zero drift and performance difference between channels can be reduced.

The invention provides a high-frequency analog sensing signal remote fidelity transmitting method, which relates to the technical field of sensing signal processing, and comprises the following steps: preprocessing an original sensing signal based on a transmitting end to obtain a differential signal, carrying out carrier frequency modulation on the differential signal to obtain an output signal, and transmitting the output signal to a receiving end, and the receiving end demodulates and digitally processes the received signal to obtain a digital sensing signal. On the basis of differential frequency modulation of sensing signals, remote high-fidelity transmission of high-frequency analog signals of a complex noise interference field is achieved in combination with depth filtering, the physical anti-interference characteristic of differential frequency modulation is fully utilized on the premise that expensive digital transformation of a sensor end is not needed, and the high-fidelity transmission of the high-frequency analog signals of the complex noise interference field is achieved. And complex common-mode and differential-mode noise is intelligently separated and eliminated through a deep learning filter at a receiving end, so that the system cost and the complexity of a sending end are remarkably reduced, and the signal fidelity and the transmission reliability far superior to those of a traditional method are realized.

The invention relates to an integrated common-mode inductor and a switching power converter with the same. The integrated common-mode inductor comprises an iron core, a first winding, a second winding and a third winding, the iron core comprises a central magnetizer, a first side column magnetizer and a second side column magnetizer. The first winding is wound on the second side column magnetizer and wound on the first side column magnetizer. And the second winding is wound on the second side column magnetizer. And the third winding is wound on the second side column magnetizer. A first winding wound on the first side column magnetizer provides differential mode magnetic flux. And a first winding, a second winding and a third winding which are wound on the second side column magnetizer provide common-mode magnetic flux. On the premise that an independent magnetic element is not newly added, the shared iron core magnetic circuit can be used as an integrated inductor, miniaturization of the element is facilitated, and the EMI interference emission intensity of common-mode and differential-mode noise currents is reduced.

The utility model discloses an EMI (Electro-Magnetic Interference) suppression circuit, comprising a low-frequency common-mode suppression module which is used for suppressing power-frequency harmonic waves and low-frequency conduction noise and is composed of a three-phase ferrite core common-mode inductor L1; the differential mode discharge module is used for discharging differential mode noise and is composed of an X capacitor C1, an X capacitor C2 and an X capacitor C3; the high-frequency common-mode suppression module is used for suppressing high-frequency switching noise and diode reverse recovery ringing and is composed of a three-phase common-mode inductor L2; the common-mode grounding module is used for guiding common-mode noise to be discharged through a ground wire and is composed of a Y capacitor C4, a Y capacitor C5 and a Y capacitor C6, one end of each Y capacitor is connected with the three-phase line, and the other end of each Y capacitor is in common ground. According to the EMI suppression circuit, through collaborative design of the two stages of common-mode inductors, the differential-mode discharge module and the common-mode grounding module, the differential-mode inductor is omitted, the common-mode noise suppression capability is ensured, the circuit size is reduced, and the cost is saved.

A magnetic-resonance-imaging-compatible (MRI-compatible) cardiac defibrillator includes: a defibrillator generator; first and second electric wires, each being electrically connected to said defibrillator generator; first and second defibrillation pads, each being electrically connected to a respective one of said first and second electric wires; and a low pass filter electrically connected between said defibrillator generator and said first and second electric wires to prevent a noise in an MRI image caused by a radiofrequency interference from the defibrillator as well as protect a patient and the defibrillator from MRI radiofrequency imaging signals, wherein said low pass filter has a cutoff frequency set such that differential mode noise at an MRI Larmor frequency is in an attenuated band while a system-test signal by said defibrillator generator is in a pass band of said low pass filter.

An electric compressor (10) comprises a compression part (13), a motor (14), and an inverter device (15). The inverter device (15) has an inverter circuit unit (43) and a noise reduction unit (50) that reduces common-mode noise and differential-mode noise. The noise reduction unit (50) has a common-mode choke coil (51) that has a core (60), a first winding wire (61), and a second winding wire (62) and reduces common-mode noise, a smoothing capacitor (52), and a magnetic material damping section (55) in which an eddy current is induced by a leakage magnetic flux leaking from the core (60). The magnetic material damping section (55) reduces differential-mode noise. The noise reduction unit (50) has a plurality of the magnetic material damping sections (55).The plurality of magnetic material damping sections (55) are stacked with an insulation layer (73) disposed therebetween.

The utility model discloses a common mode inductor utilizing leakage inductance, which belongs to the technical field of inductors and comprises a mounting plate, a fixing block is fixedly connected to the top of the mounting plate, a common mode inductor assembly is fixedly connected to the top of the fixing block, and the common mode inductor assembly comprises a first magnetic core fixed to the top of the fixing block. A first coil and a second coil are wound on the outer side wall of the first magnetic core, and the outer side wall of the second coil is sleeved with a differential mode inductor assembly. According to the common-mode inductor utilizing leakage inductance, the common-mode inductor assembly, the first magnetic core, the first coil, the second coil and the differential-mode inductor assembly form a dual-mode inductor, the differential-mode inductor assembly is wound through the second coil, and when the second coil is wound on the outer side wall of the first magnetic core, the differential-mode inductor assembly is arranged on the outer side wall of the second coil in a sleeving mode; therefore, integration of the common-mode inductor and the differential-mode inductor is achieved in the same inductor, common-mode noise and differential-mode noise can be restrained at the same time, and the restraining effect on differential-mode interference is enhanced through leakage inductance.

The invention relates to an electrical circuit (6) comprising: two input terminals (13) connectable to a DC voltage; a control unit (7p, 7s); a first switching arm (B1, B3) comprising two controllable electronic switches (12) connected in series on either side of a first midpoint, the switches of the first arm being controlled by the control unit according to a first duty cycle; a second switching arm (B2, B4) comprising two controllable electronic switches (12) connected in series on either side of a second midpoint, the switches of the second arm being controlled by the control unit according to a second duty cycle; inductance units (10, 20) for contactless energy exchange consisting of inductors, mounted between first and second midpoints (14, 15), the first arms (B1, B3) and the second arms (B2, B4) being mounted in parallel, the circuit comprising a filter unit (11, 21) for filtering common and / or differential mode noise.

Disclosed is an active EMI filter for actively compensating for noise generated in a common mode and a differential mode in each of at least two high current paths, wherein the active EMI filter includes: a sensing unit for sensing the noise in the common mode and the differential mode on the high current paths; and a compensation unit that includes a negative impedance transformer, generates a compensation signal corresponding to the sensed noise, and provides the compensation signal to the sensing unit.

This invention relates to an MLVDS receiver circuit based on BiCMOS technology, comprising a common-mode converter circuit, a pre-amplifier circuit, type 1 and type 2 control circuits, a hysteresis comparator circuit, and a differential-to-single-ended converter circuit. The common-mode converter circuit compresses the input signal with a wide common-mode range; the pre-amplifier circuit identifies and amplifies the compressed differential signal; the type 1 and type 2 control circuits control the operating mode of the MLVDS receiver; the hysteresis comparator introduces hysteresis while amplifying the differential signal, suppressing differential noise and providing anti-interference capability; the differential-to-single-ended converter circuit converts the differential signal to a single-ended signal. This invention provides an MLVDS receiver circuit based on BiCMOS technology. This circuit, implemented using BiCMOS technology, can achieve a wide common-mode range input through a resistor divider network, and simultaneously implements both type 1 and type 2 operating modes, meeting the requirements of the MLVDS standard.

The application belongs to the technical field of power electronics, and relates to a CM-DM integrated active EMI filter with adjustable common-mode and differential-mode attenuation, comprising: a first noise attenuation circuit and a second noise attenuation circuit; the first noise attenuation circuit and the second noise attenuation circuit are both composed of a detection link, an amplification link and an injection link; the application takes a negative bus as a reference, two operational amplifiers use the same power supply system, and common-mode and differential-mode noises can be simultaneously and effectively attenuated through constructing a proper compensation current path, and common-mode and differential-mode insertion losses can be respectively changed by changing the gains of the first and second noise attenuation circuits; therefore, the application realizes the separate adjustment of common-mode and differential-mode noise attenuation capabilities.

This application relates to a current-mode digital active EMI filtering method and circuit based on switching spectrum analysis and reconstruction. The method includes: obtaining the initial common-mode noise data and initial differential-mode noise data of the Buck circuit at the switching frequency points; constructing a common-mode equivalent circuit and a differential-mode equivalent circuit including noise sources, compensation voltage sources, compensation capacitors, parasitic capacitors, and LISN impedances, calculating the initial compensation voltage common-mode data and initial compensation voltage differential-mode data at each frequency point to obtain the initial compensation voltage data; synchronously outputting the initial compensation voltage data through a DAC for initial noise compensation; measuring the noise voltage on the LISN as the noise source voltage, calculating the secondary compensation voltage data, and performing superposition iteration on the compensation voltage data. It is suitable for scenarios mainly with common-mode noise, and can achieve composite suppression of common-mode and differential-mode while detecting without detection and reducing the volume, and continuously optimize the EMI suppression effect through iterative update.