86 results about "Differential mode noise" patented technology

A network, network connector and method are provided for transmitting power and data signals between device nodes. The network utilizes a trunk cable in which a pair of power conductors and a pair of signal conductors are embedded in an insulative cover. The connector makes contact with the power and signal conductors during installation, such as by contact members which pierce the insulative cover of the cable. The connector has a base portion and an interface portion fitted to the base portion. A capacitor is disposed in the base portion and electrically coupled across the power conductors when the connector is installed. A node device is coupled to the cable via the interface module. When the device draws power from the cable, the capacitor limits perturbations of the supply voltage to reduce differential mode noise on the signal conductors.

A voltage adapter characterized by an advantage of reducing unnecessary power loss induced in standby mode operation and conserving the overall power consumption accordingly. The voltage adapter according to the present invention receives an input voltage and converts the input voltage into an output voltage having a voltage level different from the input voltage, and comprises an EMI filter for suppressing a differential mode noise in the input voltage, a bridge rectifier for performing a full-wave rectification to the input voltage, a transistor switch, a driver for controlling on / off operations of the transistor switch according to a feedback amount derived from the output voltage, and a circuit box for providing a discharge path for the EMI filter, while sampling the input voltage to detect a variation of the input voltage.

A system for processing a sound input to a MEMS microphone in a voice communication device, such as a cellular telephone. The system includes the microphone and a processing microchip. The processing microchip includes a differential receiver that receives the signal output of the microphone on one input and a voltage that biases the microphone on the other input. The output of the differential receiver represents the audio signal from the microphone, while noise signals induced on connections between the microphone and microchip are received equally on the differential receiver inputs, thereby cancelling. Further, the processing microchip also includes a bias voltage generator circuit for supplying a bias voltage to the microphone. Noise that is coupled onto or is inherent in the bias voltage generator circuit or couples onto the signal path from the bias voltage generator to the microphone will traverse substantially symmetrical paths to the differential receiver. This noise will also cancel at the receiver. Thus, the system provides a high fidelity rendering of sound input to the microphone while mitigating interference from noise.

An anti-noise-interference high-voltage side gate driving circuit comprises a high-voltage level shifting circuit, an RS latch and a driver, the high-voltage level shifting circuit converts the two input low-voltage pulse signals into two high-voltage pulse signals to be output, the two high-voltage pulse signals are respectively processed and then enter the RS latch, the RS latch outputs the signals into the driver, and the driver outputs a driving signal to control an external power tube be to switched on and off. According to the anti-noise-interference high-voltage side gate driving circuit, the high-voltage level shifting circuit is improved, the improved high-voltage level shifting circuit comprises two completely-same independent parts, and each independent part comprises two LDMOSs, a delay unit, a Zener voltage regulator tube, a capacitor, a resistor and a middle-voltage PMOS. The circuit can remove d(i)V( / i) / dt interference noise and differential mode noise, the transmission of normal signals is not affected while the noise interference is removed, and meanwhile the allowable negative VS voltages are increased.

The invention discloses a common mode noise and differential mode noise separator used for conductive electromagnetic interfere noise, which comprises a radio-frequency transformer (T) with a centretap and with transformation ratio of 2:1, a common mode choke (L), a differential mode filter capacitor (C) and a double-pole double-throw switch; the separator is characterized in that the differential mode filter capacitor (C) is connected with the primary side of the radio-frequency transformer (T) in parallel, a common mode output is connected at the centretap of the primary side of the radio-frequency transformer (T); secondary sides of the radio-frequency transformer (T) are connected with two output ends of the common mode choke (L) respectively; a differential mode signal is output via an output end of the common mode choke (L), meanwhile, the other end of the common mode choke (L) is grounded and forms a circuit; the double-pole double-throw switch controls the opening and closing of a parallel circuit of the radio-frequency transformer (T) and the differential mode filter capacitor (C) and a coupling loop of the radio-frequency transformer (T) and the common mode choke (L); The double-pole double-throw switch puts through S1 and the common mode is output, which is called a common mode separator. The double-pole double-throw switch puts through S2 and the differential mode is output, which is called a differential mode separator.

The invention provides a high-voltage side gate drive circuit capable of resisting noise interference. The high-voltage side gate drive circuit comprises a high-voltage level shift circuit, a differential-mode noise elimination circuit, an RS trigger and an output drive level circuit, wherein a low-side pulse signal is converted into a high-voltage pulse signal for output through the high-voltage level shift circuit; a common mode noise elimination circuit is connected between the output of the high-voltage level shift circuit and the input of the differential-mode noise elimination circuit; the common mode noise elimination circuit is used for eliminating a common mode noise signal generated in application; and the differential-mode noise elimination circuit eliminates the differential-mode noise introduced by process variations, outputs a normal pulse signal, reduces the normal pulse signal into a normal square signal through the RS trigger, outputs the square signal from the output drive level circuit and drives an external high-side power tube.

An inductor (160) includes a core (162) that has a window (164). The core (162) includes a first core member (168) and a second core member (170). A first winding (176) is coupled to the first core member (168) and a second winding (178) is coupled to the second core member (170). A cross-member (172, 174) is coupled at least partially across the window (178) and is conductively enabling flux flow between the first core member (168) and the second core member (170). An electronic circuit (100) includes an input terminal (118), an inductor (102), and an output terminal (E′, F′). The inductor (102) is coupled to the input terminal and has only a single inductive core (162). The inductor (102) is coupled to filter both common-mode noise and differential-mode noise. The load terminal is coupled to and receives filtered common-mode and differential-mode current from the inductor (102).

The invention discloses a soft separation method of conducted electromagnetic interference noise based on a blind signal processing technology, belonging to the field of conducted electromagnetic interference noise inhibition. The method comprises the following steps of: carrying out probe frequency spectrum estimation and compensation on two current probes; simultaneously measuring electromagnetic interference noise time domain signals on a live wire and a middle wire of an electronic system by the two current probes and a double-trace oscilloscope; carrying out blind separation on electromagnetic interference noise by utilizing a Fast ICA (Independent Component Analysis) algorithm in a blind signal processing method to obtain a signal source vector estimation value; and finally, judging the property of separation signals based on the maximum cross correlation coefficient of blind separation signals and common mode or differential mode reference signals. The invention overcomes the defects of using a radiofrequency transformer or a power divider to carry out hard separation on common mode noise and differential mode noise, has the advantages of high separation accuracy and favorable practicability, and lowers the cost.

A broadband filter filtering noise over a first conductive wire, a second conductive wire, and a third conductive wire includes a differential-mode filtering circuit connected to both the first conductive wire and the second conductive wire and a common-mode filtering circuit connected to both the first conductive wire and the second conductive wire. The differential-mode filtering circuit includes two inductors and two capacitors for filtering differential-mode noise of different frequencies. The common-mode filtering circuit includes two inductors and six capacitors filtering common-mode noise of different frequencies.

A receiving circuit of an RS 485 receiver is provided. The receiving circuit includes a first stage fully-differential amplifier, a second stage fully-differential amplifier, a bi-directional hysteresis comparator and an output controller which are connected in series with one another, wherein the first stage fully-differential amplifier adjusts common-mode electrical level, the second stage fully-differential amplifier amplifies differential-mode electrical level, and the output controller controls output through enabling. When receiving is enabled, the receiver performs output normally, and when receiving is disabled, the receiver outputs high electrical level, and therefore, common-mode noise and high-frequency differential-mode noise can be greatly suppressed, and receiving sensitivity can be improved.

The invention discloses a noise interference-proof high-side gate drive circuit. The circuit mainly comprises a common mode noise interference-proof high-voltage level displacement circuit, a pulse filtering circuit, an RS trigger and an output drive stage circuit, wherein the low-side low-voltage pulse generating signals are converted into high-side high-voltage pulse generating signals through the common mode noise interference-proof high-voltage level displacement circuit which can eliminate the common mode noise in the application at the same time; the pulse filtering circuit is used for filtering the residual differential mode noise component, the pulse signals for normal working are only maintained and returned to normal signals through the RS trigger; and then the normal signals are output as square signals through the output drive stage circuit to drive an external high-side power tube.

The invention relates to a radiation noise test method applied to a power line communication network. The method comprises the following steps of: extracting a first noise voltage of a live wire to a grounding wire and a second noise voltage of a neutral wire to the grounding wire in the power line communication network through a linear impedance stabilizing network to obtain a conducted noise in the power line communication network; calculating a vector sum and a vector difference for the first noise voltage and the second noise voltage through a noise separation network to obtain a differential mode noise voltage and a common-mode noise voltage so as to separate a differential mode conducted noise voltage from a common-mode conducted noise voltage; dividing the common-mode noise voltage by 50 ohms to obtain a common-mode noise current; and obtaining a radiation noise electric field emitted to a free space according to the common-mode noise current. The conducted noise is separated into a common-mode noise and a differential mode noise to obtain the relation between the radiation noise and the common-mode noise current so as to simplify test equipment and reduce test cost.

There is disclosed a switching mode power supply with a reduced EMI effect, comprising a rectifier for converting an AC power supplied by an AC power source into a rectified DC power, a transformer coupled to the rectifier for inputting the DC power from a primary winding and inducing a rectified power to a secondary winding through the primary winding, a switch unit connected in series with the primary winding for converting the DC power supplied to the primary winding into AC power by on / off operations, an output voltage feedback control circuit for providing pulses to drive the switch unit by controlling a switching duty cycle of the switching unit, and a power line filter including a unidirectional current-limiting device such as a diode for reducing differential mode noise appearing between a live supply line and a neutral line from the alternating current power source.

A common mode noise filter includes: a common mode filter inserted into a pair of signal lines; and a pair of capacitively coupled coils having one ends connected respectively to the corresponding signal lines and the other ends opened. According to the present invention, common mode noise can be removed by a common mode filter, as well as, differential mode noise in a desired frequency band can be removed by a pair of coils whose other ends are opened.

The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a differential mode noise signal is received at a first and a second input port, which are connected via a first and a second resistor to a first and a second end tap of a primary coil of a transformer, respectively. The transformed differential mode noise signal is then transmitted via a first and a second end tap of a secondary coil of the transformer and a third and a fourth resistor to a first and a second output port for injection at high impedance into a first and a second wire of the communication link. Optionally, the device comprises a third input port connected to a center tap of the secondary coil for receiving a common mode noise signal. The common mode noise signal is then provided at low impedance to the first and the second wire via the first and the second end tap of the secondary coil and via the third and fourth resistor having low impedance, respectively. The device allows injection of a noise signal into the communication link at a desired location without splitting the same. Furthermore, the device allows injection of differential mode noise signals and common mode noise signals using same circuitry without switching and / or rewiring between different electrical circuits.

The invention discloses an electromagnetic compatibility anti-interference system of a DC (Direct Current) motor. The electromagnetic compatibility anti-interference system of the DC motor comprises a transformer, a first-level shielding line, a rectifier filter and control circuit, a first-level filter circuit, a second-level shielding line, a second-level filter circuit and the DC motor, wherein a secondary coil of the transformer is connected with an input end of the rectifier filter and control circuit through the first-level shielding line; an output end of the rectifier filter and control circuit after passing through the first-level filter circuit then passes through the second-level filter circuit through the second-level shielding line and is then connected with a power input end of the DC motor. The electromagnetic compatibility anti-interference system of the DC motor, provided by the invention, has the advantages of strong electromagnetic interference suppression capability, good suppression effects, and capabilities of not only suppressing common mode and difference mode noise transferred from an electric grid and external electromagnetic radiation interference, but also preventing electromagnetic interference from the DC motor to surrounding electronic devices and communication systems; and the electromagnetic compatibility anti-interference system of the DC motor is reliable and practical, is not only convenient to produce, but is also wide in application foreground, very low in cost and suitable to popularize widely.

A memory array of dual part cells has a pair of twisted write bitlines and a pair of twisted read bitlines for each column. The twist is made by alternating the vertical position of each bitline pair in each section of a column, with the result of generating common mode nose and of reducing differential mode noise.

A memory array of dual part cells has a pair of twisted write bitlines and a pair of twisted read bitlines for each column. The twist is made by alternating the vertical position of each bitline pair in each section of a column, with the result of generating common mode nose and of reducing differential mode noise.

The invention discloses a conductive common-mode / differential-mode noise separation method, belonging to the technical field of conductive electromagnetic compatibility noise measurement. Radiofrequency current probe measurement and software separation calculation are combined, and the method is suitable for conductive interference measurement on a single phase line. The method comprises the following measuring steps: I, directly measuring a phase line, center line and common-mode conducted interference spectrum by using a radiofrequency current probe, connecting the output end of the current probe to a spectrometer through a coaxial line, and driving the spectrometer to work in a peak detection mode; II, calibrating interference spectrum data obtained in the step I, and measuring the transmission admittance of the current probe and the coaxial line used in the step I by using a vector network analyzer; III, putting the corrected data IL, IN and ICM into a formula to obtain a differential-mode current spectrum IDM so as to obtain the interference voltage in a differential mode and a common mode. By adopting a test method, the conducted interference spectrum on each line can be measured rapidly, and separation of common-mode and differential-mode interference is realized. The method is mainly applied to online measurement of electromagnetic compatibility noise.

The invention discloses a level shift circuit capable of suppressing noise, comprising a floating power supply, a dipulse generation circuit, a high-voltage level shift circuit, an undervoltage detection circuit, an RS latch circuit, a drive circuit, a differential mode current detection circuit and a differential mode noise elimination circuit, wherein the differential mode current detection circuit is used for suppressing a common mode current signal output by the high-voltage level shift circuit, detecting a differential mode current signal, converting the differential mode current signal into a differential mode voltage signal and outputting the differential mode voltage signal to the differential mode noise elimination circuit; and the differential mode noise elimination circuit is used for receiving the differential mode voltage signal output by the differential mode current detection circuit, eliminating differential mode noise introduced by the mismatching of the high-voltage level shift circuit, converting the differential mode voltage signal into a high-end reset signal and a high-end position signal and outputting the two signals to the RS latch circuit. The invention not only can be used for suppressing the common mode noise, but also can be used for eliminating the differential mode noise and has the advantages of simple circuit structures, chip area saving and convenient popularization and use.

The invention discloses a filter circuit of a high-voltage drive circuit and a high-voltage drive circuit. The filter circuit comprises a first inverter, a second inverter, a first delayed filter circuit, a second delayed filter circuit, a first NOR gate, and a second NOR gate. The first inverter receives a first level shifting signal and outputs a first inverting signal; the second inverter receives a second level shifting signal and outputs a second inverting signal; the first delayed filter circuit receives the first inverting signal and the second inverting signal respectively and outputs a first short time-delay signal and a second short time-delay signal; and the second delayed filter circuit receives the second inverting signal and the first inverting signal respectively and outputs a first long time-delay signal and a second long time-delay signal. The first NOR gate receives the first short time-delay signal and the first long time-delay signal and outputs a first NOR signal; and the second NOR gate receives the second short time-delay signal and the second long time-delay signal and outputs a second NOR signal. According to the filter circuit, the capability of filtering differential mode noises is enhanced while the common-mode noises are filtered and the noise filter efficiency is improved.

The invention belongs to the research field of power electron and electromagnetic interference and discloses a common mode / differential mode noise discrimination network. The network comprises two line transformators which are in parallel connection, the driving point impedances of the two line transformators are both100 omegas so that Zin1=Zin2=50 omega is precisely guaranteed and the network can better play the role of the frequency bandwidth of the line transformators; meanwhile, a compensation capacitor is added to ensure that the driving point impedances of the common mode / differential mode noise discrimination network are kept within 50 omegas. The common mode / differential mode noise discrimination network can reach impedance matching of separate meshes, realizes that the network always keeps the characteristic impedance of 50 omegas in the 30 MHz broad band, and can be applied to various common mode / differential mode separations which can conduct electromagnetic noise.

An electromagnetic interference (EMI) filter includes a first magnetomotive element, a first wire, a second wire, and a second magnetomotive element. The second magnetomotive element forms a closed magnetic loop, which comprises a first portion penetrating a through hole of the first magnetomotive element. Thus, the first wire and the second wire in the Filter filter not only differential mode noise but also common mode noise.

The invention relates to a method for effectively solving in-phase interference of a contactor and a microcontroller and solves the in-phase interference of the contactor and the microcontroller through designing a noise processing circuit. Before an alternating current power supply passes through a bridge rectifier circuit, high-frequency noise and differential mode noise in the alternating current are removed through a capacitance network and a choking coil; after the voltage subjected to high-frequency noise and differential mode noise filtering passes through inductance and capacitance networks, rest high-frequency interference signals and common-mode noise in the current are removed, and the voltage supplies electricity to an MCU (micro control unit); and a TVS (transient voltage suppressor) diode is switched into the power supply end of the MCU, and the impact of surge current such as lightning and charges on a machine case is effectively inhibited. The method has the advantages that the cost is low, the application is wide, and the work is reliable.

The invention relates to a high-voltage direct-current filtering device, comprising a filter circuit unit, a high-voltage bleeder circuit unit, a high-voltage direct-current positive and negative electrode input terminal and a high-voltage direct-current positive and negative electrode output terminal. The filter circuit unit comprises a common-mode filter circuit and a differential-mode filter circuit, and the high-voltage bleeder circuit unit comprises a bleeder branch; The positive and negative input terminals of the common mode filter circuit are connected with the positive and negative input terminals of the high voltage direct current, and the positive and negative output terminals of the common mode filter circuit are connected with the differential mode filter circuit. The differential mode filter circuit comprises a differential mode filter capacitor and a differential mode filter inductor, A positive electrode and a negative electrode of the differential mode filtering capacitor are connected to a common mode filtering circuit, a first connection terminal of the differential mode filtering inductor is connected to the negative electrode of the differential mode filteringcapacitor, a bleeding branch is connected between the positive electrode and the negative electrode of the differential mode filtering capacitor, and the positive electrode of the differential mode filtering capacitor and the second connection terminal of the differential mode filtering inductor are respectively connected to the output terminals of the positive electrode and the negative electrodeof the high voltage direct current. The invention improves the quality of the DC power supply by filtering the common-mode noise and the differential-mode noise output by the high-voltage DC power supply.

The invention discloses a novel network filter circuit, comprising a common mode rejection unit, a high frequency common mode noise and differential mode noise filtering unit, a signal coupling and electric isolation unit, and a low frequency common mode noise filtering unit. And output end of the common mode rejection unit is connected with an input end of the high frequency common mode noise and differential mode noise filtering unit. An output end of the high frequency common mode noise and differential mode noise filtering unit is connected with an input end of the signal coupling and electric isolation unit. An output end of the signal coupling and electric isolation unit is connected with an input end of the low frequency common mode noise filtering unit. The novel network filter circuit has the advantages of low manufacturing cost, little manufacture variation, stable quality and so on.