319 results about "Common-mode interference" patented technology

The invention discloses an online multi-channel rapid gas chromatographic analysis system and method, particularly relates to the technical field of gas chromatographic analysis, and is used for solving the problems of baseline noise rise and trace component detection precision reduction caused by physical coupling and signal interference when multiple detectors work in parallel in the prior art. Interference signal features of adjacent detection channels are extracted, a chaotic or linear compensation signal is dynamically generated in combination with harmonic primary and secondary sorting and recursive quantization factor analysis, and common-mode interference of a target channel is suppressed. Electromagnetic isolation parameters of a shielding structure are adjusted in real time based on the baseline signal after noise suppression, and accurate matching of impedance and interference spectrum is achieved; further separating time domain overlapped signals and analyzing asymmetric distortion characteristics, and eliminating system errors through normalization calibration; dynamic interference suppression, electromagnetic shielding optimization and signal distortion traceability are combined, the anti-interference capability and analysis precision of multi-channel detection are remarkably improved, and the method is suitable for high-throughput rapid detection scenes of complex samples.

The invention discloses a high-voltage circuit for an electric flame stove. The high-voltage circuit comprises a PFC circuit, a high-frequency conversion circuit, a boosting transformer, an energy coupling circuit and a voltage doubling circuit which are electrically connected in sequence. According to the EMI filter circuit, common-mode interference and differential-mode interference are filtered out, and pure alternating current input is provided for a back-end PFC circuit; two chips are adopted in the PFC circuit, so that the PFC circuit 300 finally realizes the consistency of the current waveform and the voltage phase; in the other embodiment of the invention, double chips are adopted, so that'fault linkage protection 'is realized; stable discharging of multiple groups of positive and negative electrodes is achieved through multiple groups of single energy coupling capacitors and independent voltage doubling rectifier bridges which are connected in parallel.

The invention relates to the technical field of optical fiber sensing, and discloses an optical fiber sensing signal adaptive demodulation analysis method for inhibiting common-mode interference, which comprises the following steps of: synchronously acquiring an original signal of a main sensing optical fiber channel and a common-mode interference signal of a reference optical fiber channel, and performing time-frequency conjoint analysis on the signal of the reference optical fiber channel to obtain a common-mode interference signal; s2, extracting an interference spectrum component containing temperature drift and light source fluctuation characteristics, constructing a hybrid adaptive filter bank which comprises a recursive least square (RLS) filter and a variable step size least mean square (LMS) filter which are connected in parallel, and dynamically adjusting a forgetting factor of the RLS filter and a step size factor of the LMS filter based on the interference spectrum component extracted in the step S2, according to the optical fiber sensing signal adaptive demodulation analysis method for suppressing common-mode interference, a parameter adjustment strategy is continuously optimized, a pure vibration signal with an output signal-to-noise ratio is improved, and the effect of accurately suppressing common-mode interference in real time is achieved.

The present application relates to the field of solution measurement, in particular to an electrode conductivity sensor conductivity measurement circuit and method, first, the AC excitation generation module generates an amplitude and frequency adjustable AC sine excitation signal under the control of the single-chip microcomputer; then the AC sine excitation signal passes through the precision resistor R0 and the conductivity cell of the electrode sensor to the system ground in turn; then the differential amplification circuit differentially amplifies the voltage between the precision resistor R0 and the electrode sheet of the conductivity cell; the amplified voltage signal is collected by the ADC, and then the voltage data is transmitted to the single-chip microcomputer; finally, the single-chip microcomputer can obtain the conductivity of the solution after the collected voltage data is operated. The present application directly collects the peak and valley voltage values of the AC signal, subtracts to obtain the amplitude of the AC signal, and does not need a rectification filter circuit to detect the amplitude of the AC signal, which can quickly respond to the change of the solution conductivity, eliminates the influence of common-mode interference factors, and simplifies the circuit design.

The invention provides an automobile wire harness short circuit fault detection method, system and device and a medium, and the method comprises the steps: extracting the transient characteristic quantity of a current signal of each monitoring node, and obtaining the amplitude attenuation characteristics of the current signal of each monitoring node in a wire harness propagation process based on the mutual information intensity inversion of the transient characteristic quantity between adjacent monitoring nodes; further identifying an abnormal wire harness path which is obviously influenced by common-mode interference based on the fluctuation difference degree of the amplitude of the common-mode current between adjacent monitoring nodes in spatial distribution, and constructing a common-mode interference topological graph which represents the abnormal state of the wire harness in combination with the response intensity of the common-mode current; and performing fuzzy reasoning on the short-circuit fault probability of each monitoring node according to the amplitude attenuation characteristics corresponding to each monitoring node and the common-mode interference topological map to obtain the fault membership degree of each monitoring node, and performing short-circuit fault correlation positioning on the target automobile wire harness through all the fault membership degrees. By adopting the scheme of the invention, the associated positioning of the short-circuit fault of the automobile wire harness under the common-mode interference condition can be realized.

The embodiment of the invention provides a power transmission system and a power generation system. The power transmission system comprises: a power conversion circuit for performing power conversion on an input electric signal; the filter circuit comprises a first filter circuit and a second filter circuit, and the first filter circuit is coupled between the input end of the power transmission system and the input end of the power conversion circuit; the second filter circuit is coupled between the output end of the power conversion circuit and the output end of the power transmission system; one end of the bridging capacitor bank is coupled with the input end of the power transmission system, and the other end of the bridging capacitor bank is coupled with the output end of the power transmission system, so that a loop is formed, and interference signals in the electric signals output by the output end of the power conversion circuit can flow back to the input end of the power conversion circuit. According to the embodiment of the invention, the interference signal can flow back, the common-mode interference current at the input end and / or the output end is reduced, a safety Y capacitor does not need to be adopted, the size of the filter inductor can be reduced, and the cost is reduced.

The invention provides a silicon carbide MOS drive control chip overcurrent protection method and device, and the method comprises the steps: setting a forward sampling channel and a reverse sampling channel at a source sampling resistor, setting different sampling time windows for different sampling channels, carrying out the peak shifting setting of the time windows of the double sampling channels, and carrying out the peak shifting setting of the time windows of the double sampling channels, thereby achieving the overcurrent protection of a silicon carbide MOS drive control chip. The time period with the strongest common-mode interference can be avoided; meanwhile, the switching speed of the silicon carbide MOS device is mapped into a theoretical common-mode interference waveform, and the waveform and a bidirectional sampling signal are synthesized, so that a common-mode interference component in the sampling signal can be accurately separated, and the synthesized current signal is more accurate; on the basis, current signals are compensated by combining on-resistance change caused by junction temperature change, and overcurrent protection is carried out by adopting a graded protection strategy. According to the method, the influence of common-mode interference on current sampling is effectively overcome through peak shifting design on sampling channel time and common-mode interference separation based on switching speed.

The invention discloses an active pen and touch screen interaction system resistant to common-mode interference and a signal demodulation method. The system comprises a signal receiving terminal and a signal transmitting terminal. The signal transmitting terminal modulates data to be transmitted by adopting a differential binary phase shift keying modulation method, and transmits a generated modulation signal to the signal receiving terminal; the analog front-end receiving module is coupled with the signal transmitting terminal, receives the modulation signal and outputs a digital square wave signal after fidelity extraction processing; and the digital demodulation processing module performs differential coherent digital demodulation on the digital square wave signal based on the prior characteristics of the modulation signal, inhibits residual noise and recovers data to be sent. The analog front end focuses strong common-mode noise suppression and analog filtering, the digital demodulation algorithm performs secondary digital purification by using signal time sequence characteristics, and the two constructs an efficient anti-interference pipeline. Meanwhile, the regular square wave signals can be directly processed through differential coherent demodulation, and the requirements for performance and power consumption of a rear-end processor are lowered.

The invention discloses an anti-interference system for a slip ring communication technology, and belongs to the technical field of communication. Aiming at the problems of electromagnetic interference, mechanical vibration and unstable contact of monocrystalline silicon furnace equipment, a collaborative solution is provided. The system comprises a conductive slip ring assembly, a dynamic shielding module, an asymmetric differential transmission module, an intelligent filtering module, an environment sensing module and a contact impedance compensation module, and real-time cooperative control is realized through a bus controller. The dynamic shielding module adopts a liquid metal micro-channel layer and a piezoelectric driving layer, the shielding density is dynamically reconstructed according to the electromagnetic interference frequency band and the vibration intensity, and broadband noise is suppressed; the asymmetric differential transmission eliminates common-mode interference through dynamic phase compensation; the intelligent filtering module adaptively adjusts parameters of a band elimination filter based on a deep learning model, and accurately suppresses time-varying interference; the carbon nanotube composite electric brush stabilizes contact impedance through a pressure feedback mechanism. The system is obviously superior to a traditional static shielding and fixed filtering scheme, and reliable communication requirements are guaranteed.

The invention provides a novel broadband simulation multiple correlation type microwave radiometer, and relates to the technical field of passive remote sensing detection. The system comprises a double-path correlation radio frequency front-end unit, an intermediate-frequency filtering and amplifying unit and an analog multiple correlation unit, wherein the analog multiple correlation unit comprises two analog multiple correlation channels, each analog multiple correlation channel comprises a broadband multiplication unit and an active differential filtering unit, and the broadband multiplication units are used for carrying out differential conversion on input same signals and orthogonal signals and carrying out correlation operation; and performing active differential filtering processing on the signal after the correlation operation through an active differential filtering unit, and outputting two paths of orthogonal differential parameters. The analog multiple correlation unit designed by the invention adopts a full-link differential design, including differential passive / active filtering, amplification and transmission, the design can provide amplitude twice as large as that of a single-ended signal and better linearity under the same power supply voltage, and meanwhile, the problems of direct-current drift and common-mode interference suppression are solved.

The invention relates to a current-to-voltage acquisition circuit for suppressing common-mode interference. The current-to-voltage acquisition circuit comprises a current amplification module, a current transformer, a high-pass filter, an interference acquisition module, an interference analysis module and a suppression execution module, by means of the design, the common-mode interference suppression effect is better than that of a traditional sampling circuit, errors caused by sampling signal deviation generated by interference are avoided to the maximum degree, the common-mode interference suppression circuit is particularly suitable for interference scenes or occasions where interference sources change, the changed interference sources can be calculated in a sampling statistics mode, and the interference source suppression effect is improved. Therefore, the suppression ratio of common-mode suppression is adjusted, and the environment condition is dynamically tracked to obtain an accurate sampling effect.

The invention discloses a broadband electromagnetic radiation interference characteristic modeling method for a shielding cable network. The method comprises the following steps: 1) obtaining a scattering parameter matrix of a shielding connector and a transmission parameter matrix of a bent shielding cable; 2) constructing an equivalent N port model of the shielding connector by using the scattering parameter matrix, and deducing a transmission parameter matrix of the shielding connector; 3) establishing a multi-conductor transmission line equation reflecting the distribution of interference current on the shielding cable by using the shielding cable transfer impedance; 4) cascading the transmission parameter matrixes of all the bent shielding cables and the shielding connectors to obtain an overall transmission parameter matrix of the shielding cable network; and 5) solving the multi-conductor transmission line equation in combination with the boundary constraint condition to obtain the common-mode interference current of the shielding layer of the shielding cable, and calculating the electric field radiation of the shielding cable network through the dipole array theory. The method is suitable for uniform and non-uniform shielding cables and shielding cable networks of single-core and multi-core wire harness shielding wire types, and has good universality.

The invention relates to the field of power electronic devices, in particular to an all-fiber isolation SiC MOSFET grid driver suitable for ultrahigh voltage and application, the all-fiber isolation SiC MOSFET grid driver comprises a transmitting side, a fiber group and a receiving side which are connected in sequence, the transmitting side comprises a constant-current laser driver, a semiconductor fiber coupling laser, a fiber coupler of an FC connector, a high-speed light emitter driver and a light emitter, and the receiving side comprises a high-speed light emitter driver and a high-speed light emitter. The optical fiber group comprises a quartz power optical fiber and a plastic signal optical fiber of an FC (Fiber Channel) joint, and the receiving side comprises a beam expander, a laser battery, a 5V boost IC (Integrated Circuit), a 25V boost IC, an optical receiver, a non-isolated driving IC and a push-pull current expanding circuit. And common-mode interference caused by a coupling capacitor is eliminated. Meanwhile, the efficiency of a device is reasonably calculated, and a high-efficiency boost IC is matched, so that the driving power of 0.8 W is realized, and a 6.5 kV 25A high-voltage SiC MOSFET module can be driven to work at the switching frequency of more than 100kHz.

The invention discloses a CAN bus activity detection and wake-up circuit and method, and belongs to the technical field of CAN bus communication, the CAN bus activity detection and wake-up circuit comprises a CAN bus interface circuit, a signal detection and processing circuit and a controller, the input end of the CAN bus interface circuit is connected with a CAN bus; the signal detecting and processing circuit comprises a voltage comparator, the non-inverting input end and the inverting input end of the voltage comparator respectively receive a CANH signal and a CANL signal which are electrically isolated by the CAN bus interface circuit, and the output end of the voltage comparator is connected to a wake-up pin of the controller; the controller is used for monitoring the level state of the wake-up pin, and when the level of the wake-up pin is in an effective state, the electronic equipment is controlled to be switched from the sleep mode to the normal working mode. By introducing an electrical isolation and voltage difference detection mechanism, the problem of false wake-up caused by common-mode interference or bus noise in the prior art is solved, and reliable wake-up under low power consumption is realized.

The invention provides an intelligent current sensor and method, and the method comprises the steps: carrying out the state offset estimation of the current monitored by sensor nodes according to the time-space relation between sensor nodes, and obtaining the state offset of the current of the sensor nodes; extracting the electromagnetic interference quantity of each sensor node from the electromagnetic interference information, and determining an electromagnetic coupling coefficient of common-mode interference between the sensor node and other sensor nodes according to the array relationship between the sensor nodes and all the electromagnetic interference quantities; determining the interference compensation amount of each sensor node current through the state offset of the sensor node current and all the electromagnetic coupling coefficients; and when the state offset of the current of the sensor node is greater than a preset offset threshold value, adaptive compensation is carried out on the monitored current according to the interference compensation amount to obtain a compensation current. By adopting the scheme of the application, adaptive compensation of the intelligent current sensor to the monitored current data can be realized, so that the measurement reliability of the multi-phase power system is improved.

The invention discloses a diagnosis and measurement system for an electromagnetic compatibility experiment and a matched rectification system. The diagnosis and measurement system comprises a broadband LISN, a difference and common mode interference separation module, a radiation emission interference positioning module, ultra-wideband current calipers, a system power supply line rectification assembly and a system internal interconnection cable rectification assembly. The system provides stable impedance through a broadband LISN, samples high-frequency and low-frequency interference signals by using a difference and common mode interference separation module and a current caliper, and separates a difference mode component from a common mode component. And the radiated emission interference positioning module detects equipment radiation leakage points and generates a shielding effectiveness report. The rectification assembly quickly solves the electromagnetic compatibility problem of the equipment, and ensures that the test standard is met. The system realizes efficient and accurate electromagnetic interference detection and rectification.

The invention discloses an electric leakage detection method based on wavelet transform harmonic suppression, and the method comprises the steps: synchronously collecting a current signal through a dual-channel differential sampling circuit, and obtaining two paths of differential voltages; after common-mode interference is eliminated through differential amplification and impedance matching, low-pass filtering and digital conversion are carried out; extracting signal multi-scale energy characteristics by using wavelet decomposition, and setting a threshold value to separate leakage low-frequency components from high-frequency noise; a pure electric leakage signal is obtained through inverse wavelet reconstruction, and a high-speed switching circuit compares a preset threshold value to trigger a protection action. According to the scheme, differential sampling, impedance matching and wavelet analysis technologies are combined, the signal-to-noise ratio and the detection precision are effectively improved, the problems that in the prior art, electric leakage signals are prone to interference and slow in response speed are solved, and the reliability and the real-time performance of electric leakage protection are remarkably improved.

The invention discloses a signal high-frequency interference resisting device and method for electrical resistance tomography. A high-frequency filtering unit in the device comprises a magnetic ring, a coaxial shielding line, a first resistor and a second resistor; the coaxial shielding lines are connected between the corresponding detection electrodes and the signal sampling ends, and the first resistors are connected between the first ends of the signal lines in the corresponding coaxial shielding lines and the first ends of the signal lines in the next coaxial shielding lines. The second resistor is connected between the second end of the signal line in the corresponding coaxial shielding line and the second end of the signal line in the next coaxial shielding line; the first end of the signal line in the coaxial shielding line is also connected with the first end of the shielding layer in the next coaxial shielding line; the magnetic rings sleeve the outer layers of all the coaxial shielding wires and are tightly attached to the outer layers of the coaxial shielding wires, filtering on a transmission line is achieved, the twisted-pair coaxial shielding wire magnetic rings are combined to serve as transmission wire harnesses, a hardware coupling filter circuit between the wire harnesses is constructed, the suppression effect of common-mode interference is improved, sampling signals are more real, and imaging is clearer.

The invention discloses a linear motor position detection method based on a space Hall element, belongs to the technical field of linear motors, and realizes high-precision position detection through cooperative work of a reference Hall element and a plurality of compensation Hall elements. The compensation Hall elements are distributed on the positive side and the negative side of the reference element in the axial direction in a non-equidistant gradient mode to form differential signal pairs to eliminate common-mode interference, and the sensitivity coefficient is dynamically adjusted by combining the axial distance An and the radial distance Ln. And the anomaly detection mechanism monitors the deviation value in real time, switches the redundant component group when the deviation value exceeds a threshold value and generates a fault diagnosis signal. According to the method, through a multi-dimensional signal fusion and dynamic compensation strategy, the detection precision, the anti-interference capability and the system reliability under complex working conditions are remarkably improved.

The invention relates to the technical field of temperature sensing, and provides a temperature sensor detection circuit and semiconductor temperature control equipment, and the circuit comprises a constant current source module which is used for providing constant current; the thermosensitive module is connected with the constant current source module, and the thermosensitive module is used for obtaining the constant current to form temperature detection voltage corresponding to the temperature; the input end of the multi-stage differential module is connected with the thermosensitive module, the output end of the multi-stage differential module is used for being connected with the analog-to-digital conversion module, and the multi-stage differential module is used for carrying out at least two-stage differential processing on the temperature detection voltage to form a detection output signal. The thermosensitive module outputs temperature detection voltage corresponding to the temperature under the action of constant current, the multi-stage differential module obtains the temperature detection voltage for differential processing, the influence of common-mode interference is reduced, the multi-stage differential module carries out at least two-stage differential processing, the common-mode interference is further removed, and an output detection output signal has the advantage of high precision. And the requirement of semiconductor production on temperature detection is met.

The invention discloses an output current sampling evaluation system for a double-shaft low-voltage motor driver. The output current sampling evaluation system comprises a single-resistance signal acquisition module, a common-mode interference suppression module, a double-shaft current separation module, a current parameter extraction module, a sampling precision evaluation module and an evaluation result integration module. The system collects bus current signals through a single resistor, interference is filtered out through a common-mode interference suppression module based on an equivalent common-mode circuit model, then double-axis current signals are separated out through a double-axis current separation module according to a single-resistor bus current sampling model, after characteristic parameters are extracted, precision data are generated through sampling precision evaluation, and the precision data are analyzed through an analysis module. And finally integrating into a comprehensive evaluation report. According to the system, the problems of insufficient biaxial coupling processing and lack of common-mode interference evaluation systematicness in traditional evaluation are solved, and the accuracy and comprehensiveness of biaxial current sampling evaluation are improved.

The invention discloses a driving power supply fault switching method and system, particularly relates to the technical field of power system relay protection, and is used for solving the problem that an existing relay power supply switching system causes misoperation due to common-mode interference caused by ground fault transient potential gradient. An earth screen potential gradient is collected in real time, a control cable orthogonal electric field component is measured synchronously, an electric field fiber bundle structure is reconstructed based on topology invariant distribution of a cable surface topology sequence substance, and a common-mode interference coupling coefficient is generated according to a space vector relation between an earth screen gradient direction and a reconstructed electric field; the coupling coefficient is converted into electrostrictive strain through the inverse piezoelectric effect, then a dynamic compensation voltage instruction is generated, finally, the compensation instruction is superposed to a power supply control loop to drive a standby power supply to be switched, the coupling influence of earth screen transient interference on a relay is eliminated from the physical mechanism level, the problem of misoperation is fundamentally solved, and the reliability of the relay is improved. And the reliability of power supply switching of the ultrahigh-voltage power transmission and transformation system is

The invention discloses an uninterruptible power protection device replacement system, and relates to the field of power protection devices. The sampling access module is used for connecting a current sampling loop of a temporary protection device to a secondary side of a current transformer in parallel through an isolation transmitter, and connecting a voltage sampling loop to a secondary side of a voltage transformer in parallel through a high-resistance isolation circuit; the parameter monitoring module is used for acquiring a temporary and old protection device homologous current phase difference and monitoring a common-mode interference voltage and an environment temperature change rate; the fusion calculation module is used for calculating a comprehensive protection coefficient; the locking control module is used for remotely locking an old protection device to enter a logic bypass when the comprehensive protection coefficient is stable and meets a preset condition; the safety monitoring module is used for monitoring residual leakage current and protection coefficient change in a logic bypass state; and the removal execution module is used for physically removing the old protection device and the wires when the conditions are met. The protection state is comprehensively evaluated by collecting operation parameters, the old protection device is remotely switched, the operation condition is continuously monitored, and the safety of the replacement process of the protection device is guaranteed.

The high-frequency electromagnetic flowmeter comprises an electromagnetic flow converter and an electromagnetic flow sensor, the electromagnetic flow converter is electrically connected with the electromagnetic flow sensor, and the electromagnetic flow converter comprises an A / D analog-to-digital converter, a differential amplifier, a single-chip microcomputer, an electronic switch group and a direct-current constant-current source. The electromagnetic flow sensor comprises a measuring conduit, a measuring electrode, a magnetic conductive piece, a temperature sensor and a magnet exciting coil; according to the electromagnetic flowmeter, the high-frequency three-valued rectangular wave is adopted as excitation current, a flow signal with the sampling frequency one time higher than the excitation frequency is generated through induction, and therefore the noise interference restraining capacity of the electromagnetic flowmeter is improved; by adopting a technical measure which is the same as that of suppressing power frequency interference by low-frequency rectangular waves, the purposes of amplifying flow signals and suppressing power frequency series mode interference and common mode interference are achieved, and the production cost is reduced; the temperature sensor is additionally arranged in the electromagnetic flow sensor, so that the high-frequency electromagnetic flow meter can compensate and correct measurement errors caused by temperature changes.

The invention provides an electromagnetic compatibility filter circuit of a three-phase positionless direct-current fan, and relates to the technical field of conduction and radiation suppression of the three-phase positionless direct-current fan, and the circuit comprises a three-stage differential-mode filter capacitor, a first-stage common-mode capacitor and a first-stage common-mode inductor which are connected with a power supply in parallel, the three-stage differential-mode filter capacitor is used for filtering differential-mode interference signals in a circuit, the common-mode capacitor and the common-mode inductor are used for providing a low-impedance loop for common-mode interference signals and filtering common-mode interference signals, and the three-stage differential-mode filter capacitor comprises a first differential-mode filter capacitor, a second differential-mode filter capacitor and a third differential-mode filter capacitor group. The first-stage common-mode capacitor comprises a first common-mode filter capacitor, and the first-stage common-mode inductor comprises a first common-mode inductor. According to the filter circuit, a three-stage differential mode circuit and a two-stage common mode circuit are combined, and the filter circuit can play a good role in inhibiting differential mode interference signals and common mode interference signals generated in a three-phase position-free direct-current fan power supply and a commutation circuit.

According to the station steel rail potential monitoring terminal disclosed by the utility model, through cooperative arrangement of the signal I / O unit, the data processing module and the server module, signals are collected from the steel rail through the signal I / O unit; the signals are subjected to scaling, filtering, common-mode interference removal and isolation processing, so that the accuracy and the stability of the signals are ensured; the data processing module carries out high-speed sampling on the processed signals and carries out data interaction with the server module through modes of 4G / CAT1, WIFI, 100M ETHERNET and the like, the average value, the maximum value and the minimum value of all sampling values are obtained, the sampling values are converted into physical values through the transformation ratio and the offset, data are uploaded to the server module through an MQTT protocol, high-frequency sampling is carried out on the steel rail potential signals, and the steel rail potential signals are sent to the server module. Proper data samples are provided for deep learning in the aspect of railway system management.

The application discloses a kind of satellite-borne infrared emissivity differential measurement method and device using cold black background, belong to spacecraft thermal control and material on-orbit testing technical field, purpose is to eliminate environmental stray radiation and conduction heat leakage interference, realize material emissivity high-precision in-situ on-orbit test.The application relies on deep space cold black environment and differential disturbance thought, supporting layout emissivity known standard unit and unit to be measured, make two in consistent light thermal condition, respectively establish transient heat balance equation.Because two kinds of units are consistent, such as common-mode interference of stray radiation, conduction heat leakage, two formula difference can be removed interference term, only keep and emissivity related radiation heat loss term.Through the design of different thermal control conditions (such as balance heating, constant temperature control, dynamic heating), the real emissivity of the material to be measured is solved.The application is suitable for in-situ, high-precision measurement of the infrared emissivity of spacecraft surface materials, especially intelligent thermal control materials such as thermochromic materials in space environment.

The application relates to the technical field of electrolytic cell monitoring, in particular to a lead electrolytic cell voltage online intelligent monitoring method and system, which comprises the following steps: collecting the cell voltage, electrolyte voltage and electrolyte temperature of a lead electrolytic cell at each moment in a monitoring interval; determining the induced common-mode interference condition of the monitoring interval, obtaining the electrolysis high-temperature interference condition of the monitoring interval; combining the induced common-mode interference condition and the electrolysis high-temperature interference condition to obtain a voltage interference factor of the monitoring interval; and respectively correcting the anode voltage drop, cathode voltage drop and electrolyte voltage drop of the lead electrolytic cell to evaluate the lead electrolytic cell voltage monitoring condition. Therefore, the accuracy and reliability of the lead electrolytic cell voltage monitoring are improved.

The invention relates to a totem pole bridgeless power factor correction module and device, a power supply and a power supply system, the power factor correction module is used for performing power factor correction on alternating current input by an alternating current power supply, and the power factor correction module comprises a first transistor, a second transistor, a third transistor, a fourth transistor and an inductor, a first adjusting assembly and a second adjusting assembly are connected to the third transistor and the fourth transistor in parallel respectively, at least one of the first adjusting assembly and the second adjusting assembly is a switch, and the switches in the first adjusting assembly and the second adjusting assembly are conducted before the transistors connected in parallel are switched on when the alternating current power supply crosses zero. According to the embodiment of the invention, the switches in the first adjusting assembly and the second adjusting assembly are configured to be switched on before the transistors connected in parallel when the AC power supply crosses zero, and the connection point of the third transistor and the fourth transistor can be slowly discharged, so that the common-mode switching speed is slowed down, the common-mode interference is reduced, and the leakage current peak is reduced.

The utility model provides a voiceprint sensor circuit of a combined power fan blade, which belongs to the technical field of fan blades and comprises a first differential mode interference elimination module, a second differential mode interference elimination module, a first common mode interference elimination module and a third differential mode interference elimination module, the first differential mode interference elimination module is used for eliminating differential mode static electricity, electrical fast transient pulse train and differential mode surge interference of the direct current power supply, the second differential mode interference elimination module is used for eliminating differential mode static electricity interference, and the first common mode interference elimination module is used for eliminating common mode surge and electrical fast transient pulse train interference. And the third differential mode interference elimination module is used for eliminating differential mode surge and electrical fast transient burst interference. According to the scheme, the protection performance of the voiceprint sensor can be improved.