37results about How to "Eliminate high frequency interference" patented technology

A single chip integrated circuit measuring circuit (1) for determining a characteristic of the impedance of an external complex impedance circuit (2) for facilitating characterization of the impedance of the complex impedance circuit (2) comprises a signal generating circuit (7) for generating a variable frequency stimulus signal for applying to the complex impedance circuit (2). A first receiving circuit (10) receives a response signal from the complex impedance circuit (2) in response to the stimulus signal and conditions the response signal. A first analog-to-digital converter (68) converts the conditioned response signal to a first digital output signal, which is read from the first analog-to-digital converter (68) through a first digital output port (14). The response signal from the complex impedance circuit (2) is a current signal, and a current to voltage converter circuit (64) converts the response signal to a voltage signal. A first RMS to DC level converting circuit (70) converts the AC voltage of the response signal to a DC voltage level, and a fourth multiplexer (67) selectively applies the voltage response signal or the DC voltage level signal to the first analog-to-digital converter (68), depending on whether it is desired that the first digital output signal should be indicative of the phase shift or amplitude change in the response signal relative to the stimulus signal. A second receiving circuit (20) receives the stimulus signal, and similarly converts the stimulus signal to a second digital output signal for facilitating comparison of the response signal with the stimulus signal.

A hybrid capacitor is provided which includes a substrate, at least one plate capacitor and at least one through hole capacitor. The substrate has through holes and the plate capacitors are on the substrate. At least one through hole capacitor and at least one plate capacitor are in parallel. The through hole capacitor at least includes an anode layer, a first dielectric layer, a first cathode layer and a second cathode layer. The anode layer is disposed on an inner surface of at least one through hole, and a surface of the anode layer is a porous structure. The first dielectric layer is disposed on the porous structure of the anode layer and covered with the first cathode layer. The first cathode layer is covered with the second cathode layer. A conductivity of the second cathode layer is larger than a conductivity of the first cathode layer.

The utility model discloses a DDFS (direct digital frequency synthesis) device-based curve generator, which comprises the successively connected DDFS device, the numerical model transform and synthetic unit and the wave filter, among which the DDFS device consists of the phase accumulator unit and the phase amplitude conversion unit. The phase accumulator unit includes the phase accumulator and the register. The phase amplitude conversion unit is a CORDIC operation module. The utility model has the advantages that a complex wave pattern can be generated for the use in the test field. The wave pattern is provided with a plurality of frequencies which can be controlled via the frequency control field inputted to the phase accumulator. The CORDIC module replaces the traditional ROM look-up table so as to lower the cost of the hardware. Also, the use of the reiteration and the pipeline technique in the CORDIC algorithm accelerate the generation of the wave pattern.

The invention belongs to the technical field of servo control, and specifically discloses a structure-optimizing servo motor speed closed loop control method. A speed closed loop control system employed in the method comprises a speed controller, a torque front feed, and a current outer ring. The system is additionally provided with a speed observer, a frequency analyzer, and a low-pass filter. The speed controller is used for observing the angular speed of a servo motor in real time, and the frequency analyzer is used for detecting the maximum frequency of speed changes detected by the observer, and enables the maximum frequency to serve as the cut-off frequency which is transmitted to the low-pass filter. Through the cooperative action of the speed observer, the frequency analyzer and the low-pass filter, the method finally eliminates the interference in a speed feedback signal and the impact from a higher-order component in a current loop actual teaching mathematic model, and improves the speed output stability and the control precision of a speed loop.

The invention discloses a photovoltaic generating control system and control method for a comprehensive tunnel. The photovoltaic generating control system comprises at least one photovoltaic board, the photovoltaic board is connected with a bus through a maximum power track and control circuit, the bus is provided with a plurality of battery which are connected in parallel, and the bus is connected with a load through an inverter. The photovoltaic board is connected with a voltage detection circuit and a current detection circuit, and the voltage detection circuit and the current detection circuit are respectively connected with a controller. The maximum power track and control circuit comprises a protection circuit, a filtering circuit and a Boost converter which are connected in order, the protection circuit is connected with the photovoltaic board, and the Boost converter is connected with the bus. The invention further provides a high-efficient maximum power track and control method. The method is quick in search speed, and high in stability precision. A large step length is automatically adopted when the maximum power point is far away, the search speed can be accelerated, and a small step length is adopted when the maximum power point is close, so the power loss can be reduced.

The invention discloses a high-voltage electrified body temperature monitoring system based on a wireless transmission mode, belonging to the field of remote monitoring system. The high-voltage electrified body temperature monitoring system comprises a monitoring center, a transport network and a site plant; a monitoring device is directly installed on the monitoring point of detected high-voltage equipment and is equipotential to the detected equipment; the monitoring device and a data concentrator are communicated in the wireless mode, and the data concentrator is connected with the monitoring center via a wired transport network / GPRS; the monitoring device adopts the design of lower energy consumption, and standby current is smaller than 2 mu A; batteries are adopted to supply power to the monitoring device; and the monitoring device adopts a wireless mode to send data, thus thoroughly solving the problem of high-voltage insulation, and realizing on-line monitoring of the high voltage equipment. The high-voltage electrified body temperature monitoring system gives an alarm in various modes, can find temperature rise of the high voltage equipment in time so as to take measures immediately, thus avoiding accidents and greatly improving the safety of power grid operation.

The invention provides a power grid reactive compensation method based on ip-iq method and phase-controlled switching technology. The power grid reactive compensation method includes step S1, detecting reactive current in a power grid in real time by the ip-iq method; step S2 performing signal zero-crossing point extraction by adopting a digital filtering technology; S3, receiving a zero-crossingpoint signal through a phase controller, using switch on / off action to switch a capacitor bank to realize zero-current input and zero-voltage cutting. According to the method, reactive current of thesystem is detected by adopting the method, and the method is also applicable under the condition of system voltage distortion and asymmetry. By adopting digital filtering, high-frequency interferencecan be effectively eliminated, and the alternating-current signals collected by the system are subjected to filtering processing. Noise and temperature drift can be avoided, and the requirement for the phase characteristics of the filter can be met. The signal zero-crossing point in the power grid performs switching action, the electric energy quality and reliability of the system can be improved,the electric power system can be simplified, and the system investment is reduced.

The invention discloses a single-phase grounding fault line selection method applied to a flexible grounding system. The method comprises three steps of fault time positioning, transient characteristic signal extraction and faulty feeder discrimination, and specifically comprises the steps of 1) carrying out wavelet packet decomposition on a zero sequence voltage signal of a neutral point, and taking a time point corresponding to a modulus maximum point as the actual fault time; 2) selecting feeder zero-sequence current signals of 1 / 4 and 3 / 4 periods before and after the actual fault time, carrying out wavelet packet decomposition and reconstruction, and extracting transient characteristic waveforms; and 3) calculating a comprehensive gray T-shaped correlation coefficient of the transientcharacteristic waveform of each feeder, and comparing the comprehensive gray T-shaped correlation coefficient with a threshold value to determine a faulty feeder. According to the method, the relevance of the dynamic change trend of the overhead line and the dynamic change trend of the cable is effectively reflected, the misjudgment caused by the difference between the capacitance values of the cable and the overhead line to the ground is reduced, the requirements of a flexible grounding system for the rapidity and accuracy of line selection are met, and the method has feasibility and practical value.

The invention discloses electrically driven equipment with control function of a brushless direct current motor. The electrically driven equipment comprises the brushless direct current motor, a power wire and an input control signal socket, and is characterized in that: a motor stator component, a motor rotor component, a controller power output component, a main control board, a motor front end cover, a motor rear end cover, a motor position sensor signal wire, a connecting cable, a motor input phase wire and a rear cover board are arranged in a shell component of the brushless direct current motor, wherein the motor stator component is arranged in the shell component in a press fit method; the motor rotor component is arranged on the motor front end cover and the motor rear end cover through a bearing; the controller power output component and the main control board are arranged on the motor rear end cover; the power wire is arranged on the main control board through the rear cover board; and the input control signal socket is arranged on the rear cover board. The electrically driven equipment of the brushless motor has a simple structure, small volume, small electromagnetic interference and low cost, is convenient to use and reliable to control.

The invention discloses a high frequency interference-elimination type water level pre-warning system based on internet of things technology, which is characterized by including a single chip microcomputer, a modulus conversion chip and a signal processing unit which are connected to the single chip microcomputer respectively, a water level sensor which is connected to the modulus conversion chip, a wireless transmission unit which is connected to the signal processing unit and an upper computer which is connected to the wireless transmission unit through a wireless network. The high frequency interference-elimination type water level pre-warning system based on internet of things technology can process monitoring signals very well, thus making the monitoring signals received by the upper computer more stable, allowing workers to analyze river water levels more easily and accurately according to the monitoring signals, and improving the warning effect greatly.

A single chip integrated circuit measuring circuit (1) for determining a characteristic of the impedance of an external complex impedance circuit (2) for facilitating characterization of the impedance of the complex impedance circuit (2) comprises a signal generating circuit (7) for generating a variable frequency stimulus signal for applying to the complex impedance circuit (2). A first receiving circuit (10) receives a response signal from the complex impedance circuit (2) in response to the stimulus signal and conditions the response signal. A first analog-to-digital converter (68) converts the conditioned response signal to a first digital output signal, which is read from the first analog-to-digital converter (68) through a first digital output port (14). The response signal from the complex impedance circuit (2) is a current signal, and a current to voltage converter circuit (64) converts the response signal to a voltage signal. A first RMS to DC level converting circuit (70) converts the AC voltage of the response signal to a DC voltage level, and a fourth multiplexer (67) selectively applies the voltage response signal or the DC voltage level signal to the first analog-to-digital converter (68), depending on whether it is desired that the first digital output signal should be indicative of the phase shift or amplitude change in the response signal relative to the stimulus signal. A second receiving circuit (20) receives the stimulus signal, and similarly converts the stimulus signal to a second digital output signal for facilitating comparison of the response signal with the stimulus signal.

The invention is mainly used to detect short trouble of a power line. The judging conditions mainly include: 1, a power line works normally; 2, current is over k times of the maximum load current in 24 hours; 3, fault current at least keeps 40 minutes, and the change of current amplitude values is larger than omega during the period of time; and 4, a transformer substation is tripped, and the power line is powered off. The invention mainly solves the problems of the self detection of the short trouble and unwanted operations caused by preventing reverse electric transmission of the power line existing in the distribution network, is applicable to various circuits, does not need to set a fixed value of the short circuit current and has the function of adaptability.

This invention relates to a transistor AC power supply purification circuit, in which, a large power rectifying bridge divides a 50Hz AC circuit into positive and negative two half-laps for shaping, the rectification of their waveform is composed of first to fourth level diodes and a capacitor rectification network circuit including two serial diodes in parallel connection with opposite polarity for processing rising and trailing edge voltages separately, each diode is parallel to a capacitor to make up of first level calibration circuit, which gets a positive half-lap of a sine wave from both ends of a large capacitor to be sampled and amplified by a triode to enter into a current or power amplifying level, the output of which is connected with the calibration circuit the waveforms of the positive and negative half-laps are shaped and calibrated and than are composed to a sine wave by a large power rectification bridge.

A scanning optical monitoring system and method are appropriate for high speed scanning of a WDM signal band. The system and method are able to identify dropped channels or, more generally, discrepancies between the determined or detected channel inventory and a perpetual inventory for the WDM signal, which perpetual inventory specifies the channels that should be present in the WDM signal assuming proper operation of the network. The system includes a tunable optical filter that scans a pass band across a signal band of a WDM signal to generate a filtered signal. A photodetector then generates an electrical signal in response to this filtered signal. A decision circuit compares the electrical signal to a threshold and a controller, which is responsive to the decision circuit, inventories the channels in the WDM signal.

The invention provides a differential charge amplifier with high precision, low temperature drift and low offset, the differential charge amplifier has the advantages of high amplification precision on charge signals, small temperature drift and low offset voltage, and can be used for accurately amplifying vibration charge signals. The amplifier structurally comprises an overload protection circuit, a differential charge conversion circuit, a low-pass filter circuit and a high-pass filter circuit, which are connected in sequence, and a power supply conversion circuit used for supplying power to the circuits, wherein the differential charge conversion circuit comprises a first inverting amplifying circuit, a second inverting amplifying circuit and a subtraction operation circuit; a Qp anode and a cathode of a charge signal are respectively connected to the first inverting amplifying circuit and the second inverting amplifying circuit through capacitors, and the feedback resistance branches of the two inverting amplifying circuits respectively form T-shaped networks with the same RC series branch; the outputs of the first inverting amplifying circuit and the second inverting amplifying circuit serving as a positive phase input and a negative phase input are respectively connected to the subtraction operation circuit.

This invention relates to a digital anti-interference circuit with fixed frequency including: a phase reverser used in reversing waveforms, the input of which is connected with a primary square V1 generating triangle carrier signals, the output signal V3 is sent to an input pin of a double-input exclusive-OR gate and V1 is connected to the input end of a two-D trigger, an exclusive-OR gate used in comparing the input end through th reversed primary square V3 and PWM control signal Vin with burrs, the output signal V2 is sent to the CLK of the two-D trigger, a double D trigger for shaping the burr PWM control signals so as to output smooth waveforms Vo.

The invention provides a pump bearing fault diagnosis method, which comprises the following steps of: obtaining a vibration signal through a signal detection module, and eliminating high-frequency interference through a conditioning circuit; normalizing the obtained data, decomposing the fault signal of the pump unit by adopting an inherent time scale decomposition method, obtaining a baseline signal and an inherent rotation component by one-time decomposition, and extracting RMS of a plurality of inherent rotation components as characteristic values to form a fault characteristic data set under the rotation frequency; repeating the operation under different faults of the bearing to obtain a fault sample data set X; taking the data set X as the input of LIB-SVM, and constructing a fault classification model to carry out the mode recognition of a bearing fault signal; establishing a bearing fault database. The method for analyzing the current and voltage signals of the motor has the advantages of being convenient to operate, flexible to install and good in stability.

The invention discloses a composite high-frequency substrate with the characteristics of high Dk and low Df. The high-frequency substrate comprises a first copper foil layer and a core layer; the corelayer comprises a plurality of high-molecular polymer film layers and a plurality of dielectric adhesive layers; the dielectric adhesive layer comprises at least one of a first dielectric adhesive layer and a second dielectric adhesive layer; the first dielectric adhesive layer is an adhesive layer with a Dk value of 6-30 and a Df value of 0.002-0.020, the second dielectric adhesive layer is an adhesive layer with a Dk value of 15-100 and a Df value of 0.002-0.020, and the Dk value of the second dielectric adhesive layer is greater than the Dk value of the first dielectric adhesive layer; andthe core layer refers to a core layer with a Dk value of 6-50 and a Df value of 0.002-0.020. The laser drilling technology is better, the inward shrinkage condition is not likely to happen, the hygroscopicity is low, the insulativity is high, the size stability is high, the thermal stability is excellent, and the high Dk and low Df electrical property is better; normal press fit parameters can beused for being matched with quick press equipment or pressure transmission equipment, the cost advantage is achieved, and the thick film manufacturing technology is achieved.

The invention discloses an intelligent piezoelectric vibration temperature composite sensor based on network serial communication. The composite sensor comprises a sensor shell, two 8PIN connectors, a main control circuit board assembly, a shielding structure assembly, a vibration sensor assembly, and a temperature sensor assembly. The vibration sensor assembly and the temperature sensor assembly are respectively provided with a digital output module with a Butterworth intelligent low-pass filter. According to the invention, single-line wiring can be realized, wiring is simple, and cables are convenient to install and distinguish; and moreover, the wiring space is small, independent wiring is facilitated, the shielding structure assembly can reduce an external equipment noise and interference of an electromagnetic field, and the Butterworth intelligent low-pass filter can remove high-frequency interference, reduce the noise and prevent high-frequency interference, caused by influence of other circuits or equipment, on output signals of the sensor. Therefore, the accuracy of the sensor is improved.

The invention provides a signal processing circuit and belongs to the field of display. The signal processing circuit comprises a filtering unit, wherein the filtering unit is connected with a touch integrated circuit and a touch electrode in a touch display device; the filtering unit is used for acquiring a first scanning signal which is emitted by the touch integrated circuit and is to be sent to the touch electrode; filtering the first scanning signal to obtain a second scanning signal and sending the second scanning signal to the touch electrode, wherein the frequency range of the second scanning signal is located in a preset frequency range of zero Hz-1 MHz. The problem of lower accuracy of the touch display device for judging the touch position is solved. The signal processing circuit is used for processing signals.

The invention relates to a filtering phase discriminator type dynamic interferometry system, which is composed of an interference optical system, a photoelectric detector and a filtering phase discriminator system for performing optical interference measurement on the object to be detected. The optical interference system comprises light paths and a phase shifting device, and the filtering phase discriminator system is composed of a synchronic phase shift control circuit and a signal processing circuit. The measurement system provided by the invention can perform on-line measurement in severeenvironment, can obtain the measurement result only needing an interference graph, does not lower CCD resolution ratio and has no special requirement on measurement environment, and has the characteristics of strong interference resistance, high measurement precision, high signal noise ratio, high resolution ratio, short measurement time and the like.

The invention relates to a small-size watermelon ripeness detection method based on a dielectric frequency spectrum. The small-size watermelon ripeness detection method comprises the following steps of: placing a watermelon to be detected into a detection device formed by three sets of electrodes which are tightly stuck to the surface of the watermelon; applying alternating electromotive force among the electrodes; measuring a dielectric response signal of the watermelon to the alternating electromotive force; carrying out data processing on a dielectric frequency spectrum signal; judging the ripeness of the watermelon through a clustering analysis; meanwhile, collecting temperature information in the detecting process and carrying out temperature compensation in the data analyzing process. According to the method disclosed by the invention, dielectric spectrums with different frequencies are used for realizing the nondestructive detection, and the problem that the measurement is inaccurate, caused by only using a single frequency, is overcome; meanwhile, the dielectric spectrum scanning is carried out at a plurality of angles so that the measuring error caused by individual difference is reduced; the electromagnetic interference is eliminated and the high-frequency interference to a collection circuit by an exciting circuit is eliminated; a temperature compensation algorithm is added and the influence on the measurement accuracy by temperature variation is eliminated.

The polarization / depolarization current test method and test device of multilayer oil-paper composite insulation structure under high voltage level are used for the research on polarization / depolarization current characteristics of multilayer oil-paper composite insulation under high voltage level. In the oil-paper insulation polarization / depolarization current test, the space charge dissipation time is long, and the data processing process is subject to high-frequency interference. Test methods: 1. Assembly of the test device; 2. Apply DC high voltage to the three-electrode system to test the polarization current of the multi-layer oil-paper composite insulating structure, and then remove the DC high voltage to test the depolarization current of the multi-layer oil-paper composite insulating structure; 3. Heat the transformer oil in the test tank; 4. Use the method of piecewise linearization with unequal time intervals to process the polarization current and depolarization current obtained in step 2 respectively. The invention adopts the method of unequal time interval piecewise linearization to count the test data, which can well eliminate the high frequency interference in the test process.

The invention provides a control method and device for a deep-energy-level transient spectrum trigger signal, and a storage medium, and relates to the technical field of testing. The method comprisesthe following steps: determining trigger signal curve data according to a preset duration, wherein the trigger signal curve data comprise a zero-voltage data segment, a transition curve data segment and a maintaining amplitude data segment, and the transition curve data segment forms a smooth rising edge curve or a falling edge curve and is used for achieving smooth transition between the zero-voltage data segment and the maintaining amplitude data segment; converting the trigger signal curve data into an analog signal; modulating the analog signal to form an injection voltage signal so as toinject the injection voltage signal into a tested device. A zero-voltage injection form is adopted, so that an injection pulse signal forms a rising edge and a falling edge of the signal in a zero-voltage edge piecewise exponential function waveform form, a sharp edge of the waveform is eliminated, and transient change high-frequency distortion of the waveform is eliminated, thereby ensuring the transient of triggering and reducing the interference of the system.

The invention discloses a rail height irregularity measurement method based on a single-axis gyroscope. The method includes the steps: firstly, installing a single-axis gyroscope; secondly, acquiringthe angular speed outputted by the single-axis gyroscope; thirdly, processing the angular speed outputted by the single-axis gyroscope; fourthly, acquiring rail irregularity data. The method is simplein step, reasonable in design, low in implementation difficulty and high in practicability, only needs the single-axis gyroscope and a speedometer and can be widely applied to measurement of variousrails, and measurement accuracy is ensured through zero point correction and filtering.

The invention discloses a high-voltage electrified body temperature monitoring system based on a wireless transmission mode, belonging to the field of remote monitoring system. The high-voltage electrified body temperature monitoring system comprises a monitoring center, a transport network and a site plant; a monitoring device is directly installed on the monitoring point of detected high-voltage equipment and is equipotential to the detected equipment; the monitoring device and a data concentrator are communicated in the wireless mode, and the data concentrator is connected with the monitoring center via a wired transport network / GPRS; the monitoring device adopts the design of lower energy consumption, and standby current is smaller than 2 mu A; batteries are adopted to supply power to the monitoring device; and the monitoring device adopts a wireless mode to send data, thus thoroughly solving the problem of high-voltage insulation, and realizing on-line monitoring of the high voltage equipment. The high-voltage electrified body temperature monitoring system gives an alarm in various modes, can find temperature rise of the high voltage equipment in time so as to take measures immediately, thus avoiding accidents and greatly improving the safety of power grid operation.

For settling a problem of homogenizing VISAR probe light illumination, the invention provides a probe light homogenizing system of a random reflection surface speed interferometer. The probe light homogenizing system comprises fiber output laser, a collimating lens and a beam compressing mirror. The collimating lens is arranged in the output optical path of the fiber output laser. Furthermore the focal plane of the collimating lens is arranged at the optical fiber end surface of the fiber output laser. The beam compressing mirror comprises a beam compressing mirror front set and a beam compressing mirror back set. The beam compressing mirror front set is arranged in an output optical path of the collimating lens. The beam compressing mirror back set is arranged in an output optical path of the beam compressing mirror front set. Furthermore the focal plane of the beam compressing mirror front set is superposed with the focal plane of the beam compressing mirror back set, thereby forming a Kepler telescope structure. The fiber core diameter D0 of the fiber end surface, the focal length f1 of the collimating lens, the focal length f2 of the beam compressing mirror front set, and the focal length f3 of the beam compressing mirror back set satisfy a relationship which is shown in the description, wherein alpha is an emergent half-angle of the emergent light beam of the fiber end surface, and furthermore f2>f1>5mm.

The invention discloses a composite type capacitor comprising a substrate, at least a parallel-plate capacitor and at least a through-hole capacitor. The substrate is provided with through holes, and the parallel-plate capacitor is positioned on the substrate and comprises a first conductor layer, two dielectric layers and a second conductor layer. The at least one through-hole capacitor is connected with the at least one parallel-plate capacitor in parallel. The through-hole capacitor at least comprises an anode layer electrically connected to one face of the substrate with the first conductor layer, a first dielectric layer, a first cathode layer and a second cathode layer electrically connected to the other face of the substrate with the second conductor layer, and single poles of the parallel-plate capacitor and the through-hole capacitor are pulled out of the surface of the substrate. The anode layer is positioned on the inner surface of at least one through hole, and the surface of the anode layer is a multihole structure. The first dielectric layer is positioned on the multihole structure of the anode layer. The first cathode layer is covered on the surface of the first dielectric layer, and the second cathode layer is covered on the surface of the first cathode layer.