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.

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.

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.

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 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.

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.