42results about How to "Fast sampling rate" patented technology

The invention relates to a data acquisition unit for on-line detection of transformer partial discharge and a detection method thereof. The data acquisition unit detects and acquires the transformer partial discharge signals and transmits the signals to a host computer for processing via a transformer partial discharge signal amplification module, a high speed data acquisition module and a remote communication module. In the invention, proper program control filtering and amplifying circuit are designed and manufactured, the precision of signals is high, the design and manufacturing of a high-speed and large-capacity multiple-channel synchronous data acquisition module circuit are finished, the requirement of detecting external multi-channel circuits can be met, and the adaptability is good; the invention is characterized by rapid sampling rate and large storage capacity, etc.; the whole acquisition system can be divided into a plurality of channels, the maximum sampling rate of each channel can reach 20MHz and the maximum storage depth can reach 512 K words; the data acquisition unit finishes digitization of partial discharge signals and upload the signals for processing, thus effectively reducing the distortion and aberration of the partial discharge signals during transmission, meanwhile, the data is transmitted by adopting the GPRS wireless communication technology, which reduces the cost and facilitates the construction and installation.

A system and methods for high-speed functional magnetic resonance imaging using multi-slab echo-volumar imaging (EVI), specifically a combination of multi-slab excitation and single-shot 3D encoding with parallel imaging to reduce geometrical image distortion and blurring, and to increase blood oxygenation level-dependent (BOLD) sensitivity compared to conventional echo-planar imaging (EPI).

The subject invention discloses devices and methods for sampling an analog signal in order to perform data analysis. More particularly, the subject invention provides a time-resolved, direct, high-speed sampling of analog output of a detector, in order to capture harmonic content of the signal without the need to modulate the detection system. The sampling devices and corresponding methods include a detector module for measuring a response generated from a sample, an analog to digital converter for sampling the analog signal, received from the detector module, and converting it into a digital signal; and a logic circuit coupled to the converter for processing the digital signal. The sampling rate of the converter is faster than the response of the sample, and the logic circuit is capable of analyzing the digital signal acquired from the converter and continuously transferring the data analysis obtained to a storage or display device.

In one set of embodiments, a circuit may be implemented to deliver accurately ratioed currents to a remotely located semiconductor device that has a substantially non-linear input-output characteristic that varies with temperature and is subject to effects of electromagnetic interference (EMI). The circuit may be configured to use common mode rejection by establishing an identical impedance at each of the two terminals of the remotely located semiconductor device, in lieu of coupling shunting capacitor(s) across the terminals, in order to reject EMI signals while performing temperature measurements using the remotely located semiconductor device. This may facilitate maintaining fast sampling times when performing temperature measurements, while providing a more effective method for handling EMI induced currents that may lead to temperature measurement errors, thereby eliminating those errors.

A delay unit comprises a plurality of taps for sequentially delaying an input digital received signal. A shift unit changes combinations of a plurality of digital received signals delayed by the delay unit and a multiplier unit. A coefficient retaining unit manages a plurality of coefficients to be multiplied by the plurality of digital received signals delayed by the delay unit. A selector unit 352 selects one of the coefficients retained in the coefficient retaining unit in accordance with an instruction from a control unit. The multiplier unit multiplies the plurality of digital received signals delayed by the delay unit by the coefficient selected by the selector unit. An adder adds up results of multiplication by the multiplier unit and outputs a result of addition as a filter output signal.

The invention provides a high-speed seamless capture pulse power statistics measuring method. The method comprises: in a demodulation and front-end processing unit N1, performing demodulation on microwave signals to obtain envelope signals of the microwave signals, after logarithmic amplification and linear conditioning are performed on the envelope signals after demodulation, adjusting demodulation voltages to the input scope of an A/D converter N2, the N2 being a 14-digit A/D converter with a rate of 100 Ms/s, converting the demodulation voltages into ADC data, and sending the ADC data into an FPGA N3. By using the scheme, the sampling rate can be as fast as 10 Ms/s so that modulation signals with pulse widths greater than 100 ns are not missed, and the statistics measuring demands of pulse power such as radar, guidance, wireless communication and the like can be basically satisfied.

The invention relates to a voice recorder and relative voice coder/decoder, wherein it comprises multiplexer, sequential analogue/digit converter, and pulse modulation digit circuit; the multiplexer via the first clock signal alternatively output left and right channel input signals; the converter is connected to the multiplexer, while its operation frequency is second clock signal, to convert the left and right channel input signals into digit signals; the pulse modulation digit circuit converts the output signal of converter from serial digit code into parallel digit code.

A high-speed optical quantizer based on a non-linear harmonic property of a high-speed modulation light transmitting device comprises a high-speed microwave electric signal source, a sampling light source receiving signals of the high-speed microwave electric signal source, a strength modulator, a high-speed photoelectric probe, a to-be-tested simulation microwave signal source sending signals to the strength modulator, a linear electric amplifier receiving signals of high-speed photoelectric probe, a high-speed modulation light transmitting device receiving signals of the linear electric amplifier, a wave guide array optical grating and a parallel high-speed light probe array, wherein the output end of the strength modulator is connected with the output end of the sampling light source, the input end of the high-speed photoelectric probe is connected with the output end of the strength modulator, the input end of the wave guide array optical grating is connected with the output end of the output end of the high-speed modulation light transmitting device, and the input end of the high-speed light probe array is connected with the output end of the wave guide array optical grating.

The invention relates to a monitoring method. The invention provides a water and soil conservation monitoring method based on a three-dimensional image reconstruction and analysis technology. The method comprises the steps that: firstly, a system periodically obtains a plurality of initial images from different angles of one region to be detected; the system carries out registering on the plurality of initial images; the system carries out image point cloud data extraction on the registered images; then the system generates a TIN triangulation network according to the image point cloud data and further realizes the three-dimensional model reconstruction of the region to be detected, and a three-dimensional model of the region to be detected is generated; and finally, the system carries out length, area and size quantified calculation on a relative position, compares the calculated values with corresponding values of the previous cycle and analyzes the consistence of water and soil conservation. The application of the three-dimensional image reconstruction and analysis technology fills the gap of quantitative monitoring content irregular monitoring methods and means in the water and soil conservation monitoring work, and the automatic degree of the field monitoring work is improved. The monitoring method is applicable to water and soil conservation.

The invention discloses a power quality monitoring device for power distribution network based on a data acquisition card, which comprises a power supply circuit, a voltage and electric current acquisition circuit, a synchronous phase-lock circuit, a signal conditioning circuit, a filter circuit, a programmable control amplifying circuit, a frequency measurement circuit, a data acquisition card and a computer, wherein the voltage and electric current acquisition circuit, the synchronous phase-lock circuit, the signal conditioning circuit and the filter circuit are connected in sequence; the filter circuit is connected with the programmable control amplifying circuit and the frequency measurement circuit respectively; the programmable control amplifying circuit and the frequency measurement circuit are connected with the data acquisition card; the data acquisition card is connected with the computer; and the circuits are also connected with the power supply circuit respectively. Through the adoption of the high-precision multi-channel data acquisition card, the power quality monitoring device, provided by the invention, has the advantages that simultaneous sampling by multiple channels can be realized; the data sampling precision is high; the conversion precision reaches 14 bits; the sampling speed is high; and the highest sampling velocity can reach 2.5 us.

The scanner is composed of scanning head and control circuit. The character is that DSP digital signal processor is utilized. The storage unit includes DSP supplied 18 bits address line and 16 bits data line connected to 18 bits address line and 16 bits data line of flash memory Am29F400B. Buffer 74HC244 reshapes electrical level of signal unit of the scanning head. Serial CCD image signal of reshaped output is sent to BDR0 multichannel-buffered serial receiving pins. DSP converts the said serial signal to 16 bits parallel signal, which is received in DMA mode and temporary stored in RAM. Finally, data in the RAM are sent to data bus D0-D15. The invented scanner can complete scanning operation independently without computer, and features high adaptability, and high quality.

The invention discloses a traveling wave protection acquisition circuit which comprises a current transformer, a precision operational amplifier follower circuit, a precision operational amplifier reverse proportional attenuator circuit, a single-end bipolar-to-unipolar differential circuit, a single-channel unipolar differential high-precision AD acquisition circuit, and is characterized in thatthe output end of the current transformer is connected with the positive input end of the precision operational amplifier follower circuit; the output end of the precision operational amplifier follower circuit is connected with the input end of the single-end bipolar-to-unipolar differential circuit; the output end of the single-end bipolar-to-unipolar differential circuit is connected with the input end of the single-channel unipolar differential high-precision AD acquisition circuit; and the output end of the precision operational amplifier reverse proportional attenuator circuit is connected with the single-end bipolar-to-unipolar differential circuit. The traveling wave protection acquisition circuit is high in driving load capacity, high in sampling precision, high in sampling rate and suitable for traveling wave protection acquisition, and has high practical value and wide application prospects.

The invention discloses a high-speed light quantizer based on a four-wave mixing effect. The light quantizer comprises a first optical pumping source, a second optical pumping source and a sampling light source, wherein the output end of a high-speed microwave electric signal source is connected with the input end of the sampling light source; the input ends of a first optical amplifier, a secondoptical amplifier and a third optical amplifier are respectively connected with the output ends of the first optical pumping source, the second optical pumping source and the sampling light source; the input end of a strength modulator is connected with the output end of the third optical amplifier; the output end of a microwave signal source to be tested is connected with the input end of the strength modulator; the input ends of a first polarization controller, a second polarization controller and a third polarization controller are respectively connected with the output ends of the first optical amplifier, the second optical amplifier and the third optical amplifier; the input end of a first waveguide array grating is connected with the output ends of the first polarization controller,the second polarization controller and the third polarization controller respectively; the input end of a nonlinear medium is connected with the output end of the first waveguide array grating; the input end of a second waveguide array grating is connected with the output end of the nonlinear medium; and the input end of a parallel high-speed optical detection array is connected with the output end of the second waveguide array grating.

The invention discloses a laser wavelength real-time monitoring method based on a polarization optical fiber interferometer, which comprises the following steps of: acquiring four paths of interference signals with phase shifts of 0 degree, 90 degrees, 180 degrees and 270 degrees by using a polarization optical fiber interferometer system wavelength real-time monitoring device; the four paths of space phase-shifting interference signals carrying real-time wavelength information are demodulated through a four-step phase-shifting method to obtain corresponding phase information, then wavelength information is obtained, and real-time monitoring of the wavelength of the laser is achieved. A polarization maintaining optical fiber and a device are adopted in the polarization optical fiber interferometer system, synchronous phase shifting is achieved, and meanwhile the problem of amplitude jitter caused by the unstable polarization direction of interference light in a common optical fiber interferometer is solved. According to the invention, only one four-quadrant detector is needed to obtain the light intensity information of four pixels, and the wavelength variation can be fed back, so that the error problem caused by long displacement is avoided, the cost is reduced, the method has the characteristics of low insertion loss, high sampling rate and high precision, and the real-time wavelength monitoring of the laser can be realized.

The invention discloses a blockage prevention and removal control device and method based on a differential type large blast furnace injection system. According to the method, in the normal working process of the system, when pulverized coal accumulation or pulverized coal adhesion occurs in a coal conveying pipeline, friction rise exists in the coal conveying pipeline, so that phase deviation occurs to waveforms acquired by a pressure sensor at a discharge port, and meanwhile, the sine wave amplitude of the discharge port is reduced; the control device analyzes and calculates the acquired pressure data curves of a feed opening and the discharge port, calculates real parts, imaginary parts and effective values of the two curves in a phasor mode, and calculates a phase angle between the two curves according to the phasor; and when the obtained effective value and the phase angle both exceed preset threshold values, it is judged that the pipeline is blocked, and the control device controls the injection system to conduct blockage removal action. The device and the method have the characteristics of high reliability, high acquisition precision, high sampling speed, high action sensitivity, capability of pre-judging the coal conveying pipeline in advance, short blockage removal action time and the like.

The present disclosure provides a device for monitoring and visualising electrical activity of biological tissue. The device uses a sensor arrangement comprising a matrix of conductive sensors and a transducing element for transducing electric fields in a variation of an optical property. In use, electric fields generated by the biological tissue are sensed by the sensor arrangement and transduced by the transducing element for optical imaging.