27 results about "Frequency counter" patented technology

The invention discloses a hybrid high-precision frequency weighting method and system and electronic equipment, and the method comprises the steps: obtaining an original sound signal, carrying out the analog-to-digital conversion, and carrying out the preprocessing of the sound signal after the analog-to-digital conversion, so as to obtain a signal frequency spectrum; segmenting the signal spectrum, and weighting each segment to obtain a first weighting sound level and a second weighting sound level; superposing the first weighted sound level and the second weighted sound level to determine a total weighted sound level; and performing dynamic error calibration on the total weighted sound level, determining a standard error, and when the standard error is smaller than or equal to a preset error threshold value, outputting the total weighted sound level. According to the invention, a differentiated optimization strategy is adopted, and the attenuation deviation of a traditional digital filter in a low-frequency area is effectively corrected in a low-frequency band; in the middle and high frequency bands, the accuracy is ensured, meanwhile, the occupation of operation resources is remarkably reduced, the signal processing delay time is shortened, and the response requirement of real-time noise monitoring can be met.

The method comprises: obtaining a sending parameter of a sending data packet set by a user; simulating a sending device in a network to send data packets based on the sending parameter, and outputting a level signal to a frequency counter after sending a set number of data packets, and the current output level signal and the last output level signal are opposite in polarity; obtaining a data sending frequency parameter from the frequency counter after sending a total number of data packets; increasing an initial packet frequency in the sending parameter according to a set rule, and returning to the step of simulating the sending device in the network to send data packets based on the sending parameter; decreasing an initial packet length in the sending parameter according to a set rule, and restoring the packet frequency in the sending parameter to the initial packet frequency, and returning to the step of simulating the sending device in the network to send data packets based on the sending parameter.

The application discloses a Bluetooth channel sounding high-precision ranging SOC method, a chip and equipment. The method comprises the following steps: controlling a radio frequency transceiver front end to output a data frame and a received signal strength quantization value, a direct memory access controller carries the data frame to a memory of a channel sounding coprocessor, the coprocessor compares the quantization value with a multipath deep fading threshold value, and when the quantization value is lower than the threshold value, corresponding data is overwritten as a digital zero, a polar coordinate system conversion forms a frequency domain channel response array, an inverse fast Fourier transform is performed to extract a line-of-sight path main peak and calculate a first distance value, a high-frequency counter records a physical round trip time and converts a second distance value, a hardware interlocking comparator calculates a difference value, and when the difference value exceeds a safety tolerance window, a blocking instruction is sent to the direct memory access controller. The application can solve the data distortion problem in a multipath environment and eliminate the delay vulnerability of the anti-relay attack of the physical layer.

The application discloses a kind of laser remote frequency stabilization device based on shared variable, it is related to laser frequency stabilization technical field.The structure of the present application is: laser (1), optical fiber (2) is connected before and after, optical fiber (2) and frequency reference light (3) are connected with laser beam combiner (4) respectively, laser beam combiner (4), electric detector (5), frequency counter (6), data publishing end (7), network (8), data receiving end (9) and laser (1) are sequentially connected.Compared with the similar frequency stabilization device of prior art, the present application can realize long-distance laser frequency stabilization, and has good transmission performance, low cost, high scalability, and can be widely used in laser frequency stabilization technical field.

Medical diagnostic devices and related methods of use are described in which a sensor coil may be connected with a resistive, inductive, and capacitive (RCL) circuit including a power meter and a frequency counter, and the sensor may be positioned on a chest of a subject. The sensor apparatus may apply an alternating current through the sensor coil. The sensor apparatus may measure parallel resistance values in the sensor coil using the power meter for a time interval while the subject inhales and exhales. The sensor apparatus may record the parallel resistance values. The sensor apparatus may determine a first change in the parallel resistance values by measuring a difference between a crest and a trough of the parallel resistance values, wherein the crest of the parallel resistance value corresponds to the inhale and the trough of the parallel resistance value corresponds to the exhale of the subject's breath.

The invention provides a quantum frequency angle gauge based on Littrow type grating frequency selection, which comprises a laser generating device, a first half-wave plate (9), a polarization splitting prism (11), a photoelectric detector (12) and a frequency counter (13), a horizontal rotating table (3) is arranged on a light path between the laser generating device and the first half-wave plate (9), a plane mirror (5) and a diffraction grating (6) are arranged on the horizontal rotating table (3) in parallel, and the diffraction grating (6) is arranged on the plane mirror (5). A second half-wave plate (10) and an optical frequency comb (8) are arranged on the other light path of the polarization splitting prism (11); and when the horizontal rotating table (3) rotates to cause the frequency change of the measured laser, the variable quantity of the beat frequency is equal to that of the measured laser. According to the quantum frequency angle gauge based on Littrow type grating frequency selection, the angle measurement resolution limit of the quantum frequency angle gauge reaches 0.00001 ''magnitude, and the application requirements of various kinds of ultra-precise angle measurement can be met.

The invention discloses a movable E-15 magnitude ultra-stable laser comparison test system, which relates to the technical field of optical metrology and comprises a PDH laser frequency stabilization unit, a beat frequency unit, matched test equipment and a computer. An output optical signal of a to-be-tested PDH system is directly connected to a beat frequency module in a cabinet, beat frequency is carried out on the output optical signal and original PDH laser of the cabinet in the beat frequency module, a radio frequency signal obtained after beat frequency can be respectively accessed to a frequency counter and a frequency spectrograph, and a signal processed by the frequency counter and the frequency spectrograph can be accessed to a computer. And finally, indexes such as frequency stability and line width can be directly read through a software control end of a computer.

The invention discloses a sensor overturn compensation method, system and device based on range prediction, and a storage medium. The method comprises the following steps: configuring a range upper limit threshold and an upper / lower limit threshold according to a sensor model; receiving a data message containing an accumulated value, a message ID and a timestamp; performing repeated judgment by comparing the message ID with the timestamp; if the message is not repeated, performing smooth filtering on the accumulated value, then performing trend analysis in combination with sliding window statistics, and when a transition mode from a continuous high order to a continuous low order is detected, judging overturning; updating a turnover frequency counter of the sensor, and calculating a real accumulated value after compensation according to the turnover frequency, the upper limit of the measuring range and the current accumulated value; and finally updating the cache state. According to the invention, automatic and accurate detection and real-time compensation of data overturning of the accumulation type instrument are realized, and the automation level, accuracy and reliability of data processing are effectively improved.

A semiconductor device includes: an oscillator circuit including a plurality of logic gate groups connected in series; a frequency counter measuring an oscillation frequency of the oscillator circuit; and a comparator comparing a reference value and the oscillation frequency of the oscillator circuit measured by the frequency counter. Each of the logic gate groups includes first to third logic gates each made of a transistor and connected in series. A first fan-out number of the first logic gate is larger than a second fan-out number of the second logic gate and the third logic gate. The first to third logic gates have the same driving force from one another.

The embodiment of the invention provides a crystal oscillator single event effect test system. In one specific embodiment, the system comprises a vacuum target chamber, a digital power supply, a digital switch controller, a test terminal and a frequency counter, the vacuum target chamber provides a vacuum environment for the plurality of crystal oscillators to be tested; a particle beam line is arranged in the vacuum target chamber; the test terminal controls gating of the digital switch controller, so that the digital power supply supplies power to the gated crystal oscillator to be tested through the digital switch controller, and the frequency counter collects the output frequency of the gated crystal oscillator to be tested; and the test terminal is also used for controlling the particle beam line to radiate the plurality of crystal oscillators to be tested respectively, acquiring the output current acquired by the digital power supply and the output frequency acquired by the frequency counter, and identifying and recording a single event upset event and a single event locking event of the gated crystal oscillators to be tested according to the output current and the output frequency.

The invention provides a batch test device for crystal oscillators, and the device comprises a vacuum tank body which is used for providing a crystal oscillator test environment; the crystal oscillator batch test plate is positioned in the vacuum tank body and is used for bearing and fixing a plurality of crystal oscillator samples to be tested; the stabilized voltage supply and the frequency counter are positioned outside the vacuum tank body; a power adapter and a signal adapter are arranged on the vacuum tank body; the crystal oscillator batch test board is connected with a power line and a signal line which are used for being electrically connected with a to-be-tested crystal oscillator sample. The power line is led out of the vacuum tank body through the power adapter, and the signal line is electrically connected with the signal adapter; the voltage-stabilized power supply is led out of one end outside the vacuum tank body through a connecting power line to supply power to a crystal oscillator sample to be tested on the crystal oscillator batch test board; and the frequency counter is connected with the signal conversion head so as to acquire an output frequency signal of a crystal oscillator sample to be tested on the crystal oscillator batch test board. The testing device can save the testing time, reduce the opening times of the vacuum tank body and improve the testing efficiency.

The embodiment of the application discloses a flow probe high-precision time detection system, method, equipment and medium, the system comprises: a flow probe, a first frequency counter, a second frequency counter and a B code signal source, wherein: the B code signal output end of the B code signal source is connected with the B code signal input end of the flow probe; the 1PPS signal output end of the B code signal source and the 1PPS signal output end of the flow probe are connected to channel A and channel B of the first frequency counter respectively; and the 1MHz signal output end of the B code signal source and the 1MHz signal output end of the flow probe are connected to channel A and channel B of the second frequency counter respectively.

1. Name of the product in this design: Frequency Counter. 2. Purpose of this design: An instrument for measuring and displaying frequency parameters. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: 3D view 1. 5. Other situations requiring explanation: Section A is the display screen.

A method for learned image compression implemented in an autoencoder includes: a) extracting from an image a latent space by the learnable encoder; b) quantizing the latent space by a quantizer to obtain a quantized latent space; c) entropy coding the quantized latent space by an entropy encoder to obtain a bitstream, wherein an entropy model used to encode the latent space is represented by a probability distribution; d) entropy decoding the bitstream by an entropy decoder to obtain an entropy decoded bitstream; e) feeding the entropy decoded bitstream to the decoder; f) recover a reconstructed image by the decoder; g) training the autoencoder via standard gradient descent of the backpropagated error gradient by finding learnable parameters of the learnable encoder and of the decoder that minimize a rate distortion cost function, wherein the entropy encoder is based on a differentiable formulation of a soft frequency counter.

Provided is a development support device capable of obtaining a total number of steps of a load, a required time when a program is executed is predicted. The development support device of the embodiment is a development support device that supports development of a program including a function block. The development support device of the embodiment includes a step counter that counts a number of execution steps of the function block indicating a number of processes executed in the function block, a frequency counter that counts a number of times of use of the function block used in the program, and an arithmetic unit that calculates a product of the number of times of use of the function block and the number of execution steps of the function block, and outputs the number of execution steps of the function block in the program.

The invention provides a digital high-voltage power supply suitable for an electric propulsion system. The digital high-voltage power supply comprises an FPGA, a high-voltage power supply, a phase-shifted full-bridge power module, a feedback measurement module and an A / D sampling module, wherein the FPGA adopts two frequency counters to realize the control of four switch tubes; determining a control time sequence of a leading arm and a lagging arm according to the MOS turn-on holding time T1, the switching tube driving period T, the dead time t and the phase shift time delta; and starting a corresponding frequency counter cnt1 when the leading arm is set and conducted, starting a frequency counter cnt2 when the phase shifting time is reached, immediately starting a lagging arm, and then setting or zeroing corresponding switch tube driving signal waveform control when the counts of the cnt1 and the cnt2 reach corresponding count values according to a control time sequence. The control time sequence is realized based on the cooperation of the two counters, the digital-based high-voltage power supply control is realized on the basis of using fewer FPGA resources, the stability is good, and the reliability is high.

The application discloses an underwater distance measurement system and method based on tunable chirped pulse interference, and a tunable optical frequency comb generates an optical frequency comb pulse signal with a variable repetition frequency, which is transmitted through a monitoring light path, a reference light path and a measurement light path respectively, the monitoring light path uses a photodetector and a frequency counter to monitor the repetition frequency of the optical frequency comb pulse signal in real time; a long optical fiber is used as a reference arm in the reference light path to generate a reference pulse signal; a long optical fiber stabilization unit is further arranged in the reference light path; the measurement light path generates a measurement chirped pulse signal; the reference light path and the measurement light path interfere to generate an interference signal, high-resolution spectral image high-speed acquisition of a spectral signal is carried out based on a calibrated CCD camera, and an underwater target absolute distance measurement value is obtained. Compared with the prior art, the application realizes accurate, fast and highly stable underwater distance measurement.

The invention provides a CPLD-based multi-fan rotating speed parallel acquisition and I2C transmission system and method, and relates to the technical field of computer hardware monitoring, and the CPLD-based multi-fan rotating speed parallel acquisition and I2C transmission system is characterized in that each fan of a multi-fan rotating speed acquisition module comprises a rotating speed feedback circuit for generating a TACH signal corresponding to the rotating speed; the CPLD control processing module is provided with a plurality of parallel signal interfaces which are communicated with a TACH signal line of the multi-fan rotating speed acquisition module and are used for acquiring, counting and processing TACH signals; and transmitting the processed rotating speed data, and obtaining the rotating speed data. The technical problems of high CPU resource occupation, poor expansibility and insufficient reliability in a conventional fan rotating speed monitoring scheme are solved, and the purposes of obtaining the fan rotating speed through a substrate management controller, adopting a special fan monitoring chip, internally integrating a plurality of frequency counters or timers, collecting TACH signals of a plurality of fans at the same time and converting the TACH signals into rotating speed values, reducing CPU loads and improving the fan rotating speed monitoring efficiency are achieved. And the expandability and the reliability of the system are improved.

The utility model provides a clamp-shaped grounding resistance tester test frequency calibration device, and relates to the technical field of calibration systems. The device comprises a shielding system, a measuring system, a connecting system and a fixing system, and the shielding system is used for placing a pincerlike grounding resistance tester to be detected and shielding electromagnetic interference; the measuring system comprises a current transformer, a digital multimeter and a frequency counter; the connection system comprises a copper rod, a copper core wire and a BNC wire, the copper rod and the copper core wire form a detected loop, and the BNC wire is connected with the current transformer, the digital multimeter and the frequency counter; the fixing system comprises a copper rod support and an insulating plate, the copper rod support is used for fixing the copper rod and enabling the copper rod to be vertical to the test table top, and concentric circles with different diameters are drawn on the insulating plate and used for positioning the copper rod. According to the device, the test calibration problem of the test frequency of the pincer-like grounding resistance tester and the electromagnetic interference problem are solved, and the traceability of the pincer-like grounding resistance tester is standardized by analyzing test data.

The invention provides a laser frequency hopping performance detection device, method and system and a cold atom interferometer, and belongs to the technical field of quantum measurement, the detection device comprises a reference laser, a high-speed photoelectric detector, a frequency discriminator, a reference frequency source, a PID controller, a voltage acquisition card and a microprocessor; the input end of the high-speed photoelectric detector is connected with the reference laser and the to-be-locked laser, and the to-be-locked laser outputs to-be-frequency-locked laser. The PID controller is connected with the to-be-locked laser, generates a voltage feedback signal and inputs the voltage feedback signal to a voltage control end of the to-be-locked laser; and the microprocessor is connected with the voltage acquisition card and the reference frequency source, and determines the frequency hopping speed of the laser to be locked according to the linear relationship between the frequency change of the laser to be locked and the voltage feedback signal. According to the detection device, in a field environment, the voltage feedback signal can be directly acquired through the voltage acquisition card to analyze the frequency hopping performance of the laser to be locked, the scheme is simple and easy to implement, and detection equipment such as a frequency counter does not need to be carried.

The present application relates to the technical field of laser, in particular to a frequency stabilization method with real-time frequency monitoring function and a laser structure, the frequency stabilization method adopts a frequency stabilization device, the frequency stabilization device comprises a laser, a fiber beam splitting module, a frequency stabilization module, a beat frequency module, a beat frequency signal monitoring unit and a frequency counter, and the fiber beam splitting module comprises a first fiber beam splitter and a second fiber beam splitter.The frequency stabilization method in the present application is realized based on the frequency stabilization device, in the frequency stabilization process, through the cooperative matching of the frequency stabilization module, the beat frequency module, the beat frequency signal monitoring unit and the frequency counter, on the basis of meeting the realization of the closed loop locking of the laser frequency, the key quantitative index of the laser frequency stability can be displayed in real time without any external expensive equipment, the frequency stabilization state is visualized, and one beat frequency signal is reserved to meet the deep analysis requirement of the user, so that the implementation cost and difficulty of the frequency stabilization method in the present application are low.

The invention provides a calibration method and system for a dual-channel synchronous sampling phase difference, and the method comprises the steps: converting the phase difference into a high-precision time interval signal, achieving the sub-nanosecond time measurement through a frequency counter, building a traceability path of the phase difference and a standard time reference, and achieving the calibration of the dual-channel synchronous sampling phase difference. According to the method, the problem of phase difference magnitude traceability deficiency in a low-frequency signal scene is effectively solved, the limitation that a traditional method depends on standard signal source comparison is broken, the dependence on an expensive high-end signal source is remarkably reduced, the calibration cost and the technical threshold are reduced, and meanwhile the measurement credibility is remarkably improved. The frequency band range involved by the method and the system comprises 10 Hz to 10 kHz, the phase difference coverage full range is-180 degrees to 180 degrees, for 100 Hz / 10 ms, the measurement result deviation of a frequency counter is smaller than 6 ns, the corresponding phase deviation is smaller than 0.0002 degrees or 3.5 microrad, a correction table of the synchronous sampling phase difference can be given through calibration under different frequencies and different phases, and the accuracy of the phase difference measurement result is further improved.

The present disclosure relates to a method and a device of a 425 nm wavelength reference construction based on fluorescence-induced effect. The method comprises: a continuously tunable laser, an atomic furnace, a chromium atomic beam, an optical frequency comb, a frequency doubling optical path, a bias-preserving fiber beam splitter, a bias-preserving fiber beam combiner, a beat-frequency detection optical path, an optoelectronic receiver, and a frequency counter atomic furnace.

Medical diagnostic devices and related methods of use are described in which one or multiple coils in a sensor, each coil connected with an RLC circuit and frequency counter, are held against a patient's head at predetermined cranial locations. Frequencies of the RLC circuit are measured and compared against those taken from known, control heads, to determine whether there is a medical problem and what type of problem. In some instances, too high of frequencies can reveal pooled blood in the head, a sign of hemorrhagic stroke, while too low of frequencies imply lack of blood supply, a sign of ischemic stroke. A head-mountable frame can assist a first responder in securing and guiding the coils and, along with fiducials, allow for automatic comparison of frequencies with the correct control data.

The invention relates to a reference clock generation circuit. Disclosed is a technique relating to a semiconductor circuit, and in particular to a circuit for generating a reference clock from a radio signal. A window is dynamically controlled at a circuit level that takes into account an external signal that is input to control a frequency according to a difference between an output of the digitally controlled oscillating circuit and a target frequency. The reference clock generation circuit may change a frequency of the output reference clock by selecting a target count value of the frequency counter as one of the plurality of groups according to an operation mode. The reference clock generation circuit may be controlled to prevent power from being supplied to the circuit when the output is stably locked to the target frequency, and the digitally controlled oscillation circuit is allowed to be controlled by the last input oscillation control word to perform free operation.

The application discloses a kind of heavy frequency self-calibration double optical frequency comb ranging systems and methods, the system includes double optical frequency comb light source module, interferometer ranging module and signal acquisition and data processing module.Double optical frequency comb light source module uses two optical frequency comb light sources with small heavy frequency difference.Interferometer ranging module converts the distance information to be measured into the flight time of signal optical frequency comb by Michelson interferometer, then uses double optical frequency comb interferometer to amplify the flight time from optical scale to radio frequency scale.Signal acquisition and data processing module obtains the heavy frequency size after undersampling by peak finding, intercepting, fast fourier transform, phase spectrum fitting and other operations to obtain the flight time in real time, to realize the self-calibration of the distance to be measured by periodic fast fourier transform and amplitude spectrum analysis.The application only uses double optical frequency comb interference signal itself and simple signal post-processing algorithm, without any external heavy frequency detection module and frequency counter, to realize accurate double optical frequency comb ranging.

The invention discloses a flow suppression control method for a multi-frequency reverse-phase excitation radial flow turbine, which is characterized in that a plurality of grooves are formed in the wall surface of a turbine case, and the grooves are used for generating generalized force opposite to the exciting force phase of a volute in the rotating process of blades, so that the exciting force of the volute is counteracted, and the amplitude of the blades is suppressed. According to the invention, the passive flow control principle is adopted, and the generalized force which is opposite to the original exciting force in phase and equal to the original exciting force in mode length is generated by forming the groove with the specific geometric configuration in the wall surface of the casing, so that the effective vibration suppression is realized, and meanwhile, the turbine performance is ensured to be basically unchanged.