51 results about "Standard test signal" patented technology

A method and apparatus for allowing a modem transmitting data in the data mode to initiate retraining mode due to changing line conditions. The modem inserts a test signal within the data received from a computer system. The data and test signal are encoded and sent over a network to a second modem. The second modem compares the test signal with a standard test signal, and if the test signal received is different from the standard test signal, the second modem initiates retraining of the modems to adjust for the varying line conditions.

The invention provides an onsite stable state precision calibration system of an electronic voltage transformer and a calibration method thereof. The method comprises the steps: a, the electronic voltage transformer is connected with a standard voltage transformer in parallel, and the same test voltage is applied to the standard voltage transformer and the tested electronic voltage transformer; b, a secondary analog voltage signal of the standard voltage transformer is converted into digital quantity in a manner of analog-to-digital conversion and the digital quantity is transmitted to an analysis processing unit of an electronic transformer stable state calibration system; c, the digital quantity output by the electronic voltage transformer is subjected to photoelectric conversion and then is connected with the host of the electronic transformer stable state calibration system via an Ethernet line; and d, the electronic transformer stable state calibration system analyzes and processes the acquired digital quantity of a standard voltage signal and the digital quantity output by the electronic transformer through the analysis processing unit to obtain a calibration value for specimens. The method provided by the invention can realize the stable state calibration for the onsite electronic voltage transformer, and has high calibration precision, speed and efficiency.

The invention relates to a system and a method thereof for checking the product quality. The system comprises a checking implement, a camera device and a checking module, wherein the checking implement is used for positioning a finished product to be checked, the camera device is arranged on the checking implement, the checking implement and the camera device correspond to each other without change, the checking module is used for processing digital signals; check data is generated in such away that standard check signals are irradiated or a product to be checked is input, and the camera device takes a picture and converts the picture signals into digital signals through the check module. The check method is as follows: quality condition is input by using an external interface, and digital picture data of a qualified product is used as a standard, the whole picture is divided into a plurality of pixel regions through the check module according to the specification demands, the picture data of the product to be checked in each pixel region is analyzed one by one in an absolute and relative comparison method so as to judge the location and the type of the defects so that the quality is judged to be good or bad. The system and the method thereof for checking the product quality can accurately judge the quality of the product to be checked, thereby lowering the error ratio of the check result.

The invention discloses an analog quantity merging unit transient state delay test method based on frequency scanning. Sudden-change quantities of a received standard source signal and a signal to be measured are judged in real time, a starting moment of a transient state process is determined, waveform signals are collected, the amplitude and the phase angle of each harmonic are calculated, the transient state delay corresponding to each harmonic is calculated, and ultimately, the ultimate transient state delay is calculated according to the amplitude of each harmonic and the transient state delay corresponding to each harmonic. Transient state transmission time is calculated through a weighting coefficient, test currents do not need to be output specially, universality is high, and the method is suitable for all merging units with low-pass filter coefficients, port modes and port protocols currently. A high-precision constant-temperature crystal oscillator is used for controlling timing sequence and eliminating errors, the transient state starting moment of tested data is guaranteed, and sampling precision of higher harmonics is improved by means of a four-step Bessel filter. The analog quantity merging unit transient state delay test method based on frequency scanning can be widely used in the field of relay protection and verification.

The invention discloses a digital output DCVT field calibration system. Based on the theory of an absolute delay digital output DCVT field calibration method, an independent front-end unit is used toachieve in-situ high-precision conversion of digital signals in standard channels. In particular, a high-precision AD acquisition unit of a DC electronic transformer calibrator is preposed, a converted data sequence is transmitted through an optical fiber to a front-end unit input interface of the DC electronic transformer calibrator, primary equipment and secondary equipment are isolated, and interference of secondary small voltage signal transmission of a standard voltage divider in field calibration can be avoided. The calibration system acquires a DC component through a DC component-containing wavelet coefficient to enhance the signal extraction accuracy. A test system based on a feedback time difference between a standard step signal and a calibrated DCVT for absolute delay is put forward, an uncertainty evaluation method is given through uncertainty source analysis on the calibration system, and the reliability of the calibration result is ensured.

The invention discloses a testing system and method for conducted susceptibility of cable bunch injection. The system comprises a control module, a signal generation module, a signal amplification module, a coupling module, an injection clamp, a monitoring clamp and a signal measurement module, wherein the control module is used for generating a control signal controlling the signal generation module and the signal measurement module to work; the signal generation module generates a standard testing signal according to testing standards under the control of the control module; the signal amplification module amplifies the standard testing signal generated by the signal generation module and then sends the standard testing signal into the coupling module for coupling; the coupling module isused for coupling the standard testing signal amplified by the signal amplification module to the injection clamp; the injection clamp is used for injecting the amplified standard testing signal intoa to-be-tested cable; the monitoring clamp is used for picking up a signal conducted by the to-be-tested cable and transmitting the signal to the signal measurement module; the signal measurement module is used for reading measurement data of the coupling module and monitoring clamp under the control of the control module. The testing system and method for the conducted susceptibility of the cable bunch injection have the advantage that on the basis of no additional purchase of other equipment, it can be ensured that testing is started from the testing frequency below 4kHz.

An embodiment of the invention discloses an automatic test system for network access of a set-top box, which comprises a digital television test signal generator, a digital television test transmitter, the set-top box, an audio analyzer, a video analyzer and a controller. The digital television test signal generator, the digital television test transmitter and the set-top box are respectively electrically connected with the controller, the controller is connected with the audio analyzer and the video analyzer via a USB (universal serial bus) and then a GPIB (general purpose interface bus). The digital television test signal generator is used for generating standard test signals, the digital television test transmitter is used for modulating the test signals into digital signals, the modulated digital signals serving as the test input signals are used for testing the set=top box, and the processed test signals are respectively transmitted to the corresponding video analyzer and the audio analyzer by the set=top box and then are analyzed and displayed. By the aid of the automatic test system for network access of the set-top box, parameters of the audio and the video can be tested automatically, human labor, time and hardware resources can be saved due to the fact that the system is operated by machine, and the testing efficiency can be improved.

The invention provides a flicker precision detection method for a digital electric energy quality monitoring terminal and a system thereof. The method comprises the steps that standard signals meeting the IEC61850-9-2 requirement are transmitted to the digital electric energy quality monitoring terminal; sampling is performed on the standard signals by the digital electric energy quality monitoring terminal and an MMS message is outputted; minute data of a short-term flicker index are confirmed according to the MMS message; and a short-term flicker measured value of the digital electric energy quality monitoring terminal is confirmed according to the minute data of the short-term flicker index. The IEC standard, detection precision and dynamic flicker detection capacity of the digital electric energy quality monitoring terminal can be identified, and flicker test capability of the electric energy quality terminal used for a digital transformer substation can be conveniently and rapidly assessed.

The invention discloses a control method for an intelligent socket. The method comprises the following steps of: A, after the socket is electrified, loading a load on a main control circuit to a normal work state in pre-set time; B, collecting a simulated current signal on the main control circuit at regular time; C, calculating an average value of the collected simulated current signal; D, taking the percentage of the average value, which is less than the average value of the simulated current signal, as a standard current signal, and storing the standard current signal; E, collecting a real-time current signal on the main control circuit and comparing the real-time current signal with the standard current signal; and F, if the real-time current signal is less than the standard current signal, switching off a power supply of a controlled circuit; otherwise, maintaining the power supply of the controlled circuit. The invention further discloses a control circuit which is matched with the control method and is used for the intelligent socket. The intelligent socket manufactured by the invention has the beneficial effects of convenience for use, free debugging of the circuit, high automation degree and energy saving.

The invention discloses a phasor measurement accuracy assessment method and assessment apparatus for a synchronized phasor measurement unit. The phasor measurement accuracy assessment method for a synchronized phasor measurement unit includes the following steps: according to synchronous recording data and synchronous phasor measurement data, acquiring a fundamental wave reconstruction waveform so as to obtain a residual error waveform; acquiring an in-band signal to noise ratio and an outband signal to noise ratio of the residual error waveform; by means of the in-band signal to noise ratio and the outband signal to noise ratio, respectively acquiring the uncertainty of synchronous phasor measurement and the signal to noise ratio of a power grid sampling signal; according to the input standard signal source setting, the in-band signal to noise ratio and the outband signal to noise ratio, obtaining the phasor measurement error caused by fundamental wave and interference; and acquiring the comprehensive assessment result about system measurement accuracy. The phasor measurement accuracy assessment method can realize on-line estimation of the uncertainty of synchronous phasor measurement when a PMU (Phasor Measurement Unit) is running normally, and can realize accuracy verification of the PMU by means of combination of a medium accuracy standard test signal source during the process of testing the PMU performance, thus improving the reliability and accuracy of assessment.

The invention discloses a gamut conversion method and device. The method comprises the steps that a standard test signal is converted into a display equipment RGB signal according to a space conversion matrix which is calculated according to original coordinates; result coordinates corresponding to the display equipment RGB signal are looked up, and target coordinates, to be displayed on a display screen, of the standard test signal are acquired; whether or not the difference between the result coordinates and the target coordinates is larger than a preset error is judged; and if the difference is larger than the preset error, the original coordinates are adjusted, and the standard test signal is converted into a new display equipment RGB signal according to a space conversion matrix which is calculated according to original coordinates obtained after adjustment until the difference between result coordinates corresponding to the new display equipment RGB signal and the target coordinates is smaller than or equal to the preset error. According to the method, the overrange signal problem is taken into account, system byte digit limitation is avoided, the error between the practical coordinates obtained after gamut conversion and the information source coordinates is small, the precision of the practical coordinates is high, and the color distortion problem can be eradicated.

The invention relates to a portable field calibration system of an electric energy meter. The system comprises a signal acquisition unit. A voltage sensor and a current sensor are connected with the signal acquisition unit electrically. A collected standard voltage signal and a collected standard current signal are transmitted to a signal detection unit; and a calibrated electric energy meter outputs a pulse signal to the signal acquisition unit. The signal acquisition unit is connected with a calibration platform electrically; the calibration platform compares the standard voltage signal and the standard current signal with the pulse signal emitted by the calibrated electric energy meter, thereby calculating an error of the calibrated electric energy meter. According to the portable field calibration system provided by the invention, because the voltage sensor and the current sensor employ open type structures, a running electric energy meter can be calibrated accurately under the circumstances that normal operation of the power system is not affected.

The invention discloses a television core test circuit. The television core test circuit comprises a control module, a voltage acqusition circuit and an audio acqusition module, wherein the control module is used for outputting a standard audio signal and a standard video signal to a television core and acquiring an LVDS (Low Voltage Differential Signaling) signal output by the television core; the voltage acqusition circuit is used for acquiring a voltage value of a preset position of a television motherboard and outputting the voltage value to the control module; the audio acqusition module is used for acquiring an audio play signal output by the television core and outputting the audio play signal to the control module; the control module is used for comparing the LVDS signal with the standard video signal, comparing the audio play signal with the standard audio signal and comparing the voltage value with the preset standard voltage; thus the test of the television core is realized. The invention also discloses a television core test system. The test difficulty of the television core is reduced.

An active noise reduction device includes a standard signal generator, adaptive filters, a control sound emitter, and an error signal detector. The standard signal generator generates a standard signal including harmonics of a fundamental frequency correlated with the control target sound. The adaptive filters each generates corresponding one of harmonic components of a control signal based on the standard signal. The adaptive filters each is for corresponding one of the harmonics. The control sound emitter emits a control sound based on the control signal. The error signal detector collects residual noise left over after interference between the control target sound and the control sound, and detects an error signal based on the residual noise. Each of the adaptive filters includes a step size determiner. The step size determiner sets the step size parameter based on a frequency variation in the corresponding one of the harmonic components of the standard signal.

The present invention discloses a current detection circuit. The circuit is configured for a power conversion device, and comprises a sampling unit, a mirror image unit and a detection unit, wherein the sampling unit is configured to connect with the power conversion device and configured to obtain the sampling current signals of the power conversion device, the mirror image unit is connected with the sampling unit and the detection unit and is configured to input the sampling current signal mirror images into the detection unit, and the detection unit is configured to generate current detection signals and feed back the control power conversion device according to the sampling current signals, the standard current signals and the standard voltage signals. The current detection circuit and the power conversion device provided by the embodiment of the invention realize the over-current detection of the output average load current through detection of output load so as to improve the precision of the over-current detection circuit and effectively reduce the number of the peripheral devices of the chips, and moreover, because the detection current is far smaller than the load current of the chips, the power consumption loss of the chips brought by the over-current detection circuit is effectively reduced.

The embodiment of the invention discloses a signal conversion device and a conversion method. The signal conversion device is used for being connected with a machine core board of an ultrahigh definition television and a display capable of supporting an HDMI signal, and comprises a signal receiving module, a signal conversion module and a CPU, wherein the signal receiving module is connected with the machine core board and used for receiving an initial signal output by the machine core board; the initial signal is an LVDS (low-voltage differential signaling) signal or a first V-BY-ONE signal; the signal conversion module is connected with the signal receiving module and the display separately, and is used for converting the initial signal into the HDMI signal according to an instruction and outputting the HDMI signal to the display; the CPU is in communication connection with the signal conversion module and used for transmitting the instruction to the signal conversion module. Through the signal conversion device, the machine core boards of different ultrahigh definition televisions can be matched with different displays, and the display still can normally display and output, so that research and development persons can debug the machine core boars of various ultrahigh definition televisions based on the displays capable of supporting the standard HDMI signal, the research and development efficiency is improved and the production cost is reduced.

The invention relates to an electronic voltage transformer online checking system which comprises a voltage sensing unit, a signal conversion unit, a signal transmission unit and a checking platform, wherein the voltage sensing unit is used for acquiring a primary voltage signal online; the output of the voltage sensing unit is used as a standard signal; after being processed by the signal conversion unit, the standard signal is transmitted to the checking platform by the signal transmission unit. The electronic voltage transformer online checking system disclosed by the invention uses a ring-shaped electric field sensing array as the voltage sensing unit and can acquire the primary voltage signal under the uninterruptible power condition. The voltage sensing unit does not need to be directly connected with a primary wire, but acquires the primary voltage signal in an electromagnetic induction manner, therefore, normal operation of a line is not influenced, and the problem of ferromagnetic resonance also does not exist.

The invention provides an error code detection device, which belongs to the technical field of communication detection. The error code detection device comprises a transmitting end and a receiving end, wherein the transmitting end is used for transmitting a test pseudorandom sequence code obtained through converting and processing a pseudorandom sequence code to a test device; and the receiving end is used for receiving a test sequence code outputted by the test device for error code detection, and the test sequence code is the sequence code outputted when the pseudorandom sequence code is transmitted through a to-be-detected device. The pseudorandom sequence code has good self correlation and good statistical properties. By using the pseudorandom sequence code as a standard test signal, the error code detection accuracy can be improved.

The invention discloses a method for automatically detecting television channel search performance. The method comprises the following steps: after a smart television is powered on and channels are searched, performing channel switching operation through an automatic testing script, and once a channel is switched, capturing screenshots through a preset screenshot script, and comparing similarity of the screenshots with preset standard testing signal images one by one, thereby detecting whether a smart television system has phenomena of channel omission, repeated signal search and signal interference; if the phenomena happen, stopping the testing script automatically, and generating testing reports automatically; positioning channel search problems by developers according to operation logs of an Android smart television.

The present invention discloses a method for obtaining a PSD (Power Spectral Density) of a vibration endurance test. The method comprises the steps of: obtaining initial test signals; performing signal checking of the initial test signals, and obtaining credible test signals; performing signal repairing processing of the credible test signals, and obtaining standard test signals; performing rain-flow statistics of the standard test signals according to a rain flow counting method, and obtaining a rain-flow statistics result; performing PSD analysis of the standard test signals, and obtaining an initial PSD curve; according to the rain-flow statistics result, performing a first iteration loop correction of the initial PSD curve, and obtaining a PSD curve after the first correction; the maximum value / the minimum value analysis of the standard test signals; and performing a second iteration loop correction of the PSD after the first correction according to a PSD evaluation criterion and damage computation, and obtaining a target PSD curve. The present invention further discloses a device for obtaining a PSD of a vibration endurance test. The method provided by the invention can obtaina target PSD curve suitable for the vibration endurance test.

The invention discloses a time synchronization control system of an off-grid photovoltaic power system, which comprises a time receiving circuit, a clock correction computation control circuit and an off-grid system drive control circuit, wherein the time receiving circuit has a receiving antenna, receives a radio standard time signal transmitted by a radio time launcher and sends the received signal to the clock correction computation control circuit; the clock correction computation control circuit is used for filtering and analyzing the standard time signal, comparing the standard time signal with an actual clock signal of the photovoltaic power system, correcting the actual clock signal and sending the corrected clock signal to the off-grid system drive control circuit; and the off-grid system drive control circuit is connected with at least two off-grid photovoltaic power systems and drives all the off-grid photovoltaic power systems according to the received corrected clock signal, so that all the off-grid photovoltaic power systems are kept synchronous. When the embodiment of the invention is used, the precise control over the time synchronization of the off-grid photovoltaic power systems is realized, and the construction cost of a project can be reduced.

Airplane bus cable test equipment and a test method are disclosed. The equipment comprises a portable case, a detection host and a detection sub-machine are arranged in the case, and the detection host comprises a power supply module, a man-machine interaction interface, a comprehensive test module, a host communication module and a test port. The detection sub-machine comprises at least one bus test signal transmitter, the bus test signal transmitter comprises a power supply module, a signal generation module, a sub-machine communication module and a test signal transmitting port, and during testing, a test instruction is input through the human-computer interaction interface of the detection host, the signal generation module of the detection sub-machine generates a matched standard test signal, the comprehensive test module analyzes the test signal to obtain a test result, and then the test result is sent to the human-computer interaction interface to be displayed.

The invention discloses an audio signal switching device, comprising an MCU (microprogrammed control unit) module (1), wherein an input interface of the MCU module (1) is connected with a computer (2); an output interface of the MCU module (1) is connected with an audio switch chip AS1747; the MCU module (1) transmits a switching command transmitted by the computer (2) to the audio switch chip AS1747; an input channel of the audio switch chip AS1747 is respectively connected to different audio equipment; an output channel of the audio switch chip AS1747 is connected to a standard signal test source (3); the switching command transmitted by the computer is received by virtue of the audio switch chip AS1747; to-be-switched audio equipment is switched into the corresponding channel, thus audio connection is built by the audio equipment and the standard signal test source. The switching device is simple in structure; switching between different audio equipment and the standard test signal source can be rapidly achieved; the problem of audio signal distortion in a switching process of an ordinary relay and an analog switch is avoided, and therefore, the communication quality is ensured.

The invention discloses a test signal parallel loading conversion circuit and a system-on-chip. The test signal parallel loading conversion circuit comprises an off-chip test signal receiving module and an on-chip parallel loading module which are connected with each other, wherein the off-chip test signal receiving module is used for receiving parallel test signals from a plurality of scanning test pins according to an off-chip clock rate and transmitting the parallel test signals to the on-chip parallel loading module according to an on-chip clock rate; and the on-chip parallel loading module is used for carrying out signal recombination on the received parallel test signal and encoding the recombined signal into a standard test signal stream conforming to an NOC standard protocol so asto carry out functional test on at least one target IP core on the chip. According to the circuit, the situation of missed detection of manufacturing defects in an early test stage can be effectivelyprevented, and test cost of products can also be greatly reduced.

The invention discloses a Gigabit Ethernet switching device, which comprises an MCU (Microprogrammed Control Unit) module (1), wherein an input interface of the MCU module (1) is connected with a computer (2); an output interface is connected with a gigabit Ethernet switch chip TS3L500AE; the MCU module (1) sends a switching order sent by the computer (2) to the gigabit Ethernet switch chip TS3L500AE; an input channel of the gigabit Ethernet switch chip TS3L500AE is respectively connected with different Ethernet devices; an output channel is connected with a standard signal test source; (3) adopting the gigabit Ethernet switch chip TS3L500AE to receive the switching order sent by the computer, and switching the Ethernet devices to be switched to corresponding channels, so that Ethernet connection is built between the Ethernet devices and the standard signal test source. The switching device is simple in structure, can quickly realize gigabit Ethernet switching between the different Ethernet devices and the standard signal test source, avoids electromagnetic induction generated during the switching process of a common relay and an analog quantity switch, and ensures communication quality.

The embodiment of the invention discloses a delay calibration parameter determination method and device, electronic equipment and a storage medium. The method comprises the steps that according to analternative delay value set corresponding to to-be-calibrated data ports, a Monte Carlo tree of delay values is constructed, wherein nodes on each layer of the Monte Carlo tree correspond to alternative delay values of the same to-be-calibrated data port; according to delay values of iterative value paths in the Monte Carlo tree, delay values needed for all the to-be-calibrated data ports to output standard test signals are adjusted, and a target value path is obtained; and according to all the nodes included in the target value path, delay values corresponding to all the to-be-calibrated dataports are determined. Through the technical scheme in the embodiment, the technical effect of determining delay calibration parameters automatically, efficiently, rapidly and accurately is achieved,no manpower cost investment is needed, an existing delay calibration parameter determination mode is optimized, and the determination efficiency of the delay calibration parameters is improved.

The embodiment of the invention discloses a vehicle-mounted controller test method, device and system. The method comprises the steps of determining a test input voltage, a test load current and a power voltage for a to-be-tested logic connection element in a vehicle-mounted controller; based on the test input voltage and the power supply voltage, applying an input signal to the vehicle-mounted controller, and obtaining an output signal of the vehicle-mounted controller under the input signal; generating a test signal according to the output signal and the test load current; and determining atest result of the logic connection element according to the test signal and a preset standard test signal. Therefore, the vehicle-mounted controller can be tested.

The embodiment of the invention discloses an audio signal transmission device and electronic equipment. The device comprises an isolation circuit, a step-down circuit, a microphone and a coupling circuit, wherein an input end of the isolation circuit is electrically connected with a power supply channel of a power supply signal, and used for isolating an interference signal included in the input power supply signal to obtain a standard voltage signal; an input end of the step-down circuit is electrically connected with an output end of the isolation circuit, and used for adjusting the input standard voltage signal into a standard step-down signal matched with the microphone; a power input end of the microphone is electrically connected with an output end of the step-down circuit, and usedfor acquiring sound under the triggering action of the input standard step-down signal and converting sound into a speech signal; and an input end of the coupling circuit is electrically connected with an output end of the microphone, and used for outputting the coupled and received speech signal to the power supply channel of the power supply signal. Through adoption of the audio signal transmission device in the embodiment of the invention, the anti-interference ability of audio signal transmission can be enhanced.

The invention discloses a portable information source simulator for an active transponder, and belongs to the field of railway signals. The portable information source simulator comprises a first signal control module, a second signal control module, a signal combination module and a cable simulation module, wherein the first signal control module is used for providing a transponder message for the active transponder, the second signal control module is used for providing a bias voltage signal for the active transponder and providing energy needed by normal operation of the active transponder, the signal combination module is used for coupling the transponder message with the bias voltage signal to obtain a standard interface signal, and the cable simulation module is used for simulating transmission cables with different lengths between an LEU (lineside electronic unit) and the active transponder. The portable information source simulator can simulate the actual LEU to provide information sources for the active transponder and can simulate the cables with particular length specifications, is convenient to carry, and has the advantages that the portable information source simulator is simple to use, low in power consumption and easy to popularize, cost is saved and the like.