229results about "Altering measuring range circuits" patented technology

The embodiment of the invention provides a signal envelope detection circuit and a chip. The circuit comprises N cascaded first limiting amplifiers, a plurality of first rectifiers and at least one first level conversion circuit, the power supply voltage of the first-stage first limiting amplifier is a first voltage; each of the first limiting amplifier and the first rectifier comprises a tail current tube, and the tail current tubes are transistors for providing bias current; the first level conversion circuit is used for reducing the voltage output by the first limiting amplifier and then outputting the reduced voltage to a post-stage first limiting amplifier and a corresponding first rectifier, so that the voltage between a collector electrode and an emitter electrode of a corresponding tail current tube is smaller than a breakdown voltage; and a first level conversion circuit is connected between at least the first-stage first limiting amplifier and the second-stage first limiting amplifier so as to at least reduce the voltage output by the first-stage first limiting amplifier. According to the embodiment of the invention, the dynamic range of the signal envelope detection circuit can be expanded.

The invention provides a current measuring circuit which comprises a micro-control unit and at least two measuring range circuits, and each measuring range circuit comprises a resistor, an MOS tube and an operational amplifier. The resistor of the previous measuring range circuit is connected in series with the resistor of the next measuring range circuit, the resistor of the first measuring range circuit is connected with power supply equipment, and the resistor of the last measuring range circuit is connected with a load to be measured; the micro-control unit is used for traversing the output voltage of the operational amplifier of each range circuit in sequence; if it is determined that target voltages on the two sides of a resistor of the measuring range circuit are smaller than a preset threshold value based on the output voltage, target current of a to-be-measured load is determined based on the output voltage and the resistance value of the resistor; and if the target voltage is not less than the preset threshold value, continuing to traverse the output voltage of the operational amplifier of the next range circuit. According to the technical scheme of the invention, the current measurement circuit meets the measurement requirements of a plurality of current ranges, the current ranges can be automatically switched, and the current output is not interrupted.

The invention relates to a measuring range dynamic adjusting method based on amplitude parallel estimation, which comprises the following steps of: (1) acquiring N current signal sampling points at a sampling rate fs, and calculating the amplitudes of the maximum N / 4 sampling points in the N sampling points in parallel; (2) storing N / 4 sampling points and the corresponding measuring range interval A; (3) continuously carrying out k times of signal sampling to obtain k groups of range interval sets {A1, A2,..., Ak}, and selecting the latest four groups of range intervals to carry out combined judgment; (4) if the four groups of measuring range intervals are consistent, keeping the current measuring range; if a wide-range interval occurs in the last two groups, switching to a wide range; and (5) carrying out trend estimation based on nearly five actual measuring range intervals. According to the invention, the key problem of the intelligent monitoring system in a high dynamic range signal monitoring scene is solved, the intelligent monitoring system can accurately judge the signal range and quickly adjust the range, and the loss of effective signals is reduced.

The current sensor may include a current detection unit that outputs a detection signal corresponding to a magnetic field generated in a conductor when a measurement current flows, and a signal processing unit that processes the detection signal to output an output signal. The signal processing unit may include a memory unit that stores a plurality of current sensitivity parameters corresponding to a plurality of current sensitivities that can be set for the current sensor, and a sensitivity setting unit that sets the current sensitivity of the current sensor based on one of the plurality of current sensitivity parameters stored in the memory unit.

The invention discloses a multichannel parallel level conversion circuit test system, which relates to the technical field of circuit test and comprises a test host, a multichannel parallel level conversion circuit, a signal source module, a signal acquisition module, a control module and a display module. The test host performs test logic verification on the whole process of the circuit test, the multichannel parallel level conversion circuit serves as a target circuit to be subjected to circuit test, a test signal of the circuit test is generated according to the signal source module, and a test case of the test signal is constructed. The signal acquisition module acquires an output signal of the multichannel parallel level conversion circuit, and generates a circuit tuning output signal after signal gain, signal noise optimization and frequency band filtering, the control module performs circuit testing on a target circuit according to a test case and the circuit tuning output signal, and finally, the control module performs circuit testing on the target circuit according to the test case and the circuit tuning output signal. And the display module visually displays the test result.

The invention provides a range switching circuit, a current detection circuit and an alternating current measuring instrument, and relates to the technical field of electric measuring instruments. The range switching circuit comprises a current input port which comprises a positive terminal and a negative terminal; the current and voltage conversion unit comprises a plurality of range gating branches, each range gating branch comprises a primary coil, a dotted terminal of the primary coil is electrically connected with the positive terminal, and a synonym terminal of the primary coil is electrically connected with the negative terminal; the bidirectional voltage limiting circuit is connected in parallel with the current input port and comprises a positive voltage limiting circuit and a negative voltage limiting circuit which are connected in parallel; the input negative electrode of the compensation unit is electrically connected with the dotted terminal of the primary coil, and the input positive electrode and the output end of the compensation unit are electrically connected with the synonym terminal of the primary coil. According to the invention, the amplitude of current impact on the sampling resistor can be obviously reduced, the damage caused by inconsistent measuring range is avoided, and the overall reliability of the alternating current measuring instrument is improved.

The invention relates to an on-line monitoring device and system based on an alternating current arrester. The on-line monitoring device comprises a basic monitoring unit, an environment sensing unit, a relay unit, a control unit and a calibration unit. The basic monitoring unit comprises a Rogowski coil 1 for monitoring the leakage current of the lightning arrester and a Rogowski coil 2 for monitoring the impact current. And the relay unit is controlled by the control unit and controls the working states of the Rogowski coil I and the Rogowski coil II. The environment sensing unit is used for monitoring environment parameters around the lightning arrester, the control unit judges environment parameter error coefficients according to the environment parameters and then feeds back the environment parameter error coefficients to the calibration unit, and the calibration unit forcibly corrects monitoring results. The measuring range can be automatically switched, high-precision monitoring is achieved through the first Rogowski coil in the case of low current, the second Rogowski coil is automatically switched to conduct wide-range monitoring in the case of impact current, the two Rogowski coils do not affect each other, and the measuring device has the advantages of being low in energy consumption and high in precision. And the calibration unit forcibly corrects the monitoring result, so that the detection precision of the device at low temperature is improved.

The invention discloses an intelligent fault prediction method and system for an electric vehicle charging pile, and relates to the technical field of intelligent fault prediction of charging piles, and the method comprises the following steps: carrying out the quantification of the sensitivity of historical magnetic flux detection through the output of a Hall sensor; taking the outputs of a plurality of different Hall sensors as a plurality of magnetic flux detection sensitivities; obtaining interference data of current load change on the magnetic field and detection quality data; based on a bp neural network algorithm, constructing a Hall sensor output evaluation model; enabling the output of the Hall sensor output evaluation model to correspond to the output of the corresponding Hall sensor, constructing a two-dimensional display model, carrying out the data analysis of the two-dimensional display model, obtaining the improved Hall sensor output, and enabling the improved Hall sensor output to serve as the magnetic flux detection sensitivity to be applied to the fault prediction of the cable of the charging pile. The problem that the accuracy and the false alarm rate of fault detection cannot be effectively balanced in cable fault detection through magnetic flux in the prior art is solved.

The invention discloses an automatic measuring range switching method and system for an electric measuring instrument, and relates to the technical field of electronic measurement, and the method comprises the steps that a measuring range control module analyzes a measuring range instruction and calculates a relay control time sequence of a target measuring range gear; and the execution driving module drives the multi-path relay group to be switched to the target range gear according to the relay control time sequence. According to the invention, the execution driving module is configured with a multi-path relay group composed of a high-precision relay channel, a power relay channel and a high-voltage relay channel, and a heterogeneous hardware design concept of a special relay is adopted for different measurement requirements. Therefore, one instrument can give consideration to the precision requirement of micro-parameter measurement and the safety requirements of power and high-voltage measurement at the same time, the limitation of measuring range design of a traditional instrument is fundamentally broken through, and the application scene and the comprehensive testing capability of the electric measuring instrument are greatly widened. And a solid hardware foundation is provided for developing a multifunctional and wide-range general electric measurement platform.

The invention discloses a single-magnet-ring dual-processing-circuit switching wide-range leakage current sensor and method. A magnetic core works in a deep magnetic saturation state based on a magnetic modulation principle and is used for sensing a leakage current signal; the square wave self-oscillation circuit is used for sending a square wave signal to the coil by utilizing the inductance effect of the coil; each of the two signal processing circuits comprises a filter, a proportional amplifier and a lock-in amplifier, and only amplification factors of the proportional amplifiers are different, and the proportional amplifiers are used for processing induced leakage current signals; and the microprocessor is used for analyzing and processing the signal output by the signal processing circuit. The system can monitor the insulation state of the energy storage system in real time, effectively improves the safety and reliability of the system, and is suitable for photovoltaic power generation, wind power generation and other application scenes related to the energy storage system.

The invention discloses a voltage calibrating device of an insulation resistance meter, which comprises a measuring range switching module, an amplification module, a time delay module, an acquisition module and a control module, and is characterized in that the measuring range switching module is electrically connected with a to-be-calibrated insulation resistance meter, the control module and the amplification module, and the time delay module is electrically connected with the amplification module, the control module and the acquisition module; the acquisition module is electrically connected with the control module; the measuring range switching module is used for switching a measuring range according to a measuring range switching signal so as to output a divided voltage corresponding to the switched measuring range to the amplification module, and the time delay module is used for delaying the amplification signal for a preset time length according to a time delay control signal during measuring range switching and then transmitting the delayed amplification signal to the acquisition module; the control module is used for determining a to-be-calibrated measuring range matched with the collected voltage signal and outputting a corresponding measuring range switching signal and a corresponding delay control signal. According to the invention, the problem of voltage jump during range switching is effectively solved, the verification precision and stability are improved, and manual operation for range switching is not needed.

The invention discloses a frequency converter, a current sampling circuit thereof and a three-phase current sampling method of a motor, the frequency converter is suitable for driving the motor in a compressor, and the current sampling circuit comprises a single-resistance sampling unit configured to perform current sampling at a voltage effective vector moment so as to obtain three-phase current of the motor; the multi-resistance sampling unit is configured to perform current sampling at a voltage zero vector moment so as to obtain three-phase current of the motor; and the switching control unit is configured to acquire parameters of the motor, determine a switching index according to the parameters of the motor, and select one of the single-resistor sampling unit and the multi-resistor sampling unit to perform current sampling based on the switching index. The current sampling circuit can solve the problems that the noise of the motor is large due to single-resistor sampling and the performance of the motor is reduced due to multi-resistor sampling, so that the performance of the motor is improved.

The invention provides a metering method and system for high-accuracy dynamic electric energy. The metering method comprises the following steps: carrying out synchronization processing on sampling signals of voltage and current; dynamically adjusting the window length of each sampling signal according to the active power stability of the sampling signals based on an adaptive non-overlapping window algorithm, and calculating the real-time power of the sampling signals; and according to the accuracy grade of the electric energy meter and the fluctuation of the real-time power of the sampling signal, adaptively adjusting a power threshold, and realizing accurate metering of dynamic electric energy. The accuracy of electric energy metering is improved.

The utility model discloses a dynamic range current measurement module which comprises a shunt resistance switching unit, a 24-bit precision ADC unit, an MCU processing unit, a crystal oscillator unit, an isolation unit, a 485 interface unit and a power supply unit. The shunt resistor switching unit is used for dynamically selecting shunt resistors with different resistance values according to the magnitude of the current to be measured so as to realize current measurement in a range of 10 uA to 10 A, the shunt resistor of 1 ohm is used in a range of 10 uA to 20 mA, and the shunt resistor of 10 m ohm is used in a range of 20 mA to 10 A; the 24-bit precision ADC unit is used for collecting the analog current signal passing through the shunt resistor and converting the analog current signal into a digital signal; according to the utility model, the dynamic range current measuring module is provided, so that when the current measuring range span is large, the measuring range can be automatically switched, and a tester does not need to replace testing equipment with different measuring ranges; measurement data can be continuously acquired; the electrical isolation loop allows the measurement point to be arranged at any position: a power supply or return wire, measuring part or all of the current.

A current measurement system, comprising a plurality of parallel sensing circuits, each sensing circuit configured to measure a respective range of voltage corresponding to a current through a load, wherein each sensing circuit is triggered to initiate measurement of a voltage across the load in response to a buffer current through a common buffer reaching a respective threshold, a buffer circuit for inputting a virtual ground voltage or a virtual ground current to the load and to the plurality of parallel sensing circuits, the virtual ground voltage corresponding to the voltage across the load or the current through the load, and a processor coupled to the plurality of parallel sensing circuits, wherein the processor is configured to combine data representing voltage measurements from the plurality of parallel sensing circuits to determine the current through the load.

The utility model discloses a multi-range current acquisition circuit, which comprises a load current acquisition circuit and a current bypass circuit, the load current acquisition circuit is connected in series between a power supply and a load resistor RX, and the current bypass circuit is connected in parallel with one side of the load current acquisition circuit. According to the utility model, the current bypass circuit is designed to be connected in parallel with one side of the load current acquisition circuit, so that current acquisition is not influenced after normal switching of the load current acquisition circuit, and a new current path can be provided when the acquisition circuit is not switched so as to ensure that the load at the output end can work normally.

The invention discloses a double-range current measurement system based on a solid-state relay, and relates to the technical field of current measurement. The system comprises a closed-loop Hall current sensor, a first shunt resistor, a second shunt resistor, a solid state relay (SSR), a Hall conditioning IC and an external controller. Two shunt resistors with different resistance values are dynamically switched through a solid-state relay, and compatibility of low-current high-precision measurement and high-current wide-range measurement is achieved. The method solves the problems that the precision and range of an existing single-range sensor are difficult to consider, double sensors are high in cost, mechanical relays have defects and the like, has the advantages of low cost, high reliability, good measurement precision and the like, and is suitable for wide-dynamic-range current measurement scenes such as an energy storage system and the like.

The embodiment of the invention provides a signal envelope detection circuit and a chip, the signal envelope detection circuit comprises N cascaded first amplification circuits, the input end of the first-stage first amplification circuit is used for receiving a target input signal; m cascaded attenuation circuits, wherein the input end of the first-stage attenuation circuit is used for receiving a target input signal; m second amplification circuits, wherein the input end of each second amplification circuit is correspondingly connected with the output end of one attenuation circuit; the output end of each first amplifying circuit and the output end of each second amplifying circuit are connected with the input end of one rectifier; the output ends of all the rectifiers are connected together and are used for outputting a target output signal; wherein N and M are integers greater than 1; the N first amplification circuits and the M second amplification circuits have the same amplification factor. According to the embodiment of the invention, the dynamic range of the signal envelope detection circuit can be expanded, and the detection accuracy is improved.

The invention discloses a three-phase line current wide-range measuring device and method based on TMR. The measuring device comprises a TMR mutual inductor array and a data processing unit module. The mutual inductor array is composed of M rows and three columns of TMR mutual inductors, each column of mutual inductors is correspondingly arranged vertically below the three-phase line, and the measuring ranges of the mutual inductors in each row are different; the data processing unit module calculates the three-phase line current under the corresponding measuring range according to the data acquired by each row of mutual inductors; selecting a row of mutual inductors which do not exceed the range at the current moment and have the minimum error, and taking the correspondingly obtained three-phase line current as the initial constant current; and selecting a row of mutual inductors which currently exceed the measuring range and have the maximum measuring range, and correcting the initial constant current by using the predicted current calculated by the mutual inductors to obtain the final current of the three-phase line at the current moment. According to the invention, high-precision measurement of three-phase line current is maintained while the measuring range is greatly increased, and the problem of data abrupt change possibly occurring during switching of different measuring ranges at present is solved.

The invention discloses a seamless range switching system and a seamless range switching method for instrument current measurement. The seamless range switching system comprises a digital-to-analog converter, an error amplifier, a first driving circuit, a first current measurement circuit, a clamping circuit, a second driving circuit, a second current measurement circuit, two analog-to-digital converters and a field programmable gate array. The first current measuring circuit converts 10 [mu] A to 30 mA low current into a first voltage signal to form a negative feedback closed loop. When the first voltage signal reaches a Zener breakdown threshold value, the clamping circuit outputs a trigger signal to start the second driving circuit, so that the two driving circuits jointly provide a total current of 30mA to 500mA for the load; the two analog-to-digital converters perform synchronous sampling, and the field programmable gate array selects digital signal output which is in a linear measurement range and has an error not exceeding + / -0.05% of a full scale. No mechanical switch exists in the switching process, the current is uninterrupted, and wide-range high-precision continuous measurement is achieved.

A measuring system comprises a voltage converter circuit that converts and outputs a voltage between a first terminal and a second terminal, and a computing device that detects anomalies in the voltage converter circuit. The voltage converter circuit comprises: a first output circuit that outputs a first output voltage obtained by multiplying a potential of the first terminal with respect to a predetermined reference potential by a conversion gain; a second output circuit that outputs a second output voltage obtained by multiplying a potential of the second terminal with respect to the reference potential by a conversion gain; and a third output circuit that outputs a third output voltage obtained by multiplying a voltage between the first terminal and the second terminal by a conversion gain.The conversion gains of the first output circuit, the second output circuit, and the third output circuit can be set to values ​​of at least one first group and one second group, and the ratio between a first group conversion gain and a second group conversion gain set in the third output circuit differs from the ratio between a first group conversion gain and a second group conversion gain set in the first output circuit or the second output circuit.The computing device comprises the following: a voltmeter which measures the first output voltage, the second output voltage and the third output voltage, and a diagnostic unit which, using conversion gains of a selected group, which is one of the first group and the second group, calculates a first conversion value, a second conversion value and a third conversion value corresponding to input voltages of the first output circuit, the second output circuit and the third output circuit, based on the first output voltage, the second output voltage and the third output voltage, and determines that an anomaly exists if the sum of the first conversion value and the second conversion value deviates from the third conversion value by at least one predetermined value.

A battery management device according to one embodiment includes a first comparator that compares a voltage of a battery cell with a first reference voltage, a switching circuit that sets a path electrically connecting the battery cell to a first path or a second path based on a comparison result by the first comparator, and an impedance calculation unit that calculates an impedance of the battery cell based on a first voltage applied via the first path or a second voltage applied via the second path.

The invention relates to the technical field of keyboard resistance measurement, and discloses a high-efficiency keyboard resistance measurement method, which comprises the following steps of: starting up and initializing an impedance measurement box; closing an impedance detection channel, and adjusting a current limiter until the maximum amplifier is minimized, so that the impedance measurement box is in a standby state; when the keyboard measurement function is started, a detection channel between the impedance measurement box and the keyboard is opened; whether the current value is too small or not is measured, and if the measured current value is too small, the current limiter is reduced; and measuring whether the amplification factor of the amplifier is too small, and increasing the amplification factor when the amplification factor is too small. The 5V power supply is arranged between every two pins of the keyboard, the current probe and the amplifier are connected to the negative electrode of the power supply, and the output signal of the amplifier is fed back to the control circuit for resistance calculation, so that the calculated resistance can be quickly fed back to a computer end for recording, and the efficiency of keyboard resistance measurement is improved.

A current measurement circuit includes an operational amplifier, an input connector, a gain control sub-circuit, and a measurement output. The operational amplifier includes two inputs and an output. The input connector is for connecting the two inputs across a current-sense resistor. The gain control sub-circuit is connected to the output and includes a switch operable to select a current path from a plurality of current paths. The measurement output is connected to the gain control sub-circuit for outputting a signal indicating a measured current based on a selected current path. The gain control sub-circuit is configured to select a gain across the operational amplifier based on a ratio between the input connector and the selected current path.

A frequency converter and a current sampling circuit thereof, and a three-phase current sampling method for a motor. The frequency converter (1000) is suitable for driving a motor (M) in a compressor. The current sampling circuit comprises: a single-resistor sampling unit (10) configured to perform current sampling at a voltage effective vector moment to obtain three-phase currents of the motor (M); a multi-resistor sampling unit (20) configured to perform current sampling at a voltage zero vector moment to obtain three-phase currents of the motor (M); and a switching control unit (30) configured to acquire a parameter of the motor (M), determine a switching index on the basis of the parameter of the motor (M), and select one of the single-resistor sampling unit (10) and the multi-resistor sampling unit (20) on the basis of the switching index to perform current sampling.

The utility model provides a kind of photoelectric sensor particle detection device and equipment based on double channel detection, it is related to optical particle detection technical field.The device sensor sampling circuit output end is connected with sampling signal distribution circuit input end;Sampling signal distribution circuit first output end is connected with first signal gain circuit input end, and second output end is connected with second signal gain circuit input end;First signal gain circuit output end is connected with first analog-digital conversion circuit input end;Second signal gain circuit output end is connected with second analog-digital conversion circuit input end;The gain coefficient of first signal gain circuit is greater than second signal gain circuit;The output end of first analog-digital conversion circuit and second analog-digital conversion circuit is connected with digital signal processing circuit.The utility model can make signal pass through different gain amplifier, double ADC sampling, make one way channel satisfy small particle measurement, another way satisfies large particle measurement, and the electrical signal of larger particle and smaller particle can be considered.

The present invention relates to electronic component measurement technology, and discloses a method and circuit for automatic measurement of voltage, resistance and capacitance; the method comprises an external signal input circuit, an internal switch network circuit, a reference signal output and current source generation circuit, a channel switching and ADC acquisition circuit and a comparator output circuit; the external signal input circuit is connected to the internal switch network circuit, the internal switch network circuit is connected to the channel switching and ADC acquisition circuit and the reference signal output and current source generation circuit, and the external signal input circuit comprises a resistor R5 and an input port A1, a resistor R6 and an input port A2, and a resistor R7 and an input port A4. The present invention simplifies the measurement circuit of a voltage, resistance and capacitance meter, and only three resistors are required to automatically measure voltage, resistance and capacitance, and there is no need to use relays and dials to switch gears, and the internal automatic range is determined for measurement; the design is safe and reliable, the volume is small, and the manufacturer's production cost is reduced and production efficiency is improved.

The embodiment of the present disclosure provides a signal envelope detection circuit and chip, the circuit includes N cascaded first limiting amplifiers, multiple first rectifiers and at least one first level conversion circuit; the power supply voltage of the first limiting amplifier of the first stage is the first voltage; the first limiting amplifier and the first rectifier both include a tail current tube, which is a transistor that provides a bias current; the first level conversion circuit is used to reduce the voltage output by the first limiting amplifier and output it to the first limiting amplifier and the corresponding first rectifier of the subsequent stage, so that the voltage between the collector and the emitter of the corresponding tail current tube is less than the breakdown voltage; at least the first level conversion circuit is connected between the first and second first limiting amplifiers to at least reduce the voltage output by the first limiting amplifier of the first stage. The embodiment of the present disclosure can expand the dynamic range of the signal envelope detection circuit.

The present invention provides a high-accuracy dynamic electric energy metering method and system, comprising: synchronizing voltage and current sampling signals; dynamically adjusting the window length of each sampling signal based on the active power stability of the sampling signal using an adaptive non-overlapping window algorithm, and calculating the real-time power of the sampling signal; and adaptively adjusting the power threshold based on the accuracy level of the electric energy meter and the fluctuation of the real-time power of the sampling signal, thereby achieving accurate dynamic electric energy metering. This improves the accuracy of electric energy metering.