163results about "Altering measuring range circuits" patented technology

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 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 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 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 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 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 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.

Aspects of the invention provide for qualifying a new meter (30) with specific power supply (10) requirements. In one embodiment, aspects of the invention include a system (100), including: an electric meter (30) having a housing; and a voltage-modifying device (20) connected to the electric meter (30) for modifying a received voltage, such that the electric meter (30) operates in accordance with a predetermined power supply (10) requirement, wherein the voltage-modifying device (20) is located within the electric meter (30) housing or external to the electric meter (30) housing.

The invention discloses a high-precision wide-range current detection circuit which comprises an auxiliary operational amplifier A1, a power tube MP, a sampling tube MS, a PMOS tube PM1, a resistor RS, an operational amplifier OP, a charge pump, a driving module and a high-voltage domain floating ground module. An auxiliary operational amplifier A1 is adopted to forcibly balance source electrode potentials of a sampling tube MS and a power tube MP, source electrode voltage of the power tube MP is sampled and fed back to an operational amplifier OP, an output signal of the operational amplifier OP is transmitted to a driving module, power supply of the driving module is provided by a charge pump and a high-voltage domain floating ground module, and the driving module dynamically adjusts grid electrode voltage of the power tube MP. According to the invention, the mismatch of the operational amplifier input end is reduced, and the current detection proportion precision is kept within the maximum-to-minimum range of the load current.

The current sensor may include a current detection unit that outputs a detection signal corresponding to the magnetic field generated in a conductor when a measurement current flows, and a signal processing unit that outputs an output signal by processing the detection signal. The signal processing unit may include a storage unit that stores a plurality of current sensitivity parameters corresponding to each of 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 storage unit.

The invention provides a dynamic range response scanning voltage system. The dynamic range response scanning voltage system comprises a main high voltage generation circuit, a quick response high voltage control circuit, a high voltage range circuit and a low voltage range circuit, wherein the main high-voltage generation circuit is used for inverting a low-voltage DC power supply into a stable high-voltage DC power supply and outputting the stable high-voltage DC power supply to the high-voltage range circuit and the low-voltage range circuit; the high-voltage range circuit is used for controlling and outputting a high-voltage range part by modulating a high-voltage optocoupler; the low-voltage measuring range circuit is used for controlling and outputting a low-voltage measuring range part by modulating a high-voltage optocoupler; and the quick response high-voltage control circuit is used for controlling the high-voltage measuring range circuit and the low-voltage measuring range circuit to jointly realize voltage scanning in a set voltage range, and the waveform of the scanning voltage is controlled by a program. The invention has the advantages that: a 0.1-+ 8000V high-voltage scanning interval can be realized, the high-voltage response rate is superior to 1 millisecond / kilovolt, and the high-voltage resolution is 0.1 V.

The invention relates to a multi-range voltage sensor and a voltage measuring method thereof, and belongs to the technical field of sensors. Wherein the power supply unit comprises two isolated voltage-stabilizing power supply sub-units, and the active noise reduction unit is connected between the high-voltage side voltage-stabilizing power supply sub-unit and the processing unit for noise reduction; the voltage dividing unit is used for accessing to-be-measured high voltage and dividing the high voltage to output a voltage sampling signal; the processing unit is used for processing the voltage sampling signal; the V / I conversion unit is used for converting the voltage sampling signal into a current sampling signal according to a specified proportion; the fluxgate detection unit is used for detecting the current value of the current sampling signal so as to output a current detection signal, and the current value reflected by the current detection signal and the current value reflected by the current sampling signal are in a first fixed proportion; the sampling unit is used for converting the current detection signal into a voltage detection signal according to a second fixed proportion and outputting the voltage detection signal. The high voltage to be measured is measured based on the working principle of the fluxgate, and the voltage measurement precision can be remarkably improved.

The invention discloses an alternating current detection circuit, an LED driving power supply and a lighting device, and relates to the technical field of LED power supply control, the circuit is connected between an alternating current power supply and a microcontroller, and the circuit comprises a signal rectification module used for converting an alternating current input voltage into a full-wave rectification signal; the signal conversion module is used for processing the full-wave rectification signal and outputting a pulse filtering signal and a direct-current voltage signal of which the amplitude tracks the peak value of the full-wave rectification signal; the reference generation module is used for generating a reference voltage signal in a preset proportion with the peak value of the full-wave rectification signal according to the direct-current voltage signal; and the signal comparison module is used for comparing the pulse filtering signal with a reference voltage signal and outputting a pulse signal of which the frequency is the same as that of the full-wave rectification signal to the microcontroller.

An amplifier device for receiving currents, comprising a first current path for measuring smaller currents of less than 100 pA, an input amplifier device included in the first current path, having at least one first amplifier, an output, an inverting input, a first feedback path connecting the output to the inverting input, and a feedback element included in the first feedback path, wherein the first amplifier has at least one protective element, a second current path for measuring larger currents with a maximum current of at least 10 times the current to be received in the first current path, characterized in that at least one of the protective elements of the amplifier is part of the second current path.

A method is provided for examining the cathodic protection of a metallic and in particular ferromagnetic pipeline. An inspection device is also provided for examining the cathodic protection of a pipeline, in particular of a ferromagnetic pipeline. The inspection device is formed to be able to pass through the pipeline and in particular be driven by the medium, and includes a magnetizing device serving to create an alternating magnetic field. A magnet unit and a measuring device are provided, and includes at least one magnetic field sensor serving to measure a magnetic field formed on the inner side of the wall of the pipeline.

The present invention belongs to the field of measurement and control technology and instrument technology, and specifically relates to a multimeter intelligent module with power-on alarm and self-locking functions. The housing is provided with slots of different sizes, including a limit switch slot for accommodating a limit switch, a battery slot for accommodating a battery, a circuit board slot for accommodating a single-chip microcomputer, etc., a speaker slot for accommodating a speaker, a test lead jack connected to a multimeter jack, and a multimeter slot for accommodating a multimeter body. The housing is also designed with a knob and a baffle, the knob fits with the multimeter knob, and the baffle is connected to the multimeter slot cavity to fix the multimeter; the single-chip microcomputer is respectively connected to an A / D conversion chip, a voice broadcast module, a limit switch, an indicator light, and a driver chip; the A / D conversion chip is connected to a linear regulator, the voice broadcast module is connected to a speaker, and the driver chip is connected to a relay. The present invention can avoid safety accidents caused by the test lead position not matching the selected gear, and can avoid safety hazards caused by human error.