CN216668834U

CN216668834U - Electromagnetic flowmeter

Info

Publication number: CN216668834U
Application number: CN202122466539.4U
Authority: CN
Inventors: 范守鑫; 葛利军
Original assignee: Kaifeng Jingbo Automation Instrument Co ltd
Current assignee: Kaifeng Jingbo Automation Instrument Co ltd
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2022-06-03
Anticipated expiration: 2031-10-13

Abstract

The utility model discloses an electromagnetic flowmeter, which comprises a flow monitoring unit and a display unit, wherein the flow monitoring unit comprises an electromagnetic flow sensor, an amplitude stabilizing circuit and a differential amplification noise reduction circuit, the display unit comprises a controller and an electronic display which are connected through a data bus, the electromagnetic flowmeter detects the flow of fluid in a pipeline through the electromagnetic flow sensor, a detection signal is firstly sent into the amplitude stabilizing circuit to be processed, the good temperature characteristic of an MOS (metal oxide semiconductor) tube is utilized to play a good improvement role in the waveform of the detection signal, the stability of amplification output of the detection signal is ensured, and the fluctuation of the signal output is avoided; the differential amplification noise reduction circuit effectively eliminates common-mode interference by adopting a differential amplifier principle, improves the amplification precision of detection signals, and adopts an RC filter to carry out filtering noise reduction processing on output signals of the differential amplifier, thereby greatly improving the anti-interference capability and the detection precision of the flowmeter.

Description

Electromagnetic flowmeter

Technical Field

The utility model relates to the technical field of flow meters, in particular to an electromagnetic flow meter.

Background

The structure of the electromagnetic flowmeter mainly comprises a magnetic circuit system, a measuring conduit, an electrode, a shell, a lining, a converter and the like. Generally, if the cable between the sensor and the transducer is long and there is strong electromagnetic interference around the cable, the cable may introduce interference signals, form common mode interference, cause display distortion, nonlinearity or large amplitude jitter, and thus seriously affect the detection accuracy of the electromagnetic flowmeter.

The present invention provides a new solution to this problem.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is an object of the present invention to provide an electromagnetic flowmeter that overcomes the drawbacks of the prior art.

The technical scheme for solving the problem is as follows: the utility model provides an electromagnetic flowmeter, includes flow monitoring unit and display element, the flow monitoring unit includes that electromagnetic flow sensor, steady amplitude circuit and difference amplify and fall the circuit of making an uproar, the display element includes controller and the electronic display who connects through data bus, electromagnetic flow sensor's signal output part connects the input of steady amplitude circuit, the output of steady amplitude circuit is connected the input of the circuit of making an uproar falls in the difference amplification, the output of the circuit of making an uproar falls in the difference amplification is connected the controller.

Preferably, the amplitude stabilizing circuit comprises a MOS transistor Q1, a drain of the MOS transistor Q1 is connected to one end of a capacitor C1 and a signal output end of the electromagnetic flow sensor through a resistor R1, and is connected to a gate of the MOS transistor Q1 and a cathode of a zener diode DZ1 through a resistor R2, the other end of the capacitor C1 is grounded, and an anode of the zener diode DZ1 is grounded.

Preferably, the differential amplification noise reduction circuit comprises an operational amplifier AR1 and an operational amplifier AR2, a non-inverting input terminal of the operational amplifier AR1 is connected to the source of the MOS transistor Q1 and one end of the resistors R4 and R5, the other end of the resistor R4 is grounded, the other end of the resistor R5 is connected to the non-inverting input terminal of the operational amplifier AR2, an inverting input terminal of the operational amplifier AR1 is grounded through the resistor R3 and is connected to the output terminal of the operational amplifier AR1 and one end of the resistors R8 and C3 through the capacitor C2, the inverting input terminal of the operational amplifier AR2 is grounded through the resistor R6 and is connected to the output terminal of the operational amplifier AR2 through the resistor R7, the output terminal of the operational amplifier AR2 is connected to the other end of the resistor R8 and one end of the capacitor C4, and the other ends of the capacitors C3 and C4 are connected to the controller and are grounded through the resistor R9.

Preferably, the device further comprises a WiFi module, and the WiFi module is connected with the controller through a serial port.

Through the technical scheme, the utility model has the beneficial effects that:

1. the electromagnetic flow sensor is used for detecting the flow of fluid in a pipeline, a detection signal of the electromagnetic flow sensor is firstly sent into the amplitude stabilizing circuit for processing, the good temperature characteristic of the MOS tube is utilized to play a good role in improving the waveform of the detection signal, the stability of the amplification output of the detection signal is ensured, and the fluctuation of the signal output is avoided;

2. the differential amplification noise reduction circuit effectively eliminates common-mode interference by adopting a differential amplifier principle, improves the amplification precision of detection signals, and adopts an RC filter to carry out filtering noise reduction processing on output signals of the differential amplifier, thereby greatly improving the anti-interference capability and the detection precision of the flowmeter.

Drawings

Fig. 1 is a schematic circuit diagram of a flow monitoring unit of the present invention.

Detailed Description

The foregoing and other technical and scientific aspects, features and utilities of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings of fig. 1. The structural contents mentioned in the following embodiments are all referred to the attached drawings of the specification.

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

The utility model provides an electromagnetic flowmeter, includes flow monitoring unit and display element, the flow monitoring unit includes that electromagnetic flow sensor, steady amplitude circuit and difference amplify and fall the circuit of making an uproar, the display element includes controller and the electronic display who connects through data bus, electromagnetic flow sensor's signal output part connects the input of steady amplitude circuit, the output of steady amplitude circuit is connected the input of the circuit of making an uproar falls in the difference amplification, the output of the circuit of making an uproar falls in the difference amplification is connected the controller.

As shown in fig. 1, the amplitude stabilizing circuit includes a MOS transistor Q1, a drain of the MOS transistor Q1 is connected to one end of a capacitor C1 and a signal output end of the electromagnetic flow sensor through a resistor R1, and is connected to a gate of the MOS transistor Q1 and a cathode of a zener diode DZ1 through a resistor R2, the other end of the capacitor C1 is grounded, and an anode of the zener diode DZ1 is grounded.

The differential amplification noise reduction circuit comprises an operational amplifier AR1 and an AR2, wherein the non-inverting input end of an operational amplifier AR1 is connected with the source of a MOS transistor Q1 and one end of a resistor R4 and one end of a resistor R5, the other end of the resistor R4 is grounded, the other end of a resistor R5 is connected with the non-inverting input end of the operational amplifier AR2, the inverting input end of the operational amplifier AR1 is grounded through a resistor R3 and is connected with the output end of an operational amplifier AR1 and one end of a resistor R8 and a capacitor C3 through a capacitor C2, the inverting input end of the operational amplifier AR2 is grounded through a resistor R6 and is connected with the output end of an operational amplifier AR2 through a resistor R7, the output end of the operational amplifier AR2 is connected with the other end of a resistor R8 and one end of a capacitor C4, and the other ends of capacitors C3 and C4 are connected with the controller and are grounded through a resistor R9.

When the electromagnetic flow sensor is used specifically, the electromagnetic flow sensor detects the flow of fluid in a pipeline, and in order to avoid external electromagnetic interference, detection signals are sequentially sent to the amplitude stabilizing circuit and the differential amplification noise reduction circuit to be processed. The specific principle is as follows: firstly, the amplitude stabilizing circuit adopts a capacitor C1 to filter a detection signal and then sends the detection signal into a MOS tube Q1 for amplification, the good temperature characteristic of the MOS tube is utilized to play a good improving role in the waveform of the detection signal, and a voltage stabilizing diode DZ1 is utilized to benchmark the grid voltage of the MOS tube Q1, so that the stability of the amplification output of the detection signal is ensured, and the fluctuation of the signal output is avoided.

Because the detection signal has common-mode interference in the processing process, the differential amplifier composed of the operational amplifiers AR1 and AR2 is adopted in the differential amplification noise reduction circuit to amplify the output signal of the MOS transistor Q1, so that the common-mode interference is effectively eliminated, and the amplification precision of the detection signal is improved. And the RC filter consisting of the capacitors C3 and C4 and the resistors R8 and R9 is adopted to filter and reduce noise of the output signals of the differential amplifier, so that the anti-interference capability of the flowmeter is greatly improved. The controller analyzes and processes the output signal of the differential amplification noise reduction circuit, calculates the real-time flow of the fluid, and then sends the fluid into the electronic display for display. When the intelligent flow meter is specifically set, the WiFi module is further arranged on the electromagnetic flow meter and is connected with the controller through a serial port, and the flow data calculated by the controller are remotely transmitted to the user terminal, so that the user can check the flow data conveniently and timely.

While the utility model has been described in further detail with reference to specific embodiments thereof, it is not intended that the utility model be limited to the specific embodiments thereof; for those skilled in the art to which the present invention pertains and related technologies, the extension, operation method and data replacement should fall within the protection scope of the present invention based on the technical solution of the present invention.

Claims

1. The utility model provides an electromagnetic flowmeter, includes flow monitoring unit and display element, its characterized in that: the flow monitoring unit comprises an electromagnetic flow sensor, an amplitude stabilizing circuit and a differential amplification noise reduction circuit, the display unit comprises a controller and an electronic display which are connected through a data bus, the signal output end of the electromagnetic flow sensor is connected with the input end of the amplitude stabilizing circuit, the output end of the amplitude stabilizing circuit is connected with the input end of the differential amplification noise reduction circuit, and the output end of the differential amplification noise reduction circuit is connected with the controller.

2. An electromagnetic flowmeter as set forth in claim 1 wherein: the amplitude stabilizing circuit comprises a MOS tube Q1, the drain electrode of the MOS tube Q1 is connected with one end of a capacitor C1 and the signal output end of the electromagnetic flow sensor through a resistor R1, and is connected with the grid electrode of a MOS tube Q1 and the cathode of a voltage stabilizing diode DZ1 through a resistor R2, the other end of the capacitor C1 is grounded, and the anode of the voltage stabilizing diode DZ1 is grounded.

3. An electromagnetic flow meter according to claim 2, characterized in that: the differential amplification noise reduction circuit comprises an operational amplifier AR1 and an AR2, wherein the non-inverting input end of an operational amplifier AR1 is connected with the source of a MOS transistor Q1 and one end of a resistor R4 and one end of a resistor R5, the other end of the resistor R4 is grounded, the other end of a resistor R5 is connected with the non-inverting input end of the operational amplifier AR2, the inverting input end of the operational amplifier AR1 is grounded through a resistor R3 and is connected with the output end of an operational amplifier AR1 and one end of a resistor R8 and a capacitor C3 through a capacitor C2, the inverting input end of the operational amplifier AR2 is grounded through a resistor R6 and is connected with the output end of an operational amplifier AR2 through a resistor R7, the output end of the operational amplifier AR2 is connected with the other end of a resistor R8 and one end of a capacitor C4, and the other ends of capacitors C3 and C4 are connected with the controller and are grounded through a resistor R9.

4. An electromagnetic flow meter according to any of claims 1-3, characterized in that: the WiFi module is connected with the controller through a serial port.