CN205483103U

CN205483103U - Electromagnetic flow converter

Info

Publication number: CN205483103U
Application number: CN201521135540.7U
Authority: CN
Inventors: 蒲诚; 孙靖; 杜亮
Original assignee: Tianjin Sure Automation Control Equipment Manufacturing Co ltd
Current assignee: Tianjin Sure Automation Control Equipment Manufacturing Co ltd
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2016-08-17
Anticipated expiration: 2025-12-30

Abstract

The utility model belongs to the technical field of flow measurement, especially, relate to an electromagnetic flow converter, including flow analog signal, conductivity analog signal, digital analog converter and MCU treater, flow analog signal is connected with digital analog converter's passageway 1, and conductivity analog signal is connected with digital analog converter's passageway 0, and digital analog converter is connected with the MCU treater, and digital analog converter adopts MCP3901 chip, and the MCU treater reads digital analog converter data through the SPI interface. The utility model has the advantages that: the digital-to-analog converter adopts an MCP3901 chip, is convenient and easy to obtain, has double channels, and separates the conductivity analog signal and the flow analog signal on the space while ensuring the sampling precision through 24-bit resolution A/D conversion; the independent clock system ensures synchronous and discrete operation.

Description

A kind of electromagnetic flux converter

Technical field

This utility model belongs to flow measurement technology field, particularly relates to a kind of electromagnetic flux converter.

Background technology

Electromagnetic flowmeter survey electrode exposed in atmosphere time, sensor can produce stronger interference signal, cause flow simulation The serious distortion of signal, therefore electromagnetic flowmeter in use requires that fluid is full of whole pipeline, but in actual application, It is difficult to ensure that pipe full fluid.Now, the conventional method measuring electrical conductivity detects whether pipeline is in empty pipe condition.

Gather electrical conductivity analogue signal now and current signal commonly uses two kinds of methods.One is that electrical switch controls sampling time sequence, Use V/F conversion chip (such as AD652) that the sampled signal of the two is changed.This method of sampling needs higher system Frequency, sampling channel needs time-sharing multiplex, and sampling efficiency is low, and electrical switch needs high current support simultaneously, and power consumption is big. Another kind of method is that the two-way A/D conversion utilizing MCU gathers signal, though this method is simple, convenient, but Chip Microcomputer A/D Conversion mostly is 12 bit resolution conversions passages, it is impossible to ensure precision.

Utility model content

For the problems referred to above to be solved, this utility model provides a kind of electromagnetic flux converter.

To achieve these goals, this utility model provides a kind of electromagnetic flux converter, including electrical conductivity analogue signal, stream Amount analogue signal, digital to analog converter and the passage 0 of MCU processor, described electrical conductivity analogue signal and described digital to analog converter Connecting, described flow analog signals is connected with the passage 1 of described digital to analog converter, at described digital to analog converter and described MCU Reason device connects, and described digital to analog converter uses MCP3901 chip, and described MCU processor reads described number by SPI interface Weighted-voltage D/A converter data.

Described digital to analog converter uses the MCP3901 chip, the described MCP3901 chip 2 pin number power supply DVDD that powers to be 3.3V, described MCP3901 chip 3 pin analog power is powered as 5V, the described electrical conductivity analogue signal described MCP3901 of input The input pin CH0+ of simulation in the same direction of chip 4 pin passage 0, described flow analog signals inputs 7 pin passages 1 in the same direction Simulation input pin CH1+, the pin CH0-of described MCP3901 chip and pin CH0+ ground connection, described MCP3901 chip 9 Pin Refin+ and 10 pin Refin-ground connection, connect between the 9 pin Refin+ and 9 pin AGND of described MCP3901 chip Meet electric capacity C₆With electric capacity C₄, electric capacity C₆For the ceramic condenser of 0.1uF, electric capacity C₄Tantalum electric capacity for 10uF.

Described MCU processor uses MSP430F2272 chip, and the pin DVCC of described MSP430F2272 chip meets 3.3V Power supply, when 9 pin P2.1 of described P430F2272 chip connect 15 pin OSC1 input outside of described MCP3901 chip Clock, it is serial that 8 pin P2.0 of described MSP430F2272 chip meet the 17 pins/CS of described MCP3901 chip ,/CS Interface chip selects, and 10 pins 2.2 of described MSP430F2272 chip meet described MCP3901 chip 14 pins/DR ,/DR and are Data ready output pin, described MSP430F2272 chip 14 pin P3.3,13 pin P3.2,12 pin P3.1 divide Do not connect described MCP3901 chip 18 pin, 20 pins, 19 pin serial SPI interface clock and data pin.This practicality Novel providing the benefit that: digital to analog converter uses MCP3901 chip, MCP3901 chip is widely used in ammeter and power is surveyed Amount, buying is convenient easily to be obtained, and price is the most relatively cheap；The dual pathways, 24 bit resolution A/D conversions ensure the same of sampling precision Time electrical conductivity analogue signal and flow analog signals are spatially separated from；Independent clock system ensure to use synchronize, discrete Carry out；SPI interface provides greater flexibility for engineers design, can be by the over-sampling rate of the positive ADC that makes pottery, needed for control Resolution and sample rate.

Accompanying drawing explanation

Fig. 1 is structured flowchart of the present utility model.

Fig. 2 is the circuit diagram of digital to analog converter of the present utility model.

Fig. 3 is the circuit diagram of MCU processor of the present utility model

Detailed description of the invention

Below in conjunction with the accompanying drawings a kind of detailed description of the invention of utility model is explained.

This utility model provides a kind of electromagnetic flux converter, turns including electrical conductivity analogue signal, flow analog signals, digital-to-analogue Parallel operation and MCU processor, electrical conductivity analogue signal is connected with the passage 0 of digital to analog converter, and flow analog signals turns with digital-to-analogue The passage 1 of parallel operation connects, and digital to analog converter is connected with MCU processor, and digital to analog converter uses MCP3901 chip, at MCU Reason device reads digital to analog converter data by SPI interface, and digital to analog converter uses MCP3901 chip, and MCP3901 chip is universal Being applied to ammeter and power measurement, buying is convenient easily to be obtained, and price is the most relatively cheap；The dual pathways, 24 bit resolution A/D turn While changing guarantee sampling precision, electrical conductivity analogue signal and flow analog signals are spatially separated from；Independent clock system Ensure to use and synchronize, discrete carry out；SPI interface provides greater flexibility for engineers design, can be by the mistake of the positive ADC that makes pottery Sample rate, the resolution needed for control and sample rate.

Digital to analog converter uses MCP3901 chip, and the MCP3901 chip 2 foot digital power DVDD that powers is 3.3V, MCP3901 Chip 3 foot analog power is powered as 5V, and electrical conductivity analogue signal inputs the input pin CH0+ of simulation in the same direction of 4 foot passages 0, Flow analog signals inputs the input pin CH1+ of simulation in the same direction of 7 foot passages 1, the pin CH0-of MCP3901 chip and pin CH0+ ground connection, enables internal reference voltage, MCP3901 chip 9 foot Refin+ and 10 foot Refin-ground connection, MCP3901 core Electric capacity C is connected between the 9 foot Refin+ and 9 foot AGND of sheet₆With electric capacity C₄, electric capacity C₆For the ceramic condenser of 0.1uF, electric capacity C₄For the tantalum electric capacity of 10uF, prevent noise from producing aliasing in conversion data, reach ADC maximal accuracy.

MCU processor uses low-power consumption MSP430F2272 chip, and the pin DVCC of MSP430F2272 chip connects 3.3V power supply, The 2.1 of P430F2272 chip meet the pin 15OSC1 of MCP3901 chip and input external clock, by MCLK system sub-clock Thering is provided the AD external clock of sampling, the P2.0 of MSP430F2272 chip meets the 17 feet/CS of MCP3901 chip, and/CS is string Line interface sheet select, MSP430F2272 chip 2.2 connect MCP3901 chip pin 14/DR ,/DR be data ready output Pin, MSP430F2272 chip P3.3, P3.2, P3.1 meet MCP3901 chip P18, P20, P19 serial SPI respectively Interface clock and data pin, processed by internal calculation and obtain instantaneous delivery, be shown on meter interface.

Compared with prior art, digital to analog converter uses MCP3901 chip, and MCP3901 chip is widely used in ammeter and power Measuring, buying is convenient easily to be obtained, and price is the most relatively cheap；The dual pathways of digital to analog converter, 24 bit resolution A/D conversions are protected While card sampling precision, electrical conductivity analogue signal and flow analog signals are spatially separated from；Independent clock system ensures Use and synchronize, discrete carry out；SPI interface provides greater flexibility for engineers design, can be by the over-sampling of the positive ADC that makes pottery Rate, the resolution needed for control and sample rate.

The above-mentioned equal buyable of all elements obtains, and the pin connected mode of chip is conventional connected mode, does not describes in detail at this.

Above example of the present utility model is described in detail, but described content has been only preferable enforcement of the present utility model Example, it is impossible to be considered for limiting practical range of the present utility model.All impartial changes made according to this utility model application range Change and improvement etc., within all should still belonging to patent covering scope of the present utility model.

Claims

1. an electromagnetic flux converter, at electrical conductivity analogue signal, flow analog signals, digital to analog converter and MCU Reason device, described electrical conductivity analogue signal is connected with the passage 0 of described digital to analog converter, described flow analog signals and described number The passage 1 of weighted-voltage D/A converter connects, and described digital to analog converter is connected with described MCU processor, and described digital to analog converter uses MCP3901 chip, described MCU processor reads described digital to analog converter data by SPI interface.

A kind of electromagnetic flux converter the most according to claim 1, it is characterised in that described digital to analog converter uses MCP3901 chip, the described MCP3901 chip 2 pin number power supply DVDD that powers is 3.3V, described MCP3901 chip 3 Pin analog power is powered as 5V, and described electrical conductivity analogue signal inputs described MCP3901 chip 4 pin passage 0 in the same direction Simulation input pin CH0+, described flow analog signals inputs the input pin CH1+ of simulation in the same direction of 7 pin passages 1, described The pin CH0-of MCP3901 chip and pin CH0+ ground connection, described MCP3901 chip 9 pin Refin+ and 10 pin Refin- Ground connection, connects electric capacity C between the 9 pin Refin+ and 9 pin AGND of described MCP3901 chip₆With electric capacity C₄, electric capacity C₆ For the ceramic condenser of 0.1uF, electric capacity C₄Tantalum electric capacity for 10uF.

3. according to a kind of electromagnetic flux converter described in claim 1, it is characterised in that described MCU processor uses MSP430F2272 chip, the pin DVCC of described MSP430F2272 chip connects 3.3V power supply, described P430F2272 chip 9 pin P2.1 connect described MCP3901 chip 15 pin OSC1 input external clocks, described MSP430F2272 chip 8 pin P2.0 to meet the 17 pins/CS ,/CS of described MCP3901 chip be the choosing of serial line interface sheet, described MSP430F2272 It is data ready output pin that 10 pins 2.2 of chip meet described MCP3901 chip 14 pins/DR ,/DR, described MSP430F2272 chip 14 pin P3.3,13 pin P3.2,12 pin P3.1 connect described MCP3901 chip 18 respectively Pin, 20 pins, 19 pin serial SPI interface clock and data pin.