CN206353049U - A kind of intelligent electronic-scale system - Google Patents

Abstract

The utility model discloses a kind of intelligent electronic-scale system, belong to daily life technical field, including digital sampling and processing, single-chip microcomputer and liquid crystal display circuit, digital sampling and processing connects single-chip microcomputer, single-chip microcomputer connects liquid crystal display circuit, and digital sampling and processing includes sensor circuit, amplifying circuit and the change-over circuit being sequentially connected.The utility model is amplified filtering process by amplifying circuit to weak voltage signals, converted circuit becomes digital quantity and gives single-chip microcomputer again, single-chip microcomputer controls display circuit to show testee weight by liquid crystal display, the measuring precision is high, weighing is fast, convenient reading, energy-conserving and environment-protective, can work in harsh environments, overcomes the deficiencies such as not strong conditional electronic scale environmental suitability, inadequate hommization, power consumption height.

Description

A kind of intelligent electronic-scale system

Technical field

The utility model belongs to daily life technical field, is related to electronic scale direction, and in particular to a kind of intelligent electronic-scale System.

Background technology

Weighing technology is just valued by the people since ancient times, indispensable in human being's production life.Electronic scale is to weigh The product that technology is combined with electronic technology, is widely used in industrial production, commerce and trade, communications and transportation, machine-building, medicine The fields such as health, Aero-Space and scientific research.It has fast response time, simple in construction, small volume, lightweight, long lifespan The advantages of.

The content of the invention

According to above the deficiencies in the prior art, technical problem to be solved in the utility model is to propose a kind of smart electronicses Weak voltage signals are amplified filtering process by scale system by amplifying circuit, then converted circuit becomes digital quantity and given Single-chip microcomputer, single-chip microcomputer controls display circuit to show testee weight by liquid crystal display, the measuring precision is high, weighing is fast, It convenient reading, energy-conserving and environment-protective, can in harsh environments work, overcome conditional electronic scale environmental suitability not strong, not enough The deficiencies such as hommization, power consumption height.

In order to solve the above-mentioned technical problem, the technical solution adopted in the utility model is：A kind of intelligent electronic-scale system, institute Stating intelligent electronic-scale system includes digital sampling and processing, single-chip microcomputer and liquid crystal display circuit, and digital sampling and processing connects Single-chip microcomputer is connect, single-chip microcomputer connection liquid crystal display circuit, digital sampling and processing includes sensor circuit, the amplification being sequentially connected Circuit and change-over circuit, the four arm full-bridge circuits that the sensor circuit is connected using four resistance strain gages R1, R2, R3, R4, Resistance strain gage includes sensitive grid, substrate, coating and lead, and foil gauge is symmetrically pasted onto on elastic sensing element.

In said system, the amplifying circuit selects binary channels operational amplification circuit.The change-over circuit includes ADA45 cores The 7 pins connection resistance R8 of piece circuit, AD791 chip circuits and resistance R8, ADA45 chip one end, the resistance R8 other end Connect 4 pins of AD791 chips.The ADA45 chip circuits include resistance R1, R2, R3, R4, R5, R6, R7, R8, Rg and electricity Hold AD791 chips in C1, C2, resistance R1, R2, R3 and R4 series connection, resistance R1 and R3 tie point connection AD791 chip circuits 5 pins, resistance R2 and R4 tie point connects 6 pins of AD791 chips, resistance R3 and R4 tie point connection ADA45 chips 3 pins, resistance R1 and R2 tie point connects 5 pins of ADA45 chips, the 2 pins connection resistance R5 and electricity of ADA45 chips Rg is hindered, the resistance R5 other end is by resistance R7 connection AD791 chip circuits, and resistance R5 two ends are parallel with electric capacity C1, resistance The Rg other end passes through resistance R6 and R8 connection AD791 chip circuits, resistance R6 two ends shunt capacitance C2.The AD791 cores Piece circuit include resistance R9, R10, R11, R12, the 1 of electric capacity C3, C4, C6, C7, C9, C10 and converting interface P1, converting interface P1,2, 3 and 4 pins are connected to 2,1,10 and 9 pins of AD791 chips by resistance R9, R10, R11 and R12 respectively, AD791 chips 3 and 4 pins connect electric capacity C3 and C4 respectively, while ADA45 chip circuits are connected, the 5 pins connection electric capacity C9 of ADA45 chips, C10 and ADA45 chip circuits, the electric capacity C10 other end connects 6 pins of AD791 chips, and AD791 chips obtain 8 pins difference Connect electric capacity C6 and C7.

The utility model beneficial effect is:The intelligent electronic-scale system that the utility model is provided, utilizes high sensitivity resistance Strain gauge transducer realizes weight of object information gathering, and small-signal is amplified by high-gain, low drifting instrumentation amplifier and adjusted Reason, digital output is realized using 24 sigma-delta pattern number converters, controls liquid crystal display to show measurement knot in real time by single-chip microcomputer Really.The electronic balance structure is simple, and measurement accuracy is high, weighing speed is fast, convenient reading, energy-conserving and environment-protective, more humane, with wide Application prospect and promotional value.

Brief description of the drawings

The mark in the content and figure expressed by this specification accompanying drawing is briefly described below：

Fig. 1 is the operation principle block diagram of the intelligent electronic-scale system of embodiment of the present utility model.

Fig. 2 is the structural representation of the resistance strain gage of embodiment of the present utility model.

Fig. 3 is the circuit diagram of four arm full-bridge circuits of embodiment of the present utility model.

Fig. 4 is the circuit diagram of the change-over circuit of embodiment of the present utility model.

Wherein, 1- substrates, 2- sensitive grids, 3- leads, 4- coatings.

Embodiment

Below against accompanying drawing, by the description to embodiment, embodiment of the present utility model is for example involved each Mutual alignment and annexation, the effect of each several part and operation principle, manufacture work between the shape of component, construction, each several part Skill and operate with method etc., are described in further detail, to help those skilled in the art to invention of the present utility model Design, technical scheme have more complete, accurate and deep understanding.

As Figure 1-4, a kind of intelligent electronic-scale system, including digital sampling and processing, single-chip microcomputer and liquid crystal display Circuit, digital sampling and processing connection single-chip microcomputer, single-chip microcomputer connection liquid crystal display circuit, digital sampling and processing include according to Sensor circuit, amplifying circuit and the change-over circuit of secondary connection, the sensor circuit using four resistance strain gage R1, R2, Four arm full-bridge circuits of R3, R4 connection, resistance strain gage includes sensitive grid, substrate, coating and lead, and substrate is fixed on sensitivity On grid, lead connection substrate, it is sensitive that coating is located at covering above substrate.Foil gauge is symmetrically pasted onto on elastic sensing element, When weight is put on electronic scale, the analog voltage signal that sensor circuit output is directly proportional to weight of object, by amplifying electricity Weak voltage signals are amplified on road, are then passed to A/D change-over circuits and carry out analog-to-digital conversion (A/D conversions), then by the number after conversion Word amount gives single-chip microcomputer, and single-chip microcomputer receives after data, data are handled, is converted and passes through liquid crystal as quality information Show that circuit is shown.

Sensor circuit uses the resistance strain gage of low-cost and high-precision, and the sensor performance decides whole electronic scale Precision, is one of core component of electronic scale.R1, R2, R3, R4 are resistance strain gage in figure, can with choice accuracy grade compared with High same gauge metal foil gauge, such as BF350-3AA models constantan foil metal strain plate, its accuracy class are 0.02 grade, Initial resistance is 350 Ω, and strain limit 2.0%, temperature range is -30 DEG C -150 DEG C.Why four arm full-bridge circuits are used, Mainly consider that full-bridge differential circuit sensitivity is higher, can carry out temperature-compensating, without nonlinearity erron.Four arm full-bridges The faint resistance variations that resistance strain gage is sent out are converted to voltage change by circuit, without nonlinearity erron, because electric bridge is defeated Go out voltage signal fainter, usually millivolt level even microvolt level, it is impossible to which meeting A/D converter will to signal incoming level Ask, it is therefore desirable to which the accurate instrumentation amplifier of selection, to obtain sufficiently high gain, improves signal amplitude as frontend amplifying circuit. Selection ADA4528-2 is binary channels operational amplification circuit herein, and it has 2.2V to 5.5V wide working power voltage scope, height Gain, outstanding CMRR and PSRR characteristics.Offset voltage is 2.5uV, and offset voltage drift is 0.015uV/ DEG C, is particularly suitable for use in Low level precision amplification, 8 pin packages are illustrated continuous according to pin when using, can powered using battery, by reasonable Feedback resistance, electric capacity, composition low pass filter limitation noise are set.

7 pins that change-over circuit includes ADA45 chip circuits, AD791 chip circuits and resistance R8, ADA45 chip are connected Resistance R8 one end, the resistance R8 other end connects 4 pins of AD791 chips.The ADA45 chip circuits include resistance R1, R2, R3, R4, R5, R6, R7, R8, Rg and electric capacity C1, C2, resistance R1, R2, R3 and R4 series connection, resistance R1 and R3 tie point connect 5 pins of AD791 chips in AD791 chip circuits are connect, resistance R2 and R4 tie point connect 6 pins of AD791 chips, resistance R3 and R4 tie point connects 3 pins of ADA45 chips, and resistance R1 and R2 tie point connect 5 pins of ADA45 chips, ADA45 chips 2 pins connection resistance R5 and resistance Rg, the resistance R5 other end by resistance R7 connection AD791 chip circuits, Resistance R5 two ends are parallel with electric capacity C1, and the resistance Rg other end passes through resistance R6 and R8 connection AD791 chip circuits, resistance R6 Two ends shunt capacitance C2.The AD791 chip circuits include resistance R9, R10, R11, R12, electric capacity C3, C4, C6, C7, C9, C10 and converting interface P1, converting interface P1 1,2,3 and 4 pins are connected to AD791 cores by resistance R9, R10, R11 and R12 respectively 2,1,10 and 9 pins of piece, 3 and 4 pins of AD791 chips connect electric capacity C3 and C4 respectively, while connecting ADA45 chips electricity Road, 5 pins connection electric capacity C9, C10 and ADA45 chip circuit of ADA45 chips, electric capacity C10 other end connection AD791 chips 6 pins, AD791 chips obtain 8 pins and connect electric capacity C6 and C7 respectively.As illustrated, R1, R2, R3, R4 are resistance-strains Piece, same model specification, weight is pressed onto on elastic sensing element during measurement, and elastic sensing element deforms, and is attached to thereon Foil gauge deform therewith, represented with variation delta, cause resistance to change, by electric bridge, change output voltage.

A/D change-over circuits are the conversions for realizing analog signal to data signal, and voltage signal sampling coding output is given Control module.In order to realize high-precision conversion, sigma-delta type ADC chips can be selected.According to electronic scale measurement range and precision It is required that, select AD7791 chips, its built-in 24 sigma-delta type ADC, wherein containing an available buffer or defeated without buffering difference Enter, be internally integrated a differential input amplifier circuit, the circuit can carry out secondary singal amplification.AD7791 receives difference Simulation input and differential reference voltage, to be adapted to low-power consumption, the full simulation front end of low frequency measurement application, during using 3V power supplys, The typical power consumption of the two is 65 μ A；During using 5V power supplys, disabling buffering, typical power consumption is 75 μ A.On the whole, it can meet faint Signal transacting, precision are high, interface is simple, low in energy consumption.

Single-chip microcomputer selects STC89C52 chips, with small volume, low in energy consumption, control function be strong, extension flexibly, miniaturization and Easy to use the advantages of, it is widely used in instrument and meter.STC89C52 is a kind of low-power consumption, 8 microcontrollers of high-performance CMOS Device, it is cheap with 8K in-system programmable components flash storages, it disclosure satisfy that electronic scale demand.What the utility model was provided A kind of intelligent electronic-scale system based on resistance strain type sensor, its small volume, lightweight, low in energy consumption, accurate measurement, reading Intuitively, it is easy to carry, people's daily life can be met to the demand weighed.

The utility model is exemplarily described above in conjunction with accompanying drawing, it is clear that the utility model implement not by The limitation of aforesaid way, as long as employing changing for the various unsubstantialities that method design of the present utility model and technical scheme are carried out Enter, or it is not improved by it is of the present utility model design and technical scheme directly apply to other occasions, in the utility model Protection domain within.Protection domain of the present utility model should be determined by the scope of protection defined in the claims.

Claims (5)

1. a kind of intelligent electronic-scale system, it is characterised in that the intelligent electronic-scale system includes digital sampling and processing, list Piece machine and liquid crystal display circuit, digital sampling and processing connection single-chip microcomputer, single-chip microcomputer connection liquid crystal display circuit, data acquisition Processing module includes sensor circuit, amplifying circuit and the change-over circuit being sequentially connected, and the sensor circuit is using four electricity Four arm full-bridge circuits of foil gauge R1, R2, R3, R4 connection are hindered, resistance strain gage includes sensitive grid, substrate, coating and lead, Foil gauge is symmetrically pasted onto on elastic sensing element.

2. intelligent electronic-scale system according to claim 1, it is characterised in that the amplifying circuit selects binary channels computing Amplifying circuit.

3. intelligent electronic-scale system according to claim 1, it is characterised in that the change-over circuit includes ADA45 chips The 7 pins connection resistance R8 of circuit, AD791 chip circuits and resistance R8, ADA45 chip one end, the resistance R8 other end connects Connect 4 pins of AD791 chips.

4. intelligent electronic-scale system according to claim 3, it is characterised in that the ADA45 chip circuits include resistance R1, R2, R3, R4, R5, R6, R7, R8, Rg and electric capacity C1, C2, resistance R1, R2, R3 and R4 series connection, resistance R1 and R3 tie point 5 pins of AD791 chips in AD791 chip circuits are connected, resistance R2 and R4 tie point connect 6 pins of AD791 chips, electricity The tie point for hindering R3 and R4 connects 3 pins of ADA45 chips, and resistance R1 and R2 tie point connect 5 pins of ADA45 chips, ADA45 chips 2 pins connection resistance R5 and resistance Rg, the resistance R5 other end by resistance R7 connection AD791 chip circuits, Resistance R5 two ends are parallel with electric capacity C1, and the resistance Rg other end passes through resistance R6 and R8 connection AD791 chip circuits, resistance R6 Two ends shunt capacitance C2.

5. intelligent electronic-scale system according to claim 3, it is characterised in that the AD791 chip circuits include resistance R9, R10, R11, R12, electric capacity C3, C4, C6, C7, C9, C10 and converting interface P1, converting interface P1 1,2,3 and 4 pins lead to respectively 2,1,10 and 9 pins that resistance R9, R10, R11 and R12 are connected to AD791 chips are crossed, 3 and 4 pins of AD791 chips connect respectively Electric capacity C3 and C4 are met, while ADA45 chip circuits are connected, 5 pins connection electric capacity C9, C10 and ADA45 chip of ADA45 chips Circuit, the electric capacity C10 other end connects 6 pins of AD791 chips, and AD791 chips obtain 8 pins and connect electric capacity C6 and C7 respectively.