CN205300819U - Pressure detection circuit - Google Patents

Abstract

The utility model discloses a pressure detection circuit, including pressure sensing module, signal processing module, display module and power module, power module gives pressure sensing module, signal processing module, display module power supply respectively, and pressure sensing module's output is connected with signal processing module's input, and signal processing module's output is connected with the input of display module, pressure sensing module includes pressure sensing bridge circuit and amplifier circuit, signal processing module includes the singlechip, gathers the analog signal of pressure sensing module output, after handling analog signal transmits it to the display module. The utility model discloses simple structure, low cost can satisfy the requirement of pressure sensor in sensitivity and accuracy nature simultaneously effectively.

Description

A pressure detection circuit

technical field

The utility model discloses a pressure detection circuit, which relates to the technical field of power electronics.

Background technique

Pressure sensors are widely used in industry and daily life, and can be widely used in various industrial self-control environments, such as intelligent transportation, intelligent buildings, aerospace, petrochemical, oil wells, electric power, ships, industrial production, medicine, etc. industry.

Pressure sensors are also widely used in daily life, among which strain gauge resistance pressure sensors are mainly used in pressure measurement and weighing. It converts force or pressure into strain or displacement through elastic sensitive elements, and then converts strain or displacement into electrical signals by sensors.

The resistance strain gauge is a sensitive device that converts the strain change on the tested object into an electrical signal. Usually, the strain gauge is tightly bonded to the substrate of the elastic sensitive element that produces mechanical strain through a special adhesive. When the elastic sensitive force changes in stress, the resistance strain gauge also deforms together, and its resistance value changes. In order to improve the output sensitivity, the resistance strain gauges are generally formed into a bridge circuit, and the output voltage signal is amplified by the instrument amplifier, then transmitted to the signal processing circuit, and finally transmitted to the display or actuator.

Most of the pressure detection circuits in the prior art have complicated structures, and at the same time, the sensitivity and accuracy still need to be improved.

Utility model content

The technical problem to be solved by the utility model is to provide a pressure detection circuit aiming at the defects of the prior art.

The utility model adopts the following technical solutions for solving the above-mentioned technical problems:

A pressure detection circuit, comprising a pressure sensing module, a signal processing module, a display module and a power supply module, the power supply module supplies power to the pressure sensing module, the signal processing module, and the display module respectively, and the output terminal of the pressure sensing module is connected to the signal The input terminals of the processing module are connected, and the output terminals of the signal processing module are connected with the input terminals of the display module, wherein the pressure sensing module includes a pressure sensing bridge circuit and an amplification circuit; the signal processing module includes a single-chip microcomputer, The analog signal output by the pressure sensing module is collected, processed and then transmitted to the display module.

As a further preferred solution of the present invention, the pressure sensing bridge circuit adopts a cantilever arm bridge type resistance strain gauge pressure sensor, and the resistance strain gauges on the cantilever arm form a bridge circuit;

The amplifying circuit adopts an instrument amplifying chip with 8 pins of industrial standard configuration, the power terminal and the grounding terminal of the amplifying chip are respectively connected to the power supply and the ground, and the reference terminal is connected to an external potentiometer and a reference voltage to adjust and increase the output voltage;

The non-inverting input end of the amplifying chip is connected to the positive end of the cantilever bridge type resistance strain gauge pressure sensor, and the inversion of the amplifying chip is connected to the negative end of the cantilever bridge type resistance strain gauge pressure sensor.

As a further preferred solution of the present utility model, the specific model of the single-chip microcomputer is C8051F360.

As a further preferred solution of the present invention, the display module is a liquid crystal display, and the specific model is LCD12864.

Compared with the prior art, the utility model adopts the above technical scheme and has the following technical effects: the utility model has simple structure, low cost, and can effectively meet the requirements of the pressure sensor on sensitivity and accuracy.

Description of drawings

Fig. 1 is a schematic diagram of a structural module of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are only used to explain the present invention, and cannot be construed as limiting the present invention.

Below in conjunction with accompanying drawing, the technical scheme of the utility model is described in further detail:

The structural module schematic diagram of the present utility model is as shown in Figure 1, and described pressure detection circuit comprises pressure sensing module, signal processing module, display module and power supply module, and described power supply module supplies pressure sensing module, signal processing module, The display module is powered, the output end of the pressure sensing module is connected to the input end of the signal processing module, and the output end of the signal processing module is connected to the input end of the display module, wherein the pressure sensing module includes a pressure sensing bridge circuit and amplifying circuit; the signal processing module includes a single chip microcomputer, collects the analog signal output by the pressure sensing module, processes the analog signal and transmits it to the display module.

The concrete situation of each module of the present invention is illustrated below in conjunction with specific embodiment:

Pressure sensing module: The pressure sensing bridge circuit adopts the cantilever arm bridge type resistance strain gauge pressure sensor, the resistance strain gauge on the cantilever arm forms a bridge circuit, the metal platform is the area for placing weighing objects, and the input voltage is connected to the 5V power supply voltage. The sensing circuit can output a voltage signal, which needs to be amplified by an amplifying circuit.

The amplifying circuit adopts an instrument amplifier chip with 8-pin industry standard configuration, single power supply, and can use a single gain setting resistor for gain programming, which can provide excellent AC common mode rejection ratio and keep the smallest error; when up to 200HZ, Line noise and harmonics remain constant.

When the circuit is connected, the power terminal and the ground terminal of the amplifier chip are respectively connected to the power supply and the ground, and the reference terminal is connected to an external potentiometer and a reference voltage to adjust and increase the output voltage. Connect a resistor and potentiometer in series between pin 1 and pin 8 to adjust the magnification. The noninverting input terminal of the amplifier chip is connected to the positive terminal of the bridge pressure sensor, the inverting terminal of the amplifier chip is connected to the negative terminal of the bridge pressure sensor at the input terminal, and the output terminal of the operational amplifier is connected to the signal processing module.

Signal processing module: The signal processing module adopts C8051F360 single-chip microcomputer, which integrates I2C, multiple common I/O ports, and multiple 10-bit A/D converters to collect analog signals output by pressure analog sensors. C8051F360 processes the collected signal and sends it to the Chinese liquid crystal display (LCD12864) for display, and at the same time stores the zero point measured by the pressure sensor and the calculated slope in its internal FLASH.

The power supply pin of the signal processing chip C8051F360 is connected to 3.3V, and the VSS terminal is grounded.

The output port of the pressure analog sensor is connected with the 38-pin P1.5 of the C8051F360 microcontroller to collect the pressure analog signal. The 21-pin P3.4 and 22-pin P3.3 of the C8051F360 microcontroller are respectively connected to the 5-pin LCD_SID and 6-pin LCD_SCLK of the LCD12864 to drive the display to display the processed signal.

Display module: This module is connected to the LCD screen and the signal processing module, and is used to display the data collected by the sensor and other operation prompt information. LCD12864 works in serial mode, using pins 5 and 6 to simulate I2C communication for data transmission.

Power supply module: The 12V power supply is connected to the input terminal of the voltage conversion chip LM2576, and the converted output voltage is 5V, and the LED light is used to indicate whether the 5V voltage is normal. The 5V output voltage passes through the input terminal of the voltage conversion chip AMS1117 to output 3.3V voltage.

The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings, but the present utility model is not limited to the above-mentioned embodiments. Make various changes below. The above are only preferred embodiments of the present utility model, and do not limit the utility model in any form. Although the utility model has been disclosed as above with preferred embodiments, it is not intended to limit the utility model. Any Those who are familiar with this profession, without departing from the scope of the technical solutions of the present utility model, can use the technical content disclosed above to make some changes or modify equivalent embodiments with equivalent changes, but all without departing from the technical solutions of the present utility model Solution content, according to the technical essence of the present utility model, within the spirit and principles of the present utility model, any simple modification, equivalent replacement and improvement made to the above embodiments still belong to the protection scope of the technical solution of the present utility model within.

Claims (4)

1. a pressure detection circuit, it is characterized in that: include pressure sensor block, signal processing module, display module and power module, described power module powers to respectively pressure sensor block, signal processing module, display module, the outfan of pressure sensor block is connected with the input of signal processing module, the outfan of signal processing module is connected with the input of display module, wherein

Described pressure sensor block includes pressure sensing bridge circuit and amplifying circuit;

Described signal processing module includes single-chip microcomputer, gathers the analogue signal of pressure sensor block output, transmits it to display module after analogue signal is processed.

2. a kind of pressure detection circuit as claimed in claim 1, it is characterised in that: described pressure sensing bridge circuit adopts overarm arm bridge-type resistance strain gage pressure transducer, the resistance strain gage composition bridge circuit on overarm arm;

Described amplifying circuit adopts the instrument amplification chip of 8 pin industry-standard configuration, and the power end of amplification chip and earth terminal connect power supply and ground respectively, and reference edge passes through external potentiometer and reference voltage, regulates and improves output voltage;

The in-phase input end of amplification chip accesses the anode of overarm arm bridge-type resistance strain gage pressure transducer, the anti-phase negative terminal accessing overarm arm bridge-type resistance strain gage pressure transducer of amplification chip.

3. a kind of pressure detection circuit as claimed in claim 1, it is characterised in that: the concrete model of described single-chip microcomputer is C8051F360.

4. a kind of pressure detection circuit as claimed in claim 1, it is characterised in that: described display module is liquid crystal display, and concrete model is LCD12864.