CN205038006U - Pressure collecting circuit of constant current source driving pressure sensor - Google Patents
Pressure collecting circuit of constant current source driving pressure sensor Download PDFInfo
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- CN205038006U CN205038006U CN201520777189.5U CN201520777189U CN205038006U CN 205038006 U CN205038006 U CN 205038006U CN 201520777189 U CN201520777189 U CN 201520777189U CN 205038006 U CN205038006 U CN 205038006U
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Abstract
The utility model discloses a pressure collecting circuit of constant current source driving pressure sensor, its characterized in that: including power supply, constant -current source circuit, pressure sensor, signal amplification circuit, AD converter and MCU, the constant -current source circuit is used for driving pressure sensor, pressure sensors output and pressure become linear relation's voltage signal, this voltage signal warp signal amplification circuit enlargies the back, and the transmission is given the AD converter, after the AD converter converts the voltage signal of simulation to discrete data signal, this discrete data signal through the SPI interface transmit for MCU, power supply provides the power for this pressure collecting circuit. Beneficial effect: simple structure effectively reduces the precision of pressure sensor circuit because of temperature data collection, pressure sensor supply circuit avoids causing the great problem of data collection error because of being undulant.
Description
Technical field
The utility model relates to pressure sensor application technical field, specifically, is a kind of pressure acquisition circuit of constant current source driving pressure sensor.
Background technology
The application of pressure transducer is very extensive, and almost penetrated into all trades and professions, the output voltage signal temperature influence of piezoresistive pressure sensor, the fluid flow pressure data precision causing pressure transducer to gather is poor.For solving the problem of temperature influence when pressure transducer works, people are addressed this problem by the mode using constant current source to power for pressure transducer usually.But the pressure transducer pressure acquisition circuit of existing constant current source power supply still cannot meet the requirements for high precision that pressure transducer gathers pressure data, and power consumption is higher.
Utility model content
In view of this, the utility model provides a kind of pressure acquisition circuit of constant current source driving pressure sensor, and the mode adopting constant current source to drive makes system can export the voltage signal linear with pressure.
Concrete technical scheme is as follows:
A pressure acquisition circuit for constant current source driving pressure sensor, its key is: comprise power supply, constant-current source circuit, pressure transducer, signal amplification circuit, A/D converter and MCU; The input end of pressure transducer described in the output termination of described constant-current source circuit, in order to drive described pressure transducer, described pressure transducer exports the voltage signal linear with pressure, signal amplification circuit described in the output termination of described pressure transducer, described signal amplification circuit passes to described A/D converter after being amplified by this voltage signal, after described A/D converter converts the voltage signal of simulation to discrete digital signal, this discrete digital signal passes to described MCU through SPI interface, and described power supply provides power supply for this pressure acquisition circuit.
Based on the pressure acquisition circuit of the constant current source driving pressure sensor of said structure, constant-current source circuit is as the driving circuit of described pressure transducer, described pressure transducer exports the weak voltage signals linear with pressure, this weak voltage signals, after signal amplification circuit amplifies, converts discrete signal to for described MCU process by described A/D converter.
The utility model uses the formal construction constant-current source circuit of comparer Q1 and triode Q3, and described triode Q3 adopts PNP type triode; Forward end ground connection after resistance R5 of described comparer Q1, and the IN-of pressure transducer described in the forward termination of described comparer Q1 holds; The negative end of described comparer Q1 meets power supply VCC successively after resistance R3, resistance R2, the negative end also ground connection after resistance R4 of described comparer Q1, described resistance R4 two ends shunt capacitance C4; The output terminal of described comparer Q1 connects the base stage of described triode Q3 through resistance R6, the emitter of described triode Q3 meets described power supply VCC, the collector of described triode Q3 connects the IN+ end of described pressure transducer, and flying capcitor C5 between the collector of described triode Q3 and base stage.
Further, for strengthening the weak voltage signals that described pressure transducer exports, adopt the two-stage signal amplifying circuit be made up of operational amplifier Q4 and operational amplifier Q5, the OUT-end of the pressure transducer described in termination in the same way of described operational amplifier Q4, the OUT-end also ground connection after electric capacity C7 of described pressure transducer, and the end in the same way of described operational amplifier Q4 ground connection after electric capacity C6 and electric capacity C7 successively, the backward end of described operational amplifier Q4 connects the backward end of described operational amplifier Q5 after resistance R9, the output terminal of described operational amplifier Q4 is also connected on the backward end of described calculation amplifier Q5 after resistance R8, resistance R7 is also connected between the backward end of described operational amplifier Q4 and output terminal, the OUT+ end of the pressure transducer described in termination in the same way of described operational amplifier Q5, the also ground connection after electric capacity C8 of end in the same way of described operational amplifier Q5, go back cross-over connection resistance R10 between the backward end of described operational amplifier Q5 and output terminal, be connected on the input end of described A/D converter after the output terminal of described operational amplifier Q5 is serially connected with resistance R12.
The utility model is also provided with voltage follower Q2, the end in the same way of described voltage follower Q2 gathers the input voltage of described constant-current source circuit, the backward end of described voltage follower Q2 is connected with its output terminal, the output terminal of described voltage follower Q2 is connected with described signal amplification circuit after bypass resistance R11, for described signal amplification circuit provides bias voltage.The output terminal of described voltage follower Q2 is also held with the VERF of described A/D converter and is connected, for described A/D converter provides reference voltage.
Beneficial effect: structure is simple, effectively reduces the precision that pressure sensor circuit Yin Wendu affects image data; Avoid because the fluctuation of pressure transducer feed circuit causes the problem that image data error is larger.
Accompanying drawing explanation
Fig. 1 is system chart of the present utility model;
Fig. 2 is circuit diagram of the present utility model.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the utility model is described in further detail.
The pressure acquisition circuit of a kind of constant current source driving pressure sensor as shown in Figure 1, its key is: comprise power supply 1, constant-current source circuit 2, pressure transducer 3, signal amplification circuit 4, A/D converter 5 and MCU6, the input end of pressure transducer 3 described in the output termination of described constant-current source circuit 2, in order to drive described pressure transducer 3, described pressure transducer 3 exports the voltage signal linear with pressure, signal amplification circuit 4 described in the output termination of described pressure transducer 3, described signal amplification circuit 4 passes to described A/D converter 5 after being amplified by this voltage signal, after described A/D converter 5 converts the voltage signal of simulation to discrete digital signal, this discrete digital signal passes to described MCU6 through SPI interface, described power supply 1 provides power supply for this pressure acquisition circuit.
Based on the pressure acquisition circuit of the constant current source driving pressure sensor of said structure, constant-current source circuit 2 is as the driving circuit of described pressure transducer 3, described pressure transducer 3 exports the weak voltage signals linear with pressure, this weak voltage signals, after signal amplification circuit 4 amplifies, converts discrete signal to for described MCU6 process by described A/D converter 5.
As can be seen from Figure 2, in the present embodiment, described power supply 1 adopts the power supply chip U1 of low noise, and the IN end of described power supply chip U1 connects the POWER end of described MCU6, cross-over connection electrochemical capacitor C1 between the IN end of described power supply chip U1 and ground after resistance R1; The EN end of MCU6 described in the EN termination of described power supply chip U1; The GND of described power supply chip U1 holds ground connection; Cross-over connection electrochemical capacitor C2 between the OUT end of described power supply chip U1 and ground, described electrochemical capacitor C2 is also parallel with electric capacity C3, the high pressure termination power VCC of described electric capacity C3, described electrochemical capacitor C1, C2 and electric capacity C3 are jointly for power supply 1 plays the effect of filtering and decoupling.
In the present embodiment, use the formal construction constant-current source circuit 2 of comparer Q1 and triode Q3, described triode Q3 adopts PNP type triode; Forward end ground connection after resistance R5 of described comparer Q1, and the IN-of pressure transducer 3 described in the forward termination of described comparer Q1 holds; The negative end of described comparer Q1 meets power supply VCC successively after resistance R3, resistance R2, the negative end also ground connection after resistance R4 of described comparer Q1, described resistance R4 two ends shunt capacitance C4; The output terminal of described comparer Q1 connects the base stage of described triode Q3 through resistance R6, the emitter of described triode Q3 meets described power supply VCC, the collector of described triode Q3 connects the IN+ end of described pressure transducer 3, and flying capcitor C5 between the collector of described triode Q3 and base stage.
Also can be found out by Fig. 2, for strengthening the weak voltage signals that described pressure transducer 3 exports, adopt the two-stage signal amplifying circuit 4 be made up of operational amplifier Q4 and operational amplifier Q5, the OUT-end of the pressure transducer 3 described in termination in the same way of described operational amplifier Q4, the OUT-end also ground connection after electric capacity C7 of described pressure transducer 3, and the end in the same way of described operational amplifier Q4 ground connection after electric capacity C6 and electric capacity C7 successively, the backward end of described operational amplifier Q4 connects the backward end of described operational amplifier Q5 after resistance R9, the output terminal of described operational amplifier Q4 is also connected on the backward end of described calculation amplifier Q5 after resistance R8, resistance R7 is also connected between the backward end of described operational amplifier Q4 and output terminal, the OUT+ end of the pressure transducer 3 described in termination in the same way of described operational amplifier Q5, the also ground connection after electric capacity C8 of end in the same way of described operational amplifier Q5, go back cross-over connection resistance R10 between the backward end of described operational amplifier Q5 and output terminal, be connected to after the output terminal of described operational amplifier Q5 is serially connected with resistance R12 on the input end of described A/D converter 5.
In the present embodiment, also be provided with voltage follower Q2, the end in the same way of described voltage follower Q2 gathers the input voltage of described constant-current source circuit 2, the backward end of described voltage follower Q2 is connected with its output terminal, the output terminal of described voltage follower Q2 is connected with described signal amplification circuit 4 after bypass resistance R11, for described signal amplification circuit 4 provides bias voltage.The output terminal of described voltage follower Q2 is also held with the VERF of described A/D converter 5 and is connected, for described A/D converter 5 provides reference voltage.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all do within spirit of the present utility model and principle any amendment, equivalent to replace and improvement etc., all should be included within protection domain of the present utility model.
Claims (5)
1. a pressure acquisition circuit for constant current source driving pressure sensor, is characterized in that: comprise power supply (1), constant-current source circuit (2), pressure transducer (3), signal amplification circuit (4), A/D converter (5) and MCU (6), the input end of pressure transducer (3) described in the output termination of described constant-current source circuit (2), in order to drive described pressure transducer (3), described pressure transducer (3) exports the voltage signal linear with pressure, signal amplification circuit (4) described in the output termination of described pressure transducer (3), described signal amplification circuit (4) passes to described A/D converter (5) after being amplified by this voltage signal, after described A/D converter (5) converts the voltage signal of simulation to discrete digital signal, this discrete digital signal passes to described MCU (6) through SPI interface, described power supply (1) provides power supply for this pressure acquisition circuit.
2. the pressure acquisition circuit of constant current source driving pressure sensor according to claim 1, it is characterized in that: described constant-current source circuit (2) comprises comparer Q1 and triode Q3, forward end ground connection after resistance R5 of described comparer Q1, and the IN-of pressure transducer (3) described in the forward termination of described comparer Q1 holds; The negative end of described comparer Q1 meets power supply VCC successively after resistance R3, resistance R2, the negative end also ground connection after resistance R4 of described comparer Q1, described resistance R4 two ends shunt capacitance C4; The output terminal of described comparer Q1 connects the base stage of described triode Q3 through resistance R6, the emitter of described triode Q3 meets described power supply VCC, the collector of described triode Q3 connects the IN+ end of described pressure transducer (3), and flying capcitor C5 between the collector of described triode Q3 and base stage.
3. the pressure acquisition circuit of constant current source driving pressure sensor according to claim 1, it is characterized in that: the two-stage amplifying circuit that described signal amplification circuit (4) is made up of operational amplifier Q4 and operational amplifier Q5, the OUT-end of the pressure transducer described in termination in the same way (3) of described operational amplifier Q4, the OUT-end also ground connection after electric capacity C7 of described pressure transducer (3), and the end in the same way of described operational amplifier Q4 ground connection after electric capacity C6 and electric capacity C7 successively, the backward end of described operational amplifier Q4 connects the backward end of described operational amplifier Q5 after resistance R9, the output terminal of described operational amplifier Q4 is also connected on the backward end of described calculation amplifier Q5 after resistance R8, resistance R7 is also connected between the backward end of described operational amplifier Q4 and output terminal, the OUT+ end of the pressure transducer described in termination in the same way (3) of described operational amplifier Q5, the also ground connection after electric capacity C8 of end in the same way of described operational amplifier Q5, go back cross-over connection resistance R10 between the backward end of described operational amplifier Q5 and output terminal, be connected on the signal input part of described A/D converter (5) after the output terminal of described operational amplifier Q5 is serially connected with resistance R12.
4. the pressure acquisition circuit of constant current source driving pressure sensor according to claim 1, it is characterized in that: be also provided with voltage follower Q2, the end in the same way of described voltage follower Q2 gathers the input voltage of described constant-current source circuit (2), the backward end of described voltage follower Q2 is connected with its output terminal, the output terminal of described voltage follower Q2 is connected with described signal amplification circuit (4) after bypass resistance R11, for described signal amplification circuit (4) provides bias voltage.
5. the pressure acquisition circuit of constant current source driving pressure sensor according to claim 4, it is characterized in that: the output terminal of described voltage follower Q2 is also held with the VERF of described A/D converter (5) and is connected, for described A/D converter (5) provides reference voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520777189.5U CN205038006U (en) | 2015-10-08 | 2015-10-08 | Pressure collecting circuit of constant current source driving pressure sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520777189.5U CN205038006U (en) | 2015-10-08 | 2015-10-08 | Pressure collecting circuit of constant current source driving pressure sensor |
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| Publication Number | Publication Date |
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| CN205038006U true CN205038006U (en) | 2016-02-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201520777189.5U Active CN205038006U (en) | 2015-10-08 | 2015-10-08 | Pressure collecting circuit of constant current source driving pressure sensor |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108716957A (en) * | 2018-06-21 | 2018-10-30 | 迈格仪表(成都)有限公司 | A kind of characterization buckling diaphragm capsule |
| CN110567616A (en) * | 2019-08-29 | 2019-12-13 | 北京自动化控制设备研究所 | Signal acquisition circuit for silicon piezoresistive pressure sensor unit |
-
2015
- 2015-10-08 CN CN201520777189.5U patent/CN205038006U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108716957A (en) * | 2018-06-21 | 2018-10-30 | 迈格仪表(成都)有限公司 | A kind of characterization buckling diaphragm capsule |
| CN110567616A (en) * | 2019-08-29 | 2019-12-13 | 北京自动化控制设备研究所 | Signal acquisition circuit for silicon piezoresistive pressure sensor unit |
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