CN214372678U - Pre-processing circuit for precession flowmeter and double-probe precession flowmeter - Google Patents
Pre-processing circuit for precession flowmeter and double-probe precession flowmeter Download PDFInfo
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- CN214372678U CN214372678U CN202023018717.9U CN202023018717U CN214372678U CN 214372678 U CN214372678 U CN 214372678U CN 202023018717 U CN202023018717 U CN 202023018717U CN 214372678 U CN214372678 U CN 214372678U
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Abstract
The utility model discloses a leading processing circuit and two probe precession flowmeters for precession flowmeter, include: the first amplifying circuit is used for amplifying the first electric signal and sending the first electric signal to the first filter circuit; the first filter circuit is used for carrying out low-pass filtering on the amplified first electric signal and sending the low-pass filtered first electric signal to the differential amplification circuit; the second amplifying circuit is used for amplifying the second electric signal and sending the second electric signal to the second filter circuit; the second filter circuit is used for carrying out low-pass filtering on the amplified second electric signal and sending the second electric signal to the differential amplifier circuit; the differential amplification circuit filters common-mode interference of the first electric signal and the second electric signal subjected to low-pass filtering to obtain a first output signal, and the first output signal is sent to the interference suppression and shaping circuit; and the interference suppression and shaping circuit carries out interference filtering and shaping on the first output signal to obtain a square wave which is used as a second output signal to be output. The amplification capability to the small flow signal is strong and the anti-noise capability is strong.
Description
Technical Field
The utility model relates to the technical field of circuits, especially, relate to a leading processing circuit and two probe precession flowmeters for precession flowmeter.
Background
At present, in the fields of natural gas trade metering settlement, industrial metering and process monitoring, a precession vortex gas flowmeter is taken as one of a plurality of gas metering instruments, the principle of the precession vortex gas flowmeter is that one or a plurality of signal probes are adopted to sense gas vibration after passing through a vortex generating body so as to calculate flow, at present, a piezoelectric crystal sensor is mostly adopted in the precession flowmeter, and a small signal of the sensor is amplified through a multistage amplifying circuit.
The signal sensed by the piezoelectric sensor is very weak and is influenced by a flow channel structure, the flow velocity, a vortex body, noise and the like, and the strength of the signal is exponentially related to the flow velocity, so that the conditions of signal loss and signal submergence are easily generated for small-flow signals, the metering performance of the flowmeter is influenced, and the pre-amplification processing of the signals is a technical problem.
Therefore, it is desirable to provide a pre-processing circuit for a precession flow meter and a dual probe precession flow meter that can amplify small flow signals and are robust against noise.
SUMMERY OF THE UTILITY MODEL
In order to solve the above problem, the utility model provides a leading processing circuit for precession flowmeter, include: the circuit comprises a first amplifying circuit, a second amplifying circuit, a first filter circuit, a second filter circuit, a differential amplifying circuit and an interference suppression and shaping circuit;
the first amplifying circuit is used for amplifying a first electric signal and sending the first electric signal to the first filter circuit;
the first filter circuit is used for carrying out low-pass filtering on the amplified first electric signal and sending the low-pass filtered first electric signal to the differential amplifier circuit;
the second amplifying circuit is used for amplifying a second electric signal and sending the second electric signal to the second filter circuit;
the second filter circuit is used for carrying out low-pass filtering on the amplified second electric signal and sending the second electric signal to the differential amplifier circuit;
the differential amplification circuit filters common-mode interference of the first electric signal and the second electric signal subjected to low-pass filtering to obtain a first output signal, and the first output signal is sent to the interference suppression and shaping circuit;
and the interference suppression and shaping circuit carries out interference filtering and shaping on the first output signal to obtain a square wave which is used as a second output signal to be output.
Preferably, the first amplification circuit includes: the circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor and a first amplifier;
the positive phase input end of the first amplifier is connected with one end of the first resistor, the negative phase input end of the first amplifier is connected with one end of the second resistor, one end of the fifth resistor and one end of the first capacitor, and the output end of the first amplifier is connected with the other end of the second resistor, the other end of the first capacitor and the first filter circuit;
the other end of the first resistor is connected with one end of the third resistor, one end of the fourth resistor and the first connecting point;
the other end of the third resistor is connected with a power supply, the other end of the fourth resistor is grounded, the other end of the fifth resistor is connected with one end of the second capacitor, and the other end of the second capacitor inputs a first electric signal.
Preferably, the second amplification circuit includes: the third capacitor, the fourth capacitor, the sixth resistor, the seventh resistor, the eighth resistor and the second amplifier;
a positive phase input end of the second amplifier is connected with one end of the sixth resistor, a negative phase input end of the second amplifier is connected with one end of the seventh resistor, one end of the eighth resistor and one end of the third capacitor, and an output end of the second amplifier is connected with the other end of the seventh resistor, the other end of the third capacitor and the second filter circuit;
the other end of the sixth resistor is connected with the first connecting point, the other end of the eighth resistor is connected with one end of the fourth capacitor, and the other end of the fourth capacitor inputs a second electric signal.
Preferably, the first filter circuit includes: a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor and a third amplifier;
a positive phase input end of the third amplifier is connected with one end of the ninth resistor and one end of the fifth capacitor, an inverted phase input end of the third amplifier is connected with one end of the tenth resistor and one end of the eleventh resistor, and an output end of the third amplifier is connected with the other end of the tenth resistor, one end of the sixth capacitor and the differential amplification circuit;
the other end of the eleventh resistor is grounded, the other end of the fifth capacitor is grounded, the other end of the sixth capacitor is connected with the other end of the ninth resistor and one end of a twelfth resistor, the other end of the twelfth resistor is connected with one end of a seventh capacitor, and the other end of the seventh capacitor is connected with the output end of the first amplifier.
Preferably, the second filter circuit includes: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, an eighth capacitor, a ninth capacitor, a tenth capacitor and a fourth amplifier;
an integral input end of the fourth amplifier is connected with one end of the tenth capacitor and one end of the thirteenth resistor, an inverting input end of the fourth amplifier is connected with one end of the fourteenth resistor and one end of the fifteenth resistor, and an output end of the fourth amplifier is connected with the other end of the fourteenth resistor, one end of the ninth capacitor and the differential amplification circuit;
the other end of the fifteenth resistor is grounded, the other end of the tenth capacitor is grounded, the other end of the thirteenth resistor is connected with the other end of the ninth capacitor and one end of a sixteenth resistor, the other end of the sixteenth resistor is connected with one end of an eighth capacitor, and the other end of the eighth capacitor is connected with the output end of the second amplifier.
Preferably, the differential amplification circuit includes: an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor and a fifth amplifying circuit;
a positive phase input end of the fifth amplifier is connected with one end of the seventeenth resistor and one end of the eighteenth resistor, an inverse phase input end of the fifth amplifier is connected with one end of the nineteenth resistor, one end of the twentieth resistor and one end of the eleventh capacitor, and an output end of the fifth amplifier is connected with the other end of the eleventh capacitor, the other end of the twentieth resistor, one end of the twenty-first resistor and the interference suppression and shaping circuit;
the other end and the adjustable end of the nineteenth resistor are both connected with one end of the twelfth capacitor, the other end of the twelfth capacitor is connected with the first filter circuit, and the other end of the twenty-first resistor is connected with a power supply;
the other end of the seventeenth resistor is connected with one end of the thirteenth capacitor, and the other end of the thirteenth capacitor is connected with the output end of the fourth amplifier;
the other end of the eighteenth resistor is connected with one end of the fourteenth capacitor, one end of the twenty-second resistor and one end of the twenty-third resistor;
the other end of the fourteenth capacitor, the other end of the twenty-second resistor and one end of the fifteenth capacitor are all grounded;
the other end of the twenty-third resistor is connected with the other end of the fifteenth capacitor and a power supply.
Preferably, the interference suppression and shaping circuit comprises: a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a sixteenth capacitor, a seventeenth capacitor and a comparator;
a positive phase input end of the comparator is connected with one end of the twenty-fourth resistor, one end of the twenty-fifth resistor and one end of the twenty-sixth resistor, an inverse phase input end of the comparator is connected with one end of the sixteenth capacitor and the output end of the fifth amplifier, and the output end of the comparator is connected with the other end of the twenty-sixth resistor;
the other end of the twenty-fifth resistor and one end of the seventeenth capacitor are both connected with a power supply;
the other end of the sixteenth capacitor, the other end of the seventeenth capacitor and the other end of the twenty-fourth resistor are all grounded.
In order to solve the problems, the utility model also provides a double-probe precession flowmeter, which comprises a pre-processing circuit for the precession flowmeter; and the signal output end of the first probe of the double-probe precession flowmeter is connected with the first amplifying circuit, and the signal output end of the second probe is connected with the second amplifying circuit.
Compared with the prior art, the pre-processing circuit for the precession flowmeter disclosed by the utility model amplifies two paths of weak input electric signals through the first amplifying circuit and the second amplifying circuit; filtering and inhibiting the common-mode interference signal of the high-frequency signal and the high-frequency signal of the probe through a first filter circuit, a second filter circuit and a differential amplification circuit, and performing secondary amplification processing on the effective voltage signal; and finally, by means of an interference suppression and shaping circuit, filtering of interference signals and shaping output of effective voltage signals acquired by the probe are achieved, the amplification effect is good, and the anti-noise capability is strong.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to denote like parts throughout the drawings. In the drawings:
fig. 1 is a schematic block diagram of a preprocessing circuit for a precession flow meter according to the present invention;
fig. 2 is a schematic connection diagram of a pre-processing circuit for a precession flow meter according to the present invention.
Description of the reference numerals
101 first amplifier circuit 102 second amplifier circuit
103 a first filter circuit 104 and a second filter circuit
105 differential amplification circuit 106 interference suppression and shaping circuit
VDD supply voltage GND ground
N1 first amplifier N2 second amplifier
N3 third Amplifier N4 fourth Amplifier
N5 fifth amplifier U1 comparator
R1 first resistor R2 second resistor
R3 third resistor R4 fourth resistor
R5 fifth resistor R6 sixth resistor
R7 seventh resistor R8 eighth resistor
R9 ninth resistor R10 tenth resistor
R11 eleventh resistor R12 twelfth resistor
R13 thirteenth resistor R14 fourteenth resistor
R15 fifteenth resistor R16 sixteenth resistor
R17 seventeenth resistor R18 eighteenth resistor
R19 nineteenth resistor R20 twentieth resistor
R21 twenty first resistor R22 twenty second resistor
R23 twenty-third resistor R24 twenty-fourth resistor
R25 twenty-fifth resistor R26 twenty-sixth resistor
C1 first capacitance C2 second capacitance
C3 third capacitance C4 fourth capacitance
C5 fifth capacitance C6 sixth capacitance
C7 seventh capacitance C8 eighth capacitance
C9 ninth capacitance C10 tenth capacitance
C11 eleventh capacitor C12 twelfth capacitor
C13 thirteenth capacitor C14 fourteenth capacitor
C15 fifteenth capacitor C16 sixteenth capacitor
First connection point of seventeenth capacitor VA of C17
Detailed Description
Exemplary embodiments of the present invention will be further described with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
In a first aspect, as shown in fig. 1, the present invention provides a pre-processing circuit for a precession flow meter, comprising: a first amplifying circuit 101, a second amplifying circuit 102, a first filter circuit 103, a second filter circuit 104, a differential amplifying circuit 105, and an interference suppressing and shaping circuit 106.
The first amplifying circuit 101 is configured to amplify the first electrical signal and send the first electrical signal to the first filtering circuit 103. The first filter circuit 103 is configured to perform low-pass filtering on the amplified first electrical signal, and send the low-pass filtered first electrical signal to the differential amplifier circuit 105. The second amplifying circuit 102 is used for amplifying the second electrical signal and sending the second electrical signal to the second filtering circuit 104. The second filter circuit 104 is configured to perform low-pass filtering on the amplified second electrical signal, and send the second electrical signal to the differential amplifier circuit 105. The differential amplification circuit 105 filters the common mode interference of the first electrical signal and the second electrical signal after the low-pass filtering to obtain a first output signal, and sends the first output signal to the interference suppression and shaping circuit 106. The interference suppression and shaping circuit 106 performs interference filtering and shaping on the first output signal to obtain a square wave, and the square wave is output as a second output signal.
The first amplification circuit 101 is used to amplify a weak electrical signal (charge) transmitted by the first probe. The first amplification circuit 101 includes: the circuit comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2 and a first amplifier N1.
A non-inverting input terminal of the first amplifier N1 is connected to one terminal of the first resistor R1, an inverting input terminal thereof is connected to one terminal of the second resistor R2, one terminal of the fifth resistor R5, and one terminal of the first capacitor C1, and an output terminal thereof is connected to the other terminal of the second resistor R2, the other terminal of the first capacitor C1, and the first filter circuit 103. The other end of the first resistor R1 is connected to one end of the third resistor R3, one end of the fourth resistor R4, and the first connection point VA. The other end of the third resistor R3 is connected to the power supply VDD, the other end of the fourth resistor R4 is grounded GND, the other end of the fifth resistor R5 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 inputs the first electrical signal. The second capacitor C2 is used for coupling the first electrical signal output by the first probe. The third resistor R3 and the fourth resistor R4 are connected in series to form a dc bias voltage.
The second amplifying circuit 102 is used for amplifying a weak electrical signal (charge) transmitted by the second probe. The second amplification circuit 102 includes: a third capacitor C3, a fourth capacitor C4, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a second amplifier N2.
A non-inverting input terminal of the second amplifier N2 is connected to one end of the sixth resistor R6, an inverting input terminal thereof is connected to one end of the seventh resistor R7, one end of the eighth resistor R8, and one end of the third capacitor C3, and an output terminal thereof is connected to the other end of the seventh resistor R7, the other end of the third capacitor C3, and the second filter circuit 104. The other end of the sixth resistor R6 is connected to the first connection VA, the other end of the eighth resistor R8 is connected to one end of the fourth capacitor C4, and the other end of the fourth capacitor C4 receives the second electrical signal. The fourth capacitor C4 is used for coupling the second electrical signal output by the second probe.
The first filter circuit 103 is configured to perform low-pass filtering, suppress a high-frequency interference signal, and secondarily amplify an output signal of the first amplifier N1. The first filter circuit 103 includes: a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and a third amplifier N3.
A non-inverting input terminal of the third amplifier N3 is connected to one end of the ninth resistor R9 and one end of the fifth capacitor C5, an inverting input terminal thereof is connected to one end of the tenth resistor R10 and one end of the eleventh resistor R11, and an output terminal thereof is connected to the other end of the tenth resistor R10, one end of the sixth capacitor C6, and the differential amplifier circuit 105. The other end of the eleventh resistor R11 is grounded GND, the other end of the fifth capacitor C5 is grounded GND, the other end of the sixth capacitor C6 is connected with the other end of the ninth resistor R9 and one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is connected with one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is connected with the output end of the first amplifier N1. The seventh capacitor C7 is used to couple the signal output by the first amplifier N1.
The second filter circuit 104 is used for low-pass filtering, suppressing high-frequency interference signals, and secondarily amplifying the output signal of the second amplifier N2. The second filter circuit 104 includes: a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and a fourth amplifier N4.
An integral input end of the fourth amplifier N4 is connected to one end of the tenth capacitor C10 and one end of the thirteenth resistor R13, an inverting input end is connected to one end of the fourteenth resistor R14 and one end of the fifteenth resistor R15, and an output end is connected to the other end of the fourteenth resistor R14, one end of the ninth capacitor C9, and the differential amplifier circuit 105. The other end of the fifteenth resistor R15 is grounded GND, the other end of the tenth capacitor C10 is grounded GND, the other end of the thirteenth resistor R13 is connected with the other end of the ninth capacitor C9 and one end of the sixteenth resistor R16, the other end of the sixteenth resistor R16 is connected with one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is connected with the output end of the second amplifier N2. The eighth capacitor C8 is used for coupling the signal output by the second amplifier N2.
The differential amplification circuit 105 is used for differentially amplifying the effective signal and suppressing the common-mode interference signal, and includes: an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23 and a fifth amplifying circuit.
A non-inverting input terminal of the fifth amplifier N5 is connected to one end of the seventeenth resistor R17 and one end of the eighteenth resistor R18, an inverting input terminal thereof is connected to one end of the nineteenth resistor R19, one end of the twentieth resistor R20 and one end of the eleventh capacitor C11, and an output terminal thereof is connected to the other end of the eleventh capacitor C11, the other end of the twentieth resistor R20, one end of the twenty-first resistor R21 and the interference suppression and shaping circuit 106. The other end and the adjustable end of the nineteenth resistor R19 are both connected with one end of a twelfth capacitor C12, the other end of the twelfth capacitor C12 is connected with the first filter circuit 103, and the other end of the twenty-first resistor R21 is connected with the power supply VDD. The other end of the seventeenth resistor R17 is connected to one end of a thirteenth capacitor C13, and the other end of the thirteenth capacitor C13 is connected to the output terminal of the fourth amplifier N4. The other end of the eighteenth resistor R18 is connected to one end of the fourteenth capacitor C14, one end of the twenty-second resistor R22, and one end of the twenty-third resistor R23. The other end of the fourteenth capacitor C14, the other end of the twenty-second resistor R22 and one end of the fifteenth capacitor C15 are all grounded to GND. The other end of the twenty-third resistor R23 is connected to the other end of the fifteenth capacitor C15 and the power supply VDD. The output signal of the first filter circuit 103 is coupled to the fifth amplifier N5 through a twelfth capacitor C12, and the output signal of the second filter circuit 104 is coupled to the fifth amplifier N5 through a thirteenth capacitor C13. The nineteenth resistor R19 is a variable resistor, and the nineteenth resistor R19 can adjust the amplification factor, so that the sensitivity adjustment under small-flow signals (weak signals) is realized.
The interference suppressing and shaping circuit 106 is used for filtering interference signals and shaping effective voltage signals sent by the probe into square wave signals, and comprises: a twenty-fourth resistor R24, a twenty-fifth resistor, a twenty-sixth resistor, a sixteenth capacitor C16, a seventeenth capacitor C17 and a comparator U1.
A positive phase input end of the comparator U1 is connected with one end of the twenty-fourth resistor R24, one end of the twenty-fifth resistor and one end of the twenty-sixth resistor, a negative phase input end is connected with one end of the sixteenth capacitor C16 and the output end of the fifth amplifier N5, and the output end is connected with the other end of the twenty-sixth resistor. The other end of the twenty-fifth resistor, the power supply end of the comparator U1 and one end of the seventeenth capacitor C17 are all connected with the power supply VDD. The other end of the sixteenth capacitor C16, the other end of the seventeenth capacitor C17 and the other end of the twenty-fourth resistor R24 are all connected to GND. The shaping circuit in the interference suppression and shaping circuit 106 adopts a hysteresis comparison circuit, and the adjustment of the threshold window can be realized through the twenty-fourth resistor R24, the twenty-fifth resistor and the twenty-sixth resistor, so that the adjustment is flexible and convenient, and the interference signal is further filtered.
The first amplifier N1, the second amplifier N2, the third amplifier N3, the fourth amplifier N4, and the fifth amplifier N5 are all low-power operational amplifiers. The comparator U1 is a micro-power small comparator U1. Power supply terminals of the first amplifier N1, the second amplifier N2, the third amplifier N3, the fourth amplifier N4, and the fifth amplifier N5 are all connected to a power supply VDD, and ground terminals of the first amplifier N1, the second amplifier N2, the third amplifier N3, the fourth amplifier N4, the fifth amplifier N5, and a ground terminal of the comparator U1 are all connected to GND.
In a second aspect, the present invention provides a dual-probe precession flowmeter, including the above pre-processing circuit for a precession flowmeter; the signal output end of the first probe of the double-probe precession flowmeter is connected with the first amplifying circuit 101, and the signal output end of the second probe is connected with the second amplifying circuit 102.
The embodiment has the advantages that the two paths of weak input electric signals can be amplified through the first amplifying circuit and the second amplifying circuit; filtering and inhibiting the common-mode interference signal of the high-frequency signal and the high-frequency signal of the probe through a first filter circuit, a second filter circuit and a differential amplification circuit, and performing secondary amplification processing on the effective voltage signal; and finally, by means of an interference suppression and shaping circuit, filtering of interference signals and shaping output of effective voltage signals acquired by the probe are achieved, the amplification effect is good, and the anti-noise capability is strong. In the signals processed by the first amplifying circuit, the second amplifying circuit, the first filter circuit, the second filter circuit and the differential amplifying circuit, the amplitude of the effective probe signal is amplified for multiple times, and high-frequency noise signals, probe vibration and other signals entering due to external interference are effectively inhibited; and finally, filtering the interference signal and shaping the effective voltage signal of the probe through an interference suppression and shaping circuit to form a square wave signal and then output the square wave signal. The embodiment of the application adopts the multistage amplifying circuit, and can play a remarkable amplifying effect on the weak signals of the probe under the small flow, so that the flow range of the flowmeter is improved, the flowmeter is universal under the flow of different calibers, and the applicability is high. By combining the filter circuit and the differential amplification circuit, noise interference signals from the outside and vibration signals of pipelines, probes and the like are effectively filtered, and the anti-seismic and anti-interference effects are greatly improved. The amplifier and the comparator both adopt micro-power consumption devices, and the power consumption of the pre-processing circuit is reduced.
The above description in this specification is merely illustrative of the present invention. Those skilled in the art can make various modifications or additions to the described embodiments or substitute them in a similar manner without departing from the scope of the present invention as defined in the following claims.
Claims (8)
1. A pre-processing circuit for a precession flow meter, comprising: the circuit comprises a first amplifying circuit, a second amplifying circuit, a first filter circuit, a second filter circuit, a differential amplifying circuit and an interference suppression and shaping circuit;
the first amplifying circuit is used for amplifying a first electric signal and sending the first electric signal to the first filter circuit;
the first filter circuit is used for carrying out low-pass filtering on the amplified first electric signal and sending the low-pass filtered first electric signal to the differential amplifier circuit;
the second amplifying circuit is used for amplifying a second electric signal and sending the second electric signal to the second filter circuit;
the second filter circuit is used for carrying out low-pass filtering on the amplified second electric signal and sending the second electric signal to the differential amplifier circuit;
the differential amplification circuit filters common-mode interference of the first electric signal and the second electric signal subjected to low-pass filtering to obtain a first output signal, and the first output signal is sent to the interference suppression and shaping circuit;
and the interference suppression and shaping circuit carries out interference filtering and shaping on the first output signal to obtain a square wave which is used as a second output signal to be output.
2. The pre-processing circuit for a precession flow meter according to claim 1, wherein the first amplification circuit comprises: the circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor and a first amplifier;
the positive phase input end of the first amplifier is connected with one end of the first resistor, the negative phase input end of the first amplifier is connected with one end of the second resistor, one end of the fifth resistor and one end of the first capacitor, and the output end of the first amplifier is connected with the other end of the second resistor, the other end of the first capacitor and the first filter circuit;
the other end of the first resistor is connected with one end of the third resistor, one end of the fourth resistor and the first connecting point;
the other end of the third resistor is connected with a power supply, the other end of the fourth resistor is grounded, the other end of the fifth resistor is connected with one end of the second capacitor, and the other end of the second capacitor inputs a first electric signal.
3. The pre-processing circuit for a precession flow meter according to claim 2, wherein the second amplification circuit comprises: the third capacitor, the fourth capacitor, the sixth resistor, the seventh resistor, the eighth resistor and the second amplifier;
a positive phase input end of the second amplifier is connected with one end of the sixth resistor, a negative phase input end of the second amplifier is connected with one end of the seventh resistor, one end of the eighth resistor and one end of the third capacitor, and an output end of the second amplifier is connected with the other end of the seventh resistor, the other end of the third capacitor and the second filter circuit;
the other end of the sixth resistor is connected with the first connecting point, the other end of the eighth resistor is connected with one end of the fourth capacitor, and the other end of the fourth capacitor inputs a second electric signal.
4. The pre-processing circuit for a precession flow meter according to claim 2, wherein the first filtering circuit comprises: a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor and a third amplifier;
a positive phase input end of the third amplifier is connected with one end of the ninth resistor and one end of the fifth capacitor, an inverted phase input end of the third amplifier is connected with one end of the tenth resistor and one end of the eleventh resistor, and an output end of the third amplifier is connected with the other end of the tenth resistor, one end of the sixth capacitor and the differential amplification circuit;
the other end of the eleventh resistor is grounded, the other end of the fifth capacitor is grounded, the other end of the sixth capacitor is connected with the other end of the ninth resistor and one end of a twelfth resistor, the other end of the twelfth resistor is connected with one end of a seventh capacitor, and the other end of the seventh capacitor is connected with the output end of the first amplifier.
5. The pre-processing circuit for a precession flow meter according to claim 3, wherein the second filter circuit comprises: a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, an eighth capacitor, a ninth capacitor, a tenth capacitor and a fourth amplifier;
an integral input end of the fourth amplifier is connected with one end of the tenth capacitor and one end of the thirteenth resistor, an inverting input end of the fourth amplifier is connected with one end of the fourteenth resistor and one end of the fifteenth resistor, and an output end of the fourth amplifier is connected with the other end of the fourteenth resistor, one end of the ninth capacitor and the differential amplification circuit;
the other end of the fifteenth resistor is grounded, the other end of the tenth capacitor is grounded, the other end of the thirteenth resistor is connected with the other end of the ninth capacitor and one end of a sixteenth resistor, the other end of the sixteenth resistor is connected with one end of an eighth capacitor, and the other end of the eighth capacitor is connected with the output end of the second amplifier.
6. The pre-processing circuit for a precession flow meter according to claim 5, wherein the differential amplification circuit comprises: an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor and a fifth amplifying circuit;
a positive phase input end of a fifth amplifier is connected with one end of the seventeenth resistor and one end of the eighteenth resistor, an inverted phase input end of the fifth amplifier is connected with one end of the nineteenth resistor, one end of the twentieth resistor and one end of the eleventh capacitor, and an output end of the fifth amplifier is connected with the other end of the eleventh capacitor, the other end of the twentieth resistor, one end of the twenty-first resistor and the interference suppression and shaping circuit;
the other end and the adjustable end of the nineteenth resistor are both connected with one end of the twelfth capacitor, the other end of the twelfth capacitor is connected with the first filter circuit, and the other end of the twenty-first resistor is connected with a power supply;
the other end of the seventeenth resistor is connected with one end of the thirteenth capacitor, and the other end of the thirteenth capacitor is connected with the output end of the fourth amplifier;
the other end of the eighteenth resistor is connected with one end of the fourteenth capacitor, one end of the twenty-second resistor and one end of the twenty-third resistor;
the other end of the fourteenth capacitor, the other end of the twenty-second resistor and one end of the fifteenth capacitor are all grounded;
the other end of the twenty-third resistor is connected with the other end of the fifteenth capacitor and a power supply.
7. The pre-processing circuit for a precession flow meter according to claim 6, wherein the interference rejection and shaping circuit comprises: a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a sixteenth capacitor, a seventeenth capacitor and a comparator;
a positive phase input end of the comparator is connected with one end of the twenty-fourth resistor, one end of the twenty-fifth resistor and one end of the twenty-sixth resistor, an inverse phase input end of the comparator is connected with one end of the sixteenth capacitor and the output end of the fifth amplifier, and the output end of the comparator is connected with the other end of the twenty-sixth resistor;
the other end of the twenty-fifth resistor and one end of the seventeenth capacitor are both connected with a power supply;
the other end of the sixteenth capacitor, the other end of the seventeenth capacitor and the other end of the twenty-fourth resistor are all grounded.
8. A dual probe precession flowmeter comprising a pre-processing circuit for a precession flowmeter according to any of claims 1 to 7; and the signal output end of the first probe of the double-probe precession flowmeter is connected with the first amplifying circuit, and the signal output end of the second probe is connected with the second amplifying circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023018717.9U CN214372678U (en) | 2020-12-15 | 2020-12-15 | Pre-processing circuit for precession flowmeter and double-probe precession flowmeter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202023018717.9U CN214372678U (en) | 2020-12-15 | 2020-12-15 | Pre-processing circuit for precession flowmeter and double-probe precession flowmeter |
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| Publication Number | Publication Date |
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| CN214372678U true CN214372678U (en) | 2021-10-08 |
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| CN202023018717.9U Active CN214372678U (en) | 2020-12-15 | 2020-12-15 | Pre-processing circuit for precession flowmeter and double-probe precession flowmeter |
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| CN (1) | CN214372678U (en) |
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