CN210638828U - Pressure transmitter circuit - Google Patents
Pressure transmitter circuit Download PDFInfo
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- CN210638828U CN210638828U CN201921099342.8U CN201921099342U CN210638828U CN 210638828 U CN210638828 U CN 210638828U CN 201921099342 U CN201921099342 U CN 201921099342U CN 210638828 U CN210638828 U CN 210638828U
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- operational amplifier
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Abstract
The utility model discloses a pressure transmitter circuit belongs to pressure transmitter technical field, has solved the unstable problem of pressure transmitter signal output. A pressure transmitter circuit comprises a filtering amplifying circuit, a voltage-current conversion circuit and a lightning protection circuit; the filtering amplification circuit comprises an instrument operational amplifier U1, resistors R1-R3 and capacitors C1-C3; the input end of the instrument operational amplifier U1 receives an input voltage signal transmitted by a sensor, and the output end of the instrument operational amplifier U1 is connected with the voltage-current conversion circuit to output a voltage signal; the voltage-current conversion circuit is used for converting a voltage signal output by the instrument operational amplifier U1 into a current signal and outputting the current signal; the lightning protection circuit is used for receiving the current signal and protecting against lightning surge. The pressure transmitter can stably output signals.
Description
Technical Field
The utility model belongs to the technical field of pressure transmitter technique and specifically relates to a pressure transmitter circuit is related to.
Background
Many types and styles of pressure transmitters have been designed and developed, but the pressure transmitters currently on the market often have only partial functions, and particularly, the pressure transmitters with lightning protection, surge protection and three-prevention functions are almost rare. If the pressure transmitter needs to be installed outdoors in a severe industrial field environment, equipment damage caused by lightning strike often occurs; the environment is severe, and the high humidity and high dust can cause short circuit of the circuit or cause other influences; the motor around, converter also can produce more serious interference, and especially frequency conversion constant voltage water supply trade, pressure transmitter just can't normally work when starting the converter, and output signal is unstable, beats greatly, and high-power converter influences more greatly, if be close to the intercom in addition, also can make pressure transmitter signal output unstable.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to overcome an above-mentioned technique not enough at least, provide a pressure transmitter circuit.
In order to achieve the technical purpose, the technical scheme of the utility model provides a pressure transmitter circuit, which comprises a filtering amplifying circuit, a voltage-current converting circuit and a lightning protection circuit;
the filtering amplification circuit comprises an instrument operational amplifier U1, resistors R1-R3 and capacitors C1-C3;
the positive input end and the negative input end of the instrument operational amplifier U1 are respectively connected with two ends of a capacitor C3, two ends of a capacitor C3 are also respectively connected with one ends of a capacitor C1 and a capacitor C2, the other ends of the capacitor C1 and the capacitor C2 are grounded, and two ends of the capacitor C3 respectively receive input signals transmitted by a sensor through a resistor R2 and a resistor R1;
the pin 2 and the pin 3 of the instrument operational amplifier U1 are connected through a resistor R3, the pin 5 and the pin 6 are grounded, and the pin 8 is connected with a positive power supply; the input end of the instrument operational amplifier U1 receives an input voltage signal transmitted by a sensor, and the output end of the instrument operational amplifier U1 is connected with the voltage-current conversion circuit to output a voltage signal;
the voltage-current conversion circuit is used for converting a voltage signal output by the instrument operational amplifier U1 into a current signal and outputting the current signal;
the lightning protection circuit is used for receiving the current signal and protecting against lightning surge.
Furthermore, the filtering amplification circuit further comprises a capacitor C4 and a capacitor C5, after the capacitor C4 and the capacitor C5 are connected in parallel, one end of the capacitor C4 is connected with the pin 8 of the instrument operational amplifier U1, and the other end of the capacitor C5 is grounded.
Further, the voltage-current conversion circuit comprises an operational amplifier U2, a transistor U3, and resistors R10-R12; the positive input end of the operational amplifier U2 is connected with the output end of the instrument operational amplifier U1, the positive input end of the operational amplifier U2 is also connected with a power supply through a resistor R12, one end of the resistor R10 is connected with the positive input end of the operational amplifier U2, the output end of the instrument operational amplifier U1 and the resistor R12, the other end of the resistor R10 is grounded, and the negative input end of the operational amplifier U2 is grounded; the output end of the operational amplifier U2 is connected with the base of the transistor U3 through the resistor R11, the emitter of the transistor U3 is grounded, and the collector is used for providing a current signal for the lightning protection circuit.
Further, the pressure transmitter circuit also comprises a resistor R9 connected between the output end of the instrument operational amplifier U1 and the positive input end of the operational amplifier U2.
Further, the lightning protection circuit comprises a lightning surge protector G1, an overcurrent electronic protector RV1, a transient suppression diode TVS1, a diode Z1, inductors L1-L2 and a capacitor C1;
one ends of the lightning surge protector G1 and the over-current electronic protector RV1 are connected with the output end of the voltage-current conversion circuit and grounded, one end of the transient suppression diode TVS1 is connected with the over-current electronic protector RV1, the other end of the transient suppression diode TVS1 is connected with the lightning surge protector G1 and then grounded,
the diode Z1 is connected in parallel with the transient suppression diode TVS1, the anode of the diode Z1 is grounded, one ends of the inductor L1 and the inductor L2 are respectively connected with the cathode and the anode of the diode Z1, the other ends of the inductor L1 and the inductor L2 are respectively connected with two ends of the capacitor C1, and the end of the inductor L2 connected with the capacitor C1 is grounded.
Furthermore, the lightning protection circuit further comprises resistors R6-R7, capacitors C6-C7 and a diode D1 connected between the inductor L1 and the capacitor C1, the resistor R6 is connected with the output end of the voltage-current conversion circuit, is connected with the capacitor C6 in series and then is grounded, one end of a resistor R7 is connected with the positive electrode of the diode Z1, and the other end of the resistor R7 is grounded through the capacitor C7.
Compared with the prior art, the beneficial effects of the utility model include: the input signal of the sensor is filtered through the filtering amplifying circuit, and the signal amplification is carried out through the instrument operational amplifier, because the instrument operational amplifier has a very large common mode rejection ratio and has high input impedance, the output of the pressure transmitter circuit has a very strong stabilizing effect, the voltage signal output by the voltage circuit converting circuit is superposed on a direct current component, the interference of external interference to the signal is reduced, in addition, the lightning-resistant surge effect of the lightning protection circuit also enables the output of the pressure transmitter circuit to be more stable.
Drawings
Fig. 1 is a schematic structural diagram of a pressure transmitter circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a filter amplifier circuit and a voltage-current conversion circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of the lightning protection circuit according to the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Examples
The embodiment of the utility model provides a pressure transmitter circuit, the structure schematic diagram of pressure transmitter circuit, as shown in fig. 1, includes filtering and amplifying circuit, voltage current converting circuit and lightning protection circuit;
the filtering amplification circuit comprises an instrument operational amplifier U1, resistors R1-R3 and capacitors C1-C3;
the positive input end and the negative input end of the instrument operational amplifier U1 are respectively connected with two ends of a capacitor C3, two ends of a capacitor C3 are also respectively connected with one ends of a capacitor C1 and a capacitor C2, the other ends of the capacitor C1 and the capacitor C2 are grounded, and two ends of the capacitor C3 respectively receive input signals transmitted by a sensor through a resistor R2 and a resistor R1;
the pin 2 and the pin 3 of the instrument operational amplifier U1 are connected through a resistor R3, the pin 5 and the pin 6 are grounded, and the pin 8 is connected with a positive power supply; the input end of the instrument operational amplifier U1 receives an input voltage signal transmitted by a sensor, and the output end of the instrument operational amplifier U1 is connected with the voltage-current conversion circuit to output a voltage signal;
the voltage-current conversion circuit is used for converting a voltage signal output by the instrument operational amplifier U1 into a current signal and outputting the current signal;
the lightning protection circuit is used for receiving the current signal and protecting against lightning surge.
Preferably, the filter amplifying circuit further comprises a capacitor C4 and a capacitor C5, and after the capacitor C4 and the capacitor C5 are connected in parallel, one end of the capacitor C4 is connected to the pin 8 of the instrument operational amplifier U1, and the other end of the capacitor C5 is grounded.
FIG. 2 is a schematic structural diagram of a filter amplifier circuit and a voltage-current conversion circuit, wherein the voltage-current conversion circuit includes an operational amplifier U2, a transistor U3, and resistors R10-R12; the positive input end of the operational amplifier U2 is connected with the output end of the instrument operational amplifier U1, the positive input end of the operational amplifier U2 is also connected with a power supply through a resistor R12, one end of the resistor R10 is connected with the positive input end of the operational amplifier U2, the output end of the instrument operational amplifier U1 and the resistor R12, the other end of the resistor R10 is grounded, and the negative input end of the operational amplifier U2 is grounded; the output end of the operational amplifier U2 is connected with the base of the transistor U3 through the resistor R11, the emitter of the transistor U3 is grounded, and the collector is used for providing a current signal for the lightning protection circuit.
Preferably, the pressure transmitter circuit further comprises a resistor R9 connected between the output of the instrumentation operational amplifier U1 and the positive input of the operational amplifier U2.
It should be noted that the resistor R9 is a signal matching resistor, and the voltage-current conversion circuit superimposes the voltage signal output by the instrument operational amplifier U1 on the dc component.
Fig. 3 is a schematic structural diagram of a lightning protection circuit, which includes a lightning surge protector G1, an overcurrent electronic protector RV1, a transient suppression diode TVS1, a diode Z1, inductors L1 to L2, and a capacitor C1;
one ends of the lightning surge protector G1 and the over-current electronic protector RV1 are connected with the output end of the voltage-current conversion circuit and grounded, one end of the transient suppression diode TVS1 is connected with the over-current electronic protector RV1, the other end of the transient suppression diode TVS1 is connected with the lightning surge protector G1 and then grounded,
the diode Z1 is connected in parallel with the transient suppression diode TVS1, the anode of the diode Z1 is grounded, one ends of the inductor L1 and the inductor L2 are respectively connected with the cathode and the anode of the diode Z1, the other ends of the inductor L1 and the inductor L2 are respectively connected with two ends of the capacitor C1, and the end of the inductor L2 connected with the capacitor C1 is grounded.
The lightning surge protector G1 is specifically a ceramic gas discharge tube 2R230, the direct current breakdown voltage is about 230V, the impact breakdown voltage is less than about 800V, and the impact-resistant current capacity reaches 10KA, 8-20 us and 10 times;
the overcurrent electronic protector RV1 is a self-recovery fuse, the self-recovery fuse RV1 is an overcurrent electronic protection element, an output signal is only DC 4-20 mA during normal work, according to the characteristics of a U1 special integrated block, when the sensor is abnormally damaged, the maximum output signal is not more than 30mA, so that the maximum overload current can be 500mA, the self-recovery fuse does not influence the normal operation of the pressure transmitter during normal work, and the protection is cut off only when the high surge voltage impact current ratio is large;
the transient suppression diode TVS1 adopts a P6KE200A signal, the overvoltage protection is about 200V, and the pressure transmitter is supplied with direct current, so the diode Z1 is directly and reversely mounted, and the transient suppression diode TVS1 cannot break down in normal work
Preferably, the lightning protection circuit further includes resistors R6 to R7, capacitors C6 to C7, and a diode D1 connected between the inductor L1 and the capacitor C1, the resistor R6 is connected to the output terminal of the voltage-current conversion circuit, is connected in series with the capacitor C6, and is grounded, one end of the resistor R7 is connected to the positive electrode of the diode Z1, and the other end is grounded through the capacitor C7.
The utility model adopts the prepositive filter circuit to filter the input signal of the sensor and amplify the signal through the instrument operational amplifier, the instrument operational amplifier has very large common mode rejection ratio and high input impedance, and the amplification factor of the filter amplifier circuit is adjusted by R3; the instrumentation operational amplifier U1 is model AD8226BRMZ, the operational amplifier U2 is model ADA4091-2ACPZ, and the transistor U3 is model ZXT13N50DE 6.
In addition, dustproof, anticorrosion and waterproof materials are added between the pressure transmitter circuit and the pressure transmitter shell, so that the pressure transmitter has the functions of dust prevention, corrosion prevention and waterproof.
The utility model provides a pressure transmitter circuit, do the filtering through the input signal at filter amplifier circuit to the sensor, and put through instrument fortune and do signal amplification, because instrument fortune is put and is had very big common mode rejection ratio, and have high input impedance, so have very strong stabilizing effect to the pressure transmitter circuit, the voltage signal of voltage circuit converting circuit output stacks on the direct current component, reduce the interference of external disturbance to the signal, in addition, the lightning protection circuit's lightning stroke-resistant surge effect, also make the output of pressure transmitter circuit more stable.
It should be understood by those skilled in the art that, in the implementation, parameters of each element in the circuit, such as resistance values of resistors, etc., can be set and adjusted by those skilled in the art according to actual needs, and are not limited specifically herein.
The above description of the present invention does not limit the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the scope of the claims of the present invention.
Claims (6)
1. A pressure transmitter circuit is characterized by comprising a filtering amplification circuit, a voltage-current conversion circuit and a lightning protection circuit;
the filtering amplification circuit comprises an instrument operational amplifier U1, resistors R1-R3 and capacitors C1-C3;
the positive input end and the negative input end of the instrument operational amplifier U1 are respectively connected with two ends of a capacitor C3, two ends of a capacitor C3 are also respectively connected with one ends of a capacitor C1 and a capacitor C2, the other ends of the capacitor C1 and the capacitor C2 are grounded, and two ends of the capacitor C3 respectively receive input signals transmitted by a sensor through a resistor R2 and a resistor R1;
the pin 2 and the pin 3 of the instrument operational amplifier U1 are connected through a resistor R3, the pin 5 and the pin 6 are grounded, and the pin 8 is connected with a positive power supply; the input end of the instrument operational amplifier U1 receives an input voltage signal transmitted by a sensor, and the output end of the instrument operational amplifier U1 is connected with the voltage-current conversion circuit to output a voltage signal;
the voltage-current conversion circuit is used for converting a voltage signal output by the instrument operational amplifier U1 into a current signal and outputting the current signal;
the lightning protection circuit is used for receiving the current signal and protecting against lightning surge.
2. The pressure transmitter circuit of claim 1 wherein the filter amplifier circuit further comprises a capacitor C4 and a capacitor C5, wherein the capacitor C4 and the capacitor C5 are connected in parallel and have one end connected to pin 8 of the U1 and the other end connected to ground.
3. The pressure transmitter circuit of claim 1 wherein the voltage to current conversion circuit comprises an operational amplifier U2, a transistor U3, resistors R10-R12; the positive input end of the operational amplifier U2 is connected with the output end of the instrument operational amplifier U1, the positive input end of the operational amplifier U2 is also connected with a power supply through a resistor R12, one end of the resistor R10 is connected with the positive input end of the operational amplifier U2, the output end of the instrument operational amplifier U1 and the resistor R12, the other end of the resistor R10 is grounded, and the negative input end of the operational amplifier U2 is grounded; the output end of the operational amplifier U2 is connected with the base of the transistor U3 through the resistor R11, the emitter of the transistor U3 is grounded, and the collector is used for providing a current signal for the lightning protection circuit.
4. The pressure transmitter circuit of claim 3 further comprising a resistor R9 connected between the output of the instrumentation op-amp U1 and the positive input of the operational amplifier U2.
5. The pressure transmitter circuit of claim 1, wherein the lightning protection circuit comprises a lightning surge protector G1, an overcurrent electronic protector RV1, a transient suppression diode TVS1, a diode Z1, inductors L1-L2, and a capacitor C1;
one ends of the lightning surge protector G1 and the over-current electronic protector RV1 are connected with the output end of the voltage-current conversion circuit and grounded, one end of the transient suppression diode TVS1 is connected with the over-current electronic protector RV1, the other end of the transient suppression diode TVS1 is connected with the lightning surge protector G1 and then grounded,
the diode Z1 is connected in parallel with the transient suppression diode TVS1, the anode of the diode Z1 is grounded, one ends of the inductor L1 and the inductor L2 are respectively connected with the cathode and the anode of the diode Z1, the other ends of the inductor L1 and the inductor L2 are respectively connected with two ends of the capacitor C1, and the end of the inductor L2 connected with the capacitor C1 is grounded.
6. The pressure transmitter circuit of claim 5, wherein the lightning protection circuit further comprises resistors R6-R7, capacitors C6-C7 and a diode D1 connected between the inductor L1 and the capacitor C1, the resistor R6 is connected to the output end of the voltage-current conversion circuit and is connected in series with the capacitor C6 and then grounded, and one end of the resistor R7 is connected to the anode of the diode Z1 and the other end is grounded through the capacitor C7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921099342.8U CN210638828U (en) | 2019-07-12 | 2019-07-12 | Pressure transmitter circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921099342.8U CN210638828U (en) | 2019-07-12 | 2019-07-12 | Pressure transmitter circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210638828U true CN210638828U (en) | 2020-05-29 |
Family
ID=70799800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921099342.8U Expired - Fee Related CN210638828U (en) | 2019-07-12 | 2019-07-12 | Pressure transmitter circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210638828U (en) |
-
2019
- 2019-07-12 CN CN201921099342.8U patent/CN210638828U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200529 Termination date: 20210712 |