CN218002731U - PT100 temperature signal transmitting circuit - Google Patents
PT100 temperature signal transmitting circuit Download PDFInfo
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- CN218002731U CN218002731U CN202222324352.5U CN202222324352U CN218002731U CN 218002731 U CN218002731 U CN 218002731U CN 202222324352 U CN202222324352 U CN 202222324352U CN 218002731 U CN218002731 U CN 218002731U
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Abstract
The application relates to a PT100 temperature signal transmitting circuit. The circuit comprises: the device comprises an H-bridge temperature acquisition module, an isolation amplifier and a protection module; the H-bridge temperature acquisition module comprises four bridge arms, wherein a PT100 temperature-sensitive resistor is installed on one of the four bridge arms, and resistors are installed on the other three bridge arms; the output end of the H-bridge temperature acquisition module is respectively connected with the protection module and the isolation amplifier, and the isolation amplifier outputs the amplified voltage signal. By adopting the method, the high-precision output of the temperature signal can be realized.
Description
Technical Field
The application relates to the technical field of power electronics, in particular to a PT100 temperature signal transmitting circuit.
Background
With the development of power electronic technology, a large amount of resistance change characteristics of the temperature-sensitive resistor are utilized to measure the temperature, and in this way, the temperature characteristics of the temperature-sensitive resistor need to be known firstly, and the detected resistance of the temperature-sensitive resistor is converted into corresponding voltage so as to monitor the temperature.
However, this method needs to detect the resistance change first and then query the temperature characteristic of the temperature sensitive resistor to know the corresponding temperature.
SUMMERY OF THE UTILITY MODEL
In view of the above, it is necessary to provide a PT100 temperature signal transmitting circuit in order to solve the above-mentioned problems.
A PT100 temperature signal transmitting circuit, the circuit comprising:
the device comprises an H-bridge temperature acquisition module, an isolation amplifier and a protection module;
the H-bridge temperature acquisition module comprises four bridge arms, wherein a PT100 temperature-sensitive resistor is arranged on one of the four bridge arms, and resistors are arranged on the other three bridge arms;
the output end of the H-bridge temperature acquisition module is respectively connected with the isolation amplifier and the protection module, and the isolation amplifier outputs the amplified voltage signal.
In one embodiment, the method further comprises the following steps: the resistors on the three bridge arms are respectively a first resistor, a second resistor and a third resistor; the positive electrode of the PT100 temperature-sensitive resistor is connected with a first resistor, the negative electrode of the PT100 temperature-sensitive resistor is grounded, and the other end of the first resistor is connected with VDD; one end of the second resistor is connected with VDD, the other end of the second resistor is connected with the third resistor, and the other end of the third resistor is grounded.
In one embodiment, the method further comprises the following steps: the output end of the H-bridge temperature acquisition module is the positive electrode of a PT100 temperature-sensitive resistor, and the voltage difference between one end of the second resistor connected with the third resistor is smaller than the voltage difference between the other end of the second resistor connected with the third resistor.
In one embodiment, the method further comprises the following steps: the positive electrode of the PT100 temperature-sensitive resistor is connected with the VINP end of the isolation amplifier; and one end of the second resistor, which is connected with the third resistor, is connected with the VINN end of the isolation amplifier.
In one embodiment, the method further comprises the following steps: the protection module comprises a resistance protection module and a diode protection module; two ends of the resistance protection module are respectively connected with a VDD and a ground end; the positive pole of the diode protection module is connected with the positive pole of the PT100 temperature-sensitive resistor, and the negative pole of the diode protection module is connected with an external power supply.
In one embodiment, the method further comprises the following steps: the resistance value of the first resistor is equal to that of the second resistor, and the resistance value of the third resistor is equal to that of the PT100 temperature-sensitive resistor at 0 ℃.
In one embodiment, the method further comprises the following steps: the resistance values of the first resistor and the second resistor are larger than the resistance values of the third resistor and the PT100 temperature-sensitive resistor.
The PT100 temperature signal transmitting circuit is different from directly reading resistance changes at two ends of a temperature-sensitive resistor, and linearly converts the resistance changes at the two ends of the temperature-sensitive resistor into voltage change output of an H bridge, so that the voltage change output is used as differential input of an isolation amplifier, and a linear relation between voltage drop on an output resistor and temperature change collected by a temperature collecting module is established. The resistance value of the PT100 temperature-sensitive resistor linearly changes along with the temperature within a certain range, so that the current temperature, namely the output voltage, namely the current temperature output can be known by solving the acquired output voltage through a simple linear relation. Then, isolation amplification is carried out through an isolation amplifier, the detection end is isolated from the output end, and high-precision and isolated temperature signal output can be realized.
Drawings
Fig. 1 is a circuit diagram of a PT100 temperature signal transmitting circuit in one embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further 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 present application and are not intended to limit the present application.
In one embodiment, there is provided a PT100 temperature signal transmitting circuit including:
the system comprises an H-bridge temperature acquisition module, an isolation amplifier and a protection module, wherein the H-bridge temperature acquisition module comprises four bridge arms, one of the four bridge arms is provided with a PT100 temperature-sensitive resistor, and the other three bridge arms are resistors; the output end of the H-bridge temperature acquisition module is respectively connected with the protection module and the isolation amplifier, and the isolation amplifier outputs the amplified voltage signal.
The PT100 temperature signal transmitting circuit is different from directly reading resistance changes at two ends of a temperature-sensitive resistor, and linearly converts the resistance changes at the two ends of the temperature-sensitive resistor into voltage change output of an H bridge, so that the voltage change output is used as differential input of an isolation amplifier, and a linear relation between voltage drop on an output resistor and temperature change collected by a temperature collecting module is established. The resistance value of the PT100 temperature-sensitive resistor linearly changes along with the temperature within a certain range, so that the current temperature, namely the output voltage, namely the current temperature output can be known by solving the acquired output voltage through a simple linear relation. Then, isolation amplification is carried out through an isolation amplifier, the detection end is isolated from the output end, and high-precision and isolated temperature signal output can be realized.
In one embodiment, as shown in fig. 1, the resistances of the three legs are a first resistance R1, a second resistance R2, and a third resistance R3; the positive electrode of the PT100 temperature-sensitive resistor RT is connected with a first resistor R1, the negative electrode of the PT100 temperature-sensitive resistor RT is grounded, and the other end of the first resistor R1 is connected with VCC1; one end of the second resistor R2 is connected with VCC1, the other end is connected with the third resistor R3, and the other end of the third resistor R3 is grounded GND1.
In one embodiment, the output end of the H-bridge temperature acquisition module is the positive electrode of the PT100 temperature-sensitive resistor, and the voltage difference between one end of the second resistor connected with the third resistor.
In one embodiment, the positive electrode of the PT100 temperature-sensitive resistor is connected with the VINP end of the isolation amplifier; one end of the second resistor, which is connected with the third resistor, is connected with the VINN end of the isolation amplifier.
In one embodiment, the protection module comprises a resistor-capacitor protection module and a Zener diode protection module; the resistance-capacitance protection module is connected between the output end of the H bridge and the input end of the isolation amplifier; the Zener diode protection module comprises two Zener diodes, wherein the anode of one Zener secondary is connected with the VINP end of the isolation amplifier, the cathode of the Zener secondary is connected with the ground end, the VINN end of the other Zener diode isolation amplifier and the cathode of the other Zener diode isolation amplifier are connected with the ground end. Through the protection module, high-voltage protection can be realized.
Specifically, the voltage stabilizing value of the Zener diode protection module is 5V, the voltage value of VDD is 5V, and the isolation amplifier is protected.
In one embodiment, the resistance of the first resistor is equal to the resistance of the second resistor, and the resistance of the third resistor is equal to the resistance of the PT100 temperature-sensitive resistor at 0 degrees. The PT100 has a resistance of 84.27-146.1 ohm within-40-120 ℃.
In one embodiment, the first resistor and the second resistor have a resistance of 4.99K Ω, the third resistor has a resistance of 100 Ω,
in one embodiment, the third resistor and the PT100 temperature sensitive resistor are grounded through the fourth resistor. The fourth resistor has a resistance of 499 Ω, and is used for increasing the working mode voltage.
In summary, the output range of the H bridge is-77.4-225.4 mV, the isolation amplifier amplifies 8.2 times, and the isolation terminal amplifies 5 times, for example, the final output voltage signal range is-3.166-9.223V. The output voltage and the temperature form a linear relation, the output voltage is 0V when the temperature is 0 ℃, the output voltage is-3.166V when the temperature is-40 ℃, and the output voltage is 9.223V when the temperature is 120 ℃.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (8)
1. A PT100 temperature signal transmitting circuit, the circuit comprising:
the device comprises an H-bridge temperature acquisition module, an isolation amplifier and a protection module;
the H-bridge temperature acquisition module comprises four bridge arms, wherein a PT100 temperature-sensitive resistor is installed on one of the four bridge arms, and resistors are installed on the other three bridge arms;
the output end of the H-bridge temperature acquisition module is respectively connected with the isolation amplifier and the protection module, and the isolation amplifier outputs the amplified voltage signal.
2. The PT100 temperature signal transmitting circuit of claim 1, wherein the resistors in the three legs are a first resistor, a second resistor and a third resistor;
the positive electrode of the PT100 temperature-sensitive resistor is connected with a first resistor, the negative electrode of the PT100 temperature-sensitive resistor is grounded, and the other end of the first resistor is connected with VDD;
one end of the second resistor is connected with VDD, the other end of the second resistor is connected with the third resistor, and the other end of the third resistor is grounded.
3. The PT100 temperature signal transmitting circuit of claim 1, wherein the output terminal of the H-bridge temperature acquisition module is a positive terminal of a PT100 temperature sensitive resistor, and a voltage difference between one terminal of the second resistor connected to the third resistor.
4. The PT100 temperature signal transmitting circuit of claim 3, wherein the positive electrode of the PT100 temperature sensitive resistor is connected with a VINP end of an isolation amplifier;
and one end of the second resistor, which is connected with the third resistor, is connected with the VINN end of the isolation amplifier.
5. The PT100 temperature signal transmitting circuit of claim 1, wherein the protection module includes a resistance protection module and a diode protection module;
two ends of the resistance protection module are respectively connected with a VDD and a ground end;
the positive pole of the diode protection module is connected with the positive pole of the PT100 temperature-sensitive resistor, and the negative pole of the diode protection module is connected with an external power supply.
6. The PT100 temperature signal transmitting circuit of claim 2, wherein the first resistor has a resistance equal to that of the second resistor, and the third resistor has a resistance equal to that of the PT100 temperature sensitive resistor at 0 degrees.
7. The PT100 temperature signal transmitting circuit of claim 6, wherein the first resistor and the second resistor have a resistance value greater than a resistance value of the third resistor and the PT100 temperature sensitive resistor.
8. The PT100 temperature signal transmitting circuit of claim 2, 3, 6 or 7, wherein the third resistor and the PT100 temperature sensitive resistor are grounded through a fourth resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222324352.5U CN218002731U (en) | 2022-08-31 | 2022-08-31 | PT100 temperature signal transmitting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222324352.5U CN218002731U (en) | 2022-08-31 | 2022-08-31 | PT100 temperature signal transmitting circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218002731U true CN218002731U (en) | 2022-12-09 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222324352.5U Active CN218002731U (en) | 2022-08-31 | 2022-08-31 | PT100 temperature signal transmitting circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218002731U (en) |
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2022
- 2022-08-31 CN CN202222324352.5U patent/CN218002731U/en active Active
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