CN219265217U - Constant-current magnetic induction measuring circuit - Google Patents
Constant-current magnetic induction measuring circuit Download PDFInfo
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- CN219265217U CN219265217U CN202320319929.5U CN202320319929U CN219265217U CN 219265217 U CN219265217 U CN 219265217U CN 202320319929 U CN202320319929 U CN 202320319929U CN 219265217 U CN219265217 U CN 219265217U
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Abstract
The utility model discloses a constant-current magnetic induction measurement circuit which comprises a sending coil, a receiving coil and an iron rod, wherein the sending coil and the receiving coil are sleeved on the iron rod, the constant-current magnetic induction measurement circuit also comprises an alternating-current constant-current source, the alternating-current constant-current source is connected with the sending coil, and the equivalent input resistance of an equivalent circuit formed by the alternating-current constant-current source, the sending coil and the receiving coil is not affected by temperature to change the resistance. The device also comprises an amplifier, wherein the amplifier is connected with the receiving coil. The device also comprises a controller, wherein the controller is connected with the receiving coil or is connected with the receiving coil through an amplifier. The utility model adopts the mode of alternating current constant current source to excite, and the same branch current is equal according to the characteristic of the series circuit, so that the voltage at two ends of the equivalent inductance of the transmitting coil is stable as long as the stability of the current constant current source is ensured, the inductance value cannot be changed along with the change of temperature, the voltage of the transmitting coil is irrelevant to the temperature, and the influence of the temperature on the resistance of the coil can be eliminated, thereby eliminating the influence on the measurement precision.
Description
Technical Field
The utility model relates to the field of magnetic induction displacement sensors and magnetic induction thickness measuring circuits, in particular to a constant-current magnetic induction measuring circuit.
Background
Along with the development of technology, the current magnetic induction is used to perform operations such as thickness measurement and distance measurement, and the current magnetic induction measurement circuit mostly adopts an excitation mode of a constant voltage source, as shown in fig. 2, the output induction voltage of the current magnetic induction measurement circuit can be changed due to temperature change, and the resistance of the coil can be changed along with the temperature, so that the temperature drift of the resistance of the coil is generated, and the measurement accuracy is affected, so that it is very important to obtain the constant current magnetic induction measurement circuit for overcoming the defects.
Disclosure of Invention
In order to solve at least one technical problem, the utility model provides a constant-current magnetic induction measuring circuit which comprises a transmitting coil, a receiving coil and an iron rod, wherein the transmitting coil and the receiving coil are sleeved on the iron rod, the constant-current magnetic induction measuring circuit also comprises an alternating-current constant-current source, the alternating-current constant-current source is connected with the transmitting coil, and a circuit formed by the alternating-current constant-current source, the transmitting coil and the receiving coil is driven by a constant current so that the voltage loaded on an equivalent inductance of the coil is not influenced by the resistance of the coil, namely, the equivalent input resistance.
The device also comprises an amplifier, wherein the amplifier is connected with the receiving coil. The device also comprises a controller, wherein the controller is connected with the receiving coil or is connected with the receiving coil through an amplifier.
The principle is as follows: an alternating current signal is transmitted to the transmitting coil to generate an excitation magnetic field, the receiving coil senses the electric signal and amplifies the electric signal through the amplifier, the magnetic flux obtained by different positions of the formed electromagnetic induction sensor from the metal is also different, the sensed voltage is also different, and then the distance between the iron rod and the metal can be judged through the voltage received by the controller.
The traditional mode that adopts voltage excitation, the resistance of its sending coil can receive temperature variation, leads to the voltage at sending coil both ends to change, and then leads to the voltage change that receiving coil received, has influenced precision and stability.
The utility model adopts the mode of alternating current constant current source to excite, and the same branch current is equal according to the characteristic of the series circuit, so that the voltage at two ends of the equivalent inductance of the transmitting coil is stable as long as the stability of the current constant current source is ensured, the inductance value cannot be changed along with the change of temperature, the voltage of the transmitting coil is irrelevant to the temperature, and the influence of the temperature on the resistance of the coil can be eliminated, thereby eliminating the influence on the measurement precision.
Compared with the prior art, the utility model has the advantages that: the utility model has simple structure, solves the problem of temperature drift elimination due to the influence of temperature on the coil resistance by adopting a constant-current excitation mode, and ensures the accuracy of measurement.
Drawings
FIG. 1 is a schematic diagram of the structure of the present utility model;
FIG. 2 is a conventional equivalent circuit diagram;
FIG. 3 is an equivalent circuit diagram of the present utility model;
reference numerals: 1-a transmitting coil; 2-receiving coils; 3-iron rod; 4-an alternating current constant current source; rin-equivalent input resistance;
6-a controller; 7-metal; an 8-amplifier; 9-constant pressure source.
Detailed Description
The utility model will be described in detail below with respect to certain specific embodiments thereof in order to better understand the utility model and thereby to more clearly define the scope of the utility model as claimed. It should be noted that the following description is only some embodiments of the inventive concept and is only a part of examples of the present utility model, wherein the specific direct description of the related structures is only for the convenience of understanding the present utility model, and the specific features do not naturally and directly limit the implementation scope of the present utility model.
Referring to the drawings, the utility model adopts the following technical scheme that the constant-current magnetic induction measuring circuit comprises a transmitting coil 1, a receiving coil 2 and an iron rod 3, wherein the transmitting coil 1 and the receiving coil 2 are sleeved on the iron rod, and an alternating current constant current source 4, the alternating current constant current source 4 is connected with the transmitting coil 1, the voltage on the equivalent inductance of the transmitting coil 1 is constant, the temperature influence of the equivalent input resistance Rin of a circuit formed by the alternating current constant current source 4, the transmitting coil 1 and the receiving coil 2 is avoided, and the transmitting coil 1 and the receiving coil 2 are both copper coils.
In this embodiment, the device further includes an amplifier 8, a controller 6 and a metal 7, the amplifier 8 is connected with the receiving coil, the controller is connected with the receiving coil or connected with the receiving coil 2 through the amplifier, the iron rod 3 moves on one side of the metal 7, and the amplifier 8 adopts a well-known signal amplifier, so that a detailed description is not given here, and a judging program for judging the distance between the iron rod and the metal by the voltage is recorded in the controller 6.
The main structure of the controller is that the voltage signal amplified by the front stage is received, then the voltage signal is subjected to AC-DC conversion, then the ADC conversion is carried out, and finally the voltage signal enters the microcontroller for operation treatment. The metal is a ferromagnetic metal material.
The principle is as follows: an alternating current signal is transmitted to the transmitting coil 1 to generate an excitation magnetic field, the receiving coil 2 senses the electric signal and amplifies the electric signal through the amplifier 8, the magnetic fluxes obtained by different positions of the formed electromagnetic induction sensor from the metal are different, the sensed voltages are different, and then the distance between the iron rod and the metal can be judged through the voltage received by the controller 6.
The traditional mode that adopts voltage excitation, the resistance of its sending coil can receive temperature variation, leads to the voltage at sending coil both ends to change, and then leads to the voltage change that receiving coil received, has influenced precision and stability.
The utility model adopts the mode of alternating current constant current source 4 to excite, and the same branch current is equal according to the characteristics of the series circuit, so that the current at two ends of the sending coil is stable as long as the stability of the current constant current source is ensured, the inductance value is not changed along with the change of temperature, the voltage of the sending coil is irrelevant with the temperature, and the influence of the circuit on the electric 1 voltage of the sending coil caused by the equivalent input resistance Rin in the equivalent circuit can be eliminated.
Compared with the prior art, the utility model has the advantages that: the utility model has simple structure, solves the problem of temperature drift elimination due to the influence of temperature on the coil resistance by adopting a constant-current excitation mode, and ensures the accuracy of measurement.
The above description is not intended to limit the utility model to the particular embodiments disclosed, but to limit the utility model to the particular embodiments disclosed, as many variations, modifications, additions and substitutions are possible, without departing from the scope and spirit of the utility model as disclosed in the accompanying claims.
Claims (5)
1. The utility model provides a constant current magnetic induction measurement circuit, includes sending coil (1), receiving coil (2), iron rod (3), sending coil (1) and receiving coil (2) cover are on iron rod (3), its characterized in that: the alternating current constant current source (4) is further included, the alternating current constant current source (4) is connected with the transmitting coil (1), the voltage on the equivalent inductance of the transmitting coil (1) is constant, and the temperature influence of the equivalent input resistance (Rin) of a circuit formed by the alternating current constant current source (4), the transmitting coil (1) and the receiving coil (2) is avoided.
2. The constant-current magnetic induction measurement circuit of claim 1, wherein: the device also comprises an amplifier (8), wherein the amplifier (8) is connected with the receiving coil (2).
3. The constant-current magnetic induction measurement circuit of claim 1, wherein: the device also comprises a controller (6), wherein the controller (6) is connected with the receiving coil (2) or is connected with the receiving coil (2) through an amplifier (8).
4. The constant-current magnetic induction measurement circuit of claim 1, wherein: the iron rod (3) moves on one side of the metal (7).
5. The constant-current magnetic induction measurement circuit of claim 4, wherein: the metal (7) is a ferromagnetic metal material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320319929.5U CN219265217U (en) | 2023-02-10 | 2023-02-10 | Constant-current magnetic induction measuring circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320319929.5U CN219265217U (en) | 2023-02-10 | 2023-02-10 | Constant-current magnetic induction measuring circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219265217U true CN219265217U (en) | 2023-06-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320319929.5U Active CN219265217U (en) | 2023-02-10 | 2023-02-10 | Constant-current magnetic induction measuring circuit |
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| Country | Link |
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| CN (1) | CN219265217U (en) |
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2023
- 2023-02-10 CN CN202320319929.5U patent/CN219265217U/en active Active
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