CN220626530U - Electromagnetic field detection circuit and electromagnetic field detection device - Google Patents
Electromagnetic field detection circuit and electromagnetic field detection device Download PDFInfo
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- CN220626530U CN220626530U CN202322070386.0U CN202322070386U CN220626530U CN 220626530 U CN220626530 U CN 220626530U CN 202322070386 U CN202322070386 U CN 202322070386U CN 220626530 U CN220626530 U CN 220626530U
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- 239000003990 capacitor Substances 0.000 claims description 38
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Abstract
The utility model relates to the field of electronic circuits, in particular to an electromagnetic field detection circuit and an electromagnetic field detection device; the electromagnetic field detection circuit comprises an electromagnetic field signal detection module, a signal processing module electrically connected with the electromagnetic field signal detection module, an output interface circuit connected with the output of the signal processing module, and a power supply circuit for supplying power to the signal processing module; the electromagnetic field signal detection module comprises three sub-modules which are respectively used for detecting the intensity of electromagnetic field signals in the three-dimensional space in different dimensions, and finally, the signal processing module processes the electromagnetic field signal intensity in the three dimensions, and the electromagnetic field signal with the strongest dimension is obtained and then is output by the output interface circuit; the electromagnetic field detection circuit can monitor and data read weak effective electromagnetic field signals in different frequency bands, and can also realize measurement of interference signals in each frequency band.
Description
Technical Field
The utility model relates to the field of electronic circuits, in particular to an electromagnetic field detection circuit and an electromagnetic field detection device.
Background
In the automotive industry, keyless entry and start functions of a vehicle greatly improve convenience in use of the vehicle, and the functions have become basic configurations of the vehicle. The keyless entry and start function mainly comprises a key, a controller assembly BCM, a handle antenna, a start-stop button, an indoor antenna and other modules. In using the keyless entry and start-up function, as shown in fig. 1, the workflow is approximately as follows: the user presses the start-stop switch or presses the brake pedal, the indoor antenna of controller assembly BCM drive sends 125kHz low frequency electromagnetic field signal, the intelligent key receives 125kHz low frequency electromagnetic field signal and confirms the information in the low frequency electromagnetic field signal, the intelligent key sends 433MHz high frequency radio frequency signal after confirming the information in 125kHz low frequency signal successfully, the controller assembly BCM receives 433MHz high frequency radio frequency signal and decrypts and authenticates it, the controller assembly BCM judges whether the key is in the car according to the low frequency field intensity information in 433MHz high frequency signal, if the key decryption authentication is passed and the key is in the car, the vehicle is started.
When the keyless entry and start function of the workflow performs real vehicle testing and maintenance, as shown in fig. 2, a test method is generally adopted: reading and controlling data of the controller assembly BCM by using a PC (personal computer); meanwhile, the diagnostic instrument is used for converting data, generally, a USB data format and a CAN data format are converted, and a physical interface is provided for the diagnostic instrument and a vehicle bus by an OBD (on-board self-diagnostic) system; and then a 433MHz wireless receiver is used for reading and monitoring the 433MHz high-frequency radio frequency signal sent by the key.
In the scheme of the test equipment, the reading and monitoring of the 125kHz low-frequency electromagnetic field signal are absent, and the fault cannot be rapidly positioned when the system is abnormal. For example, when the 433MHz wireless receiver cannot collect the 433MHz high frequency radio frequency signal, the key may be in fault (software Bug or battery power failure) at this time, and the 433MHz high frequency electromagnetic field signal cannot be sent; it is also possible that the indoor antenna fails (opens), and a 125kHz low frequency electromagnetic field signal cannot be emitted, so that the key receives the corresponding information. The 125kHz low-frequency electromagnetic field signal cannot be read and monitored, so that the fault cannot be rapidly positioned. Therefore, a circuit device is needed that can read and monitor 125kHz electromagnetic field signals.
Disclosure of Invention
The utility model discloses an electromagnetic field detection circuit and an electromagnetic field detection device, which acquire electromagnetic field information through an electromagnetic field signal detection circuit, a signal processing module and an output interface circuit. The signal of the detected low-frequency electromagnetic field can be effectively converted into a signal which can be identified and displayed by the oscilloscope, so that the keyless entry of the automobile and the test and maintenance of the starting function system are facilitated.
The utility model discloses an electromagnetic field detection circuit, which comprises an electromagnetic field signal detection module, a signal processing module electrically connected with the electromagnetic field signal detection module, an output interface circuit connected with the output of the signal processing module, and a power supply circuit for providing a working power supply for the whole circuit. The electromagnetic field signal detection module comprises a first antenna module, a second antenna module and a third antenna module. The outputs of the first antenna module, the second antenna module and the third antenna module are respectively connected with the input port of the signal processing module in an electric signal mode.
It should be noted that the electromagnetic field signal detection module includes three parts, namely, a first antenna module, a second antenna module and a third antenna module, because in the three-dimensional space, in order to more accurately measure the strongest dimension of the electromagnetic field signal, electromagnetic field signals on the X-axis, the Y-axis and the Z-axis need to be measured respectively.
Further, the first antenna module comprises a first electromagnetic field antenna, a first resistor and a first capacitor, wherein the first magnetic field antenna is an inductor, and the first resistor and the first capacitor are connected in parallel at two ends of the first magnetic field antenna; the second antenna module comprises a second electromagnetic field antenna, a second resistor and a second capacitor, wherein the second electromagnetic field antenna is an inductor, and the second resistor and the second capacitor are connected in parallel at two ends of the second electromagnetic field antenna; the third antenna module comprises a third electromagnetic field antenna, a third resistor and a third capacitor, wherein the third electromagnetic field antenna is an inductor, and the third resistor and the third capacitor are connected in parallel at two ends of the third electromagnetic field antenna.
Preferably, the first resistor, the second resistor and the third resistor are all adjustable resistors; the first capacitor, the second capacitor and the third capacitor are all adjustable capacitors. The capacitor and the inductor are connected in parallel to form an LC resonant circuit, so that when the antenna is used, the value of the capacitor can be adjusted according to the frequency of the electromagnetic field to be detected, and the receiving frequency of the antenna module can be adjusted to a corresponding range. The resistor is used for adjusting the value of the resistor to improve the quality factor of the antenna module after adjusting the capacitor to change the frequency range received by the antenna module.
Further, the signal processing module comprises a signal amplifying circuit and a voltage comparing circuit; the output of the signal amplifying circuit is connected with the input of the voltage comparing circuit.
The signal amplifying circuit comprises a first amplifying circuit, a second amplifying circuit and a third amplifying circuit, and the first amplifying circuit, the second amplifying circuit and the third amplifying circuit are respectively used for amplifying the voltage signals which are acquired by the electromagnetic field signal detecting module and can reflect the sizes of electromagnetic field signals. Specifically, the first amplifying circuit is connected with the output of the first antenna module, the second amplifying circuit is connected with the output of the second antenna module, and the third amplifying circuit is connected with the output of the third antenna module.
Further, the first amplifying circuit comprises a first operational amplifier, a first feedback resistor and a first grounding resistor; the non-inverting input end and the inverting input end of the first operational amplifier are respectively connected with two ends of the first antenna module (namely the first electromagnetic field antenna); one end of the first grounding resistor is connected with the inverting input end of the first operational amplifier, and the other end of the first grounding resistor is grounded; the two ends of the first feedback resistor are respectively connected between the output end and the inverting input end of the first operational amplifier. Likewise, the second amplifying circuit includes a second operational amplifier, a second feedback resistor, and a second ground resistor; the non-inverting input end and the inverting input end of the second operational amplifier are respectively connected with two ends of the second antenna module (namely the second electromagnetic field antenna); one end of the second grounding resistor is connected with the inverting input end of the second operational amplifier, and the other end of the second grounding resistor is grounded; the two ends of the second feedback resistor are respectively connected between the output end and the inverting input end of the second operational amplifier. The third amplifying circuit comprises a third operational amplifier, a third feedback resistor and a third grounding resistor; the non-inverting input end and the inverting input end of the third operational amplifier are respectively connected with the two ends of the third antenna module (namely the third electromagnetic field antenna); one end of the third grounding resistor is connected with the inverting input end of the third operational amplifier, and the other end of the third grounding resistor is grounded; the two ends of the third feedback resistor are respectively connected between the output end and the inverting input end of the third operational amplifier.
Preferably, the first feedback resistor, the second feedback resistor, the third feedback resistor, the first ground resistor, the second ground resistor and the third ground resistor are all adjustable resistors. The purpose of this is to take the first amplifying circuit as an example, and the amplification factor between the output and the input is the value obtained by dividing the resistance value of the first feedback resistor by the resistance value of the first grounding resistor, so that the first feedback resistor and the first grounding resistor can be set as adjustable resistors for the purpose of freely adjusting the amplification factor of the output signal of the first amplifying circuit.
Further, the voltage comparison circuit includes a first comparator, a second comparator, and a third comparator. The non-inverting input ends of the first comparator, the second comparator and the third comparator are respectively connected with the output ends of the first amplifying circuit, the second amplifying circuit and the third amplifying circuit; the output ends of the first comparator, the second comparator and the third comparator are respectively connected with anodes of the first diode, the second diode and the third diode, and inverting input ends of the first comparator, the second comparator and the third comparator are respectively connected with cathodes of the first diode, the second diode and the third diode; cathodes of the first diode, the second diode and the third diode are connected together to serve as output and are connected with an output interface circuit. Three electromagnetic field signal detection modules are used for measuring electromagnetic field signals of a space electromagnetic field on an X axis, a Y axis and a Z axis respectively, but when the electromagnetic field signals are displayed, only one oscilloscope is needed to display the electromagnetic field signal with the strongest signal, so that a method of connecting the first comparator, the second comparator and the third comparator in parallel is adopted, and a voltage signal corresponding to the largest electromagnetic field signal is selected to output.
Further, the output interface circuit adopts BNC interface and is connected to the output ends of the first comparator, the second comparator and the third comparator.
Further, the power supply circuit comprises a control switch, a rechargeable battery, a charging chip and a charging interface; the rechargeable battery, the charging chip and the charging interface are sequentially connected; the output end of the rechargeable battery is connected with the signal processing module to supply power to the signal processing module; the control switch is connected between the rechargeable battery and the signal processing module and controls the on-off of a power supply in the whole circuit.
In the above-described circuit, the operation power source needs to be connected to each comparator and each operational amplifier, and the ground needs to be connected to the other circuit is not described.
In order to achieve the above purpose, the utility model also discloses an electromagnetic field detection device, which comprises the electromagnetic field detection circuit.
It should be noted that, the terms "first", "second", and the like are used herein merely to describe each component in the technical solution, and do not constitute a limitation on the technical solution, and are not to be construed as indicating or implying importance of the corresponding component; elements with "first", "second" and the like mean that in the corresponding technical solution, the element includes at least one.
The beneficial effects are that: the electromagnetic field detection circuit and the electromagnetic field detection device disclosed by the utility model are characterized in that the electromagnetic field signal capturing antenna, the signal amplifying circuit of the electromagnetic field signal, the voltage comparison circuit after the signal amplifying circuit and the output interface are sequentially connected, and are powered by the power supply circuit, so that the spatial electromagnetic field distribution in the three-dimensional space can be effectively captured; when in use, the strongest components of the spatial electromagnetic field signal in the X axis, the Y axis and the Z axis can be output by the output interface. The method is used for monitoring and reading data of weak effective electromagnetic field signals in different frequency bands and measuring interference signals in each frequency band.
Drawings
In order to more clearly illustrate the technical solution of the present utility model, the technical effects, technical features and objects of the present utility model will be further understood, and the present utility model will be described in detail below with reference to the accompanying drawings, which form a necessary part of the specification, and together with the embodiments of the present utility model serve to illustrate the technical solution of the present utility model, but not to limit the present utility model.
Like reference numerals in the drawings denote like parts, in particular:
FIG. 1 is a schematic diagram of a keyless entry and start-up system according to the background of the utility model;
FIG. 2 is a schematic diagram of a keyless entry and start-up system according to the background of the utility model;
FIG. 3 is a block diagram of a circuit configuration in the present utility model;
FIG. 4 is a schematic circuit diagram of the present utility model;
FIG. 5 is a schematic circuit diagram of the electromagnetic field signal detection module in the schematic circuit diagram shown in FIG. 4;
FIG. 6 is a schematic circuit diagram of the signal processing module in the schematic circuit diagram shown in FIG. 4;
FIG. 7 is a schematic circuit diagram of the signal amplifying circuit in the schematic circuit diagram shown in FIG. 4;
wherein: 100-electromagnetic field signal detection module, 200-signal processing module, 300-interface circuit, 400-power supply circuit, 110-first antenna module, 120-second antenna module, 130-third antenna module, 210-signal amplification circuit, 220-voltage comparison circuit, 201-first amplification circuit, 202-second amplification circuit, 203-third amplification circuit, L101-first electromagnetic field antenna, L102-second electromagnetic field antenna, L103-third electromagnetic field antenna, R111-first resistor, C112-first capacitor, R121-second resistor, C122-second capacitor, R131-third resistor, C132-third capacitor, R211-first feedback resistor, R212-first ground resistor, R221-second feedback resistor, R222-second ground resistor, R231-third feedback resistor, R232-third ground resistor, U1-first operational amplifier, U2-second operational amplifier, U3-third operational amplifier, U4-first U5-second BB comparator, U5-third BB battery, Q-third Q-switch, Q-charge diode, charging diode, and charging diode.
Detailed Description
The present utility model will be described in further detail with reference to the accompanying drawings and examples. Of course, the following specific examples are set forth only to illustrate the technical solution of the present utility model, and are not intended to limit the present utility model. Furthermore, the parts expressed in the examples or drawings are merely illustrative of the relevant parts of the present utility model, and not all of the present utility model.
An electromagnetic field detection circuit as shown in fig. 3 includes an electromagnetic field signal detection module 100, a signal processing module 200 electrically connected to both ends of the electromagnetic field signal detection module 100, an output interface circuit 300 connected to an output of the signal processing module 200, and a power supply circuit 400 for supplying power to the signal processing module 200.
As shown in fig. 4 and 5, in the present embodiment, the electromagnetic field signal detection module 100 includes a first antenna module 110, a second antenna module 120, and a third antenna module 130. The first antenna module 110 includes a first electromagnetic field antenna L101, a first resistor R111, and a first capacitor C112, where the first magnetic field antenna L101 is an inductor, and the first resistor R111 and the first capacitor C112 are connected in parallel to two ends of the first magnetic field antenna L101; the second antenna module 120 includes a second electromagnetic field antenna L102, a second resistor R121, and a second capacitor C122, where the second electromagnetic field antenna L102 is an inductor, and the second resistor R121 and the second capacitor C122 are connected in parallel to two ends of the second electromagnetic field antenna L102; the third antenna module 130 includes a third electromagnetic field antenna L103, a third resistor R131, and a third capacitor C132, where the third electromagnetic field antenna L103 is an inductor, and the third resistor R131 and the third capacitor C132 are connected in parallel to two ends of the third electromagnetic field antenna L103. The two ends of the first magnetic field antenna L101, the second magnetic field antenna L102, and the third magnetic field antenna L103 are also respectively used as output ends, and are connected to the signal processing module 200.
It should be noted that, the first resistor R111, the second resistor R121, and the third resistor R131 are all adjustable resistors; the first capacitor C112, the second capacitor C122 and the third capacitor C132 are all tunable capacitors. When the antenna module is used, the value of the capacitor can be adjusted according to the frequency of the electromagnetic field to be detected, and then the receiving frequency of the antenna module is adjusted to a corresponding range. The resistor is used for adjusting the value of the resistor to improve the quality factor of the antenna module after adjusting the capacitor to change the frequency range received by the antenna module.
It should be noted that when the electromagnetic field detection circuit is used in a specific detection device, the first magnetic field antenna L101, the second magnetic field antenna L102, and the third magnetic field antenna L103 need to be orthogonal to each other when in use, so as to achieve that the measured electromagnetic field signals are electromagnetic field signals in different dimensions (X-axis, Y-axis, and Z-axis) in a three-dimensional space.
As shown in fig. 6, in the present embodiment, the signal processing module 200 includes a signal amplifying circuit 210 and a voltage comparing circuit 220; the output of the signal amplification circuit 210 is connected to the input of the voltage comparison circuit 220.
As shown in fig. 7, in the present embodiment, the signal amplification circuit 210 includes a first amplification circuit 201, a second amplification circuit 202, and a third amplification circuit 203. The first amplifying circuit 210 is connected to the output end of the first antenna module 110, the second amplifying circuit 202 is connected to the output end of the second antenna module 120, and the third amplifying circuit 203 is connected to the output end of the third antenna module 130, and is respectively configured to amplify the voltage signal obtained by the electromagnetic field signal detecting module 100 and capable of reflecting the magnitude of the electromagnetic field signal. Specifically, the first amplifying circuit 201 is connected to both ends of the first electromagnetic field antenna L101, the second amplifying circuit 202 is connected to both ends of the second electromagnetic field antenna L102, and the third amplifying circuit 20 is connected to both ends of the third electromagnetic field antenna L103.
As shown in fig. 7, in the present embodiment, the first amplifying circuit 201 includes a first operational amplifier U1, a first feedback resistor R211, and a first ground resistor R212. Wherein, the non-inverting input terminal and the inverting input terminal of the first operational amplifier U1 are respectively connected to two ends of the first antenna module 110 (i.e. the first electromagnetic field antenna L101); one end of the first grounding resistor R212 is connected with the inverting input end of the first operational amplifier U1, and the other end of the first grounding resistor R is grounded; the two ends of the first feedback resistor R211 are respectively connected between the output end and the inverting input end of the first operational amplifier U1. Likewise, the second amplifying circuit 202 includes a second operational amplifier U2, a second feedback resistor R221, and a second ground resistor R222; the non-inverting input end and the inverting input end of the second operational amplifier U2 are respectively connected to two ends of the second antenna module 120 (i.e., the second electromagnetic field antenna L102); one end of the second grounding resistor R222 is connected with the inverting input end of the second operational amplifier U2, and the other end of the second grounding resistor R is grounded; both ends of the second feedback resistor R221 are respectively connected between the output terminal and the inverting input terminal of the second operational amplifier U2. The third amplifying circuit 203 includes a third operational amplifier U3, a third feedback resistor R231, and a third ground resistor R232; the non-inverting input end and the inverting input end of the third operational amplifier U3 are respectively connected with two ends of the third antenna module 130 (namely, the third electromagnetic field antenna L103); one end of the third grounding resistor R232 is connected with the inverting input end of the third operational amplifier U3, and the other end of the third grounding resistor R is grounded; both ends of the third feedback resistor R231 are respectively connected between the output end and the inverting input end of the third operational amplifier U3.
As shown in fig. 7, in the present embodiment, the first feedback resistor R211, the second feedback resistor R221, the third feedback resistor R231, the first ground resistor R212, the second ground resistor R222, and the third ground resistor R232 each employ an adjustable resistor. When in use, the amplification factors of the first amplification circuit 201, the second amplification circuit 202 and the third amplification circuit 203 in the whole circuit can be further adjusted by adjusting the resistance values of the first feedback resistor R211, the second feedback resistor R221, the third feedback resistor R231, the first grounding resistor R212, the second grounding resistor R222 and the third grounding resistor R232 according to the self requirements.
As shown in fig. 6, in the present embodiment, the voltage comparison circuit 220 includes a first comparator U4, a second comparator U5, and a third comparator U6. The non-inverting input ends of the first comparator U4, the second comparator U5 and the third comparator U6 are respectively connected with the output ends of the first amplifying circuit 201, the second amplifying circuit 202 and the third amplifying circuit 203; the output ends of the first comparator U4, the second comparator U5 and the third comparator U6 are respectively connected with anodes of the first diode Q1, the second diode Q2 and the third diode Q3, and inverting input ends of the first comparator U4, the second comparator U5 and the third comparator U6 are respectively connected with cathodes of the first diode Q1, the second diode Q2 and the third diode Q3; cathodes of the first diode Q1, the second diode Q2, and the third diode Q3 are connected together as an output, connected to the output interface circuit 300. Three electromagnetic field signal detection modules are used for measuring electromagnetic field signals of a space electromagnetic field on an X axis, a Y axis and a Z axis respectively, but when the electromagnetic field signals are displayed, only one oscilloscope is needed to display the electromagnetic field signal with the strongest signal, so that a parallel connection method of a first comparator U4, a second comparator U5 and a third comparator U6 is adopted, and a voltage signal corresponding to the largest electromagnetic field signal is selected to output.
As shown in fig. 4, in the present embodiment, the output interface 300 adopts a BNC interface, and is connected to the output ends of the first comparator U4, the second comparator U5 and the third comparator U6.
As shown in fig. 4, in the present embodiment, the power supply circuit 400 includes a control switch S, a rechargeable battery BB, a charging chip U7, and a charging interface Micro-B; the rechargeable battery BB, the charging chip U7 and the charging interface Micro-B are sequentially connected; the control switch S is connected between the rechargeable battery BB and the signal processing module 200, and controls the on/off of the power supply. In the signal processing module 200, the first operational amplifier U1, the second operational amplifier U2, the third operational amplifier U3, the first comparator U4, the second comparator U5 and the third comparator U6 are respectively powered by the rechargeable battery BB. Specifically, the positive and negative poles of rechargeable battery BB are respectively connected to VCC ports and ground ports of first operational amplifier U1, second operational amplifier U2, third operational amplifier U3, first comparator U4, second comparator U5, and third comparator U6.
When the electromagnetic field detection device comprising the electromagnetic field detection circuit is used, a control switch S is turned on, the equipment is placed in a detection environment, and the receiving range of electromagnetic field signals of each antenna module is adjusted to a required detection range by adjusting the values of a first capacitor C112, a second capacitor C122 and a third capacitor C132; each antenna module in the electromagnetic field signal detection module 100 amplifies the electromagnetic field signal after collecting the electromagnetic field signal by the signal amplifying circuit 210; the first feedback resistor R211, the second feedback resistor R221, the third feedback resistor R231, the first ground resistor R212, the second ground resistor R222 and the third ground resistor R232 can be adjusted to adjust the amplification factor of the signal amplifying circuit when necessary; the voltage comparison circuit 220 obtains the signal with the maximum voltage signal (i.e. corresponds to a certain dimension with the maximum signal intensity in the three-dimensional space), and finally outputs the signal through the output interface circuit BNC, the BNC interface can be connected with an oscilloscope, and the oscilloscope observes the collected electromagnetic field signal. The whole circuit can realize monitoring and data reading of weak effective electromagnetic field signals in different frequency bands and measurement of interference signals in each frequency band.
It should be noted that the foregoing examples are merely for clearly illustrating the technical solution of the present utility model, and those skilled in the art will understand that the embodiments of the present utility model are not limited to the foregoing, and that obvious changes, substitutions or alterations can be made based on the foregoing without departing from the scope covered by the technical solution of the present utility model; other embodiments will fall within the scope of the utility model without departing from the inventive concept.
Claims (12)
1. An electromagnetic field detection circuit, characterized in that: the device comprises an electromagnetic field signal detection module, a signal processing module, an output interface circuit and a power supply circuit;
the electromagnetic field signal detection module is electrically connected with the signal processing module, the signal processing module is electrically connected with the output interface circuit, and the power supply circuit provides a working power supply for the signal processing module;
the electromagnetic field signal detection module comprises a first antenna module, a second antenna module and a third antenna module, wherein the outputs of the first antenna module, the second antenna module and the third antenna module are respectively connected with the input port of the signal processing module through electric signals.
2. An electromagnetic field detection circuit as defined in claim 1, wherein:
the first antenna module comprises a first electromagnetic field antenna, a first resistor and a first capacitor, wherein the first electromagnetic field antenna is an inductor, and the first resistor and the first capacitor are connected in parallel at two ends of the first electromagnetic field antenna;
the second antenna module comprises a second electromagnetic field antenna, a second resistor and a second capacitor, wherein the second electromagnetic field antenna is an inductor, and the second resistor and the second capacitor are connected in parallel at two ends of the second electromagnetic field antenna;
the third antenna module comprises a third electromagnetic field antenna, a third resistor and a third capacitor, wherein the third electromagnetic field antenna is an inductor, and the third resistor and the third capacitor are connected in parallel to two ends of the third electromagnetic field antenna.
3. An electromagnetic field detection circuit as defined in claim 2, wherein:
the first resistor, the second resistor and the third resistor are all adjustable resistors;
the first capacitance, the second capacitance and the third capacitance are all adjustable capacitors.
4. An electromagnetic field detection circuit as defined in claim 2, wherein: the signal processing module comprises a signal amplifying circuit and a voltage comparing circuit; the output of the signal amplifying circuit is connected with the input of the voltage comparing circuit.
5. An electromagnetic field detection circuit as defined in claim 4, wherein: the signal amplifying circuit comprises a first amplifying circuit, a second amplifying circuit and a third amplifying circuit; the first amplifying circuit is connected with the output of the first antenna module, the second amplifying circuit is connected with the output of the second antenna module, and the third amplifying circuit is connected with the output of the third antenna module.
6. An electromagnetic field detection circuit as defined in claim 5, wherein:
the first amplifying circuit comprises a first operational amplifier, a first feedback resistor and a first grounding resistor; the non-inverting input end and the inverting input end of the first operational amplifier are respectively connected with two ends of the first electromagnetic field antenna; one end of the first grounding resistor is connected with the inverting input end of the first operational amplifier, and the other end of the first grounding resistor is grounded; the two ends of the first feedback resistor are respectively connected between the output end and the inverting input end of the first operational amplifier;
the second amplifying circuit comprises a second operational amplifier, a second feedback resistor and a second grounding resistor; the non-inverting input end and the inverting input end of the second operational amplifier are respectively connected with two ends of the second electromagnetic field antenna; one end of the second grounding resistor is connected with the inverting input end of the second operational amplifier, and the other end of the second grounding resistor is grounded; two ends of the second feedback resistor are respectively connected between the output end and the inverting input end of the second operational amplifier;
the third amplifying circuit comprises a third operational amplifier, a third feedback resistor and a third grounding resistor; the non-inverting input end and the inverting input end of the third operational amplifier are respectively connected with two ends of the third electromagnetic field antenna; one end of the third grounding resistor is connected with the inverting input end of the third operational amplifier, and the other end of the third grounding resistor is grounded; and two ends of the third feedback resistor are respectively connected between the output end and the inverting input end of the third operational amplifier.
7. An electromagnetic field detection circuit as defined in claim 6, wherein: the first feedback resistor, the second feedback resistor, the third feedback resistor, the first grounding resistor, the second grounding resistor and the third grounding resistor are all adjustable resistors.
8. An electromagnetic field detection circuit as defined in claim 5, wherein: the voltage comparison circuit comprises a first comparator, a second comparator and a third comparator; the non-inverting input ends of the first comparator, the second comparator and the third comparator are respectively connected with the output ends of the first amplifying circuit, the second amplifying circuit and the third amplifying circuit; the output ends of the first comparator, the second comparator and the third comparator are also respectively connected with anodes of a first diode, a second diode and a third diode, and inverting input ends of the first comparator, the second comparator and the third comparator are respectively connected with cathodes of the first diode, the second diode and the third diode; and cathodes of the first diode, the second diode and the third diode are connected together to serve as output and are connected with an output interface circuit.
9. An electromagnetic field detection circuit as defined in claim 1, wherein: the output interface circuit includes a BNC interface.
10. An electromagnetic field detection circuit as defined in claim 1, wherein: the power supply circuit comprises a control switch, a rechargeable battery, a charging chip and a charging interface; the rechargeable battery, the charging chip and the charging interface are sequentially connected; the output end of the rechargeable battery is connected with the signal processing module, and the control switch is connected between the rechargeable battery and the signal processing module.
11. An electromagnetic field detection circuit as defined in claim 10, wherein: the charging interface comprises a Micro-B interface.
12. An electromagnetic field detection apparatus comprising an electromagnetic field detection circuit as claimed in any one of claims 1 to 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322070386.0U CN220626530U (en) | 2023-08-03 | 2023-08-03 | Electromagnetic field detection circuit and electromagnetic field detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322070386.0U CN220626530U (en) | 2023-08-03 | 2023-08-03 | Electromagnetic field detection circuit and electromagnetic field detection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220626530U true CN220626530U (en) | 2024-03-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322070386.0U Active CN220626530U (en) | 2023-08-03 | 2023-08-03 | Electromagnetic field detection circuit and electromagnetic field detection device |
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| Country | Link |
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| CN (1) | CN220626530U (en) |
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2023
- 2023-08-03 CN CN202322070386.0U patent/CN220626530U/en active Active
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