A high stability preamplifier circuit

Abstract

The utility model proposes a high-stability preamplifier circuit, which includes a parallel amplifier circuit, an adding amplifier, a second-order high-pass filter, and a fourth-order low-pass filter. Compared with the previous low-frequency detection circuit, the first-stage amplifier circuit adds a parallel amplifier circuit, which can significantly reduce the influence of circuit voltage noise on radiation noise and improve the detection effect. The second-order high-pass filter and the fourth-order low-pass filter can filter out environmental noise and amplify the radiation noise to a level amplitude that can be easily read by an oscilloscope. Therefore, the preamplifier circuit can effectively process the noise in the low-frequency signal and improve the recognition accuracy of the radiation noise.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit design, in particular to a high-stability preamplifier circuit. Background Art

[0002] The low-frequency components of earthquakes contain more oil and gas related information. Based on this, high-precision ultra-low frequency signal detection has always been a focus in the field of geophysical exploration. As the high-frequency acoustic characteristics are continuously weakened, oil and gas detection is becoming increasingly difficult.

[0003] Ultra-low frequency signal detection has a certain application prospect in oil and gas detection. This technology can find oil and gas reservoirs by detecting changes in underground electromagnetic fields. The following is the working principle of ultra-low frequency signal detection in oil and gas detection: Ultra-low frequency signals usually refer to electromagnetic signals with frequencies ranging from tens of hertz to several thousand hertz. When these signals propagate in underground sediments, they will be affected by underground structures, rock types and underground fluids (such as oil, gas, and water) and change.

[0004] Detection equipment measures changes in these signals to infer the oil and gas conditions underground. Oil and gas detection: Ultra-low frequency signals can be used to find oil and gas reservoirs. The oil and gas content underground will affect the characteristics of the underground electromagnetic field, so potential oil and gas reservoirs can be located by detecting these characteristics. Geological surveys: Ultra-low frequency signals can also be used for geological surveys and mineral exploration. Different types of rock formations and mineral deposits underground may cause changes in the underground electromagnetic field, so these signals can be used to identify geological features.

[0005] The natural electromagnetic activity of the earth itself and human activities will generate many interference signals, which may affect the detection and interpretation of ultra-low frequency signals. Furthermore, the detection of ultra-low frequency signals requires a lot of data collection and processing, including complex signal processing algorithms and the establishment of geological models, which is crucial for accurately identifying oil and gas reservoirs. Utility Model Content

[0006] In view of this, the technical problem to be solved by the utility model is: how to provide a high-stability preamplifier circuit to improve the recognition accuracy of radiation noise in ultra-low frequency signals during geophysical exploration.

[0007] To achieve the above object, the utility model proposes a high-stability preamplifier circuit, which includes a parallel amplifier circuit, an adding amplifier, a second-order high-pass filter, and a fourth-order low-pass filter;

[0008] The parallel amplifier circuit is connected to the summing amplifier circuit, the mixed signal is first transmitted to the parallel amplifier circuit, the parallel amplifier circuit amplifies the mixed signal, and the amplified mixed signal is amplified again by the summing amplifier;

[0009] The second-order high-pass filter is connected to the summing amplifier, the fourth-order low-pass filter is connected to the second-order high-pass filter, and the second-order high-pass filter and the fourth-order low-pass filter are used to filter the environmental noise signal in the mixed signal;

[0010] The parallel amplifier circuit includes a first operational amplifier U1 and a second operational amplifier U1, the summing amplifier includes a third operational amplifier U3, the second-order high-pass filter includes a fourth operational amplifier U4A, and the fourth-order low-pass filter includes a fifth operational amplifier U5A and a sixth operational amplifier U5B.

[0011] Furthermore, the inverting input terminal of the first operational amplifier U1 is connected to the resistor R2 , and the resistor R1 is connected between the inverting input terminal of the first operational amplifier U1 and the output terminal of the first operational amplifier U1 .

[0012] Furthermore, the inverting input terminal of the second operational amplifier U2 is connected to the resistor R3, and the resistor R4 is connected between the inverting input terminal of the second operational amplifier U2 and the output terminal of the first operational amplifier U1.

[0013] Furthermore, the resistance value of the resistor R1 is equal to the resistance value of the resistor R4, and the resistance value of the resistor R2 is equal to the resistance value of the resistor R3.

[0014] Compared with the related art, the utility model proposes a high-stability preamplifier circuit, which has the following beneficial effects: compared with the previous low-frequency detection circuit, the first-stage amplifier circuit adds a parallel amplifier circuit, which can significantly reduce the influence of circuit voltage noise on radiation noise and improve the detection effect. The second-order high-pass filter and the fourth-order low-pass filter are set to filter out environmental noise and amplify the radiation noise to a level amplitude that can be easily read by an oscilloscope. Therefore, the preamplifier circuit can effectively process the noise in the low-frequency signal and improve the accuracy of identifying the radiation noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 4 is a circuit diagram of a high stability preamplifier circuit in an embodiment of the utility model. DETAILED DESCRIPTION

[0016] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0017] Please refer to the attached Figure 1 As shown, the utility model provides a high-stability preamplifier circuit, which includes a parallel amplifier circuit, an adding amplifier, a second-order high-pass filter, and a fourth-order low-pass filter.

[0018] The parallel amplifier circuit is connected to the summing amplifier circuit, and the mixed signal is first transmitted to the parallel amplifier circuit, and the mixed signal is amplified by the parallel amplifier circuit and the amplified mixed signal is amplified again by the summing amplifier. Among them, the mixed signal is a signal collected by the ultra-low frequency sensor including environmental noise, circuit noise and radiation noise.

[0019] The parallel amplifier circuit includes a first operational amplifier U1 and a second operational amplifier U2, as well as resistors R1, R2, R3, R4, capacitors C1, C2, C3, and C4.

[0020] The adding amplifier includes a third operational amplifier U3, and resistors R5, R6, R7, and decoupling capacitors C5 and C6.

[0021] Specifically, the inverting input terminal of the first operational amplifier U1 is connected to the resistor R2 , and the resistor R1 is connected between the inverting input terminal of the first operational amplifier U1 and the output terminal of the first operational amplifier U1 .

[0022] Specifically, the inverting input terminal of the second operational amplifier U2 is connected to the resistor R3, and the inverting input terminal of the second operational amplifier U2 and the output terminal of the first operational amplifier U1 are connected to the resistor R4. The resistor combination involved must be selected to minimize the thermal noise of the resistors, the resistance value of the resistor R1 is equal to the resistance value of the resistor R4, and the resistance value of the resistor R2 is equal to the resistance value of the resistor R3. At this point, the noise of the subsequent circuit after the parallel amplifier circuit and the summing amplifier can be ignored.

[0023] In order to filter out the environmental noise and amplify the radiated noise to a level that can be easily read by an oscilloscope, the circuit adopts a bandwidth of 0.1Hz to 10Hz. Specifically, the second-order high-pass filter is connected to the adding amplifier, and the fourth-order low-pass filter is connected to the second-order high-pass filter. The second-order high-pass filter and the fourth-order low-pass filter are used to filter the environmental noise signal in the mixed signal.

[0024] The bandwidth of the second-order high-pass filter is 0.1 Hz. The second-order high-pass filter includes a fourth operational amplifier U4A, and resistors R11, R12, R13, capacitors C11, C12, and decoupling capacitors C13 and C14.

[0025] The bandwidth of the fourth-order low-pass filter is 10 Hz. The fourth-order low-pass filter includes a fifth operational amplifier U5A and a sixth operational amplifier U5B, wherein the fifth operational amplifier U5A is connected to resistors R11, R12, R13, capacitors C11, C12, and decoupling capacitors C13 and C14. The sixth operational amplifier U5B is connected to resistors R14, R15, R16, capacitors C15 and C16.

[0026] Compared with the previous low-frequency detection circuit, the first-stage amplifier circuit adds a parallel amplifier circuit, which can significantly reduce the impact of circuit voltage noise on radiation noise and improve the detection effect. The second-order high-pass filter and fourth-order low-pass filter can filter out environmental noise and amplify the radiation noise to a level that can be easily read by an oscilloscope. Therefore, the preamplifier circuit can effectively process the noise in the low-frequency signal and improve the accuracy of identifying radiation noise.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A high stability preamplifier circuit, characterized in that: It includes a parallel amplifier circuit, a summing amplifier, a second-order high-pass filter, and a fourth-order low-pass filter; The parallel amplifier circuit is connected to the summing amplifier, the mixed signal is first transmitted to the parallel amplifier circuit, the mixed signal is amplified by the parallel amplifier circuit, and the amplified mixed signal is amplified again by the summing amplifier; The second-order high-pass filter is connected to the summing amplifier, the fourth-order low-pass filter is connected to the second-order high-pass filter, and the second-order high-pass filter and the fourth-order low-pass filter are used to filter the environmental noise signal in the mixed signal; The parallel amplifier circuit includes a first operational amplifier U1 and a second operational amplifier U1, the summing amplifier includes a third operational amplifier U3, the second-order high-pass filter includes a fourth operational amplifier U4A, and the fourth-order low-pass filter includes a fifth operational amplifier U5A and a sixth operational amplifier U5B.

2. The high stability preamplifier circuit according to claim 1, characterized in that: The inverting input terminal of the first operational amplifier U1 is connected to the resistor R2 , and the resistor R1 is connected between the inverting input terminal of the first operational amplifier U1 and the output terminal of the first operational amplifier U1 .

3. The high stability preamplifier circuit as claimed in claim 2, characterized in that: The inverting input terminal of the second operational amplifier U2 is connected to the resistor R3 , and the resistor R4 is connected between the inverting input terminal of the second operational amplifier U2 and the output terminal of the first operational amplifier U1 .

4. The high stability preamplifier circuit as claimed in claim 3, characterized in that: The resistance value of the resistor R1 is equal to the resistance value of the resistor R4 , and the resistance value of the resistor R2 is equal to the resistance value of the resistor R3 .

Images