An excitation circuit and excitation method for a fluxgate magnetic probe.
By designing a segmented excitation circuit for the fluxgate magnetic probe, adaptive saturation excitation is achieved, solving the problem of high power consumption of the fluxgate magnetic probe, reducing the energy consumption of the magnetic probe, and ensuring its normal operating performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YICHANG TESTING TECHNIQUE RESEARCH INSTITUTE
- Filing Date
- 2022-11-08
- Publication Date
- 2026-05-26
Smart Images
Figure CN115856729B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fluxgate magnetic probe technology, specifically to an excitation circuit and excitation method for a fluxgate magnetic probe. Background Technology
[0002] In the fields of magnetic engineering technology, such as magnetic detection on unmanned platforms, target location and identification of magnetic fuses for sea mines, and geomagnetic exploration in the field, low-power fluxgate magnetometers (magnetic sensors) with long standby time are widely used. Among them, the magnetic probe is the core component of the fluxgate magnetometer, and its performance directly determines the performance of the magnetometer.
[0003] Existing fluxgate magnetometers use periodic excitation signals. Even after excitation saturation, the magnetometer continues to operate, resulting in ineffective operating time and invalid current within each cycle. This leads to high power consumption in fluxgate magnetometers; for example, a traditional full-cycle excitation fluxgate magnetometer consumes up to 0.5W. These high-power traditional full-cycle excitation fluxgate magnetometers cannot meet the long-term operating requirements of battery-powered devices.
[0004] To meet the low power consumption requirements of fluxgate magnetometers in engineering applications, it is necessary to invent a high-efficiency fluxgate magnetometer excitation method to reduce the power consumption of the fluxgate magnetometer, thereby reducing the overall power consumption of the fluxgate magnetometer and meeting the needs of engineering applications. Summary of the Invention
[0005] In view of this, the present invention provides an excitation circuit and excitation method for a fluxgate magnetometer, which can solve the technical problem of effectively reducing the power consumption of the magnetometer while ensuring the performance of the fluxgate magnetometer.
[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows.
[0007] An excitation circuit for a fluxgate magnetic probe includes:
[0008] Crystal oscillator, frequency divider, D flip-flop, first current amplifier, second current amplifier, first resistor, second resistor, first capacitor, second capacitor, transistor, excitation coil;
[0009] The crystal oscillator serves as the input to the excitation circuit, generating a high-frequency periodic signal. This high-frequency periodic signal is input to the frequency divider. The frequency divider divides the high-frequency periodic signal to obtain a square wave signal f1 of the desired frequency. The square wave signal f1 is input to the input of the first current amplifier and the data input of the D flip-flop. The data output of the D flip-flop is connected to the input of the second current amplifier. The first current amplifier is sequentially connected to the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor. The other end of the second resistor is connected to the output of the second current amplifier. The base of the transistor is connected to the output of the first current amplifier, and the collector of the transistor is connected to the clock control terminal of the D flip-flop.
[0010] Preferably, after the square wave signal f1 becomes high, the first current amplifier generates a monitoring signal S and controls the output state of the first current amplifier to become high according to the high-level state of the square wave signal f1, and inputs the monitoring signal S to the base of the transistor; the output state of the first current amplifier is high, and the output state of the second current amplifier is low; a positive excitation current is formed from the first current amplifier to the second current amplifier according to the level difference between the current amplifiers; the positive excitation current is injected sequentially into the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor; the positive excitation current starts the fluxgate magnetometer excitation process in the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor, and generates a dip on the monitoring signal S generated by the first current amplifier when the fluxgate magnetometer excitation is saturated. The transistor base controls the switching on and off based on the falling and rising edges of the dip signal generated on the monitoring signal S of the first current amplifier, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output terminal to generate a high level based on the pulse signal generated at the collector of the transistor and the high-level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a high level based on the high level generated at the output terminal of the D flip-flop. After the output state of the second current amplifier changes to a high level, it is the same as the output state of the first current amplifier, the levels at both ends of the excitation circuit are the same, and the positive excitation current is turned off. No current is consumed in the current cycle until the square wave signal f1 jumps to a low level at the end of the current cycle.
[0011] Preferably, when the square wave signal f1 transitions to a low level, the output state of the second current amplifier is high, while the output state of the first current amplifier is controlled to become low according to the low level state of the square wave signal f1; a reverse excitation current is formed from the second current amplifier to the first current amplifier based on the level difference between the current amplifiers, and the reverse excitation current is injected sequentially into the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor; the reverse excitation current starts the fluxgate magnetometer excitation process in the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor, and generates a dip signal on the monitoring signal S generated by the first current amplifier when the fluxgate magnetometer excitation is saturated; the base of the transistor is controlled according to the level difference between the second current amplifier and the first current amplifier. The falling and rising edges of the dip signal generated on the monitoring signal S control the switching on and off of the transistor, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output terminal to generate a low level based on the pulse signal generated at the collector of the transistor and the low level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a low level based on the low level generated at the output terminal of the D flip-flop. After the output state of the second current amplifier changes to a low level, it is the same as the output state of the first current amplifier, and the levels at both ends of the excitation circuit are the same, and the reverse excitation current is turned off. No current is consumed in the current cycle until the square wave signal f1 jumps to a high level at the end of the current cycle.
[0012] Preferably, the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor form a resonant circuit.
[0013] Preferably, the resistance values of the first resistor and the second resistor, and the capacitance values of the first capacitor and the second capacitor, are such that the first resistor, the second resistor, the first capacitor, and the second capacitor can resonate with the excitation coil at the excitation frequency.
[0014] The present invention provides an excitation method for a fluxgate magnetic probe, based on the excitation circuit of the fluxgate magnetic probe as described above, the excitation method comprising:
[0015] Step S1: Input a working power supply to the crystal oscillator of the excitation circuit of the fluxgate magnetic probe, and the crystal oscillator generates a periodic square wave signal;
[0016] Step S2: When the positive excitation current output by the first current amplifier saturates the fluxgate magnetic probe, a trough signal is formed on the monitoring signal S generated by the first current amplifier. The trough signal formed by the monitoring signal S controls the switching on and off of the base of the transistor; that is, when the fluxgate magnetic probe is saturated, the falling edge of the trough signal formed by the monitoring signal S controls the transistor to turn on, and the rising edge of the trough signal formed by the monitoring signal S controls the transistor to turn off; the switching on and off of the transistor will generate a pulse signal at the base of the transistor; the transistor sends the pulse signal generated at the base to the clock control terminal of the D flip-flop.
[0017] Step S3: After the clock control terminal of the D flip-flop receives the pulse signal generated by the base of the transistor, the D flip-flop latches the level of the square wave signal f1 received at the data input terminal of the D flip-flop to the output terminal of the D flip-flop.
[0018] Step S4: The level of the square wave signal f1 output by the D flip-flop controls the high-low level switching of the output state of the second current amplifier, so that the output state level of the second current amplifier remains consistent with the output state level of the first current amplifier after the magnetic flux gate probe is saturated, thereby achieving adaptive saturation excitation. The excitation current is immediately turned off after the magnetic flux gate probe is saturated, thereby greatly reducing the ineffective energy consumption in the excitation current working circuit after excitation saturation.
[0019] Beneficial effects:
[0020] (1) In order to reduce the power consumption of the magnetic probe, the present invention designs an efficient excitation method for the fluxgate magnetic probe, which adopts a segmented excitation circuit to effectively reduce the power consumption of the magnetometer while ensuring the performance of the fluxgate magnetometer.
[0021] (2) The present invention enables low-power operation of fluxgate magnetic probe.
[0022] (3) The excitation circuit of the present invention has a simple structure. Attached Figure Description
[0023] Figure 1 A schematic diagram of the excitation circuit structure provided by the present invention;
[0024] Figure 2 The schematic diagram of the excitation circuit provided by the present invention. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0026] like Figure 1As shown, the present invention proposes an excitation circuit for a fluxgate magnetic probe, the excitation circuit including a crystal oscillator, a frequency divider, a D flip-flop, a first current amplifier, a second current amplifier, a first resistor, a second resistor, a first capacitor, a second capacitor, a transistor, and an excitation coil.
[0027] The crystal oscillator serves as the input to the excitation circuit, generating a high-frequency periodic signal. This high-frequency periodic signal is input to the frequency divider. The frequency divider divides the high-frequency periodic signal to obtain a square wave signal f1 of the desired frequency. The square wave signal f1 is input to the input of the first current amplifier and the data input of the D flip-flop. The data output of the D flip-flop is connected to the input of the second current amplifier. The first current amplifier is sequentially connected to the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor. The other end of the second resistor is connected to the output of the second current amplifier. The base of the transistor is connected to the output of the first current amplifier, and the collector of the transistor is connected to the clock control terminal of the D flip-flop.
[0028] Further, after the square wave signal f1 becomes high, the first current amplifier generates a monitoring signal S and controls the output state of the first current amplifier to become high according to the high-level state of the square wave signal f1. The monitoring signal S is input to the base of the transistor. When the output state of the first current amplifier is high, the output state of the second current amplifier is low. Based on the level difference between the current amplifiers, a positive excitation current is formed flowing from the first current amplifier to the second current amplifier. The positive excitation current is injected sequentially into the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor. The positive excitation current starts the fluxgate magnetometer excitation process in the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor, and generates a dip signal on the monitoring signal S generated by the first current amplifier when the fluxgate magnetometer excitation is saturated. The base of the transistor controls the switching of the transistor according to the falling and rising edges of the dip signal generated on the monitoring signal S of the first current amplifier, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output to generate a high level based on the pulse signal generated at the collector of the transistor and the high-level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a high level based on the high level generated at the D flip-flop's output. After the second current amplifier's output state changes to a high level, it is the same as the first current amplifier's output state, resulting in the same voltage levels across the excitation circuit and the positive excitation current being turned off. No current is consumed during the current cycle until the square wave signal f1 jumps to a low level at the end of the current cycle.
[0029] Further, when the square wave signal f1 transitions to a low level, the output state of the second current amplifier is high, while the output state of the first current amplifier is controlled to become low according to the low level state of the square wave signal f1. The level difference between the current amplifiers will generate a reverse excitation current flowing from the second current amplifier to the first current amplifier. This reverse excitation current is sequentially injected into the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor. The reverse excitation current initiates the fluxgate magnetometer excitation process in the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor, and generates a dip signal on the monitoring signal S generated by the first current amplifier when the fluxgate magnetometer excitation is saturated. The base of the transistor controls the switching on and off of the transistor according to the falling and rising edges of the dip signal generated on the monitoring signal S of the first current amplifier, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output terminal to generate a low level according to the pulse signal generated at the collector of the transistor and the low level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a low level based on the low level generated at the output terminal of the D flip-flop. After the output state of the second current amplifier changes to a low level, it is the same as the output state of the first current amplifier, the voltage levels at both ends of the excitation circuit are the same, and the reverse excitation current is turned off; no current is consumed in the current cycle until the square wave signal f1 jumps to a high level at the end of the current cycle.
[0030] The first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor form a resonant circuit, which is the working circuit for the excitation current. When the excitation coil is saturated, a trough signal will be generated on the monitoring signal S generated by the first current amplifier. The generated trough signal automatically controls the high-low level switching of the output state of the second current amplifier when the excitation coil is saturated.
[0031] This invention addresses the issue of traditional fluxgate magnetometers operating throughout the entire periodic excitation cycle by proposing an adaptive saturation excitation method. The excitation circuit monitors the fluxgate magnetometer's excitation saturation and automatically shuts off the positive (or negative) excitation current when excitation saturation is detected. This reduces the excitation current's operating time in each working cycle, avoiding ineffective excitation after excitation saturation and significantly reducing the excitation current. Traditional fluxgate magnetometers operate throughout the entire cycle, consuming a large amount of ineffective excitation current in the first resistor, first capacitor, excitation coil, second capacitor, and second resistor. With the adaptive saturation excitation method, excitation current exists only in the first 2% to 5% of the periodic excitation time. When the excitation circuit detects excitation saturation, it automatically shuts off the excitation current, and the first resistor, first capacitor, excitation coil, second capacitor, and second resistor no longer consume current for the remaining 98% to 95% of the periodic excitation time. This invention's adaptive saturation excitation method ensures the saturation excitation required for normal operation of the fluxgate magnetometer while significantly reducing ineffective energy consumption in the excitation current operating circuit after excitation saturation.
[0032] In this embodiment, the fluxgate magnetic probe is a traditional parallel fluxgate magnetic probe, comprising one induction coil with W2 turns and two excitation coils with W1 turns. The two excitation coils are connected in series and placed inside the induction coil, and a magnetic permeability of [missing information] is placed inside the excitation coil. A soft magnetic material with a cross-sectional area of S.
[0033] Furthermore, after the square wave signal f1 becomes high, the first current amplifier outputs the positive excitation current required for the saturation excitation of the fluxgate magnetic probe. When the fluxgate magnetic probe is saturated, the output state of the second current amplifier is automatically changed to high, turning off the positive current of the fluxgate magnetic probe. No current is consumed in the current cycle until the square wave signal f1 jumps to low at the end of the current cycle. After the square wave signal f1 is low, the second current amplifier outputs the reverse excitation current required for the saturation excitation of the fluxgate magnetic probe. When the fluxgate magnetic probe is saturated, the output state of the second current amplifier is automatically changed to high, turning off the reverse current of the fluxgate magnetic probe. No current is consumed in the current cycle until the square wave signal f1 jumps to high at the end of the current cycle.
[0034] Furthermore, the resistance values of the first resistor and the second resistor, and the capacitance values of the first capacitor and the second capacitor, enable the first resistor, the second resistor, the first capacitor, and the second capacitor to resonate with the excitation coil at the excitation frequency.
[0035] Furthermore, both the first current amplifier and the second current amplifier are field-effect transistors (FETs). The first current amplifier, the first resistor, and the first capacitor form one FET amplifier circuit, which is connected to terminal A of the excitation coil. The second current amplifier, the second resistor, and the second capacitor form another FET amplifier circuit, which is connected to terminal B of the excitation coil.
[0036] like Figure 2 As shown, the gate G of the field-effect transistor is used for the square wave signal f1 input, the drain D is used for current output and sinking, the source S2 is used for excitation saturation monitoring and providing excitation energy, and generates a dimpling signal on the monitoring signal S when the excitation is saturated, and the source S1 is used for the excitation current to return to the power supply.
[0037] In this embodiment, the excitation state of the excitation coil is monitored through the source S2 of the field-effect transistor.
[0038] The fluxgate magnetic probe operates at a frequency of Under the magnetization effect of the excitation signal, the magnetic permeability of the magnetic core undergoes periodic saturation and unsaturation changes, thereby inducing a signal in the induction coil wound on the magnetic core that reflects the external magnetic field H0. This signal includes... ,2 And other harmonic components, among which even harmonics contain information about the external magnetic field. Specifically, the induced electromotive force caused by the external magnetic field... , is the permeability It is an even function, and its expression is as follows:
[0039]
[0040] in, For the excitation signal frequency, Where is the permeability of the magnetic core material, W2 is the number of turns of the induction coil, S is the cross-sectional area of the magnetic core material, and H0 is the value of the external magnetic field. denoted as the amplitude of each even harmonic component after the Fourier series expansion of the permeability of the magnetic core material, where n is an even number and t is the effective excitation time.
[0041] The crystal oscillator, made of ceramic or quartz, serves as a frequency source and has a frequency of 10kHz to 10MHz, used to generate periodic signals at a fixed frequency.
[0042] The frequency divider is a digital chip with a binary counter, used to generate a periodic square wave signal f1 of the required frequency.
[0043] like Figure 2As shown, the level signal of the source S2 of the current amplifier is used for excitation saturation monitoring. When the fluxgate magnetic probe is saturated, a sag signal will be generated and used as a monitoring signal S to monitor the working state of the fluxgate magnetic probe excitation coil and to control the excitation time of the fluxgate magnetic probe.
[0044] Furthermore, when the transistor is saturated based on the fluxgate magnetic probe excitation, the operating state of the excitation coil is monitored based on the trough signal corresponding to the monitoring signal S generated by the source S2 of the first current amplifier. The transistor is switched on and off by the falling edge and rising edge of the trough signal obtained on the monitoring signal S, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop.
[0045] Furthermore, the D flip-flop controls the high and low level switching of the output state of the second current amplifier based on the high and low level states of the pulse signal generated by the transistor and the square wave signal f1 output by the frequency divider, thereby timely cutting off the excitation current when the fluxgate magnetic probe is saturated.
[0046] In this invention, when the excitation coil is subjected to periodic current excitation from two current amplifiers, the permeability of the core material within the excitation coil tends to saturate. According to the BH curve of the core material, when the core material approaches saturation, the permeability of the core material... The rate of change of the permeability of the magnetic core material rapidly approaches 0. When the rate of change of the permeability of the core material rapidly approaches 0, according to the induced electromotive force formula, the inductance of the excitation coil rapidly approaches 0, and therefore, the inductive reactance rapidly approaches 0. When the inductive reactance of the excitation coil rapidly approaches 0, the current in the excitation circuit rapidly increases, and the periodic excitation signal forms a downward dip. Based on this dip, the present invention controls the switching on and off of the transistor collector, thereby generating a pulse signal at the transistor collector. The D flip-flop controls the high and low level switching of the output state of the second current amplifier based on the high and low level states of the pulse signal generated by the transistor and the square wave signal f1 output by the frequency divider. This immediately shuts off the excitation current when the fluxgate magnetic probe is saturated, ultimately achieving adaptive saturation excitation of the fluxgate magnetic probe and significantly reducing the ineffective energy consumption in the excitation current working circuit after excitation saturation.
[0047] The present invention also provides an excitation method for a fluxgate magnetic probe, the excitation method being based on the excitation circuit of the fluxgate magnetic probe as described above, the excitation method comprising the following steps:
[0048] Step S1: Input a working power supply to the crystal oscillator of the excitation circuit of the fluxgate magnetic probe, and the crystal oscillator generates a periodic square wave signal;
[0049] Step S2: When the positive excitation current output by the first current amplifier saturates the fluxgate magnetometer, a dip signal is formed on the monitoring signal S generated by the first current amplifier. The dip signal formed by the monitoring signal S controls the switching on and off of the transistor's base; that is, when the fluxgate magnetometer is saturated, the falling edge of the dip signal formed by the monitoring signal S controls the transistor to turn on, and the rising edge of the dip signal formed by the monitoring signal S controls the transistor to turn off. The switching on and off of the transistor will generate a pulse signal at the base of the transistor. The transistor sends the pulse signal generated at its base to the clock control terminal of the D flip-flop.
[0050] Step S3: After the clock control terminal of the D flip-flop receives the pulse signal generated by the base of the transistor, the D flip-flop latches the level of the square wave signal f1 received at the data input terminal of the D flip-flop to the output terminal of the D flip-flop.
[0051] Step S4: The level of the square wave signal f1 output by the D flip-flop controls the high-low level transition of the output state of the second current amplifier, ensuring that the output state level of the second current amplifier remains consistent with the output state level of the first current amplifier after the fluxgate magnetic probe excitation saturates. This achieves adaptive saturation excitation, and the excitation current is immediately turned off after the fluxgate magnetic probe excitation saturates. This significantly reduces the ineffective energy consumption in the excitation current operating circuit after excitation saturation.
[0052] The specific embodiments described above only illustrate the design principles of the present invention. The shapes and names of the components in this description may differ and are not limited. Therefore, those skilled in the art can modify or make equivalent substitutions to the technical solutions described in the foregoing embodiments; and these modifications and substitutions do not depart from the inventive spirit and technical solutions of the present invention, and should all fall within the protection scope of the present invention.
Claims
1. An excitation circuit for a fluxgate magnetic probe, characterized in that, The excitation circuit includes a crystal oscillator, a frequency divider, a D flip-flop, a first current amplifier, a second current amplifier, a first resistor, a second resistor, a first capacitor, a second capacitor, a transistor, and an excitation coil. The crystal oscillator serves as the input to the excitation circuit, generating a high-frequency periodic signal. This high-frequency periodic signal is input to the frequency divider. The frequency divider divides the high-frequency periodic signal to obtain a square wave signal f1 of the desired frequency. The square wave signal f1 is input to the input of the first current amplifier and the data input of the D flip-flop. The data output of the D flip-flop is connected to the input of the second current amplifier. The first current amplifier is sequentially connected to the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor. The other end of the second resistor is connected to the output of the second current amplifier. The base of the transistor is connected to the output of the first current amplifier, and the collector of the transistor is connected to the clock control terminal of the D flip-flop. After the square wave signal f1 goes high, the first current amplifier generates a monitoring signal S and controls the output state of the first current amplifier to go high according to the high-level state of the square wave signal f1. The monitoring signal S is input to the base of the transistor. When the output state of the first current amplifier is high, the output state of the second current amplifier is low. A positive excitation current is formed from the first current amplifier to the second current amplifier based on the level difference between the current amplifiers. The positive excitation current is injected sequentially into the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor. The positive excitation current starts the fluxgate magnetometer excitation process in the first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor, and when the fluxgate magnetometer excitation is saturated, a dip signal is generated on the monitoring signal S generated by the first current amplifier. The transistor base controls the switching on and off based on the falling and rising edges of the dip signal generated on the monitoring signal S of the first current amplifier, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output terminal to generate a high level based on the pulse signal generated at the collector of the transistor and the high-level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a high level based on the high level generated at the output terminal of the D flip-flop. After the output state of the second current amplifier changes to a high level, it is the same as the output state of the first current amplifier, the levels at both ends of the excitation circuit are the same, and the positive excitation current is turned off. No current is consumed in the current cycle until the square wave signal f1 jumps to a low level at the end of the current cycle. When the square wave signal f1 transitions to a low level, the output state of the second current amplifier is high, while the output state of the first current amplifier is controlled to become low according to the low level state of the square wave signal f1. Based on the level difference between the current amplifiers, a reverse excitation current is formed flowing from the second current amplifier to the first current amplifier. This reverse excitation current is sequentially injected into the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor. The reverse excitation current initiates the fluxgate magnetometer excitation process in the second resistor, the second capacitor, the excitation coil, the first capacitor, and the first resistor, and generates a dip signal on the monitoring signal S generated by the first current amplifier when the fluxgate magnetometer excitation is saturated. The base of the transistor is controlled according to the monitoring signal S generated by the first current amplifier. The falling and rising edges of the dip signal generated on signal S control the switching on and off of the transistor, thereby generating a pulse signal at the collector of the transistor. The pulse signal generated by the transistor is input to the clock control terminal of the D flip-flop. The D flip-flop controls its output terminal to generate a low level based on the pulse signal generated at the collector of the transistor and the low level state of the square wave signal f1 output by the frequency divider. The second current amplifier changes its output state to a low level based on the low level generated at the output terminal of the D flip-flop. After the output state of the second current amplifier changes to a low level, it is the same as the output state of the first current amplifier, and the levels at both ends of the excitation circuit are the same, and the reverse excitation current is turned off. No current is consumed in the current cycle until the square wave signal f1 jumps to a high level at the end of the current cycle.
2. The excitation circuit of claim 1, wherein The first resistor, the first capacitor, the excitation coil, the second capacitor, and the second resistor form a resonant circuit.
3. The excitation circuit of any one of claims 1-2, wherein, The resistance values of the first resistor and the second resistor, and the capacitance values of the first capacitor and the second capacitor, enable the first resistor, the second resistor, the first capacitor, and the second capacitor to resonate with the excitation coil at the excitation frequency.
4. An excitation method of a fluxgate magnetic probe, the excitation method being based on an excitation circuit of the fluxgate magnetic probe according to any one of claims 1 to 2, characterized in that, The incentive method includes the following steps: Step S1: Input a working power supply to the crystal oscillator of the excitation circuit of the fluxgate magnetic probe, and the crystal oscillator generates a periodic square wave signal; Step S2: When the positive excitation current output by the first current amplifier saturates the fluxgate magnetic probe, a trough signal is formed on the monitoring signal S generated by the first current amplifier. The trough signal formed by the monitoring signal S controls the switching on and off of the base of the transistor; that is, when the fluxgate magnetic probe is saturated, the falling edge of the trough signal formed by the monitoring signal S controls the transistor to turn on, and the rising edge of the trough signal formed by the monitoring signal S controls the transistor to turn off; the switching on and off of the transistor will generate a pulse signal at the base of the transistor; the transistor sends the pulse signal generated at the base to the clock control terminal of the D flip-flop. Step S3: After the clock control terminal of the D flip-flop receives the pulse signal generated by the base of the transistor, the D flip-flop latches the level of the square wave signal f1 received at the data input terminal of the D flip-flop to the output terminal of the D flip-flop. Step S4: The level of the square wave signal f1 output by the D flip-flop controls the high-low level switching of the output state of the second current amplifier, so that the output state level of the second current amplifier remains consistent with the output state level of the first current amplifier after the magnetic flux gate probe is saturated, thereby achieving adaptive saturation excitation. The excitation current is immediately turned off after the magnetic flux gate probe is saturated, thereby greatly reducing the ineffective energy consumption in the excitation current working circuit after excitation saturation.