JP2023535550A - Transmission system, method and apparatus for extremely low frequency magnetic sensing signals - Google Patents

Abstract

The present application discloses a transmission system, method and apparatus for extremely low frequency magnetic sensing signals, and relates to the field of excitation drive technology. The system includes a control module, a drive module and an antenna excitation module. The control module generates a periodic pulse signal, which is a periodic voltage signal, based on the input command, and the drive module controls the drive voltage for the input periodic pulse signal. to obtain a driving voltage signal, and the antenna excitation module performs excitation adjustment control according to the input driving voltage signal to obtain a magnetic sensing signal used for transmission. The technical configuration of the present application directly performs switching control through the I/O interface of a common controller, and solves the problem of too high voltage stress due to the high electromagnetic induction characteristics of the transmitting antenna itself. [Selection drawing] Fig. 3

Description

TECHNICAL FIELD The present invention relates to the technical field of excitation drive, and more particularly to a transmission system, method and apparatus for extremely low frequency magnetic sensing signals.

Extremely low frequencies are radio waves with frequencies of 3 Hz to 30 Hz and wavelengths of 100,000 kilometers to 1,000,000 kilometers. Ultra-low frequency radio waves can penetrate soil, seawater, and metal pipes, so they are applied to pipe inspection and communication inside and outside pipes.

In the communication process, an alternating magnetic field generated by exciting a transmitting antenna using an alternating electric field is induced by a receiving antenna to obtain an induced voltage, which is a process of transmitting and receiving signals. Only when the AC impedance of the transmitting antenna is large enough can it ensure that the voltage amplitude value applied across the transmitting antenna is large enough, thus completing the process of transmitting and receiving signals. Therefore, the AC impedance parameter directly affects the voltage amplitude value of the transmitted signal. The frequency of ultra-low frequency is much lower than that of high-frequency band electromagnetic waves such as 4G, and the AC impedance of a transmitting antenna is equal to the product of frequency and inductance. and the amount of inductance is large enough, the excitation process should consider the problem of the transmitting antenna induced electromotive force. In order to eliminate the voltage stress caused by the transmitting antenna induced electromotive force, the currently adopted method is to control the switch-on according to the preset fixed frequency, so that the triangular wave of extremely low frequency whose main frequency is fixed frequency A magnetic field signal is generated thereby dampening the voltage stress due to the transmitting antenna induced electromotive force.

However, the above method uses a triangular wave as the control signal, which is less suitable for I/O interfaces than the pulse signal, and in the above method, the electromagnetic induction operation of the transmitting antenna is in continuous mode, and the amperage of the coil is high. Therefore, it is natural that the size of the transmitting antenna increases, and the applied voltage stress increases with the increasing size of the transmitting antenna.

The present invention believes that the excitation drive of the transmitting antenna in the ultra-low frequency band cannot directly perform switching control through the ordinary controller I/O interface, and the voltage stress due to the high electromagnetic induction characteristics of the transmitting antenna is too high. To solve the problem, a system, method and apparatus for transmitting extremely low frequency magnetic sensing signals are provided.

An extremely low frequency magnetic sensing signal transmission system according to an embodiment of the present application includes a control module, a driving module, and an antenna excitation module,
The control module generates a periodic pulse signal, which is a periodic voltage signal, according to the input command,
The drive module performs drive voltage control on the input periodic pulse signal to obtain a drive voltage signal,
The antenna excitation module performs excitation adjustment control based on the input drive voltage signal to obtain a magnetic sensing signal used for transmission.

optionally, the drive module includes a block capacitor, a discharge resistor, a first flyback diode, a gate resistor, a gate source resistor and a gate voltage;
The input end of the control periodic pulse signal is connected in series with the block capacitor, the gate resistor, and the gate source resistor, and then grounded to form a charging circuit. Between the gate resistor and the gate source resistor is a gate voltage output an end is provided,
a discharge resistor and a first flyback diode are further provided between the input end of the control periodic pulse signal and the ground;
The block capacitor, the discharge resistor and the first flyback diode are connected in series to form a discharge circuit, wherein the discharge circuit discharges the block capacitor when the periodic pulse signal is at the low potential voltage value, and the gate voltage output terminal is output a low-potential driving voltage signal through, the low-potential voltage value is less than the highest voltage value of the periodic pulse signal,
The charging circuit charges the block capacitor when the periodic pulse signal is at a high potential voltage value, and outputs a high potential driving voltage signal through the gate voltage output terminal, and the high potential voltage value is equal to the periodic pulse signal is greater than or equal to the maximum voltage value of

Optionally, the charging circuit reduces the gate voltage output to zero when the control periodic pulse signal input continuously receives the periodic pulse signal of high potential voltage value.

Optionally, the periodic pulse signal has a voltage amplitude value of 0V to 5V, a signal frequency of 3Hz to 30Hz, and a duty ratio of 50%.

optionally, the antenna excitation module includes a power switching transistor, a DC resistor, a second flyback diode, a first antenna port, a second antenna port, a gate source voltage output and an antenna winding;
One side of the first antenna port is connected to the power supply, the other side is connected to the second antenna port after the antenna winding and the DC resistance are connected in series in that order, and the gate-source voltage output end is the power switching transistor. connected to the gate, the drain of the power switching transistor is connected to the second antenna port, the source of the power switching transistor is grounded;
One side of the second flyback diode is connected between the first antenna port and the antenna winding, the other side is connected between the DC resistor and the second antenna port, and the antenna winding, DC resistor and the second flyback diode is connected in series to form a magnetic reset circuit, which reduces the excitation current in the antenna winding when the power switching transistor is turned off;
The gate-source voltage output terminal is connected in series with the power switching transistor, the second antenna port, the DC resistor, the antenna winding, and the first antenna port to form an excitation circuit, and the excitation circuit is input to the gate-source voltage output terminal. Based on the voltage obtained, the output excitation current is controlled.

Optionally, the magnetic reset circuit turns off the power switching transistor and causes the current in the antenna winding to be zero by the magnetic reset circuit when the voltage value input to the drive voltage signal is less than the voltage value of the gate-source voltage. lower the
The excitation circuit turns on the power switching transistor when the voltage value input to the driving voltage signal is greater than or equal to the voltage value of the gate-source voltage, and the excitation circuit generates the magnetic sensing signal.

Optionally, the magnetic reset circuit discharges the current in the antenna winding when the power switching transistor is turned off, reduces the current in the antenna winding according to the first discharge period, and reduces the current in the antenna winding according to the first discharge period. is the ratio of the antenna inductance of the antenna winding to the DC resistance of the antenna winding, and the off period of the power switching transistor is longer than the first discharge period.

Optionally, the wire diameter of the enamelled wire used for the antenna winding, the number of turns of the winding and the radius of the winding are directly proportional.

Further, a method for transmitting an extremely low frequency magnetic sensing signal according to an embodiment of the present application includes:
generating a periodic pulse signal, which is a periodic voltage signal, based on the input command;
obtaining a drive voltage signal by performing drive voltage control on the input periodic pulse signal;
and performing excitation regulation control based on the input drive voltage signal to obtain a magnetic sensing signal used for transmission.

Furthermore, the extremely low frequency magnetic sensing signal transmitter according to the embodiment of the present application includes:
a pulse signal port for inputting a periodic pulse signal;
a signal ground port for providing ground;
a power port for inputting a power supply voltage;
a first antenna port and a second antenna port;
a controller electrically connected to any of the pulse signal port, the signal ground port, the power port, the first antenna port and the second antenna port and having an extremely low frequency magnetic sensing signal transmission system disposed thereon.

The present application provides an extremely low frequency magnetic sensing signal transmission system, method and apparatus, which includes a control module, a drive module and an antenna excitation module. The control module generates a periodic pulse signal, which is a periodic voltage signal, based on the input command, and the drive module performs drive voltage control on the input periodic pulse signal to generate the drive voltage signal. , and the antenna excitation module performs excitation adjustment control based on the input driving voltage signal to obtain the magnetic sensing signal used for transmission. According to the technical configuration of the present application, the problem of the transmission antenna induced electromotive force can be effectively solved, and the problem of voltage stress due to the transmission antenna induced electromotive force can also be solved.

The following briefly introduces the drawings that need to be used in the embodiments in order to explain the technical structure of the present application more clearly. Further drawings can be obtained based on the drawings.
1 is a schematic diagram of a transmission system for an extremely low frequency magnetic sensing signal according to an embodiment of the present application; FIG. 1 is a principle schematic diagram of a driving module circuit in an ultra-low frequency magnetic sensing signal transmission system according to an embodiment of the present application; FIG. 1 is a principle schematic diagram of an antenna excitation module circuit in an ultra-low frequency magnetic sensing signal transmission system according to an embodiment of the present application; FIG. 4 is a flowchart of a method for transmitting an extremely low frequency magnetic sensing signal according to an embodiment of the present application; 1 is a structural schematic diagram of a transmission device for ultra-low frequency magnetic sensing signals according to an embodiment of the present application; FIG.

The following clearly and completely describes the technical structure of the embodiments of the present invention in combination with the drawings in the embodiments of the present invention. but not all embodiments. All other embodiments obtained by persons skilled in the art without creative efforts based on the embodiments of the present invention shall fall within the protection scope of the present invention.

In the process of transmitting signals, the extremely low frequency transmission antenna has a frequency of 3 Hz to 30 Hz. is large enough to complete signal transmission, but increasing the inductance of the transmitting antenna will cause voltage stress due to the antenna induced electromotive force. , drive control and excitation adjustment control are performed on the extremely low frequency pulse signal, and the magnetic sensing signal used for transmission is obtained. When the inductance of the transmission antenna is increased, voltage stress is generated by the antenna induced electromotive force. It solves the problem, and realizes direct pulse control for the transmitting antenna with high electromagnetic induction through the common controller I/O interface.

In order to facilitate understanding of the technical configuration of the examples of the present application, before describing specific embodiments of the examples of the present application, some technical terms in the technical field to which the examples of the present application belong will be briefly explained. explain.

[excitation]
The antenna, as a highly inductive load with a core, performs an energy storage process when the power switch is turned on, and correspondingly releases energy by magnetic reset when it is turned off, so one cycle A magnetic equilibrium can always be maintained within, i.e. no flux accumulation can take place in the steady state.

[I/O interface]
Input/output refers to any operation, data transfer process that occurs between a program or device and a computer.

[Discontinuous Mode]
A mode of operation in which a zero value appears in the current change in the induction coil. That is, if the current in the induction coil increases or decreases periodically, the current in the inductor will become discontinuous if the current in the inductor decreases to zero before the next cycle begins.

[“Soft” switching]
Introduce resonance before and after the switching process to first reduce the voltage to zero before the switch is turned on and the current to zero before it is turned off to eliminate the superimposition of voltage and current in the switching process , thereby significantly reducing or even eliminating switching losses.

[Voltage stress]
Voltage stress is the ratio of the voltage applied in the field to the specification of the part. Generally, the design voltage stress does not exceed 90%.

[Induction voltage]
In the phenomenon of electromagnetic induction, an induced current is generated when a part of the conductor in a closed circuit moves to cut the magnetic lines of force in a magnetic field. If the circuit is not a closed circuit, an induced voltage will occur. An induced current has an induced voltage because the magnetic field produces electricity.

[AC impedance]
Assuming that the frequency of each electricity in the circuit is f and the angular frequency is w, the AC impedance of the resistor is its resistance value R, and the impedance of the inductor whose inductance value is L is jwL (j is an imaginary unit ), and the impedance of a capacitor with a capacitance value of C is 1/(jwC).

[Amplitude]
It is the maximum absolute value of the instantaneous appearance of the alternating current within one period, also one sine wave, and half the distance from the peak to the trough.

[MOS (Metal Oxide Semiconductor) transistor switching circuit]
A MOS transistor switching circuit is a circuit constructed on the principle that a gate g of a MOS transistor controls on/off of a source s and a drain d of the MOS transistor. MOS transistors are divided into N-channel and P-channel. The characteristic of NMOS in the present invention is that it becomes conductive when the gate-source voltage Vgs is greater than a certain value, and applies when the source s is grounded, and the gate voltage Vg is a parameter It should be higher than the predetermined gate-source voltage Vgs in the manual, the drain d is connected to the power supply, and the source s is grounded. It should be noted that the gate-source voltage Vgs is the voltage difference between the gate g and the source s, so when the NMOS is driven on the high side, when the drain d and the source s are conducting, the potential of the drain d and the source s is Equally, the gate g must be higher than the voltage of the source s and the drain d so that the drain d and the source s can continue to conduct.

FIG. 1 is a schematic diagram of a transmission system for ultra-low frequency magnetic sensing signals according to an embodiment of the present application.
As shown in FIG. 1, the ultra-low frequency magnetic sensing signal transmission system according to the embodiment of the present application uses a 5-pin interface, is connected between the electromagnetic receiving device and the controller I/O interface, and the controller I/O interface inputs a control signal, transmits the control signal to the transmission system of the present application, performs drive control and excitation adjustment control on the control signal by the transmission system of the present application, outputs a magnetic sensing signal, and sends it to the electromagnetic receiving device can be transmitted, and pulse control can be directly applied to the transmitting antenna with high electromagnetic induction through a common controller I/O interface, improving the reliability of the transmission system of the present application. can.

Specifically, the transmission system of the present application includes a control module 11 , a drive module 12 and an antenna excitation module 13 . The control module 11 is electrically connected to the driving module 12 , and the driving module 12 is electrically connected to the antenna excitation module 13 .

The control module 11 is used to receive a periodic pulse signal generated by a control command input from the controller I/O interface, the periodic pulse signal being a periodic voltage signal, a periodic voltage In the signal, the voltage amplitude value of the pulse signal changes regularly within one cycle, and the "high" voltage amplitude value of the pulse signal is the weight that occupies the entire cycle. If the case corresponds to high level, 0V corresponds to low level, the signal amplitude value in the period is not 5V, it is 0V, generally set the duty ratio to 50%, that is, "5V" and "0V '' respectively occupy half, the unit of the duty ratio is ``%'', the duty ratio is the proportion of time that the high level occupies in one period, where 5V is the high level. Therefore, the voltage amplitude value of the periodic pulse signal is 0V to 5V, the signal frequency is 3Hz to 30Hz, and the duty ratio is 50%.

As shown in FIG. 2, which is a circuit principle schematic diagram of the driving module 12 according to the embodiment of the present application, the driving module 12 includes a block capacitor Cb, a discharge resistor Rd, a first flyback diode Df, a gate resistor Rg, a gate source including resistance Rgs and gate voltage Vg,
Among them, as shown in FIG. 2, the input terminal for controlling the periodic pulse signal is connected in series with the block capacitor Cb, the gate resistor Rg, and the gate-source resistor Rgs in this order and then grounded to form a charging circuit. and the gate-source resistor Rgs, a gate voltage Vg output terminal is provided.

When the periodic pulse signal input to the input for controlling the periodic pulse signal is at a high potential voltage value, the charging circuit charges the block capacitor Cb and drives the high potential through the output of the gate voltage Vg. A voltage signal can be output. The high-potential voltage value is equal to or higher than the highest voltage value of the periodic pulse signal. For example, if the highest voltage value of the periodic pulse signal is 5V, the high-potential voltage value is 5V or higher. The signal is at a high potential voltage value, indicating that the charging circuit should charge the block capacitor Cb and output a 5V drive voltage signal through the gate voltage Vg output. If the input end for controlling the periodic pulse signal continuously inputs the periodic pulse signal with the high potential voltage value, the periodic pulse signal with the high potential voltage value is continuously input to the antenna excitation module 13, which needs to turn on the power switching transistor N-MOS continuously, so that after the charging circuit fully charges the blocking capacitor Cb, the output end of the gate voltage Vg is reduced to zero, so that the antenna excitation module It prevents the power switching transistor N-MOS at 13 from being turned on continuously. If the input end controlling the periodic pulse signal continuously inputs a high-potential voltage value, that is, "5V" continuously, the power switching transistor N-MOS must be continuously turned on. , the power switching transistor N-MOS will burn out the antenna if it is continuously turned on, so the present application can effectively avoid the occurrence of such situation by installing the charging circuit.

A discharge resistor Rd and a first flyback diode Df are further provided between the input terminal for controlling the periodic pulse signal and the ground, and the block capacitor Cb, the discharge resistor Rd and the first flyback diode Df are connected in series. constitutes a discharge circuit, when the periodic pulse signal is at a low potential voltage value, the discharge circuit discharges the block capacitor Cb and outputs a low potential driving voltage signal through the output terminal of the gate voltage Vg, The low potential voltage value is less than the highest voltage value of the periodic pulse signal. For example, if the highest voltage value of the periodic pulse signal is 5V, the low potential voltage value is less than 5V.

FIG. 3 is a circuit principle schematic diagram of the antenna excitation module 13 according to an embodiment of the present application. The antenna excitation module includes a power switching transistor N-MOS, a DC resistor, a second flyback diode Df, a first antenna port Vo1, It includes a second antenna port Vo2, a gate-source voltage output terminal Vgs and an antenna winding.

Here, as shown in FIG. 3, one side of the first antenna port Vo1 is connected to the power supply, and the other side is connected to the second antenna port Vo2 after the antenna winding and the DC resistance are connected in series in this order. , the gate-source voltage Vgs output terminal is connected to the gate g of the power switching transistor N-MOS, the drain d of the power switching transistor N-MOS is connected to the second antenna port Vo2, the source of the power switching transistor N-MOS s is grounded.

One side of the second flyback diode Df is connected between the first antenna port Vo1 and the antenna winding, the other side is connected between the DC resistor and the second antenna port Vo2, and the antenna winding, The DC resistor and the second flyback diode Df are connected in series to form a magnetic reset circuit, and when the power switching transistor N-MOS is turned off, the magnetic reset circuit reduces the excitation current in the antenna winding. can be done. Specifically, when the power switching transistor N-MOS is turned off, the magnetic reset circuit discharges the current of the antenna winding through the second flywheel diode Df and the DC resistance, and the specific discharge period is , to reduce the current in the antenna winding according to a first discharge period, the first discharge period being the ratio of the antenna inductance of the antenna winding to the DC resistance of the antenna winding, and the power switching transistor N - Only when the off period of the MOS is longer than the first discharge period can the current in the antenna winding be reduced in sufficient time. Here, the wire diameter of the enameled wire used for the antenna winding, the number of turns of the winding and the radius of the winding are directly proportional, and can be obtained by a lookup table, and the wire diameter of the antenna winding is the amperage requirement can be guaranteed to meet In the present application, the antenna winding can be selected with a smaller wire diameter, and under the premise that the number of turns of the winding and the magnetic core remain unchanged, the size of the antenna winding can be reduced by shortening the length of the magnetic core. Optimization can be achieved.

Specifically, the output terminal of the gate voltage Vg is electrically connected to the gate-source voltage Vgs, and the voltage value to which the driving voltage signal output from the output terminal of the gate voltage Vg is input is the voltage of the gate-source voltage Vgs. value, the voltage value of the gate-source voltage Vgs is determined by its own attributes. 7V, the power switching transistor N-MOS must be turned off and the current in the antenna winding reduced to zero by the magnetic reset circuit. Magnetic resetting of the antenna winding is thereby ensured.

The gate-source voltage Vgs output terminal is connected in series with the power switching transistor N-MOS, the second antenna port Vo2, the DC resistor, the antenna winding, and the first antenna port Vo1 to form an excitation circuit, and the excitation circuit is connected to the gate source. The output excitation current is controlled based on the voltage input to the voltage Vgs output terminal. Specifically, when the voltage value to which the driving voltage signal output from the output terminal of the gate voltage Vg is input is equal to or higher than the voltage value of the gate-source voltage Vgs, the voltage value of the gate-source voltage Vgs Generally, the voltage value of the gate-source voltage Vgs is 1.7V, and if the voltage value to which the driving voltage signal is input is 1.7V or higher, the power switching transistor N-MOS is turned on and excited. A magnetic sensing signal must be generated by the circuit.

As shown in FIG. 4, an embodiment of the present application further provides a method for transmitting an extremely low frequency magnetic sensing signal, the method including steps S101-S103 as follows.

In step S101, a periodic pulse signal, which is a periodic voltage signal, is generated based on the input command.

In step S102, drive voltage control is performed on the input periodic pulse signal to obtain a drive voltage signal.

In step S103, based on the input driving voltage signal, excitation adjustment control is performed to obtain a magnetic sensing signal used for transmission.

As shown in FIG. 5, embodiments of the present application further provide an apparatus for transmitting extremely low frequency magnetic sensing signals, the apparatus comprising:
a pulse signal port for inputting a periodic pulse signal;
a signal ground port for providing ground;
a power port for inputting a power supply voltage;
a first antenna port and a second antenna port;
a controller electrically connected to any of the pulse signal port, the signal ground port, the power port, the first antenna port and the second antenna port and having an extremely low frequency magnetic sensing signal transmission system disposed thereon.

According to the above technical configuration, the present application provides an extremely low frequency magnetic sensing signal transmission system, method and apparatus, which includes a control module, a driving module and an antenna excitation module. The control module is for generating a periodic pulse signal, which is a periodic voltage signal, based on the input command, and the drive module controls the drive voltage for the input periodic pulse signal. The antenna excitation module performs excitation adjustment control based on the input drive voltage signal to obtain the magnetic sensing signal used for transmission. According to the technical configuration of the present application, the problem of the transmission antenna induced electromotive force can be effectively solved, and the problem of voltage stress due to the transmission antenna induced electromotive force can also be solved.

The same or similar parts in each embodiment in this specification can be referred to each other, and duplicate descriptions will be omitted here.

Finally, it should be explained that the above embodiments are only for explaining the technical structure of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to each of the above embodiments, those skilled in the art may modify the technical configurations described in each of the above embodiments, or equivalently replace some or all of the technical features thereof. It should be understood that these modifications or replacements do not deviate from the scope of the technical solution of each embodiment of the present application from the essence of the corresponding technical configuration.

The above description, for convenience of explanation, is made with respect to specific embodiments. However, the exemplary discussion above is not intended to be exhaustive or to limit the embodiments to the particular forms disclosed above. Many modifications and variations are possible in light of the above teaching. The above selection and description of the embodiments better explain the principles and practical applications, thereby enabling those skilled in the art to better use the embodiments, and provide specifics of the various different variations contemplated. It is intended to be suitable for various uses.

Claims (9)

including a control module, a drive module, and an antenna excitation module;
The control module generates a periodic pulse signal, which is a periodic voltage signal, based on the input command;
The drive module performs drive voltage control on the input periodic pulse signal to obtain a drive voltage signal,
The antenna excitation module performs excitation adjustment control according to the input driving voltage signal to obtain a magnetic sensing signal used for transmission, and includes a power switching transistor, a DC resistor, a second flyback diode, and a first antenna port. , a second antenna port, a gate-source voltage output terminal and an antenna winding,
One side of the first antenna port is connected to a power supply, the other side is connected to the second antenna port after the antenna winding and the DC resistance are connected in series in this order, and the gate-source voltage output terminal is , connected to the gate of the power switching transistor, the drain of the power switching transistor being connected to the second antenna port, the source of the power switching transistor being grounded;
one side of the second flyback diode is connected between the first antenna port and the antenna winding, the other side is connected between the DC resistor and the second antenna port; The winding, the DC resistor, and the second flyback diode are connected in series to form a magnetic reset circuit, the magnetic reset circuit for controlling an excitation current in the antenna winding when the power switching transistor is turned off. to reduce
The gate-source voltage output terminal is connected in series with the power switching transistor, the second antenna port, the DC resistor, the antenna winding, and the first antenna port to form an excitation circuit, wherein the excitation circuit comprises the controlling the output excitation current based on the voltage input to the gate-source voltage output terminal;
An extremely low frequency magnetic sensing signal transmission system characterized by: the driving module includes a block capacitor, a discharge resistor, a first flyback diode, a gate resistor, a gate source resistor and a gate voltage;
The input terminal for controlling the periodic pulse signal is connected in series with the block capacitor, the gate resistor, and the gate-source resistor in this order and then grounded to form a charging circuit. A gate voltage output terminal is provided between the
The discharge resistor and the first flyback diode are further provided between the input terminal for controlling the periodic pulse signal and the ground,
The block capacitor, the discharge resistor and the first flyback diode are connected in series to form a discharge circuit, and the discharge circuit discharges the block capacitor when the periodic pulse signal is at a low potential voltage value. and outputting the driving voltage signal of low potential through the gate voltage output terminal, wherein the low potential voltage value is less than the highest voltage value of the periodic pulse signal,
The charging circuit charges the block capacitor when the periodic pulse signal is at a high potential voltage value, outputs the driving voltage signal at a high potential through the gate voltage output terminal, and outputs the high potential voltage value. is greater than or equal to the highest voltage value of the periodic pulse signal,
The transmission system for ultra-low frequency magnetic sensing signals according to claim 1, characterized in that: the charging circuit reduces the output of the gate voltage to zero when the input controlling the periodic pulse signal continuously receives the periodic pulse signal of high potential voltage value;
3. The transmission system for ultra-low frequency magnetic sensing signals according to claim 2, characterized in that: The periodic pulse signal has a voltage amplitude value of 0 V to 5 V, a signal frequency of 3 Hz to 30 Hz, and a duty ratio of 50%.
The transmission system for ultra-low frequency magnetic sensing signals according to claim 1, characterized in that: The magnetic reset circuit turns off the power switching transistor when the voltage value input to the drive voltage signal is less than the voltage value of the gate-source voltage, causing the current in the antenna winding to be zero by the magnetic reset circuit. lower the
The excitation circuit turns on the power switching transistor when the voltage value input to the drive voltage signal is greater than or equal to the voltage value of the gate-source voltage, and the excitation circuit generates the magnetic sensing signal.
The transmission system for ultra-low frequency magnetic sensing signals according to claim 1, characterized in that: The magnetic reset circuit discharges the current in the antenna winding when the power switching transistor is turned off, and reduces the current in the antenna winding according to a first discharge period, the first discharge period being , the ratio of the antenna inductance of the antenna winding to the DC resistance of the antenna winding, wherein the off period of the power switching transistor is longer than the first discharge period;
6. The transmission system for ultra-low frequency magnetic sensing signals according to claim 5, characterized in that: The wire diameter of the enameled wire used for the antenna winding, the number of turns of the winding and the radius of the winding are directly proportional,
The transmission system for ultra-low frequency magnetic sensing signals according to claim 1, characterized in that: An extremely low frequency magnetic sensing signal transmission method applied to the extremely low frequency magnetic sensing signal transmission system according to any one of claims 1 to 7,
generating a periodic pulse signal, which is a periodic voltage signal, based on the input command;
obtaining a drive voltage signal by performing drive voltage control on the input periodic pulse signal;
and obtaining a magnetic sensing signal used for transmission by performing excitation adjustment control based on the input driving voltage signal.
A method for transmitting an extremely low frequency magnetic sensing signal, characterized by: a pulse signal port for inputting a periodic pulse signal;
a signal ground port for providing ground;
a power port for inputting a power supply voltage;
a first antenna port and a second antenna port;
An extremely low frequency antenna according to any one of claims 1 to 7, electrically connected to any of said pulse signal port, said signal ground port, said power port, said first antenna port and said second antenna port. a controller in which a transmission system for frequency magnetic sensing signals is located;
An extremely low frequency magnetic sensing signal transmitter characterized by: