Power supply circuit and power supply equipment

Abstract

The invention discloses a power supply circuit and power supply equipment, and relates to the technical field of equipment power supply, and the power supply circuit comprises a rectification module, a filtering voltage stabilization module, an anti-reflux module, a current limiting module, a field effect transistor module and a control module. The control module detects the voltage of the field effect transistor module in real time and calculates the surge current in real time, it is ensured that the drain electrode of the field effect transistor module and the source electrode of the field effect transistor module can be conducted only when the surge current needs to be smaller than a preset threshold value and the voltage of the field effect transistor module is zero, and the control accuracy of the surge current is improved; and energy in the surge current is converted into storage charges for subsequent power supply through the filtering and voltage stabilizing module, so that direct consumption of energy is avoided, and the overall energy consumption is reduced. The technical problems of inaccuracy in surge current control and waste of excess energy in the surge process are solved, and the technical effects of effectively controlling the surge current and recycling the excess energy generated in the surge process are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of equipment power supply, and in particular to a power supply circuit and a power supply device. Background Art

[0002] When the power supply circuit is started, due to the presence of energy storage capacitors in the power supply circuit, a momentary inrush current (Inrush Current) is often generated. The inrush current usually reaches hundreds or even thousands of amperes, which may cause the input voltage to drop instantly, causing impact on other components in the power supply circuit, shortening their service life or even causing failures. At the same time, the inrush current not only affects the stability of the input voltage, but may also cause heat accumulation inside the system, thereby accelerating component aging. In addition, the inrush current will also interfere with surrounding sensitive equipment, especially in scenarios that require precise power management, such as communication equipment, industrial control systems, etc.

[0003] Therefore, how to effectively control the surge current and recover the excess energy generated during the surge process is a key issue in power supply circuit design. Summary of the invention

[0004] The present application provides a power supply circuit and a power supply device to at least solve the problem of effectively controlling surge current and recovering excess energy generated during the surge process in the related art.

[0005] The present application provides a power supply circuit, the power supply circuit comprising:

[0006] Rectifier module, the AC positive input terminal of the rectifier module is used to connect the positive pole of the AC power supply, and the AC negative input terminal of the rectifier module is used to connect the negative pole of the AC power supply;

[0007] A filtering and voltage stabilizing module, wherein the first end of the filtering and voltage stabilizing module is connected to the positive DC output end of the rectifier module; the first end of the filtering and voltage stabilizing module is also used to connect to the positive electrode of the load device to be powered;

[0008] An anti-backflow module, wherein the positive electrode of the anti-backflow module is connected to the negative DC output terminal of the rectifier module, and the negative electrode of the anti-backflow module is connected to the second terminal of the filter and voltage stabilization module;

[0009] A current limiting module, wherein the first end of the current limiting module is used to connect to the second end of the filtering and voltage stabilizing module, and the second end of the current limiting module is connected to the negative DC output end of the rectifier module;

[0010] A field effect tube module, wherein the source of the field effect tube module is connected to the first end of the current limiting module, and the drain of the field effect tube module is connected to the second end of the current limiting module; the drain of the field effect tube module is also used to connect to the positive electrode of the load device to be powered;

[0011] A control module, wherein the input end of the control module is connected to the second end of the filter and voltage regulator module, and the output end of the control module is connected to the gate of the field effect tube module; the control module is used to detect the voltage of the field effect tube module and calculate the surge current according to the voltage of the field effect tube module; the control module is also used to output a field effect tube module conduction control signal to the gate of the field effect tube module when the surge current is less than a preset threshold and the voltage of the field effect tube module is zero, so that the gate of the field effect tube module conducts the drain of the field effect tube module and the source of the field effect tube module when receiving the field effect tube module conduction control signal; wherein the field effect tube module voltage is the voltage between the drain of the field effect tube module and the source of the field effect tube module.

[0012] In one embodiment, the control module includes:

[0013] An analog-to-digital conversion unit, wherein a first end of the analog-to-digital conversion unit is connected to a second end of the filtering and voltage stabilizing module;

[0014] An inrush current calculation unit, wherein the first end of the inrush current calculation unit is connected to the second end of the analog-to-digital conversion unit, and the inrush current calculation unit is used to determine the voltage of the field effect tube module according to the digital electrical signal output by the analog-to-digital conversion unit; the inrush current calculation unit is also used to obtain the inrush current after calculation according to the voltage of the field effect tube module, the energy storage capacitor value of the filter and voltage stabilization module, and the preset unit time; the inrush current calculation unit is also used to output a first high voltage signal when the inrush current is less than a preset threshold value; the inrush current calculation unit is also used to output a first low voltage signal when the inrush current is greater than or equal to the preset threshold value;

[0015] A zero voltage detection unit, wherein the first end of the zero voltage detection unit is connected to the second end of the analog-to-digital conversion unit, and the zero voltage detection unit is used to determine the voltage of the field effect tube module according to the digital electrical signal; the zero voltage detection unit is also used to output a second high voltage signal when the voltage of the field effect tube module is zero; the zero voltage detection unit is also used to output a second low voltage signal when the voltage of the field effect tube module is non-zero;

[0016] A logic gate unit, wherein the first end of the logic gate unit is connected to the second end of the surge current calculation unit and the second end of the zero voltage detection unit, and the second end of the logic gate unit is connected to the gate of the field effect tube module; the logic gate unit is used to output a third low voltage signal when receiving the first high voltage signal and the second high voltage signal; the third low voltage signal is a conduction control signal of the field effect tube module.

[0017] In one embodiment, the logic gate unit includes:

[0018] An AND gate, wherein a first input terminal of the AND gate is connected to a second terminal of the surge current calculation unit, and a second input terminal of the AND gate is connected to a second terminal of the zero voltage detection unit.

[0019] A NOT gate, wherein a first end of the NOT gate is connected to an output end of the AND gate, and a second end of the NOT gate is connected to a gate of the field effect tube module.

[0020] In one embodiment, the inrush current is calculated based on the following expression:

[0021]

[0022] Where, I is the surge current; V mos is the voltage of the field effect tube module, C is the energy storage capacitor value of the filter and voltage regulator module; t is the preset unit time.

[0023] In one embodiment, the power supply circuit further includes an AC power source.

[0024] In one embodiment, the filtering and voltage stabilizing module is an energy storage capacitor.

[0025] In one embodiment, the backflow prevention module is a diode.

[0026] In one embodiment, the current limiting module includes a diode and a resistor; wherein the positive electrode of the diode is connected to the second end of the filtering and voltage stabilizing module, the negative electrode of the diode is connected to the first end of the resistor, and the second end of the resistor is connected to the negative DC output end of the rectifier module.

[0027] In one embodiment, the field effect transistor module is a metal-oxide semiconductor field effect transistor.

[0028] The present application provides a power supply device, comprising any power supply circuit in the above embodiments.

[0029] Through this application, the charging process of the power supply circuit is as follows: the partial DC signal output after the AC power signal of the AC power source is rectified by the rectifier module flows to the filter voltage regulator module for charging, and then flows through the current limiting module to limit the surge current and then returns to the negative DC output terminal of the rectifier module. In addition, the partial DC signal output after the AC power signal of the AC power source is rectified by the rectifier module flows directly to the positive electrode of the load device to be powered for power supply, and flows back from the negative electrode of the load device to be powered to the negative DC output terminal of the rectifier module. At the same time, the control module detects the voltage of the field effect tube module, that is, the voltage between the drain of the field effect tube module and the source of the field effect tube module, and calculates the surge current according to the voltage of the field effect tube module. Therefore, through the coordinated work of the current limiting module and the field effect tube module, the effective suppression of the surge current and the improvement of the charging efficiency are achieved, the reliability of the power supply circuit is improved, the power supply circuit has a simple structure and flexible application, and is suitable for a variety of scenarios requiring surge current control. When the surge current is less than the preset threshold and the voltage of the field effect tube module is zero, the control module outputs a field effect tube module conduction control signal to the gate of the field effect tube module, so that the gate of the field effect tube module conducts the drain of the field effect tube module and the source of the field effect tube module when receiving the field effect tube module conduction control signal, and the discharge process of the above-mentioned power supply circuit is started. The discharge process of the above-mentioned power supply circuit is as follows: after the filter and voltage regulator module is discharged, a DC signal is formed, which flows through the drain of the field effect tube module, the source of the field effect tube module, the positive electrode of the anti-backflow module, the negative electrode of the anti-backflow module, the second end of the filter and voltage regulator module, and the first end of the filter and voltage regulator module to the positive electrode of the load device to be powered for power supply. In addition, part of the DC signal output after the AC power signal of the AC power source is rectified by the rectifier module directly flows to the positive electrode of the load device to be powered for power supply, and flows back from the negative electrode of the load device to be powered to the negative DC output end of the rectifier module.Therefore, the power supply circuit detects the voltage of the field effect tube module and calculates the surge current in real time through the control module, ensuring that the drain of the field effect tube module and the source of the field effect tube module can be turned on only when the surge current is less than the preset threshold and the voltage of the field effect tube module is zero. That is, the peak value of the surge current is effectively reduced through the coordinated work of the current limiting module and the dynamically turned-on field effect tube module, thereby improving the control accuracy of the surge current; then, by setting the surge current to be less than the preset threshold as one of the turn-on conditions for the turn-on field effect tube module, it is ensured that the surge current is always within a safe range, avoiding excessive transient current from damaging components in the power supply circuit, and extending the power supply period. The life of components in the power circuit is extended, the maintenance frequency of the power supply circuit is reduced, and the reliability and availability of the power supply circuit are improved; then, by setting the field effect tube module voltage to zero as one of the conduction conditions for turning on the field effect tube module, the surge current is avoided from being increased due to misjudgment, the switching loss of the field effect tube module is reduced, and the stability of the power supply circuit operation is improved; then, the unidirectionality and safety of the surge energy recovery process are ensured through the anti-reverse current module to avoid the damage of the reverse current to the power supply circuit; at the same time, the energy in the surge current is converted into stored charge through the filtering and voltage stabilizing module for subsequent power supply, avoiding direct energy consumption and reducing overall energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A first schematic diagram of a power supply circuit provided in an embodiment of the present application;

[0032] Figure 2 A second schematic diagram of a power supply circuit provided in an embodiment of the present application;

[0033] Figure 3 A third schematic diagram of a power supply circuit provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of a logic gate unit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] It should be noted that, in the description of this application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0037] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0038] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] The present application provides a power supply circuit, such as Figure 1 As shown, it is characterized in that the power supply circuit includes a rectifier module 100, a filter and voltage stabilization module 200, an anti-backflow module 300, a current limiting module 400, a field effect tube module 500 and a control module 600.

[0040] Among them, the AC positive input terminal of the rectification module 100 is used to connect to the positive pole of the AC power supply, and the AC negative input terminal of the rectification module 100 is used to connect to the negative pole of the AC power supply; the first end of the filter voltage stabilization module 200 is connected to the positive DC output terminal of the rectification module 100; the first end of the filter voltage stabilization module 200 is also used to connect to the positive pole of the load device to be powered; the positive pole of the anti-backflow module 300 is connected to the negative DC output terminal of the rectification module 100, and the negative pole of the anti-backflow module 300 is connected to the second end of the filter voltage stabilization module 200; the first end of the current limiting module 400 is used to connect to the second end of the filter voltage stabilization module 200, and the second end of the current limiting module is connected to the negative DC output terminal of the rectification module 100; the source electrode of the field effect transistor module 500 is connected to the first end of the current limiting module 400, and the drain electrode of the field effect transistor module 500 is connected to the second end of the current limiting module 400; the drain electrode of the field effect transistor module 500 is also used to connect to the positive pole of the load device to be powered; the input terminal of the control module 600 is connected to the second end of the filter voltage stabilization module 200, and the output terminal of the control module 100 is connected to the gate electrode of the field effect transistor module 500.

[0041] The rectification module 100 is a module or device that can rectify the input AC signal and output a DC signal. In one embodiment, the rectification module 100 is a rectifier bridge.

[0042] The filter voltage stabilization module 200 is a module or device that can filter and stabilize the input DC signal. It can be understood that the voltage output can be stabilized through the filter voltage stabilization module. In one embodiment, the filter voltage stabilization module 200 is an energy storage capacitor.

[0043] The anti-backflow module 300 is a module or device that can prevent current backflow. In one embodiment, the anti-backflow module is a diode.

[0044] The current limiting module 400 is a module or device that can limit the magnitude of the current. In one embodiment, as Figure 2 shown, the current limiting module 400 includes a diode 410 and a resistor 420; wherein, the positive pole of the diode 410 is connected to the second end of the filter voltage stabilization module 200, the negative pole of the diode 410 is connected to the first end of the resistor, and the second end of the resistor 420 is connected to the negative DC output terminal of the rectification module 100.

[0045] The field effect transistor module 500 is a module or device that can control the current in the output circuit by controlling the electric field effect in the input circuit. The field effect transistor module 500 has the advantages of high input resistance, low noise, low power consumption, large dynamic range, easy integration, etc. In one embodiment, the field effect transistor module 500 is a metal-oxide semiconductor field effect transistor (MOS-FET).

[0046] The control module 600 is used to detect the field effect tube module voltage and calculate the surge current based on the field effect tube module voltage; the control module 600 is also used to output a field effect tube module conduction control signal to the gate of the field effect tube module 500 when the surge current is less than a preset threshold and the field effect tube module voltage is zero, so that the gate of the field effect tube module 500 conducts the drain of the field effect tube module 500 and the source of the field effect tube module 500 when receiving the field effect tube module conduction control signal; wherein the field effect tube module voltage is the voltage between the drain of the field effect tube module 500 and the source of the field effect tube module 500.

[0047] It can be understood that the charging process of the above-mentioned power supply circuit is as follows: the part of the DC signal output after the AC power signal of the AC power source is rectified by the rectifier module 100 flows to the filter voltage regulator module 200 for charging, and then flows through the current limiting module 400 to limit the surge current and then returns to the negative DC output terminal of the rectifier module 100. In addition, the part of the DC signal output after the AC power signal of the AC power source is rectified by the rectifier module 100 flows directly to the positive electrode of the load device to be powered for power supply, and flows back from the negative electrode of the load device to be powered to the negative DC output terminal of the rectifier module 100. At the same time, the control module 500 detects the voltage of the field effect tube module, that is, the voltage between the drain of the field effect tube module 500 and the source of the field effect tube module 500, and calculates the surge current according to the voltage of the field effect tube module. Therefore, through the coordinated work of the current limiting module 400 and the field effect tube module 500, the surge current is effectively suppressed and the charging efficiency is improved, the reliability of the power supply circuit is improved, the power supply circuit has a simple structure and flexible application, and is suitable for a variety of scenarios requiring surge current control.

[0048] It can be understood that the control module 500 outputs a field effect tube module conduction control signal to the gate of the field effect tube module 500 when the surge current is less than the preset threshold and the field effect tube module voltage is zero, so that the gate of the field effect tube module 500 conducts the drain of the field effect tube module 500 and the source of the field effect tube module 500 when receiving the field effect tube module conduction control signal, thereby starting the discharge process of the above-mentioned power supply circuit.

[0049] It can be understood that the discharge process of the above power supply circuit is: after the filter and voltage regulator module 200 is discharged, a DC signal is formed, which flows through the drain of the field effect tube module 500, the source of the field effect tube module 500, the positive electrode of the anti-backflow module 300, the negative electrode of the anti-backflow module 300, the second end of the filter and voltage regulator module 200, and the first end of the filter and voltage regulator module 200 to the positive electrode of the load device to be powered for power supply. In addition, after the AC power signal of the AC power source is rectified by the rectifier module 100, part of the DC signal output directly flows to the positive electrode of the load device to be powered for power supply, and flows back from the negative electrode of the load device to be powered to the negative DC output end of the rectifier module 100.

[0050] Based on this, the power supply circuit detects the voltage of the field effect tube module and calculates the surge current in real time through the control module 600, ensuring that the drain of the field effect tube module 500 and the source of the field effect tube module 500 can be turned on only when the surge current is less than the preset threshold and the voltage of the field effect tube module is zero. That is, the peak value of the surge current is effectively reduced through the coordinated work of the current limiting module 400 and the dynamically turned-on field effect tube module 500, thereby improving the control accuracy of the surge current. Then, by setting the surge current to be less than the preset threshold as one of the turn-on conditions for turning on the field effect tube module 500, it is ensured that the surge current is always within a safe range, avoiding excessive transient current from damaging components in the power supply circuit, and extending the life of the power supply circuit. The service life of the components in the power supply circuit is prolonged, the maintenance frequency of the power supply circuit is reduced, and the reliability and availability of the power supply circuit are improved; then, by setting the field effect tube module voltage to zero as one of the conduction conditions for turning on the field effect tube module 500, it is avoided that the surge current increases due to misjudgment, the switching loss of the field effect tube module 500 is reduced, and the stability of the power supply circuit operation is improved; then, the anti-reverse current module 300 is used to ensure the unidirectionality and safety of the surge energy recovery process, and the damage to the power supply circuit by the reverse current is avoided; at the same time, the energy in the surge current is converted into stored charge through the filtering and voltage stabilizing module 200 for subsequent power supply, thereby avoiding direct energy consumption and reducing overall energy consumption.

[0051] In one embodiment, if Figure 3 As shown, the control module 600 includes an analog-to-digital conversion unit 610 , an inrush current calculation unit 620 , a zero voltage detection unit 630 and a logic gate unit 640 .

[0052] Among them, the first end of the analog-to-digital conversion unit 610 is connected to the second end of the filtering and voltage stabilizing module 200; the first end of the surge current calculation unit 620 is connected to the second end of the analog-to-digital conversion unit 610; the first end of the zero voltage detection unit 630 is connected to the second end of the analog-to-digital conversion unit 620; the first end of the logic gate unit 640 is connected to the second end of the surge current calculation unit 620 and the second end of the zero voltage detection unit 630, and the second end of the logic gate unit 640 is connected to the gate of the field effect tube module 500;

[0053] Specifically, the surge current calculation unit 620 is used to determine the voltage of the field effect tube module according to the digital electrical signal output by the analog-to-digital conversion unit; the surge current calculation unit 620 is also used to obtain the surge current after calculation according to the voltage of the field effect tube module, the energy storage capacitor value of the filter and voltage stabilization module 200 and the preset unit time; the surge current calculation unit 620 is also used to output a first high voltage signal when the surge current is less than a preset threshold value; the surge current calculation unit 620 is also used to output a first low voltage signal when the surge current is greater than or equal to the preset threshold value;

[0054] Specifically, the zero voltage detection unit 630 is used to determine the voltage of the field effect tube module according to the digital electrical signal; the zero voltage detection unit 630 is also used to output a second high voltage signal when the voltage of the field effect tube module is zero; the zero voltage detection unit 630 is also used to output a second low voltage signal when the voltage of the field effect tube module is non-zero;

[0055] Specifically, the logic gate unit 640 is used to output a third low voltage signal when receiving the first high voltage signal and the second high voltage signal; the third low voltage signal is a field effect tube module conduction control signal.

[0056] In this embodiment, the surge current control and zero voltage switching are combined through the above-mentioned control module 600, which effectively reduces the loss during the startup of the power supply circuit, so that the conduction of the field effect tube module 500 is quickly switched from the high-impedance current limiting mode to the low-impedance working mode, shortening the stabilization time, improving the overall working efficiency of the power supply circuit, and reducing the startup energy loss.

[0057] In one embodiment, if Figure 4 As shown, the logic gate unit 640 includes an AND gate 641 and a NOT gate 642 .

[0058] The first input end of the AND gate 641 is connected to the second end of the surge current calculation unit 620, and the second input end of the AND gate 641 is connected to the second end of the zero voltage detection unit 630. The first end of the NOT gate 642 is connected to the output end of the AND gate 641, and the second end of the NOT gate 642 is connected to the gate of the field effect tube module 500.

[0059] In this embodiment, the control efficiency of the field effect transistor module 500 is improved by using the logic gate unit 640 including the AND gate 641 and the NOT gate 642 .

[0060] In one embodiment, the inrush current is calculated based on the following expression:

[0061]

[0062] Where, I is the surge current; V mos is the voltage of the field effect tube module, C is the energy storage capacitor value of the filter and voltage regulator module; t is the preset unit time.

[0063] In one embodiment, the power supply circuit further includes an AC power source.

[0064] The present application provides a power supply device, comprising any power supply circuit in the above embodiments.

[0065] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0066] The above is a detailed introduction to a power supply circuit and a power supply device provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A power supply circuit, characterized in that: The power supply circuit comprises: A rectifier module, wherein the AC positive input terminal of the rectifier module is used to connect to the positive pole of the AC power supply, and the AC negative input terminal of the rectifier module is used to connect to the negative pole of the AC power supply; A filtering and voltage stabilizing module, wherein the first end of the filtering and voltage stabilizing module is connected to the positive DC output end of the rectifier module; the first end of the filtering and voltage stabilizing module is also used to connect to the positive electrode of the load device to be powered; A backflow prevention module, wherein the positive electrode of the backflow prevention module is connected to the negative DC output terminal of the rectifier module, and the negative electrode of the backflow prevention module is connected to the second end of the filtering and voltage stabilizing module; A current limiting module, wherein the first end of the current limiting module is used to connect to the second end of the filtering and voltage stabilizing module, and the second end of the current limiting module is connected to the negative DC output end of the rectifying module; A field effect tube module, wherein the source of the field effect tube module is connected to the first end of the current limiting module, and the drain of the field effect tube module is connected to the second end of the current limiting module; the drain of the field effect tube module is also used to connect to the positive electrode of the load device to be powered; A control module, wherein the input end of the control module is connected to the second end of the filtering and voltage stabilizing module, and the output end of the control module is connected to the gate of the field effect tube module; the control module is used to detect the voltage of the field effect tube module and calculate the surge current according to the voltage of the field effect tube module; the control module is also used to output a field effect tube module conduction control signal to the gate of the field effect tube module when the surge current is less than a preset threshold and the voltage of the field effect tube module is zero, so that the gate of the field effect tube module conducts the drain of the field effect tube module and the source of the field effect tube module when receiving the field effect tube module conduction control signal; wherein the field effect tube module voltage is the voltage between the drain of the field effect tube module and the source of the field effect tube module.

2. The power supply circuit according to claim 1, characterized in that: The control module comprises: An analog-to-digital conversion unit, wherein a first end of the analog-to-digital conversion unit is connected to a second end of the filtering and voltage stabilizing module; An inrush current calculation unit, wherein the first end of the inrush current calculation unit is connected to the second end of the analog-to-digital conversion unit, and the inrush current calculation unit is used to determine the voltage of the field effect tube module according to the digital electrical signal output by the analog-to-digital conversion unit; the inrush current calculation unit is also used to obtain the inrush current after calculation according to the voltage of the field effect tube module, the energy storage capacitor value of the filtering and voltage stabilizing module, and a preset unit time; the inrush current calculation unit is also used to output a first high voltage signal when the inrush current is less than the preset threshold value; the inrush current calculation unit is also used to output a first low voltage signal when the inrush current is greater than or equal to the preset threshold value; A zero voltage detection unit, wherein the first end of the zero voltage detection unit is connected to the second end of the analog-to-digital conversion unit, and the zero voltage detection unit is used to determine the voltage of the field effect tube module according to the digital electrical signal; the zero voltage detection unit is also used to output a second high voltage signal when the voltage of the field effect tube module is zero; the zero voltage detection unit is also used to output a second low voltage signal when the voltage of the field effect tube module is non-zero; A logic gate unit, wherein the first end of the logic gate unit is connected to the second end of the surge current calculation unit and the second end of the zero voltage detection unit, and the second end of the logic gate unit is connected to the gate of the field effect tube module; the logic gate unit is used to output a third low voltage signal when receiving the first high voltage signal and the second high voltage signal; the third low voltage signal is a conduction control signal of the field effect tube module.

3. The power supply circuit according to claim 2, characterized in that: The logic gate unit comprises: An AND gate, wherein a first input terminal of the AND gate is connected to a second terminal of the surge current calculation unit, and a second input terminal of the AND gate is connected to a second terminal of the zero voltage detection unit. A NOT gate, wherein a first end of the NOT gate is connected to the output end of the AND gate, and a second end of the NOT gate is connected to the gate of the field effect tube module.

4. The power supply circuit according to claim 2, characterized in that: The inrush current is calculated based on the following expression: Wherein, I is the surge current; V mos is the voltage of the field effect tube module, C is the energy storage capacitor value of the filtering and voltage stabilizing module; t is the preset unit time.

5. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes the AC power supply.

6. The power supply circuit according to claim 1, characterized in that: The filtering and voltage stabilizing module is an energy storage capacitor.

7. The power supply circuit according to claim 1, characterized in that: The anti-backflow module is a diode.

8. The power supply circuit according to claim 1, characterized in that: The current limiting module includes a diode and a resistor; wherein the positive electrode of the diode is connected to the second end of the filtering and voltage stabilizing module, the negative electrode of the diode is connected to the first end of the resistor, and the second end of the resistor is connected to the negative DC output end of the rectifier module.

9. The power supply circuit according to claim 1, characterized in that: The field effect transistor module is a metal-oxide semiconductor field effect transistor.

10. A power supply device, characterized in that: The invention comprises a power supply circuit according to any one of claims 1 to 9.

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