Flyback switching power supply surge current suppression device

Abstract

The utility model provides a surge current suppression device for a flyback switching power supply. The surge current suppression device comprises a bridge rectifier circuit, a surge current suppression circuit, a filter circuit, a starting circuit, an IC power supply circuit, a main power conversion circuit, a peak absorption circuit, a voltage stabilization feedback circuit and an output rectifier filter circuit, the input end of the bridge rectifier circuit is connected with commercial power, and the surge current suppression circuit is connected with the output end of the bridge rectifier circuit and the filter circuit; the starting circuit is respectively connected with the surge current suppression circuit and the main power conversion circuit; the IC power supply circuit is connected with the main power conversion circuit; the main power conversion circuit is connected with the peak absorption circuit and the IC power supply circuit; the voltage stabilization feedback circuit is connected with the main power conversion circuit and the output rectification filter circuit. According to the utility model, the surge current suppression circuit is always effective.

Description

Technical Field

[0001] The utility model belongs to the technical field of suppressing surge current, and in particular relates to a device for suppressing surge current of a flyback switching power supply. Background Art

[0002] Since the mains electricity is AC, it needs to be rectified and filtered to get a stable and smooth DC voltage. In order to obtain a DC voltage with a small enough ripple to supply the switch circuit, a large-capacity electrolytic capacitor is required for filtering. When the output power is greater, the filter capacitor capacity needs to be larger, and the larger the capacitor capacity, the greater the energy stored inside it, which will generate a very high surge current at the moment of power-on. This surge current is usually more than 100 times larger than when the switching power supply is working normally, which has a greater impact on the mains power grid and the air switch at the source, and often causes the air switch to trip or fail to close. At this time, it is necessary to set a circuit to suppress the surge current in the switching power supply to prevent the switching power supply from having adverse effects on the grid and the air switch. The current traditional method is generally to connect a thermistor NTC in series, but this circuit has certain defects: 1. When the thermistor NTC is switched on and off continuously for a short time, the temperature of the NTC body cannot drop to the normal temperature value in a short time (according to the specification, the resistance of NTC-2.5D-13 is 2.5Ω at 25℃, and the resistance is 0.5Ω at 90℃, which is a difference of 5 times). At this time, if the circuit is turned on, the thermistor NTC will lose the function of suppressing surge current. 2. The heat is large. From the working principle of the thermistor, it can be seen that when working, its body temperature will exceed 100℃, generating a lot of heat, causing the overall temperature of the switching power supply to rise and the life span to decrease. Utility Model Content

[0003] In order to overcome the above technical defects, the utility model provides a flyback switching power supply surge current suppression device, which can suppress surge current.

[0004] The utility model is realized by the following scheme:

[0005] A surge current suppression device, comprising: a bridge rectifier circuit, a surge current suppression circuit, a filter circuit, a start-up circuit, an IC power supply circuit, a main power conversion circuit, a peak absorption circuit, a voltage stabilization feedback circuit, and an output rectifier filter circuit;

[0006] The input end of the bridge rectifier circuit is connected to the mains, and the surge current suppression circuit is connected to the output end of the bridge rectifier circuit and the filter circuit;

[0007] The startup circuit is respectively connected to the surge current suppression circuit and the main power conversion circuit;

[0008] The IC power supply circuit is connected to the main power conversion circuit;

[0009] The main power conversion circuit is connected to the peak absorption circuit and the IC power supply circuit;

[0010] The voltage stabilizing feedback circuit is connected to the main power conversion circuit and the output rectifying and filtering circuit.

[0011] As a further improvement of the utility model, the bridge rectifier circuit comprises: a first diode, a second diode, a third diode and a fourth diode;

[0012] The anode of the first diode is connected to the positive pole of the mains, the cathode of the first diode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the fourth diode, and the anode of the second diode is connected to the negative pole of the mains;

[0013] A cathode of the third diode is connected to an anode of the first diode, and an anode of the third diode is connected to an anode of the fourth diode.

[0014] As a further improvement of the utility model, the surge current suppression circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first MOS tube, and a first electrolytic capacitor;

[0015] The positive electrode of the bridge rectifier circuit is connected to the negative electrode of the bridge rectifier circuit through the first resistor, the second resistor, and the first electrolytic capacitor;

[0016] The third resistor is connected in parallel with the first electrolytic capacitor;

[0017] The positive electrode of the bridge rectifier circuit is connected to the negative electrode of the bridge rectifier circuit through the filter circuit and the first MOS tube;

[0018] The gate of the first MOS tube is connected to the negative electrode of the bridge rectifier circuit through the first electrolytic capacitor;

[0019] Two ends of the fourth resistor are respectively connected to the drain and source of the first MOS tube.

[0020] As a further improvement of the present utility model, the startup circuit includes: a fifth resistor and a sixth resistor;

[0021] The inrush current suppression circuit is connected to the main power conversion circuit via the fifth resistor and the sixth resistor.

[0022] As a further improvement of the utility model, the peak absorption circuit includes: a fifth diode, a seventh resistor, and a first capacitor;

[0023] The inrush current suppression circuit is connected to the main power conversion circuit via the first capacitor and the reverse-conducting fifth diode; the seventh resistor is connected in parallel with the fifth diode.

[0024] As a further improvement of the utility model, the IC power supply circuit includes: an eighth resistor, a sixth diode and a third electrolytic capacitor;

[0025] The main power conversion circuit is grounded through the eighth resistor, the sixth diode, and the third electrolytic capacitor.

[0026] As a further improvement of the utility model, the main power conversion circuit includes: a main conversion circuit control chip, a ninth resistor, a tenth resistor, a second MOS tube, a transformer, and an eleventh resistor;

[0027] The main conversion circuit control chip is grounded through the ninth resistor;

[0028] The main conversion circuit control chip is grounded through the tenth resistor and the eleventh resistor;

[0029] The main conversion circuit control chip is connected to the drain of the second MOS tube through the tenth resistor;

[0030] The main conversion circuit control chip is connected to the gate of the second MOS tube;

[0031] The source of the second MOS tube is connected to the peak absorption circuit;

[0032] One end of the first winding of the transformer is connected to the positive electrode of the bridge rectifier circuit, and the other end is connected to the source electrode of the second MOS tube;

[0033] One end of the second winding of the transformer is connected to the IC power supply circuit, and the other end is grounded;

[0034] The third winding of the transformer is connected to the output rectification and filtering circuit.

[0035] As a further improvement of the utility model, the voltage stabilizing feedback circuit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a three-terminal voltage regulator, and an optical coupler;

[0036] The first end of the optical coupler is grounded, the second end is connected to the main power conversion circuit, and the second end, the third end, and the fourth end are connected to the fourteenth resistor;

[0037] The third end of the optical coupler is connected to the output rectification and filtering circuit through the thirteenth resistor;

[0038] The fourth end of the optical coupler is connected to the output rectification and filtering circuit through the second capacitor and the fifteenth resistor;

[0039] The third capacitor, the sixteenth resistor and the second capacitor are connected in parallel;

[0040] The fourth terminal of the optical coupler is connected to the output rectifier and filter circuit through the three-terminal voltage regulator and the fifteenth resistor;

[0041] The fourth terminal of the optical coupler is connected to the output rectifier and filter circuit through the three-terminal voltage regulator tube and the fourth capacitor;

[0042] The fourth terminal of the optical coupler is connected to the output rectification and filtering circuit through the three-terminal voltage regulator and the twelfth resistor.

[0043] As a further improvement of the utility model, the output rectification and filtering circuit includes: a seventh diode and a fourth electrolytic capacitor;

[0044] The anode of the seventh diode is connected to the main power conversion circuit, and the cathode is connected to the voltage stabilization feedback circuit through the fourth electrolytic capacitor;

[0045] Both ends of the fourth electrolytic capacitor serve as outputs.

[0046] Compared with the prior art, the beneficial effects of the utility model are as follows: by setting up an inrush current suppression circuit to achieve inrush current suppression, there is no need to use a thermistor NTC, thereby reducing the temperature rise of the switching power supply and achieving the purpose of increasing the life of the switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings, wherein:

[0048] Figure 1 The utility model is a schematic diagram of the overall structure of the flyback switching power supply surge current suppression device.

[0049] Figure numerals: 1. Bridge rectifier circuit; 2. Surge current suppression circuit; 3. Filter circuit; 4. Start-up circuit; 5. IC power supply circuit; 6. Main power conversion circuit; 7. Peak absorption circuit; 8. Voltage stabilization feedback circuit; 9. Output rectifier filter circuit. DETAILED DESCRIPTION

[0050] It should be clear that 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 the embodiments of the present application.

[0051] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0052] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0053] The utility model provides a flyback switching power supply surge current suppression device, such as Figure 1 As shown, it includes: a bridge rectifier circuit 1, an inrush current suppression circuit 2, a filter circuit 3, a start-up circuit 4, an IC power supply circuit 5, a main power conversion circuit 6, a peak absorption circuit 7, a voltage stabilization feedback circuit 8, and an output rectifier filter circuit 9; the input end of the bridge rectifier circuit 1 is connected to the mains, the inrush current suppression circuit 2 is connected to the output end of the bridge rectifier circuit 1, the filter circuit 3 and the start-up circuit 4 are respectively connected to the inrush current suppression circuit and the main power conversion circuit 6; the IC power supply circuit 5 is connected to the main power conversion circuit 6; the main power conversion circuit 6 is connected to the peak absorption circuit 7 and the IC power supply circuit 5; the voltage stabilization feedback circuit 8 is connected to the main power conversion circuit 6 and the output rectifier filter circuit 9. Among them, the filter circuit 3 can be implemented by a second electrolytic capacitor EC2.

[0054] As one embodiment, the bridge rectifier circuit 1 includes: a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; the anode of the first diode D1 is connected to the positive pole of the AC power, the cathode of the first diode D1 is connected to the cathode of the second diode D2, the anode of the second diode D2 is connected to the cathode of the fourth diode D4, and the anode of the second diode D2 is connected to the negative pole of the AC power; the cathode of the third diode D3 is connected to the anode of the first diode D1, and the anode of the third diode D3 is connected to the anode of the fourth diode D4.

[0055] Furthermore, the surge current suppression circuit 2 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first MOS tube Q1, and a first electrolytic capacitor EC1; the positive electrode of the bridge rectifier circuit 1 is connected to the negative electrode of the bridge rectifier circuit 1 through the first resistor R1, the second resistor R2, and the first electrolytic capacitor EC1; the third resistor R3 is connected to the first electrolytic capacitor EC1 in parallel; the positive electrode of the bridge rectifier circuit 1 is connected to the negative electrode of the bridge rectifier circuit 1 through the filter circuit 3 and the first MOS tube Q1; the gate of the first MOS tube Q1 is connected to the negative electrode of the bridge rectifier circuit 1 through the first electrolytic capacitor EC1; and the two ends of the fourth resistor R4 are respectively connected to the drain and source of the first MOS tube Q1.

[0056] The start-up circuit 4 includes: a fifth resistor R5 and a sixth resistor R6 ; the inrush current suppression circuit 2 is connected to the main power conversion circuit 6 via the fifth resistor R5 and the sixth resistor R6 .

[0057] The peak absorption circuit 7 includes: a fifth diode D6, a seventh resistor R7, and a first capacitor C1; the surge current suppression circuit 2 is connected to the main power conversion circuit 6 via the first capacitor C1 and the reverse-conducting fifth diode D5; the seventh resistor R7 is connected in parallel with the fifth diode D5.

[0058] The IC power supply circuit 5 includes: an eighth resistor R8, a sixth diode D6 and a third electrolytic capacitor EC3; the main power conversion circuit 6 is grounded through the eighth resistor R8, the sixth diode D6 and the third electrolytic capacitor EC3.

[0059] The main power conversion circuit 6 includes: a main conversion circuit control chip U1, a ninth resistor R9, a tenth resistor R10, a second MOS transistor Q2, a transformer T1, and an eleventh resistor R11; the main conversion circuit control chip U1 is grounded through the ninth resistor R9; the main conversion circuit control chip U1 is grounded through the tenth resistor R10 and the eleventh resistor R11; the main conversion circuit control chip U1 is connected to the drain of the second MOS transistor Q2 through the tenth resistor R10; the main conversion circuit control chip U1 is connected to the gate of the second MOS transistor Q2; the source of the second MOS transistor Q2 is connected to the peak absorption circuit 7; one end of the first winding of the transformer T1 is connected to the positive electrode of the bridge rectifier circuit 1, and the other end is connected to the source of the second MOS transistor Q2; one end of the second winding of the transformer T1 is connected to the IC power supply circuit 5, and the other end is grounded; the third winding of the transformer T1 is connected to the output rectifier filter circuit 9.

[0060] The voltage stabilizing feedback circuit 8 includes: a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a three-terminal voltage regulator U3, and an optical coupler U2; the first end of the optical coupler U2 is grounded, the second end is connected to the main power conversion circuit 6, and the second end, the third end, and the fourth end are connected to the fourteenth resistor R14; the third end of the optical coupler U2 is connected to the output rectifier filter circuit 9 through the thirteenth resistor R13; the optical coupler U2 The fourth end of the optocoupler U2 is connected to the output rectifier and filter circuit 9 through the second capacitor C2 and the fifteenth resistor R15; the third capacitor C3 and the sixteenth resistor R16 are connected in parallel with the second capacitor C2; the fourth end of the optocoupler U2 is connected to the output rectifier and filter circuit 9 through the three-terminal voltage regulator U3 and the fifteenth resistor R15; the fourth end of the optocoupler U2 is connected to the output rectifier and filter circuit 9 through the three-terminal voltage regulator U3 and the fourth capacitor C4; the fourth end of the optocoupler U2 is connected to the output rectifier and filter circuit 9 through the three-terminal voltage regulator U3 and the twelfth resistor R12.

[0061] The output rectification and filtering circuit 9 includes: a seventh diode D7 and a fourth electrolytic capacitor EC4; the positive electrode of the seventh diode D7 is connected to the voltage stabilizing feedback circuit 8, and the negative electrode is connected to the main power conversion circuit 6 through the fourth electrolytic capacitor EC4; both ends of the fourth electrolytic capacitor EC4 serve as outputs.

[0062] Next, the utility model is further explained in conjunction with the specific implementation process, as follows:

[0063] The AC mains is rectified into a pulsating DC voltage through a rectifier bridge (first diode D1-fourth diode D4), and then passes through a surge current suppression circuit 2 composed of a first MOS tube Q1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a first electrolytic capacitor EC1 to control the surge current of the loop, and then is filtered by the second electrolytic capacitor EC2 (filter circuit 3) to become a smooth DC voltage, and then supplied to a start-up circuit 4 composed of a fifth resistor R5 and a sixth resistor R6 to power the main conversion circuit control chip U1. The main conversion circuit control chip U1 starts to work after being powered, and outputs a PWM voltage to drive the second MOS tube Q2 to turn on. The DC power supply current passes through the transformer T1 and the second MOS tube Q2 and then returns to the negative electrode of the DC power supply to form a loop. At this time, the transformer power supply winding induces a voltage to power the main conversion circuit control chip U1 through the eighth resistor R8, the sixth diode D6, and the third electrolytic capacitor EC3. The peak absorption circuit 7 composed of the fifth diode D5, the seventh resistor R7, and the first capacitor C1 protects the second MOS tube Q2 from being damaged by the peak voltage. The twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, the optocoupler U2, the three-terminal voltage regulator U3, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 form a voltage stabilization feedback circuit 8 to ensure the stability of the output voltage. The rectifier filter circuit 3 composed of the seventh diode D7 and the fourth electrolytic capacitor EC4 converts the output pulsating voltage into a smooth DC low-voltage output.

[0064] The 220V 50Hz AC mains is rectified into a 100Hz pulsating DC voltage through a rectifier bridge (first diode D1-fourth diode D4), and filtered into a smooth DC voltage by the second electrolytic capacitor EC2. The filter electrolytic capacity of a high-power power supply is relatively large, and the electrolytic capacitor is equivalent to a short circuit at the moment of charging, which will form a very large surge current in the circuit. When multiple power supplies are used at the same time, a very high surge current will be generated at the moment of power-on. This surge current is usually more than 100 times larger than when the switching power supply is working normally, which has a greater impact on the mains power grid and the air switch at the source, and may even cause the air switch to trip or fail to close. The characteristics of this circuit are: when it is just turned on, the charging circuit composed of the first resistor R1, the second resistor R2, and the third resistor R3 charges the first electrolytic capacitor EC1. Since the voltage across the first electrolytic capacitor EC1 cannot change suddenly, the voltage across the first electrolytic capacitor EC1 slowly rises to the conduction voltage of the first MOS tube Q1. Before this, the first MOS tube Q1 connected in series with the second electrolytic capacitor EC2 is turned off because the gate voltage does not reach the conduction threshold voltage. At this time, the current charges the fourth electrolytic capacitor EC2 through the fourth resistor R4. Due to the existence of the current-limiting fourth resistor R4, the charging current is limited to a controllable range, which plays a role in suppressing surge current. When the RC charging loop composed of the first resistor R1, the second resistor R2, the third resistor R3, and the first electrolytic capacitor EC1 is also charged to the threshold conduction voltage of the first MOS tube Q1, the first MOS tube Q1 is turned on. Because the conduction resistance of the first MOS tube is very small, much smaller than the current-limiting fourth resistor R4, the fourth resistor R4 is bypassed, and the input current charges the second electrolytic capacitor EC2 through the first MOS tube Q1, and the second electrolytic capacitor EC2 then discharges to the load through the body diode of the first MOS tube Q1.

[0065] In summary, the utility model has the following beneficial effects:

[0066] 1. When the circuit is just powered on, due to the existence of the fourth current-limiting resistor R4, the charging current of the second electrolytic capacitor EC2 is suppressed within a controllable range, and after the second electrolytic capacitor EC2 is fully charged, the loop current gradually decreases to a normal value. At this time, the first MOS tube Q1 is turned on to bypass the current-limiting resistor. Since the on-resistance of the first MOS tube Q1 is very small, at the milliohm level, much smaller than the fourth current-limiting resistor R4 (about 5-20 ohms), the loop current almost entirely flows through the first MOS tube Q1. Since the on-resistance of the MOS tube Q1 is very small, the loss P=I2×R on the first MOS tube Q1 is also very small, which improves the power supply efficiency.

[0067] 2. When the circuit switches continuously in a short period of time, the voltage on the first electrolytic capacitor EC1 is consumed by the third resistor R3, and the first MOS tube Q1 is turned off. At this time, the switch is turned on, and the surge current is limited by the fourth resistor R4, so that the surge current suppression circuit is always effective.

[0068] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A flyback switching power supply surge current suppression device, characterized in that: include: Bridge rectifier circuit, surge current suppression circuit, filter circuit, startup circuit, IC power supply circuit, main power conversion circuit, peak absorption circuit, voltage stabilization feedback circuit, output rectifier filter circuit; The input end of the bridge rectifier circuit is connected to the mains, and the surge current suppression circuit is connected to the output end of the bridge rectifier circuit and the filter circuit; The startup circuit is respectively connected to the surge current suppression circuit and the main power conversion circuit; The IC power supply circuit is connected to the main power conversion circuit; The main power conversion circuit is connected to the peak absorption circuit and the IC power supply circuit; The voltage stabilizing feedback circuit is connected to the main power conversion circuit and the output rectifying and filtering circuit.

2. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The bridge rectifier circuit comprises: a first diode, a second diode, a third diode and a fourth diode; The anode of the first diode is connected to the positive pole of the mains, the cathode of the first diode is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the fourth diode, and the anode of the second diode is connected to the negative pole of the mains; A cathode of the third diode is connected to an anode of the first diode, and an anode of the third diode is connected to an anode of the fourth diode.

3. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The surge current suppression circuit comprises: a first resistor, a second resistor, a third resistor, a fourth resistor, a first MOS tube, and a first electrolytic capacitor; The positive electrode of the bridge rectifier circuit is connected to the negative electrode of the bridge rectifier circuit through the first resistor, the second resistor, and the first electrolytic capacitor; The third resistor is connected in parallel with the first electrolytic capacitor; The positive electrode of the bridge rectifier circuit is connected to the negative electrode of the bridge rectifier circuit through the filter circuit and the first MOS tube; The gate of the first MOS tube is connected to the negative electrode of the bridge rectifier circuit through the first electrolytic capacitor; Two ends of the fourth resistor are respectively connected to the drain and source of the first MOS tube.

4. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The startup circuit comprises: a fifth resistor and a sixth resistor; The inrush current suppression circuit is connected to the main power conversion circuit via the fifth resistor and the sixth resistor.

5. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The peak absorption circuit includes: a fifth diode, a seventh resistor, and a first capacitor; The inrush current suppression circuit is connected to the main power conversion circuit via the first capacitor and the reverse-conducting fifth diode; the seventh resistor is connected in parallel with the fifth diode.

6. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The IC power supply circuit comprises: an eighth resistor, a sixth diode and a third electrolytic capacitor; The main power conversion circuit is grounded through the eighth resistor, the sixth diode, and the third electrolytic capacitor.

7. The flyback switching power supply surge current suppression device according to claim 1, characterized in that: The main power conversion circuit includes: a main conversion circuit control chip, a ninth resistor, a tenth resistor, a second MOS tube, a transformer, and an eleventh resistor; The main conversion circuit control chip is grounded through the ninth resistor; The main conversion circuit control chip is grounded through the tenth resistor and the eleventh resistor; The main conversion circuit control chip is connected to the drain of the second MOS tube through the tenth resistor; The main conversion circuit control chip is connected to the gate of the second MOS tube; The source of the second MOS tube is connected to the peak absorption circuit; One end of the first winding of the transformer is connected to the positive electrode of the bridge rectifier circuit, and the other end is connected to the source electrode of the second MOS tube; One end of the second winding of the transformer is connected to the IC power supply circuit, and the other end is grounded; The third winding of the transformer is connected to the output rectification and filtering circuit.

8. The surge current suppression device according to claim 1, characterized in that: The voltage stabilizing feedback circuit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a three-terminal voltage regulator, and an optical coupler; The first end of the optical coupler is grounded, the second end is connected to the main power conversion circuit, and the second end, the third end, and the fourth end are connected to the fourteenth resistor; The third end of the optical coupler is connected to the output rectification and filtering circuit through the thirteenth resistor; The fourth end of the optical coupler is connected to the output rectification and filtering circuit through the second capacitor and the fifteenth resistor; The third capacitor, the sixteenth resistor and the second capacitor are connected in parallel; The fourth terminal of the optical coupler is connected to the output rectifier and filter circuit through the three-terminal voltage regulator and the fifteenth resistor; The fourth terminal of the optical coupler is connected to the output rectifier and filter circuit through the three-terminal voltage regulator tube and the fourth capacitor; The fourth terminal of the optical coupler is connected to the output rectification and filtering circuit through the three-terminal voltage regulator and the twelfth resistor.

9. The surge current suppression device according to claim 1, characterized in that: The output rectification and filtering circuit comprises: a seventh diode and a fourth electrolytic capacitor; The anode of the seventh diode is connected to the main power conversion circuit, and the cathode is connected to the voltage stabilization feedback circuit through the fourth electrolytic capacitor; Both ends of the fourth electrolytic capacitor serve as outputs.

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