Surge suppression circuit, surge suppression system and switching power supply

Abstract

The utility model discloses a surge suppression circuit, a surge suppression system and a switching power supply. The surge suppression circuit comprises a resistance circuit, a rectification circuit and a switching circuit. The input end of the rectifying circuit is connected with the power input end, and the output end of the rectifying circuit is connected with the power output end; the first end of the resistance circuit is connected with the output end of the rectifying circuit, and the second end of the resistance circuit is connected with the power output end and used for suppressing surge current; and the switching circuit is connected with the power supply input end and the second end of the resistance circuit and is used for being in an off state within the surge suppression time, so that the resistance circuit is used for suppressing surge current, the switching circuit is in an on state within the non-surge suppression time, the resistance circuit is bypassed, the circuit loss is reduced, and the charging efficiency of the switching power supply is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of switch circuits, and in particular to a surge suppression circuit, a surge suppression system and a switch power supply. Background Art

[0002] A switching power supply is a highly efficient, high-frequency power conversion device that converts input voltage to output voltage by controlling the on and off of switching devices.

[0003] Existing switching power supplies usually include a large capacitor as a filter capacitor. Before the switching power supply is connected to the public power grid, the voltage at the input end of the switching power supply is zero. When the switching power supply is connected to the public power grid, the public power grid will charge the filter capacitor and generate a large surge current, posing a safety hazard to the switching power supply.

[0004] In order to solve the above problems, an NTC (Negative Temperature Coefficient, NTC for short) resistor is set at the input end of the existing switching power supply. When the switching power supply is connected to the public power grid, the temperature of the NTC resistor is low, so the NTC resistance value is relatively large, and it has good suppression ability for surge current. However, after the switching power supply has been working for a period of time, the temperature of the NTC resistor rises and the resistance value of the NTC resistor begins to decrease. At this time, if the plug of the switching power supply is replugged in the case of a hot machine, the surge current will also be relatively large, and the suppression effect will be worse. At the same time, the NTC resistor is in the circuit loop of the switching power supply in series, and it will cause loss when the switching power supply is working normally, affecting the efficiency of the switching power supply. Utility Model Content

[0005] The embodiments of the utility model provide a surge suppression circuit, a surge suppression system and a switching power supply to solve the problem that the existing switching power supply has a poor surge suppression effect and affects the charging efficiency.

[0006] A surge suppression circuit comprises a resistance circuit, a rectification circuit and a switch circuit;

[0007] The input end of the rectifier circuit is connected to the input end of the power supply, and the output end of the rectifier circuit is connected to the output end of the power supply;

[0008] The first end of the resistance circuit is connected to the output end of the rectifier circuit, and the second end of the resistance circuit is connected to the output end of the power supply, for suppressing surge current;

[0009] The switch circuit is connected to the power input terminal and the second end of the resistance circuit, and is used to be in an off state during the surge suppression time and in an on state during the non-surge suppression time.

[0010] Furthermore, the first input end of the rectifier circuit is connected to the phase line of the power supply input end, the second input end of the rectifier circuit is connected to the neutral line of the power supply input end, the first output end of the rectifier circuit is connected to the positive pole of the power supply output end, and the second output end of the rectifier circuit is connected to the negative pole of the power supply output end.

[0011] Further, the rectifier circuit includes a first diode, a second diode, a third diode and a fourth diode;

[0012] The anode of the first diode and the cathode of the second diode are connected in common and connected to the first input terminal of the rectifier circuit;

[0013] The cathode of the third diode is connected to the anode of the fourth diode and is connected to the second input terminal of the rectifier circuit;

[0014] The cathode of the first diode is connected to the cathode of the fourth diode in common and is connected to the first output terminal of the rectifier circuit;

[0015] The anode of the second diode is connected to the anode of the third diode and is connected to the second output end of the rectifier circuit.

[0016] Further, the first end of the resistance circuit is connected to the first output end of the rectifier circuit, and the second end of the resistance circuit is connected to the positive electrode of the power supply output end;

[0017] Alternatively, the first end of the resistance circuit is connected to the second output end of the rectifier circuit, and the second end of the resistance circuit is connected to the negative electrode of the power supply output end.

[0018] Furthermore, the resistance circuit includes at least one NTC resistor.

[0019] Furthermore, the switch circuit includes at least two switch tubes, and the switch tubes are insulated gate bipolar transistors or thyristors.

[0020] Furthermore, the switch circuit includes a first switch tube and a second switch tube;

[0021] The first end of the first switch tube is connected to the phase line of the power input end, the second end of the first switch tube is connected to the second end of the resistance circuit, and the third end of the first switch tube is the first control end;

[0022] The first end of the second switch tube is connected to the neutral line of the power input end, the second end of the second switch tube is connected to the second end of the resistance circuit, and the third end of the second switch tube is the second control end.

[0023] Furthermore, the switch circuit further includes a third switch tube and a fourth switch tube;

[0024] The first end of the third switch tube is connected to the phase line of the power input end, the second end of the third switch tube is connected to the power output end, and the third end of the third switch tube is a third control end;

[0025] The first end of the fourth switch tube is connected to the neutral line of the power input end, the second end of the fourth switch tube is connected to the power output end, and the third end of the fourth switch tube is a fourth control end.

[0026] A surge suppression system comprises a control module and the above-mentioned surge suppression circuit;

[0027] The control module is connected to the switch circuit and is used to switch the switch circuit into an off state or an on state.

[0028] A switching power supply comprises the above-mentioned surge suppression system.

[0029] The above-mentioned surge suppression circuit, surge suppression system and switching power supply, the surge suppression circuit includes a resistor circuit, a rectifier circuit and a switch circuit; the input end of the rectifier circuit is connected to the power input end, and the output end of the rectifier circuit is connected to the power output end; the first end of the resistor circuit is connected to the output end of the rectifier circuit, and the second end of the resistor circuit is connected to the power output end, which is used to suppress surge current; the switch circuit is connected to the power input end and the second end of the resistor circuit, and is used to be in an off state during the surge suppression time, thereby using the resistor circuit to suppress the surge current, and is in an on state during the non-surge suppression time, thereby bypassing the resistor circuit, reducing circuit losses, and improving the charging efficiency of the switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a circuit diagram of a surge suppression circuit in one embodiment of the utility model;

[0032] Figure 2 It is another circuit diagram of a surge suppression circuit in one embodiment of the utility model;

[0033] Figure 3 It is another circuit diagram of a surge suppression circuit in one embodiment of the utility model;

[0034] Figure 4 It is another circuit diagram of a surge suppression circuit in one embodiment of the utility model;

[0035] Figure 5 It is a circuit diagram of a surge suppression system in one embodiment of the utility model.

[0036] In the figure: 1. surge suppression circuit; 11. resistance circuit; 12. rectification circuit; 13. switch circuit; 2. control module. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] It should be understood that the utility model can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and fully convey the scope of the utility model to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0039] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. On the contrary, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0040] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0041] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be a limitation of the present invention. When used herein, the singular forms "a", "an" and " / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0042] In order to thoroughly understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0043] This embodiment provides a surge suppression circuit 1, such as Figure 1 As shown, it includes a resistor circuit 11, a rectifier circuit 12 and a switch circuit 13; the input end of the rectifier circuit 12 is connected to the power input end, and the output end of the rectifier circuit 12 is connected to the power output end; the first end of the resistor circuit 11 is connected to the output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the power output end, which is used to suppress surge current; the switch circuit 13 is connected to the power input end and the second end of the resistor circuit 11, and is used to be in an off state during the surge suppression time and in a on state during the non-surge suppression time.

[0044] The surge suppression time refers to the time set by the user. The surge suppression time is calculated from the moment the switching power supply is connected to the public power grid AC. The surge suppression time is greater than the charging time of the filter capacitor C1.

[0045] As an example, the surge suppression circuit 1 is applied in a switching power supply. The surge suppression circuit 1 includes a rectifier circuit 12. The input end of the rectifier circuit 12 is connected to the power input end, and the output end of the rectifier circuit 12 is connected to the power output end, for converting an AC signal into a DC signal. Exemplarily, the power input end is used to connect to a public power grid AC. The power output end is used to connect to a load. Optionally, the rectifier circuit 12 can be a full-bridge rectifier circuit 12 or a half-bridge rectifier circuit 12.

[0046] Optionally, the switching power supply further includes a voltage conversion circuit, which is arranged between the rectifier circuit 12 and the power output terminal, and is used to convert a DC signal into a DC voltage signal adapted to the load. The DC signal can be a DC voltage or a DC current. Exemplarily, the voltage conversion circuit is a DCDC voltage conversion circuit.

[0047] As an example, Figure 2 As shown, the switching power supply further includes a filter capacitor C1, which is arranged on the power output terminal (Out+, Out-) for filtering the AC signal at the power output terminal.

[0048] As an example, the first end of the resistor circuit 11 is connected to the output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the power supply output end, which is used to suppress the surge current, thereby preventing the switching power supply from being damaged by the surge current at the moment of connecting to the public power grid AC. It can be understood that at the moment when the switching power supply is connected to the public power grid AC, the rectifier circuit 12 will charge the filter, thereby generating a large surge current. The first end of the resistor circuit 11 is connected to the output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the power supply output end, so that the resistor circuit 11 can be used to suppress the surge current.

[0049] As an example, the switch circuit 13 is connected to the power input terminal and the second end of the resistor circuit 11, and is used to be in a disconnected state during the surge suppression time and in a conductive state during the non-surge suppression time. For example, the switching power supply also includes a control module 2. When the control module 2 detects that the switching power supply is connected to the public power grid AC, the timing starts. During the surge suppression time, the switch circuit 13 is controlled to be in a disconnected state, so that the resistor circuit 11 suppresses the surge current. During the non-surge suppression time, the filter capacitor C1 is charged. At this time, there is no surge current in the surge suppression circuit 1. The control module 2 controls the switch circuit 13 to be in a conductive state, so that the resistor circuit 11 is bypassed through the switch circuit 13, thereby reducing the loss of the resistor circuit 11. In addition, when the resistor circuit 11 adopts an NTC resistor, the bypassed resistor circuit 11 can maintain a lower temperature, so that when the switching power supply is hot-plugged, it can ensure that the resistor circuit 11 can present a larger resistance value, so that when the switching power supply is hot-plugged, the surge current can be effectively suppressed.

[0050] In this embodiment, the surge suppression circuit 1 includes a resistor circuit 11, a rectifier circuit 12 and a switch circuit 13; the input end of the rectifier circuit 12 is connected to the power input end, and the output end of the rectifier circuit 12 is connected to the power output end; the first end of the resistor circuit 11 is connected to the output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the power output end, which is used to suppress surge current; the switch circuit 13 is connected to the power input end and the second end of the resistor circuit 11, and is used to be in an off state during the surge suppression time, thereby using the resistor circuit 11 to suppress the surge current, and is in an on state during the non-surge suppression time, thereby bypassing the resistor circuit 11, reducing circuit losses, and improving the charging efficiency of the switching power supply.

[0051] In one embodiment, if Figure 2 As shown, the first input terminal of the rectifier circuit 12 is connected to the phase line L of the power input terminal, the second input terminal of the rectifier circuit 12 is connected to the neutral line N of the power input terminal, the first output terminal of the rectifier circuit 12 is connected to the positive pole Out+ of the power output terminal, and the second output terminal of the rectifier circuit 12 is connected to the negative pole Out- of the power output terminal.

[0052] In this embodiment, the first input terminal of the rectifier circuit 12 is connected to the phase line L of the power input terminal, the second input terminal of the rectifier circuit 12 is connected to the neutral line N of the power input terminal, the first output terminal of the rectifier circuit 12 is connected to the positive pole Out+ of the power output terminal, and the second output terminal of the rectifier circuit 12 is connected to the negative pole Out- of the power output terminal, so that the positive cycle AC signal and the negative cycle AC signal are both rectified into DC signals, forming a full-bridge rectifier circuit 12 to provide a more stable DC signal.

[0053] In one embodiment, if Figure 2 As shown, the rectifier circuit 12 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 in common with the cathode of the second diode D2, and is connected to the first input terminal of the rectifier circuit 12; the cathode of the third diode D3 is connected in common with the anode of the fourth diode D4, and is connected to the second input terminal of the rectifier circuit 12; the cathode of the first diode D1 is connected in common with the cathode of the fourth diode D4, and is connected to the first output terminal of the rectifier circuit 12; the anode of the second diode D2 is connected in common with the anode of the third diode D3, and is connected to the second output terminal of the rectifier circuit 12.

[0054] Exemplarily, the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 are silicon diodes, which have the characteristics of low conduction voltage drop, high reverse withstand voltage and fast response speed, thereby providing good rectification characteristics and high withstand voltage capability.

[0055] In this embodiment, by connecting the anode of the first diode D1 and the cathode of the second diode D2 together, and connecting them to the first input terminal of the rectifier circuit 12; connecting the cathode of the third diode D3 and the anode of the fourth diode D4 together, and connecting them to the second input terminal of the rectifier circuit 12; connecting the cathode of the first diode D1 and the cathode of the fourth diode D4 together, and connecting them to the first output terminal of the rectifier circuit 12; connecting the anode of the second diode D2 and the anode of the third diode D3 together, and connecting them to the second output terminal of the rectifier circuit 12, full-bridge rectification can be achieved.

[0056] In one embodiment, if Figure 2 or Figure 4 As shown, the first end of the resistor circuit 11 is connected to the first output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the positive electrode Out+ of the power output end; or, the first end of the resistor circuit 11 is connected to the second output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the negative electrode Out- of the power output end.

[0057] In this embodiment, the first end of the resistor circuit 11 is connected to the first output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the positive electrode Out+ of the power supply output end, or the first end of the resistor circuit 11 is connected to the second output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the negative electrode Out- of the power supply output end, both of which can suppress surge current, thereby making the circuit design more flexible.

[0058] In one embodiment, if Figure 2As shown, the resistance circuit 11 includes at least one NTC resistor. In the present embodiment, when the resistance circuit 11 includes one NTC resistor, the NTC resistor is directly connected in series between the first end and the second end of the resistance circuit 11. When the resistance circuit 11 includes at least two NTC resistors, the at least two NTC resistors can be arranged in series or in parallel between the first end and the second end of the resistance circuit 11. The specific selection can be made based on actual experience and is not limited here. In the present embodiment, the use of an NTC resistor in the resistance circuit 11 can reduce the resistance value of the resistance circuit 11 when the temperature of the NTC resistor rises, thereby reducing circuit losses.

[0059] In one embodiment, if Figure 2-4 As shown, the switch circuit 13 includes at least two switch tubes, which are insulated gate bipolar transistors or thyristors. In this embodiment, since there is no body diode in the insulated gate bipolar transistors and thyristors, when there is a large surge current in the surge suppression circuit 1, there will be no situation where the surge current breaks through the body diode and damages the switch circuit 13, thereby improving the reliability of the switch circuit 13.

[0060] In one embodiment, if Figure 2 As shown, the switch circuit 13 includes a first switch tube Q1 and a second switch tube Q2; the first end of the first switch tube Q1 is connected to the phase line L of the power input end, the second end of the first switch tube Q1 is connected to the second end of the resistance circuit 11, and the third end of the first switch tube Q1 is the first control end; the first end of the second switch tube Q2 is connected to the neutral line N of the power input end, the second end of the second switch tube Q2 is connected to the second end of the resistance circuit 11, and the third end of the second switch tube Q2 is the second control end.

[0061] The first switch tube Q1 and the second switch tube Q2 are insulated gate bipolar transistors or thyristors.

[0062] As an example, the collector or anode of the first switch tube Q1 is connected to the phase line L of the power input terminal, the emitter or cathode of the first switch tube Q1 is an insulated gate bipolar transistor or a thyristor, and the third end of the first switch tube Q1 is a gate. The collector or anode of the second switch tube Q2 is connected to the neutral line N of the power input terminal, the emitter or cathode of the second switch tube Q2 is connected to the second end of the resistor circuit 11, and the third end of the second switch tube Q2 is a gate.

[0063] As an example, the first switch tube Q1 is connected in parallel with the first diode D1 and the resistor circuit 11 in the rectifier circuit 12, and the second switch tube Q2 is connected in parallel with the third diode D3 and the resistor circuit 11 in the rectifier circuit 12. The control module 2 detects the zero-crossing point of the AC signal, and according to the zero-crossing point of the AC signal, the first switch tube Q1 and the second switch tube Q2 are alternately turned on, thereby bypassing the resistor circuit 11 while ensuring the normal rectification function, so as to avoid the resistor circuit 11 causing additional circuit loss. It should be noted that the control module 2 detects the zero-crossing point of the AC signal, and according to the zero-crossing point of the AC signal, the first switch tube Q1 and the second switch tube Q2 are alternately turned on, which can adopt the technology known to those skilled in the art, and will not be repeated here. For example, the first switch tube Q1 is turned on in the positive cycle of the AC signal, and the second switch tube Q2 is turned on in the negative cycle of the AC signal, so as to ensure the normal rectification function while bypassing the resistor circuit 11.

[0064] In this embodiment, the first end of the first switch tube Q1 is connected to the phase line L of the power input end, the second end of the first switch tube Q1 is connected to the second end of the resistance circuit 11, and the third end of the first switch tube Q1 is the first control end; the first end of the second switch tube Q2 is connected to the neutral line N of the power input end, the second end of the second switch tube Q2 is connected to the second end of the resistance circuit 11, and the third end of the second switch tube Q2 is the second control end, so that while ensuring the normal rectification function, the resistance circuit 11 is bypassed to avoid additional circuit loss caused by the resistance circuit 11.

[0065] In one embodiment, the switch circuit 13 further includes a third switch tube Q3 and a fourth switch tube Q4; a first end of the third switch tube Q3 is connected to the phase line L of the power input end, a second end of the third switch tube Q3 is connected to the power output end, and a third end of the third switch tube Q3 is a third control end; a first end of the fourth switch tube Q4 is connected to the neutral line N of the power input end, a second end of the fourth switch tube Q4 is connected to the power output end, and a third end of the fourth switch tube Q4 is a fourth control end.

[0066] The first switch tube Q1 and the second switch tube Q2 are insulated gate bipolar transistors or thyristors.

[0067] As an example, the collector or anode of the third switch tube Q3 is connected to the phase line L of the power input end, the emitter or cathode of the third switch tube Q3 is connected to the power output end, and the third end of the third switch tube Q3 is the gate; the collector or anode of the fourth switch tube Q4 is connected to the neutral line N of the power input end, the emitter or cathode of the fourth switch tube Q4 is connected to the power output end, and the third end of the fourth switch tube Q4 is the gate.

[0068] Specifically, the third switch tube Q3 is connected in parallel with the second diode D2 in the rectifier circuit 12, and the fourth switch tube Q4 is connected in parallel with the fourth diode D4 in the rectifier circuit 12. In this example, by connecting the third switch tube Q3 in parallel with the second diode D2, when the second diode D2 transmits an electrical signal, the third switch tube Q3 can be controlled to be turned on, so that the electrical signal is transmitted through the third switch tube Q3, thereby reducing the loss of the second diode D2, and the fourth switch tube Q4 is connected in parallel with the fourth diode D4, when the fourth diode D4 transmits an electrical signal, the fourth switch tube Q4 can be controlled to be turned on, so that the electrical signal is transmitted through the fourth switch tube Q4, thereby reducing the loss of the fourth diode D4. Exemplarily, the working states of the second diode D2 and the fourth diode D4 can be detected by the control module 2, and when the second diode D2 transmits an electrical signal, the third switch tube Q3 is controlled to be turned on, and when the second diode D2 does not transmit an electrical signal, the third switch tube Q3 is controlled to be turned off. Similarly, when the fourth diode D4 transmits an electrical signal, the fourth switch tube Q4 is controlled to be turned on, and when the fourth diode D4 does not transmit an electrical signal, the fourth switch tube Q4 is controlled to be turned off.

[0069] In this embodiment, the switch circuit 13 also includes a third switch tube Q3 and a fourth switch tube Q4; the first end of the third switch tube Q3 is connected to the phase line L of the power input end, the second end of the third switch tube Q3 is connected to the power output end, and the third end of the third switch tube Q3 is the third control end; the first end of the fourth switch tube Q4 is connected to the neutral line N of the power input end, the second end of the fourth switch tube Q4 is connected to the power output end, and the third end of the fourth switch tube Q4 is the fourth control end, thereby further reducing the loss of the rectifier circuit 12.

[0070] This embodiment provides a surge suppression system, including a control module 2 and the above-mentioned surge suppression circuit 1; the control module 2 is connected to the switch circuit 13 and is used to switch the switch circuit 13 into an off state or an on state. Figure 3 or Figure 4 As shown, the control module 3 outputs a VG1 signal to control the first switch tube Q1, the control module 3 outputs a VG2 signal to control the second switch tube Q2, the control module 3 outputs a VG3 signal to control the third switch tube Q3, and the control module 3 outputs a VG4 signal to control the fourth switch tube Q4.

[0071] In this embodiment, the control module 2 is connected to the switch circuit 13 to switch the switch circuit 13 into an off state or an on state, so that it can be in an off state during the surge suppression time, thereby using the resistor circuit 11 to suppress the surge current, and in an on state during the non-surge suppression time, thereby bypassing the resistor circuit 11, reducing circuit losses, and improving the charging efficiency of the switching power supply. It should be noted that the relevant control logic executed by the control module 2 can adopt the control logic known to those skilled in the art, as long as the input end of the rectifier circuit 12 is connected to the power input end, and the output end of the rectifier circuit 12 is connected to the power output end; the first end of the resistor circuit 11 is connected to the output end of the rectifier circuit 12, and the second end of the resistor circuit 11 is connected to the power output end, for suppressing the surge current; the switch circuit 13 is connected to the power input end and the second end of the resistor circuit 11. And the control module 2 controls the switch circuit 13 to be turned on during the surge suppression time, and controls the switch circuit 13 to be disconnected during the non-surge suppression time, bypassing the resistor circuit 11.

[0072] This embodiment provides a switching power supply, including the above-mentioned surge suppression system.

[0073] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A surge suppression circuit, characterized in that: It includes a resistance circuit, a rectification circuit and a switching circuit; The input end of the rectifier circuit is connected to the input end of the power supply, and the output end of the rectifier circuit is connected to the output end of the power supply; The first end of the resistance circuit is connected to the output end of the rectifier circuit, and the second end of the resistance circuit is connected to the output end of the power supply, for suppressing surge current; The switch circuit is connected to the power input terminal and the second end of the resistance circuit, and is used to be in an off state during the surge suppression time and in an on state during the non-surge suppression time.

2. The surge suppression circuit according to claim 1, characterized in that: The first input end of the rectifier circuit is connected to the phase line of the power input end, the second input end of the rectifier circuit is connected to the neutral line of the power input end, the first output end of the rectifier circuit is connected to the positive pole of the power output end, and the second output end of the rectifier circuit is connected to the negative pole of the power output end.

3. The surge suppression circuit according to claim 2, characterized in that: The rectifier circuit includes a first diode, a second diode, a third diode and a fourth diode; The anode of the first diode and the cathode of the second diode are connected in common and connected to the first input terminal of the rectifier circuit; The cathode of the third diode is connected to the anode of the fourth diode and is connected to the second input terminal of the rectifier circuit; The cathode of the first diode is connected to the cathode of the fourth diode in common and is connected to the first output terminal of the rectifier circuit; The anode of the second diode is connected to the anode of the third diode and is connected to the second output end of the rectifier circuit.

4. The surge suppression circuit according to claim 2, wherein: The first end of the resistance circuit is connected to the first output end of the rectifier circuit, and the second end of the resistance circuit is connected to the positive electrode of the power supply output end; Alternatively, the first end of the resistance circuit is connected to the second output end of the rectifier circuit, and the second end of the resistance circuit is connected to the negative electrode of the power supply output end.

5. The surge suppression circuit according to claim 1, wherein: The resistance circuit includes at least one NTC resistor.

6. The surge suppression circuit according to claim 1, wherein: The switch circuit includes at least two switch tubes, and the switch tubes are insulated gate bipolar transistors or thyristors.

7. The surge suppression circuit according to claim 6, characterized in that: The switch circuit includes a first switch tube and a second switch tube; The first end of the first switch tube is connected to the phase line of the power input end, the second end of the first switch tube is connected to the second end of the resistance circuit, and the third end of the first switch tube is the first control end; The first end of the second switch tube is connected to the neutral line of the power input end, the second end of the second switch tube is connected to the second end of the resistance circuit, and the third end of the second switch tube is the second control end.

8. The surge suppression circuit according to claim 7, characterized in that: The switch circuit also includes a third switch tube and a fourth switch tube; The first end of the third switch tube is connected to the phase line of the power input end, the second end of the third switch tube is connected to the power output end, and the third end of the third switch tube is a third control end; The first end of the fourth switch tube is connected to the neutral line of the power input end, the second end of the fourth switch tube is connected to the power output end, and the third end of the fourth switch tube is a fourth control end.

9. A surge suppression system, characterized in that: comprising a control module and a surge suppression circuit as claimed in any one of claims 1 to 8; The control module is connected to the switch circuit and is used to switch the switch circuit into an off state or an on state.

10. A switching power supply, characterized in that: Comprising a surge suppression system as claimed in claim 9.

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