Anti-short-circuit protection circuit and electronic equipment

Abstract

The utility model relates to an anti-short-circuit protection circuit and electronic equipment. The anti-short-circuit protection circuit comprises a protection circuit and a detection circuit which are connected between an input power supply and a power supply chip, the protection circuit is connected in parallel to two ends of an input power supply and used for short-circuit protection when the input power supply is abnormal. The protection circuit comprises a first fuse and a protection circuit which are connected in series; the detection circuit comprises a power supply input detection circuit and a current sampling circuit and is used for cutting off the circuit through the power supply control switch when abnormal feedback is performed; the power input detection circuit is connected in parallel to two ends of an input power and used for detecting the input power; and the current sampling circuit is connected in parallel to two ends of the protection circuit and used for detecting a steady-state current signal generated after the protection circuit is short-circuited. According to the invention, short-circuit protection can be carried out through the protection circuit when the steady-state abnormal input power supply is connected, and the circuit is cut off through the power supply control switch when abnormity is fed back through the detection circuit, so that circuit protection when the steady-state abnormal input power supply is connected is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to a short-circuit protection circuit and electronic equipment. BACKGROUND

[0002] The surge protection of electronic equipment has become a problem that electronic product designers must face and solve. When the power transmission line is struck by lightning or induced lightning, the induced surge current in the transmission line will generate a surge current. At present, the surge protection designed for different ports can protect against such transient high-voltage surges. However, in addition to the above transient high-voltage surge problem, some power misconnection problems often occur in the field, for example, for a device with a DC 12V power input, due to the operation error of the field personnel, AC 220V input is mistakenly used. This abnormal steady-state input power may cause the protection device to short circuit, causing functional problems of the device, causing abnormal power supply of the device, and even causing fire accidents and other safety accidents.

[0003] In view of the problem that the related art lacks a protection circuit for abnormal steady-state input power, no effective solution has been proposed so far. CONTENT OF THE INVENTION

[0004] Therefore, it is necessary to provide a short-circuit protection circuit and electronic equipment capable of protecting against abnormal steady-state input power.

[0005] In a first aspect, a short-circuit protection circuit is provided in the present embodiment, comprising: a protection circuit and a detection circuit connected between an input power and a power supply chip;

[0006] The protection circuit is connected in parallel across the input power, for short-circuit protection when the input power is abnormal; the protection circuit comprises a first fuse and a protection circuit connected in series;

[0007] The detection circuit comprises a power input detection circuit and a current sampling circuit, for cutting off the circuit through a power control switch when feedback is abnormal;

[0008] The power input detection circuit is connected in parallel across the input power, for detecting the input power;

[0009] The current sampling circuit is connected in parallel across the protection circuit, for detecting a steady-state current signal generated after the protection circuit is short-circuited.

[0010] In some embodiments, the protection circuit further comprises a plurality of capacitors connected in parallel.

[0011] In some embodiments, the protection circuit includes a clamping protection device, the action voltage of the clamping protection device is higher than the voltage of the input power supply, and the clamping voltage of the clamping protection device is lower than the protection voltage of the power supply chip.

[0012] In some embodiments, a second fuse is further included and connected in series with the input power supply.

[0013] When the protection circuit is short-circuited, the first fuse and the second fuse are triggered to protect the circuit, and the steady-state current signal detection is triggered.

[0014] In some embodiments, the detection circuit further includes a relay switch.

[0015] When the protection circuit is short-circuited, the relay switch is triggered to be closed.

[0016] The detection circuit is further configured to cut off the circuit through the power supply control switch according to the electrical signal generated by the closing of the relay switch.

[0017] In some embodiments, a filter circuit is further included and connected in parallel between the current sampling circuit and the power supply chip.

[0018] The filter circuit includes a differential mode filter circuit and a common mode filter circuit, and is configured to filter and protect the subsequent circuit.

[0019] In some embodiments, the filter circuit includes a resistor, a common mode inductor, a differential mode inductor, and a plurality of capacitors, the capacitors are connected to the input side of the common mode inductor, and the resistor, the differential mode inductor, and the capacitors are connected to the output side of the common mode inductor.

[0020] In some embodiments, a processing platform is further included and connected to the detection circuit.

[0021] The processing platform is configured to control the power supply control switch to cut off the circuit and trigger an alarm according to the abnormal signal fed back by the power supply input detection circuit and the current sampling circuit.

[0022] In a second aspect, an electronic device including the short-circuit protection circuit of the first aspect is provided.

[0023] Compared with the related art, the short circuit protection circuit and the electronic device provided in the embodiment, wherein the circuit comprises: a protection circuit and a detection circuit connected between an input power supply and a power supply chip; the protection circuit is connected in parallel across the input power supply, and is used for short circuit protection when the input power supply is abnormal; the protection circuit comprises a first fuse and a protection circuit connected in series; the detection circuit comprises a power supply input detection circuit and a current sampling circuit, and is used for cutting off the circuit through a power supply control switch when feedback is abnormal; the power supply input detection circuit is connected in parallel across the input power supply, and is used for detecting the input power supply; and the current sampling circuit is connected in parallel across the protection circuit, and is used for detecting a steady-state current signal generated after the protection circuit is short-circuited. Through the embodiment, short circuit protection can be performed through the protection circuit when an abnormal input power supply in a steady state is accessed, and the input power supply and the steady-state current signal are detected through the detection circuit, so that the circuit is cut off through the power supply control switch when feedback is abnormal, thereby realizing short circuit protection of the circuit when the abnormal input power supply in the steady state is accessed.

[0024] The details of one or more embodiments of the present application are presented in the following drawings and description to make other features, objects and advantages of the present application more apparent. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the present application and illustrate the illustrative embodiments of the present application and their description serves to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0026] Figure 1 FIG. 1 is a schematic diagram of a short circuit protection circuit in an embodiment;

[0027] Figure 2 FIG. 2 is a schematic diagram of a design framework of a short circuit protection circuit in an embodiment. DETAILED DESCRIPTION

[0028] In order to more clearly understand the purpose, technical scheme and advantages of the present application, the present application is described and explained below in combination with the drawings and embodiments.

[0029] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the same meaning as those commonly understood by a person having ordinary skill in the art to which the present application belongs. The terms "one", "a", "an", "the", "these", and similar terms in the present application do not mean "only one" or "exactly one", but can mean "one or more". The terms "include", "contain", "have", and any variant thereof in the present application are intended to cover the non-exclusive inclusion; for example, a process, method, and system, product or device containing a series of steps or modules (units) are not limited to the listed steps or modules (units), but can include steps or modules (units) not listed, or can include other steps or modules (units) inherent to the process, method, product or device. The terms "connect", "connected", "coupled" and the like in the present application do not mean physical or mechanical connection, but can include electrical connection, whether direct or indirect. The term "multiple" in the present application means two or more. The term "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. Generally, the character " / " means that the objects before and after are "or" relationship. The terms "first", "second", "third" and the like in the present application are only used to distinguish similar objects, and do not mean a specific order of the objects.

[0030] Surge protection of electronic devices has become a problem that electronic product designers must face and solve. When the power transmission line is struck by lightning or induced lightning, the induced surge current in the transmission line will generate a surge current. At present, surge protection designed for different ports can protect against such transient high voltage surges. However, in addition to the above transient high voltage surge problem, some power misconnection problems often occur in the field, for example, for a device with DC 12V power input, due to the operation error of field personnel, AC 220V input is mistakenly used. This abnormal steady-state input power may cause the protection device to short circuit, causing functional problems of the device, causing abnormal power supply of the device, and even causing fire accidents and other safety accidents.

[0031] In the embodiment, a short-circuit protection circuit is provided, Figure 1 is a schematic diagram of the short-circuit protection circuit in the embodiment, as Figure 1 shown, the short-circuit protection circuit comprises a protection circuit and a detection circuit connected between an input power supply and a power supply chip.

[0032] The protection circuit is connected in parallel between the input power supply and used for short circuit protection when the input power supply is abnormal; the protection circuit comprises a first fuse and a protection circuit connected in series; the detection circuit comprises a power input detection circuit and a current sampling circuit, used for cutting off the circuit through the power control switch when feedback is abnormal; the power input detection circuit is connected in parallel between the input power supply and used for detecting the input power supply; the current sampling circuit is connected in parallel between the protection circuit and used for detecting the steady-state current signal generated after the protection circuit is short-circuited.

[0033] The input power supply provides power for the entire circuit of the electronic device, and the power supply chip in the rear stage is responsible for converting the input power supply into voltage and current suitable for the circuit or device. As shown in Figure 1 The protection circuit and the detection circuit are connected in sequence between the input power supply V_in and the power supply chip U1, the protection circuit comprises a first fuse F1 and a protection circuit D1 connected in series, one end of the first fuse F1 is connected with the positive electrode of the input power supply V_in, the other end is connected with one end of the protection circuit D1, the other end of the protection circuit D1 is connected with the negative electrode of the input power supply V_in. The protection circuit can be a clamping type protection device selected for different input power supply ports, and the specific selection is related to the input power supply V_in and the power supply chip U1 in the rear stage.

[0034] The protection circuit is connected in parallel between the input power supply and can protect the protection device and the circuit in the rear stage by fusing the fuse when a transient high voltage surge such as lightning occurs; it can also protect the circuit by fusing the fuse and the protection device when an abnormal input power supply in a steady state is connected, for example, a 24V, 220V steady-state abnormal power supply is connected to the 18V port, the circuit may be maintained in a short circuit state before the fuse is fused, and the circuit is protected by the fuse and the protection device, even if the protection device fails in a short circuit state, the fuse connected in series with the protection device plays a role in short circuit protection, preventing the protection device and the circuit in the rear stage from being damaged due to short circuit.

[0035] The detection circuit includes a power input detection circuit and a current sampling circuit. The power input detection circuit is connected in parallel to the input power supply, and one end of the power input detection circuit V1 is connected to the positive pole of the input power supply V_in through a power control switch S1, and the other end is connected to the negative pole of the input power supply V_in, for real-time detection of the voltage of the input power supply, and when an abnormality is detected, the power control switch S1 is controlled to be turned off by the processing platform. The current sampling circuit I1 is connected in parallel to the protection circuit, one end of the current sampling circuit I1 is connected to the positive pole of the input power supply V_in through the power control switch S1, and the other end is connected to the negative pole of the input power supply V_in through a relay switch P1, for real-time detection of the current signal in the circuit, and when the protection circuit is short-circuited due to the connection of the abnormal input power supply with a stabilized voltage, there will be a continuous current path on the protection path, and the current sampling circuit can detect the steady-state current signal generated after the short circuit of the protection circuit, and when an abnormality is detected, the power control switch S1 is controlled to be turned off by the processing platform.

[0036] When the input power supply is normally connected to the short-circuit protection circuit, the short-circuit protection circuit is usually in a standby or monitoring state. At this time, the circuit will monitor the voltage, current and other parameters of the input power supply in real time to ensure that they fluctuate within a normal range. If these parameters remain stable and within the preset safety threshold, the short-circuit protection circuit will not take any action, allowing the circuit and device to work normally. When an abnormal input power supply is connected, including transient high voltage surges and steady-state input power supply abnormalities, when the protection circuit is short-circuited due to the connection of the abnormal input power supply with a stabilized voltage, the fuse connected in series with the protection device plays a role in short-circuit protection, preventing the protection device and the subsequent circuit from being damaged by short circuit, and there will be a continuous current path on the protection path, triggering the detection of the power input detection circuit and the current sampling circuit in the detection circuit, and feeding back the detected abnormality to the processing platform, and cutting off the circuit by the power control switch for protection.

[0037] Through the protection circuit and the detection circuit in the embodiment, the short-circuit protection can be effectively performed for transient high voltage surges and steady-state input power supply abnormalities, preventing the protection device and the subsequent circuit from being damaged by short circuit, and through the detection of the voltage and current in the circuit by the detection circuit, the circuit is protected by cutting off the circuit by the power control switch when an abnormality is fed back. Compared with the existing technology which can only perform surge protection for transient high voltage surges, the embodiment can also perform circuit protection for misconnected steady-state abnormal input power supply on the basis of surge protection.

[0038] In some embodiments, the protection circuit further includes a plurality of capacitors connected in parallel.

[0039] Specifically, as Figure 1As shown, the protection circuit includes a first fuse F1 and a protection circuit D1 connected in series, and capacitors C1 and C2 connected in parallel therein. The plurality of capacitors C1 and C2 connected in parallel serve to absorb high voltage of the power supply input to the ground plane after the fuse F1 in the protection circuit, prevent the final clamping voltage of the protection circuit from being too high after the fuse is increased, reduce the voltage difference of the input power supply to the ground plane, and prevent damage to the subsequent circuit when the circuit is protected.

[0040] It should be noted that, Figure 1 Only as an example, the embodiment does not limit the number of capacitors, etc.

[0041] By connecting a plurality of capacitors in parallel in the protection circuit in the embodiment, the high voltage of the power supply can be absorbed, and the problem of excessively high voltage caused by the series fuse in the protection circuit can be avoided.

[0042] In some embodiments, the protection circuit includes a clamping type protection device; the operating voltage of the clamping type protection device is higher than the voltage of the input power supply, and the clamping voltage of the clamping type protection device is lower than the protection voltage of the power supply chip.

[0043] Specifically, the protection circuit can be a clamping type protection device selected for different input power supply ports, and the specific selection is related to the input power supply V_in and the subsequent power supply chip U1. Since the switching type protection device has a freewheeling problem, the clamping type protection device is selected in the embodiment, and the operating voltage of the clamping type protection device needs to be higher than the voltage of the input power supply, and the specification of the subsequent power supply chip U1 is also considered to confirm the limited voltage range of the power supply chip U1 pin input, and the clamping voltage of the clamping type protection device also needs to be lower than the protection voltage of the power supply chip U1. In order to ensure the stability and reliability of the circuit, the operating voltage of the clamping type protection device is designed to be higher than the voltage of the input power supply while maintaining a margin of 10% to 20%.

[0044] By selecting the clamping type protection device to replace the switching type protection device as the protection circuit in the embodiment, the circuit protection can be effectively performed on the abnormal input power supply.

[0045] In some embodiments, a second fuse connected in series with the input power supply is further included; when a short circuit occurs in the protection circuit, the first fuse and the second fuse perform short circuit protection and trigger the detection circuit to detect.

[0046] Specifically, as Figure 1As shown, the short-circuit protection circuit further includes a second fuse F2 connected in series with the input power supply, one end of the second fuse F2 being connected to the positive pole of the input power supply V_in, and the other end being connected to the protection circuit and the power control switch S1. When the input power supply is abnormal, the protection circuit is short-circuited, and the first fuse F1 and the second fuse F2 in the front stage are used for short-circuit protection, and the detection circuit in the rear stage is triggered for detection, which includes a power input detection circuit and a current sampling circuit for detecting the voltage of the input power supply and the current in the circuit, respectively.

[0047] The front-stage fuse and the fuse connected in series with the protection device in the protection circuit in this embodiment can play a role in short-circuit protection when the protection circuit is short-circuited.

[0048] In some embodiments, the detection circuit further includes a relay switch; when the protection circuit is short-circuited, the relay switch is triggered to be closed; and the detection circuit is further configured to cut off the circuit through the power control switch according to an electrical signal generated by the closing of the relay switch.

[0049] Specifically, the detection circuit uses a control circuit detection form of a relay switch P1, the relay switch P1 being connected to the current sampling circuit I1 and the power input detection circuit V1, respectively, and being connected in parallel across the protection circuit through the current sampling circuit I1 and the power input detection circuit V1. When the protection circuit is short-circuited due to an abnormal input power supply or a too high surge level, there is a continuous current path on the protection path, which triggers the relay switch P1 to be closed, thereby forming a loop among the input power supply, the protection circuit and the detection circuit, and isolating the rear-stage circuit (including the power supply chip U1), and the relay switch P1 sends an electrical signal to the detection circuit after being closed, the detection circuit feeds back the received electrical signal to a processing platform, and the circuit is cut off through the power control switch S1, thereby preventing damage to the rear-stage circuit, especially when the abnormal input power supply is in a steady state and the fuse has not been fused, which can reduce the risk of equipment abnormality and improve the service life of the product.

[0050] The detection circuit using the relay switch in this embodiment can isolate the rear-stage circuit when the protection circuit is short-circuited, and can also cut off the circuit through the power control switch, thereby preventing damage to the rear-stage circuit.

[0051] In some embodiments, a filter circuit is further connected in parallel between the current sampling circuit and the power supply chip; the filter circuit includes a differential mode filter circuit and a common mode filter circuit, and is used for filter protection of the rear-stage circuit.

[0052] In some embodiments, the filter circuit includes a differential mode filter circuit and a common mode filter circuit, and is used for filter protection of the rear-stage circuit. Figure 1As shown, the filter circuit includes resistance R1, common mode inductor L2, differential mode inductor L1, and capacitors C3, C4, and C5; capacitor C5 is connected to the input side of common mode inductor L2, resistance R1, differential mode inductor L1, and capacitors C3 and C4 are connected to the output side of common mode inductor L2.

[0053] Specifically, a filter circuit is added in the post-stage circuit, which includes a differential mode filter circuit and a common mode filter circuit, wherein the differential mode filter circuit selects differential mode inductor L1 as the main filter, and the common mode filter circuit uses common mode inductor L2 and capacitor C5 in combination for filtering. The specific capacitance and inductance need to be adjusted according to the actual working frequency band of post-stage power supply chip U1 and the frequency of the wire near the power supply wire. Among them, capacitor C5 is connected in parallel between the detection circuit and common mode inductor L2, one end of resistance R1 is connected to the output side of common mode inductor L2, the other end is connected to power supply chip U1 through differential mode inductor L1, one end of capacitor C3 is connected between resistance R1 and differential mode inductor L1, and the other end is connected to common mode inductor L2. Capacitors C4 are connected in parallel across power supply chip U1.

[0054] By adding a filter circuit in the post-stage circuit in this embodiment for voltage protection and absorption, the post-stage circuit can be filtered and protected.

[0055] In some embodiments, a processing platform connected to the detection circuit is also included; the processing platform is used to control the power control switch to cut off the circuit according to the abnormal signals fed back by the power input detection circuit and the current sampling circuit, and trigger an alarm.

[0056] Specifically, the detected voltage and current abnormal signals are uploaded to the processing platform in real time by the detection circuit, and the processing platform is used for post-processing, control of the power control switch S1 to cut off the circuit, and triggering of an alarm to prompt the device that the input power is abnormal, thereby achieving maintenance and management of the electronic device and improving the reliability of the device operation.

[0057] The preferred embodiments are described and explained below.

[0058] In this embodiment, a short circuit protection circuit is provided, Figure 2 is a design framework diagram of the short circuit protection circuit in this embodiment, as Figure 2 shown, the design framework includes an input power, a protection circuit module, a power input detection module, a power control switch, a high pulse voltage absorption module, a current sampling module, a post-stage power supply module, a filter module, and a processing platform, and the specific connection relationship is as Figure 2 shown.

[0059] Wherein, for the input power access, the power input detection module and the current sampling module are added, and the short circuit protection is realized from two aspects. The detection data of the two parts are uploaded to the processing platform in real time, and the processing platform controls the input power through the power control switch. Moreover, the later power module is compatible, and the filter circuit is added in the later circuit. In the core protection circuit module, the protection scheme of the fuse and the clamping type protection device in series and the self-recovery method detection mechanism are adopted, and the high pulse voltage absorption module realized by the capacitor is also designed to absorb the voltage.

[0060] For the above design framework, Figure 1 is a schematic diagram of the short circuit protection circuit in the embodiment, as Figure 1 shown, including input power V_in, fuse F2, protection circuit, power control switch S1, power input detection circuit V1, current sampling circuit I1, relay switch P1, filter circuit and power chip U1.

[0061] Wherein, the protection circuit and the detection circuit are connected in sequence between the input power V_in and the power chip U1. The input power provides power for the entire circuit of the electronic device, and the later power chip is responsible for converting the input power into voltage and current suitable for the circuit or device.

[0062] The protection circuit is connected in parallel across the input power, including the series-connected fuse F1 and protection circuit D1, and the parallel-connected capacitors C1 and C2. The parallel-connected capacitors play a role in absorbing high pulse voltage, absorbing the voltage from the input power to the ground plane after the series-connected fuse F1 in the protection circuit, and preventing the final clamping voltage of the protection circuit from being too high after adding the fuse. The protection circuit D1 includes a clamping type protection device, the action voltage of which is higher than the voltage of the input power V_in, and the clamping voltage is lower than the protection voltage of the power chip U1. The fuse F2 is connected in series between the protection circuit and the input power V_in. When the protection circuit is short-circuited due to the access of abnormal input power, the short-circuit protection is performed by the fuses F1 and F2, and the detection of the later detection circuit is triggered.

[0063] The detection circuit includes a power input detection circuit V1, a current sampling circuit I1 and a relay switch P1. One end of the power input detection circuit V1 is connected to the positive pole of the input power V_in through a power control switch S1, and the other end is connected to the negative pole of the input power V_in, for real-time detection of the voltage of the input power and transmission to the processing platform. The current sampling circuit I1 is connected in parallel across the protection circuit. One end of the current sampling circuit I1 is connected to the positive pole of the input power V_in through the power control switch S1, and the other end is connected to the negative pole of the input power V_in through the relay switch P1, for real-time detection of the current signal in the circuit and transmission to the processing platform. When a transient high-voltage surge occurs, the fuse is blown to protect the protection device and the subsequent circuit, thereby providing surge protection. When a steady-state abnormal input power is connected, for example, a 24V, 220V steady-state abnormal power is connected to the 18V port, the fuse may be blown before the circuit is maintained in a short-circuit state. The fuse and the protection device provide circuit protection. Even if the protection device fails in a short-circuit state, the fuse in series with the protection device provides short-circuit protection to prevent the protection device and the subsequent circuit from being damaged by short-circuit. There is a continuous current path on the protection path, which corresponds to the triggering of the relay switch P1 to close. A loop is formed between the input power, the protection circuit and the detection circuit, which isolates the subsequent circuit. After the relay switch P1 is closed, an electrical signal is sent to the detection circuit, which feeds back the received electrical signal to the processing platform. The power control switch S1 is cut off to prevent damage to the subsequent circuit. This reduces the risk of equipment abnormalities and improves the service life of the product.

[0064] In addition, a filter circuit is added in parallel between the current sampling circuit and the power chip in the subsequent circuit. The filter circuit includes a differential mode filter circuit and a common mode filter circuit for filtering and protecting the subsequent circuit. The capacitor C5 is connected in parallel between the detection circuit and the common mode inductor L2. One end of the resistor R1 is connected to the output side of the common mode inductor L2, and the other end is connected to the power chip U1 through the differential mode inductor L1. One end of the capacitor C3 is connected between the resistor R1 and the differential mode inductor L1, and the other end is connected to the common mode inductor L2. The capacitor C4 is connected in parallel across the power chip U1. The differential mode filter circuit uses the differential mode inductor L1 as the main filter, and the common mode filter circuit uses the combination of the common mode inductor L2 and the capacitor C5 for filtering. The specific capacitance and inductance need to be adjusted according to the actual working frequency band of the subsequent power chip U1 and the frequency of the power supply wiring.

[0065] The processing platform is connected to the detection circuit and the subsequent power module (power chip U1), respectively, for controlling the power control switch S1 to cut off the circuit and triggering an alarm according to the abnormal signal fed back by the power input detection circuit and the current sampling circuit, prompting the abnormal input power of the electronic device, and realizing the maintenance and management of the electronic device to improve the reliability of the device operation.

[0066] At the same time, the PCB (Printed Circuit Board) design of the above protection circuit needs to meet the safety distance requirement, and the surge loop in the protection circuit is generally designed according to the 80 mil safety distance requirement. In particular, the power supply (i.e. input power supply) of sensitive components needs to be away from the surge loop or protection components, and sensitive signals need to be away from the surge loop and screw holes. Do not use the power supply related to the surge loop as a signal reference. In particular in the isolation design, the distance between the signals in the surge loop and all other signals needs to comply with the following design requirements. Different voltage levels correspond to different signal distances, for example, 1KV corresponds to a distance of 30-35 mil, 4KV corresponds to a distance of 180 mil, 2KV corresponds to a distance of 80 mil, and 6KV corresponds to a distance of 320 mil.

[0067] The following verifies the surge performance of the circuit in this embodiment:

[0068] In the verification test, the input power supply, signals and other functions should be used within their rated range and in normal working condition. According to the port type of the EUT (Equipment Under Test), select the corresponding test waveform generator, coupling unit and corresponding internal resistance of the signal source. According to the ports of the test equipment and their combinations, make the test equipment in typical working conditions.

[0069] During the surge test of the power supply terminal, the test voltage should be applied to the positive and negative peaks and zero crossing points of the alternating voltage waveform respectively. The power line and signal line should be subjected to pulse impact in different combinations of common mode and differential mode. Each combination state should be subjected to at least 5 pulse impacts. Each combination should test different pulse polarity, and the interval between two pulses should not be less than 1 minute.

[0070] The signal generator simulates the transient and lightning transient characteristics. For products used in different occasions and different ports of products, due to different corresponding surge transient waveforms, the parameters of the corresponding analog signal generator are also different. In general, 1.2 / 50us combined wave signal generator is used in AC and DC power supply ports and short distance signal circuit / line ports. In the test, 1.2 / 50us surge wave of 1KV, 1.5KV and 2KV is applied to the power input respectively, the internal resistance is 2 ohms, the voltage between the power input and the ground plane is grabbed respectively, the voltage between the protection circuit and the protection circuit is grabbed, and the feedback effect of the detection circuit is tested when the input is abnormal.

[0071] According to the measured results, the surge waveform obtained in the embodiment meets the normal surge input protection requirements. At the same time, by measuring the protection condition of the protection circuit when the power input is abnormal, it can be seen that a transient current will be generated across the protection circuit when the input is abnormal. The current signal is transmitted to the processing platform by using the current sampling circuit, and the processing platform will cut off the power supply in time after responding, so as to prevent the damage of the power supply module in the rear stage. When the normal power supply is used again, the equipment can be self-recovered and work normally.

[0072] In the embodiment, an electronic device is provided, which includes the short-circuit protection circuit in the above embodiment.

[0073] Through the short-circuit protection circuit, the circuit protection can be performed on the misconnected steady-state abnormal input power supply on the basis of the surge protection, and the management and maintenance are performed through the processing platform, so that the timeliness and accuracy of the electronic device fault problem processing are improved, unnecessary equipment maintenance, repair functions and labor cost investment are reduced, and the service life of the equipment is prolonged.

[0074] It should be understood that the specific embodiments described herein are only used to explain the application, but not to limit it. According to the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0075] Obviously, the drawings are only some examples or embodiments of the present application, and those of ordinary skill in the art can also apply the present application to other similar situations according to the drawings without creative labor. In addition, it can be understood that although the work done in the development process may be complex and long, some design, manufacture or production changes according to the technical content disclosed in the present application are only routine technical means for those of ordinary skill in the art, and should not be regarded as insufficient disclosure of the present application.

[0076] The term "embodiment" in the present application means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean independence or alternative to other embodiments. It can be clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in the present application can be combined with other embodiments without conflict.

[0077] The above embodiments only express several implementation ways of the present application, and the description is specific and detailed, but it should not be understood as a limitation to the patent protection scope. It should be pointed out that, for ordinary skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A short circuit protection circuit, characterized by, The application relates to a short-circuit protection circuit. The protection circuit comprises a first fuse and a protection circuit connected in series. The detection circuit comprises a power input detection circuit and a current sampling circuit. The power input detection circuit is connected in parallel with the input power supply. The current sampling circuit is connected in parallel with the protection circuit. The protection circuit further comprises a plurality of capacitors connected in parallel.

2. The short circuit protection circuit according to claim 1, characterized in that The protection circuit comprises a clamping protection device.

3. The short circuit protection circuit of claim 1, wherein The second fuse is connected in series with the input power supply.

4. The short circuit protection circuit of claim 1, wherein When the protection circuit is short-circuited, the first fuse and the second fuse are used for short-circuit protection, and the detection circuit is triggered for detection. The detection circuit further comprises a relay switch.

5. The short circuit protection circuit of claim 1, wherein When the protection circuit is short-circuited, the relay switch is triggered to be closed. The detection circuit is used for cutting off the circuit through the power control switch according to the electric signal generated by the closing of the relay switch. The filter circuit comprises a differential mode filter circuit and a common mode filter circuit.

6. The short circuit protection circuit of claim 1, wherein The filter circuit comprises a resistance, a common mode inductor, a differential mode inductor and a plurality of capacitors. The processing platform is connected with the detection circuit.

7. The short circuit protection circuit of claim 6, wherein The processing platform is used for controlling the power control switch to cut off the circuit according to the abnormal signal fed back by the power input detection circuit and the current sampling circuit, and triggering an alarm.

8. The short circuit protection circuit of claim 1, wherein, The application is suitable for the case of accessing a steady-state abnormal input power supply and the case of a transient high-voltage surge. The short-circuit protection circuit according to any one of claims 1 to 9.

9. The short circuit protection circuit of claim 1, wherein, ​ 10. An electronic device comprising: ​

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