Protection circuit and electronic device

Abstract

Disclosed in the present application are a protection circuit and an electronic device. The protection circuit comprises: a surge protection device, n fuses and a plurality of resistors, wherein each of the fuses is connected in series to (n-1) resistors of the plurality of resistors, and the n fuses connecting in series the (n-1) resistors are connected in parallel and connected to an input negative line of a protected device; and one end of the surge protection device is electrically connected to an input positive line of the protected device, and the other end thereof is electrically connected to (n-1) connection nodes, the (n-1) connection nodes comprising: a node where the first fuse is electrically connected to the first resistor, and the node where the ith resistor and the (i-1) th resistor of the (n-1) resistors connected in series to the ith fuse are electrically connected, where i=2, 3, …, n-1, and N is an integer greater than 1.

Description

Protective circuits and electronic equipment

[0001] Cross-references

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on November 22, 2023, with application number 202311565046.3 and invention name “Protective Circuit and Electronic Equipment”. The entire contents of the application are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of power supply technology, and in particular to a protection circuit and electronic equipment. Background Art

[0004] With the development of modern technology, electronic devices are becoming increasingly powerful, but this has also led to a sharp increase in power consumption. This is especially true in the field of communications equipment. Due to the increase in power consumption, the input current increases with power consumption while the supply voltage remains unchanged. Therefore, the existing single-fuse protection method also requires an increase in the selection of fuses.

[0005] However, high-current fuses can fail to open if the fault current is less than the rated current, or take too long to open if the fault current exceeds the rated current. These issues can cause smoke and fire at the equipment's fault point or printed circuit board (PCB), leading to serious accidents. Summary of the Invention

[0006] Embodiments of the present application provide a protection circuit and electronic equipment.

[0007] In the first aspect, an embodiment of the present application provides a protection circuit, comprising: a surge protection device, n fuses, and multiple resistors, wherein: each of the fuses is connected in series with (n-1) of the multiple resistors, and the n fuses of the (n-1) resistors in series are connected in parallel and connected to the negative input line of the protected device; one end of the surge protection device is electrically connected to the positive input line of the protected device, and the other end is electrically connected to (n-1) connection nodes, and the (n-1) connection nodes include: a node where the first fuse is electrically connected to the first resistor, and a node where the i-th resistor is electrically connected to the (i-1)th resistor among the (n-1) resistors connected in series with the i-th fuse, i = 2, 3,…, n-1, and n is an integer greater than 1.

[0008] In a second aspect, an embodiment of the present application provides an electronic device, which includes the protection circuit as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0010] FIG1 shows a schematic diagram of a protection circuit provided by an exemplary embodiment of the present application;

[0011] FIG2 shows a schematic diagram of another protection circuit provided by an exemplary embodiment of the present application;

[0012] FIG3 is a schematic diagram showing an application scenario of a protection circuit provided by an exemplary embodiment of the present application;

[0013] FIG4 is a schematic diagram showing another protection circuit application scenario provided by an exemplary embodiment of the present application;

[0014] FIG5 is a schematic diagram showing another application scenario of a protection circuit provided by an exemplary embodiment of the present application;

[0015] FIG6 is a schematic diagram showing another application scenario of a protection circuit provided by an exemplary embodiment of the present application;

[0016] FIG7 is a schematic diagram showing another application scenario of a protection circuit provided by an exemplary embodiment of the present application;

[0017] FIG8 is a schematic diagram showing another application scenario of a protection circuit provided by an exemplary embodiment of the present application;

[0018] FIG9 shows a schematic diagram of a protection circuit provided by an exemplary embodiment of the present application;

[0019] FIG10 shows a schematic diagram of another protection circuit provided by an exemplary embodiment of the present application;

[0020] FIG11 shows a schematic structural diagram of an electronic device provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0021] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0022] Figure 1 shows a schematic diagram of a protection circuit provided by an exemplary embodiment of the present application. Referring to Figure 1, the protection circuit 100 includes: a surge protection device 11, n fuses 12 and multiple resistors 13, wherein: each fuse 12 is connected in series with (n-1) of the multiple resistors 13, and the n fuses 12 connected in series with the (n-1) resistors 13 are connected in parallel and connected to the input negative line 14 of the protected device; one end of the surge protection device 11 is electrically connected to the input positive line 15 of the protected device, and the other end is electrically connected to (n-1) connection nodes, and the (n-1) connection nodes include: a node where the first fuse 1201 is electrically connected to the first resistor 1301, and a node where the i-th resistor is electrically connected to the (i-1)th resistor among the (n-1) resistors connected in series with the i-th fuse, where i = 2, 3, ..., n-1, and n is an integer greater than 1.

[0023] The resistor in the protection circuit of the embodiment of the present application can be a resistor in a practical sense, and can also be realized by setting the traces of a printed circuit board (PCB).

[0024] In the embodiment of the present application, when the surge protection device 11 fails and a short circuit occurs, a fault current will be generated. The fault current first flows from the surge protection device 11 through the node where the first fuse 1201 is electrically connected to the first resistor 1301, and then flows through the first fuse 1201, first blowing the first fuse 1201. The fault current also flows from the surge protection device 11 through the second connection node, through the first resistor connected in series with the second fuse, and then flows through the second fuse, at which time the second fuse is blown. By analogy, the fault current also flows from the surge protection device 11 through the i-th connection node, through the (i-1)th resistor, the (i-2)th resistor, ..., the first resistor connected in series with the i-th fuse, and then flows through the i-th fuse, at which time the i-th fuse is blown, and then the n-th fuse is blown, where i = 2, 3, ..., n-1, and n is an integer greater than 1. Therefore, through the protection circuit provided by the embodiment of the present application, the fault current can flow through n fuses in sequence due to the presence of a resistor in series with each fuse, and the n fuses are blown one after another, thereby reducing the current required to blow a single fuse and accelerating the blowing speed of the fuse.

[0025] FIG2 shows a schematic diagram of another protection circuit provided by an embodiment of the present application in one implementation. Referring to FIG2 , the protection circuit 100 includes a surge protection device 11, n fuses 12, and multiple resistors 13, and may also include a protection switch 16. One end of the protection switch 16 is electrically connected to the input positive line 15, and the other end is electrically connected to the (n-1) connection points. The protection switch 16 opens or closes the electrical connection between the two ends of the protection switch 16 under the control of a control signal.

[0026] The situations in which the protection switch 16 triggers the control signal include but are not limited to detecting a fault such as over-temperature, over-current, or over-voltage in the system.

[0027] In the embodiment of the present application, the protection switch 16 is connected in parallel with the surge protection device 11. In the event of a fault other than failure of the surge protection device 11 occurring in the protected device, the electrical connection between the two ends of the protection switch 16 is turned on by a control signal. The fault current generated by the other fault flows from the protection switch 16 through the node electrically connected between the first fuse 1201 and the first resistor 1301, through the first fuse 1201, and first blows the first fuse 1201. The fault current also flows from the protection switch 16 through the second connection node, through the first resistor connected in series with the second fuse, and then through the second fuse, at which point the second fuse blows. Similarly, through the protection circuit provided in the embodiment of the present application, the fault current flows through the protection switch 16, which is turned on by the control signal, through the resistors connected in series with each fuse, and then through each fuse, reaching n fuses in sequence, blowing n fuses one after another. This reduces the current required to blow a single fuse and speeds up the blowing of the fuses.

[0028] In one implementation, the surge protection device 11 may include at least one of the following: a transient voltage suppressor diode, a varistor, a gas discharge tube, and a surge suppression transistor.

[0029] FIG3 shows a schematic diagram of a protection circuit application scenario provided by an exemplary embodiment of the present application. Referring to FIG3 , the protection circuit in this embodiment includes a surge protection device, two fuses, and resistors connected in series with the two fuses, namely, fuse 311 and resistor 312, and fuse 321 and resistor 322. The surge protection device in this protection circuit is a transient voltage suppressor (TVS) diode 33.

[0030] FIG4 is a schematic diagram illustrating another application scenario of a protection circuit provided by an exemplary embodiment of the present application. Referring to FIG4 , the protection circuit in this embodiment includes a surge protection device, two fuses, and resistors connected in series with the two fuses, namely, fuse 411 and resistor 412, and fuse 421 and resistor 422. The surge protection device in this protection circuit is a varistor 43.

[0031] FIG5 is a schematic diagram illustrating another application scenario of a protection circuit provided by an exemplary embodiment of the present application. Referring to FIG5 , the protection circuit in this embodiment includes a surge protection device, two fuses, resistors connected in series with the two fuses, and a protection switch, namely, fuse 511 and resistor 512, and fuse 521 and resistor 522. The surge protection device in this protection circuit is a TVS 53, and the protection switches are field-effect transistors 541 and 542.

[0032] FIG6 shows a schematic diagram of another protection circuit application scenario provided by an exemplary embodiment of the present application. Referring to FIG6 , the protection circuit in this embodiment includes a surge protection device, two fuses, resistors connected in series with the two fuses, and a protection switch, namely, fuse 611 and resistor 612, and fuse 621 and resistor 622. The surge protection device in this protection circuit is a varistor 63, and the protection switches are field-effect transistors 641 and 642.

[0033] FIG7 shows a schematic diagram of another protection circuit application scenario provided by an exemplary embodiment of the present application. Referring to FIG7 , the protection circuit in this embodiment includes a surge protection device, two fuses, resistors connected in series with the two fuses, and a protection switch, namely, fuse 711 and resistor 712, and fuse 721 and resistor 722. The surge protection device in this protection circuit is a TVS 73, and the protection switch is a relay 74.

[0034] FIG8 is a schematic diagram illustrating another application scenario of a protection circuit provided by an exemplary embodiment of the present application. Referring to FIG8 , the protection circuit in this embodiment includes a surge protection device, two fuses, resistors connected in series with the two fuses, and a protection switch, namely, fuse 811 and resistor 812, and fuse 821 and resistor 822. The surge protection device in this protection circuit is a varistor 83, and the protection switch is a relay 84.

[0035] In one implementation, the electrical parameters of the n fuses in the protection circuit are the same.

[0036] In the protection circuit of the embodiment of the present application, the electrical parameters of the n fuses are set to be the same to ensure that when the circuit is working normally, the current of the branch where each fuse is located remains consistent, preventing the current of each branch from being unbalanced and affecting the protection accuracy of the protection circuit.

[0037] In one implementation, the parameters of the multiple resistors in the protection circuit are the same.

[0038] In the protection circuit of the embodiment of the present application, the parameters of multiple resistors in the protection circuit are set to be the same to ensure that when the circuit is operating normally, the currents in the branches where the fuses and the resistors connected in series with the fuses are located remain consistent, thereby preventing the currents in the branches from being unbalanced and affecting the protection accuracy of the protection circuit.

[0039] In one implementation, the nominal melting heat energy I2T in the electrical parameters of the fuse in the protection circuit is greater than the surge energy or power-on shock pulse energy of the input port of the protected device.

[0040] In the embodiment of the present application, the selection of the fuse in the protection circuit also needs to meet certain requirements. For example, the nominal melting heat energy I2T in the electrical parameters of the fuse needs to meet the surge current requirement. Specifically, the nominal melting heat energy I2T in the electrical parameters of the fuse can be greater than the surge energy or power-on shock pulse energy of the input port of the protected device.

[0041] In one implementation, the product of the rated current value in the electrical parameters of the fuse in the protection circuit, the n, and the derating factor is greater than the maximum input current of the protected device.

[0042] In an embodiment of the present application, the selection requirements for the fuse in the protection circuit may also include: the product of the rated current value in the fuse's electrical parameters, the value n, and the derating factor must be greater than the maximum input current of the protected device. For example, when n is 2 and the derating factor for parallel fuses is 0.85, the fuse's rated current value * 2 * 0.85 must be greater than the maximum input current of the protected device.

[0043] In one implementation, the n fuses in the protection circuit may be 2 fuses or 3 fuses, see FIG. 9 and FIG. 10 .

[0044] Figure 9 shows a schematic diagram of a protection circuit provided by an exemplary embodiment of the present application. In this embodiment, n=2, and the protection circuit includes three parts. The first part includes two fuses and resistors connected in series with the two fuses, namely fuse 911 and resistor 912, and fuse 921 and resistor 922. The resistor 912 and resistor 922 can be resistors in a practical sense, or they can be realized by setting the traces of the PCB. The second part includes a surge protection device 93, one end of which is connected to the access positive line 95, and the other end is connected to the connection node between the fuse 911 and the resistor 912. The third part includes a protection switch 94, one end of which is connected to the access positive line 95, and the other end is connected to the connection node between the fuse 911 and the resistor 912. The protection switch 94 is connected in parallel with the above-mentioned surge protection device 93.

[0045] In the embodiment of the present application, when surge protection device 93 in the protection circuit fails and a short circuit occurs, due to the presence of resistors 912 and 922, the fault current flows through surge protection device 93 and fuse 911, blowing fuse 911 first. After fuse 911 blows, the fault current also flows through surge protection device 93, resistor 912, resistor 922, and fuse 921, causing fuse 921 to blow last. Through the protection circuit of the embodiment of the present application, the fault current can reach fuse 911 and fuse 921 in sequence, thereby successively blowing fuse 911 and fuse 921, thereby reducing the current required to blow a single fuse and accelerating the blowing speed of the fuse.

[0046] In addition, the protection switch 94 is connected in parallel with the surge protection device 93. When other faults are detected in the protected equipment, the protection switch 94 is closed by triggering a control signal. Due to the presence of resistors 912 and 922, the fault current flows through the protection switch 94 and the fuse 911, and the fuse 911 is blown first. After the fuse 911 is blown, the fault current also flows through the protection switch 94, the resistor 912, the resistor 922 and the fuse 921, causing the fuse 921 to blow last. Through the protection circuit of the embodiment of the present application, the fault current can reach the fuse 911 and the fuse 921 in sequence, thereby successively blowing the fuse 911 and the fuse 921, thereby reducing the current required to blow a single fuse and accelerating the blowing speed of the fuse. Among them, the trigger control signal of the protection switch may include but is not limited to detecting faults such as overtemperature, overcurrent, and overvoltage in the system.

[0047] FIG10 shows a schematic diagram of another protection circuit provided by an exemplary embodiment of the present application. In this embodiment, n=3, and the protection circuit includes three parts. The first part includes three fuses and resistors connected in series with the three fuses, namely, fuse 101, resistor 111, and resistor 112; fuse 102, resistor 121, and resistor 122; and fuse 103, resistor 131, and resistor 132. The resistor can be a real resistor or can be implemented by setting a PCB trace. The second part includes a surge protection device 104, one end of which is connected to the access positive line 106, and the other end is connected to the connection node between fuse 101 and resistor 111, and is also connected to the connection node between resistor 121 and resistor 122. The third part includes a protection switch 105, one end of which is connected to the access positive line 106, and the other end is connected to the connection node between the fuse 101 and the resistor 111, and is also connected to the connection node between the resistor 121 and the resistor 122. The protection switch 105 is connected in parallel with the above-mentioned surge protection device 104.

[0048] In the embodiment of the present application, when the surge protection device 104 in the protection circuit fails and a short circuit occurs, due to the presence of resistors 111 and 112, resistors 121 and 122, and resistors 131 and 132, the fault current flows through the surge protection device 104 and fuse 101, first blowing fuse 101. After fuse 101 blows, the fault current also flows through the surge protection device 104, resistor 121, and fuse 102, causing fuse 102 to blow again. After fuse 102 blows, the fault current also flows through the surge protection device 104, resistor 122, resistor 132, resistor 131, and fuse 103, causing fuse 103 to blow last. Through the protection circuit of the embodiment of the present application, the fault current can reach fuse 101, fuse 102 and fuse 103 in sequence, thereby successively blowing fuse 101, fuse 102 and fuse 103, thereby reducing the current required to blow a single fuse and accelerating the blowing speed of the fuse.

[0049] In addition, for the protection switch 105 connected in parallel with the surge protection device 104, the protection steps when other faults of the protected equipment are detected are similar to those described above and are not described in detail here.

[0050] An embodiment of the present application further provides an electronic device, which includes a protection circuit as in any one of the embodiments shown in FIG. 1 to FIG. 10 .

[0051] Referring to FIG. 11 , in an embodiment of the present application, the protection circuit 1101 described in the above embodiments may be provided at the power input port 1102 of the electronic device 1100 , thereby enabling timely and rapid protection of the electronic device.

[0052] In addition, the electronic device may also be other high-current electronic devices, and the above-mentioned protection circuit may be provided at a power input port of the high-current electronic device.

[0053] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0054] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A protection circuit, comprising: Surge protection devices, n fuses and multiple resistors, including: Each of the fuses is connected in series with (n-1) of the multiple resistors, and the n fuses connected in series with the (n-1) resistors are connected in parallel and connected to the negative input line of the protected device; One end of the surge protection device is electrically connected to the input positive line of the protected device, and the other end is electrically connected to (n-1) connection nodes, wherein the (n-1) connection nodes include: a node where the first fuse is electrically connected to the first resistor, and a node where the i-th resistor is electrically connected to the (i-1)th resistor among the (n-1) resistors connected in series with the i-th fuse, i=2, 3, ..., n-1, where n is an integer greater than 1.

2. The protection circuit according to claim 1, wherein: Also includes: A protection switch, one end of which is electrically connected to the input positive line, and the other end of which is electrically connected to the (n-1) connection nodes. The protection switch switches on or off the electrical connection between the two ends of the protection switch under the control of a control signal.

3. The protection circuit according to claim 2, wherein: The protection switch includes one of the following: a field effect tube, a relay.

4. The protection circuit according to claim 1, wherein: The surge protection device includes at least one of the following: a transient voltage suppression diode, a varistor, a gas discharge tube, and a surge suppression transistor.

5. The protection circuit according to any one of claims 1 to 4, wherein: The electrical parameters of the n fuses are the same.

6. The protection circuit according to claim 5, wherein: The nominal melting heat energy I2T in the electrical parameters of the fuse is greater than the surge energy or power-on impact pulse energy of the input port of the protected device.

7. The protection circuit according to claim 5, wherein: The product of the rated current value in the electrical parameters of the fuse, the n and the derating factor is greater than the maximum input current of the protected device.

8. The protection circuit according to any one of claims 1 to 4, wherein: The parameters of the multiple resistors are the same.

9. The protection circuit according to claim 8, wherein: The n is equal to 2 or 3.

10. An electronic device comprising the protection circuit according to any one of claims 1 to 9.

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