Protection circuit and electronic equipment

Abstract

The invention discloses a protection circuit and electronic equipment, and the protection circuit comprises a first diode, and the positive electrode of the first diode is used for being connected with the output end of a power supply; one end of the first capacitor is connected with the negative electrode of the first diode, and the other end of the first capacitor is grounded; the driving end of the first switch tube is connected with the output end of a power supply, and the first end of the first switch tube is connected with the negative electrode of the first diode; the driving end of the second switching tube is connected with the second end of the first switching tube, the second end of the second switching tube is grounded, and the first end of the second switching tube is used for being connected with the enabling end of an external equipment current limiting switch of a mainboard connected with the power supply. On the basis of the mode, the situation that the current flows backwards to the mainboard by the external equipment can be prevented, so that the mainboard can be normally started after the power supply is recovered.

Description

Technical Field

[0001] The present application relates to the field of control technology, and in particular to protection circuits and electronic equipment. Background Art

[0002] In the prior art, computers usually connect external devices (such as USB devices) to the motherboard to expand functions. Existing external devices are usually not only powered by the electrical signals provided by the motherboard through the interface, but are also configured with corresponding external power supplies to ensure that the external devices can operate normally.

[0003] The defect of the prior art is that after the power supply of the computer is cut off or removed, the power supply no longer supplies power to the mainboard. Since the external device is usually equipped with a corresponding external power supply for power supply, it is easy for the external device to input backflow current to the mainboard through the corresponding interface of the mainboard. Since the backflow current is usually small, the current limiting switch on the corresponding interface cannot be triggered to disconnect, so that the backflow current is easy to flow into the mainboard when the power supply is not supplying power, causing the timing of the mainboard to be disordered after the power supply is restored, and the computer cannot be started normally. Summary of the invention

[0004] The main technical problem solved by the present application is how to prevent the external device from backflowing current to the mainboard, so that the mainboard can start up normally after the power supply is restored.

[0005] In order to solve the above technical problems, the first technical solution adopted in the present application is: a protection circuit, comprising: a first diode, the positive electrode of the first diode is used to connect to the output end of the power supply; a first capacitor, one end of the first capacitor is connected to the negative electrode of the first diode, and the other end of the first capacitor is grounded; a first switch tube, the driving end of the first switch tube is used to connect to the output end of the power supply, and the first end of the first switch tube is connected to the negative electrode of the first diode; the first switch tube is used to connect its first end and the second end when its driving end receives a low-level signal; a second switch tube, the driving end of the second switch tube is connected to the second end of the first switch tube, the second end of the second switch tube is grounded, and the first end of the second switch tube is used to connect to the enable end of the current limiting switch of the external device of the motherboard connected to the power supply; the second switch tube is used to connect its first end and the second end when its driving end receives a high-level signal.

[0006] Among them, the first end of the second switch tube is used to connect to the enable end of two or more external device current limiting switches of the mainboard connected to the power supply; the protection circuit also includes: at least one second diode, the positive electrode of a single second diode is used to connect to the enable end of the corresponding external device current limiting switch, and the negative electrode of the second diode is connected to the first end of the second switch tube.

[0007] The protection circuit further includes: a first resistor, one end of which is used to connect to the output end of the power supply, and the other end of which is respectively connected to the anode of the first diode and the driving end of the first switch tube.

[0008] The protection circuit further includes: a second resistor, one end of the second resistor is connected to the other end of the first resistor, and the other end of the second resistor is connected to the driving end of the first switch tube.

[0009] Among them, the protection circuit also includes: a third resistor, one end of the third resistor is connected to the other end of the first resistor, and the other end of the third resistor is connected to the positive electrode of the first diode; a fourth resistor, one end of the fourth resistor is connected to the other end of the third resistor, and the other end of the fourth resistor is grounded.

[0010] Among them, the protection circuit also includes: a fifth resistor, one end of the fifth resistor is connected to the second end of the first switch tube, and the other end of the fifth resistor is connected to the driving end of the second switch tube; a sixth resistor, one end of the sixth resistor is connected to the other end of the fifth resistor, and the other end of the sixth resistor is grounded.

[0011] The first end of the second switch tube is also used to connect to the discharge module connected to the mainboard.

[0012] The external device current limiting switch includes a current limiting switch of a USB device, and / or the power supply voltage of the power supply is greater than the power-on voltage of the USB device interface of the mainboard.

[0013] Wherein, the first switch tube is a triode, and / or the second switch tube is a field effect tube.

[0014] In order to solve the above technical problem, the second technical solution adopted in this application is: an electronic device, including the above protection circuit.

[0015] The beneficial effect of the present application lies in that, different from the prior art, in the technical solution of the present application, by setting a first diode, the power supply can charge the first capacitor when the power supply is normally supplied, and prevent the electric energy of the capacitor from flowing back to the power supply when the power supply is not supplied, and the first switch tube is turned on when the power supply is not supplied, so that one end of the first capacitor can provide a high-level signal to the driving end of the second switch tube to connect its first end and the second end, so that the enable end of the current limiting switch of the external device is grounded, thereby realizing the closing of the current limiting switch of the external device when the power supply is not supplied, disconnecting the connection between the external device and the mainboard, and preventing the external device from backflowing current to the mainboard when the power supply is not supplied, so that the mainboard can start up normally after the power supply is restored. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a structural schematic diagram of an embodiment of the protection circuit of the present application;

[0018] Figure 2 It is a structural schematic diagram of an embodiment of the electronic device of the present application.

[0019] In the figure: a first diode 101 , a first capacitor 102 , a first switch tube 103 , a second switch tube 104 , a second diode 105 , a first resistor 106 , a second resistor 107 , a third resistor 108 , a fourth resistor 109 , a fifth resistor 110 , and a sixth resistor 111 . DETAILED DESCRIPTION

[0020] The present application is further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only used to illustrate the present application, but are not intended to limit the scope of the present application. Similarly, the following examples are only some embodiments of the present application rather than all embodiments, and all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0021] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] In the description of this application, it is necessary to explain that, unless otherwise clearly specified and limited, the terms "install", "set", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or connected through an intermediate medium. For ordinary technicians in this field, the above-mentioned specific meanings belonging to this application can be connected according to specific circumstances.

[0023] This application proposes a protection circuit, see Figure 1 , Figure 1 is a schematic diagram of the structure of an embodiment of the protection circuit of the present application. Figure 1As shown, the protection circuit includes: a first diode 101 , a first capacitor 102 , a first switch tube 103 and a second switch tube 104 .

[0024] The anode of the first diode 101 is used to connect to the output end of the power supply.

[0025] The anode of the first diode 101 can be used to connect to the output end of the power supply, and the output end of the power supply can specifically refer to the output end of the power adapter. The power supply voltage output by the power adapter (such as Figure 1 The power supply voltage VIN) shown is typically 18 volts or other magnitudes.

[0026] The power supply can be used to supply power to the mainboard of the computer. In addition to being connected to the power supply, the mainboard of the computer can also be connected to one or more external devices. The external devices can have corresponding external power supplies, and the external devices can specifically be USB devices.

[0027] One end of the first capacitor 102 is connected to the cathode of the first diode 101 , and the other end of the first capacitor 102 is grounded.

[0028] Wherein, by setting the first diode 101, when the power supply is normally supplied, the first capacitor 102 can be charged by the power supply voltage VIN, so that the voltage at one end of the first capacitor 102 can reach the amplitude of the high level voltage.

[0029] When the power supply fails to supply power, for example, when the power supply fails, or the power supply is removed, or there is a power outage in the mains received by the power supply, the unidirectional conduction characteristic of the first diode 101 can prevent the current from flowing from the first capacitor 102 to the power supply, so that the first capacitor 102 can provide a high-level signal to the subsequent corresponding devices.

[0030] The driving end of the first switch tube 103 is used to connect to the output end of the power supply, and the first end of the first switch tube 103 is connected to the cathode of the first diode 101. The first switch tube 103 is used to conduct its first end and second end when its driving end receives a low level signal.

[0031] The first switch tube 103 is a switch tube that is turned on at a low level.

[0032] When the power supply is normal, the first end is disconnected from the second end, and when the power supply fails, the first end is connected to the second end, and the high level signal provided by one end of the first capacitor 102 can be output through the second end of the first switch tube 103.

[0033] The driving end of the second switch tube 104 is connected to the second end of the first switch tube 103, the second end of the second switch tube 104 is grounded, and the first end of the second switch tube 104 is used to connect to the enable end of the current limiting switch of the external device of the mainboard connected to the power supply. The second switch tube 104 is used to conduct its first end and the second end when its driving end receives a high level signal.

[0034] The second switch tube 104 is a switch tube that is turned on at a high level.

[0035] When the power supply fails to supply power, the second switch tube 104 can receive a high-level signal provided by the first capacitor 102, thereby conducting its first end and the second end, so that the enable end of the current limiting switch of the external device is grounded. For example, when the external device is a USB device, the enable end of the USB device current limiting switch set on the mainboard is grounded, thereby closing the electrical connection channel between the external device and the mainboard, preventing the external device from backflowing current to the mainboard through the current limiting switch, thereby reducing the possibility of timing disorder of the mainboard after the power supply is restored from being unable to power supply to normal power supply, and increasing the possibility of the mainboard being able to start normally after the power supply is restored to normal power supply.

[0036] It should be noted that the current limiting switch is usually set on or near the interface for connecting external devices on the mainboard, and is used to prevent the external device from inputting excessive current through the interface, or to prevent the mainboard from outputting excessive current through the interface, but the overcurrent threshold it triggers is relatively high, and it cannot trigger its own function of disconnecting the electrical connection when the backflow current of the external device is small. However, through the technical solution of the present application, when the power supply cannot be supplied, the electrical connection between the external device and the mainboard can be disconnected by pulling down the enable end of the current limiting switch of the external device, thereby preventing the current from backflowing into the mainboard and improving the reliability of the protection circuit.

[0037] Different from the prior art, in the technical solution of the present application, a first diode is set so that the power supply can charge the first capacitor when the power supply is normally supplied, and the electric energy of the capacitor is prevented from flowing back to the power supply when the power supply is not supplied. The first switch tube is turned on when the power supply is not supplied, so that one end of the first capacitor can provide a high-level signal to the driving end of the second switch tube to switch on its first end and the second end, so that the enable end of the current limiting switch of the external device is grounded, thereby turning off the current limiting switch of the external device when the power supply is not supplied, disconnecting the connection between the external device and the mainboard, and preventing the external device from backflowing current to the mainboard when the power supply is not supplied, so that the mainboard can start up normally after the power supply is restored.

[0038] In one embodiment, if Figure 1 As shown, the first end of the second switch tube 104 is used to connect to the enable ends of two or more external device current limiting switches of the mainboard to which the power supply is connected.

[0039] The protection circuit may further include at least one second diode 105 .

[0040] The anode of a single second diode 105 is used to connect to the enable terminal of the corresponding current limiting switch of the external device, and the cathode of the second diode 105 is connected to the first terminal of the second switch tube 104 .

[0041] Specifically, when the motherboard is connected to two or more external devices, for example Figure 1 As shown in the external device A1 and the external device A2, each external device is configured with a corresponding external device current limiting switch. If the enable end of each external device current limiting switch is directly connected to the first end of the second switch tube 104, it is possible that the voltages between the enable ends of the current limiting switches of different external devices will interfere with each other, affecting the stability and reliability of the protection circuit. Therefore, each external device can be configured with a second diode 105. The second diode 105 is used to allow the current passing through it to flow only from the enable end of the external device current limiting switch to the first end of the second switch tube 104, and cannot allow the current to flow from the enable end of one external device current limiting switch to the enable end of another external device current limiting switch. For example, the current cannot flow from the enable end of the current limiting switch of the external device A1 to the enable end of the current limiting switch of the external device A2.

[0042] Based on the above method, the protection circuit can control the current limiting switches of more than two external devices at the same time, so that a single protection circuit can prevent more than two external devices from backflowing current to the mainboard when the power supply cannot supply power, thereby improving the utilization rate of the protection circuit. At the same time, it also expands the applicable scenarios of the protection circuit and improves the applicability of the protection circuit.

[0043] In one embodiment, the protection circuit may further include a first resistor 106 .

[0044] One end of the first resistor 106 is used to connect to the output end of the power supply, and the other end of the first resistor 106 is connected to the anode of the first diode 101 and the driving end of the first switch tube 103 respectively.

[0045] Specifically, by setting the first resistor 106 and reasonably setting its resistance value, the current flowing to the first end and the driving end of the first switch tube 103 can be limited, thereby reducing the possibility of the signal provided by the power supply causing damage to the first switch tube 103 and improving the reliability of the protection circuit.

[0046] Optionally, the protection circuit may further include a second resistor 107 .

[0047] One end of the second resistor 107 is connected to the other end of the first resistor 106 , and the other end of the second resistor 107 is connected to the driving end of the first switch tube 103 .

[0048] Specifically, under the premise of providing the first resistor 106, a second resistor 107 may also be provided. By reasonably setting the resistance value of the second resistor 107, it is possible to further limit the voltage or current of the signal received by the driving end of the first switch tube 103, thereby avoiding damage thereto due to excessive current or voltage. At the same time, when the power supply is normally supplied, it is also possible to adjust the ratio between the currents flowing to the first capacitor 102 and the driving end of the first switch tube 103, thereby reducing the possibility of damage to the first diode 101 or the first switch tube 103 in the protection circuit due to excessive current or voltage, thereby further improving the reliability of the protection circuit.

[0049] Optionally, the protection circuit may further include a third resistor 108 and a fourth resistor 109 .

[0050] One end of the third resistor 108 is connected to the other end of the first resistor 106 , and the other end of the third resistor 108 is connected to the anode of the first diode 101 .

[0051] One end of the fourth resistor 109 is connected to the other end of the third resistor 108 , and the other end of the fourth resistor 109 is grounded.

[0052] Specifically, by reasonably setting the ratio between the resistance values ​​of the third resistor 108 and the fourth resistor 109, the maximum voltage that the first capacitor 102 can reach after charging can be limited, thereby reducing the possibility of the first capacitor 102 being damaged by excessive voltage, or the first capacitor 102 being damaged by excessive voltage, thereby further improving the reliability of the protection circuit.

[0053] In one embodiment, the protection circuit may further include a fifth resistor 110 and a sixth resistor 111 .

[0054] One end of the fifth resistor 110 is connected to the second end of the first switch tube 103 , and the other end of the fifth resistor 110 is connected to the driving end of the second switch tube 104 .

[0055] One end of the sixth resistor 111 is connected to the other end of the fifth resistor 110 , and the other end of the sixth resistor 111 is grounded.

[0056] Specifically, by reasonably setting the ratio between the fifth resistor 110 and the sixth resistor 111, the voltage between the driving end and the second end of the second switch tube 104 can be regulated to reduce the possibility of the second switch tube 104 being broken down or suffering other losses due to excessive voltage between the driving end and the second end of the second switch tube 104, thereby improving the reliability of the protection circuit.

[0057] In one embodiment, the first end of the second switch tube 104 is also used to connect to the discharge module connected to the mainboard.

[0058] Specifically, the module requiring discharge may specifically refer to a SUS power supply or other types of modules that require rapid discharge before the power supply resumes normal supply. The specific requirements may be determined according to actual needs and are not limited here.

[0059] Based on the above method, the protection circuit provided in the present application can also be used. When the power supply stops, the module to be discharged is grounded to quickly discharge the module to be discharged, thereby improving the discharge efficiency of the module to be discharged, thereby reducing the possibility that the mainboard cannot start normally after the power supply is restored, and improving the reliability of the protection circuit.

[0060] In one embodiment, the external device current limiting switch includes a current limiting switch of a USB device, and / or the supply voltage of the power supply is greater than the power-on voltage of the USB device interface of the mainboard.

[0061] Specifically, the power supply voltage is greater than the maximum voltage of the current signal that can be fed back to the motherboard by the external device connected to the motherboard. Usually, this maximum voltage is the maximum voltage limited by the interface connecting the motherboard to the corresponding external device. For example, the maximum voltage of a USB device is usually 5V.

[0062] For example, when the power source is a power adapter, the power supply voltage may be 18V, and the power-on voltage of the USB device interface is usually 5V. The above is only an example. In practice, there may be other voltage combinations that meet the above requirements, which are not limited here.

[0063] In one embodiment, the first switch tube 103 is a triode, and / or the second switch tube 104 is a field effect tube.

[0064] Specifically, the first switch tube 103 may be a triode, which has a small input impedance and a large current flowing therethrough, and can ensure that a high-level signal is transmitted to the driving end of the second switch tube 104 when the first switch tube 103 is turned on.

[0065] When the second switch tube 104 can be a triode, the first switch tube 103 does not need to be configured with a corresponding pull-down resistor for protection. When the first switch tube is a field effect tube, it has stronger stability, which can improve the stability and reliability of the protection circuit and reduce the possibility of failure of the second switch tube 104.

[0066] This application also proposes an electronic device, see Figure 2 , Figure 2 is a schematic diagram of the structure of an embodiment of the electronic device of the present application, such as Figure 2 As shown, the electronic device 20 includes a protection circuit 21. The protection circuit 21 can be any protection circuit described in the above embodiments, which will not be described in detail here.

[0067] The electronic device 20 can specifically be a computer to which the motherboard connected to the power supply belongs, or it can be other types of electronic devices that are connected to the power supply and external devices respectively and have corresponding external device current limiting switches. The specific requirements can be determined according to actual needs and are not limited here.

[0068] Different from the prior art, in the technical solution of the present application, a first diode is set so that the power supply can charge the first capacitor when the power supply is normally supplied, and the electric energy of the capacitor is prevented from flowing back to the power supply when the power supply is not supplied. The first switch tube is turned on when the power supply is not supplied, so that one end of the first capacitor can provide a high-level signal to the driving end of the second switch tube to switch on its first end and the second end, so that the enable end of the current limiting switch of the external device is grounded, thereby turning off the current limiting switch of the external device when the power supply is not supplied, disconnecting the connection between the external device and the mainboard, and preventing the external device from backflowing current to the mainboard when the power supply is not supplied, so that the mainboard can start up normally after the power supply is restored.

[0069] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradicting each other.

[0070] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0071] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0072] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (which can be a personal computer, server, network device or other system that can fetch instructions from the instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0073] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A protection circuit, characterized in that: include: a first diode, wherein the anode of the first diode is used to be connected to the output end of the power supply; a first capacitor, one end of the first capacitor being connected to the cathode of the first diode, and the other end of the first capacitor being grounded; A first switch tube, wherein the driving end of the first switch tube is used to connect to the output end of the power supply, and the first end of the first switch tube is connected to the cathode of the first diode; wherein the first switch tube is used to conduct the first end and the second end thereof when the driving end thereof receives a low level signal; A second switch tube, wherein the driving end of the second switch tube is connected to the second end of the first switch tube, the second end of the second switch tube is grounded, and the first end of the second switch tube is used to connect to the enable end of the current limiting switch of the external device of the mainboard connected to the power supply; the second switch tube is used to conduct the first end and the second end when the driving end thereof receives a high level signal.

2. The protection circuit according to claim 1, characterized in that: The first end of the second switch tube is used to connect to the enable ends of two or more external device current limiting switches of the mainboard connected to the power supply; The protection circuit further comprises: At least one second diode, the anode of a single second diode is used to connect to the enable end of the corresponding current limiting switch of the external device, and the cathode of the second diode is connected to the first end of the second switch tube.

3. The protection circuit according to claim 1 or 2, characterized in that: The protection circuit further comprises: A first resistor, one end of the first resistor is used to connect to the output end of the power supply, and the other end of the first resistor is respectively connected to the anode of the first diode and the driving end of the first switch tube.

4. The protection circuit according to claim 3, characterized in that: The protection circuit further comprises: A second resistor, one end of the second resistor is connected to the other end of the first resistor, and the other end of the second resistor is connected to the driving end of the first switch tube.

5. The protection circuit according to claim 3, characterized in that: The protection circuit further comprises: a third resistor, one end of the third resistor being connected to the other end of the first resistor, and the other end of the third resistor being connected to the anode of the first diode; a fourth resistor, one end of the fourth resistor being connected to the other end of the third resistor, and the other end of the fourth resistor being grounded.

6. The protection circuit according to claim 1 or 2, characterized in that: The protection circuit further comprises: a fifth resistor, one end of the fifth resistor being connected to the second end of the first switch tube, and the other end of the fifth resistor being connected to the driving end of the second switch tube; A sixth resistor, one end of the sixth resistor is connected to the other end of the fifth resistor, and the other end of the sixth resistor is grounded.

7. The protection circuit according to claim 1 or 2, characterized in that: The first end of the second switch tube is also used to connect to the discharge module connected to the mainboard.

8. The protection circuit according to claim 1 or 2, characterized in that: The external device current limiting switch includes a current limiting switch of a USB device, and / or the power supply voltage of the power supply is greater than the power-on voltage of the USB device interface of the mainboard.

9. The protection circuit according to claim 1 or 2, characterized in that: The first switch tube is a triode, and / or the second switch tube is a field effect tube.

10. An electronic device, characterized in that: The invention comprises a protection circuit as claimed in any one of claims 1 to 9.

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