Short circuit protection circuit

Abstract

The utility model provides a short-circuit protection circuit, and belongs to the technical field of electronic power processing. The short-circuit protection circuit comprises a control module, a voltage division module, a switch module and a sampling resistor, the output end of the control module is connected with the control end of the switch module, the sampling end of the control module is connected with the first end of the voltage dividing module, the second end of the voltage dividing module is connected with one end of the sampling resistor, one end of the sampling resistor is further connected with the first end of the switch module, and the second end of the switch module is used for being connected with a load. The other end of the sampling resistor, the third end of the voltage dividing module and the grounding end of the control module are all grounded, and the control module controls on-off of the switch module based on voltage signals sampled by the sampling end. According to the invention, the temperature drift influence of the sampling resistor can be avoided, so that the short-circuit detection signal precision is improved.

Description

TECHNICAL FIELD

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

[0002] Short-circuit protection is a vital protection measure in electrical systems, which is mainly used to prevent the serious consequences that may be caused by the abnormal increase of current when a short-circuit fault occurs in a circuit. Short-circuit refers to the abnormal conduction between two circuit nodes or multiple circuit nodes in a circuit, which is usually caused by insulation damage, wiring errors, and electronic component failure. When a short-circuit fault occurs in a circuit, the current will increase sharply, far exceeding the current carrying capacity of the circuit and electronic equipment. At this time, the circuit of the short-circuit part needs to be immediately cut off to ensure the safety and reliability of the circuit.

[0003] In related technologies, there are mainly three ways of short-circuit protection. The first way is realized by overcurrent protection components such as fuses. The second way is realized by building a short-circuit protection circuit with discrete components. The third way is realized by building an overcurrent protection circuit with an integrated chip. Among them, short-circuit protection is usually realized by monitoring the changes of current or voltage in the circuit in real time to determine whether there is a short-circuit fault in the circuit. When a short-circuit fault occurs in the circuit, the circuit will quickly cut off the power supply or take other measures to further prevent damage caused by excessive current.

[0004] However, when short-circuit protection is based on related technologies, the temperature drift of the sampling resistor will cause the short-circuit protection circuit to have an error protection action, and a large current will cause a large power loss on the sampling resistor. Therefore, the related technology solution has the problem of being affected by the temperature drift of the sampling resistor and low accuracy of the short-circuit detection signal. CONTENT OF THE INVENTION

[0005] The purpose of the present application is to provide a short-circuit protection circuit that can avoid the influence of temperature drift of the sampling resistor, thereby improving the accuracy of the short-circuit detection signal.

[0006] The embodiments of the present application are implemented as follows:

[0007] In a first aspect, the present application provides a short-circuit protection circuit, which comprises a control module, a voltage dividing module, a switching module, and a sampling resistor.

[0008] The output end of the control module is connected to the control end of the switching module, the sampling end of the control module is connected to the first end of the voltage dividing module, one end of the sampling resistor is connected to the second end of the voltage dividing module, and the other end of the sampling resistor is connected to the first end of the switching module. The second end of the switching module is used to connect a load.

[0009] The other end of the sampling resistor, the third end of the voltage dividing module and the ground end of the control module are grounded, and the control module controls the on-off of the switch module based on the voltage signal sampled by the sampling end.

[0010] As a possible implementation, the control module comprises a single-chip microcomputer.

[0011] The output end of the single-chip microcomputer is connected with the control end of the switch module, and the sampling end of the single-chip microcomputer is connected with the first end of the voltage dividing module.

[0012] The ground end of the single-chip microcomputer, the third end of the voltage dividing module and the other end of the sampling resistor are grounded.

[0013] As a possible implementation, the switch module comprises a metal oxide semiconductor field effect transistor.

[0014] The gate of the metal oxide semiconductor field effect transistor is connected with the output end of the single-chip microcomputer, the source of the metal oxide semiconductor field effect transistor is connected with one end of the sampling resistor and the second end of the voltage dividing module, and the drain of the metal oxide semiconductor field effect transistor is used for connecting the load.

[0015] As a possible implementation, the voltage dividing module comprises a first resistor and a second resistor.

[0016] One end of the first resistor and one end of the second resistor are connected with the sampling end of the single-chip microcomputer, the other end of the first resistor is connected with the source of the metal oxide semiconductor field effect transistor and one end of the sampling resistor respectively, and the other end of the second resistor is grounded.

[0017] As a possible implementation, the short-circuit protection circuit further comprises a voltage stabilizing module.

[0018] The first end of the voltage stabilizing module is connected with the second end of the voltage dividing module, the second end of the voltage stabilizing module is connected with one end of the sampling resistor, and the third end of the voltage stabilizing module is grounded.

[0019] As a possible implementation, the voltage stabilizing module comprises a voltage stabilizing diode and a third resistor.

[0020] The anode of the voltage stabilizing diode is connected with the second end of the voltage dividing module, and the cathode of the voltage stabilizing diode is connected with the first end of the switch module and one end of the sampling resistor respectively.

[0021] The anode of the voltage stabilizing diode is also connected with one end of the third resistor, and the other end of the third resistor is used for grounding.

[0022] As a possible implementation, the short-circuit protection circuit further comprises a protection module.

[0023] The input end of the protection module is connected with the first end of the switch module and one end of the sampling resistor respectively, and the output end of the protection module is connected with the cathode of the voltage stabilizing diode.

[0024] As a possible implementation manner, the protection module comprises a diode.

[0025] The input end of the diode is connected with the output end of the switch module and one end of the sampling resistor respectively, and the output end of the diode is connected with the cathode of the voltage stabilizing diode.

[0026] As a possible implementation manner, the short-circuit protection circuit further comprises a filtering module.

[0027] One end of the filtering module is connected with one end of the first resistor and one end of the second resistor respectively, and the other end of the filtering module is grounded.

[0028] As a possible implementation manner, the filtering module comprises a capacitor.

[0029] One end of the capacitor is connected with one end of the first resistor and one end of the second resistor respectively, and the other end of the capacitor is grounded.

[0030] The beneficial effects of the embodiments of the present application include:

[0031] The short-circuit protection circuit provided by the embodiments of the present application is composed of a control module, a voltage dividing module, a switch module and a sampling resistor, wherein the output end of the control module is connected with the control end of the switch module, the sampling end of the control module is connected with the first end of the voltage dividing module, the control module controls the on-off of the switch module based on the sampled voltage signal, so as to realize the short-circuit protection of the circuit; one end of the sampling resistor is connected with the second end of the voltage dividing module, and the other end of the sampling resistor is also connected with the first end of the switch module, the second end of the switch module is used for connecting a load, the voltage dividing module can divide the voltage of the sampling resistor, and send the divided voltage signal to the sampling end of the control module, which can effectively improve the precision of the sampling signal of the control module, and further avoid the false operation of the control module; the grounding end of the control module, the other end of the sampling resistor and the third end of the voltage dividing module are all grounded. In this way, the effect of avoiding the temperature drift of the sampling resistor and improving the precision of the short-circuit detection signal can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0033] Figure 1An existing short-circuit protection circuit;

[0034] Figure 2 A structure diagram of a first short-circuit protection circuit provided by an embodiment of the present application;

[0035] Figure 3 A structure diagram of a second short-circuit protection circuit provided by an embodiment of the present application;

[0036] Figure 4 A structure diagram of a third short-circuit protection circuit provided by an embodiment of the present application;

[0037] Figure 5 A structure diagram of a fourth short-circuit protection circuit provided by an embodiment of the present application;

[0038] Figure 6 A structure diagram of a fifth short-circuit protection circuit provided by an embodiment of the present application;

[0039] Figure 7 A structure diagram of a sixth short-circuit protection circuit provided by an embodiment of the present application;

[0040] Figure 8 A structure diagram of a seventh short-circuit protection circuit provided by an embodiment of the present application;

[0041] Figure 9 A structure diagram of an eighth short-circuit protection circuit provided by an embodiment of the present application;

[0042] Figure 10 A structure diagram of a ninth short-circuit protection circuit provided by an embodiment of the present application;

[0043] Figure 11 A simulation waveform diagram of a short-circuit protection circuit provided by an embodiment of the present application;

[0044] Figure 12 A simulation waveform diagram of another short-circuit protection circuit provided by an embodiment of the present application.

[0045] BRIEF DESCRIPTION OF DRAWINGS: 101: control module; 1011: single-chip microcomputer; 102: voltage division module; 1021: first resistor; 1022: second resistor; 103: switch module; 1031: metal oxide semiconductor field effect transistor; 104: sampling resistor; 105: voltage stabilization module; 1051: voltage stabilization diode; 1052: third resistor; 106: protection module; 1061: diode; 107: filter module; 1071: capacitor. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0048] It should be noted that similar reference numerals and letters refer to similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0049] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0050] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0051] In the description of the present application, it should also be noted that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements inside. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] Currently, there are three main methods for short-circuit protection in circuits: the first is to use overcurrent protection components, the second is to build a short-circuit protection circuit using discrete components, and the third is to implement the overcurrent protection circuit using an integrated chip. The second method is the most common, and it determines whether a short-circuit fault has occurred by monitoring changes in the current or voltage in the circuit in real time. If a short-circuit fault occurs, the power supply is quickly cut off or other protective measures are taken to prevent damage to the circuit due to excessive current. However, this solution is susceptible to temperature drift of the sampling resistor, which can cause the short-circuit protection circuit to erroneously activate, resulting in inaccurate sampling voltage and affecting the accuracy of the short-circuit protection voltage detection signal.

[0053] To this end, an embodiment of the present application provides a short-circuit protection circuit, which is composed of a control module, a voltage divider module, a switch module, and a sampling resistor. The output end of the control module is connected to the control end of the switch module, the sampling end of the control module is connected to the first end of the voltage divider module, the second end of the voltage divider module is connected to one end of the sampling resistor, one end of the sampling resistor is also connected to the first end of the switch module, and the second end of the switch module is used to connect to a load. The control module controls the on and off of the switch module based on the voltage signal sampled by the sampling end, so that when a short circuit fault occurs in the circuit, the load is quickly short-circuited. The control module samples the voltage divider signal output by the voltage divider module. In this way, the influence of temperature drift of the sampling resistor can be avoided, thereby improving the accuracy of the short-circuit detection signal.

[0054] The short-circuit protection circuit provided in the embodiments of the present application is explained in detail below with reference to the accompanying drawings.

[0055] Figure 1 This is an existing short-circuit protection circuit, see Figure 1 , Figure 1 This short-circuit protection circuit is constructed using discrete components and includes: a resistor R1, a resistor R2, a Schottky diode D1, a resistor R3, a metal-oxide-semiconductor field-effect transistor Q1, and a transistor Q2. The collector of transistor Q2 and one end of resistor R1 are both connected to a power source. The base of transistor Q2, one end of resistor R2, the cathode of Schottky diode D1, and the source of metal-oxide-semiconductor field-effect transistor Q1 are all connected to the other end of resistor R1. The drain of metal-oxide-semiconductor field-effect transistor Q1 serves as the output of the short-circuit protection circuit. The emitter of transistor Q2, the other end of resistor R2, the anode of Schottky diode D1, and the gate of metal-oxide-semiconductor field-effect transistor Q1 are all connected to one end of resistor R3. The other end of resistor R3 is grounded.

[0056] It is worth mentioning that the resistance R1 is used as a sampling resistance in the short circuit protection circuit. When the circuit is working normally, the current is not enough to generate a voltage drop on the resistance R1 to turn on the transistor Q2 because the resistance R1 has a small resistance value. However, when the circuit has a short circuit fault, the circuit current will abnormally increase, and the voltage drop generated on the resistance R1 is enough to turn on the transistor Q2, so that the gate voltage of the metal oxide semiconductor field effect transistor Q1 is higher than the source voltage, and the metal oxide semiconductor field effect transistor Q1 is turned off, thereby achieving short circuit protection for the load.

[0057] Figure 2 A structural schematic diagram of a short circuit protection circuit is provided in the present application, as shown in Figure 2 The embodiment of the present application provides a short circuit protection circuit, which comprises a control module 101, a voltage division module 102, a switch module 103 and a sampling resistance 104.

[0058] The output end of the control module 101 is connected with the control end of the switch module 103, the sampling end of the control module 101 is connected with the first end of the voltage division module 102, the second end of the voltage division module 102 is connected with one end of the sampling resistance 104, and the other end of the sampling resistance 104 is also connected with the first end of the switch module 103, and the second end of the switch module 103 is used for connecting a load.

[0059] Optionally, the output end of the control module 101 is connected with the control end of the switch module 103, the sampling end of the control module 101 obtains the voltage signal of the sampling resistance 104 through the voltage division module 102, the control module 101 determines whether the circuit has a short circuit fault based on the voltage signal sampled by the sampling end, and when the control module 101 determines that the circuit has a short circuit fault, the control module 101 outputs a corresponding driving signal through the output end to control the switch module 103 to be turned off, so as to realize the short circuit protection function.

[0060] Optionally, the sampling end of the control module 101 is connected with the first end of the voltage division module 102, the second end of the voltage division module 102 is connected with one end of the sampling resistance 104, and the third end of the voltage division module 102 is grounded, that is, the first end of the voltage division module 102 is used as the output end of the voltage division module 102, the voltage division module 102 sends a voltage division signal to the control module 101 through the first end; the second end of the voltage division module 102 is used as the input end of the voltage division module 102, and the voltage division module 102 obtains the terminal voltage of the sampling resistance 104 through the second end; and the third end of the voltage division module 102 is used as the ground end of the voltage division module 102, so that the voltage division module 102 can release the excess charge obtained by the voltage division module 102.

[0061] Optionally, one end of the sampling resistor 104 is connected with the second end of the voltage dividing module 102 and the first end of the switch module 103 respectively, the second end of the switch module 103 is used for connecting the load, and the load is also directly connected with the power supply. When the circuit is normally operated, the power supply voltage is approximately applied on the load, the voltage on the sampling resistor 104 is extremely small, the voltage signal sampled by the control module 101 is also extremely small, the control module 101 controls the switch module 103 to be turned on, and the load is normally operated. However, when the circuit has a short circuit fault, the load is equivalent to a wire, and the power supply voltage is approximately applied on the sampling resistor 104. After the voltage on the sampling resistor 104 is divided by the voltage dividing module 102, the voltage signal is transmitted to the sampling end of the control module 101. The control module 101 controls the switch module 103 to be turned off based on the voltage signal sampled, so as to realize the short circuit protection of the circuit.

[0062] The other end of the sampling resistor 104, the third end of the voltage dividing module 102 and the grounding end of the control module 101 are all grounded. The control module 101 controls the on-off of the switch module 103 based on the voltage signal sampled by the sampling end.

[0063] Optionally, the other end of the sampling resistor 104, the third end of the voltage dividing module 102 and the grounding end of the control module 101 are all grounded, so that the short circuit protection circuit itself forms a complete circuit loop.

[0064] Optionally, the sampling end of the control module 101 is used for sampling the voltage dividing signal output by the voltage dividing module 102, which can effectively avoid the influence of the temperature drift of the sampling resistor 104, improve the precision of the sampling signal of the sampling end, and effectively avoid the impact of high voltage on the control module 101, so as to further protect the safety of the operation of the short circuit protection circuit.

[0065] In the embodiment of the present application, the short circuit protection circuit is composed of a control module, a voltage dividing module, a switch module and a sampling resistor. The output end of the control module is connected with the control end of the switch module, the sampling end of the control module is connected with the first end of the voltage dividing module, the control module controls the on-off of the switch module based on the voltage signal sampled, so as to realize the short circuit protection of the circuit. The second end of the voltage dividing module is connected with one end of the sampling resistor, and the other end of the sampling resistor is also connected with the first end of the switch module. The second end of the switch module is used for connecting the load. The voltage dividing module can divide the terminal voltage of the sampling resistor, and transmit the voltage signal after voltage division to the sampling end of the control module, which can effectively improve the precision of the sampling signal of the control module, and avoid the false operation of the control module. The grounding end of the control module, the other end of the sampling resistor and the third end of the voltage dividing module are all grounded. In this way, the influence of the temperature drift of the sampling resistor can be avoided, so as to improve the precision of the short circuit detection signal.

[0066] In an alternative implementation, referring to Figure 3 The control module 101 in the short-circuit protection circuit provided by the embodiments of the present application comprises a single-chip microcomputer 1011.

[0067] Optionally, the control module 101 in the short-circuit protection circuit is implemented by the single-chip microcomputer 1011, which can be any model of integrated circuit chip, and the present application does not make a specific limitation in this regard.

[0068] The output end of the single-chip microcomputer 1011 is connected with the control end of the switch module 103, and the sampling end of the single-chip microcomputer 1011 is connected with the first end of the voltage dividing module 102.

[0069] Optionally, the output end of the single-chip microcomputer 1011 is connected with the control end of the switch module 103, and the output end of the single-chip microcomputer 1011 can be any signal output pin on the integrated circuit chip. The single-chip microcomputer 1011 can output a pulse signal corresponding to a high level or a low level to the switch module 103 via the output end, so as to make the switch module 103 conduct or disconnect under the action of the pulse signal.

[0070] Optionally, the sampling end of the single-chip microcomputer 1011 can be implemented by any signal input pin on the integrated circuit chip. The single-chip microcomputer 1011 receives the voltage signal output by the voltage dividing module 102 via the sampling end, and controls the pulse signal output by the output end based on the voltage signal sampled by the sampling end, so as to control the on-off of the switch module 103.

[0071] The ground end of the single-chip microcomputer 1011, the third end of the voltage dividing module 102, and the other end of the sampling resistor 104 are all grounded.

[0072] Optionally, the ground end of the single-chip microcomputer 1011, the third end of the voltage dividing module 102, and the other end of the sampling resistor 104 are all grounded, which can effectively prevent electrostatic damage and protect the operation safety and reliability of the short-circuit protection circuit.

[0073] In an alternative implementation, referring to Figure 4 The switch module 103 in the short-circuit protection circuit provided by the embodiments of the present application comprises a metal oxide semiconductor field effect transistor 1031.

[0074] Optionally, the switch module 103 in the short-circuit protection circuit can be implemented by the metal oxide semiconductor field effect transistor 1031, which can be a P-type metal oxide semiconductor field effect transistor or an N-type metal oxide semiconductor field effect transistor, and the present application does not make a specific limitation in this regard.

[0075] The gate of the metal oxide semiconductor field effect transistor 1031 is connected with the output end of the single-chip microcomputer 1011, the source of the metal oxide semiconductor field effect transistor 1031 is connected with one end of the sampling resistor 104 and the second end of the voltage dividing module 102, and the drain of the metal oxide semiconductor field effect transistor 1031 is used for connecting a load.

[0076] Optionally, the single-chip microcomputer 1011 controls the gate voltage of the metal oxide semiconductor field effect transistor 1031 through the output end of the single-chip microcomputer 1011 based on the high and low of the voltage signal sampled by the sampling end, the source of the metal oxide semiconductor field effect transistor 1031 is connected with one end of the sampling resistor 104, and the metal oxide semiconductor field effect transistor 1031 is turned on or turned off under the action of the gate-source voltage.

[0077] In an optional embodiment, referring to Figure 5 The voltage dividing module 102 in the short-circuit protection circuit provided by the embodiment of the application comprises a first resistor 1021 and a second resistor 1022.

[0078] One end of the first resistor 1021 and one end of the second resistor 1022 are connected with the sampling end of the single-chip microcomputer 1011, the other end of the first resistor 1021 is connected with the source of the metal oxide semiconductor field effect transistor 1031 and one end of the sampling resistor 104 respectively, and the other end of the second resistor 1022 is grounded.

[0079] Optionally, the other end of the first resistor 1021 is connected with one end of the sampling resistor 104, the first resistor 1021 obtains the terminal voltage of the sampling resistor 104 through the other end, one end of the first resistor 1021 and one end of the second resistor 1022 are connected with the sampling end of the single-chip microcomputer 1011, and the first resistor 1021 and the second resistor 1022 transmit the terminal voltage of the sampling resistor 104 to the sampling end of the single-chip microcomputer 1011 after voltage dividing. When a short-circuit fault exists in the circuit, the single-chip microcomputer 1011 controls the metal oxide semiconductor field effect transistor 1031 to be turned off through the output end of the single-chip microcomputer 1011 after recognizing the high-level signal of the short-circuit fault, so as to realize short-circuit protection.

[0080] In an optional embodiment, referring to Figure 6 The short-circuit protection circuit provided by the embodiment of the application further comprises a voltage stabilizing module 105.

[0081] The first end of the voltage stabilizing module 105 is connected with the second end of the voltage dividing module 102, the second end of the voltage stabilizing module 105 is connected with one end of the sampling resistor 104, and the third end of the voltage stabilizing module 105 is grounded.

[0082] Optionally, the first end of the voltage stabilizing module 105 is connected with the second end of the voltage dividing module 102, and the second end of the voltage stabilizing module 105 is connected with one end of the sampling resistor 104, so that the voltage stabilizing module 105 can effectively prevent the impact of unstable voltage of the front-stage circuit on the voltage dividing module 102 and the single-chip microcomputer 1011.

[0083] In an optional implementation, referring to Figure 7 The voltage stabilizing module 105 in the short-circuit protection circuit provided by the embodiment of the application comprises a voltage stabilizing diode 1051 and a third resistor 1052.

[0084] The anode of the voltage stabilizing diode 1051 is connected with the second end of the voltage dividing module 102, and the cathode of the voltage stabilizing diode 1051 is connected with the first end of the switch module 103 and one end of the sampling resistor 104 respectively.

[0085] Optionally, the anode of the voltage stabilizing diode 1051 is connected with the second end of the voltage dividing module 102, and the cathode of the voltage stabilizing diode 1051 is connected with the first end of the switch module 103 and one end of the sampling resistor 104 respectively, so that the voltage stabilizing diode 1051 can reduce the voltage sampled by the sampling resistor 104 when the circuit is short-circuited, for example, the voltage sampled by the sampling resistor 104 is 24V, the voltage stabilizing value of the voltage stabilizing diode 1051 is 20V, and the voltage of the anode of the voltage stabilizing diode 1051 is 4V.

[0086] It is worth noting that the voltage stabilizing signal input by the voltage stabilizing diode 1051 into the voltage dividing module 102 cannot exceed the limit input voltage of the sampling end of the single-chip microcomputer 1011, nor can it be lower than the high-level threshold of the sampling end of the single-chip microcomputer 1011, so as to prevent the single-chip microcomputer 1011 from identifying the short-circuit fault of the circuit, and thus the safety and reliability of the operation of the single-chip microcomputer 1011 can be effectively protected.

[0087] The anode of the voltage stabilizing diode 1051 is also connected with one end of the third resistor 1052, and the other end of the third resistor 1052 is used for grounding.

[0088] Optionally, the anode of the voltage stabilizing diode 1051 is also connected with one end of a third resistor 1052, and the other end of the third resistor 1052 is grounded, the third resistor 1052 is used to provide a current for the voltage stabilizing diode 1051, the current provided by the third resistor 1052 for the voltage stabilizing diode 1051 needs to be greater than the minimum working current of the voltage stabilizing diode 1051, so as to ensure the voltage stabilizing effect of the voltage stabilizing diode 1051, and the current provided by the third resistor 1052 for the voltage stabilizing diode 1051 also needs to be less than the maximum working current of the voltage stabilizing diode 1051, so as to ensure the safe and stable operation of the voltage stabilizing diode 1051. Conversely, if the current provided by the third resistor 1052 for the voltage stabilizing diode 1051 is less than the minimum working current of the voltage stabilizing diode 1051, the voltage stabilizing effect of the voltage stabilizing diode 1051 is poor; if the current provided by the third resistor 1052 for the voltage stabilizing diode 1051 is greater than the maximum working current of the voltage stabilizing diode 1051, the voltage stabilizing diode 1051 will be damaged.

[0089] In an optional embodiment, referring to Figure 8 The short-circuit protection circuit provided by the embodiment of the present application further comprises a protection module 106.

[0090] The input end of the protection module 106 is connected with the first end of the switch module 103 and one end of the sampling resistor 104 respectively, and the output end of the protection module 106 is connected with the cathode of the voltage stabilizing diode 1051.

[0091] Optionally, the input end of the protection module 106 is connected with the first end of the switch module 103 and one end of the sampling resistor 104 respectively, and the output end of the protection module 106 is connected with the cathode of the voltage stabilizing diode 1051, and the protection module 106 can effectively prevent the influence of unstable operation of the switch module 103 or voltage mutation of the sampling resistor 104 on the voltage stabilizing module 105 and the voltage dividing module 102 in the subsequent circuit.

[0092] In the short-circuit protection circuit provided by the embodiment of the present application, the protection module 106 can be implemented by a diode 1061.

[0093] The input end of the diode 1061 is connected with the first end of the switch module 103 and one end of the sampling resistor 104 respectively, and the output end of the diode 1061 is connected with the cathode of the voltage stabilizing diode 1051.

[0094] Optionally, the input end of the diode 1061 is connected with the second end of the switch module 103 and one end of the sampling resistor 104 respectively, and the output end of the diode 1061 is connected with the cathode of the voltage stabilizing diode 1051, and the diode 1061 can further protect the stability of the operation of the single-chip microcomputer 1011, and can effectively prevent the interference and damage of the instability of the previous circuit on the single-chip microcomputer 1011.

[0095] In an optional implementation, referring to Figure 9 The short-circuit protection circuit provided by the embodiment of the present application further includes a filtering module 107.

[0096] One end of the filtering module 107 is connected with one end of the first resistor 1021 and one end of the second resistor 1022 respectively, and the other end of the filtering module 107 is grounded.

[0097] Optionally, one end of the filtering module 107 is connected with one end of the first resistor 1021 and one end of the second resistor 1022 respectively, that is, the filtering module 107 is connected inside the voltage dividing module 102, and the filtering module 107 is used to filter out the noise in the voltage signal in the voltage dividing module 102, so that the voltage signal output by the voltage dividing module 102 is more stable.

[0098] In the short-circuit protection circuit provided by the embodiment of the present application, the filtering module 107 is implemented by a capacitor 1071.

[0099] Optionally, the capacitor 1071 can be implemented by a small-capacity patch ceramic capacitor, and the present application does not limit the specific capacitance of the capacitor 1071.

[0100] One end of the capacitor 1071 is connected with one end of the first resistor 1021 and one end of the second resistor 1022 respectively, and the other end of the capacitor 1071 is grounded.

[0101] Optionally, one end of the capacitor 1071 is connected with one end of the second resistor 1022, and the other end of the capacitor 1071 is grounded, that is, the capacitor 1071 is connected in parallel with the second resistor 1022 in the voltage dividing module 102, and the capacitor 1071 can effectively filter out the noise of the voltage signal received by the voltage dividing module 102, so that the voltage signal sampled by the sampling end of the single-chip microcomputer 1011 is more stable and has less noise, thereby improving the accuracy of the signal detected by the short-circuit protection circuit.

[0102] In an optional implementation, referring to Figure 10The specific connection mode of the short-circuit protection circuit provided in the embodiment of the application is as follows: the output end of the single-chip microcomputer 1011 is connected with the gate of the metal oxide semiconductor field effect transistor 1031, the source of the metal oxide semiconductor field effect transistor 1031 is respectively connected with the input end of the diode 1061 and one end of the sampling resistor 104, the output end of the diode 1061 is connected with the cathode of the voltage stabilizing diode 1051, the anode of the voltage stabilizing diode 1051 is respectively connected with the other end of the third resistor 1052 and the other end of the first resistor 1021, one end of the first resistor 1021 is respectively connected with one end of the second resistor 1022, one end of the capacitor 1071 and the sampling end of the single-chip microcomputer 1011, the grounding end of the single-chip microcomputer 1011, the other end of the second resistor 1022, the other end of the capacitor 1071, the other end of the third resistor 1052 and the other end of the sampling resistor 104 are all grounded, and the single-chip microcomputer 1011 controls the on-off of the metal oxide semiconductor field effect transistor 1031 based on the voltage signal sampled by the sampling end, so as to realize the short-circuit protection function of the circuit.

[0103] In an alternative embodiment, Figure 11 and Figure 12 The simulation waveform diagram of the short-circuit protection circuit provided in the application is shown in Figure 11 and Figure 12 The short-circuit protection circuit provided in the embodiment of the application has high detection precision for the short-circuit signal, and the short-circuit protection circuit cuts off the power supply to protect the circuit from short circuit, so that the short-circuit protection function of the circuit can be quickly realized.

[0104] The above merely provides the specific implementation of the application, but the protection scope of the application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

[0105] The above merely provides the specific implementation of the application, but the protection scope of the application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims. The above merely provides the specific implementation of the application, but the protection scope of the application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A short-circuit protection circuit, characterized by comprising: The short-circuit protection circuit comprises a control module, a voltage division module, a switch module and a sampling resistor; an output end of the control module is connected with a control end of the switch module, a sampling end of the control module is connected with a first end of the voltage division module, a second end of the voltage division module is connected with one end of the sampling resistor, one end of the sampling resistor is also connected with a first end of the switch module, and a second end of the switch module is used for connecting a load; the other end of the sampling resistor, a third end of the voltage division module and a grounding end of the control module are all grounded, and the control module controls on-off of the switch module based on a voltage signal sampled by the sampling end.

2. The short circuit protection circuit according to claim 1, characterized in that The control module comprises a single-chip microcomputer. an output end of the single-chip microcomputer is connected with a control end of the switch module, and a sampling end of the single-chip microcomputer is connected with a first end of the voltage division module. a grounding end of the single-chip microcomputer, a third end of the voltage division module and the other end of the sampling resistor are all grounded.

3. The short circuit protection circuit of claim 2, wherein The switch module comprises a metal oxide semiconductor field effect transistor. a gate of the metal oxide semiconductor field effect transistor is connected with an output end of the single-chip microcomputer, a source of the metal oxide semiconductor field effect transistor is connected with one end of the sampling resistor and a second end of the voltage division module, and a drain of the metal oxide semiconductor field effect transistor is used for connecting a load.

4. The short circuit protection circuit of claim 3, wherein The voltage division module comprises a first resistor and a second resistor. one end of the first resistor and one end of the second resistor are both connected with a sampling end of the single-chip microcomputer, the other end of the first resistor is connected with a source of the metal oxide semiconductor field effect transistor and one end of the sampling resistor respectively, and the other end of the second resistor is grounded.

5. The short circuit protection circuit of claim 1, wherein The short-circuit protection circuit further comprises a voltage stabilizing module. a first end of the voltage stabilizing module is connected with a second end of the voltage division module, one end of the sampling resistor is connected with a second end of the voltage stabilizing module, and a third end of the voltage stabilizing module is grounded.

6. The short circuit protection circuit of claim 5, wherein The voltage stabilizing module comprises a voltage stabilizing diode and a third resistor. an anode of the voltage stabilizing diode is connected with a second end of the voltage division module, a cathode of the voltage stabilizing diode is connected with a first end of the switch module and one end of the sampling resistor respectively; the anode of the voltage stabilizing diode is also connected with one end of the third resistor, and the other end of the third resistor is used for grounding.

7. The short circuit protection circuit of claim 6, wherein The short-circuit protection circuit further comprises a protection module. input ends of the protection module are connected with a first end of the switch module and one end of the sampling resistor respectively, and an output end of the protection module is connected with a cathode of the voltage stabilizing diode.

8. The short circuit protection circuit of claim 7, wherein The protection module comprises a diode. input ends of the diode are connected with a first end of the switch module and one end of the sampling resistor respectively, and an output end of the diode is connected with a cathode of the voltage stabilizing diode.

9. The short circuit protection circuit of claim 4, wherein, The short-circuit protection circuit further comprises a filter module. one end of the filter module is connected with one end of the first resistor and one end of the second resistor respectively, and the other end of the filter module is grounded.

10. The short circuit protection circuit of claim 9, wherein The filter module comprises a capacitor. One end of the capacitor is connected with one end of the first resistor and one end of the second resistor respectively, and the other end of the capacitor is grounded.

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