Over-current detection circuit and electronic product

Abstract

The utility model discloses an overcurrent detection circuit and an electronic product. The over-current detection circuit comprises a controller, a first switch branch, a sampling branch, a clamping branch and a second switch branch. The first switch branch is turned on in response to a first control signal to generate a current flowing through a load, the current is input to the sampling branch, and the first switch branch is turned off in response to a second control signal to stop generating the current. The sampling branch generates a sampling voltage based on the current. The clamping branch clamps the voltage of the first node to a first voltage based on the sampling voltage. The first voltage and the sampling voltage are in a positive correlation relationship. The second switch branch outputs a first detection signal when the first voltage is smaller than the preset voltage, and outputs a second detection signal when the first voltage is larger than or equal to the preset voltage. The controller outputs a first control signal in response to the first detection signal and outputs a second control signal in response to the second detection signal. By means of the mode, the overcurrent protection function can be achieved with low cost.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and particularly to an overcurrent detection circuit and an electronic product. Background Art

[0002] During the use of an electronic product, when the current is too large, that is, an overcurrent anomaly occurs, it may cause damage to the electronic product. Therefore, in an electronic product, a circuit for detecting current is usually required to take corresponding protection measures in a timely manner when an overcurrent occurs.

[0003] Currently, a combination of an operational amplifier and a comparator is usually used to detect current changes. Specifically, after the current signal is amplified, it is compared with a set threshold by a comparator. When the set threshold is reached, the comparator outputs a corresponding level signal to the controller so that the controller stops the operation of the electronic product, thereby protecting the electronic product. However, the method using an operational amplifier and a comparator has a high cost. Summary of the Utility Model

[0004] The present application aims to provide an overcurrent detection circuit and an electronic product that can achieve the overcurrent protection function at a relatively low cost.

[0005] To achieve the above object, in a first aspect, the present application provides an overcurrent detection circuit, including:

[0006] A first switch branch, a sampling branch and a controller. The first switch branch is respectively connected to the controller, the sampling branch and the load. The first switch branch is configured to conduct in response to a first control signal output by the controller to generate a current flowing through the load, and the current is input to the sampling branch, and is configured to turn off in response to a second control signal output by the controller to stop generating the current;

[0007] The sampling branch is configured to generate a sampling voltage based on the current, wherein the sampling voltage has a positive correlation with the current;

[0008] A clamping branch and a second switch branch. The clamping branch is connected to the sampling branch, and the clamping branch and the second switch branch are connected at a first node. The clamping branch is configured to clamp the voltage of the first node to a first voltage based on the sampling voltage, wherein the first voltage has a positive correlation with the sampling voltage;

[0009] The second switch branch is also connected to the controller. The second switch branch is configured to output a first detection signal to the controller when the first voltage is less than a preset voltage, and is configured to output a second detection signal to the controller when the first voltage is greater than or equal to the preset voltage;

[0010] The controller is configured to output the first control signal in response to the first detection signal and to output the second control signal in response to the second detection signal.

[0011] In an alternative embodiment, the overcurrent detection circuit further includes a signal processing branch;

[0012] The signal processing branch is connected between the sampling branch and the controller, and is configured to input the sampled voltage to the controller after current limiting, pulling up and filtering, so that the controller determines the magnitude of the current.

[0013] In an alternative embodiment, the first switch branch includes a first resistor, a second resistor, a third resistor and a first switching transistor;

[0014] A first end of the first resistor is connected to the controller, a second end of the first resistor is respectively connected to a first end of the second resistor and a first end of the third resistor, a second end of the second resistor is grounded, a second end of the third resistor is connected to a first end of the first switching transistor, a second end of the first switching transistor is connected to the sampling branch, and a third end of the first switching transistor is connected to the load.

[0015] In an alternative embodiment, the sampling branch includes a fourth resistor;

[0016] A first end of the fourth resistor is connected to the first switch branch, and a second end of the fourth resistor is grounded.

[0017] In an alternative embodiment, the clamping branch includes a first diode;

[0018] An anode of the first diode is connected to the first node, and a cathode of the first diode is connected to the sampling branch.

[0019] In an alternative embodiment, the second switch branch includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a second switching transistor;

[0020] The fifth resistor, the sixth resistor and the seventh resistor are sequentially connected in series between a first power supply and ground, a connection point between the fifth resistor and the sixth resistor is the first node, a connection point between the sixth resistor and the seventh resistor is connected to a first end of the second switching transistor, a second end of the second switching transistor is grounded, a third end of the second switching transistor is respectively connected to the controller and a first end of the eighth resistor, and a second end of the eighth resistor is connected to the first power supply.

[0021] In an alternative embodiment, the signal processing branch includes a ninth resistor, a tenth resistor and a first capacitor;

[0022] The first end of the ninth resistor is connected to the sampling branch, and the second end of the ninth resistor is respectively connected to the first end of the tenth resistor, the first end of the first capacitor and the controller. The second end of the tenth resistor is connected to the first power supply, and the second end of the first capacitor is grounded.

[0023] In a second aspect, the present application provides an electronic product, including a load and the overcurrent detection circuit as described above;

[0024] The overcurrent detection circuit is connected to the load, and the overcurrent detection circuit is used to detect whether the current flowing through the load is overcurrent.

[0025] In an optional manner, the load includes a DC motor, and the electronic product further includes a second diode;

[0026] The overcurrent detection circuit is respectively connected to the negative electrode of the DC motor and the anode of the second diode, and the positive electrode of the DC motor is connected to the cathode of the second diode.

[0027] In an optional manner, the electronic product further includes a battery. The positive electrode of the battery is respectively connected to the positive electrode of the DC motor and the cathode of the second diode, and the negative electrode of the battery is grounded.

[0028] The beneficial effects of the present application are as follows: The overcurrent detection circuit provided by the present application includes a controller, a first switch branch, a sampling branch, a clamping branch, and a second switch branch. When no overcurrent anomaly occurs, the controller outputs a first control signal to the first switch branch to turn on the first switch branch. At this time, a current loop is formed to generate a current flowing through the load. Meanwhile, the current is input from the first switch branch to the sampling branch to generate a sampling voltage. Since the current and the sampling voltage are positively correlated, and the first voltage is also positively correlated with the sampling voltage, the first voltage and the current are positively correlated. Therefore, the first voltage corresponding to the current at this time is also less than the preset voltage, enabling the second switch branch to output a first detection signal to the controller. The controller maintains the output of the first control signal to keep the first switch branch turned on and keep generating the current. When an overcurrent anomaly occurs, based on the positive correlation between the first voltage and the current, it can be obtained that the first voltage corresponding to the current at this time increases to be greater than or equal to the preset voltage, enabling the second switch branch to output a second detection signal to the controller. After receiving the second detection signal, the controller outputs a second control signal to the first switch branch to turn off the first switch branch. At this time, the current loop is disconnected and no current is generated anymore, thus realizing the overcurrent protection function. Moreover, the present application only needs to use conventional devices such as resistors and switches, and the costs of devices such as resistors and switches are lower than those of operational amplifiers and comparators. It can be seen that, compared with the related art that needs to use operational amplifiers and comparators, the cost of the present application is lower, that is, the overcurrent protection function is realized at a lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] One or more embodiments are illustrated by way of example in the accompanying drawings, which illustrations do not constitute a limitation to the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the figures in the drawings do not constitute a proportional limitation.

[0030] Figure 1 FIG. is a schematic structural diagram of the overcurrent detection circuit provided in the first embodiment of the present application;

[0031] Figure 2 FIG. is a schematic structural diagram of the overcurrent detection circuit provided in the second embodiment of the present application;

[0032] Figure 3 FIG. is a schematic circuit diagram of the overcurrent detection circuit provided in the first embodiment of the present application;

[0033] Figure 4 FIG. is a schematic structural diagram of the electronic product provided in the first embodiment of the present application;

[0034] Figure 5 FIG. is a schematic circuit diagram of the electronic product provided in the first embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without making creative efforts fall within the scope of protection of this application.

[0036] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the overcurrent detection circuit provided in the embodiment of this application. As Figure 1 shown, the overcurrent detection circuit 100 includes a first switch branch 10, a sampling branch 20, a controller 30, a clamping branch 40, and a second switch branch 50.

[0037] Among them, the first switch branch 10 is respectively connected to the controller 30, the sampling branch 20, and the load 200. The clamping branch 40 is connected to the sampling branch 20. And the clamping branch 40 and the second switch branch 50 are connected at a first node P1. The second switch branch 50 is also connected to the controller 30.

[0038] Specifically, the first switch branch 10 is used to conduct in response to the first control signal output by the controller 30 to generate a current flowing through the load 200 and input the current to the sampling branch 20. The first switch branch 10 is also used to turn off in response to the second control signal output by the controller 30 to stop generating the current. The sampling branch 20 is used to generate a sampling voltage based on the current, where the sampling voltage has a positive correlation with the current. The clamping branch 40 is used to clamp the voltage of the first node P1 to a first voltage based on the sampling voltage, where the first voltage has a positive correlation with the sampling voltage. The second switch branch 50 is used to output a first detection signal to the controller 30 when the first voltage is less than a preset voltage, and is used to output a second detection signal to the controller 30 when the first voltage is greater than or equal to the preset voltage. The controller 30 is used to output a first control signal in response to the first detection signal and is used to output a second control signal in response to the second detection signal.

[0039] Among them, in some embodiments, the first control signal, the second control signal, the first detection signal, and the second detection signal are all level signals.

[0040] The positive correlation between the sampled voltage and the current means that the sampled voltage increases as the current increases and decreases as the current decreases. The positive correlation between the first voltage and the sampled voltage means that the first voltage increases as the sampled voltage increases and decreases as the sampled voltage decreases. Combining the two, it can be obtained that the first voltage and the current are positively correlated, that is, the first voltage increases as the current increases and decreases as the current decreases.

[0041] The preset voltage is a preset voltage value, which can be set based on the actual application scenario. This application embodiment does not make specific limitations on this, as long as it satisfies that when the current flowing through the load is greater than or equal to the preset current, the corresponding first voltage is greater than or equal to the preset voltage. Among them, when the current flowing through the load is greater than or equal to the preset current, it is determined that an overcurrent abnormality has occurred. In short, it is only necessary to configure that when the first voltage is greater than or equal to the preset voltage, an overcurrent abnormality occurs.

[0042] In practical applications, when no overcurrent abnormality occurs, the load 200 needs to operate normally. The controller 30 outputs a first control signal to the first switch branch 10 to make the first switch branch 10 conduct. At this time, a current loop is formed, and this current loop is the loop of the power supply that supplies power to the load 200 and the load, and this loop is formed corresponding to a closed loop. At this time, a current flowing through the load 200 is generated. At the same time, the current is input to the sampling branch 20 through the first switch branch 10, and a sampled voltage is generated on the sampling branch 20. Then, the clamping branch 40 clamps the voltage of the first node P1 to the first voltage based on the sampled voltage. Since the current and the first voltage are positively correlated, it can be determined at this time that based on the non-overcurrent of the current, the corresponding first voltage is also less than the preset voltage. Subsequently, the second switch branch 50 outputs a first detection signal to the controller 30. The controller 30 keeps outputting the first control signal to keep the first switch branch 10 conducting and keep generating the current flowing through the load 200. The load 200 can operate normally.

[0043] When an overcurrent abnormality occurs, the load 200 needs to stop operating. At this time, since the current and the first voltage are positively correlated, based on the occurrence of overcurrent, the corresponding first voltage also increases to be greater than or equal to the preset voltage. Subsequently, the second switch branch 50 outputs a second detection signal to the controller 30. After receiving the second detection signal, the controller 30 outputs a second control signal to the first switch branch 10 to make the first switch branch 10 turn off. At this time, the current loop is disconnected, that is, the loop where the load 200 and the power supply that supplies power to it are located is disconnected, and at this time, no current flowing through the load 200 is generated anymore, and the load 200 stops operating, thus realizing the overcurrent protection function.

[0044] In summary, to implement the above solution, the present application only needs to use conventional devices such as resistors and switches, and the cost of devices such as resistors and switches (the cost of a single device in this part of the devices is usually between a few cents and a few dimes) is lower than that of operational amplifiers and comparators (the cost of this part of the devices is usually between a few yuan and more than a dozen yuan). It can be seen that compared with the related art that needs to use operational amplifiers and comparators, the cost of the present application is lower, that is, the overcurrent protection function is realized at a lower cost.

[0045] In one embodiment, as Figure 2 shown, the overcurrent detection circuit 100 further includes a signal processing branch 60.

[0046] Among them, the signal processing branch 60 is connected between the sampling branch 20 and the controller 30. The signal processing branch 60 is used to limit the current, pull up and filter the sampling voltage and then input it to the controller 30, so that the controller 30 can determine the magnitude of the current.

[0047] Specifically, current limiting can prevent the current input to the controller 30 from being too large and damaging the controller 30. Pulling up can improve the anti-interference ability of the sampling voltage to improve its stability. Filtering can filter out spike pulses to protect the controller 30.

[0048] Please refer to Figure 3 , Figure 3 which exemplarily shows a circuit corresponding to the structure shown in Figure 2 .

[0049] In one embodiment, as Figure 3 shown, the first switch branch 10 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first switch tube Q1.

[0050] Among them, the first end of the first resistor R1 is connected to the controller 30, the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the first end of the third resistor R3, the second end of the second resistor R2 is grounded to GND, the second end of the third resistor R3 is connected to the first end of the first switch tube Q1, the second end of the first switch tube Q1 is connected to the sampling branch 20, and the third end of the first switch tube Q1 is connected to the load 200.

[0051] Specifically, the first resistor R1 and the second resistor R2 are voltage dividing resistors to divide the first control signal or the second control signal output by the controller 30 and then input it to the first end of the first switch tube Q1. Among them, in this embodiment, the first control signal is taken as a high-level signal and the second control signal is taken as a low-level signal as an example. The third resistor R3 is a current limiting resistor.

[0052] Wherein, in this embodiment, taking the first switching transistor Q1 as an NMOS transistor as an example. The gate of the NMOS transistor is the first end of the first switching transistor Q1, the source of the NMOS transistor is the second end of the first switching transistor Q1, and the drain of the NMOS transistor is the third end of the first switching transistor Q1.

[0053] In addition, the first switching transistor Q1 can be any controllable switch, for example, an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0054] In one embodiment, the sampling branch 20 includes a fourth resistor R4.

[0055] Wherein, the first end of the fourth resistor R4 is connected to the first switching branch 10, and the second end of the fourth resistor R4 is grounded to GND.

[0056] Specifically, when the first switching transistor Q1 is turned on, the current flowing through the load 200 also flows through the fourth resistor R4 to generate a sampling voltage across the two ends of the fourth resistor R4.

[0057] In one embodiment, the clamping branch 40 includes a first diode D1.

[0058] Wherein, the anode of the first diode D1 is connected to the first node P1, and the cathode of the first diode D1 is connected to the sampling branch 20, that is, the cathode of the first diode D1 is connected to the first end of the fourth resistor R4.

[0059] Specifically, the voltage VP1 of the first node P1 is the sum of the forward conduction voltage drop of the first diode D1 (denoted as VD1) and the voltage drop across the fourth resistor R4 (i.e., the first voltage V1), that is, VP1 = VD1 + V1. When the current flowing through the load 200 increases, V1 increases, and since VD1 remains unchanged, VP1 also increases accordingly. Until an overcurrent occurs, the current flowing through the load 200 experiences an overcurrent, thereby causing VP1 to increase to be greater than or equal to the preset voltage.

[0060] In one embodiment, the second switching branch 50 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a second switching transistor Q2.

[0061] Among them, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7 are sequentially connected in series between a first power supply V1 and a ground GND. A connection point between the fifth resistor R5 and the sixth resistor R6 is a first node P1. A connection point (denoted as a second node P2) between the sixth resistor R6 and the seventh resistor R7 is connected to a first end of a second switching transistor Q2. A second end of the second switching transistor Q2 is grounded to the GND. A third end of the second switching transistor Q2 is respectively connected to a controller 30 and a first end of an eighth resistor R8. A second end of the eighth resistor R8 is connected to the first power supply V1.

[0062] Specifically, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 are used for voltage division and current limiting. The eighth resistor R8 is used for pull-up.

[0063] When a voltage VP1 at the first node P1 is greater than or equal to a preset voltage, a voltage at the second node P2 is greater than a conduction voltage drop of the second switching transistor Q2, so that the second switching transistor Q2 is turned on. At this time, the third end of the second switching transistor Q2 is grounded to the GND to output a low-level signal (i.e., a second detection signal) to the controller 30. When the voltage VP1 at the first node P1 is less than the preset voltage, the voltage at the second node P2 is less than the conduction voltage drop of the second switching transistor Q2, and the second switching transistor Q2 remains off. At this time, the third end of the second switching transistor Q2 is connected to the first power supply V1 through the eighth resistor R8 to output a high-level signal (i.e., a first detection signal) to the controller 30.

[0064] Among them, in this embodiment, the second switching transistor Q2 is taken as a PNP-type triode as an example. The base of the PNP-type triode is the first end of the second switching transistor Q2. The emitter of the PNP-type triode is the second end of the second switching transistor Q2. The collector of the PNP-type triode is the third end of the second switching transistor Q2.

[0065] In addition, the second switching transistor Q2 can be any controllable switch, for example, an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0066] In one embodiment, the signal processing branch 60 includes a ninth resistor R9, a tenth resistor R10, and a first capacitor C1.

[0067] Among them, a first end of the ninth resistor R9 is connected to the sampling branch 20. A second end of the ninth resistor R9 is respectively connected to a first end of the tenth resistor R10, a first end of the first capacitor C1, and the controller 30. A second end of the tenth resistor R10 is connected to the first power supply V1. A second end of the first capacitor C1 is grounded to the GND.

[0068] Specifically, the ninth resistor R9 is a current-limiting resistor. The tenth resistor R10 is a pull-up resistor. The first capacitor C1 is a filtering capacitor.

[0069] The principle of the circuit shown below Figure 3 will be described again.

[0070] When no overcurrent anomaly occurs, the load 200 needs to operate normally. The controller 30 outputs a first control signal (i.e., a high-level signal) to the first switching transistor Q1 to turn on the first switching transistor Q1. At this time, the loop for supplying power to the load 200 is a closed loop, and a current flowing through the load 200 is generated. Meanwhile, the current is input to the fourth resistor R4 through the first switching transistor Q1, and a sampling voltage is generated across the fourth resistor R4. Then, the sum of the forward conduction voltage drop of the first diode D1 and the sampling voltage clamps the voltage of the first node P1 to a first voltage. Since the current and the first voltage are positively correlated, it can be determined that the first voltage corresponding to the current is also less than the preset voltage based on the fact that the current is not overcurrent at this time. Subsequently, the voltage of the second node P2 is less than the conduction voltage drop of the second switching transistor Q2, causing the second switching transistor Q2 to remain off. Based on the first power supply V1, a first detection signal (i.e., a high-level signal) is output to the controller 30. The controller 30 keeps outputting a high-level signal to the first end of the first switching transistor Q1 to keep the first switching transistor Q1 turned on and keep generating the current flowing through the load 200. The load 200 can operate normally.

[0071] When an overcurrent anomaly occurs, the load 200 needs to stop operating. At this time, since the current and the first voltage are positively correlated, based on the fact that overcurrent has occurred, the first voltage corresponding to the current also increases to be greater than or equal to the preset voltage. Subsequently, the voltage of the second node P2 is greater than the conduction voltage drop of the second switching transistor Q2, causing the second switching transistor Q2 to turn on. Based on the ground GND, a second detection signal (i.e., a low-level signal) is output to the controller 30. After receiving the second detection signal, the controller 30 outputs a second control signal (i.e., a low-level signal) to the first switching transistor Q1 to turn off the first switching transistor Q1. At this time, the loop for supplying power to the load 200 is disconnected, and no current flowing through the load 200 is generated anymore, and the load 200 stops operating, thus realizing the overcurrent protection function.

[0072] In summary, to implement the above solution in this application, only conventional components such as resistors (such as the first resistor R1 - the tenth resistor R10) and switches (such as the first switching transistor Q1 and the second switching transistor Q2) are required. The cost of components such as resistors and switches (the cost of a single component in this part is usually between a few cents and a few dimes) is lower than that of operational amplifiers and comparators (the cost of a single component in this part is usually between a few yuan and a dozen yuan). It can be seen that compared with the related art that requires the use of operational amplifiers and comparators, the cost of this application is lower, that is, the overcurrent protection function is realized at a lower cost.

[0073] Please refer to Figure 4 , Figure 4 , which is a schematic structural diagram of the electronic product provided by the embodiment of the present application. As Figure 4 shown, the electronic product 1000 includes a load 200 and an overcurrent detection circuit 100 in any embodiment of the present application.

[0074] Among them, the overcurrent detection circuit 100 is connected to the load 200. The overcurrent detection circuit 100 is used to detect whether the current flowing through the load 200 is overcurrent.

[0075] Figure 5 An exemplary circuit structure of the electronic product is shown. As Figure 5 shown, the load 200 includes a DC motor M1, and the electronic product 1000 further includes a second diode D2.

[0076] Among them, the overcurrent detection circuit 100 is respectively connected to the negative electrode of the DC motor M1 and the anode of the second diode D2, and the positive electrode of the DC motor M1 is connected to the cathode of the second diode D2. Among them, the second diode D2 is a freewheeling diode.

[0077] Among them, when the DC motor M1 has a short circuit or is blocked, resulting in overcurrent of the current flowing through the DC motor M1, the overcurrent detection circuit 100 can implement an overcurrent protection function.

[0078] In one embodiment, the electronic product 1000 further includes a battery 300.

[0079] Among them, the positive electrode of the battery 300 is respectively connected to the positive electrode of the DC motor M1 and the cathode of the second diode D2, and the negative electrode of the battery 300 is grounded to GND.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above. For the sake of brevity, they are not provided in detail; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An overcurrent detection circuit, characterized in that, Comprising: A first switch branch, a sampling branch and a controller. The first switch branch is respectively connected to the controller, the sampling branch and a load. The first switch branch is configured to conduct in response to a first control signal output by the controller to generate a current flowing through the load, and the current is input to the sampling branch, and is configured to turn off in response to a second control signal output by the controller to stop generating the current; The sampling branch is configured to generate a sampling voltage based on the current, wherein the sampling voltage has a positive correlation with the current; A clamping branch and a second switch branch. The clamping branch is connected to the sampling branch, and the clamping branch and the second switch branch are connected at a first node. The clamping branch is configured to clamp the voltage of the first node to a first voltage based on the sampling voltage, wherein the first voltage has a positive correlation with the sampling voltage; The second switch branch is further connected to the controller. The second switch branch is configured to output a first detection signal to the controller when the first voltage is less than a preset voltage, and is configured to output a second detection signal to the controller when the first voltage is greater than or equal to the preset voltage; The controller is configured to output the first control signal in response to the first detection signal, and is configured to output the second control signal in response to the second detection signal.

2. The overcurrent detection circuit according to claim 1, wherein The overcurrent detection circuit further includes a signal processing branch; The signal processing branch is connected between the sampling branch and the controller. The signal processing branch is configured to limit the current, pull up and filter the sampling voltage and then input it to the controller, so that the controller determines the magnitude of the current.

3. The overcurrent detection circuit according to claim 1 or 2, characterized in that, The first switch branch includes a first resistor, a second resistor, a third resistor and a first switch tube; A first end of the first resistor is connected to the controller, a second end of the first resistor is respectively connected to a first end of the second resistor and a first end of the third resistor, a second end of the second resistor is grounded, a second end of the third resistor is connected to a first end of the first switch tube, a second end of the first switch tube is connected to the sampling branch, and a third end of the first switch tube is connected to the load.

4. The overcurrent detection circuit according to claim 1 or 2, characterized in that, The sampling branch includes a fourth resistor; A first end of the fourth resistor is connected to the first switch branch, and a second end of the fourth resistor is grounded.

5. The overcurrent detection circuit according to claim 1 or 2, wherein The clamping branch includes a first diode; An anode of the first diode is connected to the first node, and a cathode of the first diode is connected to the sampling branch.

6. The overcurrent detection circuit according to claim 1 or 2, characterized in that, The second switch branch includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a second switch tube; The fifth resistor, the sixth resistor, and the seventh resistor are connected in series between the first power supply and the ground in sequence. The connection point between the fifth resistor and the sixth resistor is the first node. The connection point between the sixth resistor and the seventh resistor is connected to the first end of the second switching transistor. The second end of the second switching transistor is grounded. The third end of the second switching transistor is connected to the controller and the first end of the eighth resistor respectively. The second end of the eighth resistor is connected to the first power supply.

7. The overcurrent detection circuit according to claim 2, wherein The signal processing branch includes a ninth resistor, a tenth resistor, and a first capacitor; The first end of the ninth resistor is connected to the sampling branch. The second end of the ninth resistor is connected to the first end of the tenth resistor, the first end of the first capacitor, and the controller respectively. The second end of the tenth resistor is connected to the first power supply. The second end of the first capacitor is grounded.

8. An electronic product, characterized in that, It includes a load and the overcurrent detection circuit according to any one of claims 1-7; The overcurrent detection circuit is connected to the load, and the overcurrent detection circuit is used to detect whether the current flowing through the load is overcurrent.

9. The electronic product according to claim 8, wherein, The load includes a DC motor, and the electronic product further includes a second diode; The overcurrent detection circuit is connected to the negative electrode of the DC motor and the anode of the second diode respectively. The positive electrode of the DC motor is connected to the cathode of the second diode.

10. The electronic product according to claim 9, characterized in that, The electronic product further includes a battery. The positive electrode of the battery is connected to the positive electrode of the DC motor and the cathode of the second diode respectively. The negative electrode of the battery is grounded.

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