Hardware self-locking protection circuit and power supply product

Abstract

The utility model relates to the technical field of lithium ion battery protection, and discloses a hardware self-locking protection circuit and a power supply product. The hardware self-locking protection circuit comprises a short circuit identification unit and a main loop switch cut-off unit. The short circuit identification unit comprises a resistor R1, a capacitor C46, a switch tube Q4 and a resistor R55; the main loop switch cut-off unit comprises a resistor R56, a switch tube Q6, a switch tube Q5 and a resistor R4; when the main loop of the power supply product is short-circuited, the switch tube Q4 is switched on, the positive terminal of the switch tube Q4 is pulled down to a low level, then the switch tube Q6 and the switch tube Q5 are switched on, at the moment, the control end of the main loop switch is pulled down to a low level, and the main loop switch is switched off. According to the utility model, the conduction characteristic of the switch tube is utilized to identify whether the main loop is short-circuited or not, and the main loop switch is cut off immediately when the short-circuit occurs so as to realize the short-circuit protection function, and the response is timely.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery protection technology, and in particular to a hardware self-locking protection circuit and power supply product. Background Technology

[0002] With the diversification of user needs, many power supply products are equipped with multiple output interfaces. However, many of the output terminals are exposed, which may pose a short circuit risk, especially when the cables are not protected. Short circuits can damage the power supply. Therefore, power supply products generally need to be equipped with short circuit protection circuits to ensure the safety of the power supply products.

[0003] Currently, short-circuit protection circuits in commercially available power supply products typically use voltage detection chips or dedicated operational amplifier modules to detect voltage / current in the circuit to identify short circuits. When a short circuit is detected, the BMS (Battery Management System) sends a control signal to disconnect the main circuit, thus protecting the power supply. This method requires the voltage detection chip or operational amplifier module to first detect the short circuit and send a control signal before disconnecting the circuit. There is a delay in circuit disconnection, and excessive short-circuit current may burn out some components in the circuit in a short time.

[0004] The above information is provided as background information only to aid in understanding this disclosure and does not constitute an assertion or admission that any of the above content can be used as prior art relative to this disclosure. Utility Model Content

[0005] The purpose of this utility model is to provide a hardware self-locking protection circuit and power supply product to solve or at least partially solve the technical problems existing in the prior art.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In the first aspect, this utility model provides a hardware self-locking protection circuit, including a short circuit identification unit and a main circuit switch cut-off unit;

[0008] The short-circuit identification unit includes a resistor R1, a capacitor C46, ​​a switch Q4, and a resistor R55. The first end of the resistor R1 is used to electrically connect to the negative terminal of the power supply product. The second end of the resistor R1 is electrically connected to the control terminal of the switch Q4 and the first end of the resistor R55. The second end of the resistor R55 is electrically connected to the negative terminal of the switch Q4. The capacitor C46 is connected in parallel across the two ends of the resistor R1. The negative terminal of the switch Q4 is electrically connected to the signal ground.

[0009] The main circuit switch disconnection unit includes a resistor R56, a switch Q6, a switch Q5, and a resistor R4. The first end of the resistor R56 is electrically connected to the positive terminal of the switch Q6, and the first end of the resistor R56 is used to electrically connect to the positive terminal of the power supply product. The second end of the resistor R56 is electrically connected to the positive terminal of the switch Q4 and the control terminal of the switch Q6. The negative terminal of the switch Q6 is electrically connected to the control terminal of the switch Q5. The control terminal of the switch Q5 is also electrically connected to the first end of the resistor R4. The second end of the resistor R4 and the negative terminal of the switch Q5 are both electrically connected to signal ground. The positive terminal of the switch Q5 is used to electrically connect to the control terminal of the main circuit switch.

[0010] When a short circuit occurs in the main circuit of the power supply product, switch Q4 is turned on, and the positive terminal of switch Q4 is pulled low to a low level, which in turn turns on switch Q6 and switch Q5. At this time, the control terminal of the main circuit switch is pulled low to a low level, and the main circuit switch is turned off.

[0011] Optionally, the short-circuit identification unit further includes a switching transistor M5;

[0012] The positive terminal of switch transistor M5 is electrically connected to the negative terminal of switch transistor Q4, the negative terminal of switch transistor M5 is electrically connected to signal ground, and the control terminal of switch transistor M5 is electrically connected to the short-circuit protection function start / stop port of the power supply product.

[0013] When the short-circuit protection function start / stop port outputs a high-level signal, switch M5 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q4 is turned on.

[0014] Optionally, the main circuit switch disconnection unit further includes a switch Q7, a resistor R5, and a switch M1;

[0015] The negative terminal of switch Q6 is also electrically connected to the control terminal of switch Q7. The positive terminal of switch Q7 is electrically connected to the positive terminal of switch Q4. The control terminal of switch Q7 is also electrically connected to the first terminal of resistor R5. The second terminal of resistor R5 and the negative terminal of switch Q7 are both electrically connected to the positive terminal of switch M1. The negative terminal of switch M1 is electrically connected to signal ground. The control terminal of switch M1 is electrically connected to the short-circuit protection function start / stop port of the power supply product.

[0016] When the short-circuit protection function start / stop port outputs a high-level signal, switch M1 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q7 is turned on.

[0017] Optionally, the short-circuit identification unit further includes resistors R50, R53, and R54, and capacitor C47;

[0018] The first end of resistor R50 is used to electrically connect to the negative terminal of the power supply product, and the second end of resistor R50 is electrically connected to the first end of resistor R1; the first end of resistor R53 is electrically connected to the short-circuit protection function start / stop port of the power supply product, and the second end of resistor R53 is electrically connected to the control terminal of switch transistor M5, the first end of resistor R54 and the positive terminal of capacitor C47 respectively. The second end of resistor R54 and the negative terminal of capacitor C47 are both electrically connected to signal ground.

[0019] Optionally, the main circuit switch disconnection unit further includes resistor R3, resistor R6, and capacitor C1;

[0020] The first end of resistor R3 is electrically connected to the short-circuit protection start / stop port of the power supply product. The second end of resistor R3 is electrically connected to the first end of resistor R6, the positive terminal of capacitor C1, and the control terminal of switch M1. The second end of resistor R6 and the negative terminal of capacitor C1 are both electrically connected to signal ground.

[0021] Optionally, the main circuit switch disconnection unit further includes resistors R57, R2, R58, and R59;

[0022] The first end of resistor R57 is used to electrically connect to the positive terminal of the power supply product. The second end of resistor R57 is electrically connected to the first end of resistor R56 and the positive terminal of switch Q6. The first end of resistor R2 is electrically connected to the negative terminal of switch Q6 and the first end of resistor R58. The second end of resistor R2 is electrically connected to the control terminal of switch Q5. The first end of resistor R58 is electrically connected to the control terminal of switch Q7. The first end of resistor R59 is electrically connected to the positive terminal of switch Q4. The second end of resistor R59 is electrically connected to the positive terminal of switch Q7.

[0023] Optionally, switching transistors Q4, Q5, and Q7 are NPN transistors, and switching transistor Q6 is a PNP transistor;

[0024] Switch M5 and switch M1 are enhancement-mode NMOS transistors.

[0025] Secondly, this utility model provides a power supply product, including a main circuit switch, and a hardware self-locking protection circuit for controlling the on / off state of the main circuit switch, wherein the hardware self-locking protection circuit adopts a hardware self-locking protection circuit as described above.

[0026] Optionally, the power supply product is a DC power supply.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention adds a hardware self-locking protection circuit composed of several electronic components to the power supply product. It utilizes the conduction characteristics of the switching transistor to identify whether a short circuit has occurred in the main circuit, and immediately cuts off the main circuit switch when a short circuit occurs to achieve the short circuit protection function. The response is timely and can better protect the power supply product.

[0029] This invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of this invention. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a hardware self-locking protection circuit provided in an embodiment of this utility model. Detailed Implementation

[0032] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0033] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0034] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0035] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0036] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0037] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0038] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0039] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0040] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0041] Example 1:

[0042] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a hardware self-locking protection circuit provided in an embodiment of this utility model;

[0043] like Figure 1 As shown, this utility model provides a hardware self-locking protection circuit, including a short-circuit identification unit and a main circuit switch cut-off unit;

[0044] For ease of explanation, Figure 1 The left or top end of a central electronic component is referred to as the first end. Figure 1 The right or lower end of an electronic component is referred to as the second end;

[0045] Specifically, the short-circuit identification unit includes a resistor R1, a capacitor C46, ​​a switching transistor Q4, and a resistor R55; the first terminal of resistor R1 is used to electrically connect to the negative terminal of the power supply product. Figure 1 The DC-port in the circuit is connected to the control terminal of the switching transistor Q4 and the first terminal of the resistor R55. The second terminal of the resistor R55 is connected to the negative terminal of the switching transistor Q4. The capacitor C46 is connected in parallel across the two ends of the resistor R1. The negative terminal of the switching transistor Q4 is connected to the signal ground. Figure 1 (GND in the middle);

[0046] The main circuit switch disconnection unit includes a resistor R56, a switching transistor Q6, a switching transistor Q5, and a resistor R4; the first end of resistor R56 is electrically connected to the positive terminal of switching transistor Q6, and the first end of resistor R56 is used to electrically connect to the positive terminal of the power supply product. Figure 1 The DC+ port in the circuit is connected to the DC+ port. The second end of resistor R56 is electrically connected to the positive terminal of switch Q4 and the control terminal of switch Q6. The negative terminal of switch Q6 is electrically connected to the control terminal of switch Q5. The control terminal of switch Q5 is also electrically connected to the first end of resistor R4. The second end of resistor R4 and the negative terminal of switch Q5 are both electrically connected to signal ground. The positive terminal of switch Q5 is used to electrically connect to the control terminal of the main circuit switch. Figure 1(DC_EN port in the middle);

[0047] When a short circuit occurs in the main circuit of the power supply product, switch Q4 is turned on, and the positive terminal of switch Q4 is pulled low to a low level, which in turn turns on switch Q6 and switch Q5. At this time, the control terminal of the main circuit switch is pulled low to a low level, and the main circuit switch is turned off.

[0048] This embodiment adds a hardware self-locking protection circuit composed of several electronic components to the power supply product. It utilizes the conduction characteristics of the switching transistor to identify whether a short circuit has occurred in the main circuit, and immediately cuts off the main circuit switch when a short circuit occurs to achieve the short circuit protection function. The response is timely and can better protect the power supply product.

[0049] Furthermore, the short-circuit identification unit also includes a switching transistor M5;

[0050] The positive terminal of switch transistor M5 is electrically connected to the negative terminal of switch transistor Q4, the negative terminal of switch transistor M5 is electrically connected to signal ground, and the control terminal of switch transistor M5 is electrically connected to the short-circuit protection start / stop port of the power supply product. Figure 1 (DC_0V port in the middle);

[0051] When the short-circuit protection function start / stop port outputs a high-level signal, switch M5 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q4 is turned on.

[0052] This embodiment utilizes the functional interface on the power supply product to enable / disable the short-circuit protection function, making the short-circuit protection function more intelligent. Specifically, when the user needs to enable the short-circuit protection function, the DC_0V port outputs a high-level signal (for example, in this embodiment, the high-level signal of DC_0V is 3.3V); when the user does not need to enable or wants to disable the short-circuit protection function, the DC_0V port outputs a low-level signal.

[0053] Furthermore, the main circuit switch cutting-off unit also includes a switch Q7, a resistor R5, and a switch M1;

[0054] The negative terminal of switch Q6 is also electrically connected to the control terminal of switch Q7, and the positive terminal of switch Q7 is electrically connected to the positive terminal of switch Q4. Figure 1 The LOCK signal terminal of the switch transistor Q7 is connected to the first terminal of the resistor R5. The second terminal of the resistor R5 and the negative terminal of the switch transistor Q7 are both connected to the positive terminal of the switch transistor M1. The negative terminal of the switch transistor M1 is connected to the signal ground. The control terminal of the switch transistor M1 is connected to the short-circuit protection function start / stop port of the power supply product.

[0055] When the short-circuit protection function start / stop port outputs a high-level signal, switch M1 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q7 is turned on.

[0056] More specifically, the short-circuit identification unit also includes resistors R50, R53, and R54, and capacitor C47;

[0057] The first end of resistor R50 is used to electrically connect to the negative terminal of the power supply product, and the second end of resistor R50 is electrically connected to the first end of resistor R1; the first end of resistor R53 is electrically connected to the short-circuit protection function start / stop port of the power supply product, and the second end of resistor R53 is electrically connected to the control terminal of switch transistor M5, the first end of resistor R54 and the positive terminal of capacitor C47 respectively. The second end of resistor R54 and the negative terminal of capacitor C47 are both electrically connected to signal ground.

[0058] Optionally, the main circuit switch disconnection unit further includes resistor R3, resistor R6, and capacitor C1;

[0059] The first end of resistor R3 is electrically connected to the short-circuit protection start / stop port of the power supply product. The second end of resistor R3 is electrically connected to the first end of resistor R6, the positive terminal of capacitor C1, and the control terminal of switch M1. The second end of resistor R6 and the negative terminal of capacitor C1 are both electrically connected to signal ground.

[0060] Optionally, the main circuit switch disconnection unit further includes resistors R57, R2, R58, and R59;

[0061] The first end of resistor R57 is used to electrically connect to the positive terminal of the power supply product. The second end of resistor R57 is electrically connected to the first end of resistor R56 and the positive terminal of switch Q6. The first end of resistor R2 is electrically connected to the negative terminal of switch Q6 and the first end of resistor R58. The second end of resistor R2 is electrically connected to the control terminal of switch Q5. The first end of resistor R58 is electrically connected to the control terminal of switch Q7. The first end of resistor R59 is electrically connected to the positive terminal of switch Q4. The second end of resistor R59 is electrically connected to the positive terminal of switch Q7.

[0062] For example, in this embodiment, switch Q4, switch Q5 and switch Q7 are NPN transistors, and switch Q6 is a PNP transistor;

[0063] Switch M5 and switch M1 are enhancement-mode NMOS transistors.

[0064] It should be noted that the main circuit switch disconnection unit in this embodiment has a state self-locking function, that is:

[0065] The DC_0V port outputs a high-level signal, turning on switches M5 and M1. In the event of a short circuit, the DC- voltage rises rapidly and is applied to the base of switch Q4 through capacitor C46. Switches Q6, Q5, and Q7 then activate. At this time, the LOCK signal terminal is pulled low, keeping switch Q6 continuously on, simultaneously ensuring that switches Q5 and Q7 remain on, thus achieving self-locking control. When the short-circuit protection function start / stop port signal is pulled low, switch Q7 stops working and enters the cutoff state, the circuit's self-locking fails, and DC_EN disconnects, restoring normal operation.

[0066] Example 2:

[0067] This embodiment provides a power supply product, including a main circuit switch and a hardware self-locking protection circuit for controlling the on / off state of the main circuit switch. The hardware self-locking protection circuit adopts a hardware self-locking protection circuit as described in Embodiment 1.

[0068] In this embodiment, the power supply product is a DC power supply.

[0069] Since the hardware self-locking protection circuit has been described in detail in Embodiment 1, it will not be repeated in this embodiment.

[0070] In summary, to protect against direct short circuits in the power supply, this embodiment provides a protection circuit using a transistor for judgment and self-locking, suitable for DC power supply products. A switching circuit is added to the output circuit, utilizing the base conduction voltage of the transistor to identify whether the circuit is short-circuited and provide self-locking protection. When the output current is abnormal and a conduction voltage drop occurs at the transistor base, the output circuit is controlled and quickly shut off, and the control drive is pulled low by the transistor for self-locking. The hardware circuit has a fast response speed and higher stability.

[0071] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A hardware self-locking protection circuit, characterized in that, Includes a short-circuit identification unit and a main circuit switch disconnection unit; The short-circuit identification unit includes a resistor R1, a capacitor C46, ​​a switch Q4, and a resistor R55. The first end of the resistor R1 is used to electrically connect to the negative terminal of the power supply product. The second end of the resistor R1 is electrically connected to the control terminal of the switch Q4 and the first end of the resistor R55. The second end of the resistor R55 is electrically connected to the negative terminal of the switch Q4. The capacitor C46 is connected in parallel across the two ends of the resistor R1. The negative terminal of the switch Q4 is electrically connected to the signal ground. The main circuit switch disconnection unit includes a resistor R56, a switch Q6, a switch Q5, and a resistor R4. The first end of the resistor R56 is electrically connected to the positive terminal of the switch Q6, and the first end of the resistor R56 is used to electrically connect to the positive terminal of the power supply product. The second end of the resistor R56 is electrically connected to the positive terminal of the switch Q4 and the control terminal of the switch Q6. The negative terminal of the switch Q6 is electrically connected to the control terminal of the switch Q5. The control terminal of the switch Q5 is also electrically connected to the first end of the resistor R4. The second end of the resistor R4 and the negative terminal of the switch Q5 are both electrically connected to signal ground. The positive terminal of the switch Q5 is used to electrically connect to the control terminal of the main circuit switch. When a short circuit occurs in the main circuit of the power supply product, switch Q4 is turned on, and the positive terminal of switch Q4 is pulled low to a low level, which in turn turns on switch Q6 and switch Q5. At this time, the control terminal of the main circuit switch is pulled low to a low level, and the main circuit switch is turned off.

2. The hardware self-locking protection circuit according to claim 1, characterized in that, The short-circuit identification unit also includes a switching transistor M5; The positive terminal of switch transistor M5 is electrically connected to the negative terminal of switch transistor Q4, the negative terminal of switch transistor M5 is electrically connected to signal ground, and the control terminal of switch transistor M5 is electrically connected to the short-circuit protection function start / stop port of the power supply product. When the short-circuit protection function start / stop port outputs a high-level signal, switch M5 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q4 is turned on.

3. The hardware self-locking protection circuit according to claim 2, characterized in that, The main circuit switch disconnection unit also includes a switch Q7, a resistor R5 and a switch M1; The negative terminal of switch Q6 is also electrically connected to the control terminal of switch Q7. The positive terminal of switch Q7 is electrically connected to the positive terminal of switch Q4. The control terminal of switch Q7 is also electrically connected to the first terminal of resistor R5. The second terminal of resistor R5 and the negative terminal of switch Q7 are both electrically connected to the positive terminal of switch M1. The negative terminal of switch M1 is electrically connected to signal ground. The control terminal of switch M1 is electrically connected to the short-circuit protection function start / stop port of the power supply product. When the short-circuit protection function start / stop port outputs a high-level signal, switch M1 is turned on. At this time, if a short circuit occurs in the main circuit, switch Q7 is turned on.

4. A hardware self-locking protection circuit according to claim 3, characterized in that, The short-circuit identification unit also includes resistors R50, R53, and R54, and capacitor C47; The first end of resistor R50 is used to electrically connect to the negative terminal of the power supply product, and the second end of resistor R50 is electrically connected to the first end of resistor R1; the first end of resistor R53 is electrically connected to the short-circuit protection function start / stop port of the power supply product, and the second end of resistor R53 is electrically connected to the control terminal of switch transistor M5, the first end of resistor R54 and the positive terminal of capacitor C47 respectively. The second end of resistor R54 and the negative terminal of capacitor C47 are both electrically connected to signal ground.

5. A hardware self-locking protection circuit according to claim 4, characterized in that, The main circuit switch cut-off unit also includes resistor R3, resistor R6 and capacitor C1; The first end of resistor R3 is electrically connected to the short-circuit protection start / stop port of the power supply product. The second end of resistor R3 is electrically connected to the first end of resistor R6, the positive terminal of capacitor C1, and the control terminal of switch M1. The second end of resistor R6 and the negative terminal of capacitor C1 are both electrically connected to signal ground.

6. A hardware self-locking protection circuit according to claim 5, characterized in that, The main circuit switch disconnection unit also includes resistors R57, R2, R58, and R59; The first end of resistor R57 is used to electrically connect to the positive terminal of the power supply product. The second end of resistor R57 is electrically connected to the first end of resistor R56 and the positive terminal of switch Q6. The first end of resistor R2 is electrically connected to the negative terminal of switch Q6 and the first end of resistor R58. The second end of resistor R2 is electrically connected to the control terminal of switch Q5. The first end of resistor R58 is electrically connected to the control terminal of switch Q7. The first end of resistor R59 is electrically connected to the positive terminal of switch Q4. The second end of resistor R59 is electrically connected to the positive terminal of switch Q7.

7. A hardware self-locking protection circuit according to claim 6, characterized in that, Switching transistors Q4, Q5, and Q7 are NPN transistors, while switching transistor Q6 is a PNP transistor. Switch M5 and switch M1 are enhancement-mode NMOS transistors.

8. A power supply product, comprising a main circuit switch, characterized in that, It also includes a hardware self-locking protection circuit for controlling the on / off state of the main circuit switch, wherein the hardware self-locking protection circuit adopts a hardware self-locking protection circuit as described in any one of claims 1-7.

9. A power supply product according to claim 8, characterized in that, The power supply product is a DC power supply.

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