Protection circuit and vehicle

Abstract

The embodiment of the application provides a protection circuit and a vehicle, and belongs to the technical field of circuit safety, and comprises: an isolating switch module connected with an input port and an output port; a processor module connected with the isolating switch module, the processor module being used for outputting an enable signal, the enable signal being used for turning on the isolating switch module; a soft start protection module connected with the output port, the soft start protection module being used for outputting an execution signal; a first switch module connected with the soft start protection module and the processor module respectively, the first switch module being used for grounding a working power supply after being turned on based on the execution signal, and the processor module being further used for outputting an off signal based on the working power supply after grounding, so that the isolating switch module is disconnected. The protection circuit provided by the embodiment of the application is used for outputting the off signal by the processor module when an abnormality occurs in a current signal of the output port, controlling the isolating switch module, and thereby completely disconnecting the input port and the output port, so that the circuit is prevented from being damaged.

Description

Technical Field

[0001] This application relates to the field of circuit safety technology, and more particularly to a protection circuit and vehicle. Background Technology

[0002] The on-board charger (OBC) and DC / DC converter both draw power from a low-voltage battery. Typically, the battery voltage is stepped down to 5V by a buck circuit and then output through a push-pull isolation converter to provide multiple isolated regulated power supplies to meet the power supply voltage requirements of the OBC and the various circuits within the DC / DC converter. However, if a short circuit occurs in the output of the buck circuit or in any of its windings, the buck circuit may be damaged, or it may enter a hiccup protection mode, preventing the regulated power supply from providing normal output. Utility Model Content

[0003] This application provides a protection circuit and vehicle to solve the above-mentioned technical problems.

[0004] In a first aspect, embodiments of this application provide a protection circuit, including:

[0005] A disconnect switch module, wherein the disconnect switch module is connected to the input port and the output port of the protection circuit;

[0006] A processor module, which is connected to the disconnector module;

[0007] A soft-start protection module is connected to the output port;

[0008] The first switch module is connected to both the soft-start protection module and the processor module.

[0009] Secondly, embodiments of this application provide a vehicle, including: a battery, on-board electrical components, and a protection circuit as described in any one of the first aspects;

[0010] The battery is connected to the vehicle-mounted electrical components, and the protection circuit is connected between the battery and the vehicle-mounted electrical components.

[0011] One of the above technical solutions has the following advantages or beneficial effects:

[0012] This application provides a protection circuit, including: an isolating switch module connected to the input port and output port of the protection circuit; a processor module connected to the isolating switch module; a soft-start protection module connected to the output port; and a first switch module connected to both the soft-start protection module and the processor module. The protection circuit provided in this application includes an isolating switch module, a processor module, a soft-start protection module, and a first switch module. By setting an isolating switch module between the input port and the output port, this protection circuit can disconnect the connection between the input port and the output port when the output port is short-circuited, thereby preventing the buck circuit from entering a hiccup protection mode and protecting the components in the circuit. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0015] Figure 1 A schematic diagram of the module connection of the protection circuit provided in the embodiments of this application;

[0016] Figure 2 A circuit connection diagram of the soft-start protection module provided in an embodiment of this application;

[0017] Figure 3 This is a circuit connection diagram of a soft-start comparator provided in an embodiment of this application;

[0018] Figure 4 A circuit connection diagram of the first comparison and judgment module provided in an embodiment of this application;

[0019] Figure 5 A circuit connection diagram of the first comparison judgment module and the logic judgment module provided in the embodiments of this application;

[0020] Figure 6 A circuit connection diagram of the second switch module provided in an embodiment of this application;

[0021] Figure 7 A circuit connection diagram of the first switch module provided in an embodiment of this application;

[0022] Figure 8A circuit connection diagram of the isolating switch module and the processor module provided in an embodiment of this application;

[0023] Figure 9 This is a circuit connection diagram of the output execution module provided in an embodiment of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] In the embodiments of this application, "at least one" refers to one or more; "multiple" refers to two or more. In the description of this application, the terms "first," "second," "third," etc., are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0027] References such as “one embodiment” or “some embodiments” as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the terms “comprising,” “including,” “having,” and variations thereof, as used in this specification, mean “including, but not limited to,” unless otherwise specifically emphasized.

[0028] It should be noted that in the embodiments of this application, "and / or" describes the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after it are in an "or" relationship.

[0029] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0030] The specific implementation methods of this application are illustrated below through examples:

[0031] like Figure 1 As shown, this application embodiment provides a protection circuit, including: an isolating switch module configured to connect the input port and output port of the protection circuit; a processor module connected to the isolating switch module, configured to output an enable signal based on the input operating power supply, the enable signal being configured to turn on the isolating switch module to connect the input port and the output port; a soft-start protection module connected to the output port, configured to output an execution signal based on the current signal of the output port; and a first switch module connected to both the soft-start protection module and the processor module, configured to ground the operating power supply after the execution signal is turned on, and the processor module further configured to output a cutoff signal based on the grounded operating power supply, the cutoff signal being configured to disconnect the isolating switch module to protect the circuit.

[0032] Specifically, in this embodiment, the isolating switch module serves as a direct connection node between the input and output ports, and undertakes the physical task of circuit switching. During normal circuit operation, the isolating switch module is turned on to connect the input and output ports, ensuring power transmission. When the protection mechanism is triggered, the isolating switch module quickly disconnects, thereby completely cutting off the fault circuit and preventing abnormal current from continuously damaging the equipment.

[0033] In this embodiment, the processor module controls the on / off state of the isolating switch via an enable signal and indirectly triggers protection logic by monitoring the working power supply status (such as voltage drop or short circuit). During circuit power-on initialization: when the working power supply is connected, the processor module outputs a high-level enable signal, thereby controlling the isolating switch module to conduct and establishing a power path. When a circuit fault occurs, the first switch module grounds the working power supply, causing a sudden voltage drop. After detecting the abnormality, the processor module outputs a cutoff signal, thereby controlling the isolating switch module to disconnect.

[0034] In this embodiment, the soft-start protection module achieves a dual objective through current signal feedback: soft-start control and overcurrent protection. During the start-up phase, the soft-start protection module gradually increases the output current to prevent surge impact on the load. During the overcurrent protection phase, the soft-start protection module monitors the output port current in real time. When a short circuit occurs (or the current exceeds a threshold, such as 3-5 times the rated current), the module outputs an execution signal to trigger the protection process.

[0035] In this embodiment, the first switch module forcibly pulls the operating power supply of the input processor module low through a grounding path, thereby causing the processor module to output a corresponding cutoff signal. When the soft-start protection module detects an abnormal current, it outputs a high-level execution signal to control the first switch module to turn on. After the switch is turned on, the positive terminal of the operating power supply is pulled low to zero potential through the grounding path, causing the processor to lose power and stop outputting the enable signal, thereby controlling the isolating switch module to open.

[0036] It is understood that the protection circuit provided in this application embodiment includes an isolating switch module, a processor module, a soft-start protection module, and a first switch module. This protection circuit, by setting an isolating switch module between the input port and the output port, can disconnect the connection between the input port and the output port when the output port is short-circuited, thereby preventing the buck circuit from entering the hiccup protection mode and protecting the components in the circuit.

[0037] like Figure 2 As shown in the embodiment of this application, the soft-start protection module includes a soft-start protection unit, which includes a soft-start comparator. The soft-start comparator has a first comparison input terminal FB, a second comparison input terminal SS, and a first comparison output terminal COMP. The first comparison input terminal FB is connected to the output port and is configured to acquire the current signal of the output port. The second comparison input terminal SS is connected to an internal DC source and is grounded through a fourth capacitor C4. The second comparison input terminal SS is configured to output a first control signal based on the internal DC source. The first comparison output terminal COMP is configured to output a second control signal based on the level comparison result of the first comparison input terminal FB and the second comparison input terminal SS.

[0038] Specifically, the soft-start protection unit includes a first control chip U3 and peripheral circuitry. The soft-start comparator is integrated into the first control chip U3. In addition to the first comparator input terminal FB, the second comparator input terminal SS, and the first comparator output terminal COMP, the first control chip U3 also includes a power supply pin VCC, a current feedback pin CS, and a drive pin DR. The peripheral circuitry includes a fourth resistor R4, a sixth resistor R6, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a twelfth resistor R12, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. The power supply pin VCC is connected between the input and output ports via the fourth resistor R4; the data ready pin DR is connected to the output port via the sixth resistor R6; one end of the eighth resistor R8 is connected to the supply voltage VDD, and the other end of the eighth resistor R8 is connected to one end of the tenth resistor R10 and the first comparator input FB, respectively, and the other end of the tenth resistor R10 is grounded; the current feedback pin CS is connected to the output port via the ninth resistor R9, and the current feedback pin CS is also grounded via the third capacitor C3; the first comparator output COMP is connected to the twelfth resistor R12 and the fifth capacitor C5 in sequence, and the other end of the fifth capacitor C5 is grounded; the second comparator input SS is grounded via the fourth capacitor C4.

[0039] like Figure 3 As shown in this embodiment, the first comparison input terminal FB in the soft-start comparator is a negative input terminal used for voltage feedback. The first comparison input terminal FB is connected to the supply voltage VDD to provide a stable voltage signal. The second comparison input terminal SS is a first positive input terminal used for current feedback. The first positive input terminal is connected to a current source I. ss DC source I ss The first positive input terminal is used to provide a stable current signal to the first positive input terminal. The high and low voltage levels output by the second comparison input terminal SS are the first control signal. The soft-start comparator also includes a second positive input terminal, which is used to receive the reference voltage V. ref The first comparator output terminal COMP is connected to the fifth comparator input terminal of the second comparator U2, and the first comparator output terminal COMP is grounded through the twelfth resistor R12 and the fifth capacitor C5. G exists in the chip. COMP .

[0040] In this embodiment, the soft-start comparator operates as follows: Initially upon power-up, the second comparison input terminal SS is low. As the first control chip U3 starts, the voltage of the second comparison input terminal SS gradually increases, slowly charging the fourth capacitor C4. During this process, since the output port voltage is not yet fully established, the output voltage is low, and the high / low level state of the voltage of the first comparison input terminal FB cannot be determined. Therefore, it cannot be compared with the level of the second comparison input terminal SS. Consequently, the output level of the first comparison output terminal COMP may be either high or low. When the circuit is operating normally, the voltage of the first comparison input terminal FB is greater than the voltage of the first comparison input terminal FB; therefore, the first comparison output terminal COMP outputs a low-level voltage. When a short circuit occurs at the output port, the operating power supply at the first comparison input terminal FB drops to 0. At this time, the voltage of the second comparison input terminal SS is greater than the voltage of the first comparison input terminal FB, and the first comparison output terminal COMP outputs a high-level voltage. Both the high and low levels output by the first comparison output terminal COMP are the second control signal.

[0041] It is understandable that by setting a soft-start comparator inside the first control chip U3, the first control chip U3 can output a low-level voltage during the initial power-on and normal operation of the circuit to ensure normal operation of the circuit; while when a fault such as a short circuit occurs at the output port, the first control chip U3 can output a high-level voltage to realize the disconnection control of the isolating switch module.

[0042] like Figure 4 As shown in the embodiment of this application, the soft-start protection module further includes a first comparison and judgment unit. The first comparison and judgment unit includes a first comparator U1. The first comparator U1 includes a third comparison input terminal, a fourth comparison input terminal, and a second comparison output terminal. The third comparison input terminal is connected to the second comparison input terminal SS to receive a first control signal. The fourth comparison input terminal is configured to receive the operating power supply VCC. The second comparison output terminal is configured to output a first comparison signal based on the comparison result between the first control signal and the operating power supply VCC. Specifically, the first comparison and judgment unit also includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17. The first comparator U1 also includes a first positive input terminal and a first negative input terminal. The first positive input terminal is connected to the operating power supply VCC, and the first negative input terminal is grounded. One end of the thirteenth resistor R13 is connected to the operating power supply VCC, and the other end is connected to the second comparison output terminal and one end of the fourteenth resistor R14. The other end of the fourteenth resistor R14 is connected to the fourth comparison input terminal. The fifteenth resistor R15 is connected to the third comparison input terminal. The sixteenth resistor R16 is connected to the fourth comparison input terminal. One end of the seventeenth resistor R17 is connected to the fourth comparison input terminal, and the other end of the seventeenth resistor R17 is grounded.

[0043] It is worth noting that, in this embodiment, when the voltage received at the third comparison input terminal of the first comparator U1 is less than the voltage at the fourth comparison input terminal, that is, when the operating power supply VCC is greater than the voltage at the second comparison input terminal SS, the second comparison output terminal outputs a high-level voltage; when the voltage received at the third comparison input terminal is greater than the voltage at the fourth comparison input terminal, that is, when the voltage at the second comparison input terminal SS is greater than the operating power supply VCC, the second comparison output terminal outputs a low-level voltage.

[0044] It is understandable that by setting the first comparator U1 to judge the voltage at the second comparison input terminal SS, and by comparing the voltage at the second comparison input terminal SS with the working power supply VCC, a first comparison signal of high or low level is output.

[0045] like Figure 5 As shown in the embodiment of this application, the soft-start protection module further includes a second comparison and judgment unit. The second comparison and judgment unit includes a second comparator U2, which includes a fifth comparison input terminal, a sixth comparison input terminal, and a third comparison output terminal. The fifth comparison input terminal is connected to the first comparison output terminal to receive a second control signal. The fifth comparison input terminal is configured to receive the operating power supply VCC, and the third comparison output terminal is configured to output a second comparison signal based on the comparison result between the second control signal and the operating power supply VCC. Specifically, the second comparison and judgment unit also includes a nineteenth resistor R19, a twenty-second resistor R22, a twenty-fifth resistor R25, a twenty-sixth resistor R26, and a seventh capacitor C7. The second comparator U2 also includes a second positive input terminal and a second negative input terminal. The second negative input terminal is connected to the operating power supply VCC, and the second positive input terminal is grounded. One end of the nineteenth resistor R19 is connected to the operating power supply VCC, and the other end is connected to the third comparison output terminal. The twenty-second resistor R22 is connected to the fifth comparison input terminal, and the twenty-fifth resistor R25 is connected to the sixth comparison input terminal. One end of the twenty-sixth resistor R26 is connected to the sixth comparison input terminal, and the other end is grounded. One end of the seventh capacitor C7 is connected to the third comparison output terminal, and the other end is grounded.

[0046] It is worth noting that, in this embodiment, when the voltage received at the fifth comparison input terminal of the second comparator U2 is less than the voltage at the sixth comparison input terminal, that is, when the voltage of the second control signal is less than the operating power supply VCC, the third comparison output terminal outputs a high-level voltage; when the voltage received at the fifth comparison input terminal is greater than the voltage at the sixth comparison input terminal, that is, when the voltage of the second control signal is greater than the operating power supply VCC, the third comparison output terminal outputs a low-level voltage.

[0047] It is understandable that by setting the second comparator U2 to judge the voltage at the first comparator output terminal COMP, and by comparing the voltage at the first comparator output terminal COMP with the operating power supply VCC, a second comparator signal with high or low levels is output.

[0048] like Figure 5 As shown in the embodiment of this application, the soft-start protection module further includes a logic judgment unit U2A. The logic judgment unit U2A includes a first logic input terminal A, a second logic input terminal B, and a logic output terminal Y. The first logic input terminal A is connected to the second comparison output terminal B through a 20th resistor R20 to receive a first comparison signal. The second logic input terminal B is connected to the third comparison output terminal through a 23rd resistor R23 to receive a second comparison signal. The logic output terminal Y is configured to output an execution signal based on the logic operation result of the first comparison signal and the second comparison signal.

[0049] Specifically, the logic judgment unit includes a logic judgment circuit composed of NOR gates. Its judgment logic includes: the logic output terminal Y outputs a high level only when both the first logic input terminal A and the second logic input terminal B are low; otherwise, the logic output terminal Y outputs a low level. That is, when the first logic input terminal A is low and the second logic input terminal B is high, the logic output terminal Y outputs a low level; when the second logic input terminal B is low and the first logic input terminal A is high, the logic output terminal Y also outputs a low level; and when both the first logic input terminal A and the second logic input terminal B are high, the logic output terminal Y also outputs a low level. In other words, the logic output terminal Y outputs a high-level execution signal only when both the first comparison signal and the second comparison signal are low; when both the first comparison signal and the second comparison signal are high or their levels are inconsistent, the logic output terminal Y outputs a low-level execution signal.

[0050] Understandably, the logic judgment unit U2A is configured to judge the high and low levels of the first comparison signal output by the first comparator U1 and the second comparison signal output by the second comparator U2. When both the first comparison signal and the second comparison signal are low, it indicates that the voltage at SS and the voltage at COMP are both greater than VCC. At this time, a fault such as a short circuit occurs at the output port. The low-level execution signal can control the first switch module to conduct, thereby causing the processor module to output a cut-off signal to control the isolation switch module to disconnect.

[0051] like Figure 6As shown in the embodiment of this application, the protection circuit further includes a second switch module. The second switch module includes a first control terminal, a first connection terminal, and a second connection terminal. The first control terminal is connected to the logic output terminal to receive an execution signal; the first connection terminal is connected to the isolating switch module to receive an enable signal; and the second connection terminal is grounded. The first control terminal is configured to connect the first connection terminal and the second connection terminal based on the execution signal, so that the enable signal is grounded. Specifically, the second switch module includes a first transistor Q4, a twenty-first resistor R21, and a twenty-fourth resistor R24. The base of the first transistor Q4 is configured as the first control terminal, used to connect to the first control terminal through the twenty-first resistor R21 to receive the execution signal. The collector of the first transistor Q4 is configured as the first connection terminal, used to connect to the isolating switch module. The emitter of the first transistor Q4 is configured as the second connection terminal, used to ground. The twenty-fourth resistor R24 ​​is connected between the base and emitter of the first transistor Q4.

[0052] In this embodiment, the first transistor Q4 is an NPN transistor. When the base of the first transistor Q4 receives a low-level execution signal, the collector and emitter of the first transistor Q4 are not conducting; while when the base of the first transistor Q4 receives a high-level execution signal, the collector and emitter of the first transistor Q4 are conducting. At this time, the isolating switch module is connected to the first transistor Q4, and the enable signal flowing into the isolating switch module is grounded through the first transistor Q4, thereby causing the isolating switch module to disconnect after lacking the control of the enable signal.

[0053] Understandably, by controlling the first transistor Q4 to conduct, the enable signal is guided to the ground terminal, thereby causing the isolating switch module to be unable to maintain the conducting state and to disconnect, thus isolating the input port and the output port, and preventing a fire caused by the failure to disconnect in time after a short circuit in the output port.

[0054] like Figure 7As shown in this embodiment, the first switch module includes a second control terminal, a third connection terminal, and a fourth connection terminal. The second control terminal is connected to the logic output terminal to receive an execution signal; the third connection terminal is connected to the power supply terminal and the processor module respectively; and the fourth connection terminal is grounded. The second control terminal is configured to connect the third connection terminal and the fourth connection terminal based on the execution signal, so that the power supply is grounded. Specifically, the first switch module includes a second transistor Q5, a twenty-seventh resistor R27, a twenty-eighth resistor R28, and a twenty-ninth resistor R29. The base of the second transistor Q5 is configured as the second control terminal, used to connect to the second control terminal through the twenty-eighth resistor R28 to receive the execution signal; the collector of the second transistor Q5 is configured as the third connection terminal, used to connect to the power supply VCC and the processor module through the twenty-seventh resistor R27; and the emitter of the second transistor Q5 is configured as the fourth connection terminal for grounding. The twenty-ninth resistor R29 is connected between the base and emitter of the second transistor Q5.

[0055] In this embodiment, the second transistor Q5 is an NPN transistor. When the base of the second transistor Q5 receives a low-level execution signal, the collector and emitter of the second transistor Q5 are not conducting. At this time, the operating power supply VCC flows to the processor module. Under the trigger of the operating power supply VCC, the processor module continuously sends a high-level enable signal to the isolating switch module, thereby enabling the isolating switch module to maintain its conducting state. When the base of the second transistor Q5 receives a high-level execution signal, the collector and emitter of the second transistor Q5 conduct. At this time, the operating power supply VCC flows to the ground terminal. Under the trigger of no operating power supply VCC, the processor module sends a low-level cutoff signal to the isolating switch module, and the isolating switch module is disconnected under the action of the cutoff signal.

[0056] It is understandable that by controlling the conduction of the second transistor Q5 to guide the working power supply VCC to the ground terminal, the processor module sends a cut-off signal to the isolating switch module. After receiving the cut-off signal, the isolating switch module disconnects, thereby isolating the input port and the output port and preventing a fire caused by failure to disconnect in time after a short circuit in the output port.

[0057] like Figure 8As shown in the embodiment of this application, the disconnect switch module includes a first disconnect switch Q1 and a second disconnect switch Q2. The first disconnect switch Q1 includes a first controlled terminal, a first isolated terminal, and a second isolated terminal. The first controlled terminal and the first isolated terminal are both connected to the input port, and the second isolated terminal is connected to the output port. The second disconnect switch Q2 includes a second controlled terminal, a third isolated terminal, and a fourth isolated terminal. The second controlled terminal is connected to the processor module and the first connection terminal respectively to receive an enable signal. The third isolated terminal is connected to the input port and the first isolated terminal respectively, and the fourth isolated terminal is grounded. Specifically, the isolating switch module also includes a first resistor R1, a second resistor R2, a third resistor R3, a fifth resistor R5, an eighteenth resistor R18, a thirtieth resistor R30, and a fifth diode D5; the first isolating switch Q1 includes a first MOSFET, wherein the gate of the first MOSFET is configured as a first controlled terminal for connection to a third isolation terminal via the second resistor R2 and the third resistor R3, the source of the first MOSFET is configured as a first isolation terminal for connection to the input port, and the drain of the first MOSFET is configured as a second isolation terminal for connection to the output port, wherein the first resistor R1 is connected to the input... Between the port and the second resistor R2; the second isolating switch Q2 includes a transistor, the base of which is configured as the second controlled terminal, for connection to the processor module and the first connection terminal via the eighteenth resistor R18 respectively, the second controlled terminal receiving the enable signal sent by the processor module, the collector of which is connected to the third resistor R3, and the emitter of which is grounded; wherein, the base and emitter of the transistor are connected by a fifth resistor R5 and a thirtieth resistor R30, and the fifth resistor and the thirtieth resistor R30 are connected in parallel; the anode of the fifth diode is connected to the processor module, and the cathode of the fifth diode is connected to the second controlled terminal.

[0058] Understandably, when the isolating switch module is on, the input port and output port are connected, and the input power flows in from the connection terminal KL30 and flows to the output port through the input port. When a short circuit or other fault occurs in the circuit near the output port, the isolating switch module can disconnect in time under control, thereby cutting off the connection between the input port and the output port, thus preventing the short circuit current from continuing to act and burning out the circuit.

[0059] like Figure 8As shown in the embodiment of this application, the processor module includes a processor chip U4, namely an MCU (Microcontroller Unit). The processor chip U4 includes a status judgment pin and an enable pin. The status judgment pin is connected to the collector (i.e., the third connection terminal) of the second transistor Q5. When the second transistor Q5 is off, the status judgment pin is used to receive the working power supply VCC, and the enable pin outputs a high-level enable signal. When the second transistor Q5 is on, the working power supply VCC flows to the ground terminal, the potential of the status judgment pin is pulled low, and the enable pin outputs a low-level cutoff signal.

[0060] Understandably, by setting the processor module to judge the status of the circuit at the output port, when the circuit at the output port is normal, the processor module continuously outputs an enable signal to keep the isolating switch module always open; when a fault such as a short circuit is detected at the output port, the processor module outputs a cut-off signal, thereby causing the isolating switch module to disconnect the connection between the input port and the output port, thus preventing damage to the components in the circuit.

[0061] like Figure 9 As shown in the embodiment of this application, an output execution module is also included. The output execution module includes a transformer T1 and a third disconnect switch Q3. The transformer includes a first input winding, a second input winding, and multiple output windings. The first input winding includes a first end and a second end, and the second input winding includes a third end and a fourth end. The first end is connected to an input port, the second end is connected to the third disconnect switch, the third end is connected to the power supply voltage VDD, and the fourth end is grounded. The multiple output windings are configured as multiple output ports. The third disconnect switch Q3 includes a third controlled end, a fifth isolated end, and a sixth isolated end. The third controlled end is connected to a soft-start protection unit, the fifth isolated end is connected to the second end of the transformer, and the sixth isolated end is connected to the soft-start protection unit and grounded. Specifically, the output execution module also includes a first diode D1, a second diode D2, a fourth diode D4, a sixth diode D6, a seventh resistor R7, an eleventh resistor R11, a first capacitor C1, a second capacitor C2, and a sixth capacitor C6; the third isolation switch Q3 includes a second MOSFET, the gate of which is configured as the third controlled terminal for connecting to the data ready pin DR of the first control chip U3; the source of which is configured as the fifth isolation terminal for connecting to the second terminal of the transformer and the input port; and the drain of which is configured as the sixth isolation terminal for connecting to the current feedback pin CS of the first control chip U3 and also grounded through the eleventh resistor R11.

[0062] In this embodiment, the first diode D1 includes a Zener diode. The first diode D1 and the first capacitor C1 are connected in parallel between the first and second terminals of the first input winding of the transformer. The anode of the first diode D1 is connected to the input port, and the cathode of the first diode D1 is connected to the second terminal via a fourth diode D4. The cathode of the fourth diode D4 is connected to the cathode of the first diode D1, and the anode of the fourth diode D4 is connected to both the second terminal and the source of the second MOSFET. The anode of the sixth diode D6 is connected to the third terminal of the second input winding. One end of the sixth capacitor C6 is connected to both the cathode of the sixth diode D6 and the supply voltage VDD, and the other end of the sixth capacitor C6 is grounded. The fourth terminal is also grounded. It is worth noting that in this embodiment, multiple output windings are included, and these multiple output windings have the same structure, such as... Figure 9 As shown, transformer T1 includes n-1 output windings, where n is a positive integer greater than 1. Each output winding includes a second diode D2 and a second capacitor C2. The anode of the second diode D2 is connected to the fifth terminal of the output winding, and the cathode of the second diode D2 is configured as the output port. One end of the second capacitor C2 is connected to the cathode of the second diode D2, and the other end of the second capacitor C2 is connected to the fifth terminal of the output winding and grounded.

[0063] It is understandable that by setting transformer T1 in the output execution module, electrical isolation between the input port and the output port is achieved, preventing high voltage or dangerous voltage from the output terminal from being conducted to the input terminal. At the same time, by setting the turns ratio between the input winding and the output winding of transformer T1, the voltage of the output port can be increased or decreased, thereby realizing voltage level control. Furthermore, setting transformer T1 can also block the DC signal at the output terminal, transmitting only the AC signal, thus achieving signal isolation between the input port and the output port.

[0064] The working process and principle of the protection circuit provided in this application embodiment:

[0065] KL30 is the power output terminal of the low-voltage battery. When KL30 is powered on, the MCU receives the power-on signal and outputs a high-level enable signal through the enable pin EN. The enable signal controls the second isolating switch Q2 to conduct. The conducting second isolating switch Q2 guides the current of KL30 to ground. The current flows through the second resistor R2, causing the gate voltage of the first isolating switch Q1 to rise, and the first isolating switch Q1 conducts. The current of KL30 is then used as the power input to the first control chip U3, and the first control chip U3 starts to work. Initially, the voltage of the second comparator input terminal SS of the first control chip U3 is low. After the first control chip U3 stabilizes, the voltage of the second comparator input terminal SS slowly rises, charging the fourth capacitor C4. At this time, the operating power supply VCC connected to the fourth comparator input terminal of the first comparator U1 is greater than the level of the third comparator input terminal. Therefore, the first comparator output terminal of the first comparator U1 outputs a high level. If, at this time, the flyback power supply outputs, before the output voltage is fully established, the output terminal needs to charge the second capacitor C2. Therefore, the output voltage will be pulled low. During this process, the voltage at the first comparator input terminal FB cannot be determined and cannot be compared with the voltage at the second comparator input terminal SS. At this time, the first comparator output terminal COMP of the soft-start comparator may output a high-level voltage or a low-level voltage. Since the voltage level of the first comparator output terminal COMP cannot be determined, the voltage output of the third comparator output terminal of the second comparator U2 also cannot be determined. However, according to the judgment condition of the logic judgment unit U2A, that is, when the first comparator signal output by the first comparator U1 is high, regardless of the level of the second comparator U2 output, the logic judgment unit U2A will output a low level. Therefore, neither the first switch module nor the second switch module will be triggered to conduct, which means that the protection function of the circuit will not be falsely triggered during the flyback power supply startup process.

[0066] When the flyback power supply is operating normally, the fourth capacitor C4 is fully charged. At this time, the second comparator input SS is at a high level. For the first comparator U1, the voltage at the second comparator input SS is greater than the operating power supply VCC, so the second comparator output is low, meaning the first logic input A of the logic judgment unit U2A receives a low-level voltage. However, the voltage at the first comparator input FB of the soft-start comparator is greater than the voltage at the second comparator input SS, so the first comparator output COMP is low. For the second comparator U2, the operating power supply VCC is greater than the voltage at the third comparator input, so the second comparator output is high, meaning the second logic input B receives a high-level voltage. According to the output logic of the logic judgment unit U2A, it still outputs a low level. Therefore, the first and second switching modules remain in the off state, meaning that the circuit's protection function will not be triggered after the flyback power supply starts.

[0067] When the output of the third isolating switch Q3 of the flyback power supply is short-circuited, or any output of another output winding is short-circuited, the supply voltage VDD will become 0V. At this time, the first comparator input terminal FB is at a low level. Therefore, the voltage of the first comparator input terminal FB is less than the voltage of the second comparator input terminal SS. Therefore, the first comparator output terminal COMP outputs a high level. For the first comparator U1, the voltage of the fourth comparator input terminal is less than the voltage of the third comparator input terminal. Therefore, the first comparator output terminal outputs a low level. According to the output logic of the logic judgment unit U2A, when the first logic input terminal A is at a low level and the second logic input terminal B is at a low level, the logic output terminal Y outputs a high level. At this time, the first and second switch modules are triggered at a high level, the operating power supply of the input MCU is pulled low, and the enable signal is also guided to the ground terminal. After the enable signal is pulled low, the second isolating switch Q2 is triggered to open, and the connection of the first isolating switch Q1 is also disconnected, and the power supply output is cut off. Simultaneously, the MCU also receives a short-circuit fault signal. Since there is no output, the soft-start protection module cuts off the power supply. The second comparator input SS discharges and is at a low level. The first comparator input FB, lacking power supply voltage, is also at a low level. For the first comparator U1, the voltage at the second comparator input is greater than the voltage at the first comparator input. Therefore, the second comparator output is high, meaning the first logic input A of the logic judgment unit U2A is high. At this point, the logic judgment unit U2A outputs a low level, causing the second switch module to disconnect, and the power supply resumes output. However, because the fault persists, the protection is triggered again, causing the power supply to disconnect, repeating this process multiple times. Because the MCU receives the short-circuit fault signal, it outputs a low-level cutoff signal. This low-level cutoff signal controls the second isolating switch Q2 to disconnect, and similarly, the first isolating switch Q1 also disconnects. At this point, the flyback power supply locks up and will not resume output.

[0068] In summary, the protection circuit provided in this application adds an isolation control circuit to the flyback auxiliary source. If the circuit triggers protection, it can effectively isolate the output and input ports, thus preventing circuit damage. Furthermore, by issuing a fault signal through the MCU, information such as short-circuit faults can be obtained promptly. This protection circuit has a simple structure and low cost; relying on the characteristics of the first control chip U3 itself plus a simple auxiliary circuit, it can effectively lock out the protection; and the protection signal can be reported to the MCU; its single-stage structure means the fault location is relatively singular, allowing for unified and effective transmission of protection faults to the signal protection node; and it includes a soft-start feature to prevent false protection during startup.

[0069] This application provides a vehicle, including: a battery, on-board electrical components, and a protection circuit as provided in any of the above embodiments; wherein the battery is connected to the on-board electrical components, and the protection circuit is connected between the battery and the on-board electrical components. The specific connection method, working principle, and beneficial effects of the protection circuit have been described in the above embodiments, and will not be repeated here.

[0070] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although this application has disclosed preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A protection circuit, characterized in that, include: A disconnect switch module, wherein the disconnect switch module is connected to the input port and the output port of the protection circuit; A processor module, which is connected to the disconnector module; A soft-start protection module is connected to the output port; The first switch module is connected to both the soft-start protection module and the processor module.

2. The protection circuit according to claim 1, characterized in that, The soft-start protection module includes a soft-start protection unit, which includes a soft-start comparator. The soft-start comparator has a first comparison input terminal, a second comparison input terminal, and a first comparison output terminal. The first comparison input terminal is connected to the output port and is configured to acquire the current signal of the output port. The second comparison input is connected to an internal DC source, and the second comparison input is grounded through a fourth capacitor. The second comparison input is configured to output a first control signal based on the internal DC source. The first comparison output terminal is configured to output a second control signal based on the level comparison result of the first comparison input terminal and the second comparison input terminal.

3. The protection circuit according to claim 2, characterized in that, The soft-start protection module further includes a first comparison and judgment unit, which includes a first comparator. The first comparator includes a third comparison input terminal, a fourth comparison input terminal, and a second comparison output terminal. The third comparison input terminal is connected to the second comparison input terminal to receive the first control signal. The fourth comparison input terminal is configured to receive the operating power supply. The second comparison output terminal is configured to output a first comparison signal based on the comparison result between the first control signal and the operating power supply.

4. The protection circuit according to claim 3, characterized in that, The soft-start protection module further includes a second comparison and judgment unit, which includes a second comparator. The second comparator includes a fifth comparison input terminal, a sixth comparison input terminal, and a third comparison output terminal. The fifth comparison input terminal is connected to the first comparison output terminal to receive the second control signal. The fifth comparison input terminal is configured to receive the operating power supply. The third comparison output terminal is configured to output a second comparison signal based on the comparison result between the second control signal and the operating power supply.

5. The protection circuit according to claim 4, characterized in that, The soft-start protection module further includes a logic judgment unit, which includes a first logic input terminal, a second logic input terminal, and a logic output terminal. The first logic input terminal is connected to the second comparison output terminal to receive the first comparison signal. The second logic input terminal is connected to the third comparison output terminal to receive the second comparison signal; The logic output terminal is configured to output an execution signal based on the logic operation result of the first comparison signal and the second comparison signal.

6. The protection circuit according to claim 5, characterized in that, The protection circuit further includes a second switch module, which includes a first control terminal, a first connection terminal, and a second connection terminal. The first control terminal is connected to the logic output terminal to receive the execution signal. The first connection terminal is connected to the disconnect switch module to receive an enable signal, and the second connection terminal is grounded; The first control terminal is configured to connect the first connection terminal and the second connection terminal based on the execution signal, so that the enable signal is grounded.

7. The protection circuit according to claim 5, characterized in that, The first switch module includes a second control terminal, a third connection terminal, and a fourth connection terminal. The second control terminal is connected to the logic output terminal to receive the execution signal. The third connection terminal is connected to the power supply terminal and the processor module respectively, and the fourth connection terminal is grounded; The second control terminal is configured to connect the third connection terminal and the fourth connection terminal based on the execution signal, so as to ground the operating power supply.

8. The protection circuit according to claim 6, characterized in that, The disconnector module includes a first disconnector and a second disconnector. The first disconnector includes a first controlled terminal, a first isolated terminal, and a second isolated terminal. Both the first controlled terminal and the first isolated terminal are connected to the input port, and the second isolated terminal is connected to the output port. The second disconnect switch includes a second controlled terminal, a third isolated terminal, and a fourth isolated terminal. The second controlled terminal is connected to the processor module and the first connection terminal respectively to receive the enable signal. The third isolated terminal is connected to the input port and the first isolated terminal respectively. The fourth isolated terminal is grounded.

9. The protection circuit according to claim 2, characterized in that, It also includes an output execution module, which includes a transformer and a third disconnect switch. The transformer includes a first input winding, a second input winding, and multiple output windings. The first input winding includes a first end and a second end, and the second input winding includes a third end and a fourth end. The first end is connected to the input port, the second end is connected to the third disconnect switch, the third end is connected to the power supply voltage, the fourth end is grounded, and the multiple output windings are configured as the output port. The third disconnecting switch includes a third controlled terminal, a fifth disconnecting terminal, and a sixth disconnecting terminal. The third controlled terminal is connected to the soft-start protection unit, the fifth disconnecting terminal is connected to the second terminal, and the sixth disconnecting terminal is connected to the soft-start protection unit and grounded.

10. A vehicle, characterized in that, include: Batteries, vehicle electrical components, and protection circuits as described in any one of claims 1-9; The battery is connected to the vehicle-mounted electrical components, and the protection circuit is connected between the battery and the vehicle-mounted electrical components.

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