Current protection circuit, battery and machine equipment
By introducing a hysteresis comparator module and a self-locking function into the current protection circuit, the problems of weak anti-interference capability and lack of self-locking in the overcurrent protection circuit are solved, thereby improving the stability and reliability of the circuit and extending the life of the device.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-03-17
AI Technical Summary
Existing overcurrent protection circuits have weak anti-interference capabilities and are prone to frequent output jumps in the comparison module due to fluctuations in the sampling current. Furthermore, they lack self-locking functionality, causing the circuit to switch back and forth between overcurrent and normal states, thus shortening the lifespan of the devices.
By employing a hysteresis comparison module and a self-locking function, the overcurrent protection recovery point is set below the normal recovery point to avoid frequent jumps and maintain the fault state under overcurrent conditions. The addition of hysteresis function and self-locking mechanism improves stability.
It improves the stability and reliability of the overcurrent protection circuit, avoids frequent switching between overcurrent and normal states, and extends the life of the device.
Smart Images
Figure CN224006495U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power electronics technology, specifically to a current protection circuit, a battery, and a machine device. Background Technology
[0002] The basic principle of overcurrent protection circuits is that when the current in the circuit exceeds a preset maximum value, the protection circuit will trigger and cut off the power supply or take other measures to prevent the current from continuing to increase, which could lead to equipment damage or safety accidents. In the field of power electronics, overcurrent protection circuits are generally used to block the drive of MOSFETs, so as to prevent the MOSFETs from being damaged due to overcurrent.
[0003] Existing overcurrent or short-circuit protection mainly employs two solutions: self-resetting fuse current limiting and MCU output shutdown upon detecting an anomaly. However, current overcurrent protection circuits have weak anti-interference capabilities. Even slight fluctuations in the input signal near the threshold can cause the comparator output to jump, potentially damaging the circuit over time and creating false overcurrent warnings. Furthermore, existing overcurrent protection circuits lack a latching function. When an overcurrent occurs, a protection signal is triggered, causing the current to drop. Once the current falls below the overcurrent threshold, the circuit returns to normal, and the current continues to rise, triggering the protection signal again when the overcurrent threshold is reached. Without external intervention, the circuit switches back and forth between protection and normal states, easily shortening component lifespan and potentially damaging the protection circuit. Utility Model Content
[0004] In view of this, the present invention provides a current protection circuit, a battery, and a machine device to solve the problems of weak anti-interference ability and lack of self-locking function in current overcurrent protection circuits.
[0005] In a first aspect, this utility model provides a current protection circuit, the circuit comprising: a hysteresis comparator module, a control module, and a switching module, wherein...
[0006] The first input terminal of the hysteresis comparator is connected to a reference voltage, the second input terminal of the hysteresis comparator is connected to a sampling current, the output terminal of the hysteresis comparator is connected to the input terminal of the control module, the output terminal of the control module is connected to the control terminal of the switch module, the first terminal of the switch module is connected to the second input terminal of the hysteresis comparator, and the second terminal of the switch module is grounded.
[0007] This utility model provides a current protection circuit that, by employing a hysteresis comparator module, sets the overcurrent protection recovery point below the normal recovery point, preventing the overcurrent protection from automatically recovering after activation and avoiding frequent output jumps in the comparator module due to sampling current fluctuations. Simultaneously, a self-locking mechanism is used, ensuring that the overcurrent signal remains in a fault state without an unlocking signal in the event of an overcurrent, preventing repeated switching between normal and fault states. By adding hysteresis and self-locking functions to the current protection circuit, the degree of software dependence on protection actions is reduced, improving the stability and reliability of overcurrent protection.
[0008] In one optional implementation, the hysteresis comparison module includes a positive current hysteresis comparator and a negative current hysteresis comparator, wherein,
[0009] The non-inverting input of the positive current hysteresis comparator is connected to the reference voltage, the inverting input of the positive current hysteresis comparator is connected to the sampling current, and the output of the positive current hysteresis comparator is connected to the first input of the control module.
[0010] The non-inverting input of the negative current hysteresis comparator is connected to the sampling current, the inverting input of the negative current hysteresis comparator is connected to the reference voltage, and the output of the negative current hysteresis comparator is connected to the second input of the control module.
[0011] In one optional implementation, the control module includes a digital signal processor, a first input terminal of which is connected to the output terminal of the positive current hysteresis comparator, a second input terminal of which is connected to the output terminal of the negative current hysteresis comparator, and an output terminal of which is connected to the control terminal of the switching module.
[0012] In one optional implementation, the switching module includes a positive current transistor and a negative current transistor, wherein,
[0013] The control terminal of the positive current transistor is connected to the first output terminal of the digital signal processor, the first terminal of the positive current transistor is connected to the inverting input terminal of the positive current hysteresis comparator, and the second terminal of the positive current transistor is grounded.
[0014] The control terminal of the negative current transistor is connected to the second output terminal of the digital signal processor, the first terminal of the negative current transistor is connected to the inverting input terminal of the negative current hysteresis comparator, and the second terminal of the negative current transistor is grounded.
[0015] In one optional implementation, the circuit further includes an inverting module and a driving module, wherein,
[0016] The input terminal of the inverting module is connected to the output terminal of the hysteresis comparison module, and the output terminal of the inverting module is connected to the enable terminal of the driving module.
[0017] In one optional implementation, the reverse module includes a positive current diode, a negative current diode, and an overcurrent comparator, wherein,
[0018] The cathode of the positive current diode is connected to the output terminal of the positive current hysteresis comparator, and the anode of the positive current diode is connected to the inverting input terminal of the overcurrent comparator.
[0019] The cathode of the negative current diode is connected to the output terminal of the negative current hysteresis comparator, and the anode of the negative current diode is connected to the inverting input terminal of the overcurrent comparator.
[0020] The non-inverting input of the overcurrent comparator is connected to a reference voltage, and the output of the overcurrent comparator is connected to the enable terminal of the drive module.
[0021] In one optional implementation, the driving module includes a buffer and a driving chip, wherein,
[0022] The enable terminals of the buffer and the driver chip are both connected to the output terminal of the overcurrent comparator. The output terminal of the buffer is connected to the input terminal of the driver chip, and the output terminal of the driver chip is connected to the switching transistor.
[0023] Secondly, the present invention provides a battery, the battery including the current protection circuit of the first aspect or any corresponding embodiment described above.
[0024] By adding hysteresis and self-locking functions to the current protection circuit, the stability and reliability of overcurrent protection are improved, further ensuring the reliable operation of the battery.
[0025] Thirdly, the present invention provides a machine device, which includes the battery described in the second aspect above or any corresponding embodiment thereof.
[0026] By adding hysteresis and self-locking functions to the current protection circuit, the stability and reliability of overcurrent protection are improved, further ensuring the reliable operation of batteries and equipment. Attached Figure Description
[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0028] Figure 1 This is a schematic block diagram of the current protection circuit according to an embodiment of the present utility model;
[0029] Figure 2 This is a schematic diagram of a current protection circuit according to an embodiment of the present utility model;
[0030] Figure 3 This is a schematic diagram of another current protection circuit according to an embodiment of the present utility model;
[0031] Figure 4 This is a schematic diagram of another current protection circuit according to an embodiment of the present utility model;
[0032] Figure 5 This is a schematic diagram of another current protection circuit according to an embodiment of the present utility model;
[0033] Figure 6 This is a schematic diagram of another current protection circuit according to an embodiment of the present utility model;
[0034] Figure 7 This is a schematic diagram of another current protection circuit according to an embodiment of the present utility model. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0036] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0038] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0039] This invention provides a current protection circuit for monitoring the current in a circuit. For example... Figure 1 As shown, the current protection circuit includes a hysteresis comparator module, a control module, and a switching module. The first input terminal of the hysteresis comparator module is connected to a reference voltage, the second input terminal is connected to the sampling current, the output terminal of the hysteresis comparator module is connected to the input terminal of the control module, the output terminal of the control module is connected to the control terminal of the switching module, the first terminal of the switching module is connected to the second input terminal of the hysteresis comparator module, and the second terminal of the switching module is grounded. The grounding of the switching module is not... Figure 1 As shown in the image.
[0040] Specifically, the hysteresis comparator module is a comparator module with hysteresis function. By using the hysteresis comparator module, the overcurrent protection recovery point can be set below the normal recovery point, achieving the purpose of preventing self-recovery after overcurrent protection action and avoiding frequent output jumps of the comparator module due to sampling current fluctuations. When there is a positive current, the monitored current is input to the second input terminal of the hysteresis comparator module after passing through the voltage divider resistor, and the first input terminal of the hysteresis comparator module is connected to the reference voltage. When the current is normal, the voltage at the first input terminal is higher than the voltage at the second input terminal, and the hysteresis comparator module outputs a high level to the control module; when there is an overcurrent, the voltage at the first input terminal is lower than the voltage at the second input terminal, and the hysteresis comparator module outputs a low level to the control module. When the control module detects the low level, it senses the overcurrent. At this time, it detects the duration of the low level and, after a preset delay based on this duration, outputs a high level to the switching module. This high level is the unlock signal. By controlling the switching module to conduct, the sampling current is pulled to ground. At this time, the second input terminal of the hysteresis comparator module is also pulled low, restoring the state where the voltage at the first input terminal is higher than the voltage at the second input terminal, thus unlocking the overcurrent fault. When the control module detects a high level, it does not perform any action. The preset time is set according to the protection requirements.
[0041] This utility model provides a current protection circuit that, by employing a hysteresis comparator module, sets the overcurrent protection recovery point below the normal recovery point, preventing the overcurrent protection from automatically recovering after activation and avoiding frequent output jumps in the comparator module due to sampling current fluctuations. Simultaneously, a self-locking mechanism is used, ensuring that the overcurrent signal remains in a fault state without an unlocking signal in the event of an overcurrent, preventing repeated switching between normal and fault states. By adding hysteresis and self-locking functions to the current protection circuit, the degree of software dependence on protection actions is reduced, improving the stability and reliability of overcurrent protection.
[0042] In one alternative implementation, such as Figure 2 As shown, the hysteresis comparator module includes a positive current hysteresis comparator and a negative current hysteresis comparator. The non-inverting input of the positive current hysteresis comparator is connected to a reference voltage, the inverting input is connected to the sampling current, and the output is connected to the first input of the control module. Similarly, the non-inverting input of the negative current hysteresis comparator is connected to the sampling current, the inverting input is connected to a reference voltage, and the output is connected to the second input of the control module.
[0043] Specifically, positive feedback is added to the positive current hysteresis comparator and the negative current hysteresis comparator, making them both comparators with hysteresis function. By using comparators with hysteresis, the overcurrent protection recovery point can be set below the normal recovery point, so that the overcurrent protection cannot recover on its own after the overcurrent protection is activated, thus avoiding frequent jumps in the comparator output caused by fluctuations in the sampling current.
[0044] Furthermore, when the sampled current is positive, the non-inverting input of the positive current hysteresis comparator is connected to the reference voltage, and the inverting input is connected to the sampled current. Under normal current conditions, the reference voltage is higher than the sampled output voltage, and the positive current hysteresis comparator outputs a high level to the control module. Under overcurrent conditions, the reference voltage is lower than the sampled output voltage, and the positive current hysteresis comparator outputs a low level to the control module.
[0045] When the sampled current is negative, the non-inverting input of the negative current hysteresis comparator is connected to the sampled current, and the inverting input is connected to the reference voltage. Under normal current conditions, the sampled output voltage is higher than the reference voltage, and the negative current hysteresis comparator outputs a high level to the control module. Under overcurrent conditions, the sampled output voltage is lower than the reference voltage, and the negative current hysteresis comparator outputs a low level to the control module. The voltage at the non-inverting input can be calculated from the voltage at the inverting input.
[0046] In one alternative implementation, such as Figure 3 As shown, the control module includes a digital signal processor (DSP). The first input terminal of the DSP is connected to the output terminal of the positive current hysteresis comparator, the second input terminal is connected to the output terminal of the negative current hysteresis comparator, and the output terminal of the DSP is connected to the control terminal of the switching module. Figure 4 As shown, the switching module includes a positive current transistor and a negative current transistor. The control terminal of the positive current transistor is connected to the first output terminal of the digital signal processor, and its first terminal is connected to the inverting input terminal of a positive current hysteresis comparator. The second terminal of the positive current transistor is grounded. Similarly, the control terminal of the negative current transistor is connected to the second output terminal of the digital signal processor, its first terminal is connected to the inverting input terminal of a negative current hysteresis comparator, and its second terminal is grounded. Neither the grounding of the positive current transistor nor the grounding of the negative current transistor is... Figure 3 and Figure 4 As shown in the image.
[0047] Specifically, when the digital signal processor (DSP) detects a low level output from the positive current hysteresis comparator, it senses an overcurrent. It then detects the duration of the low level and, after a preset delay, outputs a high level to the control terminal of the positive current transistor, turning it on and pulling the sampled current to ground. At this time, the inverting input of the positive current hysteresis comparator is also pulled low, restoring the state where the voltage at the non-inverting input is higher than the voltage at the inverting input, thus unlocking the overcurrent fault. When the DSP detects a high level output from the positive current hysteresis comparator, it takes no further action.
[0048] Similarly, when the digital signal processor detects a low level at the output of the negative current hysteresis comparator, it senses an overcurrent. It then detects the duration of the low level and, after a preset delay, outputs a high level to the control terminal of the negative current transistor, turning it on and pulling the reference voltage to ground. At this time, the inverting input of the negative current hysteresis comparator is also pulled low, restoring the state where the voltage at the non-inverting input is higher than the voltage at the inverting input, thus unlocking the overcurrent fault. When the digital signal processor detects a high level at the output of the negative current hysteresis comparator, it takes no action.
[0049] In one alternative implementation, such as Figure 5 As shown, the current protection circuit also includes an inverting module and a driving module. The input of the inverting module is connected to the output of the hysteresis comparator module, and the output of the inverting module is connected to the enable terminal of the driving module.
[0050] Specifically, during an overcurrent event, the hysteresis comparator outputs a low level. This low level is inverted to a high level by the inverter module. When the enable pin of the driver module is high, all drivers are disabled, achieving circuit safety protection. When the current is normal, the hysteresis comparator outputs a high level. The inverter module then cuts off this high-level signal.
[0051] Furthermore, under normal circumstances, the current protection circuit will have multiple positive current protection circuits and multiple negative current protection circuits. To ensure that all drives can be shut down regardless of which current protection circuit detects an overcurrent, this embodiment inputs all current protection signals to the inverting module and the driving module.
[0052] In one alternative implementation, such as Figure 6As shown, the inverting module includes a positive current diode, a negative current diode, and an overcurrent comparator. The cathode of the positive current diode is connected to the output of the positive current hysteresis comparator, and the anode of the positive current diode is connected to the inverting input of the overcurrent comparator. The cathode of the negative current diode is connected to the output of the negative current hysteresis comparator, and the anode of the negative current diode is connected to the inverting input of the overcurrent comparator. The non-inverting input of the overcurrent comparator is connected to a reference voltage, and the output of the overcurrent comparator is connected to the enable terminal of the drive module.
[0053] Specifically, when the sampled current is positive and normal, the positive current hysteresis comparator outputs a high level to the positive current diode. Since the cathode of the positive current diode is connected to the output of the positive current hysteresis comparator, the positive current diode cuts off this high-level signal. Similarly, when the sampled current is negative and normal, the negative current hysteresis comparator outputs a high level to the negative current diode. Since the cathode of the negative current diode is connected to the output of the negative current hysteresis comparator, the negative current diode cuts off this high-level signal.
[0054] When the sampled current is positive and overcurrent, the low-level output of the positive current hysteresis comparator is input to the inverting input of the overcurrent comparator via the positive current diode. Since the voltage at the non-inverting input of the overcurrent comparator is higher than the voltage at the inverting input, the overcurrent comparator outputs a high level to the driver module. Similarly, when the sampled current is negative and overcurrent, the low-level output of the negative current hysteresis comparator is input to the inverting input of the overcurrent comparator via the negative current diode. Since the voltage at the non-inverting input of the overcurrent comparator is higher than the voltage at the inverting input, the overcurrent comparator outputs a high level to the driver module.
[0055] In one alternative implementation, such as Figure 7 As shown, the drive module includes a buffer and a drive chip. The enable terminals of both the buffer and the drive chip are connected to the output of the overcurrent comparator. The output of the buffer is connected to the input of the drive chip, and the output of the drive chip is connected to a switching transistor such as a MOSFET or IGBT. The connection relationship between the drive chip and the MOSFET or IGBT is not shown.
[0056] Specifically, the output of the overcurrent comparator is connected to both the enable pin of the buffer and the enable pin of the driver chip. The output of the buffer is a PWM signal, which is directly supplied to the input of the driver chip. When an overcurrent occurs, both the enable pins of the buffer and the driver chip are set to a high level. After the buffer is enabled, it outputs a PWM signal to the input of the driver chip. After the driver chip is enabled, it shuts down all drives, achieving circuit safety protection. Under normal circumstances, there are multiple overcurrent protection circuits. By sending different overcurrent protection signals to the enable pins of the buffer and the driver chip, it can be ensured that regardless of which path experiences an overcurrent, a fault signal is output to the enable pin of the driver chip, shutting down all drives and achieving circuit safety protection.
[0057] This utility model provides a battery, the battery comprising: Figures 1-7 The current protection circuit shown is shown.
[0058] By adding hysteresis and self-locking functions to the current protection circuit, the stability and reliability of overcurrent protection are improved, further ensuring the reliable operation of the battery.
[0059] This utility model provides a machine device, which includes the aforementioned battery.
[0060] By adding hysteresis and self-locking functions to the current protection circuit, the stability and reliability of overcurrent protection are improved, further ensuring the reliable operation of batteries and equipment.
[0061] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A current protection circuit, characterized by, The circuit comprises a hysteresis comparison module, a control module and a switch module, wherein, a first input end of the hysteresis comparison module is connected with a reference voltage, a second input end of the hysteresis comparison module is connected with a sampling current, an output end of the hysteresis comparison module is connected with an input end of the control module, an output end of the control module is connected with a control end of the switch module, a first end of the switch module is connected with the second input end of the hysteresis comparison module, and a second end of the switch module is connected with the ground. The hysteresis comparison module comprises a positive current hysteresis comparator and a negative current hysteresis comparator, wherein, a non-inverting input end of the positive current hysteresis comparator is connected with the reference voltage, an inverting input end of the positive current hysteresis comparator is connected with the sampling current, and an output end of the positive current hysteresis comparator is connected with a first input end of the control module; a non-inverting input end of the negative current hysteresis comparator is connected with the sampling current, an inverting input end of the negative current hysteresis comparator is connected with the reference voltage, and an output end of the negative current hysteresis comparator is connected with a second input end of the control module.
2. The current protection circuit of claim 1, wherein, The control module comprises a digital signal processor, a first input end of the digital signal processor is connected with the output end of the positive current hysteresis comparator, a second input end of the digital signal processor is connected with the output end of the negative current hysteresis comparator, and an output end of the digital signal processor is connected with the control end of the switch module.
3. The current protection circuit of claim 2, wherein, The switch module comprises a positive current transistor and a negative current transistor, wherein, a control end of the positive current transistor is connected with a first output end of the digital signal processor, a first end of the positive current transistor is connected with the inverting input end of the positive current hysteresis comparator, and a second end of the positive current transistor is connected with the ground; a control end of the negative current transistor is connected with a second output end of the digital signal processor, a first end of the negative current transistor is connected with the inverting input end of the negative current hysteresis comparator, and a second end of the negative current transistor is connected with the ground.
4. The current protection circuit of claim 1, wherein, The circuit further comprises a reverse module and a driving module, wherein, an input end of the reverse module is connected with the output end of the hysteresis comparison module, and an output end of the reverse module is connected with an enable end of the driving module.
5. The current protection circuit of claim 4, wherein, The reverse module comprises a positive current diode, a negative current diode and an overcurrent comparator, wherein, a cathode of the positive current diode is connected with the output end of the positive current hysteresis comparator, and an anode of the positive current diode is connected with an inverting input end of the overcurrent comparator; a cathode of the negative current diode is connected with the output end of the negative current hysteresis comparator, and an anode of the negative current diode is connected with the inverting input end of the overcurrent comparator; a non-inverting input end of the overcurrent comparator is connected with the reference voltage, and an output end of the overcurrent comparator is connected with the enable end of the driving module.
6. The current protection circuit of claim 5, wherein, The driving module comprises a buffer and a driving chip, wherein, the enable end of the buffer and the enable end of the driving chip are both connected with the output end of the overcurrent comparator, an output end of the buffer is connected with an input end of the driving chip, and an output end of the driving chip is connected with a switch tube.
7. A battery, characterized by The battery comprises the current protection circuit according to any one of claims 1-6.
8. A machine device, characterized by The machine device comprises the battery according to claim 7.