Over-voltage and under-voltage protection circuit

Abstract

This application discloses an over- and under-voltage protection circuit. The over- and under-voltage protection circuit includes: a sampling module that steps down the sampled first voltage to a second voltage and then outputs it to a processing module; a power supply module that steps down the first voltage to a third voltage and then outputs it to a first step-down module; the first step-down module that steps down the third voltage to obtain a first comparison voltage and a second comparison voltage and outputs them to the processing module. The processing module disconnects the driving module to disconnect the execution module when the second voltage is greater than the first comparison voltage; disconnects the driving module to disconnect the execution module when the second voltage is less than the second comparison voltage; and turns on the driving module to turn on the execution module when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage. In the embodiments of this application, when the operating voltage of an external electrical device is too high or too low, the connection between the external electrical device and the external power supply device is disconnected to achieve the effect of protecting the external electrical device.

Description

Technical Field

[0001] The present application relates to the technical field of power supply control circuits, and particularly relates to an over-voltage and under-voltage protection circuit. Background Art

[0002] Currently, AC power supplies are widely used in various fields to supply power to electrical equipment (loads) in each field, enabling the electrical equipment to operate normally. However, in the prior art, there are still the following technical problems: When the electrical equipment is connected to the AC power supply and operates normally, over-voltage or under-voltage may occur due to various reasons, thus greatly affecting the operation of the electrical equipment. For example, in the fields of industrial control, motor protection, etc., when the voltage is under-voltage, that is, when the operating voltage of the electrical equipment is lower than the preset operating voltage of the electrical equipment, it will damage the electrical equipment. When the voltage is over-voltage, that is, when the operating voltage of the electrical equipment is higher than the preset operating voltage of the electrical equipment, it will also damage the electrical equipment. Summary of the Invention

[0003] In view of the above problems, the present application provides an over-voltage and under-voltage protection circuit. When the operating voltage of an external electrical equipment is detected to be too high or too low, the execution module can be disconnected, thereby disconnecting the connection between the external electrical equipment and the external power supply equipment, so as to achieve the effect of protecting the external electrical equipment when the operating voltage of the external electrical equipment is too high or too low.

[0004] On the one hand, the present application provides an over-voltage and under-voltage protection circuit, including: an acquisition module, a power supply module, a first step-down module, a processing module, a driving module, and an execution module. The acquisition module steps down the first voltage transmitted from the external electrical equipment to the acquisition module to a second voltage and then outputs it to the processing module. The power supply module steps down the first voltage transmitted from the external electrical equipment to the power supply module to a third voltage and then outputs it to the first step-down module. The first step-down module steps down the third voltage to obtain a first comparison voltage and a second comparison voltage, and outputs the first comparison voltage and the second comparison voltage to the processing module; wherein, the first comparison voltage is greater than the second comparison voltage. The processing module disconnects the driving module to make the execution module disconnect when the second voltage is greater than the first comparison voltage; disconnects the driving module to make the execution module disconnect when the second voltage is less than the second comparison voltage; and makes the driving module conduct to make the execution module conduct when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage.

[0005] In the technical solution of the embodiment of the present application, when it is detected that the operating voltage of the external electrical device, i.e., the first voltage, is too high (such as overvoltage) or too low (zero voltage, negative voltage, undervoltage, etc.), the driving module can be disconnected, so as to disconnect the connection between the external electrical device and the external power supply device, thereby achieving the effect of protecting the external electrical device. After disconnecting the connection between the external electrical device and the external power supply device, the connection between the external electrical device and the external power supply device can be automatically conducted when the operating voltage of the external electrical device is normal, so that the external electrical device can work normally. In this embodiment, the circuit structure is relatively simple, the cost is low, and it is easy to promote and use.

[0006] In some embodiments, the power supply module includes: a rectifier, a filter, a voltage regulator, a first resistor, and a second resistor. The two input terminals of the rectifier are respectively used to connect to the live wire and the neutral wire, and the two output terminals of the rectifier are respectively electrically connected to the positive electrode and the negative electrode of the filter. The first resistor and the second resistor are connected in series as a group and are connected in parallel with the filter. The voltage regulator is used to stabilize the voltage of the positive electrode of the filter at according to the size ratio of the first resistor and the second resistor, so as to output the third voltage to the first buck module through the positive electrode of the filter.

[0007] In this embodiment, the rectifier converts the alternating current into a direct current signal; and the filter is used for filtering. The voltage of the positive electrode of the filter can also be stabilized at the above-mentioned third voltage through the action of the first resistor, the second resistor, and the voltage regulator, so as to provide a relatively stable third voltage to the first buck module.

[0008] In some embodiments, the rectifier includes a first double diode and a second double diode, and the over- and under-voltage protection circuit further includes a varistor, a buck resistor, and a buck capacitor. The buck resistor and the buck capacitor are connected in series between the input terminal of the varistor and the input terminal of the first double diode, and the two output terminals of the first double diode are respectively electrically connected to the negative electrode and the positive electrode of the filter. The output terminal of the varistor is electrically connected to the input terminal of the second double diode, and the two output terminals of the second double diode are respectively electrically connected to the negative electrode and the positive electrode of the filter.

[0009] In the embodiment of the present application, the rectifying function is realized by the first double diode and the second double diode. The energy is absorbed through the action of the varistor to protect the subsequent circuit of the varistor against surges. The first voltage is stepped down through the buck resistor and the buck capacitor, and the stepped-down first voltage is output to the power supply module, so that the power supply module steps down the above-mentioned stepped-down first voltage to the third voltage and then outputs it to the first buck module.

[0010] In some embodiments, the processing module includes a first comparator and a second comparator. The first output terminal of the first buck module is electrically connected to the positive input terminal of the first comparator, and the second output terminal of the first buck module is electrically connected to the positive input terminal of the second comparator. The negative input terminals of the first comparator and the second comparator are respectively electrically connected to the acquisition module, such that: when the second voltage is greater than the first comparison voltage, the first comparison voltage is less than the voltage at the negative input terminal of the first comparator, the output terminal of the first comparator outputs a low level, and the second comparison voltage is less than the voltage at the negative input terminal of the second comparator, the output terminal of the second comparator outputs a low level, so as to disconnect the driving module; when the second voltage is less than the second comparison voltage, the first comparison voltage is greater than the voltage at the negative input terminal of the first comparator, the output terminal of the first comparator outputs a high level, and the second comparison voltage is greater than the voltage at the negative input terminal of the second comparator, the output terminal of the second comparator outputs a high level, so as to disconnect the driving module; when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage, the first comparison voltage is greater than the voltage at the negative input terminal of the first comparator, the output terminal of the first comparator outputs a high level, and the second comparison voltage is less than the voltage at the negative input terminal of the second comparator, the output terminal of the second comparator outputs a low level, so as to turn on the driving module.

[0011] In this embodiment, the magnitude relationship between the first comparison voltage at the positive input terminal of the first comparator and the second voltage at the negative input terminal of the first comparator can be used to make the output terminal of the first comparator output a high level or a low level. The magnitude relationship between the second comparison voltage at the positive input terminal of the second comparator and the second voltage at the negative input terminal of the second comparator is used to make the output terminal of the second comparator output a high level or a low level. Thus, the driving module is disconnected or turned on according to the level relationship output by the first comparator and the second comparator. And the first buck module can be used to make the above-mentioned first comparison voltage and the above-mentioned second comparison voltage different, so as to further improve the feasibility of the technical solution of the present application.

[0012] In some embodiments, the driving module includes a first diode, the execution module is a coil, and the over-voltage and under-voltage protection circuit further includes an RC filtering module. The RC filtering module includes a first capacitor and a third resistor. The positive electrode of the first diode is electrically connected to the output terminal of the first comparator. The negative electrode of the first diode is electrically connected to one end of the coil, and the other end of the coil is electrically connected to the output terminal of the second comparator. The first capacitor is connected in parallel with the coil, and the negative electrode of the first capacitor is electrically connected to the end where the coil is electrically connected to the output terminal of the second comparator. One end of the third resistor is electrically connected to the negative electrode of the first diode, and the other end is electrically connected to the end of the first capacitor that is not electrically connected to the output terminal of the second comparator.

[0013] In this embodiment, since the first diode has a one-way conduction effect, the on or off state of the first diode can be determined by the voltage relationship across the two ends of the first diode. That is, in this embodiment, the on or off state of the first diode can be determined by the magnitudes of the voltages output from the output terminal of the first comparator and the output terminal of the second comparator. For example, when the first comparator outputs a high level and the second comparator outputs a high level, the first diode is turned off, i.e., disconnected. When the first comparator outputs a low level and the second comparator outputs a low level, the first diode is turned off, i.e., disconnected. When the first comparator outputs a high level and the second comparator outputs a low level, the positive electrode of the first diode is at a high level and the negative electrode is at a low level, causing the first diode to conduct. Additionally, the voltage output by the first diode can be filtered by the first capacitor and the third resistor, so that the subsequent circuit of the first capacitor and the third resistor can obtain a relatively smooth DC voltage, which can further improve the reliability of the execution module to work properly.

[0014] In some embodiments, the first buck module includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor. The fourth resistor and the fifth resistor are connected in parallel to form a group A resistor, and the sixth resistor and the seventh resistor are connected in parallel to form a group B resistor. The input terminal of the group A resistor is electrically connected to the positive electrode of the filter so that the input voltage of the group A resistor is the third voltage. The output terminals are respectively electrically connected to the input terminal of the eighth resistor and the positive input terminal of the first comparator. The output terminal of the eighth resistor is respectively electrically connected to the input terminal of the group B resistor and the positive input terminal of the second comparator. The output terminal of the group B resistor is grounded.

[0015] In this embodiment, the above-mentioned buck effect can be achieved through the functions of the fourth resistor, the fifth resistor, the sixth resistor, the seventh resistor, and the eighth resistor to provide the first comparison voltage at the positive input terminal of the first comparator and the second comparison voltage at the positive input terminal of the second comparator.

[0016] In some embodiments, the over-voltage and under-voltage protection circuit further includes: a ninth resistor and a tenth resistor. One end of the ninth resistor is electrically connected to the positive input terminal of the first comparator, and the other end is electrically connected to the output terminal of the first comparator. One end of the tenth resistor is electrically connected to the positive input terminal of the second comparator, and the other end is electrically connected to the output terminal of the second comparator.

[0017] The ninth resistor in this embodiment can protect the first comparator from being damaged due to exceeding the withstand voltage value. The tenth resistor in this embodiment can protect the second comparator from being damaged due to exceeding the withstand voltage value.

[0018] In some embodiments, the acquisition module includes a rectifier diode and a second buck module. The rectifier diode rectifies the first voltage transmitted to the acquisition module, and the second buck module steps down the rectified first voltage to obtain the second voltage.

[0019] In this embodiment, half-wave rectification can be performed through a rectifier diode, and the second voltage can be obtained by stepping down through the second voltage reduction module. The second voltage is respectively used to compare with the first comparison voltage and the second comparison voltage. The solution of this embodiment can enable the acquisition module to provide a relatively stable second voltage to the processing module.

[0020] In some embodiments, the second voltage reduction module includes: an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor. The eleventh resistor, the twelfth resistor, and the thirteenth resistor are connected in series in sequence, and the input end of the eleventh resistor is electrically connected to the negative electrode of the rectifier diode. The output end of the thirteenth resistor is respectively electrically connected to the negative input end of the first comparator and the negative input end of the second comparator. One end of the fourteenth resistor is electrically connected to the output end of the thirteenth resistor, and the other end is grounded.

[0021] In this embodiment, the magnitude of the second voltage transmitted to the negative input end of the first comparator and the negative input end of the second comparator is determined by the magnitude relationship of the eleventh resistor, the twelfth resistor, the thirteenth resistor, and the fourteenth resistor.

[0022] In some embodiments, the over-voltage and under-voltage protection circuit further includes a second diode; and the positive electrode of the second diode is electrically connected to the output end of the thirteenth resistor, and the negative electrode is electrically connected to the negative input end of the first comparator and the negative input end of the second comparator. The second diode in this embodiment has a one-way conduction function, which can avoid damage to the components in the subsequent circuit when the external electrical device is reversely connected.

[0023] And / or, the over-voltage and under-voltage protection circuit further includes a fifteenth resistor and a second capacitor; and one end of the fifteenth resistor is respectively electrically connected to the negative input end of the first comparator and the negative input end of the second comparator, and the other end is grounded to pull up the voltage of the negative input end of the first comparator and the negative input end of the second comparator. The second capacitor is connected in parallel with the fifteenth resistor. In this embodiment, the fifteenth resistor and the second capacitor have a filtering function, and at the same time can provide a pull-up voltage for the negative input end of the first comparator and the negative input end of the second comparator to improve the reliability of the normal operation of the first comparator and the second comparator.

[0024] In a second aspect, this embodiment further provides an electrical device, including: the above external electrical device and the over-voltage and under-voltage protection circuit of any one of the above embodiments. The external electrical device is electrically connected to the acquisition module. When the execution module is disconnected, the connection between the external electrical device and the external power supply device is disconnected. When the execution module is turned on, the connection between the external electrical device and the external power supply device is turned on.

[0025] In this embodiment, since the electrical device includes the over-voltage and under-voltage protection circuit of any one of the above embodiments, this embodiment can disconnect the driving module when it detects that the operating voltage of the external electrical device, i.e., the first voltage, is too high (such as over-voltage) or too low (such as zero voltage, negative voltage or under-voltage, etc.), thereby disconnecting the connection between the external electrical device and the external power supply device to achieve the effect of protecting the external electrical device. After disconnecting the connection between the external electrical device and the external power supply device, it can also automatically conduct the connection between the external electrical device and the external power supply device when the operating voltage of the external electrical device is normal, so that the external electrical device can work normally. The circuit structure in this embodiment is relatively simple, with low cost and is easy to promote and use.

[0026] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the following specifically illustrates the specific implementation manners of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of this application. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0028] Figure 1 is a schematic structural diagram of the over-voltage and under-voltage protection circuit in some embodiments of this application;

[0029] Figure 2 is a schematic circuit diagram of the over-voltage and under-voltage protection circuit in some embodiments of this application.

[0030] The reference numerals in the specific embodiments are as follows:

[0031] 11 - Acquisition module; 12 - Power supply module; 13 - First step - down module; 14 - Processing module; 15 - Driving module, 16 - Execution module; RV1 - Varistor; VD1 - First double - diode; VD2 - Second double - diode; C1 - First filter capacitor; C2 - Second filter capacitor; R0 - Step - down resistor; C0 - Step - down capacitor; VD3 - First diode; Coil1 - Coil; C3 - First capacitor; IC1 - Voltage - stabilizing chip; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; IC2A - First comparator; IC2B - Second comparator; R4 - Fourth resistor; R5 - Fifth resistor; R6 - Sixth resistor; R7 - Seventh resistor; R8 - Eighth resistor; R9 - Ninth resistor; R10 - Tenth resistor; VD4 - Rectifier diode; R11 - Eleventh resistor; R12 - Twelfth resistor; R13 - Thirteenth resistor; R14 - Fourteenth resistor; VD5 - Second diode; R15 - Fifteenth resistor; C4 - Second capacitor. Detailed implementation manner

[0032] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above - mentioned drawings are intended to cover non - exclusive inclusion.

[0034] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary - secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality" means more than two unless otherwise specifically defined.

[0035] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0036] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the embodiments of the present application.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0038] The following embodiments further illustrate the solution of the present application:

[0039] Some embodiments of the present application disclose an over- and under-voltage protection circuit. Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the over- and under-voltage protection circuit in some embodiments of the present application. As Figure 1 shown, the over- and under-voltage protection circuit includes: an acquisition module 11, a power supply module 12, a first step-down module 13, a processing module 14, a driving module 15, and an execution module 16. The acquisition module 11 steps down the first voltage transmitted by the external electrical device to the acquisition module 11 to a second voltage and then outputs it to the processing module 14. The power supply module 12 steps down the first voltage transmitted by the external electrical device to the power supply module 12 to a third voltage and then outputs it to the first step-down module 13. The first step-down module 13 steps down the third voltage to obtain a first comparison voltage and a second comparison voltage, and outputs the first comparison voltage and the second comparison voltage to the processing module 14. Among them, the first comparison voltage is greater than the second comparison voltage. When the second voltage is greater than the first comparison voltage, the processing module 14 disconnects the driving module 15 to make the execution module 16 disconnect. When the second voltage is less than the second comparison voltage, the processing module 14 disconnects the driving module 15 to make the execution module 16 disconnect. When the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage, the processing module 14 turns on the driving module 15 to make the execution module 16 turn on.

[0040] It is worth mentioning that the values of the second voltage, the first comparison voltage, and the second comparison voltage can be set according to the type of the actual external electrical device and its operating voltage. This application does not limit the values of the second voltage, the first comparison voltage, and the second comparison voltage.

[0041] In actual applications, when the external electrical device needs to operate, it can be connected to an external power supply device. For example, the external power supply device can be an AC power supply. At this time, the first voltage transmitted by the external electrical device to the acquisition module 11 is the voltage of the AC power supply, which is a voltage that changes in real time. And due to the influence of factors such as the external environment, the first voltage not only changes in direction but also may change in magnitude.

[0042] Specifically, when the external electrical device is connected to the external power supply device, if the acquisition module 11 acquires that the operating voltage of the external electrical device, i.e., the above-mentioned first voltage, is too high and exceeds the load of the external electrical device (such as overvoltage), the second voltage after voltage reduction will be greater than the first comparison voltage VH, and at this time, the drive module 15 is disconnected. When the drive module 15 is disconnected, the release is not powered, and the product is in a tripped state and cannot be closed. At this time, the connection between the external electrical device and the external power supply device is disconnected and cannot conduct. The product can refer to a leakage circuit breaker or a switch, etc., and will not be listed here.

[0043] If the acquisition module 11 acquires that the operating voltage of the external electrical device, i.e., the above-mentioned first voltage, is too low (such as zero voltage, negative voltage, or undervoltage, undervoltage), the second voltage will be less than the second comparison voltage VL, and at this time, the drive module 15 is disconnected. When the drive module 15 is disconnected, the release is not powered, and the product is in a tripped state and cannot be closed. At this time, the connection between the external electrical device and the external power supply device is disconnected and cannot conduct.

[0044] If the acquisition module 11 acquires that the operating voltage of the external electrical device, i.e., the above-mentioned first voltage, is normal, the second voltage will be greater than or equal to the second comparison voltage VL and less than or equal to the first comparison voltage VH, and at this time, the drive module 15 is conducting. When the drive module 15 is conducting, the release is powered, and the product can be normally closed. At this time, the connection between the external electrical device and the external power supply device can conduct.

[0045] In summary, in the technical solution of this embodiment, when it is detected that the operating voltage of the external electrical device is too high, i.e., overvoltage, or too low, i.e., zero voltage, negative voltage, or undervoltage, the drive module 15 can be disconnected, thereby disconnecting the connection between the external electrical device and the external power supply device, so as to achieve the effect of protecting the external electrical device when the operating voltage of the external electrical device is too high or too low. And, in this embodiment, the circuit structure is relatively simple, the cost is low, and it is easy to promote and use.

[0046] Another embodiment of this application discloses an over- and under-voltage protection circuit. Please refer to Figure 2 ,Figure 2 This is the circuit schematic diagram of the over-voltage and under-voltage protection circuit in some embodiments of the present application. In addition to including the technical features of any of the above embodiments, this embodiment further includes the following technical features:

[0047] As Figure 1 and Figure 2 shown, the power supply module 12 includes: a rectifier, a filter, a voltage regulator, a first resistor R1, and a second resistor R2. The two input terminals of the rectifier are respectively used to connect to the live wire and the neutral wire, and the two output terminals of the rectifier are respectively electrically connected to the positive pole and the negative pole of the filter. The first resistor R1 and the second resistor R2 are connected in series as a group and are connected in parallel with the filter. The voltage regulator is used to stabilize the voltage of the positive pole of the filter at a certain value according to the size ratio of the first resistor R1 and the second resistor R2, so as to output a third voltage to the first buck module 13 through the positive pole of the filter. For example, the negative pole of the filter can be used to connect to the ground wire GND, and the positive pole of the filter is electrically connected to the first buck module 13. The rectifier converts the alternating current into a direct current signal; and the filter is used for filtering. The voltage of the positive pole of the filter can also be stabilized at the above-mentioned third voltage through the action of the first resistor R1, the second resistor R2, and the voltage regulator, so as to provide a relatively stable third voltage to the first buck module 13. For example, the voltage of the positive pole of the filter, i.e., V+ in the figure, can be stabilized at 8V, 9V, 10V, etc. according to the size ratio of the first resistor R1 and the second resistor R2, which will not be listed here.

[0048] The voltage regulator in this embodiment can be a voltage regulator chip IC1. Specifically, the first terminal of the voltage regulator is electrically connected to the positive pole of the filter, which can mean that the output terminal of the voltage regulator chip IC1 is electrically connected to the positive pole of the filter. The second terminal of the voltage regulator is grounded to GND, which can mean that the ground terminal or the input terminal of the voltage regulator chip IC1 is grounded to GND. The third terminal of the voltage regulator is electrically connected between the first resistor R1 and the second resistor R2, which can mean that the input terminal of the voltage regulator chip IC1 is connected between the first resistor R1 and the second resistor R2. When the current passing through the voltage regulator chip IC1 changes within a large range, the voltage across the voltage regulator chip IC1 is maintained balanced, so as to achieve the voltage regulation function, and the cost of the voltage regulator chip IC1 is relatively low, which can reduce the cost of the over-voltage and under-voltage protection circuit to a certain extent.

[0049] The rectifier includes a first double diode VD1 and a second double diode VD2. The over-voltage and under-voltage protection circuit further includes a varistor RV1, a buck resistor R0, and a buck capacitor C0. The buck resistor R0 and the buck capacitor C0 are connected in series between the input terminal of the varistor RV1 and the input terminal of the first double diode VD1. The two output terminals of the first double diode VD1 are respectively electrically connected to the negative pole and the positive pole of the filter. The output terminal of the varistor RV1 is electrically connected to the input terminal of the second double diode VD2, and the two output terminals of the second double diode VD2 are respectively electrically connected to the negative pole and the positive pole of the filter.

[0050] For example, the input terminal of the varistor RV1 is used to be electrically connected to the live wire L, and the output terminal of the varistor RV1 is used to be electrically connected to the neutral wire N. The step-down resistor R0 and the step-down capacitor C0 are connected in series. The input terminal of the step-down resistor R0 is used to connect to the live wire L, and the output terminal of the step-down capacitor C0 is electrically connected to the input terminal of the first double diode VD1. Alternatively, the input terminal of the step-down capacitor C0 is used to connect to the live wire L, and the output terminal of the step-down resistor R0 is electrically connected to the input terminal of the first double diode VD1.

[0051] The rectifying function is achieved through the first double diode VD1 and the second double diode VD2. The varistor RV1 absorbs energy to provide surge protection for the subsequent circuit of the varistor RV1. The step-down resistor R0 and the step-down capacitor C0 step down the first voltage and output the stepped-down first voltage to the power supply module 12, so that the power supply module 12 further steps down the stepped-down first voltage to a third voltage and then outputs it to the first step-down module 13.

[0052] In addition, the first double diode VD1 includes two diodes connected in series; the input terminal of the varistor RV1 is electrically connected to the input terminal of the first double diode VD1, where the input terminal of the first double diode VD1 is between the two diodes connected in series. The two output terminals of the first double diode VD1 include a positive output terminal and a negative output terminal. The positive output terminal of the first double diode VD1 is grounded to the ground wire GND, and the negative output terminal of the first double diode VD1 is electrically connected to the positive pole of the above filter. The second double diode VD2 includes two diodes connected in series; the output terminal of the varistor RV1 is electrically connected to the input terminal of the second double diode VD2, where the input terminal of the second double diode VD2 is between the two diodes connected in series. The two output terminals of the second double diode VD2 include a positive output terminal and a negative output terminal. The positive output terminal of the second double diode VD2 is grounded to the ground wire GND, and the negative output terminal of the second double diode VD2 is electrically connected to the positive pole of the above filter.

[0053] The filter may include a first filter capacitor C1. The positive pole of the first filter capacitor C1 is electrically connected to the positive pole of the above filter, and the negative pole is grounded to the ground wire GND for filtering. The filter may further include a second filter capacitor C2, and the second filter capacitor C2 may be an ordinary capacitor without positive and negative polarities. One end of the second filter capacitor C2 is electrically connected to the positive pole of the filter, and the other end is electrically connected to the ground wire GND for further filtering to improve the filtering effect.

[0054] In the actual circuit design process, the processing module 14 includes a first comparator IC2A and a second comparator IC2B. The first output terminal of the first buck module 13 is electrically connected to the positive input terminal of the first comparator IC2A, and the second output terminal of the first buck module 13 is electrically connected to the positive input terminal of the second comparator IC2B. The negative input terminals of the first comparator IC2A and the second comparator IC2B are respectively electrically connected to the acquisition module 11, such that: when the second voltage is greater than the first comparison voltage, the first comparison voltage is less than the voltage at the negative input terminal of the first comparator IC2A, the output terminal of the first comparator IC2A outputs a low level, and the second comparison voltage is less than the voltage at the negative input terminal of the second comparator IC2B, the output terminal of the second comparator IC2B outputs a low level, so as to disconnect the driving module 15; when the second voltage is less than the second comparison voltage, the first comparison voltage is greater than the voltage at the negative input terminal of the first comparator IC2A, the output terminal of the first comparator IC2A outputs a high level, and the second comparison voltage is greater than the voltage at the negative input terminal of the second comparator IC2B, the output terminal of the second comparator IC2B outputs a high level, so as to disconnect the driving module 15; when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage, the first comparison voltage is greater than the voltage at the negative input terminal of the first comparator IC2A, the output terminal of the first comparator IC2A outputs a high level, and the second comparison voltage is less than the voltage at the negative input terminal of the second comparator IC2B, the output terminal of the second comparator IC2B outputs a low level, so as to turn on the driving module 15.

[0055] In this embodiment, the magnitude relationship between the first comparison voltage at the positive input terminal of the first comparator IC2A and the second voltage at the negative input terminal of the first comparator IC2A can be used to make the output terminal of the first comparator IC2A output a high level or a low level. The magnitude relationship between the second comparison voltage at the positive input terminal of the second comparator IC2B and the second voltage at the negative input terminal of the second comparator IC2B is used to make the output terminal of the second comparator IC2B output a high level or a low level. Thus, the driving module 15 is disconnected or turned on according to the level relationship output by the first comparator IC2A and the second comparator IC2B. And the first buck module 13 can be used to make the above-mentioned first comparison voltage and the above-mentioned second comparison voltage different, so as to further improve the feasibility of the technical solution of the present application.

[0056] The above-mentioned driving module 15 includes a first diode VD3, and the execution module 16 is a coil Coil1. The over-voltage and under-voltage protection circuit further includes an RC filtering module, and the RC filtering module includes a first capacitor C3 and a third resistor R3. The positive electrode of the first diode VD3 is electrically connected to the output terminal of the first comparator IC2A. The negative electrode of the first diode VD3 is electrically connected to one end of the coil Coil1, and the other end of the coil Coil1 is electrically connected to the output terminal of the second comparator IC2B. The first capacitor C3 is connected in parallel with the coil Coil1, and the negative electrode of the first capacitor C3 is electrically connected to the end of the coil Coil1 that is electrically connected to the output terminal of the second comparator IC2B. One end of the third resistor R3 is electrically connected to the negative electrode of the first diode VD3, and the other end is electrically connected to the end of the first capacitor C3 that is not electrically connected to the output terminal of the second comparator IC2B. The voltage output by the first diode VD3 is filtered by the first capacitor C3 and the third resistor R3, so that a relatively smooth DC voltage can be obtained by the subsequent circuit of the first capacitor C3 and the third resistor R3, which can further improve the reliability of the normal operation of the execution module 16.

[0057] In this embodiment, since the first diode VD3 has a one-way conduction function, the first diode VD3 can be made to be in a conducting or non-conducting state by the magnitude relationship of the voltages across the two ends of the first diode VD3. That is, in this embodiment, the first diode VD3 can be made to be in a conducting or non-conducting state by the magnitudes of the voltages output by the output terminal of the first comparator IC2A and the output terminal of the second comparator IC2B. For example, when the first comparator IC2A outputs a high level and the second comparator IC2B outputs a high level, the first diode VD3 is made to be non-conducting, that is, disconnected. When the first comparator IC2A outputs a low level and the second comparator IC2B outputs a low level, the first diode VD3 is made to be non-conducting, that is, disconnected. When the first comparator IC2A outputs a high level and the second comparator IC2B outputs a low level, the positive electrode of the first diode VD3 is at a high level and the negative electrode is at a low level, making the first diode VD3 conducting. When the first diode VD3 is conducting, the coil Coil1 is conducting to conduct the connection between the external electrical device and the external power supply device. When the first diode VD3 is disconnected, the coil Coil1 is disconnected to disconnect the connection between the external electrical device and the external power supply device. The cost of the coil Coil1 is relatively low and the working mode is relatively reliable, which can reduce the cost of the over-voltage and under-voltage protection circuit to a certain extent and improve the reliability of the voltage protection circuit.

[0058] It is worth mentioning that the first step-down module 13 includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The fourth resistor R4 and the fifth resistor R5 are connected in parallel to form a group A resistor, and the sixth resistor R6 and the seventh resistor R7 are connected in parallel to form a group B resistor. The input end of the group A resistor is electrically connected to the positive electrode of the filter so that the input end voltage of the group A resistor is the third voltage. The output ends are respectively electrically connected to the input end of the eighth resistor R8 and the positive input end of the first comparator IC2A. The output end of the eighth resistor R8 is respectively electrically connected to the input end of the group B resistor and the positive input end of the second comparator IC2B. The output end of the group B resistor is grounded. The above step-down effect can be achieved through the functions of the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8 to provide the first comparison voltage at the positive input end of the first comparator IC2A and the second comparison voltage at the positive input end of the second comparator IC2B.

[0059] In addition, the over-voltage and under-voltage protection circuit further includes: a ninth resistor R9 and a tenth resistor R10. One end of the ninth resistor R9 is electrically connected to the positive input end of the first comparator IC2A, and the other end is electrically connected to the output end of the first comparator IC2A. One end of the tenth resistor R10 is electrically connected to the positive input end of the second comparator IC2B, and the other end is electrically connected to the output end of the second comparator IC2B. The ninth resistor R9 in this embodiment can protect the first comparator IC2A to prevent the first comparator IC2A from being damaged due to exceeding the withstand voltage value. The tenth resistor R10 in this embodiment can protect the second comparator IC2B to prevent the second comparator IC2B from being damaged due to exceeding the withstand voltage value.

[0060] Optionally, the acquisition module 11 includes a rectifier diode VD4 and a second step-down module. The rectifier diode VD4 rectifies the first voltage transmitted to the acquisition module 11, and the second step-down module steps down the rectified first voltage to obtain a second voltage. In this embodiment, half-wave rectification can be performed by the rectifier diode VD4, and the second voltage can be obtained by stepping down by the second step-down module. The second voltage is respectively used to compare with the above first comparison voltage and the second comparison voltage. The solution of this embodiment can enable the acquisition module 11 to provide a relatively stable second voltage to the processing module 14.

[0061] Specifically, the second step-down module includes: the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, and the fourteenth resistor R14. The eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13 are connected in series in sequence, and the input end of the eleventh resistor R11 is electrically connected to the negative electrode of the rectifier diode VD4. The output end of the thirteenth resistor R13 is electrically connected to the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B respectively. One end of the fourteenth resistor R14 is electrically connected to the output end of the thirteenth resistor R13, and the other end is grounded.

[0062] In this embodiment, the magnitude relationship of the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, and the fourteenth resistor R14 is used to determine the magnitude of the second voltage transmitted to the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B.

[0063] The over-voltage and under-voltage protection circuit in this application further includes a second diode VD5; and the positive electrode of the second diode VD5 is electrically connected to the output end of the thirteenth resistor R13, and the negative electrode is electrically connected to the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B. The second diode VD5 in this embodiment has a one-way conduction function, which can prevent the components in the subsequent circuit from being damaged when the external electrical equipment is reversely connected.

[0064] In the actual circuit design process, the over-voltage and under-voltage protection circuit further includes a fifteenth resistor R15 and a second capacitor C4; and one end of the fifteenth resistor R15 is electrically connected to the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B respectively, and the other end is grounded to pull up the voltage of the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B. The second capacitor C4 is connected in parallel with the fifteenth resistor R15. In this embodiment, the fifteenth resistor R15 and the second capacitor C4 have a filtering function, and at the same time, they can provide a pull-up voltage for the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B to improve the reliability of the normal operation of the first comparator IC2A and the second comparator IC2B.

[0065] This application further includes a third capacitor C5. One end of the third capacitor C5 is electrically connected to the positive electrode of the above-mentioned filter, and the other end is grounded to GND. The third capacitor C5 in this embodiment can filter and provide a smooth voltage for the subsequent circuit of the first comparator IC2A and the second comparator IC2B.

[0066] The following combines Figure 2 to further illustrate the working principle of this embodiment:

[0067] The over-voltage and under-voltage protection circuit of the present application can be used in external electrical equipment, which generally refers to a load in the art. For example, in the present application, when the coil Coil1 in the over-voltage and under-voltage protection circuit is disconnected, the connection between the external electrical equipment and the external power supply equipment is disconnected. Or in another embodiment, when the coil Coil1 in the voltage protection circuit is turned on, the connection between the external electrical equipment and the external power supply equipment is turned on.

[0068] For example: The external electrical equipment can be connected to the live wire L and the neutral wire N of the alternating current through the cooperation of a switch or a plug and a socket, etc. The present application does not limit the magnitude of the alternating current, which can be 230V or 220V, etc. In actual applications, it can be determined according to the working voltage when the external electrical equipment works normally. When the external electrical equipment is connected to the live wire L and the neutral wire N of the alternating current, the over-voltage and under-voltage protection circuit is also connected to the live wire L and the neutral wire N of the above alternating current through the first pin J1 and the second pin J2.

[0069] In summary, when the first voltage sampled by the sampling module is over-voltage or zero voltage, negative voltage or loss of voltage, the coil Coil1 is disconnected. When the first voltage sampled by the sampling module is the voltage required for the operation of the external electrical equipment, the coil Coil1 is turned on.

[0070] Since the connection between the external electrical equipment and the external power supply equipment is turned on when the coil Coil1 is closed. The connection between the external electrical equipment and the external power supply equipment is disconnected when the coil Coil1 is disconnected. Therefore, in this embodiment, the over-voltage and under-voltage protection circuit can be used to disconnect the driving module 15 when it is detected that the working voltage of the external electrical equipment is too high, i.e., over-voltage, or too low, i.e., zero voltage, negative voltage or under-voltage, so as to disconnect the connection between the external electrical equipment and the external power supply equipment, and achieve the effect of protecting the external electrical equipment when the working voltage of the external electrical equipment is too high or too low. Moreover, the circuit structure in this embodiment is relatively simple, has a low cost, and is easy to promote and use.

[0071] Another embodiment of the present application discloses an electrical device, which further provides an electrical device including: the above-mentioned external electrical equipment and the over-voltage and under-voltage protection circuit of any one of the above embodiments. The external electrical equipment is electrically connected to the acquisition module. When the execution module is disconnected, the connection between the external electrical equipment and the external power supply equipment is disconnected. When the execution module is turned on, the connection between the external electrical equipment and the external power supply equipment is turned on.

[0072] In this embodiment, since the electrical device includes the over-voltage and under-voltage protection circuit of any one of the above embodiments, this embodiment can use the above over-voltage and under-voltage protection circuit to disconnect the driving module when it detects that the operating voltage of the external electrical device, i.e., the first voltage, is not within the preset voltage range, thereby disconnecting the connection between the external electrical device and the external power supply device, so as to achieve the effect of protecting the external electrical device when the operating voltage of the external electrical device is not within the preset voltage range. This embodiment can also automatically conduct the connection between the external electrical device and the external power supply device when the operating voltage of the external electrical device is within the preset voltage range, so that the external electrical device can work normally. Moreover, the circuit structure in this embodiment is relatively simple, with low cost and easy to promote and use. Additionally, in actual applications, not being within the preset voltage range can be overvoltage, which is greater than the maximum value in the preset voltage range. Or, it can also be undervoltage, negative voltage, or any positive voltage less than the minimum value in the preset voltage range, etc., and will not be listed here.

[0073] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. An over- and under-voltage protection circuit, characterized in that, Including: A collection module, a power module, a first step-down module, a processing module, a driving module, and an execution module; The collection module steps down the first voltage transmitted by the external electrical device to the collection module to a second voltage and then outputs it to the processing module; The power module steps down the first voltage transmitted by the external electrical device to the power module to a third voltage and then outputs it to the first step-down module; The first step-down module steps down the third voltage to obtain a first comparison voltage and a second comparison voltage, and outputs the first comparison voltage and the second comparison voltage to the processing module; wherein, the first comparison voltage is greater than the second comparison voltage; When the second voltage is greater than the first comparison voltage, the processing module disconnects the driving module to disconnect the execution module; when the second voltage is less than the second comparison voltage, the processing module disconnects the driving module to disconnect the execution module; when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage, the processing module turns on the driving module to turn on the execution module; The driving module includes a first diode, the execution module is a coil, the over-voltage and under-voltage protection circuit further includes an RC filtering module, and the RC filtering module includes a first capacitor and a third resistor; The positive electrode of the first diode is electrically connected to the output terminal of the first comparator; The negative electrode of the first diode is electrically connected to one end of the coil, and the other end of the coil is electrically connected to the output terminal of the second comparator; The first capacitor is connected in parallel with the coil, and the negative electrode of the first capacitor is electrically connected to the end where the coil is electrically connected to the output terminal of the second comparator; One end of the third resistor is electrically connected to the negative electrode of the first diode, and the other end is electrically connected to the end of the first capacitor that is not electrically connected to the output terminal of the second comparator; The first step-down module includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor; The fourth resistor and the fifth resistor are connected in parallel to form a group of A resistors, and the sixth resistor and the seventh resistor are connected in parallel to form a group of B resistors; The input terminal of the group of A resistors is electrically connected to the positive electrode of the filter so that the input terminal voltage of the group of A resistors is the third voltage, the output terminals are respectively electrically connected to the input terminal of the eighth resistor and the positive input terminal of the first comparator, the output terminal of the eighth resistor is respectively electrically connected to the input terminal of the group of B resistors and the positive input terminal of the second comparator, and the output terminal of the group of B resistors is grounded.

2. The over-voltage and under-voltage protection circuit according to claim 1, wherein The power module includes: a rectifier, a filter, a voltage regulator, a first resistor, and a second resistor; The two input terminals of the rectifier are respectively used to connect to the live wire and the neutral wire, and the two output terminals of the rectifier are respectively electrically connected to the positive electrode and the negative electrode of the filter; The first resistor and the second resistor are connected in series to form a group and then connected in parallel with the filter; The voltage regulator is used to stabilize the voltage of the positive electrode of the filter at the third voltage according to the magnitude ratio of the first resistor and the second resistor, so as to output the third voltage to the first step-down module through the positive electrode of the filter.

3. The over-voltage and under-voltage protection circuit according to claim 2, characterized in that, The rectifier includes a first double diode and a second double diode, and the over-voltage and under-voltage protection circuit further includes a varistor, a step-down resistor and a step-down capacitor; The step-down resistor and the step-down capacitor are connected in series between the input end of the varistor and the input end of the first double diode, and the two output ends of the first double diode are respectively electrically connected to the negative electrode and the positive electrode of the filter; The output end of the varistor is electrically connected to the input end of the second double diode, and the two output ends of the second double diode are respectively electrically connected to the negative electrode and the positive electrode of the filter.

4. The over-voltage and under-voltage protection circuit according to claim 2 or 3, characterized in that, The processing module includes a first comparator and a second comparator; The first output end of the first step-down module is electrically connected to the positive input end of the first comparator, the second output end of the first step-down module is electrically connected to the positive input end of the second comparator, and the negative input ends of the first comparator and the second comparator are respectively electrically connected to the acquisition module, such that: When the second voltage is greater than the first comparison voltage, the first comparison voltage is less than the voltage of the negative input end of the first comparator, the output end of the first comparator outputs a low level, and the second comparison voltage is less than the voltage of the negative input end of the second comparator, the output end of the second comparator outputs a low level, so as to disconnect the driving module; When the second voltage is less than the second comparison voltage, the first comparison voltage is greater than the voltage of the negative input end of the first comparator, the output end of the first comparator outputs a high level, and the second comparison voltage is greater than the voltage of the negative input end of the second comparator, the output end of the second comparator outputs a high level, so as to disconnect the driving module; When the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage, the first comparison voltage is greater than the voltage of the negative input end of the first comparator, the output end of the first comparator outputs a high level, and the second comparison voltage is less than the voltage of the negative input end of the second comparator, the output end of the second comparator outputs a low level, so as to turn on the driving module.

5. The over-voltage and under-voltage protection circuit according to claim 4, characterized in that, The over-voltage and under-voltage protection circuit further includes: a ninth resistor and a tenth resistor; One end of the ninth resistor is electrically connected to the positive input end of the first comparator, and the other end is electrically connected to the output end of the first comparator; One end of the tenth resistor is electrically connected to the positive input end of the second comparator, and the other end is electrically connected to the output end of the second comparator.

6. The over- and under-voltage protection circuit according to claim 4, characterized in that, The acquisition module includes a rectifier diode and a second step-down module; The rectifier diode rectifies the first voltage transmitted to the acquisition module, and the second step-down module steps down the rectified first voltage to obtain the second voltage.

7. The over- and under-voltage protection circuit according to claim 6, characterized in that, The second step-down module includes: an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor; The eleventh resistor, the twelfth resistor, and the thirteenth resistor are connected in series in sequence, and the input end of the eleventh resistor is electrically connected to the negative electrode of the rectifier diode, and the output end of the thirteenth resistor is respectively electrically connected to the negative input end of the first comparator and the negative input end of the second comparator; One end of the fourteenth resistor is electrically connected to the output end of the thirteenth resistor, and the other end is grounded.

8. The over-voltage and under-voltage protection circuit according to claim 7, wherein, The over-voltage and under-voltage protection circuit further includes a second diode; and The positive electrode of the second diode is electrically connected to the output end of the thirteenth resistor, and the negative electrode is electrically connected to the negative input end of the first comparator and the negative input end of the second comparator; and / or The over-voltage and under-voltage protection circuit further includes a fifteenth resistor and a second capacitor; and One end of the fifteenth resistor is respectively electrically connected to the negative input end of the first comparator and the negative input end of the second comparator, and the other end is grounded to pull up the voltages of the negative input end of the first comparator and the negative input end of the second comparator, and the second capacitor is connected in parallel with the fifteenth resistor.

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