CN114301030A

CN114301030A - Over-voltage and under-voltage protection circuit

Info

Publication number: CN114301030A
Application number: CN202111657833.1A
Authority: CN
Inventors: 陈琦琪; 徐泳健
Original assignee: Delixi Electric Co Ltd
Current assignee: Delixi Electric Co Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-08

Abstract

The application discloses cross undervoltage protection circuit. The overvoltage and undervoltage protection circuit comprises: the acquisition module is used for reducing the acquired first voltage to a second voltage and then outputting the second voltage to the processing module; the power supply module reduces the first voltage to a third voltage and outputs the third voltage to the first voltage reduction module; and the first voltage reduction module is used for reducing the third voltage to obtain a first comparison voltage and a second comparison voltage and outputting the first comparison voltage and the second comparison voltage to the processing module. The processing module enables the driving module to be disconnected when the second voltage is larger than the first comparison voltage so as to enable the execution module to be disconnected; when the second voltage is smaller than the second comparison voltage, the driving module is switched off so as to switch off the execution module; and 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 driving module is conducted to conduct the execution module. In the embodiment of the application, when the working voltage of the external electric equipment is higher or lower, the connection between the external electric equipment and the external power supply equipment is disconnected, so that the effect of protecting the external electric equipment is achieved.

Description

Over-voltage and under-voltage protection circuit

Technical Field

The application relates to the technical field of power supply control circuits, in particular to an over-voltage and under-voltage protection circuit.

Background

At present, an alternating current power supply is widely applied to various fields and supplies power to electric equipment, namely loads, in various fields so as to enable the electric equipment to work normally. However, the prior art has the following technical problems: when the electric equipment and the alternating current power supply are conducted to work normally, overvoltage or undervoltage and the like can occur due to various reasons, so that the operation of the electric equipment is greatly influenced. For example, in the fields of industrial control and motor protection, when the working voltage of the electric equipment is lower than the preset working voltage of the electric equipment, the electric equipment is damaged. In the event of an overvoltage, i.e. when the operating voltage of the consumer is higher than the preset operating voltage of the consumer, damage can also be caused to the consumer.

Disclosure of Invention

In view of the above problems, the present application provides an overvoltage and undervoltage protection circuit, which can disconnect an execution module when detecting that an operating voltage of an external electrical device is higher or lower, so as to disconnect the external electrical device from an external power supply device, so as to achieve an effect of protecting the external electrical device when the operating voltage of the external electrical device is higher or lower.

In one aspect, the present application provides an over-voltage and under-voltage protection circuit, including: the device comprises an acquisition module, a power supply module, a first voltage reduction module, a processing module, a driving module and an execution module. And the acquisition module is used for reducing the first voltage transmitted to the acquisition module by the external power utilization equipment to a second voltage and then outputting the second voltage to the processing module. And the power supply module is used for reducing the first voltage transmitted to the power supply module by the external electric equipment to a third voltage and then outputting the third voltage to the first voltage reduction module. The first voltage reduction module is used for reducing the third voltage to obtain a first comparison voltage and a second comparison voltage and outputting 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 is used for disconnecting the driving module when the second voltage is greater than the first comparison voltage so as to disconnect the execution module; when the second voltage is smaller than the second comparison voltage, the driving module is disconnected so as to disconnect the execution module; and 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 driving module is conducted so as to conduct the execution module.

In the technical scheme of the embodiment of the application, the driving module can be disconnected when the working voltage of the external electric equipment, namely the first voltage, is detected to be too high (such as overvoltage) or too low (zero voltage, negative voltage or undervoltage and the like), so that the connection between the external electric equipment and the external power supply equipment is disconnected, and the effect of protecting the external electric equipment is achieved. After the external electric equipment is disconnected from the external power supply equipment, the connection between the external electric equipment and the external power supply equipment can be automatically conducted when the working voltage of the external electric equipment is normal, so that the external electric equipment can work normally. The circuit structure in this embodiment is comparatively simple, with low costs, easily uses widely.

In some embodiments, the power module comprises: rectifier, filter, stabiliser, first resistance and second resistance. Two input ends of the rectifier are respectively used for connecting a live wire and a zero line, and two output ends of the rectifier are respectively electrically connected to the anode of the filter and the cathode of the filter. The first resistor and the second resistor are connected in series to form a group and then connected with the filter in parallel. The voltage stabilizer is used for stabilizing the voltage of the anode of the filter according to the size proportion of the first resistor and the second resistor so as to output the third voltage to the first voltage reduction module through the anode of the filter.

In the embodiment, alternating current is converted into a direct current signal through a rectifier; and filtered by a filter. The voltage of the positive electrode of the filter can be stabilized at the third voltage through the action of the first resistor, the second resistor and the voltage stabilizer, so that a stable third voltage is provided for the first voltage reduction module.

In some embodiments, the rectifier includes a first double diode and a second double diode, and the undervoltage protection circuit further includes a voltage dependent resistor, a voltage dropping resistor and a voltage dropping capacitor. The voltage-reducing resistor and the voltage-reducing capacitor are connected in series between the input end of the voltage-sensitive resistor and the input end of the first double diode, and two output ends of the first double diode are respectively and electrically connected with the cathode of the filter and the anode of the filter. The output end of the voltage dependent resistor is electrically connected with the input end of the second double diode, and two output ends of the second double diode are respectively and electrically connected with the cathode of the filter and the anode of the filter.

In the embodiment of the application, the rectification function is realized by the first double diode and the second double diode. Energy is absorbed through the action of the piezoresistor, and surge protection is carried out on a post-stage circuit of the piezoresistor. The first voltage is reduced through the voltage reduction resistor and the voltage reduction capacitor, and the reduced first voltage is output to the power module, so that the power module reduces the voltage of the reduced first voltage to a third voltage and then outputs the third voltage to the first voltage reduction module.

In some embodiments, the processing module includes a first comparator and a second comparator. The first output end of the first voltage reduction module is electrically connected to the positive input end of the first comparator, the second output end of the first voltage reduction module is electrically connected to the positive input end of the second comparator, and the negative input end of the first comparator and the negative input end of the second comparator are electrically connected to the acquisition module respectively, so 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, the second comparison voltage is less than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a low level, so that the driving module is disconnected; when the second voltage is smaller than the second comparison voltage, the first comparison voltage is larger than the voltage of the negative input end of the first comparator, the output end of the first comparator outputs a high level, the second comparison voltage is larger than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a high level, so that the driving module is disconnected; 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, the second comparison voltage is less than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a low level, so that the driving module is switched on.

In this embodiment, the output end of the first comparator can output a high level or a low level according to a magnitude relationship between the first comparison voltage at the positive input end of the first comparator and the second voltage at the negative input end of the first comparator. And the output end of the second comparator outputs high level or low level according to the magnitude relation of the second comparison voltage at the positive input end of the second comparator and the second voltage at the negative input end of the second comparator. Therefore, the driving module is switched off or switched on according to the level relation of the outputs of the first comparator and the second comparator. And the first comparison voltage and the second comparison voltage can be different through the first voltage reduction module, so that the realizability of the technical scheme of the application is further improved.

In some embodiments, the driving module includes a first diode, the execution module is a coil, and the overvoltage and undervoltage protection circuit further includes an RC filtering module, where the RC filtering module includes a first capacitor and a third resistor. The anode of the first diode is electrically connected to the output terminal of the first comparator. The cathode 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 end of the second comparator. The first capacitor is connected in parallel with the coil, wherein the negative electrode of the first capacitor is electrically connected to one end of the coil, which is electrically connected with the output end of the second comparator. One end of the third resistor is electrically connected to the cathode of the first diode, and the other end is electrically connected to the end of the first capacitor which is not electrically connected to the output end of the second comparator.

In this embodiment, since the first diode has a unidirectional conduction function, the first diode can be in a conduction or cut-off state according to a voltage magnitude relationship between two ends of the first diode. That is, the present embodiment can make the first diode in the on or off state according to the magnitude of the voltage output by the output terminal of the first comparator and the magnitude of the voltage output by 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, that is, the first diode is turned off. When the first comparator outputs low level, the second comparator outputs low level, the first diode is cut off, namely, the diode is disconnected. When the first comparator outputs a high level and the second comparator outputs a low level, the anode of the first diode is at the high level and the cathode thereof is at the low level, so that the first diode is conducted. In addition, the voltage output by the first diode can be filtered through the first capacitor and the third resistor, so that a later-stage circuit of the first capacitor and the third resistor can obtain a relatively smooth direct-current voltage, and the reliability of normal operation of the execution module can be further improved.

In some embodiments, the first voltage reduction module comprises: 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 of resistors, and the sixth resistor and the seventh resistor are connected in parallel to form a group B of resistors. The input end of the group A resistor is electrically connected with the anode of the filter so that the voltage of the input end of the group A resistor is a third voltage, the output end of the group A resistor is electrically connected with the input end of the eighth resistor and the anode input end of the first comparator respectively, the output end of the eighth resistor is electrically connected with the input end of the group B resistor and the anode input end of the second comparator respectively, and the output end of the group B resistor is grounded.

In this embodiment, the voltage reduction effect may be achieved by the fourth resistor, the fifth resistor, the sixth resistor, the seventh resistor, and the eighth resistor, so as to provide a first comparison voltage at the positive input terminal of the first comparator and a second comparison voltage at the positive input terminal of the second comparator.

In some embodiments, the over-voltage and under-voltage protection circuit further comprises: 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.

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

In some embodiments, the acquisition module includes a rectifier diode and a second voltage reduction module. The rectifying diode rectifies the first voltage transmitted to the acquisition module, and the second voltage reduction module reduces the rectified first voltage to obtain a second voltage.

In this embodiment, half-wave rectification may be performed by the rectifying diode, and the second voltage may be obtained by a second voltage reduction module that reduces the voltage, where the second voltage is used for comparison with the first comparison voltage and the second comparison voltage, respectively. The scheme of this embodiment can make the collection module can provide comparatively stable second voltage for processing module.

In some embodiments, the second voltage reduction module comprises: an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor. The eleventh resistor, the twelfth resistor and the thirteenth resistor are sequentially connected in series, an input end of the eleventh resistor is electrically connected to a cathode of the rectifier diode, and an output end of the thirteenth resistor is electrically connected to a cathode input end of the first comparator and a cathode input end of the second comparator respectively. One end of the fourteenth resistor is electrically connected to the output end of the thirteenth resistor, and the other end is grounded.

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

In some embodiments, the overvoltage and undervoltage protection circuit further comprises a second diode; and the anode of the second diode is electrically connected to the output end of the thirteenth resistor, and the cathode of the second diode is electrically connected to the cathode input end of the first comparator and the cathode input end of the second comparator. The second diode in this embodiment has a unidirectional conduction effect, and can prevent components and parts in the subsequent circuit from being damaged when external electric equipment is reversely connected.

And/or, the over-voltage and under-voltage protection circuit further comprises a fifteenth resistor and a second capacitor; and one end of a fifteenth resistor is respectively and electrically connected with the negative input end of the first comparator and the negative input end of the second comparator, the other end of the fifteenth resistor is grounded, the voltage of the negative input end of the first comparator and the voltage of the negative input end of the second comparator are pulled up, and the second capacitor is connected with the fifteenth resistor in parallel. In this embodiment, the fifteenth resistor and the second capacitor have a filtering function, and meanwhile, a pull-up voltage may be provided to the negative input terminal of the first comparator and the negative input terminal of the second comparator, so as to improve the reliability of the normal operation of the first comparator and the second comparator.

In a second aspect, the present embodiment further provides an electric device, including: the above external consumer and the overvoltage and undervoltage protection circuit of any of the above embodiments. The external electric equipment is electrically connected with the acquisition module. And when the execution module is disconnected, the external power utilization equipment and the external power supply equipment are disconnected. And when the execution module is switched on, the connection between the external power utilization equipment and the external power supply equipment is switched on.

In this embodiment, since the power consumption device includes the over-voltage and under-voltage protection circuit of any one of the above embodiments, the embodiment can disconnect the driving module when detecting that the working voltage of the external power consumption device, that is, the first voltage is too high (such as overvoltage) or too low (such as zero voltage, negative voltage, or under-voltage, etc.), so as to disconnect the connection between the external power consumption device and the external power supply device, thereby achieving the effect of protecting the external power consumption device. After the external electric equipment is disconnected from the external power supply equipment, the connection between the external electric equipment and the external power supply equipment can be automatically conducted when the working voltage of the external electric equipment is normal, so that the external electric equipment can work normally. The circuit structure in this embodiment is comparatively simple, with low costs, easily uses widely.

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Moreover, like reference numerals are used to refer to like elements throughout. In the drawings:

FIG. 1 is a schematic diagram of an over-voltage and under-voltage protection circuit according to some embodiments of the present disclosure;

fig. 2 is a schematic circuit diagram of an over-voltage and under-voltage protection circuit according to some embodiments of the present application.

The reference numbers in the detailed description are as follows:

11-an acquisition module; 12-a power supply module; 13-a first voltage reduction module; 14-a processing module; 15-drive module, 16-execution module; RV 1-piezo-resistor; VD1 — first double diode; VD2 — second double diode; c1 — first filter capacitance; c2 — second filter capacitance; r0-voltage dropping resistor; c0-voltage reduction capacitor; VD 3-first diode; coil, Coil 1-Coil; c3 — first capacitance; IC 1-voltage stabilization chip; r1 — first resistance; r2 — second resistance; r3 — third resistance; IC2A — first comparator; IC 2B-second comparator; r4-fourth resistor; r5-fifth resistor; r6-sixth resistance; r7 — seventh resistor; r8 — eighth resistance; r9 — ninth resistor; r10 — tenth resistance; VD 4-rectifier diode; r11 — eleventh resistor; r12 — twelfth resistor; r13 — thirteenth resistor; r14-fourteenth resistance; VD5 — second diode; r15-fifteenth resistance; c4-second capacitance.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the directions or positional relationships indicated in the drawings, and are only for convenience of description of the embodiments of the present application and for simplicity of description, but do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used in a broad sense, and for example, may be fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

The following examples further illustrate the protocol of the present application:

some embodiments of the present application disclose an over-voltage and under-voltage protection circuit, please refer to fig. 1, where fig. 1 is a schematic structural diagram of the over-voltage and under-voltage protection circuit in some embodiments of the present application. As shown in fig. 1, the over-voltage and under-voltage protection circuit includes: the device comprises an acquisition module 11, a power supply module 12, a first voltage reduction module 13, a processing module 14, a driving module 15 and an execution module 16. The collection module 11 reduces the first voltage transmitted from the external power consumption device to the collection module 11 to a second voltage, and outputs the second voltage to the processing module 14. The power module 12 steps down the first voltage transmitted from the external power consumption device to the power module 12 to a third voltage, and outputs the third voltage to the first voltage step-down module 13. The first voltage dropping module 13 drops 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. Wherein the first comparison voltage is greater than the second comparison voltage. The processing module 14 switches off the driving module 15 to switch off the execution module 16 when the second voltage is greater than the first comparison voltage. The processing module 14 switches off the driving module 15 to switch off the execution module 16 when the second voltage is less than the second comparison voltage. The processing module 14 turns on the driving module 15 to turn on the execution module 16 when the second voltage is greater than or equal to the second comparison voltage and less than or equal to the first comparison voltage.

It should be noted that the values of the second voltage, the first comparison voltage, and the second comparison voltage may be set according to the type and the operating voltage of the actual external consumer. The values of the second voltage, the first comparison voltage and the second comparison voltage are not limited in the present application.

In practical applications, when the external power consumption device needs to operate, the external power consumption device can be connected to the external power supply device, for example, the external power supply device may be an ac power supply. At this time, the first voltage transmitted to the acquisition module 11 by the external electric device is the voltage of the ac power supply, and is a voltage that changes in real time. And the first voltage may not only change its direction but also change its magnitude under the influence of external environment and other factors.

Specifically, when the external power consumption device is connected to the external power supply device, if the collection module 11 collects the operating voltage of the external power consumption device, that is, the first voltage is too high and exceeds the load of the external power consumption device (for example, overvoltage), the second voltage after voltage reduction is greater than the first comparison voltage VH, and at this time, the driving module 15 is turned off. When the driving module 15 is disconnected, the tripper is not electrified, and the product is in a tripping state and cannot be switched on. At this time, the external electric equipment is disconnected from the external power supply equipment and cannot be conducted. The product may refer to an earth leakage breaker or a switch, etc., which are not listed here.

If the working voltage of the external power consumption device, that is, the first voltage is too low (such as zero voltage, negative voltage or undervoltage, or undervoltage) acquired by the acquisition module 11, the second voltage is lower than the second comparison voltage VL, and at this time, the driving module 15 is turned off. When the driving module 15 is disconnected, the tripper is not electrified, and the product is in a tripping state and cannot be switched on. At this time, the external electric equipment is disconnected from the external power supply equipment and cannot be conducted.

If the working voltage of the external power consumption device, that is, the first voltage, is collected by the collection module 11 to be normal, the second voltage is greater than or equal to the second comparison voltage VL and less than or equal to the first comparison voltage VH, and then the driving module 15 is turned on. When the driving module 15 is switched on, the tripper is powered on, and the product can be normally switched on. At this time, the connection between the external electric device and the external power supply device can be conducted.

In summary, in the technical solution of this embodiment, when it is detected that the working voltage of the external electric device is too high, i.e., overvoltage, or too low, i.e., zero voltage, negative voltage, or undervoltage, the driving module 15 is turned off, so as to disconnect the external electric device from the external power supply device, and achieve the effect of protecting the external electric device when the working voltage of the external electric device is too high or too low. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

Referring to fig. 2, fig. 2 is a schematic circuit diagram of an over-voltage and under-voltage protection circuit according to some embodiments of the present application. The present embodiment includes the following technical features in addition to the technical features of any of the above embodiments:

as shown in fig. 1 and 2, the power supply module 12 includes: rectifier, filter, stabiliser, first resistance R1 and second resistance R2. Two input ends of the rectifier are respectively used for connecting a live wire and a zero line, and two output ends of the rectifier are respectively electrically connected to the anode of the filter and the cathode of the filter. The first resistor R1 and the second resistor R2 are connected in series to form a group and then are connected with the filter in parallel. The voltage stabilizer is used for stabilizing the voltage of the anode of the filter according to the size ratio of the first resistor R1 and the second resistor R2, so as to output the third voltage to the first voltage-reducing module 13 through the anode of the filter. For example, the negative pole of the filter may be used as the ground GND, and the positive pole of the filter is electrically connected to the first voltage-decreasing module 13. Converting the alternating current into a direct current signal through a rectifier; and filtered by a filter. The voltage of the positive electrode of the filter can be stabilized at the third voltage by the action of the first resistor R1, the second resistor R2 and the voltage stabilizer, so as to provide a more stable third voltage to the first voltage-reducing module 13. For example, the voltage of the positive electrode of the filter, i.e., V + in the figure, can be stabilized by 8V, 9V, 10V, etc. according to the size ratio of the first resistor R1 and the second resistor R2, which are not illustrated here.

The voltage regulator in this embodiment may be a voltage regulator IC1, specifically, the first terminal of the voltage regulator is electrically connected to the positive electrode of the filter, the output terminal of the voltage regulator IC1 is electrically connected to the positive electrode of the filter, and the second terminal ground GND of the voltage regulator may be the ground terminal or the input terminal ground GND of the voltage regulator IC 1. The third terminal of the regulator is electrically connected between the first resistor R1 and the second resistor R2, which may mean that the input terminal of the regulator chip IC1 is connected between the first resistor R1 and the second resistor R2. When the current through voltage regulation chip IC1 changes in a large range, the voltage at the two ends of voltage regulation chip IC1 maintains balance, thereby realizing the voltage regulation function, and the cost of voltage regulation chip IC1 is lower, and the cost of the overvoltage and undervoltage protection circuit can be reduced to a certain extent.

The rectifier comprises a first double diode VD1 and a second double diode VD2, and the overvoltage and undervoltage protection circuit further comprises a piezoresistor RV1, a step-down resistor R0 and a step-down capacitor C0. The voltage-reducing resistor R0 and the voltage-reducing capacitor C0 are connected in series between the input end of the voltage-dependent resistor RV1 and the input end of the first double diode VD 1. Two output ends of the first double diode VD1 are electrically connected to the cathode of the filter and the anode of the filter, respectively. The output end of the piezoresistor RV1 is electrically connected to the input end of the second double diode VD2, and two output ends of the second double diode VD2 are electrically connected to the cathode of the filter and the anode of the filter respectively.

For example, the input end of the piezoresistor RV1 is used for being electrically connected with the live line L, and the output end of the piezoresistor RV1 is used for being electrically connected with the neutral line N. The voltage reduction resistor R0 is connected in series with the voltage reduction capacitor C0. The input end of the voltage-reducing resistor R0 is used for connecting a live wire L, and the output end of the voltage-reducing capacitor C0 is electrically connected to the input end of the first double diode VD 1. Or, the input end of the step-down capacitor C0 is used for connecting the live line L, and the output end of the step-down resistor R0 is electrically connected to the input end of the first double diode VD 1.

The rectifying effect is realized by the first double diode VD1 and the second double diode VD 2. Energy is absorbed through the action of the piezoresistor RV1, and the surge protection is carried out on the post-stage circuit of the piezoresistor RV 1. The first voltage is reduced through the voltage reduction resistor R0 and the voltage reduction capacitor C0, and the reduced first voltage is output to the power module 12, so that the power module 12 reduces the voltage of the reduced first voltage to a third voltage and then outputs the third voltage to the first voltage reduction module 13.

In addition, the first double diode VD1 includes two diodes connected in series; the input end of the voltage dependent resistor RV1 is electrically connected to the input end of a first double diode VD1, wherein the input end of the first double diode VD1 is between 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 end of the first double diode VD1 is connected to the ground GND, and the negative output end of the first double diode VD1 is electrically connected to the positive electrode of the filter. The second double diode VD2 includes two diodes connected in series; the output end of the voltage dependent resistor RV1 is electrically connected with the input end of a second double diode VD2, wherein the input end of the second double diode VD2 is connected between two diodes connected in series. The two outputs of the second double diode VD2 include a positive output and a negative output. The positive output end of the second double diode VD2 is connected with the ground wire GND, and the negative output end of the second double diode VD2 is electrically connected with the positive electrode of the filter.

The filter may include a first filter capacitor C1, the positive electrode of the first filter capacitor C1 is electrically connected to the positive electrode of the filter, and the negative electrode is grounded to GND for filtering. The filter may further include a second filter capacitor C2, and the second filter capacitor C2 may be a common capacitor without separating positive and negative electrodes. One end of the second filtering capacitor C2 is electrically connected to the anode of the filter, and the other end is electrically connected to the ground GND for further filtering, thereby improving the filtering effect.

In the actual circuit design process, the processing module 14 includes a first comparator IC2A and a second comparator IC 2B. The first output end of the first voltage-reducing module 13 is electrically connected to the positive input end of the first comparator IC2A, the second output end of the first voltage-reducing module 13 is electrically connected to the positive input end of the second comparator IC2B, and the negative input end of the first comparator IC2A and the negative input end of the second comparator IC2B are electrically connected to the collecting module 11 respectively, so 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 terminal of the first comparator IC2A, the output terminal of the first comparator IC2A outputs a low level, the second comparison voltage is less than the voltage of the negative input terminal of the second comparator IC2B, and the output terminal of the second comparator IC2B outputs a low level, so that the driving module 15 is turned off; when the second voltage is smaller than the second comparison voltage, the first comparison voltage is larger than the voltage of the negative input terminal of the first comparator IC2A, the output terminal of the first comparator IC2A outputs a high level, the second comparison voltage is larger than the voltage of the negative input terminal of the second comparator IC2B, and the output terminal of the second comparator IC2B outputs a high level, so that the driving module 15 is turned off; 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, the second comparison voltage is less than the voltage at the negative input terminal of the second comparator IC2B, and the output terminal of the second comparator IC2B outputs a low level, so that the driving module 15 is turned on.

In this embodiment, the output terminal of the first comparator IC2A can output a high level or a low level according to 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 IC 2A. The output terminal of the second comparator IC2B outputs a high level or a low level according to 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 IC 2B. Thereby turning off or on the driving module 15 according to the level relationship of the outputs of the first and second comparators IC2A and IC 2B. Moreover, the first voltage reduction module 13 can make the first comparison voltage and the second comparison voltage different from each other, so as to further improve the realizability of the technical solution of the present application.

The driving module 15 includes a first diode VD3, and the executing module 16 is a Coil 1. The undervoltage protection circuit further comprises an RC filtering module, wherein the RC filtering module comprises a first capacitor C3 and a third resistor R3. The anode of the first diode VD3 is electrically connected to the output terminal of the first comparator IC 2A. The cathode of the first diode VD3 is electrically connected to one end of the Coil1, and the other end of the Coil1 is electrically connected to the output terminal of the second comparator IC 2B. The first capacitor C3 is connected in parallel with the Coil1, wherein the negative electrode of the first capacitor C3 is electrically connected to one end of the Coil1, which is electrically connected to the output terminal of the second comparator IC 2B. One end of the third resistor R3 is electrically connected to the cathode 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 IC 2B. The voltage output by the first diode VD3 is filtered by the first capacitor C3 and the third resistor R3, so that a smoother dc voltage can be obtained by the subsequent circuits of the first capacitor C3 and the third resistor R3, and the reliability of the normal operation of the execution module 16 can be further improved.

In this embodiment, since the first diode VD3 has a unidirectional conduction function, the first diode VD3 can be turned on or off according to the voltage magnitude relationship between the two ends of the first diode VD 3. That is, the present embodiment can make the first diode VD3 in the conducting or cut-off state by the voltage outputted from the output terminal of the first comparator IC2A and the voltage outputted from the output terminal of the second comparator IC 2B. 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 turned off, i.e., turned off. When the first comparator IC2A outputs a low level and the second comparator IC2B outputs a low level, the first diode VD3 is turned off, i.e., turned off. 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 set to a high level and the negative electrode thereof is set to a low level, so that the first diode VD3 is turned on. When the first diode VD3 is turned on, the Coil1 is turned on to turn on the connection of the external power-consuming device and the external power-supplying device. When the first diode VD3 is disconnected, the Coil1 is disconnected to disconnect the external power-consuming equipment from the external power-supplying equipment. Coil 1's cost is lower, and the working method is comparatively reliable, can reduce the cost of crossing undervoltage protection circuit to a certain extent, promotes voltage protection circuit's reliability.

It should be noted that the first voltage reduction 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 of resistors, and the sixth resistor R6 and the seventh resistor R7 are connected in parallel to form a group B of resistors. The input end of the group A resistor is electrically connected to the anode of the filter so that the voltage at the input end of the group A resistor is a third voltage, the output end of the group A resistor is electrically connected to the input end of the eighth resistor R8 and the anode input end of the first comparator IC2A respectively, the output end of the eighth resistor R8 is electrically connected to the input end of the group B resistor and the anode input end of the second comparator IC2B respectively, and the output end of the group B resistor is grounded. The above voltage dropping effect may be achieved by the action of the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8 to provide a first comparison voltage at the positive input terminal of the first comparator IC2A and a second comparison voltage at the positive input terminal of the second comparator IC 2B.

In addition, the overvoltage and undervoltage protection circuit further comprises: a ninth resistor R9 and a tenth resistor R10. One end of the ninth resistor R9 is electrically connected to the positive input terminal of the first comparator IC2A, and the other end is electrically connected to the output terminal of the first comparator IC 2A. One end of the tenth resistor R10 is electrically connected to the positive input terminal of the second comparator IC2B, and the other end is electrically connected to the output terminal of the second comparator IC 2B. The ninth resistor R9 in this embodiment can protect the first comparator IC2A and prevent the first comparator IC2A from being damaged due to exceeding the withstand voltage. The tenth resistor R10 in this embodiment can protect the second comparator IC2B and prevent the second comparator IC2B from being damaged due to exceeding the withstand voltage.

Optionally, the acquisition module 11 includes a rectifying diode VD4 and a second voltage reduction module. The rectifying diode VD4 rectifies the first voltage transmitted to the acquisition module 11, and the second voltage reduction module reduces the rectified first voltage to obtain a second voltage. In this embodiment, half-wave rectification may be performed by the rectifying diode VD4, and the second voltage is obtained by voltage reduction performed by the second voltage reduction module, and the second voltage is respectively used for comparison with the first comparison voltage and the second comparison voltage. The scheme of this embodiment may enable the acquisition module 11 to provide a relatively stable second voltage to the processing module 14.

Specifically, the second voltage reduction module includes: an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a fourteenth resistor R14. An eleventh resistor R11, a twelfth resistor R12 and a thirteenth resistor R13 are connected in series in sequence, an input end of the eleventh resistor R11 is electrically connected to a negative electrode of the rectifying diode VD4, and an output end of the thirteenth resistor R13 is electrically connected to a negative electrode input end of the first comparator IC2A and a negative electrode input end of the second comparator IC2B respectively. One end of the fourteenth resistor R14 is electrically connected to the output terminal of the thirteenth resistor R13, and the other end is connected to the ground.

In this embodiment, the magnitude of the second voltage transmitted to the negative input terminal of the first comparator IC2A and the negative input terminal of the second comparator IC2B is determined by the magnitude relationship of the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13 and the fourteenth resistor R14.

The overvoltage and undervoltage protection circuit further comprises a second diode VD 5; and the anode of the second diode VD5 is electrically connected to the output terminal of the thirteenth resistor R13, and the cathode is electrically connected to the cathode input terminal of the first comparator IC2A and the cathode input terminal of the second comparator IC 2B. The second diode VD5 in this embodiment has a unidirectional conduction function, and can prevent components in the subsequent circuit from being damaged when the external power consumption device is reversely connected.

In the actual circuit design process, the overvoltage and undervoltage protection circuit further comprises a fifteenth resistor R15 and a second capacitor C4; and one end of a fifteenth resistor R15 is electrically connected to the negative input terminal of the first comparator IC2A and the negative input terminal of the second comparator IC2B respectively, the other end is grounded to pull up the voltage of the negative input terminal of the first comparator IC2A and the negative input terminal of the second comparator IC2B, and the second capacitor C4 and the fifteenth resistor R15 are connected in parallel. In this embodiment, the fifteenth resistor R15 and the second capacitor C4 have a filtering function, and may provide a pull-up voltage to the negative input terminal of the first comparator IC2A and the negative input terminal of the second comparator IC2B, so as to improve the reliability of the normal operation of the first comparator IC2A and the second comparator IC 2B.

The filter further comprises a third capacitor C5, one end of the third capacitor C5 is electrically connected to the anode of the filter, and the other end of the third capacitor C5 is connected to the ground GND. The third capacitor C5 in this embodiment can filter and provide a smooth voltage for the subsequent circuits of the first comparator IC2A and the second comparator IC 2B.

The operation principle of the present embodiment is further described below with reference to fig. 2:

the overvoltage and undervoltage protection circuit of the present application can be used on external consumers, which are commonly referred to in the art as loads. For example, in the present application, when the Coil1 in the overvoltage/undervoltage protection circuit is disconnected, the external power consumption device is disconnected from the external power supply device. Or in another embodiment, when the Coil1 in the voltage protection circuit is turned on, the connection between the external power consumption device and the external power supply device is turned on.

Such as: the external electric equipment can be connected into a live wire L and a zero wire N of alternating current in a mode of matching a switch or a plug with a socket and the like. The alternating current is not limited, and can be 230V or 220V, and the like, and in practical application, the alternating current can be determined according to the working voltage of the external electric equipment during normal working. When the external electric equipment is connected to the live line L and the neutral line N of the alternating current, the overvoltage and undervoltage protection circuit is also connected to the live line L and the neutral line N of the alternating current through the first pin J1 and the second pin J2.

In summary, when the first voltage collected by the sampling module is over-voltage or zero-voltage, negative-voltage or no-voltage, Coil1 is turned off. And when the first voltage acquired by the sampling module is the voltage required by the operation of the external electric equipment, the Coil1 is conducted.

When Coil1 is closed, the connection between the external power utilization equipment and the external power supply equipment is conducted. When Coil1 is disconnected, the external power consumption device is disconnected from the external power supply device. Therefore, in this embodiment, the overvoltage/undervoltage protection circuit can be used to disconnect the driving module 15 when detecting that the working voltage of the external power consumption device is too high, i.e., overvoltage, or too low, i.e., zero voltage, negative voltage, or undervoltage, so as to disconnect the connection between the external power consumption device and the external power supply device, thereby achieving the effect of protecting the external power consumption device when the working voltage of the external power consumption device is too high or too low. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

Another embodiment of the present application discloses an embodiment further provides an electric device, including: the above external consumer and the overvoltage and undervoltage protection circuit of any of the above embodiments. The external electric equipment is electrically connected with the acquisition module. And when the execution module is disconnected, the external power utilization equipment and the external power supply equipment are disconnected. And when the execution module is switched on, the connection between the external power utilization equipment and the external power supply equipment is switched on.

In this embodiment, since the power consumption device includes the overvoltage/undervoltage protection circuit according to any one of the above embodiments, the present embodiment can disconnect the driving module when detecting that the working voltage of the external power consumption device, that is, the first voltage, is not within the preset voltage range through the overvoltage/undervoltage protection circuit, so as to disconnect the external power consumption device from the external power supply device, and achieve an effect of protecting the external power consumption device when the working voltage of the external power consumption device is not within the preset voltage range. In this embodiment, when the operating voltage of the external power device is within the preset voltage range, the connection between the external power device and the external power supply device is automatically turned on, so that the external power device normally operates. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use. In addition, in practical applications, the voltage outside the predetermined voltage range may be greater than the maximum value in the predetermined voltage range, i.e., an overvoltage. Alternatively, it may be any positive voltage less than the minimum value in the preset voltage range, i.e., zero voltage, negative voltage, or less than the minimum value in the preset voltage range, and the like, which are not listed here.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. An over-voltage and under-voltage protection circuit, comprising: the device comprises an acquisition module, a power supply module, a first voltage reduction module, a processing module, a driving module and an execution module;

the acquisition module is used for reducing a first voltage transmitted to the acquisition module by external electric equipment to a second voltage and outputting the second voltage to the processing module;

the power supply module is used for reducing a first voltage transmitted to the power supply module by the external electric equipment to a third voltage and outputting the third voltage to the first voltage reduction module;

the first voltage reduction module reduces 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 is used for switching off the driving module when the second voltage is greater than the first comparison voltage so as to switch off the execution module; when the second voltage is smaller than the second comparison voltage, the driving module is switched off so as to switch off the execution module; and 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 driving module is conducted so as to conduct the execution module.

2. The over-voltage and under-voltage protection circuit of claim 1, wherein the power module comprises: the device comprises a rectifier, a filter, a voltage stabilizer, a first resistor and a second resistor;

two input ends of the rectifier are respectively used for connecting a live wire and a zero line, and two output ends of the rectifier are respectively electrically connected to the anode of the filter and the cathode of the filter;

the first resistor and the second resistor are connected in series to form a group and then connected with the filter in parallel;

the voltage stabilizer is used for stabilizing the voltage of the anode of the filter at the third voltage according to the size proportion of the first resistor and the second resistor, so that the third voltage is output to the first voltage reduction module through the anode of the filter.

3. The overvoltage-undervoltage protection circuit according to claim 2, wherein the rectifier includes a first double diode and a second double diode, the overvoltage-undervoltage protection circuit further includes a voltage dependent resistor, a voltage dropping resistor and a voltage dropping capacitor;

the voltage-reducing resistor and the voltage-reducing capacitor are connected in series between the input end of the voltage-sensitive resistor and the input end of the first double diode, and two output ends of the first double diode are respectively and electrically connected to the cathode of the filter and the anode of the filter;

the output end of the piezoresistor is electrically connected to the input end of the second double diode, and the two output ends of the second double diode are respectively and electrically connected to the cathode of the filter and the anode of the filter.

4. The under-voltage and over-voltage protection circuit according to claim 2 or 3, wherein the processing module comprises a first comparator and a second comparator;

the first output end of the first voltage reduction module is electrically connected to the positive input end of the first comparator, the second output end of the first voltage reduction module is electrically connected to the positive input end of the second comparator, and the negative input end of the first comparator and the negative input end of the second comparator are electrically connected to the acquisition module respectively, so 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, the second comparison voltage is less than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a low level, so that the driving module is switched off;

when the second voltage is smaller than the second comparison voltage, the first comparison voltage is larger than the voltage of the negative input end of the first comparator, the output end of the first comparator outputs a high level, the second comparison voltage is larger than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a high level, so that the driving module is switched off;

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, the second comparison voltage is less than the voltage of the negative input end of the second comparator, and the output end of the second comparator outputs a low level, so that the driving module is switched on.

5. The over-voltage and under-voltage protection circuit of claim 4, wherein the driving module comprises a first diode, the execution module is a coil, and the over-voltage and under-voltage protection circuit further comprises an RC filter module, wherein the RC filter module comprises a first capacitor and a third resistor;

the anode of the first diode is electrically connected to the output end 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 end of the second comparator;

the first capacitor is connected with the coil in parallel, wherein the negative electrode of the first capacitor is electrically connected with one end of the coil, which is electrically connected with the output end of the second comparator;

one end of the third resistor is electrically connected to the cathode of the first diode, and the other end of the third resistor is electrically connected to the end of the first capacitor which is not electrically connected to the output end of the second comparator.

6. The under-voltage and over-voltage protection circuit of claim 4, wherein the first voltage-reducing module comprises: 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 of resistors, and the sixth resistor and the seventh resistor are connected in parallel to form a group B of resistors;

the input end of the group A resistor is electrically connected to the anode of the filter so that the voltage at the input end of the group A resistor is the third voltage, the output end of the group A resistor is electrically connected to the input end of the eighth resistor and the anode input end of the first comparator respectively, the output end of the eighth resistor is electrically connected to the input end of the group B resistor and the anode input end of the second comparator respectively, and the output end of the group B resistor is grounded.

7. The undervoltage protection circuit of claim 4, wherein the undervoltage protection circuit further comprises: 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 of the ninth resistor 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 of the tenth resistor is electrically connected to the output end of the second comparator.

8. The over-voltage and under-voltage protection circuit according to claim 4, wherein the collecting module comprises a rectifier diode and a second voltage-reducing module;

the rectifier diode rectifies the first voltage transmitted to the acquisition module, and the second voltage reduction module reduces the rectified first voltage to obtain a second voltage.

9. The under-voltage and over-voltage protection circuit of claim 8, wherein the second voltage-reducing module comprises: an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor;

the eleventh resistor, the twelfth resistor and the thirteenth resistor are sequentially connected in series, an input end of the eleventh resistor is electrically connected to a cathode of the rectifier diode, and an output end of the thirteenth resistor is electrically connected to a cathode input end of the first comparator and a cathode input end of the second comparator respectively;

one end of the fourteenth resistor is electrically connected to the output end of the thirteenth resistor, and the other end of the fourteenth resistor is grounded.

10. The under-voltage and over-voltage protection circuit of claim 9, further comprising a second diode; and is

The positive electrode of the second diode is electrically connected to the output end of the thirteenth resistor, and the negative electrode of the second diode is electrically connected to the negative electrode input end of the first comparator and the negative electrode input end of the second comparator;

and/or the presence of a gas in the gas,

the over-voltage and under-voltage protection circuit further comprises a fifteenth resistor and a second capacitor; and is

One end of the fifteenth resistor is electrically connected to the negative input end of the first comparator and the negative input end of the second comparator respectively, the other end of the fifteenth resistor is connected to the ground wire to pull up the voltage 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.