CN217063256U - Voltage protection circuit and electric device - Google Patents

Abstract

The application discloses voltage protection circuit and consumer. The voltage protection circuit includes: the device comprises an acquisition module, a comparison module, a driving module and an on-off module; the acquisition module acquires a first voltage transmitted to the acquisition module by external electric equipment and transmits the first voltage to the comparison module; the comparison module compares the first voltage with a first preset voltage, and is disconnected when the first voltage is smaller than the first preset voltage, the drive module is disconnected when the comparison module is disconnected, and the on-off module is disconnected when the drive module is disconnected, wherein the first preset voltage is a positive number. In the embodiment of the application, the on-off module can be switched off when the working voltage of the external electric equipment, namely the first voltage, is lower than the first preset voltage, 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 when the working voltage of the external electric equipment is lower than the first preset voltage.

Description

Voltage protection circuit and electric device

Technical Field

The application relates to the technical field of power supply control circuits, in particular to a voltage protection circuit and an electric device.

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 normally work, overvoltage or undervoltage and other conditions may 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.

SUMMERY OF THE UTILITY MODEL

In view of the above problem, the present application provides a voltage protection circuit and an electric device, where the voltage protection circuit can disconnect a switching module when detecting that an operating voltage of an external electric device is lower than a first preset voltage, so as to disconnect the external electric device from an external power supply device, and achieve an effect of protecting the external electric device when the operating voltage of the external electric device is lower than the first preset voltage.

In one aspect, the present application provides a voltage protection circuit, comprising: the device comprises an acquisition module, a comparison module, a driving module and an on-off module. The acquisition module acquires a first voltage transmitted to the acquisition module by external electric equipment and transmits the first voltage to the comparison module. The comparison module compares the first voltage with a first preset voltage, and is disconnected when the first voltage is smaller than the first preset voltage, the drive module is disconnected when the comparison module is disconnected, and the on-off module is disconnected when the drive module is disconnected; wherein the first preset voltage is a positive number.

In the technical scheme of the embodiment of the application, the on-off module can be disconnected when the working voltage of the external electric equipment, namely the first voltage, is lower than the first preset voltage, 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 when the working voltage of the external electric equipment is lower than the first preset voltage. In practical applications of the present embodiment, when the first voltage is lower than the first preset voltage, the first voltage may be any value lower than the first preset voltage. For example, the first voltage may be zero voltage, negative voltage, other positive voltage smaller than the first preset voltage, and the like, which are not listed here. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

In some embodiments, the comparison module compares the first voltage with a second preset voltage, and is turned on when the first voltage is greater than the second preset voltage, the driving module is turned on when the comparison module is turned on, and the on-off module is turned on when the driving module is turned on; the second preset voltage is greater than the first preset voltage.

In this embodiment, after the connection between the external electrical device and the external power supply device is disconnected, when the operating voltage at which the external electrical device is operating is greater than the second preset voltage, the connection between the external electrical device and the external power supply device may be automatically turned on, so that the external electrical device operates normally.

In some embodiments, the voltage protection circuit further comprises a power module; the power supply module converts the first voltage acquired by the acquisition module into a second voltage, and transmits the second voltage to the driving module, the comparison module and the on-off module respectively so as to provide the second voltage for enabling the driving module, the comparison module and the on-off module to work normally. The value of the second voltage is smaller than that of the first voltage, and the second voltage is direct current voltage.

In this embodiment, the power module may convert the first voltage acquired by the acquisition module into a second voltage required by the operation of the driving module, the comparison module, and the on-off module, so as to improve the reliability of the normal operation of the driving module, the comparison module, and the on-off module.

In some embodiments, the drive module comprises: the first triode, the first resistor and the field effect transistor; the base electrode of the first triode is electrically connected with the comparison module, the emitting electrode of the first triode is grounded, the collector electrode of the first triode is electrically connected with the first end of the first resistor and the grid electrode of the field effect tube respectively, and the second end of the first resistor is connected with the drain electrode of the field effect tube and is electrically connected with the power supply module; the source electrode of the field effect transistor is electrically connected with the on-off module.

In this embodiment, the on-off of the on-off module can be controlled by the on-off of the field effect transistor, and compared with a common triode field effect transistor, the breakdown voltage is higher, so that the field effect transistor can realize a long-time working state through a larger current, and the on-off module is switched on for a long time, so that the external electric equipment works for a long time.

In some embodiments, the field effect transistor is an N-channel parasitic MOS transistor; and/or the first triode is an NPN triode. In the embodiment, the diode of the N-channel parasitic MOS tube can prevent the MOS tube in the N-channel parasitic MOS tube from being burnt out when the voltage of the N-channel parasitic MOS tube is overlarge, and can also prevent the MOS tube in the N-channel parasitic MOS tube from being burnt out when the source electrode and the drain electrode of the N-channel parasitic MOS tube are reversely connected.

In some embodiments, the switching module is a coil; one end of the coil is electrically connected to the source electrode of the field effect transistor, and the other end of the coil is grounded.

In some embodiments, the power module includes a voltage dependent resistor, a rectifier bridge, and a first capacitor; two input ends of the rectifier bridge are respectively and electrically connected with one end of the first capacitor and the first end of the piezoresistor, a positive output end of the rectifier bridge is electrically connected with a drain electrode of the field effect transistor, and a negative output end of the rectifier bridge is grounded; the other end of the first capacitor is electrically connected with the second end of the piezoresistor; two receiving ends are led out from the first end of the piezoresistor and the second end of the piezoresistor respectively, and the two receiving ends are used for being electrically connected with a live wire and a zero line of external electric equipment respectively.

In this embodiment, energy may be absorbed by the varistor when the first voltage increases, so as to ensure reliable operation of a subsequent circuit of the voltage protection circuit. And through the action of the piezoresistor, when the first voltage reaches a second preset voltage, the normal power supply of a post-stage circuit of the voltage protection circuit is ensured. The first capacitor can step down the first voltage to reach the working voltage of the post-stage circuit of the voltage protection circuit. The rectifier bridge can convert alternating current into direct current signals so as to further improve the reliability of normal operation of the driving module and the comparison module.

In some embodiments, the power module further comprises a second capacitor; one end of the second capacitor is electrically connected to the positive output end of the rectifier bridge, and the other end of the second capacitor is grounded. The second capacitor in this embodiment may filter the voltage output by the rectifier bridge, so that a post-stage circuit of the second capacitor may obtain a relatively smooth dc voltage, thereby further improving the reliability of the normal operation of the driving module and the comparing module.

In some embodiments, the comparison module is a second triode; the base electrode of the second triode is electrically connected with the acquisition module, the emitting electrode of the second triode is grounded, and the collecting electrode of the second triode is electrically connected with the base electrode of the first triode. In this embodiment, the preset voltage of the comparison module may be a conduction voltage Vbe of the second triode, where the conduction voltage Vbe is a voltage difference between a base of the second triode and an emitter of the second triode. In summary, in this embodiment, the second voltage and the base conducting voltage Vbe of the second transistor are used as the comparison signal, when the second voltage is less than Vbe, the second transistor is turned off, and when the second voltage is greater than Vbe, the second transistor is turned on.

In some embodiments, the voltage protection circuit further comprises a pull-up resistor; the first end of the pull-up resistor is electrically connected to the acquisition module, and the second end of the pull-up resistor is electrically connected to the collector electrode of the second triode; the acquisition module provides pull-up voltage for the second triode through the pull-up resistor. In this embodiment, the pull-up resistor may provide a pull-up voltage to a collector of the second triode, so as to improve the stability of the normal operation of the second triode.

In some embodiments, the acquisition module comprises a depressurization processing module; the voltage reduction processing module is used for carrying out voltage reduction processing on the collected first voltage to obtain a third voltage, outputting the third voltage to the comparison module, enabling the third voltage to be smaller than the driving voltage of the comparison module when the first voltage is smaller than a first preset voltage, and enabling the third voltage to be larger than the driving voltage of the comparison module when the first voltage is larger than a second preset voltage; the process of comparing the first voltage with the first preset voltage by the comparison module comprises the following steps: and comparing the first voltage converted into the third voltage with the driving voltage.

In some embodiments, the buck processing module comprises: the temperature compensation circuit comprises a rectifier diode, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor and a temperature compensation diode; the positive electrode of the rectifier diode is electrically connected with a live wire of external electric equipment to collect first voltage; the negative pole of the rectifier diode is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to one end of the third capacitor, and the other end of the third capacitor is grounded; the first end of the third resistor is electrically connected to the second end of the second resistor, and the second end of the third resistor is electrically connected to the first end of the fourth resistor and the first end of the fifth resistor respectively; a second end of the fourth resistor is grounded; a second end of the fifth resistor is electrically connected to the first end of the sixth resistor and the comparison module respectively so as to output the third voltage to the comparison module; the second end of the sixth resistor is electrically connected to the first end of the seventh resistor; the second end of the seventh resistor is electrically connected to one end of the temperature compensation diode; the other end of the temperature compensation diode is grounded.

In this embodiment, half-wave rectification may be performed through the rectifying diode, and the second voltage is obtained by stepping down the second resistor, the third resistor, the fourth resistor, the fifth resistor, the sixth resistor, and the seventh resistor, and is used for comparing with the preset voltage of the comparing module. And the third capacitor of this embodiment may be filtered. Therefore, the scheme of the embodiment can enable the acquisition module to transmit the stable second voltage to the comparison module. In addition, the temperature compensation diode can perform temperature compensation on the comparison module and the driving module, and can improve the stability of the comparison module and the driving module during working.

In some embodiments, the voltage protection circuit further comprises a voltage regulation module; the voltage stabilizing module is electrically connected between the comparing module and the collecting module. The embodiment can provide a stable voltage for the comparison module through the voltage stabilizing module.

In some embodiments, the voltage regulation module is a zener diode; the anode of the voltage stabilizing diode is electrically connected with the comparison module, and the cathode of the voltage stabilizing diode is electrically connected with the acquisition module. The voltage stabilizing diode can keep the voltage at the two ends of the voltage stabilizing diode balanced when the current passing through the voltage stabilizing diode changes in a large range, thereby realizing the voltage stabilizing function, and the cost of the voltage stabilizing diode is lower, so that the cost of the voltage protection circuit can be reduced to a certain extent.

In a second aspect, the present embodiment further provides an electric device, including: the external power consumption device and the voltage protection circuit of any of the above embodiments; the external electric equipment is electrically connected with the acquisition module; when the on-off module is disconnected, the external power utilization equipment and the external power supply equipment are disconnected; when the on-off module is switched on, the connection between the external electric equipment and the external power supply equipment is switched on.

In this embodiment, since the power consumption device includes the voltage protection circuit according to any one of the above embodiments, in this embodiment, when the working voltage of the external power consumption device is lower than the first preset voltage, the connection between the external power consumption device and the external power supply device may be disconnected, so as to achieve an effect of protecting the external power consumption device. In this embodiment, when the operating voltage at which the external power consumption device is operating is greater than the second preset voltage, the connection between the external power consumption device and the external power supply device may be automatically turned on, so that the external power consumption device operates normally. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

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. Also, like parts are designated by like reference numerals throughout the drawings. In the drawings:

FIG. 1 is a schematic diagram of a voltage protection circuit according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram of a voltage protection circuit according to some embodiments of the present application;

fig. 3 is a circuit schematic of a voltage protection circuit in some embodiments of the present application.

The reference numbers in the detailed description are as follows:

11-an acquisition module; 12-a comparison module; 13-a drive module; 14-an on-off module; 21-a power supply module; VT 1-first triode; r1 — first resistance; q1-field effect transistor; coil, Coil 1; RV 1-piezoresistor; DB 1-rectifier bridge; c1 — first capacitance; c2 — second capacitance; VT 2-second transistor; VD 1-Zener diode; VD 2-rectifier diode; r2 — second resistance; r3 — third resistance; r4 — fourth resistance; r5 — fifth resistance; r6 — sixth resistance; r7 — seventh resistor; c3 — third capacitance; VD 3-temperature compensation diode; r8-pull-up resistor; an L-fire line; the N-zero line.

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.

Reference herein to "an embodiment" means that a particular feature, mechanism, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.

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 associated objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two sets), "plural pieces" refers to two or more (including two pieces).

In the description of the embodiments of the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships that are based on the orientations and positional relationships shown in the drawings, and are used for convenience in describing the embodiments of the present application and for simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, 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; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. 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:

referring to fig. 1, fig. 1 is a schematic structural diagram of a voltage protection circuit according to some embodiments of the present disclosure. As shown in fig. 1, the voltage protection circuit includes: the device comprises an acquisition module 11, a comparison module 12, a driving module 13 and a switching module 14. The acquisition module 11 acquires a first voltage transmitted to the acquisition module 11 by the external power consumption device, and transmits the first voltage to the comparison module 12. The comparison module 12 compares the first voltage with a first preset voltage, and when the first voltage is smaller than the first preset voltage, the comparison module 12 is turned off, the driving module 13 is turned off when the comparison module 12 is turned off, and the on-off module 14 is turned off when the driving module 13 is turned off. Wherein, the first preset voltage is positive.

For example, in an actual design process, the first preset voltage may be designed to be 161V, but it should be understood that the embodiment of the present application does not limit the first preset voltage to be 161V, and the value of the first preset voltage may be arbitrarily set according to the type of the actual external electrical device and the operating voltage.

First, a first voltage transmitted from the external power device, for example, an operating voltage at which the external power device is operating, is collected by the collection module 11. When the collected first voltage is less than the first preset voltage 161V, the comparing module 12 is turned off. For example, in practical applications, when the first voltage is smaller than the first preset voltage, the first voltage may be any value smaller than the first preset voltage. For example, the first voltage may be zero voltage, negative voltage, or other positive voltage less than the first predetermined voltage, and so on, which are not listed here. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

In summary, in the technical solution of this embodiment, the on-off module 14 may be turned off when the working voltage of the external electrical device is detected to be lower than the first preset voltage, so that the voltage protection circuit may disconnect the connection between the external electrical device and the external power supply device, and achieve an effect of protecting the external electrical device when the first voltage is lower than the first preset voltage. Moreover, the circuit structure in the embodiment is simple, low in cost and easy to popularize and use.

Optionally, in practical applications, another embodiment of the present application may further define that the first voltage is greater than the second preset voltage. Specifically, the comparison module 12 compares the first voltage with a second preset voltage, and when the first voltage is greater than the second preset voltage, the comparison module 12 is turned on, when the comparison module 12 is turned on, the driving module 13 is turned on, and when the driving module 13 is turned on, the on-off module 14 is turned on. The second preset voltage is greater than the first preset voltage. For example, in an actual design process, the second preset voltage may be designed to be 180V, but it should be understood that the second preset voltage is not limited to be 180V in the embodiment of the present application, and the value of the second preset voltage may be arbitrarily set according to the type of the actual external power consumption device and the operating voltage.

In the technical scheme of this embodiment, the on-off module 14 may be turned on when it is detected that the working voltage of the external electrical device is greater than the second preset voltage, so that after the connection between the external electrical device and the external power supply device is disconnected, the voltage protection circuit may further turn on the connection between the external electrical device and the external power supply device when it is detected that the working voltage of the external electrical device is greater than the second preset voltage, so as to enable the external electrical device to normally work.

In practical applications, when the external power consumption device needs to work, 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. It is further worth mentioning that, in the above embodiment, when the first voltage is less than the first preset voltage 161V, the voltage protection circuit disconnects the external power consumption device from the external power supply device; when the first voltage is larger than 180V, the voltage protection circuit conducts the connection between the external electric equipment and the external power supply equipment.

For example, when the external power consumption device is connected to the external power supply device, if the first voltage is less than the first preset voltage 161V, the voltage protection circuit according to the above embodiment disconnects the external power consumption device from the external power supply device. And with the change of the first voltage, if the first voltage is gradually increased but the first voltage is less than or equal to 180V, the voltage protection circuit does not perform any operation, and the external power consumption equipment is still disconnected with the external power supply equipment. When the first voltage continues to increase to be greater than 180V, the voltage protection circuit conducts the connection of the external power consumption device and the external power supply device.

Or, when the external power consumption device is connected to the external power supply device, if the first voltage is greater than the second preset voltage by 180V, the voltage protection circuit according to the above embodiment turns on the connection between the external power consumption device and the external power supply device. And with the change of the first voltage, if the first voltage is gradually reduced, but the first voltage is greater than or equal to 161V, the voltage protection circuit does not execute any operation, and the connection between the external electric equipment and the external power supply equipment is still conducted. When the first voltage continues to decrease to less than 161V, the voltage protection circuit disconnects the external powered device from the external power supply device.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a voltage protection circuit according to some embodiments of the present disclosure. The present embodiment includes the following technical features in addition to the technical solution of any one of the above embodiments:

as shown in fig. 2, the voltage protection circuit further includes a power module 21. The power module 21 converts the first voltage collected by the collection module 11 into a second voltage, and transmits the second voltage to the driving module 13, the comparison module 12 and the on-off module 14, respectively. The power module 21 is used to provide the second voltage for the driving module 13, the comparing module 12 and the on-off module 14 to operate normally. The value of the second voltage is smaller than that of the first voltage, and the second voltage is direct current voltage. For example, the first voltage collected by the collection module 11 is usually an ac voltage, and the voltage value is relatively high. The operating voltage of the driving module 13, the comparing module 12 and the switching module 14 is usually dc voltage, and the voltage value is relatively low. Therefore, the collected first voltage is converted into the second voltage by the power module 21, so that the second voltage is a direct current voltage that meets the requirements of the operation of the driving module 13, the comparing module 12 and the on-off module 14. The reliability of normal operation of the driving module 13, the comparing module 12 and the on-off module 14 can be improved.

Referring to fig. 2 and 3, fig. 3 is a schematic circuit diagram of a voltage protection circuit according to some embodiments of the present disclosure. The present embodiment includes the following technical features in addition to the technical solution of any one of the above embodiments:

as shown in fig. 2 and 3, the driving module 13 includes: the circuit comprises a first triode VT1, a first resistor R1 and a field effect transistor Q1; the base electrode of the first triode VT1 is electrically connected to the comparison module 12, the emitter electrode of the first triode VT1 is connected to the ground wire, the collector electrode of the first triode VT1 is electrically connected to the first end of the first resistor R1 and the gate electrode of the field effect transistor Q1, the second end of the first resistor R1 is connected to the drain electrode of the field effect transistor Q1 and is electrically connected to the power module 21; the source of the field effect transistor Q1 is electrically connected to the on/off module 14. The first transistor VT1 may be an NPN transistor.

Specifically, the on-off of the on-off module 14 can be controlled by the on-off of the field effect transistor Q1, and compared with the voltage resistance of the ordinary triode field effect transistor Q1, the on-off module 14 can be turned on for a long time by the field effect transistor Q1 through a large current, so that the external electric equipment can work for a long time.

The field effect transistor Q1 is an N-channel parasitic MOS transistor; and/or the first triode is an NPN triode. According to the scheme, the diodes of the N-channel parasitic MOS tubes can prevent the MOS tubes in the N-channel parasitic MOS tubes from being burnt out when the voltage of the N-channel parasitic MOS tubes is too large, and can also prevent the MOS tubes in the N-channel parasitic MOS tubes from being burnt out when the source electrodes and the drain electrodes of the N-channel parasitic MOS tubes are reversely connected.

In the present embodiment, the switching module 14 is a Coil 1. Coil1 has one end electrically connected to the source of fet Q1 and the other end connected to ground. For example, when Coil1 is on, the connection between the external power consumption device and the external power supply device is on, and when Coil1 is off, the connection between the external power consumption device and the external power supply device is off. Coil 1's cost is lower, and the working method is comparatively reliable, can reduce voltage protection circuit's cost to a certain extent, promotes voltage protection circuit's reliability.

In addition, the power module 21 includes a voltage dependent resistor RV1, a rectifier bridge DB1, and a first capacitor C1. Two input ends of the rectifier bridge DB1 are electrically connected to one end of the first capacitor C1 and the first end of the voltage dependent resistor RV1 respectively, a positive output end of the rectifier bridge DB1 is electrically connected to the drain electrode of the field effect transistor Q1, and a negative output end of the rectifier bridge DB1 is connected to the ground wire. The other end of the first capacitor C1 is electrically connected with the second end of the piezoresistor RV 1; two receiving ends are led out from the first end of the piezoresistor RV1 and the second end of the piezoresistor RV1 respectively, and the two receiving ends are used for being electrically connected with a live wire L and a zero wire N of external electric equipment respectively.

Specifically, the voltage dependent resistor RV1 can be used to ensure the normal power supply of the circuit at the rear stage of the voltage protection circuit when the first voltage is lower than a first preset voltage, such as 161V. And through the action of the voltage dependent resistor RV1, when the first voltage is greater than a second preset voltage such as 180V, energy is absorbed, so that the reliable operation of the subsequent circuit of the voltage protection circuit is ensured. The first capacitor C1 may step down the first voltage. The rectifier bridge DB1 can convert the ac signal into the dc signal, that is, the first voltage is converted into the second voltage by the first capacitor C1 and the rectifier bridge DB1, so as to provide the second voltage for the driving module 13, the comparing module 12 and the on-off module 14 to work normally.

Optionally, the power module 21 further includes a second capacitor C2; one end of the second capacitor C2 is electrically connected to the positive output terminal of the rectifier bridge DB1, and the other end is grounded. The second capacitor C2 may filter the voltage output by the rectifier bridge DB1, so that a later-stage circuit of the second capacitor C2 may obtain a smoother dc voltage, and further improve the reliability of the normal operation of the driving module 13, the comparing module 12, and the on-off module 14.

In this embodiment, the voltage protection circuit further includes a pull-up resistor R8. A first end of the pull-up resistor R8 is electrically connected to the acquisition module 11, and a second end of the pull-up resistor R8 is electrically connected to the collector of the second transistor VT 2. (ii) a The acquisition module 11 provides a pull-up voltage for the second transistor VT2 through the pull-up resistor R8, that is, the pull-up resistor R8 may provide a pull-up voltage for the collector of the second transistor VT2, so as to improve the stability of the normal operation of the second transistor VT 2.

Optionally, the acquisition module 11 includes a voltage reduction processing module; the voltage reduction processing module performs voltage reduction processing on the acquired first voltage to obtain a third voltage, outputs the third voltage to the comparison module 12, enables the third voltage to be smaller than the driving voltage of the comparison module when the first voltage is smaller than a first preset voltage, and enables the third voltage to be larger than the driving voltage of the comparison module when the first voltage is larger than a second preset voltage. The process of comparing the first voltage with the first preset voltage by the comparing module 12 includes: and comparing the first voltage converted into the third voltage with the driving voltage.

The comparing module 12 in this embodiment is a second transistor VT 2. The base electrode of the second triode VT2 is electrically connected to the acquisition module 11, the emitter electrode of the second triode VT2 is connected to the ground wire, and the collector electrode of the second triode VT2 is electrically connected to the base electrode of the first triode VT 1. The driving voltage of the comparing module 12 may be set to the turn-on voltage Vbe of the second transistor VT 2.

The comparing module 12 compares the first voltage with a first preset voltage, and when the first voltage is smaller than the first preset voltage, the comparing module 12 is turned off, specifically: the third voltage is less than the conduction voltage Vbe of the second transistor VT2 of the comparison module 12, and turns off the comparison module 12.

The comparison module 12 compares the first voltage with a second preset voltage, and when the first voltage is greater than the second preset voltage, the comparison module 12 is turned on, specifically: the third voltage is greater than the conduction voltage Vbe of the second transistor VT2 of the comparison module 12, and turns on the comparison module 12.

In summary, the third voltage and the base-on voltage Vbe of the second transistor VT2 can be compared in this embodiment. When the third voltage is less than Vbe, the second transistor VT2 is turned off, and when the third voltage is greater than Vbe, the second transistor VT2 is turned on.

It should be noted that the voltage reduction processing module of the present application includes: the temperature compensation circuit comprises a rectifier diode VD2, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a third capacitor C3 and a temperature compensation diode VD 3; the anode of the rectifier diode VD2 is used for being electrically connected with a live wire L of an external electric device so as to collect a first voltage; a cathode of the rectifying diode VD2 is electrically connected to a first end of the second resistor R2, a second end of the second resistor R2 is electrically connected to one end of the third capacitor C3, and the other end of the third capacitor C3 is connected to the ground; a first end of the third resistor R3 is electrically connected to a second end of the second resistor R2, and a second end of the third resistor R3 is electrically connected to a first end of the fourth resistor R4 and a first end of the fifth resistor R5, respectively; a second end of the fourth resistor R4 is grounded; a second end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6 and the comparison module 12, respectively, to output a third voltage to the comparison module 12; the second end of the sixth resistor R6 is electrically connected to the first end of the seventh resistor R7; the second end of the seventh resistor R7 is electrically connected to one end of the temperature compensation diode VD 3; the other end of the temperature compensating diode VD3 is grounded.

Specifically, half-wave rectification may be performed by the rectifying diode VD2, and the second voltage obtained by voltage reduction is obtained by the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7, and is used for comparison with the preset voltage of the comparing module 12. And the third capacitor C3 of the present embodiment may be filtered. Therefore, the scheme of this embodiment may enable the acquisition module 11 to transmit the relatively stable second voltage to the comparison module 12. In addition, the temperature compensation diode VD3 can perform temperature compensation on the comparison module 12 and the driving module 13, so as to improve the stability of the comparison module 12 and the driving module 13 during operation.

It should be noted that the first end of the pull-up resistor R8 of the present embodiment is electrically connected to the collection module 11 by being electrically connected to the second end of the third resistor R3.

Optionally, the voltage protection circuit further includes a voltage stabilizing module; the voltage stabilization module is electrically connected between the comparison module 12 and the acquisition module 11. In this embodiment, the voltage stabilizing module may provide a relatively stable voltage to the comparing module 12. The voltage stabilizing module is a voltage stabilizing diode VD 1; the anode of the voltage-stabilizing diode VD1 is electrically connected to the comparison module 12, and the cathode is electrically connected to the acquisition module 11. The voltage stabilizing diode VD1 can keep the voltage at the two ends of the voltage stabilizing diode VD1 balanced when the current passing through the voltage stabilizing diode VD1 changes in a large range, thereby realizing the voltage stabilizing function, and the cost of the voltage stabilizing diode VD1 is lower, so that the cost of the voltage protection circuit can be reduced to a certain extent.

The operation principle of the present embodiment is further described below with reference to fig. 3:

the voltage protection circuit of the present application may be used on an external powered device, which is commonly referred to in the art as a load. For example, in the present application, when the Coil1 in the voltage 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 magnitude of the alternating current is not limited, and the alternating current can be 230V or 220V, and the like, and in practical application, the magnitude of the alternating current can be determined according to the working voltage of the external electric equipment during normal working. When the external electrical equipment is connected to the live line L and the neutral line N of the alternating current, the voltage 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. When the N-channel parasitic MOS tube is electrified, the N-channel parasitic MOS tube is pulled up and conducted through the first resistor R1, namely the N-channel parasitic MOS tube is in a conducting state when the N-channel parasitic MOS tube is just electrified, and the voltage protection circuit can execute corresponding operation along with the access of external electric equipment to alternating current.

Specifically, surge absorption is performed by the varistor RV 1. When the input voltage at the two ends of the first pin J1 and the second pin J2 is greater than the second preset voltage ratio, such as the second preset voltage ratio, the internal resistance of the voltage dependent resistor RV1 is rapidly reduced, so as to clamp the input voltage, and energy is absorbed by the voltage dependent resistor RV1, thereby ensuring reliable operation of the subsequent stage circuit. When the input voltage at the two ends of the first pin J1 and the second pin J2 is smaller than the first preset voltage ratio, such as 161V, the internal resistance of the voltage dependent resistor RV1 is increased rapidly, and the normal power supply of the subsequent circuit is ensured. The input voltage at the two ends of the first pin J1 and the second pin J2 is reduced by the first capacitor C1 and then transmitted to the rectifier bridge DB 1. The rectifier bridge DB1 converts the alternating current into direct current. And then, filtering is performed through a second capacitor C2 to obtain a relatively smooth dc voltage, so that the smooth dc voltage can be used as a driving voltage of the Coil 1.

On the other hand, the voltage of the first pin J1 is half-wave rectified by the rectifying diode VD2, and is stepped down by the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 to obtain the third voltage, which is used for comparison with the conduction voltage Vbe of the second transistor VT2 (the conduction voltage Vbe of the second transistor VT2 refers to the driving voltage of the comparison module 12 provided in the above embodiment). Filtering is performed by a third capacitor C3. When the third voltage is less than Vbe, the second transistor VT2 is turned off, and when the third voltage is greater than Vbe, the second transistor VT2 is turned on.

The method comprises the following specific steps: when the first voltage collected by the sampling module is smaller than a first preset voltage ratio, such as 161V. The second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 are used for voltage reduction to obtain a third voltage. At this time, the third voltage is less than Vbe, and the second transistor VT2 is turned off. The first transistor VT1 is turned on when the second transistor VT2 is turned off. When the first transistor VT1 is turned on, the N-channel parasitic MOS transistor is turned off, and at this time, the Coil1 is turned off.

When the first voltage collected by the sampling module is greater than the second preset voltage ratio, such as 180V. The second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 are used for voltage reduction to obtain a third voltage. At this time, the third voltage is greater than Vbe, and the second transistor VT2 is turned on. When the second transistor VT2 is turned on, the first transistor VT1 is turned off. When the first transistor VT1 is turned off, i.e., turned off, the N-channel parasitic MOS transistor is turned on, and at this time, the Coil1 is turned on.

When the first voltage collected by the sampling module is greater than or equal to the first preset voltage ratio, such as 161V, and less than or equal to the second preset voltage ratio, such as 180V, the voltage protection circuit does not perform any operation, so that the Coil1 is kept in the existing state.

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 the embodiment, the voltage protection circuit can be used for disconnecting the on-off module 14 when the working voltage of the external electric device is detected to be lower than the first preset voltage, 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 lower than the first preset voltage. After the external electric equipment is disconnected from the external power supply equipment, when the voltage at which the external electric equipment works is higher than a second preset voltage, the connection between the external electric equipment and the external power supply equipment can be automatically conducted, so that the external electric equipment works normally. 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 external power consumption device and the voltage protection circuit of any of the above embodiments; the external electric equipment is electrically connected with the acquisition module; when the on-off module is disconnected, the external power utilization equipment is disconnected with the external power supply equipment; when the on-off 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 voltage protection circuit of any one of the above embodiments, this embodiment can disconnect the on-off module when detecting that the working voltage of the external power consumption device is lower than the first preset voltage through the voltage protection circuit, so as to disconnect the connection between the external power consumption device and 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 lower than the first preset voltage. In this embodiment, after the external electrical device is disconnected from the external power supply device, when the operating voltage at which the external electrical device is operating is greater than the second preset voltage, the connection between the external electrical device and the external power supply device may be automatically turned on, so that the external electrical device operates normally.

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; these modifications and substitutions do not depart from the spirit of the embodiments of the present application, and they should be construed as being included in the scope of the claims and description of the present application. 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 rather to cover all embodiments falling within the scope of the appended claims.

Claims (14)

1. A voltage protection circuit, comprising: the device comprises an acquisition module, a comparison module, a driving module and an on-off module;

the acquisition module acquires a first voltage transmitted to the acquisition module by external electric equipment and transmits the first voltage to the comparison module;

the comparison module compares the first voltage with a first preset voltage, and is disconnected when the first voltage is smaller than the first preset voltage, the drive module is disconnected when the comparison module is disconnected, and the on-off module is disconnected when the drive module is disconnected;

wherein the first preset voltage is a positive number;

the voltage protection circuit further comprises a power module;

the power supply module converts the first voltage acquired by the acquisition module into a second voltage, and transmits the second voltage to the driving module, the comparison module and the on-off module respectively so as to provide the second voltage for enabling the driving module, the comparison module and the on-off module to work normally;

the value of the second voltage is smaller than that of the first voltage, and the second voltage is direct-current voltage.

2. The voltage protection circuit of claim 1, wherein the comparison module compares the first voltage with a second preset voltage, and is turned on when the first voltage is greater than the second preset voltage, the comparison module is turned on when the comparison module is turned on, and the on-off module is turned on when the drive module is turned on; the second preset voltage is greater than the first preset voltage.

3. The voltage protection circuit of claim 1, wherein the driving module comprises: the first triode, the first resistor and the field effect transistor;

the base electrode of the first triode is electrically connected with the comparison module, the emitter electrode of the first triode is grounded, the collector electrode of the first triode is respectively and electrically connected with the first end of the first resistor and the grid electrode of the field effect tube, and the second end of the first resistor is connected with the drain electrode of the field effect tube and is electrically connected with the power supply module; and the source electrode of the field effect transistor is electrically connected with the on-off module.

4. The voltage protection circuit of claim 3, wherein the field effect transistor is an N-channel parasitic MOS transistor;

and/or the first triode is an NPN triode.

5. The voltage protection circuit of claim 3, wherein the switching module is a coil;

one end of the coil is electrically connected to the source electrode of the field effect transistor, and the other end of the coil is grounded.

6. The voltage protection circuit of claim 3, wherein the power module comprises a voltage dependent resistor, a rectifier bridge, and a first capacitor;

two input ends of the rectifier bridge are electrically connected to one end of the first capacitor and the first end of the piezoresistor respectively, a positive output end of the rectifier bridge is electrically connected to a drain electrode of the field effect transistor, and a negative output end of the rectifier bridge is grounded;

the other end of the first capacitor is electrically connected with the second end of the piezoresistor;

two receiving ends are led out from the first end of the piezoresistor and the second end of the piezoresistor respectively, and the two receiving ends are used for being electrically connected with a live wire and a zero line of external electric equipment respectively.

7. The voltage protection circuit of claim 6, wherein the power module further comprises a second capacitor;

one end of the second capacitor is electrically connected to the positive output end of the rectifier bridge, and the other end of the second capacitor is grounded.

8. The voltage protection circuit of claim 3, wherein the comparison module is a second transistor;

the base electrode of the second triode is electrically connected with the acquisition module, the emitting electrode of the second triode is grounded, and the collecting electrode of the second triode is electrically connected with the base electrode of the first triode.

9. The voltage protection circuit of claim 8, further comprising a pull-up resistor;

the first end of the pull-up resistor is electrically connected to the acquisition module, and the second end of the pull-up resistor is electrically connected to the collector of the second triode; the acquisition module provides pull-up voltage for the second triode through the pull-up resistor.

10. The voltage protection circuit of claim 2, wherein the acquisition module comprises a buck processing module;

the voltage reduction processing module is used for carrying out voltage reduction processing on the collected first voltage to obtain a third voltage, outputting the third voltage to the comparison module, enabling the third voltage to be smaller than the driving voltage of the comparison module when the first voltage is smaller than the first preset voltage, and enabling the third voltage to be larger than the driving voltage of the comparison module when the first voltage is larger than the second preset voltage;

the process of comparing the first voltage with a first preset voltage by the comparison module comprises the following steps:

comparing the first voltage converted into the third voltage with the driving voltage.

11. The voltage protection circuit of claim 10, wherein the buck processing module comprises: the temperature compensation circuit comprises a rectifier diode, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor and a temperature compensation diode;

the anode of the rectifier diode is used for being electrically connected with a live wire of the external electric equipment so as to collect the first voltage; a negative electrode of the rectifier diode is electrically connected to a first end of the second resistor, a second end of the second resistor is electrically connected to one end of the third capacitor, and the other end of the third capacitor is grounded;

the first end of the third resistor is electrically connected to the second end of the second resistor, and the second end of the third resistor is electrically connected to the first end of the fourth resistor and the first end of the fifth resistor respectively;

the second end of the fourth resistor is connected with the ground wire;

a second end of the fifth resistor is electrically connected to the first end of the sixth resistor and the comparison module respectively, so as to output the third voltage to the comparison module;

the second end of the sixth resistor is electrically connected to the first end of the seventh resistor;

a second end of the seventh resistor is electrically connected to one end of the temperature compensation diode;

the other end of the temperature compensation diode is connected with the ground wire.

12. The voltage protection circuit according to claim 1 or 2, further comprising a voltage stabilization module;

the voltage stabilizing module is electrically connected between the comparing module and the collecting module.

13. The voltage protection circuit of claim 12, wherein the voltage regulation module is a zener diode;

and the anode of the voltage stabilizing diode is electrically connected with the comparison module, and the cathode of the voltage stabilizing diode is electrically connected with the acquisition module.

14. An electric device comprising an external electric device and the voltage protection circuit according to any one of claims 1 to 13;

the external electric equipment is electrically connected with the acquisition module;

when the on-off module is disconnected, the external power utilization equipment is disconnected with the external power supply equipment;

and when the on-off module is switched on, the connection between the external electric equipment and the external power supply equipment is switched on.

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