Electrostatic interference detection circuit and ammeter

Abstract

The utility model relates to the technical field of intelligent electric meters, and discloses an electrostatic interference detection circuit and an electric meter, the electrostatic interference detection circuit comprises a charge processing circuit and a signal trigger, the input end of the charge processing circuit collects electrostatic charges of the detection end of the electric meter, and the output end of the charge processing circuit is connected with the input end of the signal trigger; the voltage conversion module is used for converting the electrostatic charges into voltage signals; the power supply end of the signal trigger is connected with the first power supply; the electric meter comprises an electric meter body, a charge processing circuit and a signal trigger. The electric meter can detect electrostatic interference events, the electricity stealing phenomenon caused by electrostatic interference is avoided, and the charge processing circuit and the signal trigger are simple in structure and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of smart meters, and particularly relates to an electrostatic interference detection circuit and an electric meter. Background Art

[0002] With the economic development, the electricity consumption continues to increase. It often occurs that the normal operation of the electric energy meter is interfered by strong electrostatic devices, resulting in frequent electricity theft. Therefore, while improving the electrostatic protection design of the electric energy meter, it is also necessary to add a function to detect electrostatic events to the electric meter. Summary of the Utility Model

[0003] Therefore, the technical problem to be solved by the utility model is to solve the problem that the existing electric meter does not have the function of electrostatic detection, so as to provide an electrostatic interference detection circuit and an electric meter.

[0004] To achieve the above object, the utility model provides the following technical solutions:

[0005] In the first aspect, the utility model provides an electrostatic interference detection circuit, which is applied to an electric meter. The electrostatic interference detection circuit includes: a charge processing circuit and a signal trigger. Among them, for the charge processing circuit, its input end collects static charges at the detection end of the electric meter, its output end is connected to the input end of the signal trigger, and it is used to convert static charges into voltage signals; for the signal trigger, its power supply end is connected to the first power supply; when the charge processing circuit collects static charges and the voltage signal is greater than the conduction voltage drop of the signal trigger, the signal trigger switches its switch state and outputs a first level signal, and the first level signal indicates that the electric meter is interfered by static electricity.

[0006] For the electrostatic interference detection circuit provided by the utility model, which is applied to an electric meter, the magnitude of the voltage signal reflects the quantity of static charges. The signal trigger can switch its on-off state based on the magnitude of the voltage signal. When the static charges exceed a certain quantity, the voltage signal increases at this time, causing the signal trigger to switch its switch state and output a first level signal, indicating that the electric meter is interfered by static electricity, thereby realizing the detection of electrostatic interference on the electric meter. Moreover, the electrostatic interference detection circuit only includes a charge processing circuit and a signal trigger, and the circuit structure is simple and easy to manufacture.

[0007] In an optional implementation manner, the charge processing circuit includes: a signal collector and a signal amplifier. Among them, for the signal collector, its input end collects static charges, its output end is connected to the input end of the signal amplifier, and its first end is connected to the first end of the signal amplifier and then grounded, and it is used to convert static charges into an initial voltage signal; for the signal amplifier, its first power supply end is connected to the first power supply, its second power supply end is connected to the second power supply, its output end is connected to the input end of the signal trigger, and it is used to amplify the initial voltage signal and then output a voltage signal; the first power supply and the second power supply are equal in magnitude and opposite in direction.

[0008] For the electrostatic interference detection circuit provided by the present utility model, since the static charges collected by the signal collector include positive charges and negative charges, the initial voltage signal includes an initial positive voltage signal and an initial negative voltage signal. Under the action of the first power supply and the second power supply with equal magnitudes and opposite directions, the signal amplifier can amplify the initial positive voltage signal and the initial negative voltage signal respectively.

[0009] In an optional embodiment, the signal collector includes: a storage circuit and a first clamping circuit. Wherein, the first end of the storage circuit and the first clamping circuit connected in parallel is connected to the first end of the signal amplifier, and the second end of the storage circuit and the first clamping circuit connected in parallel is connected to the input end of the signal amplifier; the first clamping circuit is used to suppress the voltage at the input end of the signal amplifier; the storage circuit is used to generate a voltage signal after storing static charges.

[0010] In an optional embodiment, the signal amplifier includes: a first voltage dividing circuit and an amplifying circuit. Wherein, for the amplifying circuit, its input end is connected to the output end of the signal collector, its output end is connected to the second end of the first voltage dividing circuit and the input end of the signal trigger to output a voltage signal, its first end is connected to the third end of the first voltage dividing circuit, its first power supply end is connected to the first power supply, its second power supply end is connected to the second power supply, and it is used to amplify the initial voltage signal based on the first power supply and the second power supply and then output a voltage signal; for the first voltage dividing circuit, its third end is connected to the output end of the signal collector, and the intensity of the voltage signal is adjusted by adjusting the ratio of the resistance values inside the first voltage dividing circuit.

[0011] In an optional embodiment, the signal amplifier further includes: a power conversion circuit, its input end is connected to the first power supply and the first power supply end of the amplifying circuit, its output end is connected to the second power supply end of the amplifying circuit, and it is used to convert the first power supply into the second power supply.

[0012] In an optional embodiment, the signal trigger includes: a first trigger unit and a second trigger unit. Wherein, for the first trigger unit, its control end is connected to the output end of the charge processing circuit and the first end of the second trigger unit, its first end is connected to the control end of the second trigger unit, and its second end is connected to the second end of the second trigger unit; when the voltage signal is positive and the voltage signal is greater than the conduction voltage drop of the first trigger unit, after the first trigger unit conducts and the second trigger unit turns off, the second end of the first trigger unit outputs a first level signal; when the voltage signal is negative and the absolute value of the voltage signal is greater than the conduction voltage drop of the second trigger unit, after the second trigger unit conducts and the first trigger unit turns off, the second end of the second trigger unit outputs a first level signal.

[0013] The electrostatic interference detection circuit provided by the present utility model respectively uses a first trigger unit to detect the magnitude of a positive voltage signal and a second trigger unit to detect the magnitude of a negative voltage signal, and detects the magnitudes of the positive and negative voltage signals through two independent channels, avoiding mutual interference between the positive and negative voltage signals and improving the accuracy of the first level signal output by the signal trigger.

[0014] In an alternative embodiment, the first trigger unit includes: a first switch, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor. Among them, for the first resistor, its first end is connected to the output end of the charge processing circuit, and its second end is connected to the control end of the first switch and the first end of the second resistor; for the second resistor, its second end is grounded after being connected to the first end of the first switch, the control end of the second trigger unit and the first end of the first capacitor; for the first switch, its second end is connected to the first end of the third resistor and the first end of the fourth resistor; for the third resistor, its second end is connected to the first power supply; for the fourth resistor, its second end is connected to the second end of the first capacitor and the second end of the second trigger unit; when the voltage signal is positive and the voltage signal is greater than the conduction voltage drop of the first switch, after the first switch conducts and the second trigger unit turns off, the second end of the first switch outputs a first level signal through the fourth resistor.

[0015] In an alternative embodiment, the second trigger unit includes: a first switch circuit and a second switch circuit. Among them, for the first switch circuit, its first end is connected to the output end of the charge processing circuit, its control end is connected to the first end of the first switch, its second end is connected to the first power supply, and its third end is connected to the control end of the second switch circuit; for the second switch circuit, its first end is connected to the first power supply, its second end is connected to the second end of the first trigger unit, and its third end is grounded; when the voltage signal is negative and the absolute value of the voltage signal is greater than the conduction voltage drop of the first switch circuit, after the first switch circuit conducts and the second switch circuit conducts, the second end of the second switch circuit outputs a first level signal.

[0016] In an alternative embodiment, the signal trigger further includes: a second clamping circuit, whose first end and second end are respectively connected to the second end of the first trigger unit and the third end of the second trigger unit, and is used to suppress the voltage output by the second ends of the first trigger unit and the second trigger unit.

[0017] In a second aspect, the present utility model provides an electric meter, which includes an electric meter body and the electrostatic interference detection circuit of the first aspect. Among them, the input end of the charge processing circuit collects the static charges on the inner surface of the housing of the electric meter body; the input end of the control system in the electric meter body is connected to the output end of the signal trigger; when the charge processing circuit collects static charges and the voltage signal corresponding to the static charges is greater than the conduction voltage drop of the signal trigger, after the signal trigger switches the switch state and outputs a first level signal, the control system records an electrostatic interference event of the electric meter body once.

[0018] For the electric meter provided by the present utility model, the magnitude of the voltage signal reflects the quantity of the static charges on the inner surface of the housing of the electric meter body. The signal trigger can switch its on-off state based on the magnitude of the voltage signal. When the static charges exceed a certain quantity, the voltage signal increases at this time, causing the signal trigger to switch the switch state and output a first level signal, indicating that the electric meter body is subject to electrostatic interference, thereby realizing the detection of electrostatic interference on the inner surface of the housing of the electric meter body. Moreover, the electrostatic interference detection circuit only includes a charge processing circuit and a signal trigger, and the structure of the electric meter is simple and easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a composition diagram of a specific example of the electrostatic interference detection circuit according to an embodiment of the present utility model;

[0021] Figure 2 It is a composition diagram of another specific example of the electrostatic interference detection circuit according to an embodiment of the present utility model;

[0022] Figure 3 It is a structural diagram of a specific circuit of the charge processing circuit according to an embodiment of the present utility model;

[0023] Figure 4 It is a structural diagram of a specific circuit of the power conversion circuit according to an embodiment of the present utility model;

[0024] Figure 5 It is a structural diagram of a specific circuit of the signal trigger according to an embodiment of the present utility model;

[0025] Figure 6 It is a composition diagram of a specific example of the electric meter according to an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0027] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0029] In addition, the technical features involved in different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0030] In the related art, electric meters generally do not have an electrostatic detection function. Therefore, when too much static charge accumulates on the surface of the electric meter or there is strong electrostatic interference around the electric meter, the electric meter cannot record and upload the above electrostatic interference events, resulting in the inability of the operator to monitor abnormal working conditions of the electric meter or phenomena such as electricity theft. To solve the above problems,

[0031] This embodiment provides an electrostatic interference detection circuit 1, as Figure 1 shown, which is applied to an electric meter. The electrostatic interference detection circuit 1 includes: a charge processing circuit 11 and a signal trigger 12. Among them, for the charge processing circuit 11, its input end collects the static charge of the detection end of the electric meter, its output end is connected to the input end of the signal trigger 12, and it is used to convert the static charge into a voltage signal; for the signal trigger 12, its power supply end is connected to the first power supply VCC.

[0032] Specifically,Figure 1 In this case, when there is static charge on the surface of the electricity meter or there is strong electrostatic interference around the electricity meter, static charge accumulates at the detection end of the electricity meter. After the static charge generates an electric potential when accumulating at the input end of the charge processing circuit 11, the charge processing circuit 11 outputs a voltage signal according to the electric potential at the input end.

[0033] Optionally, the charge processing circuit 11 may include a device for collecting static charge, such as a conductive device like a metal plate, and may also include relevant circuit structures for amplifying the electric potential, so as to increase the level of the output voltage signal, and further improve the sensitivity of the electrostatic interference detection circuit 1.

[0034] Figure 1 In this case, when the charge processing circuit 11 collects static charge and the voltage signal is greater than the conduction voltage drop of the signal trigger 12, the signal trigger 12 switches the switch state and outputs a first-level signal, and the first-level signal characterizes that the electricity meter is affected by electrostatic interference.

[0035] Exemplarily, the signal trigger 12 may be composed of switching transistors such as triodes, MOS transistors, and IGBTs. When the amount of static charge on the surface of the electricity meter is different, the signal trigger 12 has the following two output states:

[0036] (1) When the static charge on the surface of the electricity meter accumulates to a certain value, the voltage signal output by the charge processing circuit 11 will exceed the conduction voltage drop of the switching transistor inside the signal trigger 12. At this time, the corresponding switching transistor inside the signal trigger 12 switches to the conducting state, so that the signal trigger 12 outputs a first-level signal to the server, and the operator can remotely view the electrostatic interference situation of the electricity meter at the terminal and troubleshoot the fault in time.

[0037] (2) When there is no static charge accumulation or less static charge accumulation on the surface of the electricity meter, the voltage signal output by the charge processing circuit 11 will not exceed the conduction voltage drop of the switching transistor inside the signal trigger 12, and all the switching transistors inside the signal trigger 12 are in the off state, so that the signal trigger 12 outputs a second-level signal opposite to the first-level signal to the server, and the operator can leave it without treatment.

[0038] It should be noted that when the signal trigger 12 outputs the first-level signal and the second-level signal, its specific internal switch state is determined by the circuit structure and is not limited here.

[0039] The electrostatic interference detection circuit provided in this embodiment is applied to an electric meter. The magnitude of the voltage signal reflects the quantity of static charges. The signal trigger can switch its on / off state based on the magnitude of the voltage signal. When the static charges exceed a certain quantity, the voltage signal increases at this time, causing the signal trigger to switch its switch state and output a first-level signal, indicating that the electric meter is subject to electrostatic interference, thereby realizing the detection of electrostatic interference on the electric meter. Moreover, the electrostatic interference detection circuit only includes a charge processing circuit and a signal trigger, with a simple circuit structure and easy production.

[0040] In some alternative embodiments, as Figure 2 shown, the charge processing circuit 11 includes: a signal collector 111 and a signal amplifier 112. Among them, for the signal collector 111, its input terminal collects static charges, its output terminal is connected to the input terminal of the signal amplifier 112, and its first terminal is grounded after being connected to the first terminal of the signal amplifier 112. It is used to convert static charges into an initial voltage signal; for the signal amplifier 112, its first power supply terminal is connected to the first power supply VCC, its second power supply terminal is connected to the second power supply -VCC, and its output terminal is connected to the input terminal of the signal trigger 12. It is used to amplify the initial voltage signal and then output a voltage signal; the first power supply VCC and the second power supply -VCC are equal in magnitude and opposite in direction.

[0041] Specifically, Figure 2 in, the signal collector 111 is used to collect the static charges at the detection end of the electric meter and generate an initial voltage signal after generating an electric potential inside it. To prevent the initial voltage signal from being much smaller than the conduction voltage drop of the signal trigger 12, resulting in the signal trigger 12 being unable to make an action feedback on the initial voltage signal, the signal amplifier 112 amplifies the initial voltage signal by a fixed multiple and then outputs the voltage signal to the signal trigger 12, making it possible for the output voltage signal to be greater than the conduction voltage drop of the signal trigger 12, thereby improving the sensitivity of the electrostatic interference detection circuit 1.

[0042] In some alternative embodiments, as Figure 3 shown, the signal collector 111 includes: a storage circuit 1111 and a first clamping circuit 1112. Among them, the first terminal of the storage circuit 1111 and the first clamping circuit 1112 after being connected in parallel is connected to the first terminal of the signal amplifier 112, and the second terminal of the storage circuit 1111 and the first clamping circuit 1112 after being connected in parallel is connected to the input terminal of the signal amplifier 112; the first clamping circuit 1112 is used to suppress the voltage at the input terminal of the signal amplifier 112; the storage circuit 1111 is used to store static charges and then generate a voltage signal.

[0043] Specifically, Figure 3In it, the storage circuit 1111 is composed of a resistor R1 and a capacitor C1. When static charges accumulate at the detection end of the ammeter, after the upper and lower plates of the capacitor C1 store the static charges, a potential difference is generated between the upper and lower plates of the capacitor C1 and input to the input end of the signal amplifier 112.

[0044] Optionally, the first clamping circuit 1112 is a Transient Voltage Suppressor (TVS), which is used to suppress the potential difference within a preset range to protect the components in the signal amplifier 112 from damage. The specific structure of the first clamping circuit 1112 is not limited here.

[0045] In some alternative embodiments, such as Figure 3 shown, the signal amplifier 112 includes: a first voltage dividing circuit 1121 and an amplifying circuit 1122. Among them, for the amplifying circuit 1122, its input end is connected to the output end of the signal collector 111, its output end (i.e., the end that outputs the Signal signal) is connected to the second end of the first voltage dividing circuit 1121 and the input end of the signal trigger 12 and then outputs a voltage signal. Its first end is connected to the third end of the first voltage dividing circuit 1121. Its first power supply end is connected to the first power supply VCC, and its second power supply end is connected to the second power supply -VCC. It is used to amplify the initial voltage signal based on the first power supply VCC and the second power supply -VCC and then output a voltage signal; for the first voltage dividing circuit 1121, its third end is connected to the output end of the signal collector 111, and by adjusting the ratio of the resistance values of the internal resistors of the first voltage dividing circuit 1121, the intensity of the voltage signal is adjusted.

[0046] Exemplarily, Figure 3 in it, the first voltage dividing circuit 1121 is composed of a resistor R4 and a resistor R5 connected in series, and a capacitor C4 connected in parallel with the resistor R5. The amplifying circuit 1122 includes a control chip U1 powered by the first power supply VCC and the second power supply -VCC and having an amplifying function, and a voltage dividing and filtering circuit composed of resistors R2, R3, capacitors C2, and C3.

[0047] Specifically, Figure 3 in it, since the static charges collected by the signal collector 111 include positive charges and negative charges, the initial voltage signal output by the signal collector 111 may be positive or negative. The control chip U1 in the amplifying circuit 1122 can amplify the initial positive voltage signal and the initial negative voltage signal respectively under the action of the first power supply VCC and the second power supply -VCC and then output a voltage signal. To improve the flexibility of the detection circuit, by adjusting the ratio of the resistors R4 and R5 in the first voltage dividing circuit 1121, the voltage division degree of the output voltage is adjusted, and further the intensity of the voltage signal Signal input to the signal trigger 12 is adjusted.

[0048] Specifically, Figure 4 In the signal amplifier 112, there is also included: a power conversion circuit 1123. Capacitors C6 and C7 are used for filtering. U2 is a mature power conversion chip in the prior art. Its input terminal is connected to the first power supply VCC and the first power supply terminal of the amplification circuit 1122, and its output terminal is connected to the second power supply terminal of the amplification circuit 1122. It is used to convert the first power supply into the second power supply.

[0049] In some alternative embodiments, such as Figure 5 As shown, the signal trigger 12 includes: a first trigger unit 121 and a second trigger unit 122. Among them, for the first trigger unit 121, its control terminal is connected to the output terminal of the charge processing circuit 11 and the first terminal of the second trigger unit 122, its first terminal is connected to the control terminal of the second trigger unit 122, and its second terminal is connected to the second terminal of the second trigger unit 122.

[0050] Specifically, the second terminals of the first trigger unit 121 and the second trigger unit 122 output the JD_INT_MCU signal. When the voltage signal Signal is positive and the voltage signal Signal is greater than the conduction voltage drop of the first trigger unit 121, after the first trigger unit 121 conducts and the second trigger unit 122 turns off, the JD_INT_MCU signal output from the second terminal of the first trigger unit 121 is the first level signal; when the voltage signal Signal is negative and the absolute value of the voltage signal Signal is greater than the conduction voltage drop of the second trigger unit 122, after the second trigger unit 122 conducts and the first trigger unit 121 turns off, the JD_INT_MCU signal output from the second terminal of the second trigger unit 122 is the first level signal.

[0051] Exemplarily, Figure 5 In this embodiment, when both the first trigger unit 121 and the second trigger unit 122 are cutoff, the JD_INT_MCU signal is a high-level signal. When any one of the first trigger unit 121 and the second trigger unit 122 conducts, the JD_INT_MCU signal jumps to a low-level signal, that is, the first level signal is a low-level signal. An operator can determine whether the static charge on the meter surface has accumulated to a certain value resulting in an electrostatic interference phenomenon by detecting whether there is a first level signal.

[0052] In some alternative embodiments, such as Figure 5As shown in the figure, the first trigger unit 121 includes: a first switch V1, a first resistor R6, a second resistor R9, a third resistor R7, a fourth resistor R8, and a first capacitor C8. Among them, for the first resistor R6, its first end (i.e., the end receiving the Signal signal) is connected to the output end of the charge processing circuit 11, and its second end is connected to the control end of the first switch V1 and the first end of the second resistor R9; for the second resistor R9, its second end is grounded after being connected to the first end of the first switch V1, the control end of the second trigger unit 122, and the first end of the first capacitor C8; for the first switch V1, its second end is connected to the first end of the third resistor R7 and the first end of the fourth resistor R8; for the third resistor R7, its second end is connected to the first power supply VCC; for the fourth resistor R8, its second end is connected to the second end of the first capacitor C8 and the second end of the second trigger unit 122.

[0053] Specifically, Figure 5 When the voltage signal Signal is positive and the voltage signal Signal is less than the conduction voltage drop of the first switch V1, after the first switch V1 remains in the cut-off state and the second trigger unit 122 is turned off, the voltage of the first power supply VCC passes through the third resistor R7 and the fourth resistor R8, making JD_INT_MCU at a high level, that is, the second level signal; when the voltage signal Signal is positive and the voltage signal Signal is greater than the conduction voltage drop of the first switch V1, after the first switch V1 conducts and the second trigger unit 122 is turned off, the first power supply VCC is grounded through the third resistor R7 and the first switch V1, making the voltage at the second end of the first switch 0, thereby making JD_INT_MCU at a low level, that is, the first level signal.

[0054] In some optional embodiments, the second trigger unit 122 includes: a first switch circuit 1221 and a second switch circuit 1222. Among them, for the first switch circuit 1221, its first end (i.e., the end receiving the Signal signal) is connected to the output end of the charge processing circuit 11, its control end is connected to the first end of the first switch V1, its second end is connected to the first power supply VCC, and its third end is connected to the control end of the second switch circuit 1222; for the second switch circuit 1222, its first end is connected to the first power supply VCC, its second end is connected to the second end of the first trigger unit 121, and its third end is grounded.

[0055] Exemplarily, Figure 5 In it, the first switch circuit 1221 includes a second switch V2 and resistors R10 - R13, and the second switch circuit 1222 includes a third switch V3 and resistors R14 - R16.

[0056] Specifically, Figure 5When the voltage signal Signal is negative and the absolute value of the voltage signal Signal is less than the conduction voltage drop of the second switching circuit 1222, the second switch V2 is turned off. The first power supply VCC makes the level of the FAN_S terminal high through the resistors R10 and R11. At this time, the third switch V3 remains in the off state under the control of the high level. After the voltage of the first power supply VCC passes through R15 and R16, JD_INT_MCU becomes high level, that is, the second level signal.

[0057] Specifically, Figure 5 When the voltage signal Signal is negative and the absolute value of the voltage signal Signal is greater than the conduction voltage drop of the second switching circuit 1222, the second switch V2 is turned on, causing the first power supply VCC to be grounded through the resistors R10 and the second switch V2, so that the level of the FAN_S terminal changes from high to low. Since this low signal is less than 0V, if it is directly output, the subsequent circuit cannot recognize it. Therefore, by introducing the second switching circuit 1222, when this low signal is less than 0V, the third switch V3 is turned on, causing the first power supply VCC to be grounded through the resistors R15 and the third switch V3, so that JD_INT_MCU jumps to a low level, that is, the first level signal.

[0058] Specifically, Figure 5 In, the signal trigger 12 further includes: a second clamping circuit 123, whose first end and second end are respectively connected to the second end of the first trigger unit 121 and the third end of the second trigger unit 122, and is used to suppress the voltage of the outputs of the first trigger unit 121 and the third end of the second trigger unit 122.

[0059] It should be noted that the first switch V1 and the second switch V2 in the signal trigger of this embodiment are both NPN-type triodes, and the third switch V3 is a PNP-type triode. Those skilled in the art can also set the types and connection relationships of each switch according to actual needs. As long as the structure of the signal trigger 12 can switch the output state under the action of positive and negative input voltages of a preset size, it falls within the protection scope of this embodiment.

[0060] This embodiment provides an electric meter, as Figure 6 shown, including an electric meter body 2 and the electrostatic interference detection circuit 1 of the above embodiment and any of its optional implementation manners. Among them, the input end of the charge processing circuit 11 collects the static charges on the inner surface of the housing of the electric meter body 2; the input end of the control system 21 in the electric meter body 2 is connected to the output end of the signal trigger 12; when the charge processing circuit 11 collects static charges and the voltage signal corresponding to the static charges is greater than the conduction voltage drop of the signal trigger 12, after the signal trigger 12 switches the switch state and outputs the first level signal, the control system 21 records an electrostatic interference event of the electric meter body 2 once.

[0061] Specifically, Figure 6 In Figure 6 , the input end of the charge processing circuit 11 is connected to the inner surface of the housing of the meter body 2. It collects the static charges on the inner surface. After the static charges accumulate in the charge processing circuit 11 to generate an electric potential, the charge processing circuit 11 outputs a voltage signal. Then, the signal trigger 12 and the control system 21 have the following two output states according to the magnitude of the voltage signal:

[0062] (1) When the static charges on the inner surface of the housing of the meter body 2 do not accumulate or accumulate less in the charge processing circuit 11, the voltage signal output by the charge processing circuit 11 will not exceed the conduction voltage drop of the switching tube inside the signal trigger 12. All the switching tubes in the signal trigger 12 are in the off state, so that the signal trigger 12 maintains the output of the second-level signal to the control system 21. The control system 21 does not record the static interference event of the meter, and the operator can leave it unprocessed.

[0063] (2) When the static charges on the inner surface of the housing of the meter body 2 accumulate to a certain value in the charge processing circuit 11, the voltage signal output by the charge processing circuit 11 will exceed the conduction voltage drop of the switching tube inside the signal trigger 12. At this time, the corresponding switching tube in the signal trigger 12 switches to the on state, so that the signal trigger 12 outputs the first-level signal opposite to the second-level signal to the control system 21. The control system 21 records an electrostatic interference event of the meter according to the edge change of the level signal. The control system 21 can also upload the electrostatic interference event to the terminal, so that the operator can remotely view the electrostatic interference situation of the meter by using the terminal and perform fault troubleshooting in time.

[0064] For the meter provided in this embodiment, the magnitude of the voltage signal reflects the quantity of the static charges on the inner surface of the housing of the meter body. The signal trigger can switch its on-off state based on the magnitude of the voltage signal. When the static charges exceed a certain quantity, the voltage signal increases at this time, causing the signal trigger to switch the switching state and output the first-level signal, indicating that the meter body is affected by electrostatic interference. Thus, the detection of electrostatic interference on the inner surface of the housing of the meter body is realized, and the electrostatic interference detection circuit only includes the charge processing circuit and the signal trigger. The meter structure is simple and easy to manufacture.

[0065] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An electrostatic interference detection circuit, characterized in that, It is applied to an electric meter. The electrostatic interference detection circuit includes: a charge processing circuit and a signal trigger. Among them, The charge processing circuit, its input end collects the static charge of the detection end of the electric meter, its output end is connected to the input end of the signal trigger, and it is used to convert the static charge into a voltage signal; The signal trigger, its power supply end is connected to the first power supply; When the charge processing circuit collects static charge and the voltage signal is greater than the conduction voltage drop of the signal trigger, the signal trigger switches its switch state and outputs a first level signal, and the first level signal indicates that the electric meter is affected by electrostatic interference.

2. The electrostatic interference detection circuit according to claim 1, wherein The charge processing circuit includes: a signal collector and a signal amplifier. Among them, The signal collector, its input end collects static charge, its output end is connected to the input end of the signal amplifier, its first end is connected to the first end of the signal amplifier and then grounded, and it is used to convert the static charge into an initial voltage signal; The signal amplifier, its first power supply end is connected to the first power supply, its second power supply end is connected to the second power supply, its output end is connected to the input end of the signal trigger, and it is used to amplify the initial voltage signal and then output the voltage signal; The first power supply and the second power supply are equal in magnitude and opposite in direction.

3. The electrostatic interference detection circuit according to claim 2, characterized in that The signal collector includes: a storage circuit and a first clamping circuit. Among them, The first end after the storage circuit and the first clamping circuit are connected in parallel is connected to the first end of the signal amplifier, and the second end after the storage circuit and the first clamping circuit are connected in parallel is connected to the input end of the signal amplifier; The first clamping circuit is used to suppress the voltage at the input end of the signal amplifier; The storage circuit is used to store the static charge and then generate a voltage signal.

4. The electrostatic interference detection circuit according to claim 2, wherein The signal amplifier includes: a first voltage dividing circuit and an amplifying circuit. Among them, The amplifying circuit, its input end is connected to the output end of the signal collector, its output end is connected to the first end of the first voltage dividing circuit and the input end of the signal trigger and then outputs the voltage signal, its first end is connected to the second end of the first voltage dividing circuit, its first power supply end is connected to the first power supply, its second power supply end is connected to the second power supply, and it is used to amplify the initial voltage signal based on the first power supply and the second power supply and then output the voltage signal; The first voltage dividing circuit, its third end is connected to the output end of the signal collector, and by adjusting the ratio of the resistance values inside the first voltage dividing circuit, the intensity of the voltage signal is adjusted.

5. The electrostatic interference detection circuit according to claim 4, wherein, The signal amplifier further includes: A power conversion circuit, its input end is connected to the first power supply and the first power supply end of the amplifying circuit, its output end is connected to the second power supply end of the amplifying circuit, and it is used to convert the first power supply into the second power supply.

6. The electrostatic interference detection circuit according to claim 1, characterized in that, The signal trigger includes: a first trigger unit and a second trigger unit. Among them, The first trigger unit, its control end is connected to the output end of the charge processing circuit and the first end of the second trigger unit, its first end is connected to the control end of the second trigger unit, and its second end is connected to the second end of the second trigger unit; When the voltage signal is positive and the voltage signal is greater than the conduction voltage drop of the first trigger unit, after the first trigger unit conducts and the second trigger unit turns off, the second terminal of the first trigger unit outputs the first level signal; When the voltage signal is negative and the absolute value of the voltage signal is greater than the conduction voltage drop of the second trigger unit, after the second trigger unit conducts and the first trigger unit turns off, the second terminal of the second trigger unit outputs the first level signal.

7. The electrostatic interference detection circuit according to claim 6, wherein The first trigger unit includes: a first switch, a first resistor, a second resistor, a third resistor, a fourth resistor, and a first capacitor, where The first resistor, its first terminal is connected to the output terminal of the charge processing circuit, and its second terminal is connected to the control terminal of the first switch and the first terminal of the second resistor; The second resistor, its second terminal is connected to the first terminal of the first switch, the control terminal of the second trigger unit, and the first terminal of the first capacitor and then grounded; The first switch, its second terminal is connected to the first terminal of the third resistor and the first terminal of the fourth resistor; The third resistor, its second terminal is connected to the first power supply; The fourth resistor, its second terminal is connected to the second terminal of the first capacitor and the second terminal of the second trigger unit; When the voltage signal is positive and the voltage signal is greater than the conduction voltage drop of the first switch, after the first switch conducts and the second trigger unit turns off, the second terminal of the first switch outputs the first level signal through the fourth resistor.

8. The electrostatic interference detection circuit according to claim 7, wherein, The second trigger unit includes: a first switch circuit and a second switch circuit, where The first switch circuit, its first terminal is connected to the output terminal of the charge processing circuit, its control terminal is connected to the first terminal of the first switch, its second terminal is connected to the first power supply, and its third terminal is connected to the control terminal of the second switch circuit; The second switch circuit, its first terminal is connected to the first power supply, its second terminal is connected to the second terminal of the first trigger unit, and its third terminal is grounded; When the voltage signal is negative and the absolute value of the voltage signal is greater than the conduction voltage drop of the first switch circuit, after the first switch circuit conducts and the second switch circuit conducts, the second terminal of the second switch circuit outputs the first level signal.

9. The electrostatic interference detection circuit according to claim 6, characterized in that The signal trigger further includes: A second clamping circuit, its first terminal and second terminal are respectively connected to the second terminal of the first trigger unit and the third terminal of the second trigger unit, and it is used to suppress the voltage of the outputs of the second terminals of the first trigger unit and the second trigger unit.

10. An electric meter, characterized in that, It includes an electric meter body and the electrostatic interference detection circuit according to any one of claims 1 to 9, where the input terminal of the charge processing circuit collects the static charge on the inner surface of the housing of the electric meter body; The input terminal of the control system in the electric meter body is connected to the output terminal of the signal trigger; When the charge processing circuit collects static charge and the voltage signal corresponding to the static charge is greater than the conduction voltage drop of the signal trigger, after the signal trigger switches the switch state and outputs the first level signal, the control system records an electrostatic interference event of the electric meter body once.

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