Switching-on and switching-off relay driving circuit for electric energy meter and acquisition terminal

Abstract

The utility model relates to a switching-on and switching-off relay driving circuit for an electric energy meter and an acquisition terminal. The switching-on and switching-off relay driving circuit comprises a driving unit, an electric switching-on relay, a TVS tube and an RC absorption circuit, the input end of the driving unit is connected with the power supply end and the processing unit; the first input end and the second input end of the electric pull-on relay are connected with the first output end and the second output end of the driving unit respectively, and the output end of the electric pull-on relay is used for being connected with a load circuit; one end of the TVS tube is connected in parallel between the first input end of the electric switching-on relay and the first output end of the driving unit, and the other end of the TVS tube is connected in parallel between the second input end of the electric switching-on relay and the second output end of the driving unit; one end of the RC absorption circuit is connected in parallel between the first input end of the electric pull-on relay and the first output end of the driving unit, and the other end of the RC absorption circuit is connected in parallel between the second input end of the electric pull-on relay and the second output end of the driving unit.

Description

TECHNICAL FIELD

[0001] The utility model relates to drive circuit technical field especially relates to a pull -on and pull -off brake relay drive circuit for electric energy meter and collection terminal. BACKGROUND

[0002] With the development of intelligent power system, electric energy meter and collection terminal bear the heavy responsibility of accurate measurement and flexible control of electricity, and pull -on and pull -off brake relay as the key component brings many influences to the circuit. As inductive load, the relay will cause voltage fluctuation in the instant of attraction and disconnection, and easily damage other elements. The inrush current in the instant of power -on will increase the burden of power supply. At the same time, the electromagnetic interference produced by the relay action affects other sensitive elements and modules through radiation and conduction, resulting in data transmission error, inaccurate measurement and other problems. It seriously affects the control accuracy of electric energy meter and collection terminal and the stability of power system operation. SUMMARY

[0003] Therefore, the utility model provides a pull -on and pull -off brake relay drive circuit for electric energy meter and collection terminal for solving the problem of damage to the driving unit or other elements caused by the energy impact generated by the pull -on and pull -off brake relay in the prior art.

[0004] In order to achieve one or part or all of the above purposes or other purposes, the utility model provides a pull -on and pull -off brake relay drive circuit for electric energy meter and collection terminal, which comprises: a driving unit, an electric pull -on relay, a TVS tube, an RC absorbing circuit.

[0005] The input end of the driving unit is used for connecting the power supply end and the processing unit.

[0006] The first input end and the second input end of the electric pull -on relay are connected with the first output end and the second output end of the driving unit respectively, and the output end of the electric pull -on relay is used for connecting the load circuit.

[0007] One end of the TVS tube is connected in parallel between the first input end of the electric pull -on relay and the first output end of the driving unit, and the other end of the TVS tube is connected in parallel between the second input end of the electric pull -on relay and the second output end of the driving unit.

[0008] One end of the RC absorbing circuit is connected in parallel between the first input end of the electric pull -on relay and the first output end of the driving unit, and the other end of the RC absorbing circuit is connected in parallel between the second input end of the electric pull -on relay and the second output end of the driving unit.

[0009] Further, the pull-in and pull-out relay driving circuit for the electric energy meter and the collection terminal further comprises: a first voltage stabilizing diode and a second voltage stabilizing diode.

[0010] One end of the first voltage stabilizing diode is connected in parallel between the first input end of the pull-in relay and the first output end of the driving unit, and the other end of the first voltage stabilizing diode is used for connecting a ground end.

[0011] One end of the second voltage stabilizing diode is connected in parallel between the second input end of the pull-in relay and the second output end of the driving unit, and the other end of the second voltage stabilizing diode is used for connecting a ground end.

[0012] Further, the driving unit comprises: a first triode, a second triode, a third triode and a fourth triode.

[0013] The emitter of the first triode is used for connecting the power supply end.

[0014] The emitter of the second triode is used for connecting the power supply end.

[0015] The collector of the third triode is connected to the collector of the first triode and the base of the second triode, the emitter of the third triode is used for connecting a ground end, and the base of the third triode is used for communicatively connecting the processing unit.

[0016] The collector of the fourth triode is connected to the collector of the second triode and the base of the first triode, the emitter of the fourth triode is used for connecting a ground end, and the base of the fourth triode is used for communicatively connecting the processing unit.

[0017] The first input end of the pull-in relay is connected in parallel between the base of the first triode and the collector of the fourth triode, and forms a first parallel point; the second input end of the pull-in relay is connected in parallel between the base of the second triode and the collector of the third triode, and forms a second parallel point; and the two ends of the RC absorption circuit are connected to the first parallel point and the second parallel point, respectively.

[0018] Further, the RC absorption circuit comprises: an absorption capacitor and an absorption resistor.

[0019] One end of the absorption capacitor is connected to the second parallel point.

[0020] One end of the absorption resistor is connected in series to the other end of the absorption capacitor, and the other end of the absorption resistor is connected to the first parallel point.

[0021] Further, the pull-in and pull-out relay driving circuit for the electric energy meter and the collection terminal further comprises: a power supply protection resistor and an electrolytic capacitor.

[0022] One end of the power supply protection resistor is used for connecting the power supply end, and the other end is connected to the input end of the driving unit;

[0023] One end of the electrolytic capacitor is connected in parallel between the power supply protection resistor and the input end of the driving unit.

[0024] Further, the pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal further comprises a first protection resistor;

[0025] The first protection resistor is connected in series between the base of the first triode and the first parallel point.

[0026] Further, the pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal further comprises a second protection resistor;

[0027] The second protection resistor is connected in series between the base of the second triode and the second parallel point.

[0028] Further, the pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal further comprises a third protection resistor;

[0029] The third protection resistor is connected in series between the base of the third triode and the processing unit.

[0030] Further, the pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal further comprises a fourth protection resistor;

[0031] The fourth protection resistor is connected in series between the base of the fourth triode and the processing unit.

[0032] Further, the pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal further comprises a fifth protection resistor;

[0033] The fifth protection resistor is connected in series between the output end of the electric pull-in relay and the input end of the load circuit.

[0034] The embodiment of the utility model is implemented, will have the following beneficial effects:

[0035] The pull-in and pull-out relay driving circuit facing the electric energy meter and the collection terminal provided by the utility model absorbs the impact energy greater than or equal to the specified voltage value through the TVS tube; then the RC absorption circuit not only absorbs the impact energy less than the specified voltage value, but also absorbs the impact energy greater than or equal to the specified voltage value that the TVS tube fails to absorb; so that the maximum energy range that can be absorbed on the circuit is wider; and the high-energy impact generated by the electric pull-in relay during operation is avoided to cause damage to the driving unit, the power supply end and other elements. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Among them:

[0038] Figure 1 It is a circuit connection schematic diagram of the pull-in and pull-out relay driving circuit facing the electric energy meter and the acquisition terminal in an embodiment of the present application.

[0039] Figure 2 It is a partial circuit connection schematic diagram of the pull-in and pull-out relay driving circuit facing the electric energy meter and the acquisition terminal in an embodiment of the present application.

[0040] Figure 3 It is another partial circuit connection schematic diagram of the pull-in and pull-out relay driving circuit facing the electric energy meter and the acquisition terminal in an embodiment of the present application.

[0041] Reference signs:

[0042] 10, driving unit; 11, first triode; 12, second triode; 13, third triode; 14, fourth triode; 15, first parallel point; 16, second parallel point; 20, electric pull-in relay; 30, TVS tube; 40, RC absorption circuit; 41, absorption capacitor; 42, absorption resistor; 50, power supply end; 60, processing unit; 70, load circuit; 80, first voltage stabilizing diode; 90, second voltage stabilizing diode; 100, first protection resistor; 110, second protection resistor; 120, third protection resistor; 130, fourth protection resistor; 140, fifth protection resistor; 150, power supply protection resistor; 160, electrolytic capacitor. DETAILED DESCRIPTION

[0043] Unless otherwise defined, 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 in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application; the present application is well suited to carry out the objects and to attain the ends specified herein above with respect to the technical solutions of the present application; the terms "comprise", "comprising", "including", "including", "have" and "having" and any variations thereof in the specification and claims herein are intended to cover both the case where the stated feature is included and the case where the stated feature is not included; the terms "first", "second" and the like in the specification and claims herein are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order; the cold water mentioned in the specification and claims herein includes normal temperature water.

[0044] Reference herein to "embodiment" means that a particular feature, structure, 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 they necessarily mutually exclusive or alternative embodiments. It is explicitly and implicitly understood that the embodiments described herein can be combined with other embodiments.

[0045] In order to make the technical personnel in the technical field better understand the application scheme, the technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings.

[0046] With reference to Figures 1 to 3 The first embodiment of the application provides a pull-in and pull-out relay driving circuit for an electric energy meter and a collection terminal, which comprises a driving unit 10, an electric pull-in and pull-out relay 20, a TVS tube 30 and an RC absorption circuit 40.

[0047] The input end of the driving unit 10 is used for connecting a power supply end 50 and a processing unit 60.

[0048] The first input end and the second input end of the electric pull-in and pull-out relay 20 are respectively connected to the first output end and the second output end of the driving unit 10, and the output end of the electric pull-in and pull-out relay 20 is used for connecting a load circuit 70.

[0049] One end of the TVS tube 30 is connected in parallel between the first input end of the electric pull-in and pull-out relay 20 and the first output end of the driving unit 10, and the other end of the TVS tube 30 is connected in parallel between the second input end of the electric pull-in and pull-out relay 20 and the second output end of the driving unit 10.

[0050] One end of the RC absorption circuit 40 is connected in parallel between the first input end of the electric closing relay 20 and the first output end of the driving unit 10, and the other end of the RC absorption circuit 40 is connected in parallel between the second input end of the electric closing relay 20 and the second output end of the driving unit 10.

[0051] In the embodiment, when the electric closing relay 20 is closed, a back electromotive force is generated in the coil inside the electric closing relay 20 to form a high-energy impact, and the impact energy greater than or equal to a specified voltage value is absorbed by the TVS tube 30.

[0052] Through the RC absorption circuit 40, not only the impact energy pulse of the large voltage that is not absorbed by the TVS tube 30 is absorbed, but also the impact energy pulse of a smaller voltage is absorbed, and the maximum energy range that can be absorbed on the circuit is further widened, and the electromagnetic interference is further reduced.

[0053] In summary, the electric closing relay driving circuit for the electric energy meter and the collection terminal further improves the voltage protection range on the circuit, reduces the influence of the transient impact generated by the operation of the electric closing relay 20 on the driving unit 10 and the power supply end 50, and reduces the electromagnetic interference; and damage to the driving unit 10, the power supply end 50 and other elements caused by the impact energy is avoided.

[0054] Specifically, the TVS tube 30 is a transient voltage suppression diode.

[0055] Referring to Figure 1 and Figure 3 , the electric closing relay driving circuit for the electric energy meter and the collection terminal further comprises: a first voltage stabilizing diode 80 and a second voltage stabilizing diode 90.

[0056] One end of the first voltage stabilizing diode 80 is connected in parallel between the first input end of the electric closing relay 20 and the first output end of the driving unit 10, and the other end of the first voltage stabilizing diode 80 is used to connect a ground end.

[0057] One end of the second voltage stabilizing diode 90 is connected in parallel between the second input end of the electric closing relay 20 and the second output end of the driving unit 10, and the other end of the second voltage stabilizing diode 90 is used to connect a ground end.

[0058] In the embodiment, the first voltage stabilizing diode 80 and the second voltage stabilizing diode 90 cooperate with the TVS tube 30 to absorb the impact energy, so that the maximum energy range that can be absorbed on the circuit is widened, and damage to the driving unit 10, the power supply end 50 and other elements caused by the energy impact generated by the operation of the electric closing relay 20 is further ensured.

[0059] Referring to Figures 1 to 2, the driving unit 10 comprises: a first triode 11, a second triode 12, a third triode 13, a fourth triode 14;

[0060] The emitter of the first triode 11 is used for connecting the power supply end 50;

[0061] The emitter of the second triode 12 is used for connecting the power supply end 50;

[0062] The collector of the third triode 13 is connected with the collector of the first triode 11 and the base of the second triode 12 respectively, the emitter of the third triode 13 is used for connecting the ground end, and the base of the third triode 13 is used for being connected with the processing unit 60 in communication;

[0063] The collector of the fourth triode 14 is connected with the collector of the second triode 12 and the base of the first triode 11 respectively, the emitter of the fourth triode 14 is used for connecting the ground end, and the base of the fourth triode 14 is used for being connected with the processing unit 60 in communication;

[0064] The first input end of the electrically latching relay 20 is connected in parallel between the base of the first triode 11 and the collector of the fourth triode 14, and forms a first parallel point 15; the second input end of the electrically latching relay 20 is connected in parallel between the base of the second triode 12 and the collector of the third triode 13, and forms a second parallel point 16; the two ends of the RC absorption circuit 40 are connected to the first parallel point 15 and the second parallel point 16 respectively.

[0065] In the embodiment, when the third triode 13 receives the on signal sent by the processing unit 60, the third triode 13 pulls down the base voltage of the second triode 12, so that the second triode 12 is cut off and turned on, and then the second triode 12 sends a low level signal to the second input end of the electrically latching relay 20; when the third triode 13 receives the off signal, the third triode 13 does not pull down the base voltage of the second triode 12, at this time the second triode 12 is turned on, and then the second triode 12 sends a high level signal to the second input end of the electrically latching relay 20;

[0066] Similarly, when the fourth triode 14 receives the on signal sent by the processing unit 60, the fourth triode 14 pulls down the base voltage of the first triode 11, so that the first triode 11 is cut off and turned on, and then the first triode 11 sends a low level signal to the first input end of the electrically latching relay 20; when the fourth triode 14 receives the off signal, the fourth triode 14 does not pull down the base voltage of the first triode 11, at this time the first triode 11 is turned on, and then the first triode 11 sends a high level signal to the first input end of the electrically latching relay 20.

[0067] In summary, the working state of the electric pull-in relay 20 is regulated by the first transistor 11, the second transistor 12, the third transistor 13 and the fourth transistor 14.

[0068] Specifically, the first transistor 11 and the second transistor 12 are both PNP type transistors, and the third transistor 13 and the fourth transistor 14 are both NPN type transistors.

[0069] The TVS tube 30, in combination with the first voltage stabilizing diode 80 and the second voltage stabilizing diode 90, shares the energy impact of the large voltage generated when the electric pull-in relay 20 is working, and the RC absorbing circuit 40 absorbs the energy impact of the large voltage and the small voltage generated when the electric pull-in relay 20 is working, so as to avoid damaging the first transistor 11, the second transistor 12, the third transistor 13 and the fourth transistor 14, thereby ensuring the normal working of the electric pull-in relay 20.

[0070] With reference to Figures 1 to 2 , the RC absorbing circuit 40 comprises an absorbing capacitor 41 and an absorbing resistor 42.

[0071] One end of the absorbing capacitor 41 is connected to the second parallel point 16.

[0072] One end of the absorbing resistor 42 is connected in series to the other end of the absorbing capacitor 41, and the other end of the absorbing resistor 42 is connected to the first parallel point 15.

[0073] In this embodiment, the absorbing capacitor 41 and the absorbing resistor 42 complete the connection of an RC absorbing circuit 40, which is used to reduce voltage spikes and electromagnetic interference in the circuit.

[0074] With reference to Figures 1 to 2 , the pull-in relay driving circuit for the electric energy meter and the collection terminal further comprises a power supply protection resistor 150 and an electrolytic capacitor 160.

[0075] One end of the power supply protection resistor 150 is used to connect the power supply end 50, and the other end is connected to the input end of the driving unit 10.

[0076] One end of the electrolytic capacitor 160 is connected in parallel between the power supply protection resistor 150 and the input end of the driving unit 10.

[0077] In the embodiment, the power supply protection resistor 150 is used to avoid the damage of the driving unit 10 caused by the large current and large voltage of the power supply end 50, and further improve the reliability of the overall circuit. The electrolytic capacitor 160 is used to absorb the residual power of the power supply end 50, and when the power supply of the power supply end 50 is stopped, the electrolytic capacitor 160 is discharged to ensure the quick response of the driving unit 10 to control the electrically-operated relay 20. Not only the energy consumption of the circuit is reduced, but also the response speed of the circuit is improved.

[0078] With reference to Figures 1 to 2 , the driving circuit of the electric energy meter and the collection terminal further comprises a first protection resistor 100.

[0079] The first protection resistor 100 is connected in series between the base of the first transistor 11 and the first parallel point 15.

[0080] In the embodiment, the first protection resistor 100 is used to avoid the damage of the first transistor 11, the fourth transistor 14, or the electrically-operated relay 20 caused by the large current and large voltage on the circuit, and further improve the safety and stability of the circuit. In combination with the first transistor 11 and the fourth transistor 14, the first protection resistor 100 plays a role of current limiting and voltage dividing, thereby controlling the switching state of the electrically-operated relay 20.

[0081] With reference to Figures 1 to 2 , the driving circuit of the electric energy meter and the collection terminal further comprises a second protection resistor 110.

[0082] The second protection resistor 110 is connected in series between the base of the second transistor 12 and the second parallel point 16.

[0083] In the embodiment, the second protection resistor 110 is used to avoid the damage of the second transistor 12, the third transistor 13, or the electrically-operated relay 20 caused by the large current and large voltage on the circuit, and further improve the safety and stability of the circuit. In combination with the second transistor 12 and the third transistor 13, the second protection resistor 110 plays a role of current limiting and voltage dividing, thereby controlling the switching state of the electrically-operated relay 20.

[0084] With reference to Figures 1 to 2 , the driving circuit of the electric energy meter and the collection terminal further comprises a third protection resistor 120.

[0085] The third protection resistor 120 is connected in series between the base of the third transistor 13 and the processing unit 60.

[0086] In the embodiment, the third protective resistor 120 is added to limit current, divide voltage and prevent signal interference, so that the control signal sent by the processing unit 60 to the third triode 13 is not interfered by other signals, thereby ensuring the accuracy of the control signal sent to the third triode 13 and improving the reliability of the overall circuit.

[0087] With reference to Figures 1 to 2 , the pull-in and pull-out relay driving circuit for electric energy meter and collection terminal further comprises a fourth protective resistor 130.

[0088] The fourth protective resistor 130 is connected in series between the base of the fourth triode 14 and the processing unit 60.

[0089] In the embodiment, the fourth protective resistor 130 is added to limit current, divide voltage and prevent signal interference, so that the control signal sent by the processing unit 60 to the fourth triode 14 is not interfered by other signals, thereby ensuring the accuracy of the control signal sent to the fourth triode 14 and improving the reliability of the overall circuit.

[0090] With reference to Figure 1 and Figure 3 , the pull-in and pull-out relay driving circuit for electric energy meter and collection terminal further comprises a fifth protective resistor 140.

[0091] The fifth protective resistor 140 is connected in series between the output of the electric pull-in relay 20 and the input of the load circuit 70.

[0092] In the embodiment, the fifth protective resistor 140 plays a role of overload protection. When the load circuit 70 is overloaded, the fifth protective resistor 140 can limit the current passing through the electric pull-in relay 20 to prevent the electric pull-in relay 20 from being damaged due to overload. The fifth protective resistor 140 also provides circuit isolation to reduce the influence of the load circuit 70 on the electric pull-in relay 20 and improve the anti-interference ability of the circuit. In addition, the series connection of the fifth protective resistor 140 helps to stabilize the input voltage of the load circuit 70 and ensure the normal operation of the load device.

[0093] In some embodiments, the pull-in and pull-out relay driving circuit for electric energy meter and collection terminal further comprises a sixth protective resistor.

[0094] The sixth protective resistor is connected in parallel between the output of the electric pull-in relay 20 and the input of the load circuit 70.

[0095] Obviously, the above-described embodiments are only a part of the embodiments of the present application, rather than all the embodiments, and the preferred embodiments of the present application are given in the drawings, but do not limit the patent scope of the present application. The present application can be realized in many different forms, and conversely, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing specific embodiments, or equivalently replace some of the technical features. Any equivalent structure made by using the content of the present application specification and drawings, directly or indirectly used in other related technical fields, is also within the patent protection scope of the present application.

Claims

1. A circuit for driving a circuit breaker relay for electricity meters and data acquisition terminals, characterized in that, include: A drive unit, the input terminal of which is used to connect to a power supply terminal and a processing unit; An electrically operated relay is provided, wherein the first input terminal and the second input terminal of the electrically operated relay are respectively connected to the first output terminal and the second output terminal of the drive unit, and the output terminal of the electrically operated relay is used to connect to the load circuit. TVS diode, one end of which is connected in parallel between the first input terminal of the electrically connected relay and the first output terminal of the drive unit, and the other end of which is connected in parallel between the second input terminal of the electrically connected relay and the second output terminal of the drive unit; An RC snubber circuit is provided, with one end of the RC snubber circuit connected in parallel between the first input terminal of the electrically operated relay and the first output terminal of the drive unit, and the other end of the RC snubber circuit connected in parallel between the second input terminal of the electrically operated relay and the second output terminal of the drive unit.

2. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 1, characterized in that, The circuit for driving the opening and closing relays for the energy meter and the data acquisition terminal also includes: A first Zener diode, one end of which is connected in parallel between the first input terminal of the electrically operated relay and the first output terminal of the drive unit, and the other end of which is used to connect to the ground terminal; The second Zener diode has one end connected in parallel between the second input terminal of the electrically operated relay and the second output terminal of the drive unit, and the other end of the second Zener diode is used to connect to the ground terminal.

3. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 2, characterized in that, The driving unit includes: The first transistor, wherein the emitter of the first transistor is used to connect to the power supply terminal; The second transistor, wherein the emitter of the second transistor is used to connect to the power supply terminal; The third transistor has its collector connected to the collector of the first transistor and the base of the second transistor, its emitter connected to the ground terminal, and its base connected to the processing unit for communication. The fourth transistor has its collector connected to the collector of the second transistor and the base of the first transistor, its emitter connected to the ground terminal, and its base connected to the processing unit for communication. The first input terminal of the electrically operated relay is connected in parallel between the base of the first transistor and the collector of the fourth transistor, forming a first parallel connection point; the second input terminal of the electrically operated relay is connected in parallel between the base of the second transistor and the collector of the third transistor, forming a second parallel connection point; the two ends of the RC snubber circuit are respectively connected to the first parallel connection point and the second parallel connection point.

4. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 3, characterized in that, The RC snubber circuit includes: An absorption capacitor, one end of which is connected to the second parallel point; An absorption resistor is provided, one end of which is connected in series to the other end of the absorption capacitor, and the other end of which is connected to the first parallel point.

5. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 1, characterized in that, The circuit for driving the opening and closing relays for the energy meter and the data acquisition terminal also includes: A power supply protection resistor, one end of which is connected to the power supply terminal, and the other end of which is connected to the input terminal of the drive unit; An electrolytic capacitor, one end of which is connected in parallel between the power supply protection resistor and the input terminal of the drive unit.

6. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 4, characterized in that, The circuit for opening and closing relays for electricity meters and data acquisition terminals also includes: a first protective resistor; The first protective resistor is connected in series between the base of the first transistor and the first parallel connection point.

7. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 4, characterized in that, The circuit for opening and closing relays for electricity meters and data acquisition terminals also includes: a second protective resistor; The second protection resistor is connected in series between the base of the second transistor and the second parallel connection point.

8. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 3, characterized in that, The circuit for the opening and closing relays for electricity meters and data acquisition terminals also includes: a third protection resistor; The third protection resistor is connected in series between the base of the third transistor and the processing unit.

9. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 3, characterized in that, The circuit for opening and closing relays for electricity meters and data acquisition terminals also includes: a fourth protection resistor; The fourth protection resistor is connected in series between the base of the fourth transistor and the processing unit.

10. The circuit for opening and closing relays for electricity meters and data acquisition terminals according to claim 2, characterized in that, The circuit for opening and closing relays for electricity meters and data acquisition terminals also includes: a fifth protective resistor; The fifth protective resistor is connected in series between the output terminal of the electrically operated relay and the input terminal of the load circuit.

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