CN219843456U - Power supply switching circuit and intelligent electric energy meter - Google Patents
Power supply switching circuit and intelligent electric energy meter Download PDFInfo
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- CN219843456U CN219843456U CN202320995876.9U CN202320995876U CN219843456U CN 219843456 U CN219843456 U CN 219843456U CN 202320995876 U CN202320995876 U CN 202320995876U CN 219843456 U CN219843456 U CN 219843456U
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Abstract
The utility model relates to a power supply switching circuit and an intelligent electric energy meter, comprising: the power supply circuit comprises a first power supply circuit, a second power supply circuit and a switch module, wherein the output end of the first power supply circuit is electrically connected with the first end of the switch module, the output end of the second power supply circuit is electrically connected with the second end of the switch module, and the third end of the switch module is electrically connected with a load; the first power supply circuit comprises a first power supply, a voltage stabilizing module and a first capacitor, wherein the first end of the voltage stabilizing module is electrically connected with the first end of the first capacitor, the first end of the first capacitor is electrically connected between the first end of the voltage stabilizing module and the first end of the switch module, the second end of the voltage stabilizing module and the second end of the first capacitor are grounded, and the third end of the voltage stabilizing module is electrically connected with the first power supply; the first power supply circuit and the load are conducted through the switch module, or the second power supply circuit and the load are conducted, so that the first power supply circuit or the second power supply circuit provides electric energy for the load, and automatic switching and seamless connection between the two power supplies are realized.
Description
Technical Field
The embodiment of the utility model relates to the technical field of intelligent electric energy meters, in particular to a power supply switching circuit and an intelligent electric energy meter.
Background
With the continuous development of smart grid technology, smart electric energy meters are increasingly widely used. The intelligent electric energy meter generally adopts two power supplies, one is commercial power and the other is a battery.
However, in the transportation and storage processes of the intelligent electric energy meter, the situation that the intelligent electric energy meter is not connected with the mains supply exists, namely the intelligent electric energy meter is not externally connected with 220V alternating current, and in the actual work of the intelligent electric energy meter, the situation that the mains supply is powered down is likely to happen, so that the intelligent electric energy meter is transported, stored and actually works, and a battery is required to be used as a power supply to ensure that a clock chip and an anti-electricity-theft switch of the intelligent electric energy meter are always in a working state. When the intelligent electric energy meter is switched on again to the mains supply, the power supply is required to be switched to the mains supply, long-time battery loss is avoided, and the service life of the intelligent electric energy meter is shortened.
Therefore, how to automatically switch between two power supplies of the intelligent electric energy meter becomes a problem to be solved.
Disclosure of Invention
In view of the above problems, embodiments of the present utility model provide a power supply switching circuit and an intelligent electric energy meter, which can automatically switch between two power supply sources, and can seamlessly connect the two power supply sources in the switching process.
In a first aspect of the embodiment of the present utility model, a power switching circuit is provided, where the power switching circuit includes a first power supply circuit, a second power supply circuit, and a switch module, an output end of the first power supply circuit is electrically connected to a first end of the switch module, an output end of the second power supply circuit is electrically connected to a second end of the switch module, and a third end of the switch module is electrically connected to a load;
the first power supply circuit comprises a first power supply, a voltage stabilizing module and a first capacitor, wherein the first end of the voltage stabilizing module is electrically connected with the first end of the switch module, the first end of the first capacitor is electrically connected between the first end of the voltage stabilizing module and the first end of the switch module, the second end of the voltage stabilizing module and the second end of the first capacitor are grounded, and the third end of the voltage stabilizing module is electrically connected with the first power supply;
and the switch module is used for conducting the first power supply circuit and the load or conducting the second power supply circuit and the load.
In an alternative manner, the load comprises a micro control unit and a plurality of load branches, and the third end of the switch module is electrically connected with the first end of the micro control unit and the plurality of load branches respectively;
and the micro control unit is used for controlling part of all load branches to be not operated when the voltage of the third end of the voltage stabilizing module is smaller than a threshold value, wherein the threshold value is larger than the output voltage of the first power supply circuit.
In an optional manner, the power supply detection circuit further comprises a voltage detection circuit, a first end of the voltage detection circuit and a third end of the voltage stabilizing module are electrically connected with the first power supply through the same connection point, and a second end of the voltage detection circuit is electrically connected with a second end of the micro control unit;
and the voltage detection circuit is used for detecting the voltage of the third end of the voltage stabilizing module.
In an alternative mode, the voltage detection circuit comprises a first resistor and a second resistor, the first end of the first resistor is electrically connected with the connecting point, the second end of the first resistor is electrically connected with the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the micro control unit is electrically connected between the second end of the first resistor and the first end of the second resistor.
In an alternative manner, the voltage detection circuit further includes a second capacitor, a first end of the second capacitor is electrically connected to the connection point, and a second end of the second capacitor is grounded.
In an alternative mode, the voltage stabilizing module includes a linear voltage stabilizer and a first diode, an output end of the linear voltage stabilizer is electrically connected with a first end of the switch module, a ground end of the linear voltage stabilizer is electrically connected with a first end of the first diode, an input end of the linear voltage stabilizer is electrically connected with a first power supply, and a second end of the first diode is grounded.
In an alternative manner, the second power supply circuit includes a second power supply, a first end of the second power supply is electrically connected to the second end of the switch module, and a second end of the second power supply is grounded.
In an alternative manner, the second power supply circuit further comprises a third resistor and a fourth resistor, the first end of the third resistor is electrically connected with the first end of the second power supply, the second end of the third resistor is electrically connected with the first end of the fourth resistor, the second end of the fourth resistor is grounded, and the third end of the micro control unit is electrically connected between the second end of the third resistor and the first end of the fourth resistor;
and the micro control unit is also used for detecting whether the output voltage of the second power supply is constant.
In an alternative manner, the switch module includes a second diode and a third diode, a first end of the second diode is electrically connected to the output end of the first power supply circuit, a first end of the third diode is electrically connected to the output end of the second power supply circuit, and a second end of the second diode and a second end of the third diode are both electrically connected to the load.
In a second aspect of the embodiments of the present utility model, an intelligent electric energy meter is provided, which includes a load and the power switching circuit in the foregoing embodiments.
The embodiment of the utility model provides a power supply switching circuit and an intelligent electric energy meter, wherein the power supply switching circuit comprises a first power supply circuit, a second power supply circuit and a switch module, the output end of the first power supply circuit is electrically connected with the first end of the switch module, the output end of the second power supply circuit is electrically connected with the second end of the switch module, and the third end of the switch module is electrically connected with a load; the first power supply circuit comprises a first power supply, a voltage stabilizing module and a first capacitor, wherein the first end of the voltage stabilizing module is electrically connected with the first end of the first capacitor, the first end of the first capacitor is electrically connected between the first end of the voltage stabilizing module and the first end of the switch module, the second end of the voltage stabilizing module and the second end of the first capacitor are grounded, and the third end of the voltage stabilizing module is electrically connected with the first power supply; the first power supply circuit and the load are conducted through the switch module, or the second power supply circuit and the load are conducted, so that the first power supply circuit or the second power supply circuit provides electric energy for the load, and the intelligent electric energy meter can automatically switch between two power supplies. And in the process that the switch module switches the power supply of the load from the first power supply circuit to the second power supply circuit, as the first capacitor can store electric energy, the first power supply circuit continues to supply energy to the load until the second power supply circuit supplies energy to the load, so that in the switching process, the two power supplies can be connected in a seamless manner.
The foregoing description is only an overview of the technical solutions of the embodiments of the present utility model, and may be implemented according to the content of the specification, so that the technical means of the embodiments of the present utility model can be more clearly understood, and the following specific embodiments of the present utility model are given for clarity and understanding.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a power switching circuit according to an embodiment of the present utility model;
fig. 2 is a schematic diagram of a voltage when a mains supply is powered down according to an embodiment of the present utility model;
fig. 3 is a schematic diagram of another power switching circuit according to an embodiment of the present utility model;
fig. 4 is a schematic diagram of another voltage when the mains supply is powered down according to an embodiment of the present utility model.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
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 utility model belongs; the terminology used in the description of the applications herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model; the terms "comprising" and "having" and any variations thereof in the description and claims of the utility model and in the description of the drawings are intended to cover a non-exclusive inclusion.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of the phrase "an embodiment" 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. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: there are three cases, a, B, a and B simultaneously. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.
Furthermore, the terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not for describing a particular sequential order, and may be used to improve one or more of these features either explicitly or implicitly.
In the description of the present utility model, unless otherwise indicated, the meaning of "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two).
In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, e.g., as a "connected" or "coupled" of a mechanical structure may refer to a physical connection, e.g., as a fixed connection, e.g., via a fastener, such as a screw, bolt, or other fastener; the physical connection may also be a detachable connection, such as a snap-fit or snap-fit connection; the physical connection may also be an integral connection, such as a welded, glued or integrally formed connection. "connected" or "connected" of circuit structures may refer to physical connection, electrical connection or signal connection, for example, direct connection, i.e. physical connection, or indirect connection through at least one element in the middle, so long as circuit communication is achieved, or internal communication between two elements; signal connection may refer to signal connection through a medium such as radio waves, in addition to signal connection through a circuit. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.
In order to make the person skilled in the art better understand the solution of the present utility model, the technical solution of the embodiment of the present utility model will be clearly and completely described below with reference to the accompanying drawings.
The embodiment of the utility model provides a power supply switching circuit. Referring to fig. 1, fig. 1 is a schematic structural diagram of a power switching circuit according to an embodiment of the present utility model. The power supply switching circuit includes: the power supply circuit comprises a first power supply circuit 10, a second power supply circuit 30 and a switch module 20, wherein the output end of the first power supply circuit 10 is electrically connected with the first end of the switch module 20, the output end of the second power supply circuit 30 is electrically connected with the second end of the switch module 20, and the third end of the switch module 20 is electrically connected with a load 40. The first power supply circuit 10 includes a first power supply VDD1, a voltage stabilizing module 11 and a first capacitor C1, where a first end of the voltage stabilizing module 11 is electrically connected to a first end of the switch module 20, the first end of the first capacitor C1 is electrically connected between the first end of the voltage stabilizing module 11 and the first end of the switch module 20, a second end of the voltage stabilizing module 11 and a second end of the first capacitor C1 are grounded, and a third end of the voltage stabilizing module 11 is electrically connected to the first power supply VDD 1.
The switch module 20 is used for conducting the first power supply circuit 10 and the load 40 or conducting the second power supply circuit 30 and the load 40.
The first power supply VDD1 is a dc power supply, and may be obtained by rectifying and filtering a commercial power, for example, the output voltage of the first power supply VDD1 is 12V. Under the condition that the mains supply is normally turned on, the voltage stabilizing module 11 may perform voltage reduction and voltage stabilization processing on the output voltage of the first power supply VDD1 to obtain a first output voltage V1, for example, the first output voltage V1 is 5.7V. In this way, the first power supply circuit 10 may generate the first output voltage V1 and provide the first output voltage V1 to the switching module 20.
The second power supply circuit 30 is, for example, a battery-powered circuit that can provide the second output voltage V2 to the switching module 20. For example, the second output voltage V2 is 3.6V.
The switch module 20, when the first power supply circuit 10 provides the load 40 with power, due to the voltage drop of the switch module 20, makes the input voltage of the load 40 lower than the first output voltage V1 of the first power supply circuit 10. For example, the input voltage of the load 40 is 5V. When the second power supply circuit 30 supplies power to the load 40, the input voltage of the load 40 is lower than the second output voltage V2 of the second power supply circuit 30 due to the voltage drop of the switch module 20. For example, the input voltage of the load 40 is 3.3V.
In the case of normal on of the mains supply, the switch module 20 may receive the first output voltage V1 provided by the first power supply circuit 10 and the second output voltage V2 provided by the second power supply circuit 30, and the first output voltage V1 is greater than the second output voltage V2, i.e. V1> V2. At this time, the switch module 20 may turn on the first power supply circuit 10 and the load 40, and disconnect the second power supply circuit 30 and the load 40, so that the utility power can provide power for the load 40.
In the case of power failure of the mains supply, the output voltage of the first power supply VDD1 decreases, and the corresponding first output voltage V1 also decreases. Referring to fig. 2, fig. 2 is a schematic diagram of a voltage when a mains supply is powered down according to an embodiment of the present utility model. In the case where the first output voltage V1 decreases, the input voltage of the load 40 also decreases, and when the input voltage of the load 40 is lower than the second output voltage V2, as shown in fig. 2. The switch module 20 turns on the second power supply circuit 30 and the load 40, and turns off the first power supply circuit 10 and the load 40, so that the second power supply circuit 30 can provide power for the load 40, and the input voltage of the load 40 is kept constant.
Under the condition that the mains supply is turned on again, the switch module 20 can receive the first output voltage V1 provided by the first power supply circuit 10, and at this time, the first output voltage V1 of the first power supply circuit 10 is greater than the input voltage of the load 40, and the switch module 20 automatically turns on the first power supply circuit 10 and the load 40, so that the mains supply provides the load 40 with electric energy again.
In summary, the switch module 20 conducts the first power supply circuit 10 and the load 40, or conducts the second power supply circuit 30 and the load 40, so that the first power supply circuit 10 and the second power supply circuit 30 can be automatically switched to provide the load 40 with electric energy.
In addition, during the process of switching the power supply of the load 40 from the first power supply circuit 10 to the second power supply circuit 30, the first capacitor C1 stores electric energy, and the first capacitor C1 releases the stored electric energy to enable the load 40 to continuously have the input voltage before the second power supply circuit 30 is conducted with the load 40. That is, before the second power supply circuit 30 is turned on with the load 40, the first power supply circuit 10 maintains the input voltage of the load 40 until the switch module 20 turns on the second power supply circuit 30 and the load 40. Therefore, before and after the second power supply circuit 30 is conducted with the load 40, the load 40 continuously has the input voltage, so that the two power supplies can be connected in a seamless manner in the switching process.
In this embodiment, the power supply switching circuit includes a first power supply circuit, a second power supply circuit and a switch module, where an output end of the first power supply circuit is electrically connected to a first end of the switch module, an output end of the second power supply circuit is electrically connected to a second end of the switch module, and a third end of the switch module is electrically connected to a load; the first power supply circuit comprises a first power supply, a voltage stabilizing module and a first capacitor, wherein the first end of the voltage stabilizing module is electrically connected with the first end of the first capacitor, the first end of the first capacitor is electrically connected between the first end of the voltage stabilizing module and the first end of the switch module, the second end of the voltage stabilizing module and the second end of the first capacitor are grounded, and the third end of the voltage stabilizing module is electrically connected with the first power supply; the first power supply circuit and the load are conducted through the switch module, or the second power supply circuit and the load are conducted, so that the first power supply circuit or the second power supply circuit provides electric energy for the load, and the intelligent electric energy meter can automatically switch between two power supplies. And in the process that the switch module switches the power supply of the load from the first power supply circuit to the second power supply circuit, as the first capacitor can store electric energy, the first power supply circuit continues to supply energy to the load until the second power supply circuit supplies energy to the load, so that in the switching process, the two power supplies can be connected in a seamless manner.
In some embodiments, referring to fig. 3, fig. 3 is a schematic diagram of another power switching circuit according to an embodiment of the present utility model. The voltage stabilizing module 11 includes a linear voltage stabilizer and a first diode D1, an output terminal of the linear voltage stabilizer is electrically connected to a first terminal of the switch module 20, a ground terminal of the linear voltage stabilizer is electrically connected to a first terminal of the first diode D1, an input terminal of the linear voltage stabilizer is electrically connected to the first power supply VDD1, and a second terminal of the first diode D1 is grounded.
With continued reference to fig. 3, the voltage regulator module 11 further includes a fourth diode D4, where a first end of the fourth diode D4 is electrically connected to the ground terminal of the linear voltage regulator and a first end of the first diode D1, respectively, and a second end of the fourth diode D4 is grounded.
The voltage at the second end of the first diode D1 is 0V, and the voltage drop of the first diode D1 is Vth, so that the voltage at the first end of the first diode D1 is equal to the voltage drop Vth of the first diode D1. For example, the voltage drop of the first diode D1 is 0.7V, and the voltage of the first terminal of the first diode D1 is 0.7V. Thus, the voltage at the ground terminal of the linear voltage regulator is Vth. That is, if the ground of the linear voltage regulator is grounded, the ground voltage Vth of the linear voltage regulator is 0V. If the ground terminal of the linear regulator is connected to the first diode D1, the first diode D1 raises the ground terminal voltage Vth of the linear regulator from 0V to 0.7V.
The linear voltage regulator may perform voltage reduction and stabilization processing on the output voltage of the first power supply VDD1, and obtain a reduced voltage V3 after voltage reduction and stabilization, where the reduced voltage V3 is a voltage with 0V as a reference. Since the first output voltage V1 outputted by the voltage stabilizing module 11 is a voltage with reference to the ground voltage Vth of the linear voltage stabilizer, v1=v3+vth. That is, the first diode D1 can raise the first output voltage V1. For example, based on the above embodiment, the ground voltage Vth of the linear regulator is 0.7V, the step-down voltage V3 is 5V, and the first output voltage V1 is 5.7V.
In summary, the combination of the linear voltage regulator and the first diode can raise the output voltage of the voltage regulator module 11 from the voltage-reduced voltage V3 to the first output voltage V1, that is, raise the output voltage of the first power supply circuit 10 from the voltage-reduced voltage V3 to the first output voltage V1. Thus, the output of the first output voltage V1 can be realized by adopting the existing device combination, and the cost of the circuit can be reduced without additionally designing devices.
As an example, with continued reference to fig. 3, the first power supply circuit 10 further includes a third capacitor C3, where a first end of the third capacitor C3 is electrically connected between the output terminal of the linear voltage regulator and the first end of the switch module 20, and a second end of the third capacitor C3 is grounded.
In the first power supply circuit 10, since the linear voltage regulator is far from the first power supply VDD1, the input voltage of the linear voltage regulator is greatly changed, and since the third capacitor C3 can function as a filter, the output voltage of the linear voltage regulator can be stabilized.
In some embodiments, with continued reference to fig. 3, the load 40 includes a micro-control unit and a plurality of load branches, and the third terminal of the switch module 20 is electrically connected to the first terminal of the micro-control unit and the plurality of load branches, respectively.
And the micro control unit is used for controlling part of all load branches to be not operated when the voltage of the third end of the voltage stabilizing module 11 is smaller than a threshold value, wherein the threshold value is larger than the output voltage of the first power supply circuit 10.
The connection mode of the micro control unit and the plurality of load branches may be electrical connection or wireless connection, and the connection mode of the micro control unit and the plurality of load branches is not particularly limited in the embodiment of the utility model.
In the case of power failure of the mains supply, the micro control unit receives the detection voltage, and since there is a linear proportional relationship between the detection voltage and the voltage of the third terminal of the voltage stabilizing module 11, for example, the product of the detection voltage and the proportionality coefficient a is the voltage of the third terminal of the voltage stabilizing module 11. The micro control unit can determine the magnitude of the voltage at the third terminal of the voltage stabilizing module 11 and the threshold value based on the magnitude of the detection voltage and the reference voltage. The linear proportional relationship between the threshold value and the reference voltage is the same as the linear proportional relationship between the detection voltage and the voltage of the third terminal of the voltage stabilizing module 11, for example, based on the above embodiment, the product of the threshold value and the scaling factor a is the reference voltage.
When the micro control unit determines that the detected voltage is smaller than the reference voltage, it may be determined that the voltage at the third end of the voltage stabilizing module 11 is smaller than the threshold, and at this time, the micro control unit controls a part of all load branches to be inoperative, so that a small number of load branches in the load operate, that is, the load performs a low power consumption mode. For example, only the load branches such as the control clock and the anti-theft switch are in operation.
Meanwhile, the threshold is typically a voltage value greater than the output voltage of the first power supply circuit 10, so that the micro control unit can have enough time to store data and control the load to enter the low power consumption mode before the voltage of the third terminal of the voltage stabilizing module 11 decreases to the output voltage of the first power supply circuit 10. In the case of power failure of the mains supply, a certain time is required for the voltage at the third terminal of the voltage stabilizing module 11 to decrease from the threshold value to the output voltage of the first power supply circuit 10, so that enough time is left for the micro control unit to store data and control the load to enter the low power consumption mode. For example, as shown in fig. 4, fig. 4 is a schematic diagram of another voltage when the mains supply is powered down, where 400ms, that is 282- (-140) ms is required for the voltage of the third terminal of the voltage stabilizing module 11 to decrease from 9V to 5.7V.
Illustratively, with continued reference to fig. 3, the power switching circuit further includes a voltage detection circuit 12, a first end of the voltage detection circuit 12 and a third end of the voltage stabilizing module 11 are electrically connected to the first power supply VDD1 through the same connection point B, and a second end of the voltage detection circuit 12 is electrically connected to a second end of the micro control unit.
The voltage detection circuit 12 is configured to detect a voltage of the third terminal of the voltage stabilizing module 11.
Illustratively, with continued reference to FIG. 3, the voltage detection circuit 12 includes a first resistor R1 and a second resistor R2, the first end of the first resistor R1 is electrically connected to the connection point B, the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2, the second end of the second resistor R2 is grounded, and the second end of the micro-control unit is electrically connected between the second end of the first resistor R1 and the first end of the second resistor R2.
The voltage at the first end of the first resistor R1 is U1, the voltage at the first end of the second resistor R2 is U2, the first resistor R1 and the second resistor R2 are connected in series, and the current of the second resistor R2 is equal to the current of the first resistor R1, namely U2/R 2 ＝(U1-U2)/R 1 Wherein R is 1 Is the resistance value of the first resistor R1, R 2 The resistance of the second resistor R2. Thus, u2=u1×r can be obtained 2 /(R 1 +R 2 ) Wherein R is 2 /(R 1 +R 2 ) It can be understood that the scaling factor a, the voltage detection circuit 12 may detect the voltage U1 at the third terminal of the voltage stabilizing module 11, to obtain the detected voltage U2.
Illustratively, with continued reference to FIG. 3, the voltage detection circuit 12 further includes a fourth capacitor C4, a first terminal of the fourth capacitor C4 being electrically connected between the second terminal of the first resistor R1 and the first terminal of the second resistor R2, a second terminal of the fourth capacitor C4 being grounded. Since the fourth capacitor C4 can perform a filtering function, the voltage at the first end of the second resistor R2 tends to be stable.
In this embodiment, the load includes a micro control unit and a plurality of load branches, and the third end of the switch module is electrically connected to the first end of the micro control unit and the plurality of load branches, respectively. When the voltage of the third end of the voltage stabilizing module is smaller than the threshold value, the micro control unit controls part of all load branches to be not operated, so that the running load branches are reduced, and the electric energy consumption is reduced.
In some embodiments, with continued reference to fig. 3, the voltage detection circuit 12 further includes a second capacitor C2, a first end of the second capacitor C2 is electrically connected to the connection point B, and a second end of the second capacitor C2 is grounded.
The second capacitor C2 is capable of storing electric energy, and in case of power failure of the mains supply, the second capacitor C2 releases electric energy to enable the voltage of the third terminal of the voltage stabilizing module 11 to slowly decrease, so that the output voltage of the first power supply circuit 10 slowly decreases until the switch module 20 conducts the second power supply circuit 30 and the load 40, and the second power supply circuit 30 provides electric energy for the load 40. In addition, under the condition of power failure of the mains supply, the second capacitor C2 maintains the voltage of the third terminal of the voltage stabilizing module 11 relatively stable, so that the voltage of the third terminal of the voltage stabilizing module 11 detected by the voltage detecting circuit 12 is relatively accurate.
In sum, the second capacitor provides electric energy for the voltage stabilizing module, so that the electric energy of the second power supply circuit is not consumed before the load enters the low-power consumption mode, the service life of the second power supply circuit can be prolonged, and the detection precision of the voltage of the third end of the voltage stabilizing module can be improved.
In some embodiments, with continued reference to fig. 3, the second power supply circuit 30 includes a second power supply VDD2, a first terminal of the second power supply VDD2 is electrically connected to a second terminal of the switch module 20, and a second terminal of the second power supply VDD2 is grounded.
As an example, with continued reference to fig. 3, the second power supply circuit 30 further includes a third resistor R3 and a fourth resistor R4, the first end of the third resistor R3 is electrically connected to the first end of the second power supply VDD2, the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is grounded, and the third end of the micro control unit is electrically connected between the second end of the third resistor R3 and the first end of the fourth resistor R4.
The micro control unit is further configured to detect whether the output voltage of the second power supply VDD2 is constant.
The output voltage of the second power supply VDD2 is U3, and the voltage of the first end of the fourth resistor R4 is U4. The third resistor R3 and the fourth resistor R4 are connected in series, so that the current of the third resistor R3 is equal to the current of the fourth resistor R4, namely U4/R 4 ＝(U3-U4)/R 3 Wherein R is 3 Is the resistance value of the third resistor R3, R 4 The resistance of the fourth resistor R4. Thus, u4=u3×r can be obtained 4 /(R 3 +R 4 ) Micro-scaleThe control unit may detect whether the output voltage of the second power supply VDD2 is constant by detecting whether the voltage of the first terminal of the fourth resistor R4 is constant.
As shown in fig. 3, the second power supply circuit 30 further includes a fifth capacitor C5, where a first end of the fifth capacitor C5 is electrically connected between a second end of the third resistor R3 and a first end of the fourth resistor R4, and a second end of the fifth capacitor C5 is grounded. Since the fifth capacitor C5 can perform a filtering function, the voltage at the first end of the fourth resistor R4 tends to be stable.
In this embodiment, the second power supply provides the electric energy for the load, so that the complexity of the second power supply circuit is reduced, and the production cost is low.
In some embodiments, with continued reference to fig. 3, the switch module 20 includes a second diode D2 and a third diode D3, the first end of the second diode D2 is electrically connected to the output of the first power supply circuit 10, the first end of the third diode D3 is electrically connected to the output of the second power supply circuit 30, and the second end of the second diode D2 and the second end of the third diode D3 are both electrically connected to the load 40.
Under the condition that the mains supply is normally turned on, since the first output voltage V1 of the first power supply circuit 10 is greater than the second output voltage V2 of the second power supply circuit 30, the second diode D2 turns on the first power supply circuit 10 and the load 40, and the third diode D3 turns off the second power supply circuit 30 and the load 40, so that the mains supply can provide electric energy for the load 40. When the mains supply is powered down, the first output voltage V1 of the first power supply circuit 10 gradually decreases, and when the first output voltage V1 of the first power supply circuit 10 gradually decreases, the input voltage of the load 40 also gradually decreases, and when the input voltage of the load 40 is lower than the second output voltage V2 of the second power supply circuit 30, the third diode D3 automatically turns on the second power supply circuit 30 and the load 40, and the second diode D2 disconnects the first power supply circuit 10 and the load 40, so that the second power supply circuit 30 provides the load 40 with electric energy.
In sum, the second diode is used for controlling the on-off of the first power supply circuit and the load, and the third diode is used for controlling the on-off of the second power supply circuit and the load, so that the control logic is simple and the operability is strong.
The embodiment of the utility model also provides an intelligent electric energy meter. The intelligent ammeter comprises a load and the power supply switching circuit in the previous embodiment. Since the structure and the beneficial effects of the power switching circuit are described in detail in the foregoing embodiments, the present utility model is not repeated here.
In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The utility model may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of first, second, third, etc. does not denote any order, and the words are to be interpreted as names. The steps in the above embodiments should not be construed as limiting the order of execution unless specifically stated.
The above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.
Claims (9)
1. The power supply switching circuit is characterized by comprising a first power supply circuit, a second power supply circuit and a switch module, wherein the output end of the first power supply circuit is electrically connected with the first end of the switch module, the output end of the second power supply circuit is electrically connected with the second end of the switch module, and the third end of the switch module is electrically connected with a load;
the first power supply circuit comprises a first power supply, a voltage stabilizing module and a first capacitor, wherein the first end of the voltage stabilizing module is electrically connected with the first end of the switch module, the first end of the first capacitor is electrically connected between the first end of the voltage stabilizing module and the first end of the switch module, the second end of the voltage stabilizing module and the second end of the first capacitor are grounded, and the third end of the voltage stabilizing module is electrically connected with the first power supply;
the switch module is used for conducting the first power supply circuit and the load or conducting the second power supply circuit and the load;
the load comprises a micro control unit and a plurality of load branches, and a third end of the switch module is respectively and electrically connected with a first end of the micro control unit and the load branches;
and the micro control unit is used for controlling part of all the load branches to be not operated when the voltage of the third end of the voltage stabilizing module is smaller than a threshold value, wherein the threshold value is larger than the output voltage of the first power supply circuit.
2. The power switching circuit according to claim 1, further comprising a voltage detection circuit, wherein a first end of the voltage detection circuit and a third end of the voltage stabilizing module are electrically connected to the first power supply through a same connection point, and a second end of the voltage detection circuit is electrically connected to a second end of the micro control unit;
the voltage detection circuit is used for detecting the voltage of the third end of the voltage stabilizing module.
3. The power switching circuit of claim 2, wherein the voltage detection circuit comprises a first resistor and a second resistor, a first end of the first resistor is electrically connected to the connection point, a second end of the first resistor is electrically connected to a first end of the second resistor, a second end of the second resistor is grounded, and a second end of the micro control unit is electrically connected between the second end of the first resistor and the first end of the second resistor.
4. The power switching circuit of claim 3 wherein the voltage detection circuit further comprises a second capacitor, a first end of the second capacitor being electrically connected to the connection point, a second end of the second capacitor being grounded.
5. The power switching circuit of claim 1, wherein the voltage regulator module comprises a linear voltage regulator and a first diode, an output terminal of the linear voltage regulator is electrically connected to the first terminal of the switch module, a ground terminal of the linear voltage regulator is electrically connected to the first terminal of the first diode, an input terminal of the linear voltage regulator is electrically connected to the first power supply, and a second terminal of the first diode is grounded.
6. The power switching circuit of claim 1, wherein the second power supply circuit comprises a second power supply having a first end electrically connected to the second end of the switch module and a second end grounded.
7. The power switching circuit according to claim 6, wherein the second power supply circuit further comprises a third resistor and a fourth resistor, a first end of the third resistor is electrically connected to a first end of the second power supply, a second end of the third resistor is electrically connected to a first end of the fourth resistor, a second end of the fourth resistor is grounded, and a third end of the micro control unit is electrically connected between the second end of the third resistor and the first end of the fourth resistor;
the micro control unit is also used for detecting whether the output voltage of the second power supply is constant.
8. The power switching circuit according to any one of claims 1-7, wherein the switching module comprises a second diode and a third diode, a first end of the second diode is electrically connected to the output of the first power supply circuit, a first end of the third diode is electrically connected to the output of the second power supply circuit, and a second end of the second diode and a second end of the third diode are both electrically connected to the load.
9. An intelligent electric energy meter comprising a load and a power switching circuit as claimed in any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320995876.9U CN219843456U (en) | 2023-04-26 | 2023-04-26 | Power supply switching circuit and intelligent electric energy meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320995876.9U CN219843456U (en) | 2023-04-26 | 2023-04-26 | Power supply switching circuit and intelligent electric energy meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219843456U true CN219843456U (en) | 2023-10-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320995876.9U Active CN219843456U (en) | 2023-04-26 | 2023-04-26 | Power supply switching circuit and intelligent electric energy meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219843456U (en) |
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2023
- 2023-04-26 CN CN202320995876.9U patent/CN219843456U/en active Active
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