Multiplexing circuit for output terminal of electric energy meter

Abstract

The invention provides a multiplexing circuit for an output terminal of an electric energy meter, and the circuit comprises a control pin K1 which is controlled by a CPU of the electric energy meter and is used for controlling an output signal of a multiplexing terminal; the base electrode of the PNP triode Q1 is connected to the resistor R1, the emitter electrode of the PNP triode Q1 is connected to a metering pulse signal PULSE, and the collector electrode of the PNP triode Q1 is connected to the negative electrode of the diode D1 and one end of the resistor R2; a control end ctr of the clock chip U1 is connected to the control pin K1, and a second signal output pin sec is connected to the other end of the resistor R2; and a pin 1 of the optocoupler U2 is connected to the resistor R2, a pin 2 is grounded, and a pin 3 and a pin 4 are connected to an output multiplexing terminal of the electric energy meter. According to the multiplexing circuit, the metering pulse signal and the clock second signal are multiplexed to one group of output terminals, so that the number of terminals of the electric energy meter is remarkably reduced. The design not only reduces the material cost of hardware, but also reduces the occupied space of a circuit board, thereby reducing the complexity of production and assembly.

Description

Technical Field

[0001] The invention relates to the technical field of multiplexing circuits, in particular to a multiplexing circuit for output terminals of an electric energy meter. Background Art

[0002] The electric energy meter is a key device in the power system, used to measure the consumption of electricity. With the advancement of science and technology and the development of society, the functions of the electric energy meter are constantly enriched, and its accuracy, reliability and intelligence are also constantly improving. In the production process of the electric energy meter, in order to ensure the accuracy of its measurement, it is usually necessary to calibrate multiple output signals. In the traditional design of electric energy meters, each output signal is often transmitted through a separate terminal, which has some problems and challenges.

[0003] First, the multi-terminal design increases the complexity and manufacturing cost of the energy meter. Each additional terminal requires corresponding circuit design and physical space to be arranged, which not only increases the number and cost of components, but also puts higher requirements on circuit board design and assembly. For high-precision instruments such as energy meters, multi-terminal design may also bring more potential failure points, affecting product reliability.

[0004] Secondly, the presence of multiple terminals makes it difficult to further reduce the size of the energy meter. With the popularization of smart grids and smart homes, the size of energy meters is required to be increasingly miniaturized so that they can be installed in various compact environments. However, the multi-terminal design not only increases the shell size of the energy meter, but also increases the complexity of the internal circuit, making miniaturization difficult to achieve. In addition, multi-terminal connection also increases the difficulty of installation and maintenance, and may require more wiring and connectors, which also increases the workload and cost during on-site installation and subsequent maintenance.

[0005] In addition, in some specific application scenarios, such as remote meter reading and load management of smart grids, energy meters need to support more functions and interfaces, such as data communication, remote control, and measurement of multiple power parameters. The realization of these functions often requires more input and output interfaces. If the traditional multi-terminal design is continued, the above problems will be further aggravated.

[0006] In view of the above problems, an effective solution is to use a multiplexing circuit to output multiple signals through the same terminal. This design can not only reduce the number of terminals and simplify the circuit structure, but also effectively reduce costs and improve the integration and reliability of the energy meter. By controlling the switches and logic levels in the circuit, different signals can be flexibly selected for output, such as metering pulse signals, clock second signals, etc. The introduction of the multiplexing circuit not only reduces the occupation of hardware resources, but also makes it possible to design the energy meter in a miniaturized manner.

[0007] The realization of multiplexing circuits usually relies on the development of modern electronic technology, such as CMOS technology, low-power design, and high-precision clock technology. Through these technologies, efficient signal switching and isolation can be achieved to ensure that no interference is generated during the switching of different signals, and the integrity and accuracy of the signal are maintained. For example, the use of optocouplers can achieve electrical isolation of signals, prevent signals from interfering with each other, and ensure high voltage safety. For another example, the use of basic components such as transistors and diodes can achieve switch control and direction control of signals.

[0008] In recent years, with the rapid development of the Internet of Things (IoT) and smart homes, the functions of electric energy meters are not limited to traditional power consumption measurement, but have gradually expanded to areas such as intelligent control and data communication. The realization of these new functions also requires more interfaces and more complex signal processing capabilities. The application of multiplexing circuits can not only meet the needs of these new functions, but also achieve more functional expansion through software updates, such as remote firmware upgrades, dynamic parameter adjustments, etc.

[0009] In summary, the design and application of multiplexing circuits has become an important direction in the design of modern electric energy meters. It not only helps to reduce costs and simplify structures, but also provides strong support for the miniaturization, intelligence and multi-function of electric energy meters. With the continuous advancement of electronic technology, the design of multiplexing circuits will become more mature and diversified, opening up new prospects for the development of electric energy meters. Summary of the invention

[0010] The object of the present invention is to provide a multiplexing circuit for output terminals of an electric energy meter to solve the problems raised by the above background technology.

[0011] To achieve the above object, the present invention provides the following technical solution: a multiplexing circuit for output terminals of an electric energy meter, the circuit comprising: Control pin K1 is controlled by the energy meter CPU and is used to control the output signal of the multiplexed terminal; A PNP transistor Q1, whose base is connected to the resistor R1, whose emitter is connected to the metering pulse signal PULSE, and whose collector is connected to the cathode of the diode D1 and one end of the resistor R2; The clock chip U1 has a control terminal ctr connected to the control pin K1, and a second signal output pin sec connected to the other end of the resistor R2; Optocoupler U2, pin 1 is connected to resistor R2, pin 2 is grounded, and pins 3 and 4 are connected to the output multiplexing terminal of the energy meter.

[0012] As a preferred technical solution of the present invention, when the control pin K1 is at a low level, the PNP transistor Q1 is turned on, and the multiplexing terminal outputs a metering pulse signal PULSE.

[0013] As a preferred technical solution of the present invention, when the control pin K1 is at a low level, the second signal output sec of the clock chip U1 is in a high-impedance state.

[0014] As a preferred technical solution of the present invention, when the control pin K1 is at a high level, the PNP transistor Q1 is turned off, and the multiplexing terminal outputs the second signal of the clock chip U1.

[0015] As a preferred technical solution of the present invention, when the control pin K1 is at a high level, the second signal output pin sec of the clock chip U1 drives the optocoupler U2 through the current provided by the resistor R2.

[0016] As a preferred technical solution of the present invention, the anode of the diode D1 is connected to the control pin K1, so as to transmit a high level to the resistor R2 when the control pin K1 is at a high level.

[0017] As a preferred technical solution of the present invention, the optical coupler U2 is used to isolate the output signal of the metering pulse signal PULSE and the clock second signal to ensure the stability of signal transmission.

[0018] Compared with the prior art, the beneficial effect of the present invention is that the multiplexing circuit of the present invention significantly reduces the number of terminals of the electric energy meter by multiplexing the metering pulse signal and the clock second signal to a group of output terminals. This design not only reduces the material cost of the hardware, but also reduces the space occupied by the circuit board, thereby reducing the complexity of production and assembly. In addition, the reduced number of terminals also means that the potential failure points are reduced, and the overall reliability of the product is improved. For large-scale production of electric energy meter products, this cost and resource saving effect is particularly significant, which helps to improve market competitiveness.

[0019] The application of multiplexing circuits makes the overall design of the energy meter more concise and compact, meeting the design requirements of miniaturization. This is especially important for the application of energy meters in modern smart grids and smart home systems. The miniaturization design not only facilitates the installation and layout of the energy meter, but also provides the possibility of installation in a small space. At the same time, the smaller device size makes the energy meter more beautiful in appearance design, adapting to the needs of more modern scenarios and improving user experience.

[0020] By controlling the logic level in the circuit, the multiplexing circuit can flexibly switch and output different signal types, such as metering pulse signals and clock second signals. This design not only improves the functional integration of the energy meter, but also facilitates the expansion of future functions. For example, new signal output functions can be flexibly added through software control or firmware updates without changing the hardware. This high flexibility and scalability enables the energy meter to better adapt to the needs of different application scenarios, such as remote meter reading, load management and other intelligent functions, providing strong support for the intelligence and automation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a circuit diagram of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example: Basic multiplexing circuit design like Figure 1 As shown, a multiplexing circuit of the present invention includes: Control pin (K1): A control pin from the energy meter CPU, used to control the output state of the multiplexed terminal. When the control pin is at a low level, the multiplexed terminal outputs a metering pulse signal; when the control pin is at a high level, the multiplexed terminal outputs the second signal of the clock.

[0024] PNP transistor (Q1): Its base is connected to the resistor (R1), the emitter is connected to the metering pulse signal (PULSE), and the collector is connected to the cathode of the diode (D1) and one end of the resistor (R2). The level change of the control pin K1 controls the conduction of Q1, thereby realizing the selective output of the signal.

[0025] Optocoupler (U2): used for signal isolation and transmission. When Q1 is turned on, current flows between pins 1 and 2 of the optocoupler U2, and pins 3 and 4 of U2 are turned on, thus realizing the transmission of the metering pulse signal.

[0026] Clock chip (U1): The control pin ctr is connected to K1, which is used to output the second signal. When K1 is high, the second signal output pin sec of U1 enters the open-drain state and outputs the second signal to the multiplex terminal.

[0027] The circuit realizes the multiplexed output of the metering pulse signal and the clock second signal by switching the level of the control pin K1, reducing the number of terminals of the electric energy meter and meeting the design requirements of miniaturization and low cost.

[0028] This design can effectively reduce the impact of ambient temperature changes on the measurement accuracy of the electric energy meter and improve the overall performance of the electric energy meter.

[0029] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multiplexing circuit for output terminals of an electric energy meter, characterized in that: The circuit includes: Control pin K1 is controlled by the energy meter CPU and is used to control the output signal of the multiplexed terminal; A PNP transistor Q1, whose base is connected to the resistor R1, whose emitter is connected to the metering pulse signal PULSE, and whose collector is connected to the cathode of the diode D1 and one end of the resistor R2; The clock chip U1 has a control terminal ctr connected to the control pin K1, and a second signal output pin sec connected to the other end of the resistor R2; Optocoupler U2, pin 1 is connected to resistor R2, pin 2 is grounded, and pins 3 and 4 are connected to the output multiplexing terminal of the energy meter.

2. A multiplexing circuit for output terminals of an electric energy meter according to claim 1, characterized in that: When the control pin K1 is at a low level, the PNP transistor Q1 is turned on, and the multiplexing terminal outputs a metering pulse signal PULSE.

3. A multiplexing circuit for output terminals of an electric energy meter according to claim 2, characterized in that: When the control pin K1 is at a low level, the second signal output sec of the clock chip U1 is in a high-impedance state.

4. A multiplexing circuit for output terminals of an electric energy meter according to claim 1, characterized in that: When the control pin K1 is at a high level, the PNP transistor Q1 is turned off, and the multiplexing terminal outputs the second signal of the clock chip U1.

5. A multiplexing circuit for output terminals of an electric energy meter according to claim 4, characterized in that: When the control pin K1 is at a high level, the second signal output pin sec of the clock chip U1 drives the optocoupler U2 through the current provided by the resistor R2.

6. A multiplexing circuit for output terminals of an electric energy meter according to claim 1, characterized in that: The anode of the diode D1 is connected to the control pin K1, and is used to transmit a high level to the resistor R2 when the control pin K1 is at a high level.

7. A multiplexing circuit for output terminals of an electric energy meter according to claim 1, characterized in that: The optical coupler U2 is used to isolate the output signals of the metering pulse signal PULSE and the clock second signal to ensure the stability of signal transmission.

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