Power acquisition circuit with adjustable measuring range and power meter

Abstract

The utility model relates to a power acquisition circuit with adjustable measuring range and a power meter, the power acquisition circuit comprises a control module, a measuring range switching module and an electric energy measuring module, the measuring range switching module comprises an analog switch and a multi-contact relay, the input end of the analog switch is connected with the control module, and the input end of the multi-contact relay is connected with the control module. The output end of the analog switch is connected with a coil of the multi-contact relay, a normally closed contact of the multi-contact relay is connected with a first sampling resistor, a normally open contact of the multi-contact relay is connected with a second sampling resistor, and a movable contact of the multi-contact relay is connected with a load electric appliance; the electric energy measurement module comprises a current acquisition circuit, a voltage acquisition circuit and an electric energy measurement chip. According to the power acquisition circuit of the utility model, the load electric appliance is connected in series with the first sampling resistor by default, and after the control module sends a control signal to the analog switch, the load electric appliance is connected in series with the second sampling resistor, thereby realizing range switching.

Description

Technical Field

[0001] This utility model relates to the field of electrical energy detection technology, and in particular to an adjustable range power acquisition circuit and a power meter. Background Technology

[0002] Currently, the measurement range of power acquisition circuits is generally fixed. To ensure the accuracy of power measurement, the range of power acquisition circuits is usually not large enough. This necessitates designing multiple power acquisition circuits with different ranges for appliances with varying power levels, increasing design and manufacturing costs. Conversely, increasing the range individually can lead to insufficient accuracy when measuring low-power appliances. Although there are power acquisition circuit solutions with multiple ranges in related technologies, most have complex circuit structures and high manufacturing costs. Utility Model Content

[0003] To address at least one of the aforementioned technical problems, this utility model proposes an adjustable range power acquisition circuit and a power meter.

[0004] According to some embodiments of this utility model, an adjustable range power acquisition circuit is provided. The power acquisition circuit includes a control module, a range switching module, and an energy measurement module. The range switching module includes an analog switch and a multi-contact relay. The input terminal of the analog switch is connected to the control module, and the output terminal of the analog switch is connected to the coil of the multi-contact relay. The normally closed contact of the multi-contact relay is connected to a first terminal of a first sampling resistor, and the second terminal of the first sampling resistor is grounded. The normally open contact of the multi-contact relay is connected to a first terminal of a second sampling resistor, and the second terminal of the second sampling resistor is grounded. The moving contact of the multi-contact relay is connected to a load appliance. The energy measurement module includes a current acquisition circuit, a voltage acquisition circuit, and an energy measurement chip. One end of the voltage acquisition circuit is connected to the load appliance, and the other end of the voltage acquisition circuit is connected to the energy measurement chip. One end of the current acquisition circuit is connected to the moving contact of the multi-contact relay, and the other end of the current acquisition circuit is connected to the energy measurement chip.

[0005] Based on the above scheme, the power measurement module obtains the voltage parameters of the load device through the voltage acquisition circuit, obtains the current parameters of the load device through the current acquisition circuit in conjunction with the sampling resistor, and determines the power of the load device through the power measurement chip. The load device is connected in series with the first sampling resistor by default. After the control module sends a control signal to the analog switch, the load device is changed to be connected in series with the second sampling resistor, thereby realizing the range switching.

[0006] In some possible implementations, the power acquisition circuit further includes a differential analog-to-digital converter (ADC), with a first input terminal connected to the moving contact of the multi-contact relay, a second input terminal connected to the second terminals of the first and second sampling resistors respectively, and the input terminal of the differential ADC connected to the control module.

[0007] Based on the above scheme, by setting a differential analog-to-digital converter, the voltage across the sampling resistor can be directly acquired and converted into a digital signal. The control module directly determines whether the voltage of the sampling resistor is within the preset range based on the digital signal, so as to determine whether the current range is appropriate and whether the range needs to be switched, thereby achieving the effect of automatic switching.

[0008] In some possible implementations, the control module includes a microcontroller that integrates the differential analog-to-digital converter.

[0009] Based on the above solution, by selecting a microcontroller with an integrated differential analog-to-digital converter as the control module, the overall circuit structure can be simplified, and the circuit cost can also be reduced.

[0010] In some possible implementations, the power acquisition circuit further includes a voltage detection module, the input of which is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively, and the output of which is connected to the control module.

[0011] Based on the above scheme, by setting up a voltage detection module, the voltage across the sampling resistor can be directly obtained, and voltage detection can be achieved using analog circuits without analog-to-digital conversion.

[0012] In some possible implementations, the voltage detection module includes a first voltage comparator and a second voltage comparator. The first input terminal of the first voltage comparator is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively. The second input terminal of the first voltage comparator is connected to a first voltage signal source, and the output terminal of the first voltage comparator is connected to the control module. The first input terminal of the second voltage comparator is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively. The second input terminal of the second voltage comparator is connected to a second voltage signal source, and the output terminal of the second voltage comparator is connected to the control module.

[0013] Based on the above scheme, by setting two voltage comparators, which correspond to the minimum threshold and the maximum threshold respectively, it is possible to determine whether the voltage across the sampling resistor is within the threshold range. The control module then confirms whether the current range is appropriate based on the output results of the two voltage comparators and outputs the corresponding signal to the analog switch.

[0014] In some possible implementations, the power acquisition circuit further includes a power supply module, the input of which is connected to an AC power source, and the output of which is connected to the control module, the range switching module, the voltage detection module, and the energy measurement module, respectively.

[0015] Based on the above solution, the power module with rectification function is integrated into the power acquisition circuit, eliminating the need for an additional DC power supply and facilitating the modular design of the power acquisition circuit.

[0016] In some possible implementations, the power module further includes multiple output ports, the output voltage of which is adjustable, and the second input terminal of the first voltage comparator and the second input terminal of the second voltage comparator are respectively connected to two output ports of the power module.

[0017] Based on the above scheme, the power supply module is a multi-channel adjustable DC power supply. The output voltages of multiple output ports are independent and adjustable, which helps to change the reference voltage signals of the two voltage comparators, thereby changing the voltage detection threshold range.

[0018] In some possible implementations, the current acquisition circuit includes a differential amplifier circuit, which includes a first resistor, a first capacitor, a second capacitor, and a second resistor connected in sequence. The end of the first resistor away from the first capacitor is connected to the first end of the branch where the relay contacts are located, and the end of the first resistor close to the first capacitor is connected to the power measurement chip. The end of the second resistor away from the second capacitor is connected to the second end of the branch where the relay contacts are located, and the end of the second resistor close to the second capacitor is connected to the power measurement chip. The end of the first capacitor connected to the second capacitor is grounded.

[0019] Based on the above scheme, the differential amplifier circuit can convert the current signal into a voltage signal, which is convenient for the power measurement chip to read and identify.

[0020] In some possible implementations, the power acquisition circuit further includes a display module connected to the control module, the display module being used to display the current range of the power acquisition circuit and the power parameters of the load appliance.

[0021] Based on the above solution, setting up a display module helps to provide feedback on range information and test information, thereby enhancing the user experience.

[0022] According to some other embodiments of the present invention, a power meter is provided, including an adjustable range power acquisition circuit as described in any of the above embodiments.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the present invention.

[0024] Other features and aspects of the present invention will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions and advantages in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A structural block diagram of an adjustable range power acquisition circuit according to an embodiment of the present invention is shown.

[0027] Figure 2 This diagram shows a first circuit structure of an adjustable range power acquisition circuit according to an embodiment of the present invention.

[0028] Figure 3 This diagram shows a second circuit structure of an adjustable-range power acquisition circuit according to an embodiment of the present invention.

[0029] Figure 4 A third circuit structure diagram of an adjustable range power acquisition circuit according to an embodiment of the present invention is shown.

[0030] Figure 5 This diagram shows a fourth circuit structure of an adjustable range power acquisition circuit according to an embodiment of the present invention.

[0031] Figure 6 A circuit diagram of a differential amplifier circuit according to an embodiment of the present invention is shown.

[0032] In the picture,

[0033] 1. Control module; 2. Analog switch; 3. Multi-contact relay; 31. First sampling resistor; 32. Second sampling resistor; 4. Power measurement chip; 5. Current acquisition circuit; 51. First resistor; 52. First capacitor; 53. Second capacitor; 54. Second resistor; 6. Voltage acquisition circuit; 7. Differential analog-to-digital converter; 8. Voltage detection module; 81. First voltage comparator; 82. Second voltage comparator. Detailed Implementation

[0034] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0036] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0037] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0038] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0039] Furthermore, to better illustrate this utility model, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this utility model can be implemented without certain specific details. In some instances, methods, means, components, and circuits well-known to those skilled in the art have not been described in detail in order to highlight the main points of this utility model.

[0040] Please refer to Figures 1-2 This utility model embodiment provides an adjustable range power acquisition circuit, which includes: a control module 1, a range switching module, and an energy measurement module. The control module 1 is connected to both the range switching module and the energy measurement module. The range switching module has two sampling resistors with different resistance values. The control module 1 controls one of the sampling resistors in the range switching module to connect to the load appliance. The energy measurement module directly measures the voltage parameters of the load appliance, then obtains the current parameters of the load appliance through the sampling resistor, and calculates the power of the load appliance based on the voltage and current parameters.

[0041] Specifically, the range switching module includes an analog switch 2 and a multi-contact relay 3. The input terminal of the analog switch 2 is connected to the control module 1, and the output terminal of the analog switch 2 is connected to the coil of the multi-contact relay 3. The normally closed contact of the multi-contact relay 3 is connected to the first terminal of the first sampling resistor 31, and the second terminal of the first sampling resistor 31 is grounded. The normally open contact of the multi-contact relay 3 is connected to the first terminal of the second sampling resistor 32, and the second terminal of the second sampling resistor 32 is grounded. The moving contact of the multi-contact relay 3 is connected to the load appliance. The power measurement module includes a current acquisition circuit 5, a voltage acquisition circuit 6, and a power measurement chip 4. One end of the voltage acquisition circuit 6 is connected to the load appliance, and the other end of the voltage acquisition circuit 6 is connected to the power measurement chip 4. One end of the current acquisition circuit 5 is connected to the moving contact of the multi-contact relay 3, and the other end of the current acquisition circuit 5 is connected to the power measurement chip 4.

[0042] Based on the above circuit structure, the load device is connected in series with the sampling resistor. The current of the sampling resistor is the same as the current of the load device. Therefore, the current acquisition circuit 5 is connected to the sampling resistor to obtain the current parameter of the sampling resistor, and thus the current parameter of the load device can be obtained. The voltage acquisition circuit 6 is connected to the load device to obtain the voltage parameter of the load device. The power measurement chip 4 determines the power of the load device based on the obtained current and voltage parameters and sends the power data to the control module 1. The moving contact of the multi-contact relay 3 is connected to the normally closed contact in the default state, that is, the load device is initially connected to the first sampling resistor 31. After the control module 1 sends a control signal to the analog switch 2, the analog switch 2 is turned on, which energizes the coil in the multi-contact relay 3. Under the electromagnetic induction of the coil, the moving contact is disconnected from the normally closed contact and connected to the normally open contact. Correspondingly, the load device disconnects from the first sampling resistor 31 and switches to series connection with the second sampling resistor 32, thereby completing the range switching.

[0043] This embodiment does not limit the selection of analog switch 2. That is to say, analog switch 2 can be a transistor switch, MOSFET (metal-oxide-semiconductor field-effect transistor) switch, CMOS (complementary metal-oxide-semiconductor) switch, bidirectional diode switch, etc.

[0044] In one specific embodiment, please refer to Figure 2 Analog switch 2 uses a BJT (bipolar junction transistor). The collector of the transistor is connected to one end of the coil of the multi-contact relay 3, and the other end of the coil is connected to a DC voltage source. A protection diode is also provided at both ends of the coil. The base of the transistor is connected to the control module 1, and the emitter of the transistor is grounded. Using a BJT in analog switch 2 simplifies the circuit structure, reduces circuit cost, and is easy to manufacture.

[0045] In this embodiment, the control module 1 can send control signals to the range switching module according to certain rules to switch the sampling resistor connected to the load appliance, thereby realizing the function of automatic range switching. For example, the control module 1 obtains the power data of the load appliance from the power measurement chip 4, and then compares the power data with the current range to confirm whether the current range is appropriate. If the power of the load appliance is not within the current range, the control module 1 sends a control signal, and the range switching module switches the sampling resistor connected to the load appliance to complete the range switching.

[0046] In some embodiments, please refer to Figure 3 The power acquisition circuit also includes a differential analog-to-digital converter 7. The first input terminal of the differential analog-to-digital converter 7 is connected to the moving contact of the multi-contact relay 3. The second input terminal of the differential analog-to-digital converter 7 is connected to the second terminal of the first sampling resistor 31 and the second terminal of the second sampling resistor 32, respectively. The input terminal of the differential analog-to-digital converter 7 is connected to the control module 1.

[0047] This embodiment can be applied to the power measurement of household appliances. Since the voltage standard of household appliances is standard voltage, the power is positively correlated with the current. With the resistance of the sampling resistor remaining constant, the greater the power of the load appliance, the greater the current. Correspondingly, the voltage across the sampling resistor is also greater. Therefore, the differential analog-to-digital converter 7 samples the voltage across the sampling resistor and converts it into a digital signal. The control module 1 directly calculates and identifies the signal based on the digital signal to determine whether the current measurement range is appropriate. Specifically, sampling resistors with different resistance values ​​have an independent voltage detection range, which corresponds to the current measurement range. If the voltage across the sampling resistor is not within the voltage detection range, it indicates that the current measurement range is inappropriate. The controller sends a control signal based on the detection result to automatically switch the measurement range.

[0048] Based on the above embodiments, the control module 1 further includes a microcontroller, which integrates a differential analog-to-digital converter 7. In other words, configuring the control module 1 with a microcontroller that integrates a differential analog-to-digital converter 7 helps simplify the overall circuit structure, reduces circuit size, and lowers circuit cost.

[0049] In other embodiments, the power module can also directly acquire the voltage across the sampling resistor and complete voltage detection via analog circuitry. For details, please refer to... Figure 4 The power acquisition circuit also includes a voltage detection module 8. The input terminals of the voltage detection module 8 are connected to the normally closed and normally open contacts of the multi-contact relay 3, respectively, and the output terminal of the voltage detection module 8 is connected to the control module 1. The voltage detection module 8 can be implemented based on a voltage comparator. By setting a voltage comparator, it is determined whether the voltage across the sampling resistor is greater than the reference voltage. If it is not greater than the reference voltage, the voltage comparator does not output a feedback signal; if it is greater than the reference voltage, the voltage comparator outputs a feedback signal. In response to the feedback signal of the voltage comparator, the control module 1 sends a control signal to the range switching module to complete the switching of the sampling resistor and the change of the measurement range.

[0050] In a further embodiment, the voltage detection module 8 includes two voltage comparators, which enable range voltage detection. Specifically, please refer to... Figure 5The voltage detection module 8 includes a first voltage comparator 81 and a second voltage comparator 82. The first input terminal of the first voltage comparator 81 is connected to the normally closed contact and the normally open contact of the multi-contact relay 3, respectively. The second input terminal of the first voltage comparator 81 is connected to a first voltage signal source, and the output terminal of the first voltage comparator 81 is connected to the control module 1. The first input terminal of the second voltage comparator 82 is connected to the normally closed contact and the normally open contact of the multi-contact relay 3, respectively. The second input terminal of the second voltage comparator 82 is connected to a second voltage signal source, and the output terminal of the second voltage comparator 82 is connected to the control module 1. The first voltage comparator 81 corresponds to the minimum threshold of the voltage detection range. When the voltage across the sampling resistor is less than the minimum threshold, the first voltage comparator 81 outputs a feedback signal. The second voltage comparator 82 corresponds to the maximum threshold of the voltage detection range. When the voltage across the sampling resistor is greater than the minimum threshold, the second voltage comparator 82 outputs a feedback signal. After receiving the feedback signal from either comparator, the control module 1 sends a control signal to the range switching module to complete the sampling resistor switching and range change.

[0051] In this invention, the power acquisition circuit requires a DC power supply to power the control module 1, range switching module, voltage detection module 8, and energy measurement module. The load device is connected to an AC power supply. To further simplify the circuit structure, in some embodiments, the power acquisition circuit also includes a power supply module. The input terminal of the power supply module is connected to the AC power supply, and the output terminal of the power supply module is connected to the control module 1, range switching module, voltage detection module 8, and energy measurement module, respectively. Based on the power supply module, the power acquisition circuit can be modularly configured. Specifically, it can be designed as a two-port circuit, with one end for connecting to the AC power supply and the other end for connecting to the load device.

[0052] In a further embodiment, please refer to Figure 5 The power module also includes multiple output ports, the output voltage of which is adjustable. The second input terminal of the first voltage comparator 81 and the second input terminal of the second voltage comparator 82 are respectively connected to two output ports of the power module. Based on the above configuration, the power module is a multi-channel adjustable power supply, and the output voltages of the multiple output ports are independent and adjustable, which helps to change the reference voltage signals of the two voltage comparators, thereby changing the voltage detection threshold range.

[0053] In this invention, the specific structure of the acquisition circuit and the voltage acquisition circuit 6 is not limited. For example, the current acquisition circuit 5 can be a detection circuit based on a shunt or a detection circuit based on a coil current transformer; the voltage acquisition circuit 6 can be a detection circuit based on the voltage divider principle, a detection circuit based on a Hall sensor, or a detection circuit based on a capacitively coupled sensor, etc. Furthermore, this embodiment does not limit the specific signal of the power measurement chip 4; the power measurement chip 4 can be BL0942, AD71056, HLW8032, or other types of chips.

[0054] In some embodiments, please refer to Figure 6 The current acquisition circuit 5 includes a differential amplifier circuit, the input port of which is connected across the sampling resistor. Acquiring the current information of the electrical appliance based on the differential amplifier circuit reduces power supply fluctuation interference, converts the current information into a signal easily recognizable by the power measurement chip 4, and improves the stability and accuracy of the measurement.

[0055] This embodiment does not limit the specific structure of the differential amplifier circuit. It should be understood that the structure of the differential amplifier circuit should be determined based on the model of the power measurement chip 4. In a specific implementation, please refer to... Figure 6 The power measurement chip 4 is model BL0942. Its corresponding differential amplifier circuit includes a first resistor 51, a first capacitor 52, a second capacitor 53, and a second resistor 54 connected in sequence. The end of the first resistor 51 furthest from the first capacitor 52 is connected to the first end of the branch containing the relay contacts. The end of the first resistor 51 closest to the first capacitor 52 is connected to the power measurement chip 4. The end of the second resistor 54 furthest from the second capacitor 53 is connected to the second end of the branch containing the relay contacts. The end of the second resistor 54 closest to the second capacitor 53 is connected to the power measurement chip 4. The end of the first capacitor 52 connected to the second capacitor 53 is grounded. This differential amplifier circuit converts the current signal of the measured resistor into a voltage signal, facilitating reading and identification by the power measurement chip 4.

[0056] To facilitate users in obtaining the measurement range and power measurement structure, the power acquisition circuit of this utility model also includes a display module. The display module is connected to the control module 1 and is used to display the current range of the power acquisition circuit and the electrical energy parameters (voltage, current, and power, etc.) of the load appliance. This embodiment does not limit the selection of the display module; the display module can be an audio-visual component (indicator light, buzzer), an LED screen, or a touch screen, etc.

[0057] Embodiments of this utility model also provide a power meter, including an adjustable-range power acquisition circuit as described in any of the above embodiments. In some specific embodiments, the power meter is a socket-type power meter.

[0058] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An adjustable-range power acquisition circuit, characterized in that, The power acquisition circuit includes: a control module, a range switching module, and an energy measurement module. The range switching module includes an analog switch and a multi-contact relay. The input terminal of the analog switch is connected to the control module, and the output terminal of the analog switch is connected to the coil of the multi-contact relay. The normally closed contact of the multi-contact relay is connected to the first end of a first sampling resistor, and the second end of the first sampling resistor is grounded. The normally open contact of the multi-contact relay is connected to the first end of a second sampling resistor, and the second end of the second sampling resistor is grounded. The moving contact of the multi-contact relay is connected to the load appliance. The power measurement module includes a current acquisition circuit, a voltage acquisition circuit, and a power measurement chip. One end of the voltage acquisition circuit is connected to the load appliance, and the other end of the voltage acquisition circuit is connected to the power measurement chip. One end of the current acquisition circuit is connected to the moving contact of the multi-contact relay, and the other end of the current acquisition circuit is connected to the power measurement chip.

2. The adjustable range power acquisition circuit according to claim 1, characterized in that, The power acquisition circuit also includes a differential analog-to-digital converter (ADC). The first input terminal of the differential ADC is connected to the moving contact of the multi-contact relay. The second input terminal of the differential ADC is connected to the second terminal of the first sampling resistor and the second terminal of the second sampling resistor, respectively. The input terminal of the differential ADC is connected to the control module.

3. The adjustable range power acquisition circuit according to claim 2, characterized in that, The control module includes a microcontroller, which integrates the differential analog-to-digital converter.

4. The adjustable range power acquisition circuit according to claim 1, characterized in that, The power acquisition circuit also includes a voltage detection module. The input terminal of the voltage detection module is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively, and the output terminal of the voltage detection module is connected to the control module.

5. The adjustable range power acquisition circuit according to claim 4, characterized in that, The voltage detection module includes a first voltage comparator and a second voltage comparator. The first input terminal of the first voltage comparator is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively; the second input terminal of the first voltage comparator is connected to the first voltage signal source; and the output terminal of the first voltage comparator is connected to the control module. The first input terminal of the second voltage comparator is connected to the normally closed contact and the normally open contact of the multi-contact relay, respectively. The second input terminal of the second voltage comparator is connected to the second voltage signal source, and the output terminal of the second voltage comparator is connected to the control module.

6. The adjustable range power acquisition circuit according to claim 5, characterized in that, The power acquisition circuit also includes a power supply module. The input terminal of the power supply module is connected to an AC power source, and the output terminal of the power supply module is connected to the control module, the range switching module, the voltage detection module, and the energy measurement module, respectively.

7. The adjustable range power acquisition circuit according to claim 6, characterized in that, The power module also includes multiple output ports, the output voltage of which is adjustable. The second input terminal of the first voltage comparator and the second input terminal of the second voltage comparator are respectively connected to two output ports of the power module.

8. The adjustable range power acquisition circuit according to claim 1, characterized in that, The current acquisition circuit includes a differential amplifier circuit, which includes a first resistor, a first capacitor, a second capacitor, and a second resistor connected in sequence. The end of the first resistor furthest from the first capacitor is connected to the first end of the branch where the relay contacts are located. The end of the first resistor closest to the first capacitor is connected to the power measurement chip. The end of the second resistor furthest from the second capacitor is connected to the second end of the branch where the relay contacts are located. The end of the second resistor closest to the second capacitor is connected to the power measurement chip. The end of the first capacitor connected to the second capacitor is grounded.

9. The adjustable range power acquisition circuit according to claim 1, characterized in that, The power acquisition circuit also includes a display module, which is connected to the control module. The display module is used to display the current range of the power acquisition circuit and the power parameters of the load appliance.

10. A power meter, characterized in that, The power acquisition circuit includes an adjustable range according to any one of claims 1-9.

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