Power acquisition circuit with adjustable measuring range and power meter

Abstract

The utility model relates to a range-adjustable power acquisition circuit and a power meter, the power acquisition circuit comprises a control module, a switch module, an isolation module and an electric energy measurement module, and the control module is respectively connected with the switch module and the electric energy measurement module; the switch module comprises at least two Darlington tubes, the isolation module comprises at least two relays, the input ends of the Darlington tubes are connected with the control module, the output ends of the Darlington tubes are connected into branches where coils of the relays are located, and measuring resistors are arranged on branches where contacts of the relays are located and used for being connected with load electric appliances. The branches where the contacts of the at least two relays are located are connected in parallel; the electric energy measurement module comprises an electric energy measurement chip, a current acquisition circuit and a voltage acquisition circuit. The current acquisition circuit and the voltage acquisition circuit are both connected with a load electric appliance. According to the utility model, the Darlington tube is matched with the relay to realize range switching, the response of the Darlington tube is fast, and the efficient and stable range switching can be ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of electric energy detection, especially to a power collection circuit and power meter of adjustable range. BACKGROUND

[0002] At present, the range of power collection circuit is generally fixed, in order to ensure the accuracy of power measurement, the range of power collection circuit is generally not large enough, which leads to the need to design multiple power collection circuits with different range when facing different power range of electrical appliances, increasing the design and manufacturing cost; if the range is increased alone, it will also lead to insufficient accuracy of power collection circuit when measuring small power electrical appliances. Although there are power collection circuit schemes with multiple different ranges in related technologies, most of the circuit structures are complex and the manufacturing cost is high. SUMMARY

[0003] In order to solve at least one of the above technical problems, the utility model provides a power collection circuit and power meter of adjustable range.

[0004] According to some embodiments of the utility model, a power collection circuit with adjustable range is provided, which comprises a control module, a switch module, an isolation module and an electric energy measurement module, the control module is connected with the switch module and the electric energy measurement module respectively; the switch module comprises at least two darlington tubes, the isolation module comprises at least two relays, the darlington tube and the relay one by one, the input end of the darlington tube is connected with the control module, the output end of the darlington tube is connected with the branch of the coil of the relay, the branch of the contact of the relay is provided with a measuring resistor, the measuring resistor is used to be connected with the load electrical appliance, the branches of the contacts of the at least two relays are connected in parallel, and the resistance values of the measuring circuits on different relays are different; the electric energy measurement module comprises an electric energy measurement chip and a current collection circuit and a voltage collection circuit connected on the electric energy measurement chip, the current collection circuit is connected with the load electrical appliance, the voltage collection circuit is connected with the load electrical appliance, the current collection circuit is used to collect the current parameter of the load electrical appliance, and the voltage collection circuit is used to collect the voltage parameter of the load electrical appliance.

[0005] Based on the above scheme, the darlington tube cooperates with the relay to realize the switching of the measuring resistor connected with the electric energy measurement module, the darlington tube can be triggered based on the low-voltage control signal of the control module, the response is fast, the switching circuit structure of the measuring resistor is simple, and the high efficiency and stability of the power collection circuit when switching the range can be ensured.

[0006] In some possible implementation manners, the measuring resistor is connected in series with the load electrical appliance, and the current acquisition circuit includes a differential amplification circuit, and input ports of the differential amplification circuit are connected to two ends of the branch in which the contact of the relay is located.

[0007] Based on the above scheme, the current information of the electrical appliance is acquired based on the differential amplification circuit, the power fluctuation interference is reduced, the current information is converted into a signal convenient for the power measurement chip to recognize, and the stability and accuracy of measurement are improved.

[0008] In some possible implementation manners, the differential amplification circuit includes a first resistor, a first capacitor, a second capacitor and a second resistor connected in sequence, one end of the first resistor away from the first capacitor is connected to a first end of the branch in which the contact of the relay is located, one end of the first resistor close to the first capacitor is connected to the power measurement chip, one end of the second resistor away from the second capacitor is connected to a second end of the branch in which the contact of the relay is located, and one end of the second resistor close to the second capacitor is connected to the power measurement chip, and one end of the first capacitor connected to the second capacitor is grounded.

[0009] Based on the above scheme, the differential amplification circuit can convert the current signal into a voltage signal, and the power measurement chip can read and recognize conveniently.

[0010] In some possible implementation manners, the power acquisition circuit further includes a detection module, the detection module includes a differential pressure acquisition circuit and a voltage comparator, input ports of the differential pressure acquisition circuit are connected to two ends of the branch in which the contact of the relay is located, an output end of the differential pressure acquisition circuit is connected to a first input end of the voltage comparator, a second input end of the voltage comparator is connected to a voltage signal source, and an output end of the voltage comparator is connected to the control module, the differential pressure acquisition circuit is configured to acquire a potential difference between the two ends of the branch in which the contact of the relay is located and output a corresponding voltage signal, and the voltage comparator is configured to output a detection feedback signal when the output voltage of the differential pressure acquisition circuit is greater than the output voltage of the voltage signal source.

[0011] Based on the above scheme, by arranging the detection module, whether the current range is appropriate can be detected, when the potential difference between the two ends of the measuring resistor is greater than a preset voltage, it is determined that the current range is too small, the voltage comparator outputs the detection feedback signal, and the detection reminding effect is achieved.

[0012] In some possible implementation manners, the voltage signal source is a variable signal source, the variable signal source is connected to the control module, and the variable signal source is configured to generate a matching voltage signal based on the relay that is turned on.

[0013] Based on the above scheme, by setting the variable signal source, different voltage signals are output when different relays are turned on, which can improve the flexibility of range detection and realize the function of automatically adjusting the range.

[0014] In some possible implementation manners, the power acquisition circuit further comprises a key module, the key module is connected with the control module, and the control module is configured to send a switch control signal to the switch module in response to triggering of the key module, so that the corresponding relay is turned on.

[0015] Based on the above scheme, the range adjustment can be manually realized by triggering the key module, and the reliability of the power acquisition circuit control is enhanced.

[0016] In some possible implementation manners, the power acquisition circuit further comprises a power converter, the power converter is configured to be connected with an alternating current power supply and provide a direct current power supply for the control module, the switch module, the isolation module and the electric energy measurement module.

[0017] Based on the above scheme, the power converter is integrated into the power acquisition circuit, without the need of additionally setting a direct current power supply, and the modular design of the power acquisition circuit is facilitated.

[0018] In some possible implementation manners, the power acquisition circuit further comprises a display module, the display module is connected with the control module, and the display module is configured to display the current range of the power acquisition circuit and the electric energy parameters of the load appliance.

[0019] Based on the above scheme, by setting the display module, the range information and test information are fed back, and the use experience is facilitated to be enhanced.

[0020] In some possible implementation manners, at most one of the relays is turned on.

[0021] Based on the above scheme, the number of relays turned on at most one at a time can avoid coupling interference between the relays, the number of measured resistors corresponds to the number of range ranges, and the difficulty of selection of circuit devices is also reduced.

[0022] According to some other embodiments of the utility model, a power meter is provided, which comprises the adjustable range power acquisition circuit according to any one of the above embodiments.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, but not limiting the utility model.

[0024] Other features and aspects of the utility model will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art and the advantages, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present specification, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 A structural block diagram of the adjustable-range power collection circuit according to the embodiment of the present application is shown;

[0027] Figure 2 A circuit structural diagram of the adjustable-range power collection circuit according to the embodiment of the present application is shown;

[0028] Figure 3 A circuit structural diagram of the differential amplification circuit according to the embodiment of the present application is shown;

[0029] Figure 4 Another circuit structural diagram of the adjustable-range power collection circuit according to the embodiment of the present application is shown;

[0030] Figure 5 Another structural block diagram of the adjustable-range power collection circuit according to the embodiment of the present application is shown.

[0031] In the drawings,

[0032] 1, control module; 2, switch module; 3, isolation module; 4, electric energy measurement module; 41, current collection circuit; 411, first resistor; 412, first capacitor; 413, second capacitor; 414, second resistor; 42, voltage collection circuit; 5, detection module; 51, differential voltage collection circuit; 52, voltage comparator; 53, voltage signal source; 6, power converter. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present specification will be described clearly and completely in combination with the drawings in the embodiments of the present specification. Obviously, the described embodiments are only some embodiments of the present specification, not all embodiments. Based on the embodiments in the present specification, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0034] It is to be understood that the terminology "first", "second", etc. used in the specification and claims of the application and the above summary is merely used to differentiate between similar objects and does not necessarily imply a particular order or chronology. It is to be understood that data so used can be interchanged, where appropriate, so that the embodiments of the application described herein can be carried out in other than the order described. Furthermore, the terms "comprising" and "including" and any variations thereof are intended to cover a non-exclusive inclusion, such that processes, methods, systems, articles, or apparatuses that comprise, include, have or are otherwise accompanied by a feature are not necessarily limited to those features that are recited.

[0035] Various exemplary embodiments, features, and aspects of the present application will be described herein in detail with reference to the drawings. Like reference numerals in the drawings indicate like elements or features. Although various aspects of embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically noted.

[0036] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0037] The term "and / or" used in this text merely describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can represent three cases of existence of A alone, existence of A and B, and existence of B alone. In addition, the term "at least one" in this text means any one of a plurality or any combination of at least two of a plurality, 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.

[0038] In addition, in order to better illustrate the present application, a large number of specific details are given in the specific embodiments below. Those skilled in the art should understand that the present application can also be implemented without certain specific details. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail, in order to highlight the main idea of the present application.

[0039] Reference will now be made to Figures 1-2The utility model embodiment provides a kind of power acquisition circuit of adjustable range, which comprises: control module 1, switch module 2, isolation module 3 and electric energy measurement module 4, control module 1 is connected with switch module 2 and electric energy measurement module 4 respectively, switch module 2 is connected with isolation module 3, isolation module 3 is provided with multiple measuring resistors, control module 1 switches the measuring resistor of electric energy measurement module 4 by switch module 2 to control isolation module 3, to realize the purpose of switching range.

[0040] Specifically, please refer to Figure 2 , switch module 2 includes at least two Darlington tubes, isolation module 3 includes at least two relays, the Darlington tube and the relay one-to-one correspondence, the input end of Darlington tube is connected with control module 1, the output end of Darlington tube is connected with the branch of the coil of relay, the branch of the contact of relay is provided with measuring resistor, measuring resistor is used to be connected with load appliance, the branch of the contact of above-mentioned at least two relays is connected in parallel;Electric energy measurement module 4 includes electric energy measurement chip 43 and current acquisition circuit 41 and voltage acquisition circuit 42 connected on electric energy measurement chip 43, current acquisition circuit 41 is connected with load appliance, voltage acquisition circuit 42 is connected with load appliance, current acquisition circuit 41 is used to acquire the current parameter of load appliance, and voltage acquisition circuit 42 is used to acquire the voltage parameter of load appliance.

[0041] Based on the above circuit structure, control module 1 sends high-level signal to the input end of the specified Darlington tube in switch module 2, and the output end outputs high-level signal, the coil branch of the corresponding relay is energized, so that the contact is closed, the contact branch is connected to the electric energy measurement module 4, that is, the measuring resistor of the contact branch is connected to the electric energy measurement module 4, and by sending control signals to different Darlington tubes, different measuring resistors connected to the electric energy measurement module 4 can be controlled.

[0042] In the utility model, the resistance values of the measuring resistors on different relays can be the same or different.

[0043] In some possible embodiments, the resistance values of the measuring resistors on all relays are completely consistent, and the number of measuring resistors connected to the electric energy measurement module 4 is controlled by controlling the number of conducting Darlington tubes. Since the measuring resistors are connected in parallel, the total resistance value is different when the number of parallel measuring resistors is different, so the range control switching can be realized.

[0044] In some possible embodiments, the resistances of the measurement resistors on different relays are different, and one relay can be turned on at a time or multiple relays can be turned on at a time when the range control switching is performed. Since the resistances of the measurement resistors are different, the resistance of the parallel connection of different measurement resistors is also different from the original resistance. That is, a small number of measurement resistors can be used to switch multiple different ranges. For example, when there are three different measurement resistors, only one relay can be turned on at a time, in which case there are three different ranges. Two relays can be turned on at the same time, in which case three different ranges are added. Or three relays are turned on at the same time, in which case a new range is added. That is, the three different measurement resistors can correspond to at most seven different ranges, which can greatly increase the number of range ranges and improve the flexibility of range switching.

[0045] Based on the above structure, in further embodiments, at most one relay is turned on when the range control switching is performed, that is, only one measurement resistor is connected at a time. Based on this setting, the branch where the contact of the single relay is connected to the power measurement module 4, which can avoid the coupling interference between the relays, and the number of measurement resistors corresponds to the number of range ranges. Moreover, the processing and calculation configuration of the parallel connection of the measurement resistors do not need to be considered, which can reduce the difficulty of circuit design.

[0046] The specific structure of the current acquisition circuit 41 and the voltage acquisition circuit 42 is not limited in the embodiment. For example, the current acquisition circuit 41 can be a detection circuit based on a shunt or a detection circuit based on a coil current transformer. The voltage acquisition circuit 42 can be a detection circuit based on a voltage division resistor principle, a detection circuit based on a Hall sensor, or a detection circuit based on a capacitive coupling sensor, etc. In addition, the specific signal of the power measurement chip 43 is not limited in the embodiment. The power measurement chip 43 can be BL0942, AD71056, HLW8032, or other types of chips.

[0047] In some embodiments, please refer to Figure 2 The measurement resistor is connected in series with the load appliance, and the current acquisition circuit 41 includes a differential amplification circuit, and the input ports of the differential amplification circuit are connected to the two ends of the branch where the contact is located. Based on the above structure, since the measurement resistor is connected in series with the load appliance, the measurement resistor and the load appliance share the current and divide the voltage, and the current value of the measurement resistor is the current value of the load appliance. By connecting the differential amplification circuit to the two ends of the measurement resistor (i.e., the two ends of the branch where the contact is located), the current parameter of the load appliance can be obtained. The reason for setting the differential amplification circuit in the embodiment is that the differential amplification circuit can be used to collect the current information of the appliance, which can reduce the interference of power fluctuations, convert the current information into a signal that is easy for the power measurement chip 43 to recognize, and improve the stability and accuracy of measurement.

[0048] The embodiment is not limited to the specific structure of the differential amplification circuit, and it should be understood that the structure of the differential amplification circuit should be determined according to the model of the electric energy measurement chip 43. In a specific embodiment, please refer to Figure 3 , the model of the electric energy measurement chip 43 is BL0942, and the corresponding differential amplification circuit includes a first resistor 411, a first capacitor 412, a second capacitor 413, and a second resistor 414 connected in sequence. One end of the first resistor 411 away from the first capacitor 412 is connected to the first end of the branch where the contact of the relay is located, and the other end of the first resistor 411 close to the first capacitor 412 is connected to the electric energy measurement chip 43. One end of the second resistor 414 away from the second capacitor 413 is connected to the second end of the branch where the contact of the relay is located, and the other end of the second resistor 414 close to the second capacitor 413 is connected to the electric energy measurement chip 43. One end of the first capacitor 412 connected to the second capacitor 413 is grounded. Through the differential amplification circuit with the above structure, the current signal of the measurement resistor can be converted into a voltage signal, thereby facilitating the electric energy measurement chip 43 to read and identify.

[0049] In some embodiments, please refer to Figure 4 , the power collection circuit further includes a detection module 5, which includes a differential pressure collection circuit 51 and a voltage comparator 52. The input port of the differential pressure collection circuit 51 is connected to the two ends of the branch where the contact of the relay is located. The output of the differential pressure collection circuit 51 is connected to the first input of the voltage comparator 52. The second input of the voltage comparator 52 is connected to a voltage signal source 53. The output of the voltage comparator 52 is connected to the control module 1. The differential pressure collection circuit 51 is used to obtain the potential difference between the two ends of the branch where the contact of the relay is located and output the corresponding voltage signal. The voltage comparator 52 is used to output a detection feedback signal when the output voltage of the differential pressure collection circuit 51 is greater than the output voltage of the voltage signal source 53. The embodiment can be applied to the power measurement of household appliances. The purpose of setting the detection module 5 is to detect whether the current range is appropriate. Specifically, the range is determined by the current parameter. Since the voltage standard of household appliances is standard voltage, the power size is positively correlated with the current size. For the same measurement resistor, the larger the current value of the load appliance, the larger the voltage difference between the two ends of the measurement resistor. When the voltage difference between the two ends of the measurement resistor is greater than the output voltage of the voltage signal source 53, the voltage signal output by the differential amplification circuit may exceed the working voltage range of the electric energy measurement chip 43, which may cause inaccurate measurement and damage to the chip. Therefore, the voltmeter is set to output a detection feedback signal at this time to prompt a warning.

[0050] Further, based on the power acquisition circuit, the automatic switching range function can be realized. Specifically, the voltage signal source 53 is a variable signal source, the variable signal source is connected with the control module 1, and the variable signal source is used for generating a matching voltage signal based on the turned-on relay. The automatic switching range process of the power acquisition circuit includes that the control module 1 controls one relay to be turned on through the switch module 2, so that the corresponding measurement resistor is connected to the electric energy measurement module 4, the voltage signal source 53 generates a matching voltage signal according to the turned-on relay, the measurement resistor, the range and the voltage signal correspond to each other, when the range is insufficient, the voltage comparator 52 in the measurement module outputs a detection feedback signal, and the control module 1 cuts off the current relay and turns on another relay after receiving the detection feedback signal, and the above-mentioned actions are repeatedly performed until the range matches the actual power of the load appliance.

[0051] In some embodiments, the power acquisition circuit further includes a button module, the button module is connected with the control module 1, and the control module 1 is used for sending a switch control signal to the switch module 2 according to the triggering of the button module, so that the corresponding relay is turned on. Based on the button module, the manual control switching range can be realized. In some possible cases, the user knows the power range of the load appliance, and can directly manually switch the range through the button module, so that the measurement efficiency is improved. In other possible cases, although the detection module 5 automatically switches when the power of the load appliance is greater than the range, the range is far greater than the power of the load appliance, and the feedback cannot be obtained, at this time, the user can manually switch the range through the button module, so that the accurate power measurement result is obtained.

[0052] In order to facilitate the user to obtain the range and the power measurement structure, the power acquisition circuit further includes a display module, the display module is connected with the control module 1, and the display module is used for displaying the current range of the power acquisition circuit and the electric energy parameters (voltage, current and power) of the load appliance. The selection of the display module is not limited in the embodiment, the display module can be an audible and visual component (indicator light, buzzer), an LED screen or a touch screen.

[0053] In the utility model, the power acquisition circuit needs to be provided with a direct current power supply, the direct current power supply can supply power to the control module 1, the electric energy measurement chip 43, the darlington tube and the relay, and the load appliance is connected with an alternating current power supply, in order to further simplify the circuit structure, in some embodiments, please refer to Figure 5 , the power acquisition circuit further includes a power converter 6, the power converter 6 is used for connecting the alternating current power supply and providing the direct current power supply to the control module 1, the switch module 2, the isolation module 3 and the electric energy measurement module 4. Based on the power converter 6, the power acquisition circuit can be modularly arranged, specifically, a two-port circuit can be designed, one end is used for connecting the alternating current power supply, and the other end is used for connecting the load appliance.

[0054] Embodiments of the utility model further provide a power meter, including the adjustable range power acquisition circuit of any one of the above-embodiment. In some specific implementation, the power meter is socket type power meter.

[0055] The above has described each embodiment of the utility model, the above-mentioned explanation is exemplary, is not exhaustive, and also is not limited to each disclosed embodiment. Many modifications and changes are obvious to those of ordinary skill in the art without deviating from the scope and spirit of the described embodiments. The selection of the terms used in this paper aims to best explain the principles, practical applications or technical improvements in the market of each embodiment, or enable other ordinary skilled in the art to understand each embodiment disclosed in this paper.

Claims

1. A range adjustable power harvesting circuit, characterized by, The power collection circuit comprises a control module, a switch module, an isolation module and an electric energy measurement module, the control module is connected with the switch module and the electric energy measurement module respectively; The switch module comprises at least two Darlington tubes, the isolation module comprises at least two relays, the Darlington tubes correspond to the relays one by one, the input end of the Darlington tube is connected with the control module, the output end of the Darlington tube is connected with the branch of the coil of the relay, the branch of the contact of the relay is provided with a measurement resistance, the measurement resistance is used for being connected with the load electric appliance, the branches of the contacts of the at least two relays are connected in parallel, and the resistance values of the measurement resistances on the different relays are different; The electric energy measurement module comprises an electric energy measurement chip, a current collection circuit and a voltage collection circuit connected with the electric energy measurement chip, the current collection circuit is connected with the load electric appliance, the voltage collection circuit is connected with the load electric appliance, the current collection circuit is used for collecting the current parameter of the load electric appliance, and the voltage collection circuit is used for collecting the voltage parameter of the load electric appliance.

2. The adjustable range power harvesting circuit of claim 1, wherein, The measurement resistance is connected with the load electric appliance in series, the current collection circuit comprises a differential amplification circuit, and the input ports of the differential amplification circuit are connected at two ends of the branch of the contact of the relay.

3. A range adjustable power harvesting circuit according to claim 2, wherein, The differential amplification circuit comprises a first resistance, a first capacitor, a second capacitor and a second resistance connected in sequence, one end of the first resistance away from the first capacitor is connected with the first end of the branch of the contact of the relay, one end of the first resistance close to the first capacitor is connected to the electric energy measurement chip, one end of the second resistance away from the second capacitor is connected with the second end of the branch of the contact of the relay, one end of the second resistance close to the second capacitor is connected to the electric energy measurement chip, and one end of the first capacitor connected with the second capacitor is grounded.

4. The adjustable range power harvesting circuit of claim 2, wherein, The power collection circuit further comprises a detection module, the detection module comprises a differential pressure collection circuit and a voltage comparator, the input ports of the differential pressure collection circuit are connected at two ends of the branch of the contact of the relay, the output end of the differential pressure collection circuit is connected with the first input end of the voltage comparator, the second input end of the voltage comparator is connected with a voltage signal source, the output end of the voltage comparator is connected with the control module, the differential pressure collection circuit is used for acquiring the potential difference of the two ends of the branch of the contact of the relay and outputting a corresponding voltage signal, and the voltage comparator is used for outputting a detection feedback signal when the output voltage of the differential pressure collection circuit is greater than the output voltage of the voltage signal source.

5. A range adjustable power harvesting circuit according to claim 4, wherein, The voltage signal source is a variable signal source, the variable signal source is connected with the control module, and the variable signal source is used for generating a matching voltage signal based on the conduction of the relay.

6. The adjustable range power harvesting circuit of claim 1, wherein, The power collection circuit further comprises a key module, the key module is connected with the control module, and the control module is used for sending a switch control signal to the switch module in response to the triggering of the key module, so that the corresponding relay is turned on.

7. The adjustable range power harvesting circuit of claim 1, wherein, The power acquisition circuit further comprises a power converter, which is used for connecting an alternating current power supply and providing a direct current power supply for the control module, the switch module, the isolation module and the electric energy measurement module.

8. The adjustable range power harvesting circuit of claim 1, wherein, The power acquisition circuit further comprises a display module, which is connected with the control module and used for displaying a current range of the power acquisition circuit and an electric energy parameter of the load electric appliance.

9. The adjustable range power harvesting circuit of claim 1, wherein, At most one of the relays is on.

10. A power meter, characterized by A power acquisition circuit with adjustable range comprising any one of claims 1-9.

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