Sampling circuits and electronic equipment

Abstract

An embodiment of the present invention relates to a sampling circuit and electronic device. The sampling circuit includes: a sampling isolation module, a calculation module, a comparison module, and a control module. The sampling isolation module has an input connected to an output of the sampling circuit, a first output connected to a first input of the comparison module, a second output connected to a first input of the calculation module, and a third output connected to a second input of the calculation module. The calculation module has an output connected to a second input of the comparison module. The comparison module has a first output connected to one end of the control module, and a second output connected to the other end of the control module. This allows the sampling of a two-phase circuit to complete three-phase sampling processing, improving sampling accuracy and the utilization rate of the controller's IO ports.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of motor drive technology, and in particular to a sampling circuit and electronic equipment. Background Art

[0002] During the normal operation of the compressor, its essence is the operation process of the motor. The control of the compressor is mainly the control of the motor. The motor control system can control the start, acceleration, deceleration and stop of the motor. In order to make the motor respond quickly to the corresponding control, a sampling circuit is usually set in the motor control system. The sampling circuit can sample the current during the operation of the motor and control the motor according to the sampled current.

[0003] Traditional current sampling directly samples one, two, or three of the three phases (U, V, and W). Single-phase sampling is used for low-precision control, while two and three-phase sampling are primarily used for higher-precision control. Current sampling of all three motor phases improves control accuracy and efficiency. However, using the same sampling circuit for all three phases imposes strict requirements on the PCB layout and reduces the utilization of the microcontroller's IO ports. Summary of the Invention

[0004] In view of this, in order to solve the above-mentioned technical problems of low sampling accuracy and low utilization rate of the serial port of the controller, an embodiment of the present invention provides a sampling circuit and an electronic device.

[0005] In a first aspect, an embodiment of the present invention provides a sampling circuit, comprising:

[0006] Sampling isolation module, calculation module, comparison module and control module;

[0007] The input end of the sampling isolation module is connected to the output end of the sampling circuit, the first output end is connected to the first input end of the comparison module, the second output end is connected to the first input end of the calculation module, and the third output end is connected to the second input end of the calculation module;

[0008] The output terminal of the calculation module is connected to the second input terminal of the comparison module;

[0009] The first output terminal of the comparison module is connected to one terminal of the control module, and the second output terminal is connected to the other terminal of the control module.

[0010] In one possible implementation, the sampling and isolation module includes: a sampling and filtering submodule and an isolation submodule;

[0011] The output terminals of the sampling and filtering submodule are sequentially connected to the input terminals of the isolation submodule;

[0012] The first output terminal of the isolation submodule is connected to the second output terminal and the first node, the first node is connected to the first input terminal of the comparison module and the first input terminal of the calculation module, and the third output terminal is connected to the second input terminal of the calculation module.

[0013] In a possible implementation, the sampling and filtering submodule includes: a first sampling and filtering unit and a second sampling and filtering unit;

[0014] The first output end of the first sampling and filtering unit is connected to the first input end of the isolation submodule, and the second output end is connected to the second input end of the isolation submodule;

[0015] The first output terminal of the second sampling and filtering unit is connected to the third input terminal of the isolation submodule, and the second output terminal of the second sampling and filtering unit is connected to the fourth input terminal of the isolation submodule.

[0016] In a possible implementation, the first sampling and filtering unit includes: a first impedance element, a second impedance element, and a first capacitive reactance element;

[0017] One end of the first impedance element is connected to one end of the second impedance element and the input end of the first phase sampling circuit, and the other end is connected to the second input end of the isolation submodule and the first ground end;

[0018] The other end of the second impedance element is connected to one end of the first capacitive reactance element and the first input end of the isolation submodule;

[0019] The other end of the first capacitive reactance element is connected to the second ground end.

[0020] In a possible implementation, the second sampling and filtering unit includes: a third impedance element, a fourth impedance element, and a second capacitive reactance element;

[0021] One end of the third impedance element is connected to one end of the fourth impedance element and the input end of the second phase sampling circuit, and the other end is connected to the fourth input end of the isolation submodule and the third ground end;

[0022] The other end of the fourth impedance element is connected to one end of the second capacitive reactance element and the third input end of the isolation submodule;

[0023] The other end of the second capacitive reactance element is connected to the fourth ground end.

[0024] In one possible implementation, the isolation submodule includes: a first isolation unit, a second isolation unit, and a third isolation unit;

[0025] The first input terminal of the first isolation unit is connected to the first output terminal of the sampling and filtering submodule, the second input terminal is connected to the second output terminal of the sampling and filtering submodule, and the output terminal is connected to a first node, and the first node is connected to the first input terminal of the comparison module and the first input terminal of the calculation module;

[0026] The first input terminal of the second isolation unit is connected to the third output terminal of the sampling and filtering submodule, the second input terminal is connected to the fourth output terminal of the sampling and filtering submodule, and the output terminal is connected to the first node;

[0027] The input end of the third isolation unit is connected to the power supply voltage output end, and the output end is connected to the second input end of the calculation module.

[0028] In a possible implementation manner, the first isolation unit includes: a first isolator and a fifth impedance element;

[0029] The non-inverting input terminal of the first isolator is connected to the first output terminal of the sampling and filtering submodule, the reverse input terminal is connected to the second output terminal of the sampling and filtering submodule and the output terminal of the first isolator, and the output terminal is connected to one end of the fifth impedance element;

[0030] The other end of the fifth impedance element is connected to the first node.

[0031] In a possible implementation manner, the second isolation unit includes: a second isolator and a sixth impedance element;

[0032] The non-inverting input terminal of the second isolator is connected to the third output terminal of the sampling and filtering submodule, the reverse input terminal is connected to the fourth output terminal of the sampling and filtering submodule and the output terminal of the second isolator, and the output terminal is connected to one end of the sixth impedance element;

[0033] The other end of the sixth impedance element is connected to the first node.

[0034] In a possible implementation, the third isolation unit includes: a seventh impedance element, an eighth impedance element, and a third isolator;

[0035] One end of the seventh impedance element is connected to the output end of the power supply voltage, and the other end is connected to one end of the eighth impedance element and the non-inverting input end of the third isolator;

[0036] The other end of the eighth impedance element is connected to the fifth ground terminal;

[0037] The inverting input terminal of the third isolator is connected to the output terminal of the third isolator, and the output terminal is connected to the second input terminal of the calculation module.

[0038] In one possible implementation, the calculation module includes:

[0039] a ninth impedance element, a tenth impedance element, an eleventh impedance element, a twelfth impedance element, and a calculator;

[0040] One end of the ninth impedance element is connected to the first node, and the other end is connected to one end of the eleventh impedance element and the inverting input terminal of the calculator;

[0041] The other end of the eleventh impedance element is connected to the output end of the calculator and the second input end of the comparison module;

[0042] One end of the tenth impedance element is connected to the third output end of the isolation submodule, and the other end is connected to one end of the twelfth impedance element and the same-direction input end of the calculator;

[0043] The other end of the twelfth impedance element is connected to the sixth ground end.

[0044] In one possible implementation, the comparison module includes:

[0045] a thirteenth impedance element, a fourteenth impedance element, a first comparator, a fifteenth impedance element, a sixteenth impedance element, a seventeenth impedance element, and a second comparator;

[0046] One end of the thirteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the fourteenth impedance element and the non-inverting input end of the first comparator;

[0047] The other end of the fourteenth impedance element is connected to the seventh ground terminal;

[0048] The inverting input terminal of the first comparator is connected to the first node, and the output terminal is connected to the first input terminal of the control module;

[0049] One end of the fifteenth impedance element is connected to the output end of the calculation module, and the other end is connected to the inverting input end of the second comparator;

[0050] One end of the sixteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the seventeenth impedance element and the non-inverting input end of the second comparator;

[0051] The other end of the seventeenth impedance element is connected to the eighth ground terminal;

[0052] An output terminal of the second comparator is connected to a second input terminal of the control module.

[0053] In one possible implementation, the sampling isolation module obtains a sampling current signal when determining the sampling current of the two-phase circuit, and isolates an initial sampling voltage signal corresponding to the sampling current signal to obtain a stable sampling voltage signal;

[0054] The calculation module receives the stable voltage signal output by the sampled current of the two-phase circuit and the reference voltage provided by the third-phase voltage, and outputs the equivalent sampled voltage signal of the third-phase circuit through calculation processing;

[0055] The comparison module compares the sampled voltage signal output by the sampling isolation module with the reference voltage signal and provides a control signal to the control module; and compares the equivalent sampled voltage signal output by the calculation module with the reference voltage signal and provides another control signal to the control module; the control module controls the peripheral circuit accordingly after receiving the control signal.

[0056] In a second aspect, an embodiment of the present invention provides an electronic device, comprising the sampling circuit as described in any one of the first aspects.

[0057] The sampling scheme provided by the embodiment of the present invention comprises a sampling isolation module, a calculation module, a comparison module and a control module; the input end of the sampling isolation module is connected to the output end of the sampling circuit, the first output end is connected to the first input end of the comparison module, the second output end is connected to the first input end of the calculation module, and the third output end is connected to the second input end of the calculation module; the output end of the calculation module is connected to the second input end of the comparison module; the first output end of the comparison module is connected to one end of the control module, and the second output end is connected to the other end of the control module. The sampling isolation module is connected to the calculation module, and the current signal sampled by the two-phase circuit is processed and the output signal is used as the input end of the calculation module for calculation to obtain a third-phase equivalent sampling signal. The calculated third-phase equivalent sampling signal and the two signals obtained by the sampling isolation module are used as input signals of the comparison module, respectively compared with the reference signal, and output as two-phase control signals to the control module, so that the control module controls the circuit according to the different signals received. This scheme can achieve the purpose of sampling the two-phase circuit to complete the three-phase circuit sampling processing, and improve the sampling accuracy and the utilization rate of the controller's IO port. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0059] Figure 1 A schematic structural diagram of a sampling circuit provided by an embodiment of the present invention;

[0060] Figure 2 A schematic structural diagram of another sampling circuit provided by an embodiment of the present invention;

[0061] Figure 3 This is a schematic structural diagram of another sampling circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0063] In the embodiments of the present invention, the terms "including" and "having" are intended to convey an open-ended, inclusive meaning and indicate that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first" and "second," etc., are used merely as labels and do not limit the quantity of their objects. Furthermore, the various elements and regions in the drawings are shown for schematic purposes only, and thus the present invention is not limited to the sizes or distances shown in the drawings.

[0064] To facilitate understanding of the embodiments of the present invention, specific embodiments will be further explained below with reference to the accompanying drawings. The embodiments do not limit the embodiments of the present invention.

[0065] A sampling circuit has an analog signal input, a control signal input, and an analog signal output. It receives an input voltage at a specified instant and maintains that voltage at the output until the next sampling cycle begins. Sampling operates in one of two states: sample and hold. In the sample state, the switch is on, tracking the analog input signal's level changes as quickly as possible until the hold signal is received. In the hold state, the switch is off, stopping the tracking process and maintaining the instantaneous value of the input signal before the switch is turned off.

[0066] Figure 1 Schematic diagram of a sampling circuit provided by an embodiment of the present invention. The sampling circuit can be applied to a sampling device. Figure 1 The structure shown in FIG. 1 is a sampling circuit that specifically includes:

[0067] Sampling and isolation module 11, calculation module 12, comparison module 13 and control module 14;

[0068] Among them, an internal circuit structure of a sampling circuit provided by an embodiment of the present invention includes:

[0069] The input end of the sampling isolation module 11 is connected to the output end of the sampling circuit, the first output end is connected to the first input end of the comparison module 13, the second output end is connected to the first input end of the calculation module 12, and the third output end is connected to the second input end of the calculation module 12;

[0070] The output terminal of the calculation module 12 is connected to the second input terminal of the comparison module 13;

[0071] A first output terminal of the comparison module 13 is connected to one terminal of the control module 14 , and a second output terminal of the comparison module 13 is connected to the other terminal of the control module 14 .

[0072] according to Figure 1 In the diagram provided, the sampling and isolation module inputs the randomly collected voltage signals corresponding to the two-phase circuit into the calculation module 12 for calculation processing, obtaining a third-phase equivalent voltage signal. After comparing it with the reference voltage in the comparison module 13, the compared voltage signal is output to the control module 14. The control module 14 controls the external circuit based on the input voltage signal. At the same time, after selecting one of the two-phase voltage signals collected by the sampling and isolation module, it is compared with the reference voltage signal through the comparison module to obtain another voltage signal representing the sampled signal. This is input as an output signal to the control module 14, which controls the external circuit through the control module 14. This completes the control processing process of the three-phase signal by sampling the two-phase signal, improving the sampling accuracy and the utilization rate of the controller's IO port.

[0073] An embodiment of the present invention provides a sampling circuit, which is provided with a sampling isolation module, a calculation module, a comparison module and a control module. The input end of the sampling isolation module is connected to the output end of the sampling circuit, the first output end is connected to the first input end of the comparison module, the second output end is connected to the first input end of the calculation module, and the third output end is connected to the second input end of the calculation module; the output end of the calculation module is connected to the second input end of the comparison module; the first output end of the comparison module is connected to one end of the control module, and the second output end is connected to the other end of the control module. The sampling isolation module is connected to the calculation module, and the two-phase sampled current signals are processed to obtain the corresponding output voltage signals. The output signals are used as the input end of the calculation module for calculation to obtain the third-phase equivalent sampling signal. The calculated third-phase equivalent sampling signal and the two signals obtained by the sampling isolation module are used as input signals of the comparison module, respectively compared with the reference signal, and output as two-phase control signals to the control module, so that the control module controls the circuit according to the different signals received. This solution can achieve the purpose of completing three-phase sampling processing by sampling a two-phase circuit, improve sampling accuracy and the technical effect of improving the utilization rate of the controller's IO port.

[0074] In an optional solution of an embodiment of the present invention, the sampling isolation module includes: a sampling filtering submodule and an isolation submodule; each output end of the sampling filtering submodule is sequentially connected to each input end of the isolation submodule; the first output end of the isolation submodule is connected to the second output end and the first node, the first node is connected to the first input end of the comparison module and the first input end of the calculation module, and the third output end is connected to the second input end of the calculation module.

[0075] In an optional solution of the embodiment of the present invention, the sampling filtering submodule includes: a first sampling filtering unit and a second sampling filtering unit; the first output end of the first sampling filtering unit is connected to the first input end of the isolation submodule, and the second output end is connected to the second input end of the isolation submodule; the first output end of the second sampling filtering unit is connected to the third input end of the isolation submodule, and the second output end is connected to the fourth input end of the isolation submodule.

[0076] In an optional solution of an embodiment of the present invention, the first sampling and filtering unit includes: a first impedance element, a second impedance element, and a first capacitive reactance element; one end of the first impedance element is connected to one end of the second impedance element and the input end of the first phase sampling circuit, and the other end is connected to the second input end of the isolation submodule and the first ground end; the other end of the second impedance element is connected to one end of the first capacitive reactance element and the first input end of the isolation submodule; and the other end of the first capacitive reactance element is connected to the second ground end.

[0077] In an optional scheme of the embodiment of the present invention, the second sampling and filtering unit includes: a third impedance element, a fourth impedance element, and a second capacitive reactance element; one end of the third impedance element is connected to one end of the fourth impedance element and the input end of the second phase sampling circuit, and the other end is connected to the fourth input end of the isolation submodule and the third ground end; the other end of the fourth impedance element is connected to one end of the second capacitive reactance element and the third input end of the isolation submodule; and the other end of the second capacitive reactance element is connected to the fourth ground end.

[0078] In an optional solution of the embodiment of the present invention, the isolation submodule includes: a first isolation unit, a second isolation unit and a third isolation unit; the first input end of the first isolation unit is connected to the first output end of the sampling and filtering submodule, the second input end is connected to the second output end of the sampling and filtering submodule, and the output end is connected to a first node, and the first node is connected to the first input end of the comparison module and the first input end of the calculation module; the first input end of the second isolation unit is connected to the third output end of the sampling and filtering submodule, the second input end is connected to the fourth output end of the sampling and filtering submodule, and the output end is connected to the first node; the input end of the third isolation unit is connected to the power supply voltage output end, and the output end is connected to the second input end of the calculation module.

[0079] In an optional solution of the embodiment of the present invention, the first isolation unit includes: a first isolator and a fifth impedance element; the first isolator has a non-inverting input end connected to the first output end of the sampling and filtering submodule, an inverting input end connected to the second output end of the sampling and filtering submodule and the output end of the first isolator, and an output end connected to one end of the fifth impedance element; and the other end of the fifth impedance element is connected to the first node.

[0080] In an optional solution of the embodiment of the present invention, the second isolation unit includes: a second isolator and a sixth impedance element; the non-inverting input end of the second isolator is connected to the third output end of the sampling and filtering submodule, the reverse input end is connected to the fourth output end of the sampling and filtering submodule and the output end of the second isolator, and the output end is connected to one end of the sixth impedance element; the other end of the sixth impedance element is connected to the first node.

[0081] In an optional scheme of an embodiment of the present invention, the third isolation unit includes: a seventh impedance element, an eighth impedance element and a third isolator; one end of the seventh impedance element is connected to the output end of the power supply voltage, and the other end is connected to one end of the eighth impedance element and the same-direction input end of the third isolator; the other end of the eighth impedance element is connected to the fifth ground end; the inverting input end of the third isolator is connected to the output end of the third isolator, and the output end is connected to the second input end of the computing module.

[0082] In an optional scheme of the embodiment of the present invention, the calculation module includes: a ninth impedance element, a tenth impedance element, an eleventh impedance element, a twelfth impedance element and a calculator; one end of the ninth impedance element is connected to the first node, and the other end is connected to one end of the eleventh impedance element and the inverting input end of the calculator; the other end of the eleventh impedance element is connected to the output end of the calculator and the second input end of the comparison module; one end of the tenth impedance element is connected to the third output end of the isolation submodule, and the other end is connected to one end of the twelfth impedance element and the same-direction input end of the calculator; the other end of the twelfth impedance element is connected to the sixth ground end.

[0083] In an optional scheme of the embodiment of the present invention, the calculation module includes: a thirteenth impedance element, a fourteenth impedance element, a first comparator, a fifteenth impedance element, a sixteenth impedance element, a seventeenth impedance element and a second comparator; one end of the thirteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the fourteenth impedance element and the same-inverting input end of the first comparator; the other end of the fourteenth impedance element is connected to the seventh ground end; the inverting input end of the first comparator is connected to the first node, and the output end is connected to the first input end of the control module; one end of the fifteenth impedance element is connected to the output end of the calculation module, and the other end is connected to the inverting input end of the second comparator; one end of the sixteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the seventeenth impedance element and the same-inverting input end of the second comparator; the other end of the seventeenth impedance element is connected to the eighth ground end; and the output end of the second comparator is connected to the second input end of the control module.

[0084] In an optional solution of an embodiment of the present invention, the sampling isolation module obtains a sampling current signal when determining the sampling current of the two-phase circuit, and isolates the initial sampling voltage signal corresponding to the sampling current signal to obtain a stable sampling voltage signal; the calculation module receives the stable voltage signal output by the sampling current of the two-phase circuit and the reference voltage provided by the third-phase voltage, and outputs an equivalent sampling voltage signal of the third-phase circuit through calculation processing; the comparison module compares the sampling voltage signal output by the sampling isolation module with the reference voltage signal and provides a control signal to the control module; and the control module compares the equivalent sampling voltage signal output by the calculation module with the reference voltage signal and provides another control signal to the control module; the control module controls the peripheral circuit accordingly after receiving the control signal.

[0085] The following will be introduced as an example in which the sampling isolation module includes: a sampling filter submodule and an isolation submodule, the sampling filter submodule includes: a first sampling filter unit and a second sampling filter unit, and the isolation submodule includes: a first isolation unit, a second isolation unit and a third isolation unit. The resistor in the embodiment of the present invention represents a resistor device, which can be represented by a resistor but is not limited to a resistor device. Figure 2 , shows a schematic diagram of the structure of another sampling circuit provided by an embodiment of the present invention. This sampling circuit is described based on the first sampling circuit. Figure 2 The provided diagram shows that the sampling circuit specifically includes:

[0086] Sampling and isolation module 11 , calculation module 12 , comparison module 13 and control module (hereinafter collectively referred to as MCU) 14 .

[0087] Furthermore, the sampling circuit also includes a first node (hereinafter referred to as P1). The above node can be understood as a connection point formed by connecting two devices or three devices. For example, P1 is an electrical connection point formed by connecting the isolation module, the comparison module, and the calculation module.

[0088] Furthermore, the overcurrent protection circuit also includes a power supply voltage VCC for providing a reference voltage for the sampling circuit.

[0089] Furthermore, the sampling isolation module obtains a sampling current signal when the sampling current of the two-phase circuit is determined, and isolates an initial sampling voltage signal corresponding to the sampling current signal to obtain a stable sampling voltage signal.

[0090] Furthermore, the calculation module receives the stable voltage signal output by the sampled current of the two-phase circuit and the reference voltage provided by the third-phase voltage, and outputs the equivalent sampled voltage signal of the third-phase circuit through calculation processing.

[0091] Furthermore, the comparison module compares the sampled voltage signal output by the sampling isolation module with the reference voltage signal and provides a control signal to the control module; and compares the equivalent sampled voltage signal output by the calculation module with the reference voltage signal and provides another control signal to the control module.

[0092] Furthermore, the control module controls the peripheral circuit accordingly after receiving the control signal.

[0093] The sampling isolation module 11 specifically includes:

[0094] Sampling and filtering submodule 21 and isolation submodule 22.

[0095] The output terminals of the sampling and filtering submodule 21 are connected in sequence to the input terminals of the isolation submodule 22; the first output terminal of the isolation submodule 22 is connected to the second output terminal and the first node P1, the first node P1 is connected to the first input terminal of the comparison module 13 and the first input terminal of the calculation module 12, and the third output terminal is connected to the second input terminal of the calculation module 12.

[0096] according to Figure 2The provided diagram shows that when the circuit is operating normally, the sampling and filtering submodule 21 samples the current, processes it to obtain a sampled voltage, and isolates the sampled voltage output by the sampling and filtering submodule 21 from the original electrical signal through the isolation function of the isolation submodule 22, obtaining a complete voltage signal after sampling. The voltage signal and the reference voltage adjusted by the isolation submodule 22 are input into the calculation module 12. Kirchhoff's law of constant current is used to calculate the third-phase equivalent sampling signal by sampling the two-phase voltage signal. The third-phase equivalent sampling signal is then output to the comparison module 13 through the calculation module 12. The third-phase equivalent sampling signal is compared with the reference voltage signal, and the comparison output is input as a comparison signal to the control module MCU. The control module MCU analyzes the received comparison signal information and controls the peripheral circuits. At the same time, the isolation submodule 22 outputs the two-phase sampled voltage signal, and the two-phase voltage signal is used as the input signal of the comparison module, compared with the reference voltage signal, and the second output signal is input to the control module MCU. After receiving the second output signal, the control module MCU controls the peripheral circuits.

[0097] like Figure 2 The structure shown, the sampling filter submodule 21 in the sampling circuit specifically includes:

[0098] A first sampling filtering unit 211 and a second sampling filtering unit 212 .

[0099] The first output end of the first sampling and filtering unit 211 is connected to the first input end of the isolation submodule 22, and the second output end is connected to the second input end of the isolation submodule 22; the first output end of the second sampling and filtering unit 212 is connected to the third input end of the isolation submodule 22, and the second output end is connected to the fourth input end of the isolation submodule 22.

[0100] Further, according to Figure 2 In the diagram provided, when the circuit is operating normally, the first sampling and filtering unit 211 collects the first-phase sampling signal and outputs the first-phase sampling signal to the isolation submodule 22 for isolation processing, thereby isolating the sampled first sampling signal from the original sampling signal. Similarly, the second sampling and filtering unit 212 collects the second-phase sampling signal and outputs the second-phase sampling signal to the isolation submodule 22 for isolation processing, thereby isolating the sampled second sampling signal from the original sampling signal.

[0101] like Figure 2 The structure shown, the isolation submodule 22 in the sampling circuit specifically includes:

[0102] A first isolation unit 221, a second isolation unit 222 and a third isolation unit 223;

[0103] The first input terminal of the first isolation unit 221 is connected to the first output terminal of the sampling and filtering submodule 21, the second input terminal is connected to the second output terminal of the sampling and filtering submodule 21, and the output terminal is connected to a first node (hereinafter collectively referred to as P1). The first node (hereinafter collectively referred to as P1) is connected to the first input terminal of the comparison module 13 and the first input terminal of the calculation module 12; the first input terminal of the second isolation unit 222 is connected to the third output terminal of the sampling and filtering submodule 21, the second input terminal is connected to the fourth output terminal of the sampling and filtering submodule 21, and the output terminal is connected to the first node (hereinafter collectively referred to as P1); the input terminal of the third isolation unit 223 is connected to the output terminal of the power supply voltage VCC, and the output terminal is connected to the second input terminal of the calculation module 12.

[0104] like Figure 2 The provided diagram illustrates a possible example scenario in which, during normal circuit operation, two corresponding sampling signals are collected by the sampling and filtering submodule 21. The first sampling signal collected from the first phase is input as an input signal to the first isolation unit 221. Through the isolation processing of the first isolation unit 221, a stable first sampling signal is obtained after isolation. Similarly, the second sampling signal collected from the second phase is input as an input signal to the second isolation unit 222. Through the isolation processing of the second isolation unit 222, a stable second sampling signal is obtained after isolation. After adjusting the external power supply voltage VCC, a stable reference signal is output as the reference voltage signal of the third isolation unit 223. The first and second sampling signals are processed in parallel and serve as input signals to the comparison module 13. They are compared with the reference voltage signal to generate a control signal, which is then input to the control module MCU. The control module MCU analyzes and controls the peripheral circuits. Simultaneously, the first and second sampling signals, after being processed in parallel, serve as an input to the calculation module 12 and are processed together with the reference signal output by the third isolation unit 223 to output the third phase equivalent sampling signal. The third-phase equivalent sampling signal is input as the second control signal to the control module MCU, which analyzes the signal and controls the peripheral circuit to sample the two-phase circuit and control the three-phase sampling circuit.

[0105] An embodiment of the present invention provides a sampling circuit that randomly samples two phases of a three-phase circuit by providing a first sampling filter unit and a second sampling filter unit to obtain a first sampling signal and a second sampling signal. The first sampling signal and the second sampling signal are then outputted after isolation through a first isolation unit and a second isolation unit, respectively. The parallel output of the first sampling signal and the second sampling signal serves as an input signal to a comparison module and is compared with a reference voltage signal to obtain a comparison output signal. The comparison output signal is then input to a control module, which analyzes and controls peripheral circuits. Simultaneously, the external power supply voltage is regulated to provide a voltage signal to a third isolation unit, which also outputs a reference signal. Using Kirchhoff's law of constant current, the parallel signal of the first sampling signal and the second sampling signal serves as an input signal to a calculation module and is processed with the reference signal to obtain an equivalent sampling signal for the third phase. The equivalent sampling signal is then input to a control module, which controls peripheral circuits to achieve the goal of sampling a two-phase circuit to complete the three-phase circuit sampling signal processing, thereby improving sampling accuracy and the controller's I / O port utilization.

[0106] In the following, the first sampling and filtering unit includes: a first impedance element, a second impedance element and a first capacitive reactance element; the second sampling and filtering unit includes: a third impedance element, a fourth impedance element and a second capacitive reactance element; the first isolation unit includes: a first isolator and a fifth impedance element; the second isolation unit includes: a second isolator and a sixth impedance element; the third isolation unit includes: a seventh impedance element, an eighth impedance element and a third isolator; the calculation module includes: a ninth impedance element, a tenth impedance element, an eleventh impedance element, a twelfth impedance element and a calculator; the comparison module includes: a thirteenth impedance element, a fourteenth impedance element, a first comparator, a fifteenth impedance element, a sixteenth impedance element, a seventeenth impedance element and a second comparator; and the control module as an example for introduction. Figure 3 , shows a schematic diagram of the structure of another sampling circuit provided by an embodiment of the present invention. This sampling circuit is described based on the first sampling circuit. Figure 3 The following are also shown:

[0107] A first sampling and filtering unit 211 , a second sampling and filtering unit 212 , a first isolation unit 221 , a second isolation unit 222 , a third isolation unit 223 , a calculation module 12 , a comparison module 13 and a control module (hereinafter collectively referred to as MCU) 14 .

[0108] like Figure 3 The structure shown, the first sampling filter unit 211 in the sampling circuit specifically includes:

[0109] A first impedance element R1, a second impedance element R2 and a first capacitive reactance element C1.

[0110] One end of the first impedance element R1 is connected to one end of the second impedance element R2 and the input terminal U of the first phase sampling circuit, and the other end is connected to the second input terminal of the isolation sub-module 22 and the first ground terminal; the other end of the second impedance element R2 is connected to one end of the first capacitive reactance element C1 and the first input terminal of the isolation sub-module 22; the other end of the first capacitive reactance element C1 is connected to the second ground terminal.

[0111] like Figure 3 In the diagram provided, when the circuit is operating normally, the first sampling circuit samples the first impedance element R1 (sampling resistor) through the input terminal U, generating a first sampling signal. This signal is then filtered by the second impedance element R2 and the first capacitive reactance element C1 to produce a stable first sampling signal. The first sampling signal is then input into the isolation submodule for isolation processing.

[0112] like Figure 3 The structure shown, the second sampling filter unit 212 in the sampling circuit specifically includes:

[0113] a third impedance element R3, a fourth impedance element R4 and a second capacitive reactance element C2.

[0114] One end of the third impedance element R3 is connected to one end of the fourth impedance element R4 and the input terminal V of the second phase sampling circuit, and the other end is connected to the fourth input terminal of the isolation sub-module 22 and the third ground terminal; the other end of the fourth impedance element R4 is connected to one end of the second capacitive reactance element C2 and the third input terminal of the isolation sub-module 22; the other end of the second capacitive reactance element C2 is connected to the fourth ground terminal.

[0115] like Figure 3 In the diagram provided, when the circuit is in normal operation, the third impedance element R3 (sampling resistor) is sampled through the input terminal V of the second sampling circuit to obtain a second sampling signal. This signal is then filtered by the fourth impedance element R4 and the second capacitive reactance element C2 to obtain a stable second sampling signal. The second sampling signal is then input into the isolation submodule for isolation processing.

[0116] like Figure 3 In the structure shown, the first isolation unit 221 in the sampling circuit specifically includes:

[0117] A first isolator U1 and a fifth impedance element R5.

[0118] The first isolator U1 has a non-inverting input terminal connected to the first output terminal of the sampling and filtering submodule 21, a reverse input terminal connected to the second output terminal of the sampling and filtering submodule 21 and the output terminal of the first isolator U1, and an output terminal connected to one end of the fifth impedance element R5; the other end of the fifth impedance element R5 is connected to the first node P1.

[0119] like Figure 3 In the diagram provided, when the circuit is in normal operation, a first sampling signal and a second sampling signal are obtained after processing by the sampling and filtering submodule 21. The first sampling signal is input into the first isolator U1 for isolation processing, isolating the first sampling signal from the original signal. A stable first sampling signal is then obtained through the current limiting effect of the fifth impedance element R5.

[0120] like Figure 3 In the structure shown, the second isolation unit 222 in the sampling circuit specifically includes:

[0121] A second isolator U2 and a sixth impedance element R6;

[0122] The non-inverting input terminal of the second isolator U2 is connected to the third output terminal of the sampling and filtering submodule 21, the reverse input terminal is connected to the fourth output terminal of the sampling and filtering submodule 21 and the output terminal of the second isolator U2, and the output terminal is connected to one end of the sixth impedance element R6; the other end of the sixth impedance element R6 is connected to the first node P1.

[0123] like Figure 3 In the diagram provided, when the circuit is in normal operation, a first sampling signal and a second sampling signal are obtained after processing by the sampling and filtering submodule 21. The second sampling signal is input into the second isolator U2 for isolation processing, isolating the second sampling signal from the original signal. A stable second sampling signal is then obtained through the current limiting effect of the sixth impedance element R6.

[0124] like Figure 3 In the structure shown, the third isolation unit 223 in the sampling circuit specifically includes:

[0125] a seventh impedance element R7, an eighth impedance element R8 and a third isolator U3.

[0126] One end of the seventh impedance element R7 is connected to the output end of the power supply voltage VCC, and the other end is connected to one end of the eighth impedance element R8 and the non-inverting input end of the third isolator U3; the other end of the eighth impedance element R8 is connected to the fifth ground end; the inverting input end of the third isolator U3 is connected to the output end of the third isolator U3, and the output end is connected to the second input end of the computing module 12.

[0127] like Figure 3 In the diagram provided, when the circuit is in normal operation, the external power supply voltage VCC is adjusted to generate a reference signal through voltage division by the seventh and eighth impedance elements R7 and R8. The reference signal is then input into the third isolator U3 for isolation processing, isolating the reference signal from the original signal to produce a stable reference signal.

[0128] like Figure 3The structure shown, the calculation module 12 in the sampling circuit specifically includes:

[0129] a ninth impedance element R9, a tenth impedance element R10, an eleventh impedance element R11, a twelfth impedance element R12 and a calculator U4.

[0130] One end of the ninth impedance element R9 is connected to the first node P1, and the other end is connected to one end of the eleventh impedance element R11 and the inverting input terminal of the calculator U4; the other end of the eleventh impedance element R11 is connected to the output terminal of the calculator U4 and the second input terminal of the comparison module 13; one end of the tenth impedance element R10 is connected to the third output terminal of the isolation submodule 22, and the other end is connected to one end of the twelfth impedance element R12 and the non-inverting input terminal of the calculator U4; the other end of the twelfth impedance element R12 is connected to the sixth ground terminal.

[0131] like Figure 3 The diagram provided shows that when the circuit is in normal working condition, according to Kirchhoff's law of constant current:

[0132] I u +I v +I w =0 Formula 1

[0133] The current of the third phase W is calculated. The sampled signal is input to the inverting input terminal of the calculator U4 through the current limiting function of the ninth impedance element R9. The non-inverting input terminal of the calculator U4 is connected to the third phase reference signal. The reference signal is obtained by isolating the power supply voltage Vcc through the isolation function of the isolation submodule 22 to obtain a stable reference signal. The reference signal is then output to the tenth impedance element R10. The reference signal is then output to the non-inverting input terminal of the calculator U4 through the voltage division function of the twelfth impedance element R12. The reference signal and the sampled signal are combined to calculate the equivalent sampling voltage signal of the third phase in the current sampling state.

[0134] The voltage signal obtained at the inverting output terminal of the calculator U4 is obtained by the following formula:

[0135]

[0136] Among them, U 01 is the voltage signal of the reverse output terminal of the calculator U4, U U is the voltage at the first phase voltage U terminal, U V is the voltage at the second phase voltage V terminal.

[0137] The voltage signal obtained at the same-direction output terminal of the calculator U4 is obtained by the following formula:

[0138]

[0139] Among them, U 02 It is the voltage signal of the same-direction output terminal of the calculator U4, VCC is the external power supply voltage.

[0140] According to the voltage signals at the two output terminals of the calculator U4, the equivalent sampling signal of the third phase is obtained as shown in Formula 4:

[0141]

[0142] Among them, U0 is the third phase equivalent sampling signal.

[0143] like Figure 3 The structure shown, the comparison module 13 in the sampling circuit specifically includes:

[0144] The thirteenth impedance element R13, the fourteenth impedance element R14, the first comparator U5, the fifteenth impedance element R15, the sixteenth impedance element R16, the seventeenth impedance element R17 and the second comparator U6.

[0145] One end of the thirteenth impedance element R13 is connected to the reference voltage V ref The output end of the 14th impedance element R14 is connected to one end of the 14th impedance element R14 and the non-inverting input end of the first comparator U5; the other end of the 14th impedance element R14 is connected to the seventh ground end; the inverting input end of the first comparator U5 is connected to the first node P1, and the output end is connected to the first input end of the control module MCU; one end of the 15th impedance element R15 is connected to the output end of the calculation module 12, and the other end is connected to the inverting input end of the second comparator U6; one end of the 16th impedance element R16 is connected to the reference voltage V ref The output end of the second comparator U6 is connected to the second input end of the control module MCU, and the other end is connected to one end of the seventeenth impedance element R17 and the same-direction input end of the second comparator U6; the other end of the seventeenth impedance element R17 is connected to the eighth ground end; the output end of the second comparator U6 is connected to the second input end of the control module MCU.

[0146] like Figure 3 In the diagram provided, when the circuit is in normal working state, the sampling filter submodule randomly collects two phase sampling signals from the three phase electrical signals U, V, and W, and the isolation submodule isolates the two phase sampling signals to obtain a stable first sampling signal and a second sampling signal. The first comparator U5 uses one of the two phase sampling signals as an input signal and compares it with the reference voltage signal V ref The output signal is compared and input to the control module MCU, which controls the peripheral circuit after analysis. At the same time, the equivalent sampling signal obtained by the calculation module 12 is used as the input signal of the second comparator U6 and compared with the reference voltage signal V refThe comparison is then performed and the output signal is input as another control signal to the control module MCU. After the control module MCU analyzes the control signal, it performs corresponding control on the peripheral circuits. This achieves the goal of sampling two phases to complete the three-phase sampling process, improving sampling accuracy and the utilization rate of the controller's IO ports.

[0147] In a possible example scenario, any two phases of U, V, and W in the three-phase electricity are sampled by the first sampling and filtering unit and the second sampling and filtering unit to obtain two-phase sampling signals. For example, after obtaining the sampling signals of the U and V phases, the equivalent sampling current of the W phase is calculated according to Kirchhoff's constant current law. The U phase passes through the sampling resistor R1, is filtered by R2 and C1, and is input to the isolated output of the voltage isolator U1 (the isolator isolates the sampled voltage signal from the original signal). The output is connected to R5 to obtain a stable sampling signal; the V phase passes through the sampling resistor R3, is filtered by R4 and C2, and is connected to the isolated output of the voltage isolator U2, and the output is connected to R6; the sampled signal is then connected to the inverting input terminal of the calculator U4 (the sampled signal and the preset signal are used to calculate the equivalent sampling current of the third phase) through the current limiting function of R9. The non-inverting terminal of the calculator U4 inputs the reference signal for the third phase signal. The reference signal is the power supply voltage Vcc divided by R7 and R8 and connected to the non-inverting input terminal of the voltage isolator U3. The output is connected to R10. Then, this voltage is divided by R12 and connected to the non-inverting input terminal of the calculator U4. It works together with the sampled signal to calculate the equivalent sampling signal of the third phase in the current sampling state. The output signal of calculator U4 is connected to one end of comparator U6 through the current limiting protection function of R13. The other end of comparator U6 is the voltage divided by reference voltage Vref on R17. The specific sampled signal and reference signal are connected to the other end of comparator U6, depending on the effective level of the corresponding microcontroller port (U5 and U6 are comparators, and their output depends on the levels of the two input ports of U5 and U6. When the reverse input is higher than the forward input level, the comparators U5 and U6 output negative logic, otherwise it is positive logic. If the microcontroller port is also valid at a low level, the function will be triggered only when the port of the microcontroller MCU is at a low level. At this time, the function is triggered). If the microcontroller is negative logic valid, then when overcurrent occurs, the comparator should output negative logic. In this case, the reverse input of the comparator should be greater than the non-inverting input. Therefore, the sampled signal should be connected to the reverse input of the comparator, and the reference voltage should be connected to the non-inverting input of the comparator, as connected in this solution; connected to the non-inverting input of comparator U6, and the output of comparator U6 is connected to the microcontroller MCU, and the state of the corresponding motor is controlled by the microcontroller MCU.

[0148] An embodiment of the present invention provides an overcurrent protection circuit. By providing a first sampling filter submodule and a second sampling filter submodule, the circuit randomly collects two-phase sampling signals from a three-phase electrical signal, and outputs stable sampling signals through the isolation function of a first isolation unit and a second isolation unit. A stable reference signal is then obtained by adjusting the reference voltage. The collected signal is then used as the input signal of a calculation module and processed with the reference signal to obtain a third-phase equivalent sampling signal. A comparison module compares the third-phase equivalent sampling signal with the reference signal, outputs a final control signal, and inputs it to a control module. The control module analyzes the signal and controls the peripheral circuit accordingly. Simultaneously, the sampling signal is retained as an input terminal of the comparison module, which compares it with the reference voltage signal and outputs another control signal. Similarly, the control module analyzes the signal and controls the peripheral circuit accordingly. This achieves the goal of completing three-phase sampling processing by sampling a two-phase circuit, improving sampling accuracy and the utilization rate of the controller's IO ports.

[0149] Based on the sampling circuit provided in the above embodiment, the present invention further provides an electronic device, which includes the sampling circuit provided in the above embodiment.

[0150] In a possible design, the electronic device may be, but is not limited to, an air-conditioning device, a television device, or a refrigerator device, or any electronic device that needs to use the sampling circuit structure of the present invention.

[0151] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sampling circuit, characterized in that: include: Sampling isolation module, calculation module, comparison module and control module; The input end of the sampling isolation module is connected to the output end of the sampling circuit, the first output end is connected to the first input end of the comparison module, the second output end is connected to the first input end of the calculation module, and the third output end is connected to the second input end of the calculation module; The output terminal of the calculation module is connected to the second input terminal of the comparison module; The first output terminal of the comparison module is connected to one terminal of the control module, and the second output terminal is connected to the other terminal of the control module; The sampling isolation module obtains a sampling current signal when determining the sampling current of the two-phase circuit, and isolates the initial sampling voltage signal corresponding to the sampling current signal to obtain a stable sampling voltage signal; The calculation module receives the stable voltage signal output by the sampled current of the two-phase circuit and the reference voltage provided by the third-phase voltage, and outputs the equivalent sampled voltage signal of the third-phase circuit through calculation processing; The comparison module compares the sampled voltage signal output by the sampling isolation module with the reference voltage signal to provide a control signal to the control module; and compares the equivalent sampled voltage signal output by the calculation module with the reference voltage signal to provide another control signal to the control module; The control module controls the peripheral circuit accordingly after receiving the control signal.

2. The circuit according to claim 1, wherein: The sampling and isolation module includes: a sampling and filtering submodule and an isolation submodule; The output terminals of the sampling and filtering submodule are sequentially connected to the input terminals of the isolation submodule; The first output terminal of the isolation submodule is connected to the second output terminal and the first node, the first node is connected to the first input terminal of the comparison module and the first input terminal of the calculation module, and the third output terminal is connected to the second input terminal of the calculation module.

3. The circuit according to claim 2, characterized in that The sampling and filtering submodule includes: a first sampling and filtering unit and a second sampling and filtering unit; The first output end of the first sampling and filtering unit is connected to the first input end of the isolation submodule, and the second output end is connected to the second input end of the isolation submodule; The first output terminal of the second sampling and filtering unit is connected to the third input terminal of the isolation submodule, and the second output terminal of the second sampling and filtering unit is connected to the fourth input terminal of the isolation submodule.

4. The circuit according to claim 3, characterized in that The first sampling and filtering unit includes: a first impedance element, a second impedance element and a first capacitive reactance element; One end of the first impedance element is connected to one end of the second impedance element and the input end of the first phase sampling circuit, and the other end is connected to the second input end of the isolation submodule and the first ground end; The other end of the second impedance element is connected to one end of the first capacitive reactance element and the first input end of the isolation submodule; The other end of the first capacitive reactance element is connected to the second ground end.

5. The circuit according to claim 3, characterized in that The second sampling and filtering unit includes: a third impedance element, a fourth impedance element and a second capacitive reactance element; One end of the third impedance element is connected to one end of the fourth impedance element and the input end of the second phase sampling circuit, and the other end is connected to the fourth input end of the isolation submodule and the third ground end; The other end of the fourth impedance element is connected to one end of the second capacitive reactance element and the third input end of the isolation submodule; The other end of the second capacitive reactance element is connected to the fourth ground end.

6. The circuit according to claim 2, characterized in that The isolation submodule includes: a first isolation unit, a second isolation unit and a third isolation unit; The first input terminal of the first isolation unit is connected to the first output terminal of the sampling and filtering submodule, the second input terminal is connected to the second output terminal of the sampling and filtering submodule, and the output terminal is connected to a first node, and the first node is connected to the first input terminal of the comparison module and the first input terminal of the calculation module; The first input terminal of the second isolation unit is connected to the third output terminal of the sampling and filtering submodule, the second input terminal is connected to the fourth output terminal of the sampling and filtering submodule, and the output terminal is connected to the first node; The input end of the third isolation unit is connected to the power supply voltage output end, and the output end is connected to the second input end of the calculation module.

7. The circuit according to claim 6, characterized in that The first isolation unit includes: a first isolator and a fifth impedance element; The non-inverting input terminal of the first isolator is connected to the first output terminal of the sampling and filtering submodule, the reverse input terminal is connected to the second output terminal of the sampling and filtering submodule and the output terminal of the first isolator, and the output terminal is connected to one end of the fifth impedance element; The other end of the fifth impedance element is connected to the first node.

8. The circuit according to claim 6, characterized in that The second isolation unit includes: a second isolator and a sixth impedance element; The non-inverting input terminal of the second isolator is connected to the third output terminal of the sampling and filtering submodule, the reverse input terminal is connected to the fourth output terminal of the sampling and filtering submodule and the output terminal of the second isolator, and the output terminal is connected to one end of the sixth impedance element; The other end of the sixth impedance element is connected to the first node.

9. The circuit according to claim 6, characterized in that The third isolation unit includes: a seventh impedance element, an eighth impedance element and a third isolator; One end of the seventh impedance element is connected to the output end of the power supply voltage, and the other end is connected to one end of the eighth impedance element and the non-inverting input end of the third isolator; The other end of the eighth impedance element is connected to the fifth ground terminal; The inverting input terminal of the third isolator is connected to the output terminal of the third isolator, and the output terminal is connected to the second input terminal of the calculation module.

10. The circuit according to claim 2, characterized in that The calculation module includes: a ninth impedance element, a tenth impedance element, an eleventh impedance element, a twelfth impedance element, and a calculator; One end of the ninth impedance element is connected to the first node, and the other end is connected to one end of the eleventh impedance element and the inverting input terminal of the calculator; The other end of the eleventh impedance element is connected to the output end of the calculator and the second input end of the comparison module; One end of the tenth impedance element is connected to the third output end of the isolation submodule, and the other end is connected to one end of the twelfth impedance element and the same-direction input end of the calculator; The other end of the twelfth impedance element is connected to the sixth ground end.

11. The circuit according to claim 1, wherein: The comparison module includes: a thirteenth impedance element, a fourteenth impedance element, a first comparator, a fifteenth impedance element, a sixteenth impedance element, a seventeenth impedance element, and a second comparator; One end of the thirteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the fourteenth impedance element and the non-inverting input end of the first comparator; The other end of the fourteenth impedance element is connected to the seventh ground terminal; The inverting input terminal of the first comparator is connected to the first node, and the output terminal is connected to the first input terminal of the control module; One end of the fifteenth impedance element is connected to the output end of the calculation module, and the other end is connected to the inverting input end of the second comparator; One end of the sixteenth impedance element is connected to the output end of the reference voltage, and the other end is connected to one end of the seventeenth impedance element and the non-inverting input end of the second comparator; The other end of the seventeenth impedance element is connected to the eighth ground terminal; An output terminal of the second comparator is connected to a second input terminal of the control module.

12. An electronic device, characterized in that: The electronic device comprises the sampling circuit according to any one of claims 1 to 11.

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