Analog quantity self-calibration circuit and analog quantity self-calibration device

Abstract

The utility model discloses an analog quantity self-calibration circuit and an analog quantity self-calibration device. The circuit comprises a first selection circuit, an analog circuit and a first control circuit. A first input end and a second input end of the first selection circuit are connected with external equipment to receive an analog input signal, and a third input end and a fourth input end are connected with a first reference signal source; the first input end and the second input end of the analog circuit are respectively connected with the first output end and the second output end of the first selection circuit; the input end of the first control circuit is connected with the output end of the analog circuit, and the output end is connected with the control end of the first selection circuit; during power-on, the first control circuit controls the first selection circuit to connect the first reference signal source to the analog circuit, and after the analog circuit processes a signal, the signal is output to the first control circuit and then is connected with an analog input signal to realize self-calibration. According to the invention, the measurement precision and the measurement efficiency of the analog signal can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of analog circuit, in particular to an analog quantity self-calibration circuit and an analog quantity self-calibration device. BACKGROUND

[0002] At present, in the analog signal collection system, due to the influence of environmental factors and the aging of hardware devices after long-time operation, the collected analog signals often have errors, for example, the analog signals have offset errors.

[0003] In order to solve the offset error, the existing PLC (Programmable Logic Controller) device completes the calibration operation before leaving the factory to reduce the offset error of the PLC device. However, the external device connected with the PLC device is the collection interface of the analog signal, and since the PLC device can be connected with different external devices, the calibration of the external device and the PLC device is completed after leaving the factory, which leads to high calibration difficulty and low calibration efficiency of the analog signal. CONTENT OF THE INVENTION

[0004] In order to solve the above problems, the present application provides an analog quantity self-calibration circuit and an analog quantity self-calibration device.

[0005] The present application provides an analog quantity self-calibration circuit, comprising:

[0006] A first selection circuit, first and second input ends of the first selection circuit are connected with external devices respectively, for receiving analog input signals, third and fourth input ends of the first selection circuit are connected with first reference signal sources respectively;

[0007] An analog circuit, a first input end of the analog circuit is connected with a first output end of the first selection circuit, a second input end of the analog circuit is connected with a second output end of the first selection circuit;

[0008] A first control circuit, an input end of the first control circuit is connected with an output end of the analog circuit, an output end of the first control circuit is connected with a control end of the first selection circuit, the first control circuit is used for controlling the third input end and the first output end of the first selection circuit to be connected, the fourth input end and the second output end of the first selection circuit to be connected when power-on, and the analog circuit is connected with the first reference signal source through the first selection circuit;

[0009] The first control circuit is used for controlling the first input end and the first output end of the first selection circuit to be connected, the second input end and the second output end of the first selection circuit to be connected, and the analog circuit is used for receiving the analog input signal through the first selection circuit.

[0010] The first selection circuit comprises a double-pole double-throw switch and a first relay, the first input end and the second input end of the double-pole double-throw switch are connected with the external device respectively, the third input end and the fourth input end of the double-pole double-throw switch are connected with the first reference signal source respectively, the first relay is connected with the output end of the first control circuit, and the first relay is arranged apart from the double-pole double-throw switch.

[0011] The first control circuit is used for controlling the first relay to work when power is on, the third input end and the first output end of the double-pole double-throw switch are connected, and the fourth input end and the second output end of the double-pole double-throw switch are connected.

[0012] The first control circuit is used for controlling the first relay to stop working, the first input end and the first output end of the double-pole double-throw switch are connected, and the second input end and the second output end of the double-pole double-throw switch are connected.

[0013] The first control circuit comprises a controller, a first resistor, a second resistor, a first switch tube and a first diode, the input end of the controller is connected with the output end of the analog circuit, and the analog input signal is calibrated based on the first reference signal of the first reference signal source;

[0014] The analog circuit is used for receiving the analog signal from the first selection circuit and adjusting the output value of the analog signal to the range that can be received by the controller.

[0015] The output end of the controller is connected with the control end of the first switch tube through the first resistor, the second resistor is connected between the control end and the first end of the first switch tube, the first end of the first switch tube is grounded, the second end of the first switch tube is connected with the first end of the first relay, the second end of the first switch tube is connected with the second end of the first relay through the first diode, and the second end of the first relay receives the first reference voltage.

[0016] The controller is used for controlling the first switch tube to be turned on and the first relay to work, and the controller is used for controlling the first switch tube to be turned off and the first relay to stop working.

[0017] The analog self-calibration circuit further comprises at least one second selection circuit and at least one second control circuit, the second selection circuit is connected between the first selection circuit and the external device, the second control circuit is connected with the controller, and the second control circuit is connected with the control end of the second selection circuit.

[0018] The first and second input terminals of the second selection circuit are respectively connected to the external device, the third and fourth input terminals of the second selection circuit are respectively connected to the second reference signal source, the first output terminal of the second selection circuit is connected to the first input terminal of the first selection circuit, the second output terminal of the second selection circuit is connected to the second input terminal of the first selection circuit, and the output terminal of the second control circuit is connected to the control terminal of the second selection circuit.

[0019] The second control circuit includes a third resistor, a fourth resistor, a second switch, and a second diode. The output terminal of the controller is connected to the control terminal of the second switch through the third resistor. The fourth resistor is connected between the control terminal and the first terminal of the second switch. The first terminal of the second switch is grounded. The second terminal of the second switch is connected to the first terminal of the second relay of the second selection circuit. The second terminal of the second switch is connected to the second terminal of the second relay through the second diode. The second terminal of the second relay receives the first reference voltage.

[0020] The analog self-calibration circuit further includes multiple second selection circuits and multiple second control circuits. The multiple second selection circuits are sequentially connected between the first selection circuit and the external device. The multiple second control circuits are connected to the controller, and each second control circuit is connected to the control terminal of the corresponding second selection circuit.

[0021] This application also provides an analog self-calibration device, including an external device, a first selection circuit, a first control circuit, multiple second selection circuits, multiple second control circuits, and an analog circuit. Through the above-mentioned analog self-calibration circuit, the analog signal input from the external device is automatically calibrated.

[0022] The beneficial effects of this application are as follows: The input terminal of the first control circuit is connected to the output terminal of the analog circuit, and the output terminal of the first control circuit is connected to the control terminal of the first selection circuit. The first control circuit controls the connection of the third input terminal and the first output terminal of the first selection circuit during power-on. The fourth input terminal and the second output terminal of the first selection circuit are also connected. The analog circuit is connected to the first reference signal source through the first selection circuit. Furthermore, the first control circuit controls the connection of the first input terminal and the first output terminal of the first selection circuit, and the second input terminal and the second output terminal of the first selection circuit are also connected. The analog circuit receives analog input signals through the first selection circuit. By connecting the analog circuit to the first reference signal source through the first selection circuit during power-on, calibration signals are acquired, and the analog input signals can be calibrated based on the calibration signals. This power-on calibration is easy to implement and improves calibration efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0024] Figure 1 This is a circuit diagram of the first embodiment of the analog self-calibration circuit provided in this application;

[0025] Figure 2 This is a circuit diagram of the second embodiment of the analog self-calibration circuit provided in this application.

[0026] Reference numerals in the figures: First selection circuit 100, First reference signal source 101, External device 102, First relay 103, Double-pole double-throw switch 104, First input terminal of the first selection circuit 105, Third input terminal of the first selection circuit 106, Second input terminal of the first selection circuit 107, Fourth input terminal of the first selection circuit 108, First output terminal of the first selection circuit 109, Second output terminal of the first selection circuit 110, Second selection circuit 111, Second reference signal source 112, First input terminal of the second selection circuit 113, Fourth input terminal of the second selection circuit 114. Three-input terminal; 115. Second input terminal of the second selection circuit; 116. Fourth input terminal of the second selection circuit; 117. First output terminal of the second selection circuit; 118. Second output terminal of the second selection circuit; 200. Analog circuit; 300. First control circuit; 301. Controller; 302. First resistor; 303. First diode; 304. First switching transistor; 305. Second control circuit; 306. Third resistor; 307. Fourth resistor; 308. Second switching transistor; 309. Second diode; 310. Second relay; 311. First reference voltage; 312. Detailed Implementation

[0027] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0029] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0032] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0033] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a connection between two components or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0034] This application provides an analog self-calibration circuit; please refer to [link / reference]. Figures 1 to 2 As shown. Figure 1 This is a circuit diagram of the first embodiment of the analog self-calibration circuit provided in this application; Figure 2 This is a circuit diagram of the second embodiment of the analog self-calibration circuit provided in this application.

[0035] The analog self-calibration circuit of this embodiment includes a first selection circuit 100, an analog circuit 200, and a first control circuit 300.

[0036] In this circuit, the first input terminal 105 and the second input terminal 107 of the first selection circuit 100 are respectively connected to the external device 102 to receive the analog input signal output by the external device 102. The third input terminal 106 and the fourth input terminal 108 of the first selection circuit 100 are respectively connected to the first reference signal source 101. The first reference signal source 101 can be a ground reference signal source, that is, the third input terminal 106 and the fourth input terminal 108 of the first selection circuit 100 are respectively grounded; in other embodiments, the first reference signal source 101 can be other signal sources, which will not be described in detail here.

[0037] The first input terminal of the analog circuit 200 is connected to the first output terminal 109 of the first selection circuit 100, and the second input terminal of the analog circuit 200 is connected to the second output terminal 110 of the first selection circuit 100.

[0038] In this circuit, the input terminal of the first control circuit 300 is connected to the output terminal of the analog circuit 200, and the output terminal of the first control circuit 300 is connected to the control terminal of the first selection circuit 100. During power-on, i.e., when the analog self-calibration circuit is powered on, the first control circuit 300 controls the connection of the third input terminal 106 and the first output terminal 109 of the first selection circuit 100, and the connection of the fourth input terminal 108 and the second output terminal 110, so that the first and second input terminals of the analog circuit 200 receive the first reference signal GND. At this time, the first control circuit 300 obtains the calibration signal from the analog circuit 200.

[0039] After the first control circuit 300 obtains the calibration signal from the analog circuit 200, the first control circuit 300 controls the first input terminal 105 and the first output terminal 109 of the first selection circuit 100 to be connected, and the second input terminal 107 and the second output terminal 110 to be connected, so that the analog circuit 200 receives the analog input signal. At this time, the first control circuit 300 obtains the analog input signal from the analog circuit 200.

[0040] In some embodiments, the first control circuit 300 further calibrates the analog input signal according to the calibration signal. The first control circuit 300 calibrates the analog input signal according to the calibration signal using existing calibration methods, which will not be described in detail here.

[0041] In this embodiment, the input terminal of the first control circuit 300 is connected to the output terminal of the analog circuit 200, and the output terminal of the first control circuit 300 is connected to the control terminal of the first selection circuit 100. The first control circuit 300 controls the connection of the third input terminal 106 and the first output terminal 109 of the first selection circuit 100 during power-on, and connects the fourth input terminal 108 and the second output terminal 110 of the first selection circuit 100. The analog circuit 200 is connected to the first reference signal source 101 through the first selection circuit 100. The first control circuit 300 controls the connection of the first input terminal 105 and the first output terminal 109 of the first selection circuit 100, and connects the second input terminal 107 and the second output terminal 110 of the first selection circuit 100. The analog circuit 200 receives analog input signals through the first selection circuit 100. By connecting the analog circuit 200 to the first reference signal source 101 through the first selection circuit 100 during power-on, calibration signals are acquired, enabling calibration of the analog input signal based on the calibration signal. This power-on calibration is easy to implement and improves calibration efficiency.

[0042] In some embodiments, the first reference signal source 101 is a ground reference signal source, the external device 102 outputs an analog input signal, the first input terminal 105 and the second input terminal 107 of the first selection circuit 100 constitute a differential input signal pair, and the third input terminal 106 and the fourth input terminal 108 of the first selection circuit 100 constitute a differential input signal pair.

[0043] The first output terminal 109 and the second output terminal 110 of the first selection circuit 100 form a differential output signal pair. The first output terminal 109 and the second output terminal 110 of the first selection circuit 100 are respectively connected to the first input terminal and the second input terminal of the analog circuit 200 to output a differential signal to the analog circuit 200. The differential signal can be a calibration signal output by the first reference signal source 101 or an analog input signal output by the external device 102. The analog circuit 200 processes the differential signal output by the first selection circuit 100 to ensure that the signal output value meets the input requirements of the first control circuit 300.

[0044] The input terminal of the first control circuit 300 is connected to the output terminal of the analog circuit 200, and is used to receive the calibration signal or analog input signal processed by the analog circuit 200. The output terminal of the first control circuit 300 is connected to the control terminal of the first selection circuit 100, and is used to output a control signal to the first selection circuit 100.

[0045] Specifically, when powered on, the first control circuit 300 controls the third input terminal 106 and the fourth input terminal 108 of the first selection circuit 100 to be connected to the first output terminal 109 and the second output terminal 110 of the first selection circuit 100, respectively. At this time, the analog circuit 200 is connected to the first reference signal source 101 through the first selection circuit 100, and the first control circuit 300 obtains the calibration signal from the analog circuit 200.

[0046] After acquiring the calibration signal, the first control circuit 300 controls the first input terminal 105 and the second input terminal 107 of the first selection circuit 100 to be connected to the first output terminal 109 and the second output terminal 110 of the first selection circuit 100, respectively. At this time, the analog circuit 200 receives the analog input signal through the first selection circuit 100, and the first control circuit 300 acquires the analog input signal from the analog circuit 200. The first control circuit 300 further calibrates the analog input signal according to the calibration signal.

[0047] In some embodiments, the first control circuit 300 selects different input signals by sending a control signal to the first selection circuit 100. The first control circuit 300 first controls the first selection circuit 100 to connect to the first reference signal source 101 to obtain a calibration signal. Then, it controls the first selection circuit 100 to receive the analog input signal and uses the calibration signal to perform zero-point calibration on the analog input signal. Without human intervention, the first control circuit 300 automatically calibrates the analog input signal from the external device 102, thereby improving calibration efficiency and accuracy.

[0048] According to some embodiments of this application, such as Figure 1 and Figure 2 As shown, the first selection circuit 100 in this embodiment includes a double-pole double-throw switch 104 and a first relay 103.

[0049] The first and second input terminals of the double-pole double-throw switch 104 are connected to the external device 102, respectively, and the third and fourth input terminals of the double-pole double-throw switch 104 are connected to the first reference signal source 101, respectively.

[0050] The first and second input terminals of the double-pole double-throw switch 104 serve as the first input terminal 105 and the second input terminal 107 of the first selection circuit 100, respectively. The third and fourth input terminals of the double-pole double-throw switch 104 serve as the third input terminal 106 and the fourth input terminal 108 of the first selection circuit 100, respectively. The first and second output terminals of the double-pole double-throw switch 104 serve as the first output terminal 109 and the second output terminal 110 of the first selection circuit 100, respectively.

[0051] The first relay 103 is connected to the output terminal of the first control circuit 300, and the first relay 103 is spaced apart from the double-pole double-throw switch 104 to control the state switching of the double-pole double-throw switch 104.

[0052] The first control circuit 300 controls the first relay 103 to operate during power-on. At this time, the third input and first output terminals of the double-pole double-throw switch 104 are connected, as are the fourth input and second output terminals. The analog circuit 200 is connected to the first reference signal source 101 via the double-pole double-throw switch 104. When the first control circuit 300 stops the first relay 103 from operating, the first input and first output terminals of the double-pole double-throw switch 104 are connected, as are the second input and second output terminals. The analog circuit 200 receives analog input signals via the double-pole double-throw switch 104.

[0053] In this embodiment, a double-pole double-throw switch 104 is used to synchronously switch the first input terminal 105 and the second input terminal 107 of the first selection circuit 100 to the third input terminal 106 and the fourth input terminal 108, respectively, which are connected to the first output terminal 109 and the second output terminal 110. This ensures that the reference signal and the analog input signal follow exactly the same physical path, eliminating phase errors caused by path asymmetry. Physical isolation and control are achieved through the first relay 103, reducing the risk of interference to the first reference signal source 101.

[0054] According to some embodiments of this application, such as Figure 1 As shown, the first control circuit 300 in this embodiment includes a controller 301, a first resistor 302, a second resistor 303, a first switching transistor 305, and a first diode 304.

[0055] In this embodiment, the controller 301 can be a PLC device. The input terminal of the controller 301 is connected to the output terminal of the analog circuit 200. The controller 301 obtains calibration signals or analog input signals from the analog circuit 200, and calibrates the analog input signals based on the calibration signals.

[0056] The output terminal of the controller 301 is connected to the control terminal of the first switch 305 through the first resistor 302. The second resistor 303 is connected between the control terminal and the first terminal of the first switch 305. The first terminal of the first switch 305 is grounded. The second terminal of the first switch 305 is connected to the first terminal of the first relay 103. The second terminal of the first switch 305 is connected to the second terminal of the first relay 103 through the first diode 304. The second terminal of the first relay 103 receives the first reference voltage 312, which can be 24V.

[0057] The controller 301 outputs a control signal CTR to the control terminal of the first switching transistor 305 through its output terminal, which is used to control the first relay 103 and then control the first selection circuit 100.

[0058] In some embodiments, when the control signal CTR of the controller 301 is high, the first switch 305 is turned on, the first relay 103 operates, and the third and fourth input terminals of the double-pole double-throw switch 104 are connected to the first and second input terminals, respectively. At this time, the analog circuit 200 is connected to the first reference signal source 101 through the double-pole double-throw switch 104, and the controller 301 obtains the calibration signal from the analog circuit 200.

[0059] After acquiring the calibration signal, the controller 301's control signal CTR goes low, the first switch 305 is turned off, the first relay 103 stops working, and the first and second input terminals of the double-pole double-throw switch 104 are connected to the first and second output terminals, respectively. At this time, the analog circuit 200 is connected to the external device 102 through the double-pole double-throw switch 104, and the controller 301 acquires the analog input signal from the analog circuit 200. The controller 301 uses the calibration signal to perform zero-point calibration on the analog input signal.

[0060] The first control circuit 300 in this embodiment includes a controller 301, a first resistor 302, a second resistor 303, a first switching transistor 305, and a first diode 304. The controller 301 performs zero-point calibration on the processed analog input signal based on the processed reference signal, thereby improving the calibration efficiency and accuracy of the analog input signal.

[0061] According to some embodiments of this application, such as Figure 2 As shown, the analog self-calibration circuit of this embodiment further includes at least one second selection circuit 111 and at least one second control circuit 306. The second selection circuit 111 is connected between the first selection circuit 100 and the external device 102. The first input terminal 113 and the second input terminal 115 of the second selection circuit 111 are used to connect to the external device 102, the third input terminal 114 and the fourth input terminal 116 are connected to the second reference signal source 112, and the first output terminal 117 and the second output terminal 118 are respectively connected to the first input terminal 105 and the second input terminal 107 of the first selection circuit 100.

[0062] The second control circuit 306 is connected to the controller 301 and is used to drive the second selection circuit 111 according to the control signal.

[0063] Specifically, the second control circuit 306 includes a third resistor 307, a fourth resistor 308, a second switch 309, and a second diode 310. The output terminal of the controller 301 is connected to the control terminal of the second switch 309 through the third resistor 307. The fourth resistor 308 is connected between the control terminal and the first terminal of the second switch 309. The first terminal of the second switch 309 is grounded. The second terminal of the second switch 309 is connected to the first terminal of the second relay 311 in the second selection circuit 111 and is connected to the second terminal of the second relay 311 through the second diode 310. The second terminal of the second relay 311 receives the first reference voltage 312.

[0064] In some embodiments, the second reference signal source 112 is a full-scale voltage reference signal source. The full-scale voltage reference signal source is used to output a high-precision, high-stability voltage value that corresponds to the maximum value of the analog input signal that the controller 301 is allowed to receive.

[0065] The controller 301 controls the first control circuit 300 and the second control circuit 306 in a time-division manner. First, the controller 301 controls the first control circuit 300 to connect the first selection circuit 100 to the first reference signal source 101, i.e., the ground reference signal source. At this time, the analog circuit 200 is connected to the first reference signal source 101 through the first selection circuit, and the controller 301 obtains the first calibration signal from the analog circuit 200.

[0066] Then, the controller 301 controls the second control circuit 306 to connect the second selection circuit 111 to the second reference signal source 112, i.e., the full-scale voltage reference signal source. At this time, the analog circuit 200 is connected to the second reference signal source 112 through the second selection circuit 111 and the first selection circuit 100, and the controller 301 obtains the second calibration signal from the analog circuit 200.

[0067] Controller 301 controls the connection of the first selection circuit 100 and the second selection circuit 111 to the external device 102. At this time, the analog circuit 200 is connected to the external device 102 through the first selection circuit 100 and the second selection circuit 111, and controller 301 obtains the analog input signal from the analog circuit 200. Controller 301 calibrates the analog input signal according to the recorded first calibration signal and second calibration signal to improve the calibration efficiency and accuracy of the analog input signal.

[0068] According to some embodiments of this application, such as Figure 2As shown, the analog self-calibration circuit of this embodiment includes multiple second selection circuits 111 and multiple second control circuits 306. The multiple second selection circuits 111 are sequentially connected between the first selection circuit 100 and the external device 102, and the multiple second control circuits 306 are connected to the controller 301. The multiple second control circuits 306 are also connected to the control terminals of the corresponding second selection circuits 111, together forming a multi-level signal selection channel.

[0069] For example, the analog self-calibration circuit may include three second selection circuits 111, which are sequentially connected between the first selection circuit 100 and the external device 102. Each second selection circuit 111 corresponds to a second control circuit 306.

[0070] The analog self-calibration circuit also includes multiple second reference signal sources 112, such as three second reference signal sources 112. One of the three second reference signal sources 112 provides a reference signal that is the maximum voltage value of the analog signal that the controller 301 is allowed to receive. The other two of the three second reference signal sources 112 provide reference signals that are half of the maximum voltage value of the analog signal that the controller 301 is allowed to receive, and one-quarter of the maximum voltage value of the analog signal that the controller 301 is allowed to receive, respectively.

[0071] The controller 301 sequentially controls all selection circuits to connect to their corresponding reference signal sources via control signals CTR0, CTR1, CTR2, and CTR3 to obtain different calibration signals. Then, it controls all selection circuits to connect to external device 102. The analog circuit 200 is connected to external device 102 via a first selection circuit 100 and multiple second selection circuits 111. The controller 301 obtains the analog input signal from the analog circuit 200. The controller 301 calibrates the analog input signal according to different calibration signals to improve the calibration efficiency and accuracy of the analog input signal.

[0072] This application also provides an analog self-calibration device, which realizes zero-point calibration, full-scale calibration and multi-point calibration of analog input signals through the analog self-calibration circuit disclosed in the above embodiments.

[0073] In summary, the first control circuit 300 of this application controls the connection of the third input terminal 106 and the first output terminal 109 of the first selection circuit 100 when powered on, and connects the fourth input terminal 108 and the second output terminal 110 of the first selection circuit 100. The analog circuit 200 is connected to the first reference signal source 101 through the first selection circuit 100. The first control circuit 300 controls the connection of the first input terminal 105 and the first output terminal 109 of the first selection circuit 100, and connects the second input terminal 107 and the second output terminal 110 of the first selection circuit. The analog circuit 200 receives analog input signals through the first selection circuit 100. When powered on, the analog circuit 200 is connected to the first reference signal source 101 through the first selection circuit 100 to acquire calibration signals. The first control circuit 300 automatically switches the connection state of the first selection circuit 100, thereby enabling automatic calibration of the analog input signal based on the calibration signal, improving calibration efficiency and accuracy.

[0074] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An analog self-calibration circuit, characterized in that, include: A first selection circuit, wherein the first input terminal and the second input terminal of the first selection circuit are respectively connected to an external device for receiving analog input signals, and the third input terminal and the fourth input terminal of the first selection circuit are respectively connected to a first reference signal source; An analog circuit, wherein a first input terminal of the analog circuit is connected to a first output terminal of the first selection circuit, and a second input terminal of the analog circuit is connected to a second output terminal of the first selection circuit; A first control circuit, wherein the input terminal of the first control circuit is connected to the output terminal of the analog circuit, and the output terminal of the first control circuit is connected to the control terminal of the first selection circuit, the first control circuit is used to control the connection between the third input terminal and the first output terminal of the first selection circuit when power is applied, the fourth input terminal and the second output terminal of the first selection circuit are connected, and the analog circuit is connected to the first reference signal source through the first selection circuit. The first control circuit is used to control the connection between the first input terminal and the first output terminal of the first selection circuit, and the second input terminal and the second output terminal of the first selection circuit are connected. The analog circuit is used to receive the analog input signal through the first selection circuit.

2. The analog self-calibration circuit according to claim 1, characterized in that, The first selection circuit includes a double-pole double-throw switch and a first relay. The first and second input terminals of the double-pole double-throw switch are respectively connected to the external device. The third and fourth input terminals of the double-pole double-throw switch are respectively connected to the first reference signal source. The first relay is connected to the output terminal of the first control circuit. The first relay and the double-pole double-throw switch are spaced apart.

3. The analog self-calibration circuit according to claim 2, characterized in that, The first control circuit is used to control the first relay to work when power is applied. The third input terminal and the first output terminal of the double-pole double-throw switch are connected, and the fourth input terminal and the second output terminal of the double-pole double-throw switch are connected. The first control circuit is used to control the first relay to stop working. The first input terminal and the first output terminal of the double-pole double-throw switch are connected, and the second input terminal and the second output terminal of the double-pole double-throw switch are connected.

4. The analog self-calibration circuit according to claim 2, characterized in that, The first control circuit includes a controller, a first resistor, a second resistor, a first switching transistor, and a first diode. The input terminal of the controller is connected to the output terminal of the analog circuit and is used to calibrate the analog input signal based on the first reference signal from the first reference signal source. The output terminal of the controller is connected to the control terminal of the first switching transistor through the first resistor. The second resistor is connected between the control terminal and the first terminal of the first switching transistor. The first terminal of the first switching transistor is grounded. The second terminal of the first switching transistor is connected to the first terminal of the first relay. The second terminal of the first switching transistor is connected to the second terminal of the first relay through the first diode. The second terminal of the first relay receives a first reference voltage.

5. The analog self-calibration circuit according to claim 4, characterized in that, The controller is used to control the first switch to be turned on, so that the first relay is activated; the controller is also used to control the first switch to be turned off, so that the first relay is deactivated.

6. The analog self-calibration circuit according to claim 4, characterized in that, The analog self-calibration circuit further includes at least one second selection circuit and at least one second control circuit. The second selection circuit is connected between the first selection circuit and the external device, and the second control circuit is connected to the controller and the control terminal of the second selection circuit.

7. The analog self-calibration circuit according to claim 6, characterized in that, The first and second input terminals of the second selection circuit are respectively connected to the external device, the third and fourth input terminals of the second selection circuit are respectively connected to the second reference signal source, the first output terminal of the second selection circuit is connected to the first input terminal of the first selection circuit, the second output terminal of the second selection circuit is connected to the second input terminal of the first selection circuit, and the output terminal of the second control circuit is connected to the control terminal of the second selection circuit.

8. The analog self-calibration circuit according to claim 7, characterized in that, The second control circuit includes a third resistor, a fourth resistor, a second switch, and a second diode. The output terminal of the controller is connected to the control terminal of the second switch through the third resistor. The fourth resistor is connected between the control terminal and the first terminal of the second switch. The first terminal of the second switch is grounded. The second terminal of the second switch is connected to the first terminal of the second relay of the second selection circuit. The second terminal of the second switch is connected to the second terminal of the second relay through the second diode. The second terminal of the second relay receives the first reference voltage.

9. The analog self-calibration circuit according to claim 4, characterized in that, The analog self-calibration circuit further includes multiple second selection circuits and multiple second control circuits. The multiple second selection circuits are sequentially connected between the first selection circuit and the external device. The multiple second control circuits are connected to the controller, and each second control circuit is connected to the control terminal of the corresponding second selection circuit.

10. An analog self-calibration device, characterized in that, Includes the analog self-calibration circuit as described in any one of claims 1-9.

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