Multifunctional analog quantity signal input circuit
By designing a multifunctional amplification unit and a control switching switch module in the analog input signal circuit, the problems of low accuracy and cumbersome operation of analog input signal conversion in the prior art are solved, and high-precision adaptation and simplified operation of different types of signals are achieved.
Patent Information
- Application Number
- CN202421388045.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-06-17
AI Technical Summary
When the existing analog input signal circuit converts the analog current signal to a voltage signal, the voltage is too low, resulting in a reduction in conversion accuracy, and the process of controlling the access and disconnection of the sampling resistor is cumbersome and requires manual operation.
A multifunctional analog signal input circuit is designed, a first amplification unit and a second amplification unit are used, and a control switching switch module is set in the first amplification unit, and the gain value of the amplification unit is controlled by a controller to adapt to different types of analog input signals.
Adaptive processing of analog current signals and voltage signals is realized, conversion accuracy is improved, and circuit operation is simplified, avoiding the cumbersome process of manually switching switches.
Smart Images
Figure CN222827231U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of analog signal input circuits, and in particular to a multifunctional analog signal input circuit. Background Art
[0002] There are many types of analog input signals, including analog voltage signals or analog current signals. The analog input signal circuit is used to process analog voltage signals or analog current signals so that the analog signals can be normally input into the digital-to-analog conversion module in the controller to realize analog-to-digital conversion.
[0003] The existing analog input signal includes a sampling resistor and an operational amplifier unit. The sampling resistor can convert the analog current signal into a voltage signal, which is then processed by the operational amplifier unit and input into the analog-to-digital conversion module. However, during use, the voltage signal is too low after being divided by the sampling resistor and then input into the subsequent module through the operational amplifier unit, which reduces the conversion accuracy.
[0004] In the prior art, the connection and disconnection of the sampling resistor are controlled to ensure the conversion accuracy of the voltage signal. However, the overall use is still relatively cumbersome, and the connection or disconnection of the sampling resistor needs to be controlled by manually switching the switch. Utility Model Content
[0005] In order to be able to more conveniently adapt to different types of analog input signals and ensure conversion accuracy, the present application provides a multifunctional analog signal input circuit.
[0006] The present application provides a multifunctional analog signal input circuit adopting the following technical solution:
[0007] A multifunctional analog signal input circuit includes a first amplifying unit and a second amplifying unit, and an input signal is input to a subsequent circuit through the first amplifying unit and the second amplifying unit in sequence; a control switching switch module is provided in the first amplifying unit, and a control end of the control switching switch module is electrically connected to an output end of the controller, and the control switching switch module is used to switch the gain value of the amplifying unit.
[0008] By adopting the above technical solution, when the input signal is a current signal, the gain value of the first amplifying unit can be adapted to the current signal through the controller; when the input signal is a voltage signal, the gain value of the first amplifying unit can be adapted to the voltage signal through the controller, so that according to the category of the analog input signal, the gain value suitable for the input signal can be selected to improve the conversion accuracy.
[0009] Preferably, the first amplifying unit includes a first operational amplifier U2 and a feedback resistor R8, the input signal terminal IN1- is electrically connected to the inverting input terminal of the first operational amplifier U2 through a sampling resistor and a resistor R6, the input signal terminal IN1+ is electrically connected to the inverting input terminal of the first operational amplifier U2 through a resistor R7, the non-inverting input terminal of the first operational amplifier U2 is grounded, the inverting input terminal of the first operational amplifier U2 is also electrically connected to the output terminal of the first operational amplifier U2 through the feedback resistor R8, and the output terminal of the first operational amplifier U2 is electrically connected to the input terminal of the second amplifying unit; the first connection terminal of the control switching switch module is electrically connected to the connection point between the sampling resistor and the resistor R6, the second connection terminal of the control switching switch module is electrically connected to the input signal terminal IN1+, and the control switching switch module is used to control the first connection terminal and the second connection terminal to be turned on or off.
[0010] By adopting the above technical solution, when the analog input signal is a current signal, the first connection terminal and the second connection terminal are cut off by controlling the switching switch module; at this time, the current signal is input from the input signal terminal IN1-, and is converted into a voltage signal through the sampling resistor, and the gain value of the first amplifier unit is related to the resistance value of the resistor R6 and the feedback resistor R8. When the analog input signal is a voltage signal, the first connection terminal and the second connection terminal are turned on by controlling the switching switch module; at this time, the voltage signal is input from the input signal terminal IN1+, and the gain value of the first amplifier unit is related to the resistance value of the resistor R6, the resistor R7 and the feedback resistor R8. Through the above content, the switching of the gain multiple of the first amplifier unit can be realized, so that the analog current signal and the analog voltage signal can be more conveniently adapted.
[0011] Preferably, the control switching switch module includes an optocoupler relay U1, pin 1 of the optocoupler relay U1 is electrically connected to the output end of the controller, pin 2 of the optocoupler relay U1 is grounded, pin 3 of the optocoupler relay U1 is electrically connected to the connection point between the sampling resistor and the resistor R6, and pin 4 of the optocoupler relay U1 is electrically connected to the input signal terminal IN1+.
[0012] By adopting the above technical solution, when the controller outputs a high level, the optocoupler relay U1 is in the on state, and when the controller outputs a low level, the optocoupler relay U1 is in the off state. The optocoupler relay U1 can achieve complete electrical isolation between the input and output ends, has a high insulation resistance, and can effectively block the electrical connection between circuits or systems.
[0013] Preferably, the output end of the controller is electrically connected to pin 1 of the optocoupler relay U1 through a resistor R1.
[0014] By adopting the above technical solution, the resistor R1 is used to enable the voltage value output by the controller to be input to the photocoupler relay more safely and stably.
[0015] Preferably, the second amplifying unit includes a second operational amplifier U3 and a feedback resistor R10, the output end of the first amplifying unit is electrically connected to the inverting input end of the second operational amplifier U2 through a resistor R9, and the non-inverting input end of the second operational amplifier U2 is grounded; one end of the feedback resistor R10 is electrically connected to the inverting input end of the second operational amplifier U2, the other end of the feedback resistor R10 is electrically connected to the output end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is electrically connected to the post-stage circuit.
[0016] By adopting the above technical solution and setting a second amplifying unit, the signal processed by the first amplifying unit can be further amplified, and at the same time, the output signal of the overall circuit can be made consistent in phase with the analog input signal, so as to facilitate subsequent processing by the analog-to-digital conversion module.
[0017] Preferably, the second amplifying unit further includes a bias module, which includes a resistor R11 and a reference voltage output terminal VREF-, and the reference voltage output terminal VREF- is electrically connected to the inverting input terminal of the second operational amplifier U2 through the resistor R11.
[0018] By adopting the above technical solution, the inverting input terminal of the second operational amplifier U2 is biased so that the voltage received by the controller is within a reasonable range.
[0019] Preferably, the second amplifying unit further includes a filter capacitor C1, one end of the filter capacitor C1 is electrically connected to the inverting input end of the second operational amplifier U2, and the other end of the filter capacitor C1 is electrically connected to the output end of the second operational amplifier U2.
[0020] By adopting the above technical solution, the filter capacitor C1 plays a role of filtering and stabilizing voltage, which can improve the stability of the output signal of the second amplifying unit.
[0021] Preferably, the second operational amplifier U3 is electrically connected to the subsequent circuit via a resistor R10.
[0022] By adopting the above technical solution, the resistor R10 is used for protection, which helps to prevent the components in the subsequent circuit from being damaged due to excessive current.
[0023] In summary, the present application includes at least one of the following beneficial technical effects:
[0024] The analog input signal is processed by the first amplification unit and the second amplification unit in turn, and then can enter the analog-to-digital conversion module of the subsequent stage. According to the type of different input signals, the controller controls the conduction and cutoff of the optical coupling relay, thereby changing the gain multiple of the first amplification unit, thereby realizing adaptive processing of the voltage input signal and the current input signal to ensure the conversion accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a principle block diagram of an embodiment of the present application;
[0026] Figure 2 is a circuit diagram of a first amplifying unit in an embodiment of the present application;
[0027] Figure 3 is a circuit diagram of the second amplifying unit in an embodiment of the present application.
[0028] Figure numerals: 1, first amplifying unit; 11, control switching switch module; 2, second amplifying unit; 21, bias module. DETAILED DESCRIPTION
[0029] The following is combined with Figure 1-3 This application is described in further detail.
[0030] The embodiment of the present application discloses a multifunctional analog signal input circuit.
[0031] Reference Figure 1 A multifunctional analog signal input circuit includes a first amplifying unit 1 and a second amplifying unit 2, and the input signal is sequentially input to the subsequent circuit through the first amplifying unit 1 and the second amplifying unit 2. A control switching switch module 11 is provided in the first amplifying unit 1. And the control end of the control switching switch module 11 is electrically connected to the controller, and the control switching switch module 11 is used to switch the gain value of the amplifying unit. When the input signal is a current signal, the controller outputs a first control signal to the control end of the control switching switch module 11, so that the gain value of the first amplifying unit 1 can be adapted to the current signal; when the input signal is a voltage signal, the controller outputs a second control signal to the control end of the control switching switch module 11, so that the gain value of the first amplifying unit 1 can be adapted to the voltage signal.
[0032] Reference Figure 2, the first amplification unit 1 also includes a first operational amplifier U2, and a feedback resistor R8. The input signal terminal IN1- is electrically connected to the inverting input terminal of the first operational amplifier U2 through resistors R2 and R6 in turn, and resistors R3 are connected in parallel at both ends of the resistor R2. Resistors R2 and R3 form a sampling resistor, and when a current signal is input from the input signal terminal IN1-, the current signal can be converted into a voltage signal through the sampling resistor. The input signal terminal IN1- is also grounded through resistors R4 and R5 in turn, and the connection point between resistors R4 and R5 is electrically connected to the non-inverting input terminal of the first operational amplifier U2. The input signal terminal IN1+ is electrically connected to the connection point between resistors R2 and R6 through the control switching switch module 11, and the input signal terminal IN1+ is electrically connected to the inverting input terminal of the first operational amplifier U2 through resistor R7. One end of the feedback resistor R8 is electrically connected to the inverting input terminal of the first operational amplifier U2, and the other end of the feedback resistor R8 is electrically connected to the output terminal of the first operational amplifier U2. The output terminal of the first operational amplifier U2 is set as the output terminal of the first amplifying unit 1 and is electrically connected to the input terminal of the second amplifying unit 2.
[0033] The control switch module 11 includes an optocoupler relay U1 and a resistor R1, wherein the pin 1 of the optocoupler relay U1 is electrically connected to the output terminal CTO of the controller through the resistor R1, and the pin 2 of the optocoupler relay U1 is grounded. The input signal terminal IN1+ is electrically connected to the pin 3 of the optocoupler relay U1, and the pin 4 of the optocoupler relay U1 is electrically connected to the connection point between the resistor R2 and the resistor R6.
[0034] When the analog input signal is a current signal, the output terminal CRO of the controller outputs a high-level first control signal, thereby putting the optocoupler relay in a cut-off state. At this time, the current signal is input from the input signal terminal IN1-, and is converted into a voltage signal through resistors R2 and R3, and enters the first amplifier unit 1 for inverting amplification, and at this time, the gain value of the first amplifier unit 1 depends on the resistance values of resistors R6 and feedback resistors R8.
[0035] When the analog input signal is a voltage signal, the output terminal CRO of the controller outputs a low-level second control signal, thereby putting the optocoupler relay in the on state. At this time, the voltage signal is input from the input signal terminal IN1+ and enters the first amplifier unit 1 for inverting amplification. At this time, the gain value of the first amplifier unit 1 depends on the resistance values of resistor R6, resistor R7 and feedback resistor R8.
[0036] refer to Figure 2 and Figure 3, the second amplifying unit 2 includes a second operational amplifier U3, and a feedback resistor R10. The output end of the first amplifying unit 1 is electrically connected to the inverting input end of the second operational amplifier U2 through a resistor R9, and the non-inverting input end of the second operational amplifier U2 is grounded. One end of the feedback resistor R10 is electrically connected to the inverting input end of the second operational amplifier U2, and the other end of the feedback resistor R10 is electrically connected to the output end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is electrically connected to the subsequent circuit through the resistor R10. The voltage signal output by the first amplifying unit 1 can be inverted and amplified again by the second amplifying unit 2, so that the level of the voltage signal output to the subsequent module is consistent with the phase of the input signal.
[0037] In order to make the voltage received by the controller within a reasonable range, the second amplifying unit 2 further includes a bias module 21. The bias module 21 includes a resistor R11 and a reference voltage output terminal VREF-, and the reference voltage output terminal VREF- is electrically connected to the inverting input terminal of the second operational amplifier U2 through the resistor R11, so as to bias the inverting input terminal of the second operational amplifier U3.
[0038] Preferably, the second amplifying unit 2 further includes a filter capacitor C1, one end of the filter capacitor C1 is electrically connected to the inverting input end of the second operational amplifier U2, and the other end of the filter capacitor C1 is electrically connected to the output end of the second operational amplifier U2. The filter capacitor C1 plays a role of filtering and stabilizing voltage, and can improve the stability of the output signal of the second amplifying unit 2.
[0039] The implementation principle of a multifunctional analog signal input circuit in the embodiment of the present application is as follows: the input signal can enter the analog-to-digital conversion module of the subsequent stage after being processed by the first amplification unit 1 and the second amplification unit 2 in sequence. According to the type of different input signals (current signal or voltage signal), the controller controls the conduction and cutoff of the optical coupler relay: when the input signal is a current signal, the controller cuts off the optical coupler relay, and when the input signal is a voltage signal, the controller turns on the optical coupler relay, so that the gain value of the first amplification unit 1 can be adjusted according to the input signal type, thereby making this embodiment applicable to different types of analog input signals to ensure conversion accuracy.
[0040] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A multifunctional analog signal input circuit, based on a controller, characterized in that: The invention comprises a first amplifying unit (1) and a second amplifying unit (2), wherein an input signal is sequentially inputted into a subsequent circuit through the first amplifying unit (1) and the second amplifying unit (2); a control switching switch module (11) is arranged in the first amplifying unit (1), wherein a control end of the control switching switch module (11) is electrically connected to an output end of the controller, and the control switching switch module (11) is used to switch a gain value of the amplifying unit; the first amplifying unit (1) comprises a first operational amplifier U2 and a feedback resistor R8, an input signal end IN1- is electrically connected to an inverting input end of the first operational amplifier U2 through a sampling resistor and a resistor R6, an input signal end IN1+ is electrically connected to an inverting input end of the first operational amplifier U2 through a resistor R7, a non-inverting input end of the first operational amplifier U2 is grounded, and an inverting input end of the first operational amplifier U2 is also connected to an inverting input end of the first operational amplifier U2 through the feedback resistor R8. The control switch module (11) is electrically connected to the output end of the first operational amplifier U2, and the output end of the first operational amplifier U2 is electrically connected to the input end of the second amplification unit (2); the first connection end of the control switch module (11) is electrically connected to the connection point between the sampling resistor and the resistor R6, the second connection end of the control switch module (11) is electrically connected to the input signal terminal IN1+, and the control switch module (11) is used to control the first connection end and the second connection end to be turned on or off; the control switch module (11) comprises an optical coupler relay U1, pin 1 of the optical coupler relay U1 is electrically connected to the output end of the controller, pin 2 of the optical coupler relay U1 is grounded, pin 3 of the optical coupler relay U1 is electrically connected to the connection point between the sampling resistor and the resistor R6, and pin 4 of the optical coupler relay U1 is electrically connected to the input signal terminal IN1+.
2. A multifunctional analog signal input circuit according to claim 1, characterized in that: The output end of the controller is electrically connected to pin 1 of the optocoupler relay U1 through a resistor R1.
3. The multifunctional analog signal input circuit according to claim 1, characterized in that: The second amplifying unit (2) comprises a second operational amplifier U3 and a feedback resistor R10, the output end of the first amplifying unit (1) is electrically connected to the inverting input end of the second operational amplifier U2 via a resistor R9, and the non-inverting input end of the second operational amplifier U2 is grounded; one end of the feedback resistor R10 is electrically connected to the inverting input end of the second operational amplifier U2, the other end of the feedback resistor R10 is electrically connected to the output end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is electrically connected to the subsequent circuit.
4. A multifunctional analog signal input circuit according to claim 3, characterized in that: The second amplifying unit (2) further comprises a bias module (21), the bias module (21) comprising a resistor R11 and a reference voltage output terminal VREF-, the reference voltage output terminal VREF- being electrically connected to the inverting input terminal of the second operational amplifier U2 via the resistor R11.
5. A multifunctional analog signal input circuit according to claim 3 or 4, characterized in that: The second amplifying unit (2) further comprises a filter capacitor C1, one end of the filter capacitor C1 is electrically connected to the inverting input end of the second operational amplifier U2, and the other end of the filter capacitor C1 is electrically connected to the output end of the second operational amplifier U2.
6. The multifunctional analog signal input circuit according to claim 3, characterized in that: The second operational amplifier U3 is electrically connected to the subsequent circuit via a resistor R10.