Three-operational-amplifier voltage comparison circuit device

Abstract

The utility model relates to a three-operational-amplifier voltage comparison circuit device, which belongs to the technical field of teaching aid circuit design, and is characterized in that the output end of an interference switch is connected with one input end of an adder, and the other input end of the adder is used for accessing noise-free signals; the output end of the summator is respectively connected with one input end of a hysteresis comparator and one input end of a non-hysteresis comparator, the other input end of the hysteresis comparator is provided with a hysteresis adjusting structure, the other input end of the non-hysteresis comparator is provided with a comparator threshold adjusting structure, the output end of the hysteresis comparator is connected to a test point AIN3, and the output end of the non-hysteresis comparator is connected to the test point AIN4. The output end of the hysteresis-free comparator is connected to the test point AIN2, the test point AIN1 is connected to the output end of the adder, each test point AIN3 is used for being connected with a waveform observation instrument, the adder is used for mixing and outputting input noise-free signals and noise signals, and the hysteresis comparator and the hysteresis-free comparator are used for comparing and demonstrating the influence of hysteresis on the signals. And the hysteretic prominent demonstration is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to teaching aid circuit design technical field relates to a three operational amplifier voltage comparison circuit device. BACKGROUND

[0002] Voltage comparison circuit is widely used in industrial control, household appliances, communication and automotive electronics, the core use is to compare the input voltage with the set reference voltage, output high and low level signal, for realizing threshold detection, overvoltage / undervoltage protection, temperature control, battery management, waveform shaping and zero-crossing detection function. The implementation structure of the current mainstream voltage comparison circuit has three kinds: (1) single limit comparator: the most basic form, input voltage is higher (or lower) than the reference voltage and flips the output, simple structure but poor anti-noise; (2) hysteresis comparator (Schmitt trigger): two different threshold values are introduced through positive feedback, forming a hysteresis, suppressing input jitter, improving anti-interference ability; (3) window comparator: composed of two comparators, can monitor whether the input falls between high and low reference voltage, used for range detection. The working process of voltage comparison circuit is to connect the input measured signal to one end of the comparator, and the other end is connected to the precise reference voltage, when the input exceeds the set threshold, the output stage jumps to high or low level rapidly, driving the subsequent logic, relay, MCU or protection circuit to execute corresponding action.

[0003] In industrial field, voltage comparison circuit is often used as threshold discriminator device to realize the upper and lower limit monitoring of temperature, current and voltage and other key parameters. However, the millivolt level periodic ripple and random pulse introduced by line coupling, relay switching and high-frequency switching power supply, easy to make voltage comparison circuit produce multiple back and forth flip near the threshold, that is, "critical jitter" phenomenon, leading to the misoperation of subsequent logic or protection circuit. In order to suppress this kind of "critical jitter" phenomenon, positive feedback is generally introduced in the comparison loop in engineering design, which constitutes a Schmitt comparator with hysteresis characteristic, so that the rising trigger voltage and the falling trigger voltage form a hundred millivolt difference ΔV. However, in the traditional textbook, the design method of the positive feedback network introduced in the comparison loop is ignored, which leads students and even beginners to only master the single threshold comparison idea, and it is difficult to directly deal with complex electromagnetic environment. In addition, in the teaching demonstration link, since the laboratory power output is pure and the load is stable, there is lack of controllable and visible disturbance source, and learners can not directly observe the multiple flip phenomenon of the non-hysteresis scheme, and can not verify the improvement of the hysteresis amount on the system reliability, thereby limiting the popularization and deepening of the technology. Therefore, how to directly and efficiently demonstrate the hysteresis principle in voltage comparison circuit has become one of the technical problems to be solved. UTILITY MODEL CONTENTS

[0004] To address the problems existing in the above-mentioned traditional technologies, this utility model proposes a three-operation amplifier voltage comparator circuit device, which can intuitively and efficiently demonstrate the hysteresis principle in voltage comparator circuits.

[0005] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions:

[0006] A three-op-amp voltage comparator circuit device is provided, including an interference switch, an adder, a comparator with hysteresis, a comparator without hysteresis, test point AIN1, test point AIN2 and test point AIN3;

[0007] The input terminal of the interference switch is used to receive a noise signal. The output terminal of the interference switch is connected to one input terminal of the adder. The other input terminal of the adder is used to receive a noise-free signal. The output terminal of the adder is connected to one input terminal of a hysteresis comparator and one input terminal of a hysteresis-free comparator. The other input terminal of the hysteresis comparator has a hysteresis adjustment structure, and the other input terminal of the hysteresis-free comparator has a comparator threshold adjustment structure. The output terminal of the hysteresis comparator is connected to test point AIN3, the output terminal of the hysteresis-free comparator is connected to test point AIN2, and test point AIN1 is connected to the output terminal of the adder. Test points AIN1, AIN2, and AIN3 are used to connect to waveform observation instruments. The adder is used to mix the input noise-free signal and the noise signal for output. The hysteresis comparator and the hysteresis-free comparator are used to compare and demonstrate the effect of hysteresis on the signal.

[0008] In one embodiment, the adder includes an operational amplifier, resistors R1, R3, R5, R8, and R9. One end of resistor R5 is used to receive a noise-free signal, and the other end of resistor R5 is connected to one end of resistor R1 and the inverting input of the operational amplifier. One end of resistor R8 is connected to the output of an interference switch, and the other end of resistor R8 is connected to the inverting input of the operational amplifier. The non-inverting input of the operational amplifier is grounded through resistor R9. The other end of resistor R1 is connected to the output of the operational amplifier through resistor R3. The output of the operational amplifier is connected to test point AIN1, one input of a comparator with hysteresis, and one input of a comparator without hysteresis.

[0009] In one embodiment, resistor R3 is a variable resistor.

[0010] In one of the embodiments, the hysteresis-free comparator comprises a comparator LM393, a resistor R6, a resistor R7 and a potentiometer R14, one end of the resistor R6 is connected to the output of the adder, the other end of the resistor R6 is connected to the inverting input of the comparator LM393, the non-inverting input of the comparator LM393 is connected to the power supply through the potentiometer R14, the output of the comparator LM393 is connected to the test point AIN2 and one end of the resistor R7, the other end of the resistor R7 is connected to the power supply of the comparator LM393, and the potentiometer R14 is used as a comparator threshold adjustment structure and is used to adjust the comparator threshold of the hysteresis-free comparator; the potentiometer R14 adopts a variable resistor structure.

[0011] In one of the embodiments, the hysteresis-free comparator comprises a comparator LM393, a resistor R6, a resistor R7 and a potentiometer R14, one end of the resistor R6 is connected to the output of the adder, the other end of the resistor R6 is connected to the inverting input of the comparator LM393, the non-inverting input of the comparator LM393 is connected to the power supply through the potentiometer R14, the output of the comparator LM393 is connected to the test point AIN2 and one end of the resistor R7, the other end of the resistor R7 is connected to the power supply of the comparator LM393, and the potentiometer R14 is used as a comparator threshold adjustment structure and is used to adjust the comparator threshold of the hysteresis-free comparator; the potentiometer R14 adopts a variable resistor structure.

[0012] The other end of the resistor R15 is connected to the non-inverting input of the comparator LM393 through the potentiometer R12, and the potentiometer R12 is used as a hysteresis adjustment structure and is used to adjust the proportion of the hysteresis of the hysteresis comparator; the potentiometer R12 adopts a variable resistor structure.

[0013] In one of the embodiments, the three operational amplifier voltage comparison circuit device further comprises two signal source terminals, one of the signal source terminals is used to input a noise-free signal to the adder, and the other of the signal source terminals is used to input a noise signal to the interference switch.

[0014] In one of the embodiments, the three operational amplifier voltage comparison circuit device further comprises an oscilloscope connection port, each connection terminal of the oscilloscope connection port is connected to the test point AIN1, the test point AIN2 and the test point AIN3 respectively, and the oscilloscope connection port is used to connect an oscilloscope.

[0015] In one of the embodiments, the three operational amplifier voltage comparison circuit device further comprises a board-mounted power supply interface, the board-mounted power supply interface is connected to the power supply terminals of the adder, the hysteresis comparator and the hysteresis-free comparator respectively, and the board-mounted power supply interface is used to connect an external power supply.

[0016] One of the technical solutions has the following advantages and beneficial effects:

[0017] The three operational amplifier voltage comparison circuit device compares one comparator with hysteresis and one comparator without hysteresis, mixes noise generated by another signal source by using an operational amplifier adder, simulates a signal with interference in actual engineering, and enables the signal with interference to enter two comparators, so that the effect and principle of hysteresis can be clearly compared, the technical problem that the principle of hysteresis is not easy to demonstrate is solved, and the prominent demonstration of hysteresis and the accurate controllable noise are realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a design principle block diagram of the three operational amplifier voltage comparison circuit device in an embodiment;

[0020] Figure 2 It is a physical circuit schematic diagram of the three operational amplifier voltage comparison circuit device in an embodiment;

[0021] Figure 3 It is a waveform diagram of the single limit / hysteresis comparator output (without interference) in an embodiment, which is demonstrated by an oscilloscope display;

[0022] Figure 4 It is a waveform diagram of the single limit comparator threshold adjustment (without interference) in an embodiment, which is demonstrated by an oscilloscope display;

[0023] Figure 5 It is a waveform diagram of the hysteresis comparator hysteresis voltage adjustment (without interference) in an embodiment, which is demonstrated by an oscilloscope display;

[0024] Figure 6 It is a waveform diagram of the single limit / hysteresis comparator output (with interference) in an embodiment, which is demonstrated by an oscilloscope display;

[0025] Figure 7 It is a waveform diagram of the single limit comparator threshold adjustment (with interference) in an embodiment, which is demonstrated by an oscilloscope display;

[0026] Figure 8 It is a waveform diagram of the hysteresis comparator hysteresis voltage adjustment (with interference) in an embodiment, which is demonstrated by an oscilloscope display. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the utility model clearer and more apparent, the utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and are not used to limit the utility model. Unless otherwise defined, all technical and scientific terms used in the utility model are the same as the meanings commonly understood by the skilled person in the technical field to which the utility model belongs. The terms used in the specification of the utility model are only for the purpose of describing the specific examples and are not intended to limit the utility model.

[0028] It should be noted that the term "example" in the utility model means that the specific features, structures or characteristics described in combination with the examples can be included in at least one example of the utility model. The phrase is shown at various places in the specification and does not necessarily refer to the same example, nor is it an independent or alternative example that is not mutually exclusive with other examples. Those skilled in the art can understand that the examples described in the utility model can be combined with other examples. The term "and / or" used in the specification of the utility model means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0029] The embodiments of the utility model will be described in detail below in combination with the drawings in the utility model examples.

[0030] In one example, as shown in Figure 1 and Figure 2 , a three operational amplifier voltage comparison circuit device is provided, including an interference switch SW, an adder, a hysteresis comparator, a non-hysteresis comparator, a test point AIN1, a test point AIN2 and a test point AIN3. The input end of the interference switch SW is used to access a noise signal, the output end of the interference switch SW is connected to one input end of the adder, the other input end of the adder is used to access a noise-free signal, the output end of the adder is connected to one input end of the hysteresis comparator and the non-hysteresis comparator respectively, the other input end of the hysteresis comparator is provided with a hysteresis adjustment structure, the other input end of the non-hysteresis comparator is provided with a comparator threshold adjustment structure, the output end of the hysteresis comparator is connected to the test point AIN3, the output end of the non-hysteresis comparator is connected to the test point AIN2, the test point AIN1 is connected to the output end of the adder, the test point AIN1, the test point AIN2 and the test point AIN3 are respectively used to connect to a waveform observation instrument, the adder is used to mix and output the input noise-free signal and noise signal, the hysteresis comparator and the non-hysteresis comparator are used to demonstrate the influence of hysteresis on the signal.

[0031] It can be understood that, as Figure 1As shown, the three operational amplifier voltage comparator circuit includes an adder, a hysteresis-free comparator, and a hysteresis-based comparator. A clean, noise-free signal and a noise signal controlled by an interference switch SW enter the adder, generating a mixed-noise signal. The mixed-noise signal then enters the hysteresis-based comparator and the hysteresis-free comparator, respectively. The outputs of the two comparators can be observed with an oscilloscope, clearly comparing the effect of the hysteresis. All circuit components are integrated on the same circuit board.

[0032] In one embodiment, such as Figure 2 As shown, the adder includes an operational amplifier, resistors R1, R3, R5, R8, and R9. One end of resistor R5 is used to input a noise-free signal, and the other end of resistor R5 is connected to one end of resistor R1 and the inverting input of the operational amplifier. One end of resistor R8 is connected to the output of the interference switch SW, and the other end of resistor R8 is connected to the inverting input of the operational amplifier. The non-inverting input of the operational amplifier is grounded through resistor R9. The other end of resistor R1 is connected to the output of the operational amplifier through resistor R3. The output of the operational amplifier is connected to test point AIN1, one input of the comparator with hysteresis, and one input of the comparator without hysteresis.

[0033] It is understood that the adder in this embodiment can be designed using an operational amplifier NE5532 in conjunction with its peripheral circuit components, and an adder with a ratio of -1 can be implemented with resistors R1, R5 and R8 to form an inverting adder with a ratio of -1, so as to more flexibly cooperate with the demonstration and teaching of the circuit.

[0034] In one embodiment, such as Figure 2 As shown, furthermore, resistor R3 is a variable resistor, which can support flexible adjustment of the adder characteristics according to the needs of demonstration teaching, and improve the control flexibility of the demonstration.

[0035] In one embodiment, such as Figure 2 As shown, the hysteresis-free comparator includes a comparator LM393, resistors R6 and R7, and a potentiometer R14. One end of resistor R6 is connected to the output of the adder, and the other end of resistor R6 is connected to the inverting input of comparator LM393. The non-inverting input of comparator LM393 is used to connect to the power supply through potentiometer R14. The output of comparator LM393 is connected to test point AIN2 and one end of resistor R7. The other end of resistor R7 and the power supply terminal of comparator LM393 are respectively used to connect to the power supply. Potentiometer R14 serves as the comparator threshold adjustment structure and is used to adjust the comparator threshold of the hysteresis-free comparator; potentiometer R14 adopts a variable resistor structure.

[0036] It can be understood that in the embodiment, the non-hysteresis comparator can be composed of a comparator LM393 and its peripheral circuit, and a potentiometer (such as R14) can be used to adjust the threshold of the comparator. It can be shown that the adjustment flexibility of the non-hysteresis comparator is greatly improved.

[0037] In one embodiment, as shown in Figure 2 , the hysteresis comparator includes a comparator LM393, a resistor R10, a resistor R11, a potentiometer R12, a resistor R13 and a resistor R15. One end of the resistor R11 is connected to the output end of the adder, and the other end of the resistor R11 is connected to the inverting input end of the comparator LM393. The non-inverting input end of the comparator LM393 is used to be grounded through the resistor R13. The output end of the comparator LM393 is connected to the test point AIN3, one end of the resistor R10 and one end of the resistor R15. The other end of the resistor R10 and the power supply end of the comparator LM393 are respectively used to be connected to the power supply. The other end of the resistor R15 is connected to the non-inverting input end of the comparator LM393 through the potentiometer R12. The potentiometer R12 is used as a hysteresis adjustment structure and is used to adjust the proportion of the hysteresis of the hysteresis comparator. The potentiometer R12 adopts a variable resistor structure.

[0038] It can be understood that in the embodiment, the hysteresis comparator can be composed of a comparator LM393 and its peripheral circuit, and a potentiometer (such as R12) can be used to adjust the proportion of the hysteresis, which can cope with different amplitudes of noise. The hysteresis comparator can form a hysteresis loop through the potentiometer R12, the resistor R13 and the resistor R15, and the proportion of the hysteresis can be directly adjusted through the potentiometer R12, so that the flexibility of the demonstration is greatly improved. The outputs of the above two comparators (connected to the oscilloscope through the test points AIN3 and AIN2 respectively) can be observed simultaneously to observe the clean square wave and the square wave with burr, thereby highlighting the advantages of hysteresis.

[0039] In one embodiment, the above-mentioned three operational amplifier voltage comparison circuit device further includes two signal source terminals (such as Figure 2 signal sources S1 and S2), one signal source terminal is used to connect a noise-free signal to the adder, and one signal source terminal is used to connect a noise signal to the interference switch SW, thereby facilitating the quick connection of external signal sources for demonstration teaching.

[0040] In one embodiment, as shown in Figure 2 , the above-mentioned three operational amplifier voltage comparison circuit device further includes an oscilloscope connection port, and each connection terminal of the oscilloscope connection port is connected to the test point AIN1, the test point AIN2 and the test point AIN3 respectively. The oscilloscope connection port is used to connect the oscilloscope, thereby facilitating the quick connection of external oscilloscopes to visually display the signal waveforms related to the demonstration.

[0041] In one embodiment, as shown in Figure 2 the three operational amplifier voltage comparison circuit device described above further comprises a board-mounted power supply interface, which is connected to the power supply terminals of the adder, the hysteresis comparator and the non-hysteresis comparator respectively, and is used to connect an external power supply. The external power supply can be a power supply suitable for the power supply needs of the circuit, such as but not limited to a 5V power supply.

[0042] In this way, in the design described above, the effect of the threshold on the noise (i.e. no effect) can be demonstrated by adjusting the potentiometer R14, and the usefulness of hysteresis can be highlighted by adjusting the potentiometer R12, and when the noise increases, the resistance of the potentiometer R12 needs to be reduced to increase the hysteresis ratio to cope with large interference signals. The existence of the two comparators at the same time avoids the need to switch the comparison operation, and the comparison operation can be directly observed through the double trace display of a waveform observation instrument such as an oscilloscope.

[0043] The three operational amplifier voltage comparison circuit device described above compares one hysteresis comparator with one non-hysteresis comparator, mixes the noise generated by another signal source with the adder of the operational amplifier, simulates the signal with interference in actual engineering, and makes the signal with interference enter the two comparators, so that the effect and principle of hysteresis can be clearly compared, the technical problem that the principle of hysteresis is not easy to demonstrate is solved, and the prominent demonstration of hysteresis and the accurate controllability of noise are realized.

[0044] In some embodiments, some demonstration application examples of the three operational amplifier voltage comparison circuit device described above are also provided to further demonstrate its effect:

[0045] The three operational amplifier voltage comparison circuit device described above is equipped with four Dupont line adapter interfaces for connecting the circuit board to the pocket experiment platform, input and output configuration (recommended) including power supply configuration can use 12V, 300mA positive power supply, -12V, <330mA negative power supply, input configuration such as signal S1 with a frequency of 10KHz, a peak-to-peak value of 300mVpp, a direct current of 0mV and a phase of 0deg, signal S2 with a frequency of 1KHz, a peak-to-peak value of 1kmVpp, a direct current of 0mV and a phase of 0deg. The output configuration is, for example, channels 1 to 3 of an oscilloscope.

[0046] Demonstration instructions:

[0047] Single limit / hysteresis comparator output (in the absence of interference): In the absence of interference, the input and output waveforms observed by the oscilloscope are as shown in Figure 3 The functions of the single limit comparator and the hysteresis comparator can be demonstrated, and it can be seen that the flip of the hysteresis comparator lags behind compared to the single limit comparator, which is also the origin of the name of the hysteresis comparator.

[0048] Monotonic comparator threshold adjustment (no interference case): adjust the potentiometer R3 to change the threshold of the monotonic comparator, and observe its effect on the output waveform of the monotonic comparator (as shown in Figure 4 ).

[0049] Hysteresis comparator hysteresis voltage adjustment (no interference case): adjust the potentiometer R14 to change the upper and lower thresholds and hysteresis voltage of the hysteresis comparator, and observe its effect on the output waveform of the hysteresis comparator (as shown in Figure 5 ).

[0050] Monotonic / hysteresis comparator output (with interference): under the condition of interference, observe the input and output waveforms as shown in Figure 6 , and demonstrate the functions of the monotonic comparator and the hysteresis comparator. It can be seen that after adding interference, the monotonic comparator has multiple false flips, while the hysteresis comparator has strong anti-interference ability and does not have false flips.

[0051] Monotonic comparator threshold adjustment (with interference): adjust the potentiometer R3 to change the threshold of the monotonic comparator, and observe its effect on the output waveform of the monotonic comparator (as shown in Figure 7 ).

[0052] Hysteresis comparator hysteresis voltage adjustment (with interference): adjust the potentiometer R14 to change the hysteresis voltage of the hysteresis comparator, and observe its effect on the output waveform of the hysteresis comparator (as shown in Figure 8 ). It can be seen that when the hysteresis voltage of the hysteresis comparator decreases, the anti-interference effect becomes worse, and the output waveform approaches that of the monotonic comparator.

[0053] In the above waveforms Figures 3 to 8 , the yellow waveform is the output of channel 1 of the oscilloscope, the blue waveform is the output of channel 2 of the oscilloscope, and the purple waveform is the output of channel 3 of the oscilloscope. Among them, the horizontal axis of each waveform graph is time (microseconds), and the vertical axis is signal amplitude (volts).

[0054] The circuit design of the three operational amplifier voltage comparison circuit device described above fully demonstrates the advantages of one board multiple use and one board full coverage. Through reasonable circuit layout and component configuration, the experimental board can complete a variety of experiments such as positive amplification, differential amplification and common mode rejection, and fully covers the teaching content of the three operational amplifier subtraction circuit. At the same time, the use of the experimental board is relatively simple. Through the setting of jumpers and switches, the working mode of the circuit can be easily switched, avoiding errors caused by frequent disassembly and assembly of the circuit, and improving the accuracy and reliability of the experiment. This design fully overcomes the shortcomings of the traditional three operational amplifier subtractor experiment, and provides great convenience for teaching and experiment.

[0055] It should be noted that in the specific circuit diagrams of the above-mentioned circuit parts, if the pins in different circuit diagrams are marked with the same reference numerals, it means that the pins with the same reference numerals are connected.

[0056] The technical features of the above embodiments can be combined in any manner, and for the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present disclosure.

[0057] The above embodiments only express several implementation manners of the present application, the description is relatively specific and detailed, but it should not be understood as a limitation on the protection scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

1. A three operational amplifier voltage comparison circuit arrangement characterized by, The interference switch, the adder, the hysteresis comparator, the non-hysteresis comparator, the test point AIN1, the test point AIN2 and the test point AIN3; The input end of the interference switch is used for connecting the noise signal, the output end of the interference switch is connected to one input end of the adder, the other input end of the adder is used for connecting the non-noise signal, the output end of the adder is connected to one input end of the hysteresis comparator and one input end of the non-hysteresis comparator respectively, the other input end of the hysteresis comparator is provided with the hysteresis adjusting structure, the other input end of the non-hysteresis comparator is provided with the comparator threshold adjusting structure, the output end of the hysteresis comparator is connected to the test point AIN3, the output end of the non-hysteresis comparator is connected to the test point AIN2, the test point AIN1 is connected to the output end of the adder, and the test point AIN1, the test point AIN2 and the test point AIN3 are used for connecting the waveform observation instrument respectively, and the adder is used for mixing and outputting the input non-noise signal and the noise signal, and the hysteresis comparator and the non-hysteresis comparator are used for comparing and demonstrating the influence of hysteresis on the signal.

2. The tri- op amp voltage comparator circuit arrangement of claim 1, wherein, The adder comprises an operational amplifier, a resistor R1, a resistor R3, a resistor R5, a resistor R8 and a resistor R9, one end of the resistor R5 is used for connecting the non-noise signal, the other end of the resistor R5 is connected to one end of the resistor R1 and the inverting input end of the operational amplifier respectively, one end of the resistor R8 is connected to the output end of the interference switch, the other end of the resistor R8 is connected to the inverting input end of the operational amplifier, the non-inverting input end of the operational amplifier is grounded through the resistor R9, the other end of the resistor R1 is connected to the output end of the operational amplifier through the resistor R3, and the output end of the operational amplifier is connected to the test point AIN1, one input end of the hysteresis comparator and one input end of the non-hysteresis comparator respectively.

3. The tri- op amp voltage comparator circuit arrangement of claim 2, wherein, The resistor R3 is a variable resistor.

4. The tri- op amp voltage comparator circuit arrangement according to any one of claims 1 to 3, characterized in that, The non-hysteresis comparator comprises a comparator LM393, a resistor R6, a resistor R7 and a potentiometer R14, one end of the resistor R6 is connected to the output end of the adder, the other end of the resistor R6 is connected to the inverting input end of the comparator LM393, the non-inverting input end of the comparator LM393 is used for being connected to the power supply through the potentiometer R14, the output end of the comparator LM393 is connected to the test point AIN2 and one end of the resistor R7, the other end of the resistor R7 and the power supply end of the comparator LM393 are used for being connected to the power supply respectively, and the potentiometer R14 is used as the comparator threshold adjusting structure and is used for adjusting the comparator threshold of the non-hysteresis comparator; the potentiometer R14 adopts a variable resistor structure.

5. The tri- op amp voltage comparator circuit arrangement according to any one of claims 1 to 3, characterized in that The hysteresis comparator comprises a comparator LM393, a resistor R10, a resistor R11, a potentiometer R12, a resistor R13 and a resistor R15, one end of the resistor R11 is connected to the output end of the adder, the other end of the resistor R11 is connected to the inverting input end of the comparator LM393, the non-inverting input end of the comparator LM393 is used for being grounded through the resistor R13, the output end of the comparator LM393 is connected to the test point AIN3, one end of the resistor R10 and one end of the resistor R15, and the other end of the resistor R10 and the power supply end of the comparator LM393 are used for being connected to the power supply respectively; The other end of the resistor R15 is connected to the non-inverting input terminal of the comparator LM393 through the potentiometer R12, and the potentiometer R12 is used as a hysteresis adjustment structure and is used for adjusting the proportion of the hysteresis comparator; the potentiometer R12 adopts a variable resistance structure.

6. The tri- op amp voltage comparator circuit arrangement of claim 1, wherein, Two signal source terminals are further included, one of which is used for inputting a noise-free signal to the adder, and the other of which is used for inputting a noise signal to the interference switch.

7. The tri- op amp voltage comparator circuit arrangement of claim 1, wherein, An oscilloscope connection port is further included, and each wiring terminal of the oscilloscope connection port is connected to the test point AIN1, the test point AIN2 and the test point AIN3 respectively, and the oscilloscope connection port is used for connecting an oscilloscope.

8. The tri- op amp voltage comparator circuit arrangement of claim 1, wherein, A board-mounted power supply interface is further included, and the board-mounted power supply interface is connected to the power supply terminals of the adder, the hysteresis comparator and the non-hysteresis comparator respectively, and the board-mounted power supply interface is used for connecting an external power supply.

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