Bridge signal amplification system and sensor

Abstract

The invention discloses a bridge signal amplification system and a sensor, the bridge signal amplification system comprises a gain module, a gain switching module and a main control module, the gain module is used for gaining an input signal and outputting a gain signal; the gain switching module comprises a plurality of gain units, each gain unit is selectively connected to the gain module to adjust gain multiplying power, and the gain units correspond to different gain multiplying power; and the main control module selects the gain unit accessed to the gain module and is used for selecting the gain multiplying power. By arranging the gain switching module and the main control module, intelligent selection and flexible adjustment of gain multiplying power are realized, the adaptability of the system to bridge signals with different intensities is improved, and the stability and reliability of output signals are ensured. Meanwhile, the system can automatically select the most appropriate gain multiplying power according to different signal intensities, and the problem of signal distortion or saturation caused by improper gain can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge signal amplification, and more specifically, to a bridge signal amplification system and a sensor. Background Art

[0002] The bridge signal amplifier mainly converts non-electrical quantities into electrical signals and amplifies the signals. In non-electrical measurement instruments, resistance sensors are often used to detect some non-electrical quantities, such as temperature, pressure, displacement, etc. These sensors are connected through a bridge to convert the measured non-electrical quantities into voltage or current signals, which are then further amplified by amplifiers and finally output usable electrical signals.

[0003] However, the bridge signal amplifier circuit is generally designed for the corresponding bridge and has a corresponding fixed gain. Since different sensors have different amplification factors required for the conversion of non-electrical parameters, the design of the bridge signal amplifier circuit often needs to be redesigned for a specific sensor, increasing the complexity of the circuit design.

[0004] The above shortcomings need to be improved. Summary of the invention

[0005] In order to solve or alleviate the problem in the prior art that the gain of the bridge signal amplification circuit is fixed and cannot be applied to different sensors, the present invention provides a bridge signal amplification system and a sensor.

[0006] The technical solution of the present invention is as follows:

[0007] A bridge signal amplification system, comprising:

[0008] A gain module, the gain module is used to gain an input signal and output a gain signal;

[0009] A gain switching module, wherein the gain switching module includes a plurality of gain units, each of which can be selectively connected to the gain module to adjust the gain ratio, and the gain units correspond to different gain ratios;

[0010] A main control module, wherein the main control module selects a gain unit connected to the gain module to select a gain ratio.

[0011] Furthermore, the gain switching module includes a microcontroller that is communicatively connected to the main control module, each of the gain units is a resistor with a different resistance value, and each of the gain units is respectively connected to a control pin of the microcontroller.

[0012] Furthermore, a signal enhancement module is provided at the rear stage of the gain module, and the signal enhancement module is used to filter and reduce noise and perform buffering processing on the gain signal output by the gain module, and output an enhanced signal.

[0013] Furthermore, a feedback collection module is provided at the rear stage of the signal enhancement module, and the feedback collection module is used to feed back the enhanced signal to the main control module.

[0014] Furthermore, the gain module is connected to a bias voltage zero point adjustment module, and the main control module controls the bias voltage zero point adjustment module to compensate and adjust the bias voltage of the gain module according to the feedback signal of the feedback acquisition module.

[0015] Furthermore, the main control module is connected to a control module, and the control module is used to control the bias voltage zero point adjustment module to perform zero adjustment and select the gain unit.

[0016] Furthermore, the control module includes a remote control unit, and the remote control unit is used to remotely control the bias voltage zero point adjustment module to perform zero adjustment.

[0017] Furthermore, the control module includes a local control unit, and the local control unit is used to manually control the bias voltage zero point adjustment module to perform zero adjustment or select the gain unit.

[0018] Furthermore, the main control module is connected to a status display module, and the status display module is used to display the status of the control module.

[0019] A sensor uses the above-mentioned bridge signal amplification system.

[0020] The present invention according to the above scheme has the beneficial effect that, by setting a gain switching module and a main control module, the present invention realizes intelligent selection and flexible adjustment of the gain ratio, improves the adaptability of the system to bridge signals of different strengths, and ensures the stability and reliability of the output signal. At the same time, the system can automatically select the most appropriate gain ratio according to different signal strengths, which can avoid signal distortion or saturation problems caused by improper gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a system topology diagram of the present invention;

[0023] Figure 2 This is a circuit schematic diagram of the main control module in the present invention;

[0024] Figure 3is a circuit schematic diagram of the gain module in the present invention;

[0025] Figure 4 is a circuit schematic diagram of the gain switching module in the present invention;

[0026] Figure 5 is a circuit schematic diagram of the signal enhancement module in the present invention;

[0027] Figure 6 It is a circuit schematic diagram of the feedback collection module in the present invention;

[0028] Figure 7 is a circuit schematic diagram of the bias voltage zero point adjustment module in the present invention;

[0029] Figure 8 is a circuit schematic diagram of the remote control unit module in the present invention;

[0030] Fig. 9 is a circuit schematic diagram of the local control unit in the present invention;

[0031] Fig.10 is a circuit schematic diagram of the status display module in the present invention;

[0032] Fig.11 It is a circuit schematic diagram of the power module in the present invention.

[0033] Among them, the reference numerals in the figure are: 1. main control module; 2. gain switching module; 201. gain unit; 202. microcontroller; 3. gain module; 4. signal enhancement module; 5. feedback acquisition module; 6. bias voltage zero point adjustment module; 7. control module; 701. remote control unit; 702. local control unit; 8. status display module; 9. power supply module. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] It should be noted that when a component is referred to as being "fixed" or "set" or "connected" to another component, it may be located directly or indirectly on the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and should not be construed as limitations on the present technical solution. The terms "first", "second", etc. are only used for the convenience of description and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0036] like Figure 1 As shown, a bridge signal amplification system described in one embodiment of the present invention includes a gain module 3, a gain switching module 2, and a main control module 1. The gain module 3 is used to gain input signals and output gain signals; the gain switching module 2 includes multiple gain units 201, and each gain unit 201 can be selectively connected to the gain module 3 to adjust the gain ratio, and the gain units 201 have different corresponding gain ratios; the main control module 1 selects the gain unit 201 connected to the gain module 3 to select the gain ratio.

[0037] The gain switching module 2 includes a plurality of gain units 201 with different gain ratios, and each gain unit 201 can be selectively connected to the gain module 3 as needed to adjust the overall gain ratio. During operation, the main control module 1 intelligently selects and connects the corresponding gain unit 201 according to the sensor type and the strength of the input bridge signal, thereby realizing flexible adjustment of the gain ratio. When the bridge signal is weak, the main control module 1 will select a gain unit 201 with a higher gain ratio; and when the bridge signal is strong, a gain unit 201 with a lower gain ratio will be selected to ensure the stability and accuracy of the output signal. The electrical signal after the non-electrical parameter is converted by the sensor is input into the gain module 3, and the gain module 3 performs gain processing on the input signal and outputs a gain signal.

[0038] In this embodiment, the bridge signal amplification system realizes intelligent selection and flexible adjustment of the gain ratio by setting the gain switching module 2 and the main control module 1, improves the system's adaptability to bridge signals of different strengths, and ensures the stability and reliability of the output signal. At the same time, the system can automatically select the most appropriate gain ratio according to different signal strengths, which can avoid signal distortion or saturation problems caused by improper gain. In addition, the gain unit 201 in the system can be modularly constructed, easy to expand and maintain, and convenient for subsequent upgrades and optimizations.

[0039] Specifically, Figure 3As shown, the gain module 3 includes an operational amplifier U8.1, an operational amplifier U8.2, an operational amplifier U7.1, and an operational amplifier U9. There are two external bridge signals, one of which is input to the positive input terminal of the operational amplifier U8.1, and a resistor R9 is connected between the reverse input terminal and the output terminal of the operational amplifier U8.1. The gain switching module 2 is connected between the reverse input terminal and the resistor R9 of the operational amplifier U8.1. Another external bridge signal is input to the positive input terminal of the operational amplifier U8.2, and a resistor R40 is connected between the reverse input terminal and the output terminal of the operational amplifier U8.2. The reverse input terminal of the operational amplifier U7.1 is connected to the output terminal of the operational amplifier U8.1 through a resistor R5, and a resistor R4 is connected between the reverse input terminal and the output terminal of the operational amplifier U7.1. The positive input terminal of the operational amplifier U7.1 is connected to the output terminal of the operational amplifier U8.2 through a resistor R6. The inverting input terminal of the operational amplifier U9 is connected to the output terminal of the operational amplifier 7.1 through R80, a resistor R81 is connected between the inverting input terminal and the output terminal of the operational amplifier U9, and the positive input terminal of the operational amplifier U9 is connected to the reference voltage of the power module 9.

[0040] like Fig.11 As shown, the power module 9 includes a first power module 9U3 for outputting a first voltage and a second power module 9U1 for outputting a second voltage. The model of the first power module 9U3 is DS8241-50S5, and the model of the second power module 9U1 is WL2851E33-5 / TR. The first voltage is 5V, and the second voltage is 3.3V, which are used to supply power to different components of the system. The output pin of the second power module 9U1 is connected to a third power module 9, and the third power module 9 is used to output a third voltage, and the third voltage is 2.5V. The third voltage is the reference voltage connected to the positive input terminal of the operational amplifier U9. The output terminal of the third power module 9 is connected to the positive input terminal of the operational amplifier U6.1, and the reverse input terminal of the operational amplifier U6.1 is connected to the output terminal. The output terminal of the operational amplifier U6.1 outputs a signal VOUT2.5.

[0041] like Figures 2 to 4 As shown, in a preferred embodiment, the gain switching module 2 includes a microcontroller 202 that is communicatively connected to the main control module 1, and each gain unit 201 is a resistor with different resistance values, and each gain unit 201 is respectively connected to each control pin of the microcontroller 202.

[0042] Specifically, the microcontroller 202 is an analog switch chip U4 model TMUX6208PWR, the main control module 1 is a microprocessor U5 model STM32F103C38T6, and the specific models of the analog switch chip U4 and the microprocessor U5 can be selected as needed and are not limited to the listed models.

[0043] The A0 pin, A1 pin, and A2 pin of the analog switch chip U4 are connected to the PA5 pin, PA6 pin, and PA7 pin of the main control module 1. The S1 pin, S2 pin, S3 pin, S4 pin, and S5 pin of the analog switch chip U4 are respectively connected to the first gain unit 201, the second gain unit 201, the third gain unit 201, the fourth gain unit 201, the fifth gain unit 201, and the sixth gain unit 201. The first gain unit 201 includes a resistor R12, R12 is left blank, and the gain ratio is 1; the second gain unit 201 includes a resistor R13, R13 is 49.9kΩ, and the gain ratio is 2; the third gain unit 201 includes a resistor R14 and a resistor R79 connected in series, R14 is 12kΩ, R79 is 470Ω, and the gain ratio is 5; the fourth gain unit 201 includes a resistor R15 and a resistor R78 connected in series, R15 is 5.1kΩ, R78 is 430Ω, and the gain ratio is 10; the fifth gain unit 201 includes a resistor R16 and a resistor R77 connected in parallel, R14 is 2.7kΩ, R77 is 91kΩ, and the gain ratio is 20; the sixth gain unit 201 includes a resistor R17 and a resistor R83 connected in series, R17 is 1kΩ, R83 is 10Ω, and the gain ratio is 50.

[0044] The microprocessor U5 outputs the corresponding control signal to the analog switch chip U4, and the analog switch chip U4 switches to the corresponding gain ratio to connect the corresponding resistor. Since the gain unit 201 is composed of resistors of different resistance values ​​and is switched by the analog switch chip, the system structure is simple, easy to implement and maintain. In addition, this design also enables the system to easily expand more gain units 201 to meet the needs of different application scenarios.

[0045] like Figure 5 As shown, in a preferred embodiment, a signal enhancement module 4 is provided at the rear stage of the gain module 3, and the signal enhancement module 4 is used to filter and reduce noise and perform buffering processing on the gain signal output by the gain module 3, and output an enhanced signal.

[0046] Specifically, the signal enhancement module 4 includes an operational amplifier follower circuit, and the operational amplifier follower circuit includes an operational amplifier 7.2. The positive input terminal of the operational amplifier 7.2 is connected to two first-order RC low-pass filters connected in series, forming a second-order active low-pass filter. The reverse input terminal of the operational amplifier 7.2 is connected to the capacitor C9, and the reverse input terminal of the operational amplifier 7.2 is connected to the output terminal, and the output terminal of the operational amplifier 7.2 outputs an enhanced signal. In this circuit, the operational amplifier U7.2 and the peripheral resistor and capacitor constitute a second-order low-pass active filter, which is also a voltage follower. The analog signal is buffered by the operational amplifier follower circuit to improve the driving ability of the signal.

[0047] In this embodiment, the high-frequency noise and interference in the input signal are effectively removed by filtering and noise reduction processing of the second-order active low-pass filter, thereby improving the signal-to-noise ratio of the signal. Secondly, the operational amplifier follower circuit enables stable transmission of the signal, reduces the attenuation and distortion of the signal during transmission, improves the driving ability of the signal, and enables the enhanced signal to drive the subsequent circuit more stably and efficiently.

[0048] like Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, in a preferred embodiment, a feedback collection module 5 is provided at the rear stage of the signal enhancement module 4 , and the feedback collection module 5 is used to feed back the enhanced signal to the main control module 1 .

[0049] Specifically, the output end of the operation amplifier U7.2 of the signal enhancement module 4 is connected to the PA2 pin of the microprocessor U5.

[0050] The gain module 3 is connected to the bias voltage zero point adjustment module 6 , and the main control module 1 controls the bias voltage zero point adjustment module 6 to perform compensation adjustment on the bias voltage of the gain module 3 according to the feedback signal of the feedback acquisition module 5 .

[0051] Specifically, the bias voltage zero adjustment module 6 includes an operational amplifier U6.2, the output end of the operational amplifier U6.2 is connected to the positive input end of the operational amplifier U7.1, a resistor R30 is connected between the reverse input end and the output end of the operational amplifier U6.2, and the positive input end of the operational amplifier U6.2 is connected to the microprocessor U5. The positive input end of the operational amplifier U6.2 is sequentially connected with resistors R22, R24, R29, R36, R42, R48, R52, R56, R60, R23, R28, R35, R41, R47, R51, R55, and R59, and the other end of the resistor R59 is grounded. The PB0 pin of the microprocessor U5 is connected between the resistor R59 and the resistor R55 through the resistor R58, the PB0 pin is connected between the resistor R59 and the resistor R55 through the resistor R58, the PB0 pin is connected between the resistor R59 and the resistor R55 through the resistor R58, the PB1 pin is connected between the resistor R51 and the resistor R55 through the resistor R53, the PB2 pin is connected between the resistor R47 and the resistor R51 through the resistor R49, the PB3 pin is connected between the resistor R41 and the resistor R47 through the resistor R44, the PB4 pin is connected between the resistor R35 and the resistor R41 through the resistor R38, the PB5 pin is connected between the resistor R28 and the resistor R35 through the resistor R33, and the PB6 pin is connected between the resistor R23 and the resistor R28 through the resistor R25 , the PB7 pin is connected between the resistor R60 and the resistor R23 through the resistor R20, the PB8 pin is connected between the resistor R56 and the resistor R60 through the resistor R57, the PB9 pin is connected between the resistor R52 and the resistor R56 through the resistor R54, the PB10 pin is connected between the resistor R48 and the resistor R52 through the resistor R50, the PB11 pin is connected between the resistor R42 and the resistor R48 through the resistor R45, the PB12 pin is connected between the resistor R36 and the resistor R42 through the resistor R39, the PB13 pin is connected between the resistor R29 and the resistor R36 through the resistor R34, the PB14 pin is connected between the resistor R24 ​​and the resistor R29 through the resistor R26, and the PB15 pin is connected between the resistor R22 and the resistor R24 ​​through the resistor R21.

[0052] The zeroing process is to make the output signal equal to the voltage of VOUT2.5 in static state. The microprocessor U5 collects the amplified output signal VOUT1 and compares it with the output voltage at VOUT2.5. If the voltages of VOUT1 and VOUT2.5 are equal, the zeroing process ends; otherwise, the microprocessor U5 adjusts the VBIAS voltage through the operational amplifier U6.2 by controlling the different outputs of the pins PB0 to PB15. The VBIAS voltage is fed back to the operational amplifier U7.1, thereby changing the output signal VOUT1. The microprocessor U5 collects VOUT1 again and compares it with VOUT2.5 until the voltages of VOUT1 and VOUT2.5 are equal. The external bridge signal has two inputs to the gain module 3. In static state (i.e. when there is no signal change in the bridge), there will be a slight difference between the two signals. After high-power amplification, the difference will be relatively large, which may cause the amplified signal to be saturated. When there is a signal change in the bridge, the useful signal cannot be amplified because of the signal saturation. Therefore, the zeroing process is performed to eliminate the static saturation.

[0053] like Figure 2 , Figure 8 and Fig. 9 As shown, in a preferred embodiment, the main control module 1 is connected to a control module 7 , and the control module 7 is used to control the bias voltage zero point adjustment module 6 to perform zero adjustment and select the gain unit 201 .

[0054] The control module 7 includes a remote control unit 701, and the remote control unit 701 is used to remotely control the bias voltage zero point adjustment module 6 to perform zero adjustment.

[0055] The remote control unit 701 sends an auto-zero signal to the PA3 pin of the microprocessor U5.

[0056] The control module 7 includes a local control unit 702 , and the local control unit 702 is used to manually control the bias voltage zero point adjustment module 6 to perform zero adjustment or select the gain unit 201 .

[0057] The local control unit 702 includes a button SW1, which is connected to the PA4 pin of the microprocessor U5. When the button SW1 is pressed for a short time, the gain unit 201 is switched sequentially; when the button SW1 is pressed for more than 5 seconds, zeroing is started.

[0058] In this embodiment, by combining remote control and local control, flexible control of the bias voltage zero adjustment module 6 and the gain unit 201 is achieved. The remote control function enables the user to monitor the system status and make necessary adjustments anytime and anywhere, without geographical restrictions, and is convenient for operation. The local control function provides the user with a direct means of operation, so that the user can instantly switch the gain unit 201 or perform a zeroing operation as needed.

[0059] like Figure 2 and Fig.10 As shown, in a preferred embodiment, the main control module 1 is connected to a status display module 8 , and the status display module 8 is used to display the status of the control module 7 .

[0060] Specifically, the status display module 8 includes an indicator light LED1, an indicator light LED2, an indicator light LED3, an indicator light LED4, an indicator light LED5, and an indicator light LED6. The indicator light LED1, the indicator light LED2, the indicator light LED3, the indicator light LED4, the indicator light LED5, and the indicator light LED6 are respectively connected to the PA8 pin, the PA9 pin, the PA10 pin, the PA11 pin, the PA12 pin, and the PA15 pin of the microprocessor U5, and the other ends are all connected to a 3.3V power supply. The indicator light LED1, the indicator light LED2, the indicator light LED3, the indicator light LED4, the indicator light LED5, and the indicator light LED6 respectively indicate the gain module 31 times gain, 2 times gain, 5 times gain, 10 times gain, 20 times gain, and 50 times gain.

[0061] When the control module 7 selects a different gain unit 201, the microprocessor U5 will send a signal to the corresponding indicator light through the corresponding pin according to the current gain setting. For example, if the gain module 3 is set to 1x gain, the microprocessor U5 will light up the indicator light LED1 through the PA8 pin; if it is set to 2x gain, it will light up LED2, and so on.

[0062] In this embodiment, by providing the status display module 8, it is convenient for the user to view the working status of the gain module 3, which significantly improves the readability and interactive friendliness of the system.

[0063] A sensor described in one embodiment of the present invention uses the above-mentioned bridge signal amplification system.

[0064] In this embodiment, through intelligent gain switching and precise gain adjustment, it can be applied to different sensors. Secondly, the filtering noise reduction and buffer processing functions of the signal enhancement module 4 improve the signal-to-noise ratio and stability of the signal, so that the measurement accuracy and reliability of the sensor are greatly improved. At the same time, the dual control mode of the remote control unit 701 and the local control unit 702 provides users with more flexible and convenient operation means. In addition, the introduction of the status display module 8 provides users with intuitive visual feedback, simplifies the operation process, and improves work efficiency.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A bridge signal amplification system, characterized in that: include: A gain module, the gain module is used to gain an input signal and output a gain signal; A gain switching module, wherein the gain switching module includes a plurality of gain units, each of which can be selectively connected to the gain module to adjust the gain ratio, and the gain units correspond to different gain ratios; A main control module, wherein the main control module selects a gain unit connected to the gain module to select a gain ratio.

2. A bridge signal amplification system according to claim 1, characterized in that: The gain switching module includes a microcontroller that is communicatively connected to the main control module. Each of the gain units is a resistor with a different resistance value, and each of the gain units is respectively connected to a control pin of the microcontroller.

3. A bridge signal amplification system according to claim 1, characterized in that: The gain module is provided with a signal enhancement module at the rear stage, and the signal enhancement module is used to filter and reduce noise and perform buffering processing on the gain signal output by the gain module, and output an enhanced signal.

4. A bridge signal amplification system according to claim 3, characterized in that: The signal enhancement module is provided with a feedback collection module at the rear stage, and the feedback collection module is used to feed back the enhanced signal to the main control module.

5. A bridge signal amplification system according to claim 4, characterized in that: The gain module is connected to a bias voltage zero point adjustment module, and the main control module controls the bias voltage zero point adjustment module to perform compensation adjustment on the bias voltage of the gain module according to the feedback signal of the feedback acquisition module.

6. A bridge signal amplification system according to claim 5, characterized in that: The main control module is connected to a control module, and the control module is used to control the bias voltage zero point adjustment module to perform zero adjustment and select the gain unit.

7. A bridge signal amplification system according to claim 6, characterized in that: The control module includes a remote control unit, and the remote control unit is used to remotely control the bias voltage zero point adjustment module to perform zero adjustment.

8. A bridge signal amplification system according to claim 6, characterized in that: The control module includes a local control unit, and the local control unit is used to manually control the bias voltage zero point adjustment module to perform zero adjustment or select the gain unit.

9. The bridge signal amplification system according to claim 6, characterized in that: The main control module is connected to a status display module, and the status display module is used to display the status of the control module.

10. A sensor, characterized in that: A bridge signal amplification system according to any one of claims 1 to 9 is used.

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