High-sensitivity vibration detection circuit

Abstract

The utility model provides a high-sensitivity vibration detection circuit. The high-sensitivity vibration detection circuit comprises a power supply module, an analog front end, a digital-to-analog conversion module and a microcontroller, the power supply module outputs 2.5 V voltage to the analog front end and the digital-to-analog conversion module, and an LTC6655 band-gap reference voltage source chip is adopted; the analog front end provides three paths of differential mode vibration sensor signal input channels, and is used for accessing three sensors to detect vibration signals in x, y and z three-axis directions and inputting the vibration signals into the digital-to-analog conversion module; the digital-to-analog conversion module converts an analog signal output by the analog front end into a 24-bit digital signal and sends the 24-bit digital signal to the microcontroller; and the controller encodes the received digital signal and transmits the encoded digital signal to an upper computer through a UART (Universal Asynchronous Receiver Transmitter) interface.

Description

Technical Field

[0001] This utility model relates to detection circuits, and more particularly to vibration detection circuits. Background Technology

[0002] Currently, vibration data is one of the key parameters that needs to be monitored for health status prediction and fault diagnosis of industrial equipment. Therefore, various data acquisition modules and different types of vibration sensors are often seen installed on the equipment under test in industrial settings to obtain vibration parameters. Existing vibration detection circuits suffer from low sensitivity, which urgently needs to be addressed. Utility Model Content

[0003] The main technical problem to be solved by this utility model is to provide a vibration detection circuit with high sensitivity.

[0004] To solve the above-mentioned technical problems, this utility model provides a high-sensitivity vibration detection circuit, including: a power supply module, an analog front end, a digital-to-analog conversion module, and a microcontroller;

[0005] The power supply module outputs a 2.5V voltage to the analog front-end and digital-to-analog converter module, using an LTC6655 bandgap reference voltage source chip;

[0006] The analog front end provides three differential mode vibration sensor signal input channels, which are used to connect three sensors to detect vibration signals in the x, y, and z axes and input them into the digital-to-analog conversion module.

[0007] The analog-to-digital converter module converts the analog signal output from the analog front end into a 24-bit digital signal and sends it to the microcontroller; the microcontroller encodes the received digital signal and transmits it to the host computer through the UART interface.

[0008] In a preferred embodiment: the digital-to-analog converter module is an ADS1256 digital-to-analog converter chip.

[0009] In a preferred embodiment: the power supply module outputs a 2.5V voltage and ground potential, which pass through a differential channel and a low-pass filter composed of resistors R1, R2, capacitors CE1, C3, and C18, and then enter the digital-to-analog converter module to form positive and negative reference levels.

[0010] In a preferred embodiment: the microcontroller is an LPC1114 microprocessor chip, which is connected to the digital-to-analog converter module via an SPI interface to control the channel switching of the digital-to-analog converter module.

[0011] In a preferred embodiment: the differential mode vibration sensor signal input channel, through resistors R15 and R16, capacitors C33 and C37, and resistors R17 and R20, capacitors C34 and C38, constitutes a differential balanced signal input channel, and simultaneously forms two second-order low-pass filter circuits; the differential balanced signal input channel, after being connected across capacitor C45, enters the differential input terminals AN0 and AN1 of the digital-to-analog conversion module.

[0012] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0013] This invention provides a high-sensitivity vibration detection circuit with extremely high sensitivity and dynamic range. The circuit uses a 24-bit precision ADC chip and an external 2.5V precision voltage reference, providing a dynamic range of >130dB.

[0014] This invention provides a high-sensitivity vibration detection circuit. The analog front end adopts a differential input method, which can effectively filter out common-mode interference and improve the detection capability of weak signals. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the power supply module in a preferred embodiment of the present invention;

[0016] Figure 2 This is a circuit diagram of the simulated front end in a preferred embodiment of the present invention;

[0017] Figure 3 This is a circuit diagram of the digital-to-analog conversion module in a preferred embodiment of the present invention;

[0018] Figure 4 This is a circuit diagram of the microcontroller in a preferred embodiment of the present invention;

[0019] Figure 5 This is the overall circuit diagram of the microcontroller in a preferred embodiment of the present invention. Detailed Implementation

[0020] To make the technical solution and features of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only for illustrating this utility model and are not intended to limit the scope of this utility model. After reading this utility model, any modifications of this utility model by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0021] refer to Figures 1-5 This embodiment provides a high-sensitivity vibration detection circuit, including: a power supply module, an analog front end, a digital-to-analog conversion module, and a microcontroller;

[0022] The power supply module outputs 2.5V to the analog front-end and digital-to-analog converter module, employing the LTC6655 bandgap reference voltage source chip. The LTC6655 precision bandgap reference voltage source chip has a temperature drift of <2ppm / ℃ and an output potential deviation of <±0.025%, making it ideal for high-resolution measurements required by instrumentation and testing equipment. Furthermore, this chip can operate normally within a temperature range of -40℃ to 125℃, thus ensuring suitability for demanding industrial environments.

[0023] The analog front end provides three differential mode vibration sensor signal input channels for connecting three sensors to detect vibration signals in the x, y, and z axes and inputting them into the digital-to-analog converter module. Taking channel one as an example, the differential mode vibration sensor signal input channel, through resistors R15 and R16, capacitors C33 and C37, and resistors R17 and R20, capacitors C34 and C38, forms a differential balanced signal input channel, which also constitutes two second-order low-pass filter circuits. The differential balanced signal input channel, after being connected across capacitor C45, enters the differential input terminals AN0 and AN1 of the digital-to-analog converter module. After the common-mode interference signal enters the circuit, it will generate an equal potential across capacitor C45 and AN0 and AN1, which is canceled out by this balanced input channel and cannot enter the precision ADC sampling.

[0024] The analog-to-digital converter (ADC) module converts the analog signal output from the analog front-end into a 24-bit digital signal, which is then sent to the microcontroller. The microcontroller encodes the received digital signal and transmits it to the host computer via a UART interface. In this embodiment, the ADC module is an ADS1256 ADC chip. This chip is a 24-bit, 30kSPS, 8-channel, Δ-Σ ADC. It features an internal gain control (PGA) function, making it suitable for weak signal measurement. It provides an effective resolution of 23 bits, a maximum nonlinear distortion of ±0.0010%, and has internal hardware oversampling and an internal programmable digital filter. The 8 analog input channels can form 4 pairs of differential signal inputs, making it ideal for high-precision measurements. The power supply module outputs 2.5V and ground potential, which pass through the differential channels and a low-pass filter composed of resistors R1 and R2, and capacitors CE1, C3, and C18, respectively, before entering the ADC module to form positive and negative reference levels.

[0025] Finally, the microcontroller is an LPC1114 microprocessor chip, which is connected to the digital-to-analog converter module via an SPI interface to control the channel switching of the digital-to-analog converter module.

[0026] The above is only one specific embodiment of the present utility model, but the design concept of the present utility model is not limited thereto. Any non-substantial modifications made to the present utility model using this concept shall be deemed as an infringement of the protection scope of the present utility model.

Claims

1. A high-sensitivity vibration detection circuit, characterized in that... include: Power supply module, analog front end, digital-to-analog converter module and microcontroller; The power supply module outputs a 2.5V voltage to the analog front-end and digital-to-analog converter module, using an LTC6655 bandgap reference voltage source chip; The analog front end provides three differential mode vibration sensor signal input channels, which are used to connect three sensors to detect vibration signals in the x, y, and z axes and input them into the digital-to-analog conversion module. The analog-to-digital converter module converts the analog signal output from the analog front end into a 24-bit digital signal and sends it to the microcontroller; the microcontroller encodes the received digital signal and transmits it to the host computer through the UART interface.

2. The high-sensitivity vibration detection circuit according to claim 1, characterized in that: The digital-to-analog conversion module is an ADS1256 digital-to-analog conversion chip.

3. The high-sensitivity vibration detection circuit according to claim 1, characterized in that: The power supply module outputs 2.5V voltage and ground potential, which pass through a differential channel and a low-pass filter composed of resistors R1, R2, capacitors CE1, C3, and C18, and then enter the digital-to-analog converter module to form positive and negative reference levels.

4. The high-sensitivity vibration detection circuit according to claim 1, characterized in that: The microcontroller is an LPC1114 microprocessor chip, which is connected to the digital-to-analog converter module via an SPI interface to control the channel switching of the digital-to-analog converter module.

5. The high-sensitivity vibration detection circuit according to claim 1, characterized in that: The differential mode vibration sensor signal input channel, through resistors R15 and R16, capacitors C33 and C37, and resistors R17 and R20, capacitors C34 and C38, forms a differential balanced signal input channel, which also constitutes two second-order low-pass filter circuits; the differential balanced signal input channel, after being connected across capacitor C45, enters the differential input terminals AN0 and AN1 of the digital-to-analog conversion module.

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