Voltage output voltage stabilizing device of intelligent sensor

Abstract

The invention relates to a voltage output voltage-stabilizing device of an intelligent sensor. The voltage output voltage-stabilizing device comprises a power supply module which is used for providing a stable power supply for the whole device and realizing over-current protection, EMI protection and reverse connection prevention protection of the power supply; the accelerometer and microcontroller module comprises an accelerometer and a microcontroller which communicate with each other, and is used for realizing acceleration signal acquisition and data processing, operational amplifier power supply control and voltage output control; the DAC output voltage stabilizing circuit module comprises an operational amplifier connected with the microcontroller and is used for outputting voltage signals and performing EMI protection, reverse connection protection and overcurrent protection; the output self-checking module is respectively connected with the DAC output voltage stabilizing circuit module and the microcontroller and is used for sampling an output voltage signal; and the operational amplifier power supply control module is respectively connected with the DAC output voltage stabilizing circuit module and the microcontroller and is used for controlling a power switch of the DAC output voltage stabilizing circuit module. Compared with the prior art, the system has the advantages of high stability, strong anti-interference capability, low noise and the like.

Description

Technical Field

[0001] The invention relates to the field of intelligent sensor production design, in particular to a voltage output stabilizing device for an intelligent sensor. Background Art

[0002] In modern electronic devices, especially smart sensors, continuous and stable voltage output is essential to ensure the normal operation of the device and extend the service life of the device. Unstable voltage can cause inaccurate sensor readings, abnormal operation, or even damage.

[0003] In the 0.5V-4.5V analog voltage output inclination sensor products, due to the harsh working conditions, the inclination sensor products are affected by the electromagnetic influence of the working environment, resulting in unstable voltage power supply, output jump and inability to return to zero. In order to meet the needs of different working conditions and markets and improve the adaptability and reliability to harsh working conditions, it is necessary to improve and upgrade the existing hardware circuit and design a high-performance intelligent sensor voltage output stabilization device. Summary of the invention

[0004] The purpose of the present invention is to provide a voltage output stabilizing device for an intelligent sensor in order to overcome the defects of the above-mentioned prior art. By optimizing the circuit design and applying advanced protection mechanisms, the high stability and high reliability of the output voltage signal are ensured, and the performance problems of the intelligent sensor caused by voltage fluctuations and electromagnetic interference are reduced.

[0005] The voltage output stabilizing device comprises:

[0006] Power module: used to provide stable power to the entire device and realize over-current protection, EMI protection and reverse connection protection of the power supply;

[0007] Accelerometer and microcontroller module: including an accelerometer and a microcontroller that communicate with each other to realize acceleration signal acquisition and data processing, operational amplifier power supply control, and voltage output control;

[0008] DAC output voltage regulator circuit module: including an operational amplifier connected to the microcontroller to output voltage signals as well as EMI protection, reverse connection protection and overcurrent protection;

[0009] Output self-test module: connected to the DAC output voltage stabilization circuit module and the microcontroller respectively to sample the output voltage signal;

[0010] Operational amplifier power supply control module: connected to the DAC output voltage stabilizing circuit module and the microcontroller respectively, to control the power switch of the DAC output voltage stabilizing circuit module.

[0011] Furthermore, the power module includes an EMI and anti-reverse connection protection circuit, a DC-DC power supply circuit and an LDO circuit which are arranged in sequence. The EMI and anti-reverse connection protection circuit is connected to an external power supply, and overcurrent protection, EMI protection and anti-reverse connection protection are achieved through a first fuse, a first varistor and a first transient voltage suppression diode.

[0012] Furthermore, the EMI and reverse connection protection circuit also decouples the power input through a filter capacitor, filters out high-frequency noise in the external power supply, and smoothes the input voltage of the external power supply.

[0013] Furthermore, the DAC output voltage stabilization circuit module also includes a preliminary voltage regulation submodule, a high-frequency noise filtering submodule, a feedback network submodule, an EMI protection / reverse connection / current protection submodule and a signal regulation submodule. Pin 1 IN+ of the operational amplifier is connected to the DAC port of the microcontroller MCU through the signal regulation submodule, pin 2 V- is grounded, pin 3 IN- and pin 4 OUT are grounded through the feedback network submodule, pin 5 V+ is connected to the output end of the operational amplifier power supply control module through the preliminary voltage regulation submodule, and pin 4 OUT is connected to the output self-test module and the device output end after passing through the EMI protection / reverse connection / current protection submodule, and the high-frequency noise filtering submodule is arranged between pin 5 V+ and the preliminary voltage regulation submodule.

[0014] Furthermore, the signal regulation submodule is composed of two resistors connected in parallel, the preliminary voltage regulation submodule is a step-down resistor, which is arranged between pin 5 V+ and the output end of the op amp power supply control module, the feedback network submodule includes a first resistor and a second resistor connected in series, the pin 3 IN- is grounded through the first resistor, and the pin 4 OUT is grounded through the first resistor and the second resistor connected in series, the EMI protection / reverse connection / current protection submodule includes a TVS diode arranged between pin 4 OUT and ground, a varistor arranged between the output end of the device and the ground, and a second fuse arranged between pin 4 OUT and the output end of the device, and the high-frequency noise filtering submodule includes two filter capacitors arranged in parallel.

[0015] Furthermore, the output self-test module includes a voltage divider module and a clamping diode. The microcontroller is connected to the analog ground through the voltage divider module. The voltage divider module is composed of a third resistor and a fourth resistor that are connected in series and have equal resistance values. The output end of the device is connected between the third resistor and the fourth resistor, and is connected to the analog ground through the clamping diode.

[0016] Furthermore, the operational amplifier power supply control module includes a bias network, a transistor and a field effect transistor, the bias network is composed of a fifth resistor, a sixth resistor and a seventh resistor, the base of the transistor is connected to the GPIO port of the microcontroller through the sixth resistor and is grounded through the fifth resistor, the emitter of the transistor is grounded, the collector of the transistor is connected to the gate of the field effect transistor through the seventh resistor, the source of the field effect transistor is connected to the power supply module, and the drain of the field effect transistor is connected to the operational amplifier as the power supply end of the DAC output voltage stabilization circuit module.

[0017] Furthermore, the voltage output stabilizing device also includes a working indicator light circuit module connected to the microcontroller, and the working indicator light circuit module includes two LED lights of different colors and matching driving elements to indicate different working states.

[0018] Furthermore, the voltage output stabilizing device also includes a zeroing button circuit module connected to the microcontroller, the zeroing button circuit module includes a physical button, a pull-up resistor, a current limiting resistor, a second varistor and a second transient voltage suppression diode, one end of the physical button is grounded, and the other end is connected to the zeroing port of the microcontroller through the current limiting resistor, one end of the pull-up resistor is connected to the power supply module, and the other end is connected to the zeroing port of the microcontroller, one end of the second varistor is connected to the zeroing port of the microcontroller, and the other end is grounded, and one end of the second transient voltage suppression diode is connected to the zeroing port of the microcontroller, and the other end is grounded.

[0019] When the device is working normally, the accelerometer sends the detected acceleration information to the microcontroller, the microcontroller processes the data to obtain the angle data, and outputs the corresponding voltage signal through the DAC output voltage stabilization circuit module according to the corresponding linear relationship. In this process, the output self-test module divides the output voltage signal in real time and samples it to the microcontroller. The microcontroller compares the sampling result with the set value or range to determine whether the output voltage signal is normal. If it is abnormal, the operational amplifier power supply control module is controlled to stop supplying power to the operational amplifier of the DAC output voltage stabilization circuit module, and the reference voltage signal output of the operational amplifier is turned off. The microcontroller also issues an abnormal alarm through the working indicator light circuit module.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. High stability: The present invention adds a DAC output voltage stabilization circuit module, combines precision resistors and filter capacitors to filter out high-frequency noise in the input signal to ensure purity, amplifies the signal through an operational amplifier, and adjusts the gain in combination with a feedback network to provide a highly stable voltage output.

[0022] 2. Strong anti-interference ability: The present invention respectively sets TVS diodes and filter capacitors at the EMI and anti-reverse protection circuit of the power module and the output end of the operational amplifier of the DAC output voltage stabilization circuit module, which can effectively suppress electromagnetic interference and transient voltage fluctuations and increase the adaptability of the device under harsh electromagnetic working conditions.

[0023] 3. Perfect protection mechanism: The present invention sets multiple protection mechanisms in the DAC output voltage stabilization circuit module, adopts TVS diodes and varistors for EMI protection and reverse connection protection, ensures that the circuit can still work stably in harsh environments, and current protection is achieved through fuses to prevent excessive current from damaging circuit components. In addition, the output signal of the DAC1 port of the microcontroller MCU is accurately adjusted through resistors to provide a stable reference voltage for the operational amplifier, ensuring the reliability of the circuit in various working environments.

[0024] 4. Low noise: The present invention adopts an operational amplifier with low noise characteristics in the DAC output voltage stabilization circuit module to ensure the purity of the output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the circuit structure principle of the voltage output stabilizing device of the present invention;

[0026] Figure 2 It is a circuit structure diagram of the EMI and anti-reverse connection protection circuit;

[0027] Figure 3 is a schematic diagram of the circuit structure of the accelerometer and microcontroller module;

[0028] Figure 4 It is a schematic diagram of the circuit structure of the output self-test module;

[0029] Figure 5 It is a schematic diagram of the circuit structure of the operational amplifier power supply control module;

[0030] Figure 6 It is a circuit structure diagram of a DAC output voltage stabilization circuit module;

[0031] Figure 7 It is a circuit structure diagram of a working indicator light circuit module;

[0032] Figure 8 It is a circuit structure diagram of the zero-setting button circuit module;

[0033] Fig. 9 It is a voltage output characteristic curve diagram of the voltage output stabilizing device of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0035] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0036] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0038] In the description of this embodiment, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Example

[0041] Based on the high precision and high stability of the operational amplifier, the present invention designs a voltage output stabilizing device which can effectively suppress electromagnetic interference (EMI) and transient voltage fluctuations by combining components such as resistors, capacitors, diodes and TVS diodes.

[0042] like Figure 1 As shown, Figure 1The circuit structure principles of multiple functional modules of the voltage output voltage regulator are demonstrated, including power module, accelerometer and microcontroller module, output self-test module, op amp power control module, DAC output voltage regulator circuit module, working indicator circuit module and zeroing button circuit module. As a complete circuit system, it covers power protection, signal processing, detection and safety functions. The acceleration signal is collected in real time by the accelerometer, and the microcontroller MCU performs data processing. Finally, a stable signal output is achieved through the DAC output voltage regulator circuit module. In this process, the output self-test module and the op amp power control module ensure the output reliability. At the same time, the stability of the power supply and the high reliability of the output jointly ensure the stable operation of the entire system.

[0043] The following is an introduction to each functional module:

[0044] (1) A power module connected to an external +12V power supply includes an EMI and anti-reverse connection protection circuit, a DC-DC power supply circuit, and an LDO circuit connected in series. The module is used to provide +7V and 3.3V power supplies and has EMI and anti-reverse connection protection functions.

[0045] like Figure 2 As shown, the EMI and reverse connection protection circuit includes the following components:

[0046] Fuse F1: Set on the positive line of the external +12V power supply. In this example, a 100mA fuse is used as the first line of defense to protect the circuit. When the current is too large, the fuse blows to protect the subsequent circuit from overcurrent damage.

[0047] Varistor M1: It is set between the positive pole of the external +12V power supply and the ground. In this example, a 470KD07 varistor is used to prevent the circuit from overvoltage. When the voltage exceeds the set threshold, it becomes a low-resistance state, absorbing transient high voltage to prevent high voltage from damaging the circuit.

[0048] Transient voltage suppression diode D2: It is set between the positive pole of the external +12V power supply and the ground. In this example, the SMBJ30CA transient voltage suppression diode is used to suppress surge current or transient high voltage. It can quickly respond to high voltage pulses and clamp them within the safe voltage range to protect subsequent circuits.

[0049] Diode D3: The positive pole is connected to the positive pole of the external +12V power supply through the fuse F1, and the negative pole is connected to the DC-DC power supply circuit. In this example, a rectifier diode is used mainly for reverse connection protection to ensure that the subsequent circuit will not be damaged when the positive and negative poles of the power supply are reversed. If the power supply is reversed, the diode will enter the on state, forming a short circuit to protect other components.

[0050] Capacitor C5: It is set between the positive pole of the external +12V power supply and the ground, and its positive plate is connected to the negative pole of the diode D3. In this example, a 100uF / 50V capacitor is used. Its main function is to decouple the power input, filter out high-frequency noise in the power supply and smooth the input voltage.

[0051] In addition, the input end of the DC-DC power supply circuit is connected to the output end of the EMI and anti-reverse connection protection circuit to output a +7V power supply, and the input end of the LDO circuit is connected to the output end of the DC-DC power supply circuit to output a +3V power supply. The DC-DC power supply circuit is provided with a DC-DC power supply chip and peripheral circuits, and the LDO circuit is provided with a voltage regulator chip and peripheral circuits. In the present invention, the DC-DC power supply circuit combined with the LDO circuit can realize active filtering, and can also improve the voltage regulation accuracy of the output voltage. At the same time, the efficiency of the power supply module will not be significantly reduced.

[0052] In summary, the power module provides a complete protection mechanism for the power input end, and is suitable for applications in smart sensors where the power input is more complex and there may be risks of overvoltage, surge or reverse connection.

[0053] (2) Accelerometer and microcontroller module, used to collect and process acceleration signals, as well as other functions (indicator light control, case zeroing, output voltage collection self-test, etc.), such as Figure 3 As shown, the module includes:

[0054] Accelerometer U1: connected to the output end of the LDO circuit, used to detect the acceleration signal and send the signal to the microcontroller MCU for processing;

[0055] Microcontroller MCU: The pins of MCU are connected to the accelerometer U1 and other peripheral devices to digitize the signals and communicate with the accelerometer U1 through the SPI port.

[0056] (3) The output self-test module is connected to the microcontroller MCU and the DAC output voltage stabilization circuit module. Through the voltage divider circuit and diode protection, the output voltage status signal is transmitted to the ADC1 port of the microcontroller MCU with the set voltage sampling resolution to perform self-test and monitoring to ensure that the output voltage is within the normal range. Figure 4 As shown, the module specifically includes:

[0057] Voltage divider circuit: It is composed of resistor R8 and resistor R11. In this example, the resistance of the two resistors is 15kΩ. One end of the resistor R8 is connected to the ADC1 port of the microcontroller MCU to receive the divided signal ADC_IN1 (this signal is used to detect the output voltage). One end of the resistor R8 is directly connected to the output end of the DAC output voltage regulator circuit module. One end of the resistor R11 is connected to the output end of the DAC output voltage regulator circuit module, and the other end is connected to the analog ground.

[0058] Diode D5: One end of the diode is connected to the output end of the DAC output voltage regulator circuit module, and the other end is connected to the analog ground. It is used to protect the circuit to prevent excessive voltage or reverse voltage from damaging the ADC1 port input. It can clamp the voltage so that the ADC1 port voltage does not exceed the specified range.

[0059] Analog ground AGND: separated from the digital ground to reduce the impact of ground current interference on sensitive analog signals.

[0060] (4) Operational amplifier power supply control module, which is connected to the microcontroller MCU and the DAC output voltage regulator circuit module. Through the combination of transistors and field effect transistors, the DAC output voltage regulator circuit module power switch is effectively controlled to ensure power supply when needed. At the same time, the diode D7 is used to prevent the power supply from flowing in reverse. Figure 5 As shown, the module specifically includes:

[0061] Bias network: resistors R14, R15, and R16 together constitute the bias network of transistor Q3, which is used to control the conduction state of transistor Q3, wherein one end of resistor R14 is connected to the base of transistor Q3, and the other end is grounded, one end of resistor R15 is connected to the base of transistor Q3, and the other end is connected to the GPIO4 port of the microcontroller MCU, and resistor R16 is connected between the collector of transistor Q3 and the gate of field effect transistor Q4;

[0062] In this example, the value of resistor R14 is 100 kΩ, the value of resistor R15 is 3.3 kΩ, and the value of resistor R16 is 10 kΩ;

[0063] Transistor Q3: In this example, an NPN transistor is used to amplify and control the signal. The base receives the control signal V_A_CTRL from the GPIO4 port of the microcontroller MCU through the resistor R14 to control the switch of the DAC output voltage regulator circuit module. The collector is connected to the gate of the field effect transistor Q4 through the resistor R16, and the emitter is grounded.

[0064] Diode D7: The diode D7 is connected between the gate of the field effect transistor Q4 and the +7V power supply to prevent reverse current to achieve circuit protection, avoid voltage backflow, and protect downstream components;

[0065] Field effect transistor Q4: The source of the field effect transistor Q4 is connected to the +7V power supply, and the drain is the output terminal, which is connected to the DAC output voltage regulator circuit module. A resistor R17 is provided between the source and the gate of the field effect transistor Q4. In this example, the field effect transistor Q4 uses a FET field effect transistor as a switch tube to control the final power supply output of the operational amplifier power supply control module. By controlling the voltage of its gate, the power supply can be cut off or connected.

[0066] When the V_A_CTRL signal is valid (e.g., logic high), the base current of transistor Q3 flows in through R15, transistor Q3 is turned on, causing the gate voltage of field effect transistor Q4 to drop, and field effect transistor Q4 is turned on, thereby realizing the power supply to the DAC output voltage stabilizing circuit module. If the V_A_CTRL signal is invalid, transistor Q3 is cut off, the gate voltage of field effect transistor Q4 remains at a high level, field effect transistor Q4 is disconnected, the power supply to the op amp stops, and diode D7 plays a protective role to prevent the reverse flow of power and protect the safe operation of the circuit.

[0067] In summary, the output self-test module is combined with the op amp power supply control module to collect the status signal of the output voltage, and send the divided signal to the ADC1 port of the microcontroller MCU for monitoring and self-test. Through the voltage divider circuit, it can ensure that the voltage input to the ADC1 port is always kept within a safe range, and additional protection is provided by diode D5.

[0068] (5) DAC output voltage regulator circuit module: connected to the output end of the operational amplifier power supply control module, the input end of the output self-test module and the DAC1 port of the microcontroller MCU, respectively. Figure 6 As shown, the module specifically includes:

[0069] Operational amplifier U2: The operational amplifier model used in this example is LM321, which is used for signal amplification and regulation. It has low power consumption, high input impedance and good frequency response characteristics, and is suitable for the voltage stabilization circuit of the intelligent sensor. Pin 1 IN+ of the operational amplifier U2 is connected to the DAC1 port of the microcontroller MCU through parallel resistors R7 and R9, pin 2 V- is grounded, pin 3 IN- is grounded through resistor R10, pin 4 OUT is used as the output terminal, and is grounded through resistors R13 and R10 in turn, and pin 5 V+ is connected to the output terminal of the operational amplifier power supply control module through resistor R12;

[0070] Input signal processing: The signal output from the operational amplifier power supply control module undergoes preliminary voltage adjustment through resistor R12 to ensure that the operational amplifier U2 input signal V+ is within the appropriate voltage range, and then through capacitors C6 and C7 to filter out high-frequency noise to ensure the purity of the input signal;

[0071] Signal amplification and regulation: Operational amplifier U2 amplifies the input signal V+ and outputs a stable voltage signal VOUT_X. The feedback network composed of resistors R10 and R13 is used to adjust the gain and stability of operational amplifier U2.

[0072] Protection mechanism: TVS diode D6 (SMBJ6.5CA in this example) and varistor M3 (CT1812K40G in this example) are used for EMI protection and reverse connection protection to ensure that the circuit can still work stably in harsh environments. Current protection is achieved through fuse F2 (200mA fuse is used in this example) to prevent excessive current from damaging circuit components. Resistors R7 and R9 are used to accurately adjust the output signal DAC_OUT1 of the DAC1 port of the microcontroller MCU to provide a stable reference voltage.

[0073] (6) Working indicator light circuit module: This module is connected to the GPIO2 and GPIO3 ports of the microcontroller MCU respectively. It mainly consists of two LED lights of different colors (green and red) and the corresponding driving circuits, such as Figure 7 As shown, specifically including:

[0074] LED driver: D1 is a dual-color LED lamp, including two light-emitting diodes, green and red. By adjusting the current flowing through these two diodes, different colors of lights can be lit to indicate different states.

[0075] Current limiting resistors R1 and R2: In this example, R1 and R2 are both 510 ohm current limiting resistors, which are used to limit the current through transistors Q1 and Q2 respectively to prevent overcurrent damage to the LED;

[0076] Transistor Q1 and Q2: The emitters of transistors Q1 and Q2 are grounded respectively, and the bases are connected to the corresponding microcontroller ports through the corresponding resistors R4 and R6 respectively, and the collectors are connected to the LEDs through the corresponding current limiting resistors R1 and R2 respectively. In this example, transistors Q1 and Q2 use NPN transistors, which are responsible for controlling the on and off of the LEDs. The green and red lights are controlled by the GPIO3 and GPIO2 ports of the microcontroller MCU respectively. When the GPT03 port gives a base signal to transistor Q1, transistor Q1 is turned on and the green LED is on. Similarly, when the GPT02 port gives a signal to transistor Q2, transistor Q2 is turned on and the red LED is on.

[0077] Working status indication: The on and off of the LED can indicate the working status and temperature compensation status of the device. For example, the green LED on indicates normal working status, and the red LED on indicates abnormal status or the need for temperature compensation.

[0078] Current limiting resistors R4 and R6: In this example, R4 and R6 are both 3.3K ohms, which are used to limit the current of the LED lamp to ensure that the LED works stably for a long time.

[0079] This module ensures clear indicator light prompts in different states, making it easy for users to monitor the operating status of the equipment in real time.

[0080] (7) Zero reset button circuit module, which is connected to GPIO1 of the microcontroller MCU to realize the reset function and has certain protection measures, such as Figure 8 As shown, specifically including:

[0081] Button S1: Button S1 is a physical button. When pressed, the signal terminal BUTTON (connected to GPIO1 of the microcontroller MCU) is directly pulled to the ground GND to achieve the zeroing operation of the button input signal. This button is used for reset or zeroing operation;

[0082] Pull-up resistor R5: One end of the pull-up resistor R5 is connected to the +3.3V power supply, and the other end is connected to the signal terminal BUTTON. In this example, the value is 10k ohms. Its function is to pull the BUTTON signal to +3.3V when the button S1 is not pressed, and keep it in a high level state. When the button S1 is not pressed, the BUTTON pin will always maintain a logic high level state;

[0083] Current limiting resistor R3: set between button S1 and signal terminal BUTTON. In this example, the value of current limiting resistor R3 is 220 ohms, which is used to limit the current from button S1 to ground to prevent excessive current from being generated when button S1 is pressed.

[0084] Varistor M2: One end is connected between the button S1 and the current limiting resistor R3, and the other end is grounded. In this example, the varistor M2 is model 470KD07, which is used to absorb high voltage transients that may occur in the circuit, protect the subsequent circuit from the impact of surge voltage, and prevent damage to the circuit due to excessive voltage;

[0085] Transient voltage suppression diode D4: one end is connected between the current limiting resistor R3 and the signal terminal BUTTON, and the other end is grounded. In this example, the transient voltage suppression diode D4 adopts the model SMFJ3.3CA, and its rated voltage is 3.3V. It is used to clamp the overvoltage within a safe range when the circuit is disturbed by transient voltage, so as to further protect the circuit;

[0086] Decoupling capacitor C4: one end is connected to the signal terminal BUTTON, and the other end is grounded. In this example, the decoupling capacitor C4 is 100nF, which is used to filter out high-frequency noise that may be generated in the circuit, ensure signal stability, and prevent the circuit from malfunctioning due to transient noise.

[0087] The zero-setting button circuit module not only realizes the zero-setting function of the button, but also realizes effective and comprehensive protection of the circuit against overvoltage, transient voltage and high-frequency noise through the combination of varistors, transient voltage suppression diodes and decoupling capacitors, thereby ensuring the stability and reliability of the circuit.

[0088] The working principle of the present invention is as follows:

[0089] Based on the above voltage output stabilizing device, taking the application of the tilt sensor product with a range of ±45° (0.5V-4.5V) (it can also be other intelligent sensor products, including draw-wire sensors, long angle sensors, pressure sensors, etc.) as an example, its output characteristic curve is as follows: Fig. 9 As shown in FIG. 1 , the input (X axis) of the voltage output stabilizing device is the tilt angle value calculated by the microcontroller MCU according to the acceleration output data of the accelerometer through the angle algorithm (sine or tangent algorithm), and the output is a 0.5-4.5V voltage value (Y axis). Fig. 9 It can be seen that the input and output of the voltage output stabilizing device are linearly related within the angle range;

[0090] When the inclination sensor product is working normally, the accelerometer U1 sends the detected acceleration information to the microcontroller MCU according to the current position. The microcontroller MCU calculates the angle data through the built-in angle algorithm, and outputs the corresponding voltage signal according to the corresponding linear relationship. During this process, the output self-test module divides the voltage signal output by the inclination sensor in real time and samples it to the microcontroller MCU. The microcontroller MCU determines whether the output voltage signal is normal based on the comparison between the sampling result and the set value or range. If it is abnormal, the operational amplifier power supply control module is controlled through the GPIO4 port to stop supplying power to the operational amplifier U2 of the DAC output voltage stabilizing circuit module, and the reference voltage signal output of the DAC1 port is turned off. The microcontroller MCU also issues an abnormal alarm through the working indicator light circuit module.

[0091] In addition, the present invention also provides a key zeroing function. After pressing the zeroing button S1, the indicator light flashes red and green alternately for 5 seconds, and the color of the indicator light will no longer change. At this time, release the zeroing button, and then press and release the zeroing button three times within 10 seconds to enter the zero point setting state. Subsequently, the red and green lights will flash alternately for two seconds, and finally the green light will be on, indicating that the setting is completed, and the output voltage signal corresponding to the current position of the zero position is set to 2.5V.

[0092] To sum up, the voltage output stabilizing device of an intelligent sensor provided by the present invention is suitable for various electronic devices that require high-precision voltage output, especially various intelligent sensors (inclination, pull rope, long angle, pressure and other sensors). Specific applications include but are not limited to torque limiters and aerial work vehicle boom angle measurement, medical equipment, mining machinery, oil drilling equipment, dams, buildings, bridge angle measurement and other scenarios with high requirements on voltage signal output stability. It can ensure stable and reliable voltage output and can adapt to various working conditions, especially harsh field environments with complex electromagnetic environments. After rigorous testing and inspection, the present invention can achieve good results.

[0093] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A voltage output stabilizing device for an intelligent sensor, characterized in that: include: Power module: used to provide stable power to the entire device and realize over-current protection, EMI protection and reverse connection protection of the power supply; Accelerometer and microcontroller module: including an accelerometer and a microcontroller that communicate with each other to realize acceleration signal acquisition and data processing, operational amplifier power supply control, and voltage output control; DAC output voltage regulator circuit module: including an operational amplifier connected to the microcontroller to output voltage signals as well as EMI protection, reverse connection protection and overcurrent protection; Output self-test module: connected to the DAC output voltage stabilization circuit module and the microcontroller respectively to sample the output voltage signal; Operational amplifier power supply control module: connected to the DAC output voltage stabilizing circuit module and the microcontroller respectively, to control the power switch of the DAC output voltage stabilizing circuit module.

2. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: The power module includes an EMI and anti-reverse connection protection circuit, a DC-DC power supply circuit and an LDO circuit which are arranged in sequence. The EMI and anti-reverse connection protection circuit is connected to an external power supply, and overcurrent protection, EMI protection and anti-reverse connection protection are achieved through a first fuse, a first varistor and a first transient voltage suppression diode.

3. The voltage output stabilizing device of a smart sensor according to claim 2, characterized in that: The EMI and reverse connection protection circuit also decouples the power input through a filter capacitor, filters out high-frequency noise in the external power supply, and smoothes the input voltage of the external power supply.

4. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: The DAC output voltage stabilization circuit module also includes a preliminary voltage regulation submodule, a high-frequency noise filtering submodule, a feedback network submodule, an EMI protection / reverse connection / current protection submodule and a signal regulation submodule. Pin No. 1 IN+ of the operational amplifier is connected to the DAC port of the microcontroller MCU through the signal regulation submodule, Pin No. 2 V- is grounded, Pin No. 3 IN- and Pin No. 4 OUT are grounded through the feedback network submodule, Pin No. 5 V+ is connected to the output end of the operational amplifier power supply control module through the preliminary voltage regulation submodule, and Pin No. 4 OUT is connected to the output self-test module and the device output end after passing through the EMI protection / reverse connection / current protection submodule, and the high-frequency noise filtering submodule is arranged between Pin No. 5 V+ and the preliminary voltage regulation submodule.

5. The voltage output stabilizing device of an intelligent sensor according to claim 4, characterized in that: The signal regulation submodule is composed of two resistors connected in parallel, the preliminary voltage regulation submodule is a step-down resistor, which is arranged between pin 5 V+ and the output end of the operational amplifier power supply control module, the feedback network submodule includes a first resistor and a second resistor connected in series, the pin 3 IN- is grounded through the first resistor, and the pin 4 OUT is grounded through the first resistor and the second resistor connected in series, the EMI protection / reverse connection / current protection submodule includes a TVS diode arranged between pin 4 OUT and ground, a varistor arranged between the output end of the device and ground, and a second fuse arranged between pin 4 OUT and the output end of the device, and the high-frequency noise filtering submodule includes two filter capacitors arranged in parallel.

6. The voltage output stabilizing device of an intelligent sensor according to claim 4, characterized in that: The output self-test module includes a voltage divider module and a clamping diode. The microcontroller is connected to the analog ground through the voltage divider module. The voltage divider module is composed of a third resistor and a fourth resistor that are connected in series and have equal resistance values. The output end of the device is connected between the third resistor and the fourth resistor, and is connected to the analog ground through the clamping diode.

7. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: The operational amplifier power supply control module includes a bias network, a transistor and a field effect transistor. The bias network is composed of a fifth resistor, a sixth resistor and a seventh resistor. The base of the transistor is connected to the GPIO port of the microcontroller through the sixth resistor and is grounded through the fifth resistor. The emitter of the transistor is grounded. The collector of the transistor is connected to the gate of the field effect transistor through the seventh resistor. The source of the field effect transistor is connected to the power module. The drain of the field effect transistor is connected to the operational amplifier as the power supply end of the DAC output voltage stabilization circuit module.

8. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: The voltage output stabilizing device also includes a working indicator light circuit module connected to the microcontroller, wherein the working indicator light circuit module includes two LED lights of different colors and a matching driving element to indicate different working states.

9. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: The voltage output stabilizing device also includes a zeroing button circuit module connected to the microcontroller, the zeroing button circuit module includes a physical button, a pull-up resistor, a current limiting resistor, a second varistor and a second transient voltage suppression diode, one end of the physical button is grounded, and the other end is connected to the zeroing port of the microcontroller through the current limiting resistor, one end of the pull-up resistor is connected to the power module, and the other end is connected to the zeroing port of the microcontroller, one end of the second varistor is connected to the zeroing port of the microcontroller, and the other end is grounded, and one end of the second transient voltage suppression diode is connected to the zeroing port of the microcontroller, and the other end is grounded.

10. The voltage output stabilizing device of an intelligent sensor according to claim 1, characterized in that: When the device is working normally, the accelerometer sends the detected acceleration information to the microcontroller, the microcontroller processes the data to obtain the angle data, and outputs the corresponding voltage signal through the DAC output voltage stabilization circuit module according to the corresponding linear relationship. In this process, the output self-test module divides the output voltage signal in real time and samples it to the microcontroller. The microcontroller compares the sampling result with the set value or range to determine whether the output voltage signal is normal. If it is abnormal, the operational amplifier power supply control module is controlled to stop supplying power to the operational amplifier of the DAC output voltage stabilization circuit module, and the reference voltage signal output of the operational amplifier is turned off. The microcontroller also issues an abnormal alarm through the working indicator light circuit module.

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