A kind of acquisition circuit and liquid level sensor

Abstract

The utility model discloses an acquisition circuit and liquid level sensor, relate to signal acquisition technical field. The acquisition circuit includes first resistance, second resistance, first electric capacity, second electric capacity and third electric capacity, the first end of first resistance is used to receive exciting signal, the second end of first resistance and the first end of second resistance electric connection, the second end of second resistance and the first end of first electric capacity electric connection, the second end of first electric capacity and the first end of second electric capacity electric connection, the connecting node between first electric capacity and second electric capacity is ground setting, the second end of second electric capacity is used for accessing the first end of sensor unit, the connecting node between first resistance and second resistance and one end of third electric capacity electric connection, the second end of third electric capacity is used for accessing the second end of sensor unit, wherein, the connecting node between second resistance and first electric capacity is used for output sampling signal. The acquisition circuit only constitutes by a small amount of resistance, electric capacity device, does not need complex special chip or analog front end circuit, and the overall structure is simple, reduces hardware cost, and improves the economy of mass production.

Description

Technical Field

[0001] This utility model relates to the field of signal acquisition technology, and in particular to an acquisition circuit and a liquid level sensor. Background Technology

[0002] With the development of automotive electronics technology, the application and types of sensor technology are also diversifying. Among them, the coolant level sensor is a common type of automotive electronic sensor. Its function is to convert the change in liquid level into an electrical signal, which is then provided to the controller (Microcontroller Unit; MCU) to determine whether the liquid level is below a set value.

[0003] Currently, there are various analog acquisition circuits for coolant level sensors in related technologies. The analog acquisition circuits for coolant level sensors used in Zone Control Unit (ZCU) platforms are complex and mostly suffer from high cost and slow response speed.

[0004] Therefore, there is an urgent need for a data acquisition circuit and liquid level sensor that is simple in circuit structure, low in cost, and has sufficient sampling accuracy. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a data acquisition circuit and a liquid level sensor. The data acquisition circuit consists of only a small number of resistors and capacitors, and does not require complex dedicated chips or analog front-end circuits. The overall structure is simple, which reduces hardware costs and improves the economics of mass production. At the same time, it has the advantage of high sampling accuracy.

[0006] This utility model discloses a data acquisition circuit, including a first resistor, a second resistor, a first capacitor, a second capacitor, and a third capacitor. A first terminal of the first resistor is used to receive an excitation signal. A second terminal of the first resistor is electrically connected to a first terminal of the second resistor. A second terminal of the second resistor is electrically connected to a first terminal of the first capacitor. A second terminal of the first capacitor is electrically connected to a first terminal of the second capacitor. The connection node between the first capacitor and the second capacitor is grounded. A second terminal of the second capacitor is used to connect to a first terminal of a sensor unit. The connection node between the first resistor and the second resistor is electrically connected to one terminal of the third capacitor. The other terminal of the third capacitor is used to connect to a second terminal of the sensor unit. The connection node between the second resistor and the first capacitor is used to output a sampling signal.

[0007] Furthermore, the excitation signal is a 5V PWM signal.

[0008] Furthermore, the sampling signal is a voltage signal.

[0009] Furthermore, the acquisition circuit also includes a control module, one end of which is electrically connected to the first end of the first resistor to output the excitation signal, and the other end of which is electrically connected to the connection node between the second resistor and the first capacitor to receive the sampling signal.

[0010] Furthermore, the capacitance value of the first capacitor is 1 nanofarad.

[0011] Furthermore, the capacitance of the second capacitor is 1 microfarad.

[0012] Furthermore, the capacitance value of the third capacitor is 220 nanofarads.

[0013] Furthermore, the resistance values ​​of both the first resistor and the second resistor are 46.4kΩ.

[0014] This utility model embodiment also discloses a liquid level sensor, including a sensor unit and a data acquisition circuit as described above.

[0015] Furthermore, the sensor unit includes a third resistor, a fourth resistor, and a fifth capacitor. One end of the third resistor is electrically connected to the fifth capacitor, the other end of the third resistor is electrically connected to one end of the fourth resistor, the other end of the fourth resistor is electrically connected to the fifth capacitor, the connection node between the fifth capacitor and the fourth resistor is electrically connected to the third capacitor, and the connection node between the fourth resistor and the third resistor is electrically connected to the second capacitor.

[0016] The acquisition circuit provided by this utility model has the following beneficial effects, including but not limited to:

[0017] 1) This acquisition circuit consists of only a small number of resistors and capacitors, and does not require complex dedicated chips or analog front-end circuits. The overall structure is simple, which reduces hardware costs and improves the economics of mass production.

[0018] 2) In this acquisition circuit, the 5V PWM signal output by the control module is used as the excitation source to drive the sensor unit to work. The sensor exhibits different resistance and capacitance characteristics at different liquid levels. After being modulated by the circuit, it is converted into different voltage signals, so that the MCU can quickly distinguish the liquid level status through the ADC port, avoiding the complexity of traditional constant current source / analog signal source circuits.

[0019] 3) In this acquisition circuit, the voltage response can be completed within one PWM cycle through PWM excitation and RC network. The response speed is faster than that of traditional analog acquisition circuits, which can meet the real-time requirements of automotive coolant level, etc. The parameters (resistance and capacitance values) of each resistor and capacitor in the circuit can be flexibly configured, thereby further improving the detection accuracy. Attached Figure Description

[0020] This specification will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0021] Figure 1 A circuit diagram of the acquisition circuit provided in an embodiment of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the liquid level sensor provided in an embodiment of the present invention. Detailed Implementation

[0023] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0025] Figure 1 This is a schematic diagram of the acquisition circuit provided in an embodiment of the present utility model. Figure 1 As shown, this utility model provides a data acquisition circuit, which includes a first resistor (i.e., Figure 1 R53 shown), the second resistor (i.e. Figure 1 R54 shown), the first capacitor (i.e. Figure 1 C87 shown), the second capacitor (i.e. Figure 1 The C85 shown is the third capacitor (i.e., Figure 1 As shown in C86); the first terminal of the first resistor is used to receive the excitation signal (i.e. Figure 1As shown in the MCU_OUT_SPARE_SENSOR diagram, the second terminal of the first resistor is electrically connected to the first terminal of the second resistor, the second terminal of the second resistor is electrically connected to the first terminal of the first capacitor, the second terminal of the first capacitor is electrically connected to the first terminal of the second capacitor, the connection node between the first and second capacitors is grounded, the second terminal of the second capacitor is used to connect to the first terminal of the sensor unit, the connection node between the first and second resistors is electrically connected to one terminal of the third capacitor, and the other terminal of the third capacitor is used to connect to the second terminal of the sensor unit; wherein, the connection node between the second resistor and the first capacitor is used to output the sampling signal (i.e., Figure 1 (as shown in MCU_IN_SPARE_SENSOR).

[0026] It should be noted that the excitation signal in this embodiment refers to the input signal used to drive the acquisition circuit.

[0027] It is worth noting that the acquisition circuit consists of only a small number of resistors and capacitors, and does not require complex dedicated chips or analog front-end circuits. The overall structure is simple, which reduces hardware costs and improves the economics of mass production.

[0028] In some embodiments, the excitation signal is a 5V PWM signal.

[0029] It is worth noting that in this acquisition circuit, the 5V PWM signal output by the control module serves as the excitation source to drive the sensor unit. The sensor exhibits different resistance and capacitance characteristics at different liquid levels, which are converted into different voltage signals after being modulated by the circuit. This allows the MCU to quickly distinguish the liquid level status through the ADC port, avoiding the complexity of traditional constant current source / analog signal source circuits.

[0030] It is also worth noting that by using a 5V PWM signal as the excitation signal, the corresponding voltage response can be generated in one PWM cycle, which is suitable for real-time detection scenarios where the liquid level changes rapidly.

[0031] In some embodiments, the sampling signal is a voltage signal.

[0032] It is worth noting that after the sampling signal is a voltage signal, the control module can directly acquire it through the ADC port without the need for additional current-to-voltage conversion circuits or complex signal conditioning, thereby simplifying the system design and further reducing the structural complexity of the acquisition circuit.

[0033] In some embodiments, the acquisition circuit further includes a control module, one end of which is electrically connected to the first end of the first resistor for outputting an excitation signal, and the other end of which is electrically connected to the connection node between the second resistor and the first capacitor for receiving a sampling signal.

[0034] It is worth noting that the control module can be a microcontroller or other digital control unit. It not only serves as the output source of the excitation signal, but also as the receiving and processing unit of the sampling signal, realizing the core control and data processing functions of the liquid level acquisition circuit, thereby improving the real-time performance, accuracy and reliability of liquid level detection.

[0035] Optionally, the capacitance of the first capacitor is 1 nanofarad.

[0036] Optionally, the capacitance of the second capacitor is 1 microfarad.

[0037] Optionally, the capacitance of the third capacitor is 220 nanofarads.

[0038] Optionally, the resistance values ​​of both the first resistor and the second resistor are 46.4kΩ.

[0039] Specifically, in this embodiment, the parameters of the first resistor, the second resistor, the first capacitor, the second capacitor, and the third capacitor can be flexibly determined according to the specific implementation environment, and this embodiment does not limit their specific values. After applying the above parameters to the coolant level sensor of the automotive ZCU platform, the RC network parameters are optimized, which enables the sampling signal to respond stably within one PWM cycle, making it suitable for scenarios with rapid changes in liquid level; at the same time, the reasonable configuration of the capacitor and resistor can effectively suppress noise and interference, and improve the reliability of the sampling voltage signal.

[0040] More importantly, the acquisition circuit using the above parameters determines the liquid level as empty when the MCU detects a value greater than 2V for MCU_IN_SPARE_SENSOR, and as full when the MCU detects a value less than 1.5V. Therefore, the acquisition circuit using these parameters exhibits significant differentiation in liquid level determination, enabling rapid and accurate identification of the liquid level status. This improves the accuracy and reliability of liquid level detection, meeting the requirements of real-time monitoring applications such as automotive coolant levels.

[0041] Figure 2 This is a schematic diagram of the structure of the liquid level sensor provided in the embodiment of this utility model, as shown below. Figure 2 As shown in the figure, this utility model embodiment also discloses a liquid level sensor, including a sensor unit; and a data acquisition circuit as described above.

[0042] In some embodiments, the sensor unit includes a third resistor (i.e., Figure 2 The RX shown), the fourth resistor (i.e. Figure 2 R0 shown) and the fifth capacitor (i.e. Figure 2As shown in CX), one end of the third resistor is electrically connected to the fifth capacitor, the other end of the third resistor is electrically connected to one end of the fourth resistor, the other end of the fourth resistor is electrically connected to the fifth capacitor, the connection node between the fifth capacitor and the fourth resistor is electrically connected to the third capacitor, and the connection node between the fourth resistor and the third resistor is electrically connected to the second capacitor.

[0043] It is worth noting that the liquid level sensor incorporates this acquisition circuit and possesses all its beneficial effects.

[0044] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0045] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0046] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention shown herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0047] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0048] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0049] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0050] The above description of the embodiments shown in this utility model (including the content in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments of the utility model, and such modifications will be within the spirit and scope of the utility model.

[0051] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A data acquisition circuit, characterized in that, It includes a first resistor, a second resistor, a first capacitor, a second capacitor, and a third capacitor; The first end of the first resistor is used to receive an excitation signal. The second end of the first resistor is electrically connected to the first end of the second resistor. The second end of the second resistor is electrically connected to the first end of the first capacitor. The second end of the first capacitor is electrically connected to the first end of the second capacitor. The connection node between the first capacitor and the second capacitor is grounded. The second end of the second capacitor is used to connect to the first end of the sensor unit. The connection node between the first resistor and the second resistor is electrically connected to one end of the third capacitor. The other end of the third capacitor is used to connect to the second end of the sensor unit. The connection node between the second resistor and the first capacitor is used to output a sampling signal.

2. The acquisition circuit according to claim 1, characterized in that, The excitation signal is a 5V PWM signal.

3. The acquisition circuit according to claim 1, characterized in that, The sampled signal is a voltage signal.

4. The acquisition circuit according to any one of claims 1-3, characterized in that, The acquisition circuit further includes a control module. One end of the control module is electrically connected to the first end of the first resistor to output the excitation signal, and the other end of the control module is electrically connected to the connection node between the second resistor and the first capacitor to receive the sampling signal.

5. The acquisition circuit according to claim 1, characterized in that, The capacitance of the first capacitor is 1 nanofarad.

6. The acquisition circuit according to claim 1, characterized in that, The capacitance of the second capacitor is 1 microfarad.

7. The acquisition circuit according to claim 1, characterized in that, The capacitance of the third capacitor is 220 nanofarads.

8. The acquisition circuit according to claim 1, characterized in that, The resistance values ​​of both the first resistor and the second resistor are 46.4kΩ.

9. A liquid level sensor, characterized in that, include: Sensor unit; as well as The acquisition circuit as described in any one of claims 1-8.

10. The liquid level sensor according to claim 9, characterized in that, The sensor unit includes a third resistor, a fourth resistor, and a fifth capacitor. One end of the third resistor is electrically connected to the fifth capacitor, and the other end of the third resistor is electrically connected to one end of the fourth resistor. The other end of the fourth resistor is electrically connected to the fifth capacitor. The connection node between the fifth capacitor and the fourth resistor is electrically connected to the third capacitor, and the connection node between the fourth resistor and the third resistor is electrically connected to the second capacitor.

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