Wide-range capacitive continuous liquid level sensor

Abstract

The utility model relates to a wide-range capacitive continuous liquid level sensor which comprises a first conductive electrode and a second conductive electrode corresponding to the first conductive electrode, the liquid level sensor is connected into a circuit through the first conductive electrode and the second conductive electrode, and the first conductive electrode and the second conductive electrode are installed and placed in liquid through a base. The distance between the first conductive electrode and the second conductive electrode at the same position in any height plane is equal, so that the capacitance value is linearly increased or decreased when the liquid level is linearly increased or decreased. The stainless steel cylinder symmetrically forms the cylindrical PCB soft board which is bent and rolled into a smooth and uniform surface, and the two electrodes form the same distance between two circumferential surfaces in a plane of any height, so that when the medium is linearly increased or decreased, the capacitance value of the capacitor formed by the PCB soft board, the stainless steel cylinder and the medium is linearly increased or decreased, and the capacitance value of the capacitor is increased or decreased. The continuous liquid level change of the medium can be accurately detected, and high-precision application is brought to wide-range capacitive continuous liquid level detection.

Description

Technical Field

[0001] The utility model relates to the field of liquid level sensors, in particular to a large-range capacitive continuous liquid level sensor. Background Art

[0002] Traditional large-scale capacitive cylindrical continuous liquid level sensors consist of two electrodes formed by a copper sheet and stainless steel. However, when the copper sheet is too thick, it is difficult to machine it into a smooth and uniform cylinder because it easily produces concave or convex points during the bending process. This prevents the stainless steel cylinder and the copper sheet from forming an equidistant cylindrical surface. This results in unequal spacing between the stainless steel and copper circles at each height, making it difficult to form a corresponding linear relationship. When the medium (water, oil, etc.) between the copper and stainless steel electrodes increases or decreases linearly, the capacitance formed by the copper, stainless steel, and medium will not increase or decrease linearly. Similarly, when the copper sheet is too thin, it will not form a linearly increasing or decreasing capacitance value. This makes it difficult to apply high-precision detection of continuous liquid level changes.

[0003] Chinese patent publication number CN215893734U discloses a non-contact liquid level sensor, which includes a plastic housing, a PCB driver board located within the plastic housing, and a sensing copper sheet assembly located on one side of the plastic housing; the sensing copper sheet assembly is connected to the PCB driver board via welding holes provided in the plastic housing; a capacitive touch chip is integrated on the PCB driver board, an output line is welded to the PCB driver board, the welding end of the output line is encapsulated within the plastic housing, and the distal end is a terminal; a pair of mounting protrusions are spaced apart on one side of the plastic housing, and a through-hole is formed between the sensing copper sheet assembly and the pair of mounting protrusions. This non-contact liquid level sensor has excellent features such as a simple and compact structure, stable functions, high detection accuracy, convenient installation, and adjustable accuracy, and has strong practical value and application value. The liquid level sensor described in this patent cannot ensure that the distance between the two sets of electrodes at any relative height plane is the same, resulting in the inability to achieve a linear increase or decrease in capacitance value. Utility Model Content

[0004] The technical problem to be solved by the present invention is that the spacing between the stainless steel circle and the copper circle at each height is unequal, making it difficult to form a corresponding linear relationship. When the medium (water, oil, etc.) between the copper and stainless steel electrodes increases or decreases linearly, the capacitor formed by the copper, stainless steel, and medium cannot achieve a linear increase or decrease in capacitance. Similarly, if the copper sheet is too thin, it is also impossible to form a linear increase or decrease in capacitance. This makes it difficult to accurately detect continuous liquid level changes in the medium. To address the above-mentioned shortcomings of the existing technology, a large-scale capacitive continuous liquid level sensor is provided.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A large-scale capacitive continuous liquid level sensor is constructed, comprising a first conductive electrode and a second conductive electrode corresponding to the first conductive electrode. The liquid level sensor is connected to a circuit via the first conductive electrode and the second conductive electrode. The first and second conductive electrodes are mounted via a base and placed in liquid. The distance between the first and second conductive electrodes at the same position in any height plane is equal, so that when the liquid level increases or decreases linearly, the capacitance value increases or decreases linearly.

[0007] Preferably, the first conductive electrode and the second conductive electrode are both cylindrical and are concentrically arranged so that the distance between the two circumferential surfaces in any height plane is the same.

[0008] Preferably, an insulating tube is provided outside the second conductive electrode, a liquid level area is formed between the first conductive electrode and the insulating tube, and a liquid level area is formed inside the second conductive electrode.

[0009] Preferably, the first conductive electrode is a stainless steel sleeve, and the first conductive electrode is a PCB soft board.

[0010] Preferably, the PCB flexible board is bent and rolled into a cylindrical shape with a smooth surface.

[0011] Preferably, a connecting thread is provided at the lower end of the base, and the liquid level sensor is installed through the connecting thread.

[0012] The present invention has the beneficial effect of using a PCB flexible board, which is bent and rolled into a cylindrical shape with a smooth and uniform surface, as the other electrode is symmetrically formed with the stainless steel cylinder. This ensures that the distance between the two circumferential surfaces of the two sets of electrodes is the same in any plane at any height. As a result, the capacitance value of the capacitor formed by the PCB flexible board cylinder, the stainless steel cylinder, and the medium (water, oil, etc.) can linearly increase or decrease when the medium increases or decreases linearly, thereby accurately detecting the continuous liquid level change of the medium, providing a feasible and high-precision application design for large-scale capacitive continuous liquid level detection. When the capacitor system containing the PCB flexible board cylinder, the stainless steel cylinder, and the medium (water, oil, etc.) is connected to a capacitive-resistive charge-discharge circuit, when the liquid level rises or falls linearly, the capacitance value increases or decreases accordingly, which is related to the increase or decrease in the charge and discharge time of the charge and discharge circuit. The processor uses an algorithm to associate the RMS value of the charge and discharge time within a cycle of the charge and discharge circuit with the liquid level, thereby achieving the precise continuous liquid level detection function of the large-scale capacitive cylindrical continuous liquid level sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0014] Figure 1 This is a structural diagram of a liquid level sensor according to a preferred embodiment of the present invention;

[0015] Figure 2 This is a schematic top view of the liquid level sensor according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] A large-range capacitive continuous liquid level sensor according to a preferred embodiment of the present invention; Figure 1-2 As shown, the sensor comprises a base 10 and a stainless steel sleeve 20 positioned above the base. A PCB 40 is housed within the stainless steel sleeve, which is then protected by an insulating sleeve 30. A liquid level zone 50 is formed within the PCB and between the insulating sleeve and the stainless steel sleeve. When the stainless steel sleeve and PCB are connected to a circuit, the liquid level can be measured based on the circuit state when liquid enters the liquid level zone. A connecting thread 60 is provided at the lower end of the base 10, allowing the liquid level sensor to be mounted via the connecting thread, making installation more convenient.

[0018] Specifically, to ensure that the capacitance increases or decreases linearly with the rise or fall of the liquid level, the stainless steel sleeve 20 and the PCB 40 should be concentrically arranged so that the spacing between the two circumferences is the same in any height plane. This allows the capacitance formed by the PCB, stainless steel sleeve, and dielectric to increase or decrease linearly as the dielectric linearly increases or decreases, thereby accurately detecting the continuous liquid level changes of the dielectric, providing a feasible and high-precision application design for large-scale capacitive continuous liquid level detection. Since the stainless steel sleeve is cylindrical, it serves as one set of electrodes, and the other set of electrodes is formed by bending the PCB into a smooth and uniform cylindrical shape. The cylindrical PCB and the stainless steel sleeve are concentrically arranged so that the distance between the two circumferences of the PCB cylinder and the stainless steel cylinder is equal in any height plane. It should be noted that the cylindrical design of the two sets of conductive electrodes is the optimal solution for this utility model, but other shapes can also be designed. When the distance between the two circumferences of the two sets of conductive electrodes is equal in any height plane, the capacitance can be linearly changed with the rise or fall of the liquid level. This capacitive system, consisting of a PCB cylinder, a stainless steel cylinder, and a medium (water, oil, etc.), is connected to a capacitive-resistive charge-discharge circuit. As the liquid level rises or falls linearly, the capacitance correspondingly increases or decreases, leading to an increase or decrease in the circuit's charge and discharge time. A processor then uses an algorithm to correlate the RMS value of the circuit's charge and discharge time within a cycle with the liquid level, achieving precise and continuous liquid level detection for the large-scale capacitive cylindrical continuous liquid level sensor.

[0019] It should be understood that the present invention is described by way of certain embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the guidance of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A large-scale capacitive continuous liquid level sensor, comprising a first conductive electrode and a second conductive electrode corresponding to the first conductive electrode, wherein the liquid level sensor is connected to a circuit via the first conductive electrode and the second conductive electrode, wherein the first conductive electrode and the second conductive electrode are mounted on a base and placed in the liquid, characterized in that: The distance between the first conductive electrode and the second conductive electrode at the same position in any height plane is equal, so that when the liquid level increases or decreases linearly, the capacitance value increases or decreases linearly.

2. The liquid level sensor according to claim 1, characterized in that: The first conductive electrode and the second conductive electrode are both cylindrical and concentrically arranged so that the distance between the two circumferential surfaces in any height plane is the same.

3. The liquid level sensor according to claim 2, characterized in that: An insulating tube is provided outside the second conductive electrode. A liquid level area is formed between the first conductive electrode and the insulating tube, and a liquid level area is formed inside the second conductive electrode.

4. The liquid level sensor according to claim 1, characterized in that: The first conductive electrode is a stainless steel sleeve, and the first conductive electrode is a PCB soft board.

5. The liquid level sensor according to claim 4, characterized in that: The PCB soft board is bent and rolled into a cylindrical shape with a smooth surface.

6. The liquid level sensor according to claim 1, characterized in that: The lower end of the base is provided with a connecting thread, and the liquid level sensor is installed through the connecting thread.

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