Capacitive sensor

Abstract

The utility model provides a capacitance type sensor, comprising a housing, a tail cover, a detection induction disc, a main control substrate and an induction button, the detection induction disc and the induction button are electrically connected on the main control substrate, the main control substrate, the detection induction disc and the induction button are all accommodated in the internal space of the housing, the tail cover is connected with the housing, and the tail cover is connected with the main control substrate. The shell or the tail cover is provided with a touch area corresponding to the induction key, the touch area can be touched to trigger the induction key, the detection induction disc is used for detecting the capacitance change around the shell, and the tail cover is used for sealing the internal space of the shell. According to the capacitive sensor, the sensing key is arranged in the shell, control over the sensing key is achieved in a touch control mode, water, steam, powder and the like cannot enter the shell through the tail cover, interference and corrosion of the water, the steam, the powder and the like to a measuring circuit are avoided, the service life of the capacitive sensor is prolonged, and the stability of the capacitive sensor is improved.

Description

Technical Field

[0001] This utility model relates to the field of feed sensor technology, and in particular to a capacitive sensor. Background Technology

[0002] In existing capacitive sensors, many products integrate knobs for adjusting and controlling the sensor in the tail plug location or on the side rear of the housing. Knob-type products either expose the potentiometer knob directly to the air or have a silicone plug behind it. While these designs offer operational convenience, they have significant drawbacks in terms of waterproofing and dustproofing: the connection between the knob and the tail plug lacks sufficient sealing, easily allowing moisture and dust to intrude. In harsh operating environments, especially those similar to aquaculture environments, common pollutants such as ammonia, disinfectant vapors, and organic dust can enter the internal circuitry through the knob-tail plug connection, causing significant corrosion and interference. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a capacitive sensor, which aims to solve the problem in the prior art that in harsh operating environments, especially in environments similar to aquaculture, common ammonia, disinfectant vapors, and organic dust enter the internal circuit through the connection between the knob and the tail plug or the outer shell, causing strong corrosion and interference to the circuit.

[0004] This utility model provides a capacitive sensor, including a housing, a tail cap, a detection sensor disk, a main control board, and a sensing button. The detection sensor disk and the sensing button are electrically connected to the main control board. The housing has a hollow structure, and the main control board, the detection sensor disk, and the sensing button are all housed within the internal space of the housing. The tail cap is connected to the housing. The housing or the tail cap has a touch area corresponding to the sensing button. The touch area can be touched to trigger the sensing button. The detection sensor disk is used to detect capacitance changes around the housing, and the tail cap is used to seal the internal space of the housing.

[0005] Furthermore, it also includes an indicator light, which is electrically connected to the main control board. The indicator light is located on the side of the tail cover facing the main control board and is used to display the operating status of the capacitive sensor.

[0006] Furthermore, a light viewing hole is provided on the tail cover, through which the light from the indicator light can pass.

[0007] Furthermore, the main control board is connected to the outside via wires, and a wire protector is provided on the tail cover. The wires are led out from the wire protector, and the wire protector is attached to the periphery of the wires to seal the gap between the wire protector and the wires.

[0008] Furthermore, a calibration sensor disk is provided on the main control board.

[0009] Furthermore, a temperature sensor is provided on the main control board.

[0010] Furthermore, the sensing button is located on the inner peripheral wall of the housing near the tail cap, and the touch area is correspondingly located on the outer peripheral wall of the housing at a position corresponding to the sensing button.

[0011] Furthermore, the sensing button is located on the side of the tail cover close to the main control board, and the side of the tail cover away from the main control board is provided with a touch area corresponding to the sensing button.

[0012] Furthermore, it also includes a waterproof head, one side of which is attached to the end of the housing away from the tail cap, and the other side is attached to the outer wall of the object to be tested. The waterproof head is used to seal the gap between the waterproof head and the housing, as well as the gap between the waterproof head and the object to be tested.

[0013] Beneficial Effects: This utility model provides a capacitive sensor, including a housing, a tail cap, a detection sensor disk, a main control board, and a sensing button. The detection sensor disk and the sensing button are electrically connected to the main control board. The housing has a hollow structure, and the main control board, the detection sensor disk, and the sensing button are all housed within the internal space of the housing. The tail cap is connected to the housing, and the housing or tail cap has a touch area corresponding to the sensing button. The touch area can be touched to trigger the sensing button. The detection sensor disk is used to detect capacitance changes around the housing, and the tail cap is used to seal the internal space of the housing. Because the sensing button of this application is located inside the housing, and the sensing button is controlled by touch, water, vapor, powder, etc., cannot enter the interior of the housing, avoiding interference and corrosion of the measurement circuit by water, vapor, powder, etc., thus enhancing the working life and stability of the capacitive sensor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the capacitive sensor of this utility model;

[0015] Figure 2 Internal schematic diagram of the capacitive sensor of this utility model;

[0016] Figure 3 An internal schematic diagram of the capacitive sensor of this utility model from another perspective;

[0017] Figure 4 This is a schematic diagram of the exposed knob on the tail cover in the prior art.

[0018] In the diagram: 1. Outer shell; 2. Tail cover; 21. Touch area; 22. Lamp viewing hole; 23. Cable sheath; 3. Detection sensor plate; 4. Main control board; 41. Calibration sensor plate; 42. Temperature sensor; 43. Integrated chip; 5. Sensor button; 6. Indicator light; 7. Wire; 8. Waterproof head; 9. Pipe; 10. Knob. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0020] Please see Figures 1 to 3 This utility model provides a capacitive sensor, including a housing 1, a tail cover 2, a detection sensor disk 3, a main control board 4, and a sensing button 5. The detection sensor disk 3 and the sensing button 5 are electrically connected to the main control board 4. The housing 1 has a hollow structure, and the main control board 4, the detection sensor disk 3, and the sensing button 5 are all housed within the internal space of the housing 1. The tail cover 2 is connected to the housing 1. The housing 1 or the tail cover 2 has a touch area 21 corresponding to the sensing button 5. The touch area 21 can be touched to trigger the sensing button 5. The detection sensor disk 3 is used to detect capacitance changes around the housing 1, and the tail cover 2 is used to seal the internal space of the housing 1.

[0021] The capacitive sensor in this application is suitable for aquaculture environments with high humidity and frequent disinfection. It is commonly installed on the feed conveying pipe 9 to detect the presence of feed, so that automated equipment can deliver feed in a timely manner.

[0022] Reference Figure 4In existing technologies, the working principle of capacitive feed sensors capable of non-contact feed detection is as follows: An analog circuit is used to induce high-frequency oscillation of the capacitance formed by the sensing disk and surrounding materials. The voltage after rectification and amplification is compared with a threshold voltage to determine the presence of the measured substance. Because the sensing disk and all surrounding materials have capacitance, and this capacitance is related to the material, quantity, distance, temperature, and humidity of the surrounding materials, the sensor's installation environment is crucial. For example, the material and thickness of the mounting bracket, the diameter, material, and thickness of the feed pipe 9 are all closely related. However, the surrounding materials (including the feed pipe 9 and mounting bracket) vary from place to place, so the threshold voltage cannot be fixed. An adjuster must be used to adjust the threshold voltage so that the sensor can adapt to different operating environments. Typically, the knob 10 is exposed on the side and rear of the tail cover 2 or the outer casing 1 for easy adjustment. It is precisely because the regulator must be adjusted by knob 10 that the main control board 4 inside the outer shell 1 cannot be completely sealed from the outside. Ammonia, disinfectant vapor, and organic dust commonly found in the breeding environment enter the interior through the connection between knob 10 and tail cap 2 or outer shell 1, corroding the main control board 4.

[0023] Specifically, the main control substrate 4 in this application is a printed circuit board and is equipped with an integrated chip 43. The integrated chip 43 is an integrated microcontroller with at least three capacitance measurement pins and one digital signal pin. The detection sensing disk 3 is a circular printed circuit board with copper foil, the sensing button 5 is a circular metal disk, the outer shell 1 is a cylindrical insulating shell with only a rear end opening, and the tail cover 2 is an insulating cover. The integrated chip 43 is directly soldered onto the main control substrate 4. The electrical signal of the detection sensing disk 3 is soldered and fixed through the sensing disk soldering hole into the sensing disk soldering head, and connected to one of the capacitance measurement pins of the integrated chip 43 to form a capacitance measurement circuit for the object under test. Exemplarily, the sensing button 5 can be set on the inner peripheral wall of the outer shell 1 near the tail cover 2, and correspondingly, the touch area 21 is set on the outer peripheral wall of the outer shell 1 at a position corresponding to the sensing button 5. Preferably, the sensing button 5 is closely attached to the inner wall of the tail cover 2. When the tail cover 2 closes the outer shell 1, the sensing button 5 is located inside the outer shell 1. Correspondingly, the side of the tail cover 2 away from the main control board 4 is provided with a touch area 21 corresponding to the sensing button 5. The sensing button 5 is soldered to the sensing button 5 pad through the sensing button 5 connecting wire and connected to the third capacitance measurement pin of the integrated chip 43 to form a button sensing capacitance measurement circuit. The detection sensing disk 3 and the main control board 4 are fitted into the outer shell 1 together. The detection sensing disk 3 is closely attached to the front inner wall of the insulating material of the outer shell 1. The tail cover 2 covers the rear opening of the outer shell 1 and is fixed to the outer shell 1 with adhesive.

[0024] In this application, the main control board 4 continuously monitors the capacitance value of the sensing button 5. Once a significant change in the capacitance of the sensing button 5 is detected (usually because a person's finger approaches or touches the touch area 21), the circuit generates a signal to adjust the threshold voltage. When the finger is removed, the capacitance value returns to its original state, and the adjustment is complete.

[0025] In one feasible embodiment, an indicator light 6 is also included. The indicator light 6 is electrically connected to the main control board 4 and is located on the side of the tail cover 2 facing the main control board 4. The indicator light 6 is used to display the operating status of the capacitive sensor. In this embodiment, before the sensor is installed and put into formal use, the threshold voltage is adjusted by combining the touch-sensitive button 5 with the display of the indicator light 6. For example, when the touch-sensitive button 5 is triggered, the indicator light 6 lights up.

[0026] In one feasible embodiment, the tail cap 2 has a light viewing hole 22, through which light from the indicator light 6 can pass. The gap between the light viewing hole 22 and the indicator light 6 can be sealed by adhesive bonding. Since the seal between the light viewing hole 22 and the indicator light 6 is a static seal, its sealing effect is better than the dynamic seal at the connection between the knob 10 and the tail cap 2.

[0027] In one feasible implementation, the main control board 4 is connected to the outside via a wire 7. A cable sheath 23 is also provided on the tail cover 2. The wire 7 extends from the cable sheath 23, which is attached to the periphery of the wire 7 to seal the gap between the cable sheath 23 and the wire 7. One end of the wire 7 is directly soldered to the main control board 4, and the other end passes through the cable sheath 23 to obtain power and transmit signals from the outside.

[0028] In one feasible implementation, a calibration sensor disk 41 is provided on the main control substrate 4. The calibration sensor disk 41 is a circular copper foil, perpendicular to the surface of the detection sensor disk 3. The calibration sensor disk 41 is directly soldered onto the main control substrate 4 and connected to two of the capacitance measurement pins of the integrated chip 43 to form an environmental sensing capacitance measurement circuit. Since the surrounding materials (including feed pipes 9 and mounting brackets) at different sensor usage sites are not identical, the threshold voltage cannot be fixed. Therefore, the calibration sensor disk 41 needs to initialize the threshold voltage. In this implementation, the working principle of the calibration sensor disk 41 is as follows: During initialization, the integrated chip 43 records and saves the following capacitance values: WHC0 (no feed environment sensing capacitance value) formed by the sensor and the surrounding environment with the calibration sensor disk 41 when there is no feed, WC0 (no feed sensing capacitance value) formed by the surrounding materials with the detection sensor disk 3 when there is feed, YHC0 (feed environment sensing capacitance value) formed by the surrounding materials with the calibration sensor disk 41 when there is feed, and YC0 (feed sensing capacitance value) formed by the surrounding materials with the detection sensor disk 3 when there is feed. When the sensor is working, the integrated chip 43 measures in real time the environmental capacitance value HC between the surrounding environment and the calibration sensor disk 41, and the measured object capacitance value C formed by the surrounding material and the detection sensor disk 3. When C-HC < (WC0-WHC0)*(1+K%), it is judged that there is no feed, where K is the upper limit percentage for judging no feed. When C-HC > (YC0-YHC0)*(1-M%), it is judged that there is feed, where M is the lower limit percentage for judging feed. Since the presence or absence of feed is judged by the difference between the measured object capacitance value C and the environmental capacitance value WC, the influence of environmental changes on the measured object capacitance value C can be largely offset, thus greatly improving the accuracy of the judgment.

[0029] When it is not necessary to determine the quantity of the object being measured, a difference in capacitance between the presence and absence of feed can be estimated in the control program: D ≈ (Feed-present capacitance value YC0 - Feed-absence capacitance value WC0). When the measured object capacitance value C - the environmental capacitance value HC > (YC0 - YHC0) + D, it is determined that feed is present. This simplifies the sensor initialization process; only the environmental capacitance value WHC0 and the feed-absence capacitance value WC0 need to be recorded and saved. In this embodiment, the calibration sensor disk 41 is used to measure the environmental capacitance generated by surrounding materials in real time, compensating for the influence of surrounding materials on the measured object's capacitance, thus greatly improving the accuracy of the determination.

[0030] In one feasible implementation, a temperature sensor 42 is provided on the main control board 4. The temperature sensor 42 is a digital temperature sensor, which is directly soldered onto the main control board 4. The temperature digital signal line of the temperature sensor 42 is connected to the digital signal pin of the integrated chip 43 to form a temperature measurement circuit. Changes in temperature and humidity in the breeding environment also affect the sensing capacitance, causing instability in the sensor's detection. Therefore, the temperature sensor 42 is used for adjustment. In this embodiment, the specific working principle is as follows: when the working temperature range is large and the quantity of the measured object needs to be accurately measured, the initial values ​​of the sensing capacitance in the feedless environment (Tn_WHC0), feedless environment (Tn_WC0), fed environment (Tn_YHC0), and fed environment (Tn_YC0) are recorded and saved sequentially in a laboratory or constant temperature chamber at each temperature Tn0. When the sensor is working, the integrated chip 43 measures the temperature Tn, the real-time value of the ambient sensing capacitance T_HC, and the real-time value of the sensing capacitance of the measured object T_C in real time. Based on Tn, it finds the corresponding initial values ​​Tn_WHC0, Tn_WC0, Tn_YHC0, and Tn_YC0. When T_C - T_HC < (Tn_WC0 - Tn_WHC0) * (1 + Kt%), it is judged as "none," where Kt is the upper limit percentage for "none." When T_C - T_HC > (Tn_YC0 - Tn_YHC0) * (1 - Mt%), it is judged as "present," where Mt is the lower limit percentage for "present." In this embodiment, by setting the temperature sensor 42, a precise sensing capacitance temperature curve can be set to compensate for the deviation of the sensing capacitance caused by temperature changes, enabling the sensor to accurately and stably measure and judge the measured object within a wide temperature range.

[0031] In one feasible embodiment, a waterproof head 8 is also included. One side of the waterproof head 8 is attached to the end of the outer casing 1 away from the tail cap 2, and the other side is attached to the outer wall of the object to be tested. The waterproof head 8 is used to seal the gap between the waterproof head 8 and the outer casing 1, as well as the gap between the waterproof head 8 and the object to be tested. In an aquaculture environment, organic dust, moisture, and thin ice can enter the gap between the object to be tested (e.g., the feed conveying pipe 9) and the outer casing 1. Because the conductivity of moisture and thin ice is much higher than that of feed, only a small amount is needed to exceed the feed detection threshold. In this embodiment, due to the waterproof head 8, the gaps between the waterproof head 8 and the outer casing 1, as well as the gap between the waterproof head 8 and the pipe 9, are sealed. Furthermore, the detection sensor and the main control board are housed within the internal space of the outer casing 1 and sealed by the tail cap 2. This effectively prevents moisture and thin ice from appearing on the detection surface of the detection sensor, thereby improving the detection accuracy of the sensor.

[0032] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent elements of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A capacitive sensor, characterized in that: The device includes a housing (1), a tail cap (2), a detection sensor disk (3), a main control board (4), and a sensor button (5). The detection sensor disk (3) and the sensor button (5) are electrically connected to the main control board (4). The housing (1) has a hollow structure. The main control board (4), the detection sensor disk (3), and the sensor button (5) are all housed within the internal space of the housing (1). The tail cap (2) is connected to the housing (1). The housing (1) or the tail cap (2) has a touch area (21) corresponding to the sensor button (5). The touch area (21) can be touched to trigger the sensor button (5). The detection sensor disk (3) is used to detect capacitance changes around the housing (1). The tail cap (2) is used to seal the internal space of the housing (1).

2. The capacitive sensor according to claim 1, characterized in that: It also includes an indicator light (6), which is electrically connected to the main control board (4). The indicator light (6) is located on the side of the tail cover (2) facing the main control board (4). The indicator light (6) is used to display the operating status of the capacitive sensor.

3. The capacitive sensor according to claim 2, characterized in that: The tail cap (2) has a light viewing hole (22) that allows light from the indicator light (6) to pass through.

4. The capacitive sensor according to claim 1, characterized in that: The main control board (4) is connected to the outside via a wire (7). A wire protector (23) is also provided on the tail cover (2). The wire (7) is led out from the wire protector (23). The wire protector (23) is attached to the periphery of the wire (7) to seal the gap between the wire protector (23) and the wire (7).

5. The capacitive sensor according to claim 1, characterized in that: The main control board (4) is provided with a calibration sensor disk (41).

6. The capacitive sensor according to claim 1, characterized in that: A temperature sensor (42) is provided on the main control board (4).

7. The capacitive sensor according to claim 1, characterized in that: It also includes a waterproof head (8), one side of which is attached to the end of the housing (1) away from the tail cap (2), and the other side is attached to the outer wall of the object to be tested. The waterproof head (8) is used to seal the gap between the waterproof head (8) and the housing (1) and to seal the gap between the waterproof head (8) and the object to be tested.

8. The capacitive sensor according to claim 1, characterized in that: The sensing button (5) is located on the inner peripheral wall of the outer casing (1) near the tail cap (2), and the touch area (21) is correspondingly located on the outer peripheral wall of the outer casing (1) at the position corresponding to the sensing button (5).

9. The capacitive sensor according to claim 1, characterized in that: The sensing button (5) is located on the side of the tail cover (2) close to the main control board (4), and the side of the tail cover (2) away from the main control board (4) is provided with the touch area (21) corresponding to the sensing button (5).

Images