Liquid heater

Abstract

The utility model provides a liquid heater, which relates to a liquid heater and comprises a glass cup body and an arc-shaped peripheral side wall of the glass cup body, a detection assembly is arranged on the arc-shaped peripheral side wall of the glass cup body in the vertical direction and comprises a flexible PCB (printed circuit board) substrate, and a temperature sensor is arranged on one side of the PCB substrate. The temperature sensor is arranged on the PCB substrate, the PCB substrate adjacent to the temperature sensor is covered with a capacitor copper foil, the PCB substrate is further provided with a plurality of independent copper foil wires, the PCB substrate is attached to the arc-shaped peripheral side wall of the glass cup body, the temperature sensor, the capacitor copper foil and the copper foil wires deform along with the PCB substrate, and the temperature sensor, the capacitor copper foil and the copper foil wires are all located on the same side of the PCB substrate. The liquid heater is used for solving the technical problem that in the prior art, the flexible PCB substrate is bent when being attached to the cup body, so that the electrical properties of components with different orientations have deviations of different trends, and the detection result of a sensor is further influenced.

Description

Technical Field

[0001] This utility model relates to the technical field of liquid heaters, and more specifically, to a liquid heater. Background Technology

[0002] Liquid heaters are typically household appliances designed to make it easier for people to boil water, brew tea, or prepare other beverages. To ensure safe use and provide convenient functionality, liquid heaters need to sense and detect the state of the beverage. Therefore, the side walls of the liquid heater cup are equipped with multiple sensors to detect the beverage's state.

[0003] For example, existing technology CN202222200376.X installs a water level sensor on the side wall of the kettle body. A through hole is provided in the side wall of the kettle body, and the sensor passes through the through hole to detect the water level. A handle is also used to conceal the sensor's wiring, improving the aesthetics of the liquid heater.

[0004] For example, prior art CN202121643473.5 also discloses an electric kettle in which the temperature measuring component is located on the outer surface of the glass body and is usually disposed in the mounting space between the handle and the glass body. In this way, the temperature measuring component can be fixed by the pressure between the inside of the handle and the outer wall of the glass body, so that the temperature measuring component is in close contact with the glass body to achieve accurate temperature measurement.

[0005] In actual installation, installing each sensor independently would lead to a cumbersome process. A common solution is to integrate the sensors onto a PCB substrate and then mount the PCB with the integrated sensors onto the outer wall away from the cup body. For example, in the prior art CN200820169572.2, the capacitive sensing metal component and the temperature sensor are both integrated onto the same PCB substrate.

[0006] PCBs are further divided into rigid PCB substrates and flexible PCB substrates. Rigid PCB substrates generally refer to PCB substrates made of rigid materials. The most common material for rigid PCBs is glass fiber reinforced epoxy resin (FR-4). Therefore, rigid PCB substrates have lower costs. For liquid heaters with similarly low selling prices (generally 50 to 200 yuan), rigid PCB substrates are often the preferred choice.

[0007] However, rigid PCB substrates are generally plate-shaped, while liquid heaters typically use cylindrical glass bodies. Especially for liquid heaters like those used in health-preserving kettles, the glass body often has a tapered design, making it difficult for the rigid PCB substrate to completely fit the glass. This results in varying distances between the sensor and the glass body at different locations. This is particularly problematic for temperature sensors and capacitor copper foil; if the distance between the same sensor and the glass body varies at different locations, it will affect the sensor's detection accuracy.

[0008] To avoid the problem of rigid PCB substrates not being able to fully adhere to the glass body, some existing technologies use flexible PCB substrates. Flexible PCBs use flexible materials that can be bent and folded, allowing the PCB substrate to adhere to the glass body and ensuring that the spacing between the sensor and the glass body is consistent.

[0009] The inventors discovered during practical use that, during the bonding process between the flexible PCB substrate and the curved outer perimeter of the glass cup, the bending of the flexible PCB substrate can cause microscopic deformation of the circuits and components on the PCB substrate due to the stress generated by the bending, leading to changes in the electrical performance of the circuits and components. Specifically, the amount of bending on the side of the flexible PCB facing the glass cup differs from the amount of bending on the side away from the glass cup. The deformation of the circuits and components on both sides of the flexible PCB is opposite (one compressed, one stretched). Therefore, even in symmetrically designed circuits, the electrical performance changes on both sides will have opposite trends during actual bending and use. For example, if an increase in impedance occurs on one side, a decrease in impedance is likely to occur on the other side. This not only increases sensor error but also affects the error deviation tendency of sensor detection, making it difficult to uniformly adjust various electrical components and ultimately hindering the achievement of high-precision detection. Utility Model Content

[0010] The purpose of this invention is to provide a liquid heater to solve the technical problem in the prior art where the flexible PCB substrate bends when it is attached to the cup, causing the electrical properties of components with different orientations to deviate in different directions, which further affects the sensor detection results.

[0011] This application provides a liquid heater, including a glass cup body and an arc-shaped outer peripheral sidewall of the glass cup body. A detection component is arranged vertically on the arc-shaped outer peripheral sidewall of the glass cup body. The detection component includes a flexible PCB substrate. A temperature sensor is provided on one side of the PCB substrate. A capacitor copper foil is covered on the PCB substrate adjacent to the temperature sensor. The PCB substrate also has multiple copper foil wires, which are electrically connected to the corresponding temperature sensor and capacitor copper foil. The PCB substrate is attached to the arc-shaped outer peripheral sidewall of the glass cup body. The temperature sensor, capacitor copper foil, and copper foil wires deform with the PCB substrate. The temperature sensor, capacitor copper foil, and copper foil wires are all located on the same side of the PCB substrate.

[0012] Furthermore, the temperature sensor, the capacitor copper foil, and the copper foil wire are located on the side of the PCB substrate away from the glass pot body, and an adhesive layer is provided on the side of the PCB substrate close to the glass pot body, and the adhesive layer is bonded to the glass cup body.

[0013] Furthermore, the aforementioned copper foil is arranged around the aforementioned temperature sensor, and both the temperature sensor and the aforementioned copper foil are horizontally centered on the aforementioned PCB substrate; or,

[0014] The aforementioned copper foil capacitor is disposed around the aforementioned temperature sensor, and the aforementioned temperature sensor is laterally offset on the aforementioned PCB substrate.

[0015] Furthermore, the aforementioned detection component also includes a ground port and an isolation circuit connected to the ground port. The isolation circuit is located on the same side of the PCB substrate as the temperature sensor and the capacitor copper foil, and the isolation circuit is located between the temperature sensor and the capacitor copper foil.

[0016] Furthermore, the aforementioned isolation circuit is electrically connected to the aforementioned temperature sensor.

[0017] Furthermore, the aforementioned capacitor copper foil includes a water level copper foil and an anti-overflow copper foil. The water level copper foil is located on the lower side of the aforementioned glass cup body, and the anti-overflow copper foil is located on the upper side of the water level copper foil, extending towards the upper side of the glass cup body.

[0018] Furthermore, the temperature sensor is attached to the copper foil for water level measurement.

[0019] Furthermore, the aforementioned detection component also includes a detection chip, which is located on the upper side of the aforementioned water level copper foil. The aforementioned water level copper foil, anti-overflow copper foil, and temperature sensor are all electrically connected to the detection chip via copper foil wires.

[0020] Furthermore, the temperature sensor, the capacitor copper foil, and the copper foil wire are located on the side of the PCB substrate closer to the glass pot, and the back area of ​​the PCB substrate where the capacitor copper foil is located is covered with shielding copper foil.

[0021] Furthermore, it also includes a handle, which is disposed on the outer wall of the glass body, and a receiving chamber is formed between the handle and the glass body, and the detection component is located in the receiving chamber.

[0022] Compared with the prior art, the embodiments of this utility model have at least the following advantages or beneficial effects:

[0023] The temperature sensor, capacitor copper foil, and copper foil conductors are all located on the same side of the PCB substrate. This ensures that during the bonding process between the flexible PCB substrate and the curved outer peripheral wall, the temperature sensor, capacitor copper foil, and copper foil conductors experience the same deformation direction and amount. This leads to more consistent component deviations, reducing the complexity of circuit design, production debugging, and subsequent maintenance. Furthermore, when designing the detection components, allowances can be made based on the curvature of the glass cup, further reducing errors. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the temperature sensor structure adjacent to the capacitor copper foil of this application.

[0025] Figure 2 This is a schematic diagram of the temperature sensor and capacitor copper foil of this application, which are horizontally centered on the PCB substrate.

[0026] Figure 3 This is a schematic diagram of the temperature sensor of this application being laterally offset on a PCB substrate.

[0027] Figure 4 This is a schematic diagram of the structure of the isolation circuit of this application, which is independently led out from the ground port.

[0028] Figure 5 This is a schematic diagram of the isolation circuit connecting the temperature sensor and the ground port in this application.

[0029] Figure 6 This is a schematic diagram of the structure of the water level copper foil, anti-overflow copper foil, and detection chip on the PCB substrate of this application.

[0030] Figure 7 This is an exploded structural diagram of the testing components, glass body, and handle of this application.

[0031] Figure label:

[0032] 100-Detection component, 1-PCB substrate, 101-Copper foil wire, 102-Ground port, 103-Detection chip, 104-Isolation circuit, 2-Temperature sensor, 3-Capacitor copper foil, 301-Water level copper foil, 302-Anti-overflow copper foil, 4-Glass cup body, 401-Handle. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] A liquid heater typically includes a heating element, a glass body 4, and a detection element 100. For aesthetic purposes, the glass body 4 is generally a cylindrical structure or a tapered structure whose outer diameter varies with the height. Regardless of whether the glass body 4 is cylindrical or tapered, its outer peripheral walls are curved inward.

[0035] The detection component 100 of this invention includes a PCB substrate 1, which is made of a flexible material, typically an insulating polyimide film. The flexible PCB substrate 1 facilitates fitting the inwardly curved outer peripheral wall of the glass cup 4. Generally, the surface of the PCB substrate 1 is pre-coated with copper foil, and copper foil wires 101 can be formed by etching the pre-coated copper foil. Multiple copper foil wires 101 are used for connections between electronic components. These multiple copper foil wires 101 are independent of each other and connected to corresponding sensors. Pads may also be provided at the ends of the copper foil wires 101 to facilitate soldering of electronic components such as the temperature sensor 2 and the capacitive copper foil 3.

[0036] The aforementioned temperature sensor 2 generally includes a surface-mount NTC (thermistor) soldered to the PCB substrate 1. The resistance of the NTC decreases as the temperature increases. During use, the temperature change can be converted into a voltage signal through a voltage divider circuit or other means.

[0037] The aforementioned capacitor copper foil 3 can be formed by etching pre-coated copper foil. When the liquid level or foam height changes, the medium at the corresponding location of the glass liner changes, thereby altering the capacitance value detected by the capacitor copper foil 3, and thus calculating the height of the liquid or foam. The aforementioned detection component 100 is arranged vertically on the outer peripheral sidewall of the glass cup 4, thereby increasing the detection range of the capacitor copper foil 3 in the height direction, which is beneficial for the capacitor copper foil 3 to detect water level or foam over a wider range.

[0038] During the installation of the detection component 100, the outer peripheral walls of the glass cup 4 are all bent inward. After the center of the conventional rigid PCB is attached to the outer peripheral wall of the glass cup 4, the left and right ends of the rigid PCB cannot be completely attached to the outer peripheral wall of the glass cup 4, and the gap between the left and right ends of the rigid PCB and the glass cup 4 gradually increases, which is not conducive to the accurate detection of liquid level by the capacitor copper foil 3. In this utility model, the flexible PCB substrate 1 is bent inward along the outer peripheral wall of the glass cup 4 (sometimes the PCB substrate 1 is also bent inward along the height direction with the outer peripheral wall of the glass cup 4). The PCB substrate 1 can deform according to the curvature of the arc-shaped outer peripheral wall of the glass cup 4, so that the PCB substrate 1 is attached to the glass cup 4.

[0039] However, when the flexible PCB substrate 1 is attached to the outer peripheral wall of the glass cup 4, the PCB substrate 1 bends. The side of the PCB substrate 1 closest to the glass cup 4 has a smaller radius of curvature after bending, and compared to its original straight state, the copper foil conductor 101, temperature sensor 2, and capacitor copper foil 3 on that side of the glass cup 4 are compressed. The side of the PCB substrate 1 furthest from the glass cup 4 has a larger radius of curvature after bending, and the corresponding bending radius is longer, so it tends to be "stretched," and the copper foil conductor 101, temperature sensor 2, and capacitor copper foil 3 bear tensile stress.

[0040] Specifically, for the copper foil conductor 101, when it is located on the side of the PCB substrate 1 away from the glass cup 4, the copper foil conductor 101 is stretched, resulting in an increase in width and a decrease in thickness, making it thinner overall, reducing its cross-sectional area, and increasing its resistance. When the copper foil conductor 101 is located on the side of the PCB substrate 1 closer to the glass cup 4, the copper foil conductor 101 is compressed, resulting in a decrease in width and an increase in thickness, making it thicker overall, increasing its cross-sectional area, and decreasing its resistance.

[0041] For the capacitor copper foil 3, its capacitance value is directly proportional to its detection area. When the capacitor copper foil 3 is located on the side of the PCB substrate 1 away from the glass cup 4, it deforms slightly and is stretched, causing the upper limit of its capacitance value to tend to increase. When the copper foil conductor 101 is located on the side of the PCB substrate 1 closer to the glass cup 4, the capacitor copper foil 3 is compressed, causing the upper limit of its capacitance value to tend to decrease.

[0042] For temperature sensor 2, the common internal structure of an NTC mainly consists of a semiconductor ceramic and multilayer internal electrodes inserted into the semiconductor ceramic. Slight changes in the internal lattice structure of the semiconductor ceramic can cause corresponding deformation of the internal electrodes, thus affecting the distribution and migration rate of charge carriers. When temperature sensor 2 is located on the side of PCB substrate 1 away from the glass cup 4, it is stretched, tending to slightly increase resistance. When temperature sensor 2 is located on the side of PCB substrate 1 away from the glass cup 4, it is compressed, and the compression may increase the local concentration of charge carrier density, tending to slightly decrease resistance. Similarly, the flexible NTC will also undergo slight deformation with the PCB substrate 1, producing a similar tendency-based error change.

[0043] In summary, although the flexible PCB substrate 1 possesses a certain degree of flexibility and ductility, the stress distribution differences caused by bending the PCB substrate 1 still affect the physical characteristics of the copper foil conductor 101 and the sensor. The resistance of the copper foil conductor 101 may change slightly when stretched or compressed; the electrical performance of components such as the capacitor copper foil 3 and the temperature sensor 2 will also deviate due to stress changes. In particular, when components are distributed on both the inner and outer surfaces of the flexible PCB substrate 1, the asymmetrical stress distribution caused by bending leads to differences in the electrical characteristics and long-term reliability of the components on both sides, increasing the complexity of circuit design, production debugging, and subsequent maintenance.

[0044] Therefore, in this invention, the temperature sensor 2, the capacitor copper foil 3, and the copper foil wire 101 are all located on the same side of the PCB substrate 1. This ensures that during the bonding process between the flexible PCB substrate 1 and the arc-shaped outer peripheral sidewall, the temperature sensor 2, the capacitor copper foil 3, and the copper foil wire 101 experience the same deformation direction and amount, resulting in a more consistent trend in component deviations. This reduces the complexity of circuit design, production debugging, and subsequent maintenance. Furthermore, when designing the detection component 100, allowance can be provided based on the curvature of the glass cup 4 to further reduce errors.

[0045] Furthermore, in practical use, it was found that the flexible PCB substrate 1 is relatively soft and fragile, making it difficult to position using rigid components. Therefore, the temperature sensor 2, the capacitor copper foil 3, and the copper foil wire 101 can be located on the side of the PCB substrate 1 away from the glass body. An adhesive layer is provided on the side of the PCB substrate 1 closest to the glass body, and the adhesive layer is bonded to the glass body 4. The adhesive layer can be common double-sided tape, which allows the PCB substrate 1 to fit tightly against the glass body, reducing bending and movement of the PCB substrate 1 during installation.

[0046] More importantly, when the PCB substrate 1 is bonded to the glass vessel body via the adhesive layer, the PCB substrate 1 and the curved outer peripheral wall of the glass vessel body form a relatively stable connection structure. In this way, the side closer to the vessel body is supported by the adhesive layer, and even if the components on the far side experience slight bending, they will operate in a relatively stable environment. This reduces deviations in electrical parameters (such as capacitance and resistance) caused by bending stress, ensuring more consistent and controllable component performance.

[0047] In addition to using an adhesive layer, tape can also be used to fix the PCB substrate 1 to the glass cup body from the side away from the glass cup body. Alternatively, brackets or other means can be used to fix the detection component 100 and the glass cup body 4. In this case, there may be a gap between the detection component 100 and the glass cup body 4, but the PCB substrate 1 still deforms with the arc-shaped outer peripheral sidewall of the glass cup body 4. This is also considered by those skilled in the art to be a case where "the PCB substrate 1 is attached to the arc-shaped outer peripheral sidewall of the glass cup body 4".

[0048] The shape of the capacitor copper foil 3 is generally a regular rectangle following the shape of the PCB substrate 1. To ensure the detection area of ​​the capacitor copper foil 3, and to accommodate the connection of the temperature sensor 2 to the copper foil wire 101, the temperature sensor 2 can be independently located in the adjacent area of ​​the capacitor copper foil 3. Figure 1 As shown, compared to the embodiments below, the temperature sensor 2 described above in this embodiment does not visually "embed" the capacitor copper foil 3.

[0049] To reduce the area of ​​the detection component 100, the aforementioned capacitive copper foil 3 can be arranged around the temperature sensor 2. Compared to the previous embodiment, in this embodiment, the temperature sensor 2 is visually "embedded" in the capacitive copper foil 3. Specifically, the capacitive copper foil 3 forms an area on the PCB substrate 1 that is not covered by copper foil, either enclosed or partially enclosed. The temperature sensor 2 is located in this area without copper foil coverage. The temperature sensor 2 and the surrounding capacitive copper foil 3 are independent of each other, which helps to reduce interference between the temperature sensor 2 and the capacitive copper foil 3, and improves the accuracy and stability of temperature measurement.

[0050] In practical use, it can be like Figure 2 As shown, both the temperature sensor 2 and the aforementioned copper capacitor foil 3 are horizontally centered on the PCB substrate 1. This allows for a more symmetrical and uniform positioning of the copper capacitor foil 3 and the temperature sensor 2 on the PCB substrate 1, which is beneficial for the temperature sensor 2 to detect heat from its surroundings. Alternatively, as shown... Figure 3 As shown, the temperature sensor 2 can also be laterally offset on the PCB substrate 1, and the temperature sensor 2 is closer to the edge of the PCB substrate 1, so that the copper foil wire 101 connected to the temperature sensor 2 can be led out through a shorter and more direct path, thereby simplifying the wiring.

[0051] On the other hand, the aforementioned copper foil 3 is arranged around the temperature sensor 2, meaning that the temperature sensor 2 and the copper foil 3 are on the same horizontal plane. When the copper foil 3 is below the lowest water level line of the glass body 4, it can be used to detect whether the liquid level has reached the lowest water level line, thereby preventing the liquid heater from dry-burning. To further improve the accuracy of dry-burning detection, when the liquid level is below the lowest water level line, the temperature sensor 2 and the copper foil 3 are on the same horizontal plane, and the temperature sensor 2 detects whether the temperature is abnormal, thus assisting the copper foil 3 in detecting dry-burning.

[0052] When the capacitive copper foil 3 is located on the upper side of the glass body 4 (e.g., near the maximum water level), it can be used to detect the liquid level and foam, thus preventing the beverage and foam from overflowing. The temperature sensor 2 is located on the same horizontal plane as the capacitive copper foil 3. When the liquid level and foam are about to overflow, the heat carried by the liquid and foam is transferred to the temperature sensor 2, causing abnormal detection data. Therefore, the temperature sensor 2 assists the capacitive copper foil 3 in detecting overflow.

[0053] For liquid heaters, the outer diameter of the widest part of the glass vessel is generally around 200mm. Since the detection component 100 is typically arranged vertically, and for aesthetic reasons and ease of installation, the width of the PCB substrate 1 is set to around 20mm. During use, it was found that the relatively small width of the PCB substrate 1 can cause interference when the temperature sensor 2 and the capacitor copper foil 3 are too close. To reduce interference, existing technologies often maintain a safe distance between the capacitor copper foil 3 and the temperature sensor 2. For example, when the PCB substrate 1 is 20mm wide, the electrode copper foil is horizontally distributed on the PCB substrate 1, and a safe distance of at least 0.6mm is maintained between the electrode copper foil and its copper foil conductor 101 and the temperature sensor 2.

[0054] As one embodiment of this application, such as Figure 4 As shown, the detection component 100 may further include a ground port 102 and an isolation circuit 104 connected to the ground port 102. The isolation circuit 104 is located on the same side of the PCB substrate 1 as the temperature sensor 2 and the capacitor copper foil 3, and is located between the temperature sensor 2 and the capacitor copper foil 3. The ground port 102 provides a safe electrical reference point or grounding path for the isolation circuit 104, which electrically isolates the temperature sensor 2 from the capacitor copper foil 3, thereby improving the anti-interference capability of the capacitor copper foil 3 and eliminating the need for an excessively wide safety distance.

[0055] To further improve the utilization rate of PCB substrate 1, such as Figure 5 As shown, the isolation circuit 104 can be electrically connected to the temperature sensor 2. Specifically, the temperature sensor 2 typically uses an NTC (thermistor) and a fixed resistor to form a voltage divider circuit, calculating the temperature by measuring voltage changes. A common approach is to use an NTC as a pull-down resistor, in which case the NTC needs to be connected to the ground port 102. By connecting the temperature sensor 2 and the ground port 102 through the isolation circuit 104, not only is a separate copper foil wire 101 connected to the ground port 102 unnecessary, but the isolation circuit 104 can also simultaneously achieve electrical isolation between the temperature sensor 2 and the capacitive copper foil 3.

[0056] In practical applications, there may be a need to simultaneously detect water level and foam. Therefore, the aforementioned capacitor copper foil 3 may include a water level copper foil 301 and an anti-overflow copper foil 302. When the water level copper foil 301 is used to detect water level, it can be located on the lower side of the glass body 4 to ensure normal water level detection even at low water levels. The anti-overflow copper foil 302 is used to detect when beverages or foam overflow from the rim of the glass. Therefore, the anti-overflow copper foil 302 can be located above the water level copper foil 301 and extends upwards towards the glass body 4, thereby expanding the detection range.

[0057] Furthermore, the temperature sensor 2 is attached to the water level copper foil 301. In addition to assisting in dry burning, the temperature sensor 2 can also detect the temperature of the beverage when the water level is low.

[0058] To further improve the detection accuracy of the capacitor electrode, the copper foil 301 for water level includes a first sub-electrode and a second sub-electrode, which are arranged side-by-side on the PCB substrate 1. In practical applications, the arrangement of the first and second sub-electrodes can be designed according to specific requirements.

[0059] When focusing on measuring changes in water level height, the second sub-electrode of the first sub-electrode can be distributed along the same vertical line. The longitudinally parallel arrangement of sub-electrodes provides finer resolution in the vertical direction, thus enabling more accurate water level height measurement.

[0060] When the focus is on improving detection accuracy, the second sub-electrodes of the first sub-electrode can be distributed along the same horizontal line, achieving a horizontally parallel arrangement. Horizontally parallel sub-electrodes provide a wider detection range, thereby improving water level detection accuracy on a horizontal plane. In a horizontally parallel arrangement, each individual sub-electrode can also be vertically positioned. Vertical positioning can cover a larger range of liquid level heights, providing stable detection results even at low or high liquid levels, and avoiding loss of detection function due to extreme changes in liquid level.

[0061] In practical applications, the detection assembly 100 formed on the PCB substrate 1 by the temperature sensor 2 and the capacitor electrode can be a detection board integrating the detection chip 103 and / or the anti-overflow electrode, or it can be used as a separate detection accessory.

[0062] When the detection component 100 further includes a detection chip 103, the water level copper foil 301, the anti-overflow copper foil 302, and the temperature sensor 2 are all electrically connected to the detection chip 103 via copper foil wires 101. To detect whether the liquid heater is dry-burning, the water level copper foil 301 needs to be installed as close as possible to the lower side of the glass body 4. Therefore, the detection chip 103 is located above the water level copper foil 301 to prevent it from occupying the lower space of the glass body 4.

[0063] like Figure 6 As shown, if the installation space for the liquid heater is small, the size of the PCB substrate 1 needs to be reduced as much as possible. To further reduce the size of the PCB substrate 1, the temperature sensor 2 can be placed on the left or right side of the detection chip 103, so that the capacitor can also extend to the rear area of ​​the PCB substrate 1 where the detection chip 103 is located.

[0064] The detection component 100 also includes an anti-overflow electrode. The anti-overflow electrode detects changes in the liquid and foam inside the glass cup 4 by detecting changes in the capacitance value. To improve detection accuracy, the anti-overflow electrode needs to be closer to the glass cup 4; therefore, the anti-overflow electrode is located on the side of the PCB substrate 1 facing the glass cup 4. To prevent the anti-overflow electrode from occupying the lower space of the glass cup 4, the temperature sensor 2 and the capacitor electrode are located below the anti-overflow electrode.

[0065] When the detection component 100 is a standalone detection accessory, the PCB substrate 1 only contains the temperature sensor 2 and the capacitor electrode. In this case, the detection component 100 can be electrically connected to a coupler or to the circuit board inside the bottom cover via a long wire or hardware component.

[0066] The temperature sensor 2, the capacitor copper foil 3, and the copper foil conductor 101 are located on the side of the PCB substrate 1 closest to the glass cup 4, allowing the capacitor copper foil 3 and the temperature sensor 2 to directly face or be close to the glass cup 4, thus improving the detection accuracy of the temperature sensor 2 and the capacitor copper foil 3. To reduce interference from the back area of ​​the PCB substrate 1 to the capacitor copper foil 3, a shielding copper foil is provided on the back area of ​​the PCB substrate 1 where the capacitor copper foil 3 is located. This shielding copper foil can be grounded and can protect the capacitor copper foil 3 and the copper foil conductor 101 from external interference. The shielding copper foil can be formed as a mesh of copper foil conductors 101 or as a serpentine copper foil conductor 101.

[0067] like Figure 7 As shown, the liquid heater also includes a handle 401, which is located on the outer wall of the glass body 4 for easy handling by the user. To protect and house the detection component 100, a receiving chamber is formed between the handle 401 and the glass body 4, and the detection component 100 is located within the receiving chamber.

[0068] Furthermore, it should be noted that the liquid heater of this utility model is not limited to the food processing machine with an integrated motor and cup body disclosed in the embodiments of this utility model. It can also be a soy milk maker with the motor mounted on top, a blender with a separate cup body and base, and a hand-washable food processing machine that can automatically discharge and clean itself. Moreover, the liquid heater of this utility model can also be applied to heating appliances that can perform boiling operations, rice paste making, etc., such as health pots and health cookers.

[0069] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A liquid heater, comprising a glass cup body, an arc-shaped outer peripheral sidewall of the glass cup body, and a detection component arranged vertically on the arc-shaped outer peripheral sidewall of the glass cup body, characterized in that: The detection component includes a flexible PCB substrate. A temperature sensor is disposed on one side of the PCB substrate. The adjacent PCB substrate to the temperature sensor is covered with capacitive copper foil. The PCB substrate also has multiple copper foil wires, which are electrically connected to the corresponding temperature sensor and capacitive copper foil, respectively. The PCB substrate is attached to the arc-shaped outer peripheral wall of the glass cup. The temperature sensor, the capacitor copper foil, and the copper foil wire deform with the PCB substrate. The temperature sensor, the capacitor copper foil, and the copper foil wire are all located on the same side of the PCB substrate.

2. A liquid heater according to claim 1, characterized in that: The temperature sensor, the capacitor copper foil, and the copper foil wire are located on the side of the PCB substrate away from the glass body. An adhesive layer is provided on the side of the PCB substrate close to the glass body, and the adhesive layer is bonded to the glass body.

3. A liquid heater according to claim 1, characterized in that: The capacitive copper foil is arranged around the temperature sensor, and both the temperature sensor and the capacitive copper foil are horizontally centered on the PCB substrate; or... The capacitor copper foil is arranged around the temperature sensor, and the temperature sensor is laterally offset on the PCB substrate.

4. A liquid heater according to claim 1, characterized in that: The detection component also includes a ground port and an isolation circuit connected to the ground port. The isolation circuit is located on the same side of the PCB substrate as the temperature sensor and the capacitor copper foil, and the isolation circuit is located between the temperature sensor and the capacitor copper foil.

5. A liquid heater according to claim 4, characterized in that: The isolation circuit is electrically connected to the temperature sensor.

6. A liquid heater according to claim 1, characterized in that: The capacitor copper foil includes a water level copper foil and an anti-overflow copper foil. The water level copper foil is located on the lower side of the glass body, and the anti-overflow copper foil is located on the upper side of the water level copper foil, extending towards the upper side of the glass body.

7. A liquid heater according to claim 6, characterized in that: The temperature sensor is attached to the copper foil for water level measurement.

8. A liquid heater according to claim 6, characterized in that: The detection component also includes a detection chip located on the upper side of the water level copper foil. The water level copper foil, the overflow prevention copper foil, and the temperature sensor are all electrically connected to the detection chip via copper foil wires.

9. A liquid heater according to claim 1, characterized in that: The temperature sensor, the capacitor copper foil, and the copper foil wire are located on the side of the PCB substrate close to the glass pot body, and the back area of ​​the PCB substrate where the capacitor copper foil is located is covered with shielding copper foil.

10. A liquid heater according to claim 1, characterized in that: It also includes a handle, which is disposed on the outer wall of the glass body, and a receiving chamber is formed between the handle and the glass body, and the detection component is located in the receiving chamber.

Images