Control method of liquid heater

Abstract

The invention provides a control method of a liquid heater, and relates to a liquid heater, the liquid heater comprises a heating container and a plurality of capacitance pole pieces arranged on the outer wall of the heating container, the capacitance pole pieces are arranged along the height direction of the heating container, and the capacitance pole pieces are used for detecting overflow signals. A first pole piece and a second pole piece which are higher than the initial liquid level of the beverage are arranged in the capacitance pole piece, the first pole piece is higher than the second pole piece, when the first pole piece detects an overflow signal, the heating power of the heating container is reduced, and when the second pole piece does not detect the overflow signal any more, the heating power of the heating container is recovered. The control method of the liquid heater is used for solving the technical problems in the prior art that in order to prevent foam from overflowing, the change of the foam is not continuously detected after the foam is detected, so that the liquid heater frequently stops heating, and drinks cannot be stably turned over for a long time.

Description

Technical Field

[0001] This invention relates to the technical field of liquid heaters, and more specifically, to a control method for a liquid heater. Background Technology

[0002] During the use of liquid heaters, especially when making beverages that easily produce foam, such as white fungus, rice porridge, and soy milk, the ingredients in the beverage are gradually released as the heating time increases. This leads to an increase in the beverage's concentration and viscosity, forming a large amount of foam that is difficult to break, resulting in foam accumulation and overflow. Overflowing foam may adhere to the heater surface and surrounding area, making it difficult to clean. In addition, foam overflow may cause electrical short circuits, increasing the risk of electric shock or fire.

[0003] To avoid the problem of foam overflow, the initial technical solution used one or more temperature sensors to detect temperature changes in the beverage and thus predict the possibility of overflow.

[0004] For example, prior art CN201210006121.8 discloses a soymilk maker and its overflow signal detection method, which includes two temperature sensors. The first temperature sensor (detecting temperature T1) is located below the initial liquid surface, and the second temperature sensor (detecting temperature T2) is located above the initial liquid surface, detecting the temperature of steam or soymilk foam. When the soymilk has not overflowed, there is steam on the liquid surface, and the temperature difference is large (T1-T2> preset value T, such as 10℃). When soymilk foam overflows and contacts the second sensor, T2 approaches the soymilk temperature, the temperature difference decreases (T1-T2≤T), triggering an overflow signal, immediately stopping heating, and preventing soymilk from overflowing.

[0005] This existing technology uses temperature changes above the liquid surface as the basis for foam height detection. While it solves the problems of misjudgment and space occupation associated with electrode detection, its "temperature changes above the liquid surface" method cannot accurately detect whether the foam has risen to the location of the temperature sensor in some cases. Specifically: 1. In low-temperature environments, the temperature value detected by the second temperature sensor is easily affected by the ambient temperature, causing the measured temperature difference to be close to or less than the preset value, which may lead to unexpected heating stoppage; 2. In some extreme cases, since foam rise is an instantaneous process, when the foam quickly covers the second sensor, the sensor needs time to sense the temperature change, and the foam itself contains a large amount of steam, which may make it difficult for the second temperature sensor to detect the temperature change in time, and overflow may still occur.

[0006] To directly detect the liquid level or foam height, liquid heaters prevent overflow through contact electrode detection or float detection. For example, prior art CN90100704.8 discloses a fully automatic household soy milk maker, where the liquid heater has a probe in the lid. The probe detects the resistance formed by foam adhering to the wall of the heating container or between the probes, thereby detecting whether foam has overflowed. Upon detection of overflow, the heating power is immediately cut off to prevent foam accumulation due to continuous heating. However, contact electrodes need to extend into the heating container and come into contact with the beverage, which is not conducive to cleaning the heating container.

[0007] Given the limitations of contact electrodes, liquid heaters also employ non-contact capacitive electrodes for foam detection. These electrodes are mounted on the outer wall of the heating container. Different dielectric constants exist between electrodes corresponding to different foam heights or liquid levels, resulting in different detected values. The presence and level of foam are determined based on these numerical changes. This detection method eliminates the need for direct contact with the liquid, making it safe and reliable.

[0008] For example, prior art CN97225228.2 discloses a multi-functional anti-overflow control device for an electrothermal film glass cup (pot), which has three transparent conductive films attached to the outer surface of the glass cup: one conductive film is located at 4 / 5 of the cup height (to detect the boiling liquid level); the remaining two conductive films are set near the bottom of the cup (about 1 cm from the bottom, to detect the lowest liquid level). The liquid and the conductive films form a capacitor through the glass medium. Changes in liquid level change the capacitance value, affecting the load characteristics of the oscillation circuit, and thus converting it into a DC level signal.

[0009] In summary, from a control logic perspective, whether it's electrode detection or float detection, there is essentially only one detection point. When the detection point detects an overflow signal, the heating power is immediately cut off, thus quickly responding to the foam. When the foam level drops below the detection point, heating is resumed, causing the liquid heater to frequently operate in an intermittent heating state. This results in insufficient heating time for the ingredients in the beverage, affecting the release of nutrients from the ingredients.

[0010] To further improve the cooking time of ingredients in beverages, prior art CN201710035787.9 discloses an electric cooker and its anti-overflow heating control method and device. This prior art has a foam detection component on the upper cover. The duration of foam detection is used to dynamically calculate the heating stop time T1. If the foam duration is short, it indicates that the foam is not serious, and a shorter stop time may be set; if the foam duration is long, the heating stop time will be increased accordingly to ensure that the foam is fully processed.

[0011] However, this existing technology relies on the accumulation of time to judge the foam situation, which is not accurate enough. Its foam characteristics are greatly affected by the viscosity of the beverage, and the liquid heater may still frequently stop heating. Summary of the Invention

[0012] The purpose of this invention is to provide a control method for a liquid heater, which solves the technical problem in the prior art that, in order to prevent foam overflow, the liquid heater does not continue to detect changes in foam after foam is detected, causing the liquid heater to frequently stop heating and the beverage to fail to achieve a stable bubbling effect over a long period of time.

[0013] This application provides a control method for a liquid heater. The liquid heater includes a heating container and a plurality of capacitor plates disposed on the outer wall of the heating container. The plurality of capacitor plates are disposed along the height direction of the heating container. The capacitor plates are used to detect overflow signals. The capacitor plates are respectively configured with a first plate and a second plate that are higher than the initial liquid level of the beverage. The first plate is higher than the second plate. When the first plate detects an overflow signal, the heating container reduces the heating power. When the second plate no longer detects an overflow signal, the heating container restores the heating power.

[0014] Furthermore, between the lower side of the first electrode and the liquid level, multiple capacitor electrodes of different heights constitute a first detection zone; the control method selects and sets the second electrode from the first detection zone according to the instructions of the liquid heater.

[0015] Furthermore, between the upper side of the second electrode and the upper edge of the liquid heater, multiple capacitor electrodes of different heights constitute a second detection area; the control method selects and sets the first electrode from the second detection area according to the instructions of the liquid heater.

[0016] Furthermore, when the second electrode no longer detects an overflow signal, and the first electrode no longer detects an overflow signal, the heating container resumes heating.

[0017] Furthermore, when the second electrode detects an overflow signal, and the first electrode detects an overflow signal, the heating container stops heating.

[0018] Furthermore, in the initial state, the first electrode is the capacitor electrode at the highest position of the heating container.

[0019] Furthermore, when the first electrode detects an overflow signal, the heating container stops heating.

[0020] This application provides a control method for a liquid heater, which dynamically adjusts the heating power by calculating the time interval t between the detection of an overflow signal.

[0021] Furthermore, the ratio of t to the target time T is used as the adjustment coefficient α. The current heating power is multiplied by α to obtain the dynamic adjustment power for the next stage, and the new power is applied after the anti-overflow release condition is met.

[0022] Furthermore, the target time T increases with the number of times the overflow signal is detected; or, the target time T is a fixed value.

[0023] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0024] This invention, by setting an overflow detection point (first electrode) and a fall detection point (second electrode), can directly detect whether the foam has reached a set height, achieving closed-loop control. In particular, it can directly detect whether the foam or liquid level is below the second electrode, accurately controlling the timing of resuming heating. Furthermore, by adjusting the height difference between the first and second electrodes, the amplitude of foam fluctuations can be controlled, thereby adjusting the frequency of resuming heating and reducing heating power in the heating container, avoiding frequent reductions in heating power. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the overflow detection process of some embodiments of this application.

[0026] Figure 2 This is a flowchart illustrating the overflow detection process of some embodiments of this application.

[0027] Figure 3 This is a flowchart illustrating the overflow detection process of some embodiments of this application.

[0028] Figure 4 This is a graph showing the change in heating power Pn during the cooking stage in some embodiments of this application.

[0029] Figure 5 This is a graph showing the change in heating power Pn during the cooking stage in some embodiments of this application.

[0030] Figure 6 This is a schematic diagram of the liquid heater in Embodiment Eleven of this application.

[0031] Figure 7 This is a schematic diagram of the structure of the liquid heater electrode rod and handle in Embodiment 11 of this application.

[0032] Figure 8 This is a schematic diagram of the structure of the liquid heater electrode plate, threaded column, and rubber pad in Embodiment 11 of this application.

[0033] Figure 9 This is a schematic diagram of the structure of the liquid heater pad in Embodiment 11 of this application.

[0034] Figure label:

[0035] 1-Electrode rod, 2-Handle, 101-Electrode sheet, 102-Threaded post, 103-Rubber pad. Detailed Implementation

[0036] The following will refer to the appendices in the embodiments of the present invention. Figure 1-9 As shown, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] Existing technologies have been continuously improved to avoid the problem of foam overflow. From initially predicting foam overflow by temperature, to using contact electrodes to detect overflow signals, to non-contact electrodes to detect overflow signals, and finally to dynamically calculating the time when heating needs to be stopped based on the "length of foam persistence," existing technologies have minimized the need for frequent heating stoppages of liquid heaters while ensuring that foam does not overflow.

[0038] However, existing technologies often set the highest electrode as the detection point for stopping and resuming heating, so that no matter how the control logic is adjusted, it is an "open-loop" control method based on time or temperature prediction, and the foam state is no longer detected in real time after heating stops.

[0039] Therefore, to address the technical problem of existing technologies that, in order to prevent foam overflow, fail to continue monitoring foam changes after foam is detected, causing the liquid heater to frequently stop heating and preventing the beverage from achieving a stable, long-term bubbling, this invention arranges multiple capacitor plates along the height direction on the outer wall of the heating container. This allows for direct detection of the real-time foam height (especially the foam height after heating has stopped), thereby adjusting the heating state of the liquid heater and achieving dynamic control over the upper and lower limits of foam fluctuations.

[0040] Specifically, a liquid heater includes a heating container, which may include common heating components (such as heating plates or thick film heating components) and a container (which may be made of glass or metal).

[0041] The liquid heater also includes capacitor plates disposed on the outer wall of the heating container. The capacitor plates, together with the heating container (typically the bottom wall) or another electrode, form a capacitor; when the height of foam or liquid changes within the capacitor, the foam or liquid replaces the air, causing a change in capacitance. When the detected capacitance exceeds a threshold, the capacitor plates are considered to have detected an overflow signal; when the capacitance is below the threshold, the capacitor plates do not detect an overflow signal.

[0042] The aforementioned capacitor plates are multiple, arranged along the height direction of the heating container. When detecting foam or liquid level, the foam or liquid level will cause the capacitor plates to detect an overflow signal. Therefore, the foam or liquid level is generally located between two adjacent capacitor plates that "detect an overflow signal" and those that "do not detect an overflow signal".

[0043] The capacitor electrodes described above are respectively configured with a first electrode and a second electrode that are higher than the initial liquid level of the beverage. This ensures that during normal heating (when no overflow occurs), the first and second electrodes will not be covered by liquid.

[0044] The first electrode is higher than the second electrode. When the first electrode detects an overflow signal, the heating container reduces its heating power; when the second electrode no longer detects an overflow signal, the heating container restores its heating power. In use, due to the height of the first electrode, a "buffer distance" is generally left between it and the spout of the heating container to ensure that the heating container reduces its heating power before overflowing.

[0045] Compared to single-point detection solutions that only check for foam overflow, these methods cannot determine if there is still a risk of overflow, making it difficult to balance heating time and overflow prevention. Even if existing technologies can determine the duration of heating stoppage based on the "duration of foam presence," it is still difficult to accommodate all scenarios. If the foam in high-sugar / high-protein drinks is viscous and dissipates slowly, the fixed detection time may still be too short, leading to secondary overflow. Therefore, in practical use, multiple sets of empirical parameters such as detection times need to be preset for different recipes, resulting in high adaptation costs. This invention eliminates the need for long, fixed cooling waits; instead, it resumes heating in real time upon detecting that the foam has subsided, thus increasing the time the beverage is heated and agitated.

[0046] On the other hand, starting with early contact electrodes, those skilled in the art believed that as long as heating was stopped after detecting foam at the highest detection point, foam overflow could be prevented; furthermore, contact electrodes measured the liquid level through circuit conduction, making it difficult to achieve closed-loop control. Therefore, based on the inertia of technological development, those skilled in the art tended to "add redundant sensors at the top" or "improve the timing formula" rather than arranging multiple electrodes on the sidewalls and designing dual-detection-point closed-loop control.

[0047] In summary, this invention, by setting an overflow detection point (first electrode) and a fall detection point (second electrode), can directly detect whether the foam has reached a set height, achieving closed-loop control. In particular, it can directly detect whether the foam or liquid level is below the second electrode, accurately controlling the timing of resuming heating. Furthermore, by adjusting the height difference between the first and second electrodes, the amplitude of foam fluctuations can be controlled, thereby adjusting the frequency of resuming heating and reducing heating power in the heating container, avoiding frequent reductions in heating power.

[0048] Those skilled in the art will understand that the aforementioned "initial liquid level" refers to the initial liquid level height when the user pours in the liquid (such as water, coffee, etc.) before heating. For example, when a user pours a cup of water into a heating container, the water level at that moment is the initial liquid level.

[0049] During implementation, the first and second electrodes can be positioned above the highest water level line to ensure they are above the initial liquid level of the beverage. Alternatively, the initial liquid level of the beverage can be detected first, and then the heights of the first and second electrodes can be dynamically adjusted.

[0050] In some embodiments, the liquid heater includes a control chip, which is used to detect and determine whether the original signal exceeds a threshold (i.e., whether an overflow signal is detected). The specific overflow detection process of the liquid heater is as follows:

[0051] 1. The control chip detects the original signal generated by the capacitor plate at the top of the liquid heater and the original signal generated by the capacitor plate below the top (the threshold for the original signal generated by the control chip for capacitor plates at different heights may be different).

[0052] 2. When the control chip detects that the original signal generated by the top capacitor exceeds the threshold, the heating container reduces the heating power to prevent foam from overflowing, until the original signal of the top capacitor is lower than the threshold.

[0053] 3. When the original signal of the capacitor electrode on the lower side of the top of the control chip is lower than the threshold, the heating container increases the heating power.

[0054] In some embodiments of this example, the control chip detects that the original signal of the capacitor electrode on the lower side of the top is lower than a threshold, until the original signal of the capacitor electrode on the lower side of the top exceeds the threshold.

[0055] In some implementations, if the original signal of the capacitor electrode on the lower side of the top is detected to be below a threshold, the original signal of the capacitor electrode on the top can be detected again to see if it is below the threshold. When the original signal of the capacitor electrode on the top is below the threshold, the heating container increases the heating power to prevent the capacitor electrode on the lower side of the top from being affected by noise interference.

[0056] In Example 1, the first and second electrodes can be positioned above the highest water level line.

[0057] The heating container can be equipped with only three capacitor electrodes: a first electrode, a second electrode, and a bottom electrode below the first and second electrodes. Those skilled in the art will readily understand that the bottom electrode can form a capacitor with both the first and second electrodes. Both the first and second electrodes are located on the upper side of the heating container. The bottom electrode can be located on the side wall below the lowest water level or on the bottom wall of the heating container. This design uses only three capacitor electrodes to achieve the control method of this invention, while also simplifying PCB routing, MCU sampling channels, and mounting processes, making it suitable for price-sensitive liquid heaters.

[0058] In some embodiments of this example, (taking a health-preserving kettle as an example), the highest water level line for the stewing function is generally located 50mm to 85mm below the spout (1.3L capacity). Therefore, the first and second electrodes need to be positioned between the spout and the highest water level line. For a health-preserving kettle where the difference between the spout and the highest water level line is 70mm, the second electrode can be positioned approximately 10mm above the highest water level line, and the first electrode can be positioned approximately 50mm above the highest water level line. This results in a height difference of approximately 20mm between the first electrode and the spout, providing sufficient safety distance. Even with this height difference of approximately 20mm, sufficient safety distance is still maintained.

[0059] For example, for a health pot where the spout is 70mm above the highest water level line, or for a health pot where the spout is 60mm above the highest water level line, the second electrode can be set about 10mm above the highest water level line, and the first electrode can be set about 40mm above the highest water level line.

[0060] The following are the control methods when making white fungus drinks:

[0061] 1. Gradually heat the beverage from room temperature to boiling;

[0062] 2. Keep the beverage boiling. The polysaccharides in the white fungus will gradually be released, the viscosity of the beverage will increase, and foam will begin to accumulate and gradually rise.

[0063] 3. When the foam rises to the point where the first electrode plate is immediately shut off, the heating power can be reduced or heating can be stopped. At this time, the height difference between the first electrode plate and the spout is about 20mm. Even if the foam continues to rise briefly due to thermal inertia, the foam will hardly overflow.

[0064] 4. When the heating power is reduced or heating is stopped, the foam will drop below the second electrode plate. Then, heating will be resumed to complete the remaining process.

[0065] In actual use, the height difference between the first electrode and the second electrode, the height difference between the first electrode and the spout or mouth of the kettle, and the height difference between the second electrode and the highest water level line can be set according to the actual situation.

[0066] The main influencing factor is the inner diameter of the heating container. When the inner diameter is larger, the lateral diffusion space of the foam is larger and the foam rises more slowly, resulting in a relatively smaller height difference. Conversely, when the inner diameter is smaller, the foam rises more rapidly, allowing for a relatively larger height difference. For example, when the inner diameter of the heating container is 120mm, the height difference between the first electrode and the spout can be set to 20mm–30mm; when the inner diameter of the heating container is 80mm, the height difference between the first electrode and the spout can be set to 30mm–40mm.

[0067] On the other hand, the heating power during the simmering stage needs to be coordinated with the various height differences. When the heating power is high, the liquid level fluctuations are also relatively large, so the height difference between the second electrode and the highest water level line can be appropriately increased to prevent the second electrode from continuously detecting an overflow signal due to liquid level fluctuations. When the heating power is high, the foam rises relatively quickly, so the height difference between the first electrode and the spout can also be appropriately increased. For example, when the diameter of the inner wall of the heating container is 80mm and the simmering power is 120W, the height difference between the first electrode and the spout is set at 25mm to 35mm, and the height difference between the second electrode and the highest water level line is about 10mm. When the inner wall diameter remains unchanged and the simmering power is 180W, the height difference between the first electrode and the spout is set at 30mm to 40mm, and the height difference between the second electrode and the highest water level line is about 15mm.

[0068] In Example 2, multiple capacitor plates (more than three) can be arranged along the height of the heating container. The initial liquid level of the beverage is detected first, and then the height of the first and second plates is dynamically set.

[0069] By detecting the initial liquid level (the position where the lowest liquid level electrode is submerged), the system automatically sets the first electrode at a safe distance (e.g., 30mm) above the initial liquid level, and the second electrode at 10mm above the initial liquid level. The system can adjust the height of the first and second electrodes regardless of whether the user injects 0.3L or 1L of liquid.

[0070] In some embodiments of this example, multiple capacitor electrodes can be arranged between the lowest water level line of the heating container and the spout (or mouth of the kettle). At least two electrodes must be located above the highest water level line to ensure that the first and second electrodes can be installed even at the highest water level.

[0071] For example, when the liquid heater is a soymilk maker, the control method for making soymilk is as follows:

[0072] 1. Detect the initial liquid level of the beverage, set the second electrode to be 10mm above the initial liquid level, and set the first electrode to be 35mm above the initial liquid level.

[0073] 2. Gradually heat the beverage from room temperature to boiling;

[0074] 3. When beans are crushed and continuously heated, the viscosity of the beverage increases, and foam begins to accumulate and gradually rises;

[0075] 4. When the foam rises to the point where the first electrode plate must be stopped immediately, the heating power can be reduced or heating can be stopped.

[0076] 5. When the heating power is reduced or heating is stopped, the foam will drop below the second electrode plate. Then, heating will be resumed to complete the remaining process.

[0077] In actual use, the overflow signal of the capacitor can be ignored when the soymilk maker is grinding and stirring, so as to prevent the interference of liquid level fluctuations on the capacitor during stirring and grinding.

[0078] In some implementations, the filtering time gradually shortens as the height increases, and the heating is stopped in a timely manner in response to the anti-overflow signal. This prevents the foam from reaching the height of the top capacitor plate after the filtering time has been too long and the foam from continuing to rise for an extended period due to thermal inertia, causing the foam to overflow from the heating container.

[0079] In Example 3, the height difference between the second electrode and the first electrode can be adjusted according to the usage scenario.

[0080] The height difference between the second electrode and the first electrode directly affects the range of foam height fluctuations. When the height difference between the second electrode and the first electrode is small, the foam can descend to the second electrode more quickly, resulting in faster power recovery and higher average power. When the height difference between the second electrode and the first electrode is large, the foam fully collapses before reheating, further ensuring that the foam is less likely to overflow.

[0081] In practical use, the height difference between the second and first electrodes can be set according to the type of beverage. For low-viscosity beverages (such as traditional Chinese medicine and herbal tea), the height difference between the second and first electrodes can be relatively small. For easily foaming or high-viscosity liquids (such as white fungus and rice porridge), the height difference between the second and first electrodes can be relatively large. For adjustable second and first electrodes, a preset mode can be selected for adjustment according to the type of liquid.

[0082] In Example 4, when adjusting the height difference between the second electrode and the first electrode, the position of the second electrode can be adjusted based on the position of the first electrode.

[0083] In this embodiment, multiple capacitor plates at different heights located below the first electrode plate constitute the first detection area; the control method selects and sets the second electrode plate from the first detection area according to the instructions of the liquid heater.

[0084] In this embodiment, a first detection zone is formed by multiple capacitor plates of different heights between the lower side of the first electrode and the liquid level. The control method selects and sets the second electrode from the first detection zone according to the instructions of the liquid heater. At this time, the first electrode is used as the upper limit of the foam rising height. The second electrode is set between the first electrode and the liquid level according to the height of the liquid level and the type of beverage, so as to adapt to different liquid levels as much as possible.

[0085] In some embodiments of this invention, 10 capacitor plates can be installed on the side wall of the heating container along its height, with a vertical spacing of 6mm between adjacent capacitor plates. The top capacitor plate can be initially designated as the first plate. When the "porridge" program is activated, the liquid level is detected, and the second capacitor plate above the liquid level is selected as the second plate. Porridge contains a significant amount of starch, making it more prone to foaming that is difficult to break. Therefore, the second plate is positioned closer to the liquid level to ensure thorough foam elimination.

[0086] In some embodiments of this invention, 10 capacitor plates can be installed along the height of the side wall of the heating container, with a vertical spacing of 6mm between adjacent capacitor plates. The top capacitor plate can be initially designated as the first plate. When the "milk" program is activated, the liquid level is detected, and the third capacitor plate above the liquid level is selected as the second plate. Milk contains a relatively high amount of fat and protein, and is prone to foaming, but the foam is relatively easy to break. Therefore, the second plate can be positioned relatively far from the liquid level to balance the bubbling of the beverage and prevent foam overflow.

[0087] In Example 5, when adjusting the height difference between the second electrode and the first electrode, the position of the first electrode can be adjusted based on the position of the second electrode.

[0088] In this embodiment, a second detection zone is formed by multiple capacitor plates of different heights between the upper side of the second electrode and the upper edge of the liquid heater. The control method selects and sets the first electrode from the second detection zone according to the instructions of the liquid heater. At this time, the set second electrode is used as the lower limit of the foam descent height. The first electrode is set between the upper side of the second electrode and the upper edge of the liquid heater according to the liquid level and the type of beverage, and the height of the first electrode is adjusted as much as possible according to different beverages.

[0089] In some embodiments of this example, the height of the first electrode can be adjusted according to the frequency or number of times the first electrode detects an overflow signal. For example, when using a heating container, 10 capacitor electrodes can be installed along the height direction on the side wall, with a vertical spacing of 8mm between adjacent capacitor electrodes. After detecting the liquid level, the capacitor electrode closest to and above the liquid level can be designated as the second electrode, and the second capacitor electrode from the top of the heating container downwards can be designated as the first electrode. When brewing beverages that easily produce foam, if the first electrode detects an overflow signal twice, the highest capacitor electrode can be selected as the first electrode, increasing the height difference between the first and second electrodes to ensure that the foam is fully eliminated.

[0090] Example 6: Verification of the test results of the second electrode and the first electrode.

[0091] To avoid interference with the second or first electrode in extreme cases, which could cause the heating container to misalign, reduce or restore heating power, ultimately resulting in insufficient heating of the beverage or overflow of foam.

[0092] Therefore, in some embodiments, when the second electrode no longer detects an overflow signal and the first electrode no longer detects an overflow signal, the heating container resumes heating. Through two levels of detection, interference in extreme cases (e.g., the electrode surface is briefly washed by droplets and then immediately blocked by air bubbles) is filtered out.

[0093] Similarly, in some embodiments, when the second electrode detects an overflow signal, and the first electrode detects an overflow signal, the heating container stops heating.

[0094] Example 7: The heating power is adjusted by calculating the time interval for triggering the anti-overflow mechanism, thereby achieving the optimal heating power to achieve the effect of continuous gentle boiling in beverage preparation.

[0095] Existing liquid heaters include a pre-boiling heating stage and a post-boiling simmering stage in the beverage preparation process. The pre-boiling heating stage typically uses higher heating power to quickly bring the beverage to a boil, shortening the heating time. The post-boiling simmering stage typically uses lower heating power to reduce the probability of foam overflow.

[0096] In existing technologies, liquid heaters use the same heating power during the cooking stage, regardless of the volume of the beverage. With the same heating power, small-volume beverages often boil violently, easily producing foam and overflowing, posing a safety hazard. Conversely, large-volume beverages often do not maintain a sustained boil, affecting the taste and the release of nutrients.

[0097] In particular, some existing liquid heaters have an anti-overflow function. For example, in patent CN201720159218.0, if a higher heating power is used during the boiling stage to improve the boiling effect, the anti-overflow function may be triggered frequently. Once triggered, the anti-overflow function will stop heating or halve the heating power during the boiling stage to achieve a defoaming effect. However, this existing technology directly halves the heating power or stops heating when the anti-overflow function is triggered, and cannot dynamically adjust the heating power according to the anti-overflow process, resulting in excessively long beverage preparation time.

[0098] Furthermore, to ensure the beverage remains boiled for as long as possible without overflowing, existing technologies, such as patent CN201810305012.3, reduce the heating time and / or heating power of the health pot based on the aforementioned anti-overflow signal and the cooking mode of the health pot. The heating state of the health pot is controlled according to the type of food, preventing overflow during cooking. Specifically, each time an anti-overflow signal is issued, the heating power of the health pot decreases by a rated value, namely the third preset power value. This results in a uniform decrease in heating power, thereby achieving relatively accurate control of the heating temperature of the health pot. For example, in patent CN200910016091.7, the process of judging tn after the slurry touches the anti-overflow electrode is described. By judging tn, the actual heating power Pn of the heating device for heating the slurry is determined. Pn is variable, and the range of Pn is 0 < Pn ≤ Pe. After the slurry touches the anti-overflow electrode, the reference value of the heating power of the heating device is P1, and P1 < Pe. Pn changes based on P1. Pn heats the slurry in an increasing or decreasing state. The adjustment value of the increasing or decreasing heating power is ΔP. ​​If tn ≤ t, then the actual heating power of the heating device for heating the slurry is Pn+1 = Pn + ΔP; if tn > t, then the actual heating power of the heating device for heating the slurry is Pn+1 = Pn - ΔP, and 0 ≤ ΔP < P1. This ensures that the slurry is always in a heated state throughout the entire boiling process.

[0099] The aforementioned existing technology reduces the heating power by a fixed value each time the anti-overflow mechanism is triggered, until it reaches the set lower limit. However, for different types and volumes of beverage slices, the existing technology's fixed-rate adjustment method makes it impossible to accurately adjust the heating power. The existing technology may be constantly changing between increasing and decreasing the heating power, thus the liquid heater cannot regulate the time when the ingredients in the beverage generate foam to trigger the anti-overflow mechanism, nor can it achieve a dynamic balance of continuous boiling without overflow.

[0100] Therefore, in some implementations, in order to solve the problem that in the prior art, the heating power decreases by a fixed value each time the anti-overflow is triggered, so that the liquid heater cannot adjust the time when the beverage foam triggers the anti-overflow, and the liquid heater cannot achieve a dynamic balance of continuous boiling of the beverage without overflow.

[0101] In some implementations, by calculating the ratio of the time interval tn to the preset target time T, the adjustment amount of the heating power is different each time the heating power of the heating container is adjusted during the cooking stage, thereby flexibly and dynamically adjusting the heating power during the cooking stage. For example... Figure 4 As shown, a fixed preset target time T can be used, including the following implementation methods: 1. Heating is performed with the heating power of the cooking stage of P1, and the timing starts after the anti-overflow is triggered for the first time during the cooking process;

[0102] 2. Continue heating at the heating power of P1 during the cooking stage. After the anti-overflow is triggered for the second time during the cooking process, stop the timer and record the time t1. Then adjust the heating power of the cooking stage to P2 and restart the timer.

[0103] 3. Continue heating at the heating power of P2 during the cooking stage. After the anti-overflow is triggered for the third time during the cooking process, stop the timer and record the time as t2s. Then adjust the heating power of the cooking stage to P3 and restart the timer.

[0104] 4. Continue heating at the power of Pn during the cooking stage. After the anti-overflow is triggered for the nth time during the cooking process, stop the timer and record the time tn. Then adjust the heating power of the cooking stage to Pn. The time units of t1, t2...tn and T are seconds, and T is the target time. The target time T can be selected as 20 seconds. <T<40s。

[0105] The heating power for the final cooking stage can be Pn.

[0106] In this implementation method, for example, if t1≤T, the heating power of the cooking stage is reduced; if t1>T, the heating power of the cooking stage is increased. After adjusting the power, the next time interval t2 for triggering the anti-overflow should be around T, indicating that the heating power at this time can trigger the anti-overflow around Ts. Therefore, the power can be adjusted further. Finally, through the above method, Pn can be quickly found, and cooking can be carried out with Pn as the heating power of the cooking stage. The heating power of this cooking stage can maintain a continuous simmering effect. The heating power of this cooking stage can achieve the optimal heating power for different capacities and different ingredients, and will not cause overflow due to the thermal inertia of the heating element.

[0107] This implementation compares the actual anti-overflow trigger time tn with a preset target time T, and flexibly adjusts the heating power of the heating element in the heating container based on the ratio tn / T. The preset target time T is an adjustable value that can be adjusted according to the preparation process, beverage volume, or user needs, ultimately bringing the anti-overflow trigger time tn close to the preset target time T. Compared to existing technologies where the heating power decreases by a fixed value each time, this implementation dynamically adjusts the heating power based on a time ratio. This allows the liquid heater to dynamically adjust the time when the beverage foam triggers anti-overflow, providing a smooth power adjustment curve. Furthermore, the liquid heater can achieve a dynamic balance where the beverage boils continuously without overflowing.

[0108] In some implementations, a varying preset target time n*T may also be used, such as... Figure 5 As shown, the following implementation methods are included:

[0109] 1. Heating is performed using the heating power of P1 during the cooking stage, and the timer starts after the anti-overflow is triggered for the first time during the cooking process;

[0110] 2. Continue heating at the heating power of P1 during the cooking stage. After the anti-overflow is triggered for the second time during the cooking process, stop the timer and record the time t1. Then adjust the heating power of the cooking stage to P2 and restart the timer.

[0111] 3. Continue heating at the heating power of P2 during the cooking stage. After the anti-overflow is triggered for the third time during the cooking process, stop the timer and record the time as t2s. Then adjust the heating power of the cooking stage to P3 and restart the timer.

[0112] 4. Continue heating at the power of Pn during the cooking stage. After the anti-overflow is triggered for the nth time during the cooking process, stop the timer and record the time tn. Then adjust the heating power of the cooking stage to Pn. The time units of t1, t2...tn and T are seconds, where s is the second and T is the target time. The heating power of the cooking stage is Pn.

[0113] This implementation compares the actual anti-overflow trigger time tn with a preset target time n*T, and flexibly adjusts the heating power of the heating element in the heating container based on the ratio tn / T. Here, n*T means that after each power adjustment, the preset target time n*T is increased, thus reducing the amount of power adjustment each time, achieving more precise dynamic adjustment, and ultimately gradually approaching a heating power that continuously boils while triggering the anti-overflow mechanism. Compared to existing technologies where the heating power decreases by a fixed value each time, this implementation dynamically adjusts the heating power based on a time ratio. Therefore, the liquid heater can adjust the time when beverage foam triggers the anti-overflow mechanism, and the liquid heater can further achieve a dynamic balance where the beverage continuously boils without overflowing.

[0114] When the preset target time T is too large or too small, it will cause the adjustment range of the heating power in the boiling stage to be too large. In some implementation manners of the above embodiments, since the heating power in the boiling stage is not adjusted, the anti-overflow time is triggered at about 30 s. It is preferable to set the preset target time T to 20 s ≤ T ≤ 40 s.

[0115] To prevent the heating power in the boiling stage from being adjusted too high or too low, in some implementation manners, the initial power P1 range and the heating power Pn range in the boiling stage can be determined by identifying the capacity through specific heat capacity. For example: 1. Heat at the rated power P, and start timing when the water temperature reaches 40°C;

[0116] 2. When the water temperature Temp reaches 70°C, stop timing and record the time t. When calculating the production capacity through specific heat capacity, select 40°C - 70°C. If the calculation starts below 40°C, then when the user adds water in summer, the temperature may exceed this value, resulting in inaccurate measured capacity. If the timing stops above 70°C, then if there are ingredients that already produce foam at this temperature and the heating is stopped to prevent overflow, it will also cause inaccurate measured capacity.

[0117] 3. Obtain the production capacity m from the formula P * t = C * m * ΔT;

[0118] 4. If m > 1500 ml, the initial power P1 should satisfy 800 W < P1 ≤ 1000 W, and Pn should satisfy 200 W < Pn ≤ 300 W; if 900 ml < m < 1500 ml, the initial power P1 should satisfy 600 W < P1 ≤ 800 W, and Pn should satisfy 150 W < Pn ≤ 250 W; if 500 ml < m < 900 ml, the initial power P1 should satisfy 400 W < P1 ≤ 600 W, and Pn should satisfy 100 W < Pn ≤ 150 W; if m < 500 ml, the initial power P1 is set to 400 W, and Pn should satisfy 50 W < Pn ≤ 150 W. In the heating-up stage, the larger the capacity, the greater the energy required for heating up, the slower the heating-up speed, and the longer the time required to reach the boiling point, which will affect the entire production time; however, the initial power cannot be too large, otherwise it will cause uneven heating of the ingredients and easy pasteurization of the ingredients. In the boiling stage, the larger the capacity, the greater the energy required to maintain continuous boiling, and relatively large power is required for boiling; the smaller the capacity, the smaller the energy required to maintain continuous boiling, and relatively small power is required for boiling;

[0119] In some implementation manners, from the start of heating until the water temperature Temp is lower than 70°C, the heating container is heated at the initial power P1.

[0120] In some embodiments, anti-overflow detection is not performed from the start of heating until the water temperature Temp is lower than 70°C. Premature anti-overflow detection may prematurely cause interference noises such as condensed water, leading to premature adjustment of the power to the heating power range of the optimal boiling stage for the current capacity. However, the temperature at this time is still relatively far from the boiling point, resulting in an extended beverage production cycle.

[0121] In some embodiments, when the water temperature is 70°C < Temp < boiling point, even if Pn meets the condition in point 4, the heating power Pn in the boiling stage continues. When the water temperature is (boiling point - 1°C) < Temp < boiling point and lasts for 3 minutes, it means the temperature has stabilized. At this time, if the adjusted boiling power meets the heating power range of the optimal boiling stage for the current capacity, the adjustment of the heating power in the boiling stage stops. There is still a certain amount of time within 3 minutes close to the boiling point to adjust and optimize the heating power in the boiling stage to find the optimal heating power in the boiling stage.

[0122] In some embodiments, 6. When a) the water temperature is (boiling point - 1°C) < Temp < boiling point, b) it is maintained at this previous temperature for 3 minutes, and c) the current boiling power Pn meets the condition in point 4, then the adjustment of the boiling power stops.

[0123] 7. When the power boiling time for which the adjustment of the boiling power stops as per point 6 exceeds 5 minutes, the adjustment of the boiling power is started. In different boiling stages, the characteristics of the ingredients will vary, and the foaming pattern will also change. Therefore, a 5-minute timeout is set to callback the boiling power, and the adjustment is made again to find a better boiling power to ensure the effect of continuous boiling and appropriately increase the boiling power to further enhance the boiling effect.

[0124] In some embodiments, for the timing when the adjusted heating power in the boiling stage starts to be used, the following scheme can be adopted:

[0125] 1. When the liquid heater uses a contact electrode, after detecting that the foam has left the anti-overflow electrode rod, wait for 30 seconds and then start using the adjusted heating power in the boiling stage. To prevent starting to heat with the adjusted heating power in the boiling stage before the foam has fallen back after stopping heating, which would result in a shorter time until the next anti-overflow trigger and affect the adjustment of the heating power in the boiling stage, waiting for 30 seconds is used to force the foam to fall back.

[0126] 2. When the liquid heater uses a non-contact capacitive electrode, if the capacitance of the foam trigger electrode 101 is detected to be 80%, the adjusted heating power for the cooking stage is applied. The optimized power is only applied after the foam has subsided to 80% of the current capacitance of the trigger electrode 101. If foam adheres, a relatively lower optimal cooking stage heating power Pn is used. This allows for both lower power heating to defrost the foam and prevents significant overflow if it occurs.

[0127] 3. If the contact electrode is not removed or the capacitance of the capacitor plate is not reached within 1 minute, the electrode plate 101 is considered to be stuck. If sticking is detected, the heating power Pn of the optimal cooking stage is directly used until conditions 1 and 2 are met.

[0128] Example 8.

[0129] In some implementations, heating is stopped when foam is detected on the highest capacitor electrode or any lower capacitor electrode, where the detection threshold differs for capacitor electrodes of different heights. The purpose is to ensure a rapid response to prevent overflow.

[0130] In existing technologies, the initial anti-overflow technology immediately changes the operating state of the liquid heater to prevent foam from overflowing from the heating container when a single electrode or the top anti-overflow electrode detects foam. However, if the single electrode or the top anti-overflow electrode fails, the anti-overflow function of the liquid heater will also fail.

[0131] To address the technical problem of overflow prevention failure in liquid heaters, existing technology CN202020236639.0 proposes a reliable overflow prevention commercial food processor. The machine's interior contains a first overflow prevention electrode and a second overflow prevention electrode, with the first electrode positioned lower than the second. An MCU controls the power switch circuit to disconnect based on an overflow signal from either electrode, achieving dual protection. However, the existing technology uses two overflow prevention electrodes with the same threshold value. In practice, when the first overflow prevention electrode is functioning correctly, the liquid heater disconnects before the foam reaches the second electrode. In other words, the existing second overflow prevention electrode only functions when the first electrode is damaged.

[0132] In addition, foam of different heights has different size and density, and the density and size of the foam also change frequently. The threshold values ​​of the first and second anti-overflow electrodes are the same. If the electrodes are not sensitive enough to the foam, they may not be able to respond in time to smaller or sparser foam. Conversely, if they are too sensitive, they may misjudge larger or denser foam, leading to unnecessary power outages.

[0133] Therefore, in some implementations, in order to solve the technical problem that when using multiple capacitor electrodes, the existing technology detects overflow based on a single height capacitor electrode or a single threshold, and the foam concentration varies at different heights, resulting in insufficient sensitivity or easy misjudgment in foam detection.

[0134] In some implementations, the workflow for preparing beverages with ingredients using a liquid heater can be as follows.

[0135] 1. Start the liquid heater: The user places the ingredients and water into the heating container of the liquid heater according to the required ratio, and selects the corresponding cooking program to start the liquid heater. In some implementations, the threshold value of the control chip for capacitor plates of different heights can be adjusted according to the cooking program.

[0136] 2. Heating process: The health pot starts heating the inner pot, gradually raising the water temperature to prepare drinks with ingredients. For some liquid heaters, the heating process is accompanied by blades or stirring pieces to crush or stir.

[0137] 3. Liquid level and foam detection (hereinafter referred to as overflow prevention detection): As heating progresses, the beverage begins to produce foam. The capacitor plate detects the foam and, in conjunction with the control chip and heating container, prevents the foam from overflowing. Overflow prevention detection can begin at the start of heating, after the beverage reaches boiling point, or at any stage of beverage preparation.

[0138] 4. Production process stops and keeps warm: Once the production process is complete, the liquid heater will usually automatically switch to keep warm mode to ensure that the beverage is kept at a suitable temperature until the user is ready to consume it.

[0139] like Figure 1 As shown in the diagram, in some embodiments, the specific overflow prevention detection process for the liquid heater is as follows:

[0140] 1. The control chip has different thresholds for the original signals generated by capacitor plates of different heights, and the control chip detects the original signals generated by capacitor plates of different heights;

[0141] 2. If the control chip detects that the original signal generated by any of its capacitor plates exceeds its threshold, it determines that there is a risk of overflow from the liquid heater;

[0142] 3. When the control chip determines that there is a risk of overflow from the liquid heater, the control chip can prevent foam overflow by adjusting the heating power of the heating container, including reducing the heating power of the heating element or stopping heating directly;

[0143] 4. Resume heating: When the original signal of the capacitor electrode is lower than its threshold, the control chip will restore or gradually restore the power of the heating element to continue the beverage making process.

[0144] In some implementations, the threshold for the control chip to determine the original signal can be set in the following ways.

[0145] 1. Set the reference value of the original signal of the capacitor electrode: Measure the reference value of the original signal of the capacitor electrode in a dry state or in a state with only liquid and no foam under heating container.

[0146] 2. Measure the original signal generated by capacitor electrodes at different heights under different foam concentrations (different foam sizes and densities). Due to the presence of foam, the generated original signal is usually lower than that in a pure liquid state.

[0147] 3. Different capacitor electrode thresholds can be preset for each cooking process to match the foaming characteristics and speed of different ingredients, thus adapting to different ingredients and cooking needs.

[0148] The capacitor electrodes can also be layered according to different heights, with each layer having a specific threshold. Each layer's height corresponds to a different foam concentration. For example, a threshold gradient can be set for the capacitor electrodes, with the threshold increasing as the height increases. For taller electrodes, the threshold is lower because the foam concentration is lower towards the top, resulting in weaker changes in the original signal. Conversely, for shorter electrodes, the threshold is higher because the foam concentration is higher closer to the liquid surface, making changes in the original signal more pronounced. Furthermore, shorter electrodes are more susceptible to noise interference from liquid churning, so a higher threshold is needed to reduce interference.

[0149] The control chip can also filter or delay the original signal to avoid frequent fluctuations in the original signal caused by interference noise such as condensation. The filtering time for capacitor plates of different heights can be different or the same; preferably, the filtering time gradually shortens as the height increases. The control chip can also adjust the heating power of the heating container after the strength of the original signal meets the threshold and the delay time is satisfied, thus preventing foam overflow. The delay time required for capacitor plates of different heights can be the same or different; preferably, the delay time is required to gradually shorten as the height increases, so as to respond promptly to the anti-overflow signal and stop heating, preventing the foam from reaching the height of the top capacitor plate, where the filtering time is too long and thermal inertia causes the bubbles to continue rising for a longer period, resulting in foam overflowing the heating container.

[0150] In summary, this embodiment uses multiple capacitor plates with different threshold values ​​for plates at different heights, thereby enabling the detection of varying concentrations at different heights and the continuous change in foam concentration. Furthermore, if the original signal generated by a capacitor plate at any height exceeds its threshold, the heating power is adjusted to quickly respond to changes in foam concentration and reduce the risk of foam overflow.

[0151] In some implementations, besides detecting the top capacitor electrode, only the second capacitor electrode below the top capacitor electrode is detected during the testing process. This further simplifies the entire testing process, allowing focus on areas most likely to overflow or pose a safety risk. The second capacitor electrode below the top capacitor electrode is selected for two reasons: firstly, to increase the distance between the two selected capacitor electrodes, preventing them from being adjacent and simultaneously affected by condensation; and secondly, to prevent the distance between the two capacitor electrodes from being too large, causing the lower capacitor electrode to be too close to the liquid surface, reducing accidental foaming at the bottom or middle of the heating container that could cause misjudgment by the liquid heater, thus improving the continuity and stability of the cooking process.

[0152] Example 9.

[0153] To achieve more accurate detection, existing designs often install multiple detection components inside the steam valve seat at the top of the heating container, thereby improving judgment accuracy. For example, patent CN201621100798.8 describes a design where two foam detection components are installed inside the steam valve seat. The height of the first foam sensing component A is lower than the height of the second foam sensing component B. If the main control chip only receives the first foam detection signal, meaning only the capacitance value of the first foam sensing component A changes, it determines that boiling is insufficient and the electric cooker has not overflowed. The main control chip then controls the electric cooker to maintain its current output power. If the main control chip receives the second foam detection signal after receiving the first, meaning both the capacitance values ​​of the first and second foam sensing components A and B change, it determines that boiling is sufficiently vigorous and the electric cooker is about to overflow. It then controls the current output power of the electric cooker to decrease or stops heating to prevent steam foam from overflowing. This ensures sufficient boiling without causing overflow.

[0154] In this prior art, the two sensing components are at different heights and there is a gap between them. However, both sensing components are located inside the steam valve seat, and they both detect the foam inside the top steam valve seat. The distance between the sensing components is limited, making it impossible to detect the area between the steam valve seat and the liquid surface, thus limiting the foam detection range.

[0155] Furthermore, although existing technologies also use non-contact capacitive sensing components, these components are located inside the steam valve seat at the top of the heating container. The steam generated during heating is discharged through the steam valve seat, and the temperature difference between the sensing component and the steam inside the steam valve seat is small, making it less prone to condensation. Therefore, the sensing component is less affected by interference signals from condensation.

[0156] To further improve the accuracy of foam detection, existing technologies employ multiple non-contact anti-overflow electrodes mounted on the outside of the heating container. In this embodiment, a capacitor plate is provided on the outer wall of the heating container. This capacitor plate is a non-contact capacitor plate, forming a detection area on the inner wall of the heating container. Changes in the medium within the detection area generate different initial signals. When there is no water on the inner wall of the heating container where the capacitor plate is located, the medium of the capacitor plate is air, which has a relatively low dielectric constant. When there is water on the inner wall of the heating container, the initial signal generated by the capacitor plate will be stronger. Thus, the liquid heater determines whether foam generated by the food has overflowed by using the initial signal output by the capacitor plate.

[0157] As in the existing technology CN202410210628.8, multiple capacitor plates are longitudinally installed on the outer wall of the pulping container, which makes the detection of foamy slurry overflow signals generated during the pulping process more reliable. It can more effectively identify the overflow prevention signal and is less likely to pose a safety risk of overflow of bubble or foamy slurry.

[0158] However, during beverage preparation, the inner wall of the heating container is usually cooler than the steam, causing steam to easily condense on the detection area of ​​the container's inner wall. For non-contact capacitors, this condensation alters the original signal generated by the capacitor, leading to misjudgments by the liquid heater. For foam detection, besides noise interference from condensation, food residue can also cause noise interference.

[0159] Therefore, in some embodiments, in order to solve the technical problem that the existing technology has capacitor plates on the outer wall of the heating container, and the capacitor plates generate condensate in the detection area on the inner wall of the heating container, which can easily lead to misjudgment by the liquid heater and affect the heating speed.

[0160] To reduce noise interference from condensate or other interfering signals on the detection of the capacitor plates and the judgment of the control chip, the control chip continuously monitors the capacitance change of the top capacitor plate. When the capacitance of the top capacitor plate increases rapidly, the control chip checks whether the capacitor plates below also show a similar capacitance change trend, thus determining the rising speed of the foam and whether the foam is stabilizing. Compared to existing technologies, after the control chip determines that the foam has reached the top capacitor plate, it performs a re-inspection of the capacitor plates below, thereby improving the anti-interference capability of the liquid heater in detecting foam overflow.

[0161] During the heating process described above, after the liquid heater starts heating the inner liner, the water temperature gradually rises to prepare the beverage with ingredients, and condensation forms on the inner wall of the heated container.

[0162] like Figure 2 As shown in the diagram, in some embodiments, the specific overflow prevention detection process for the liquid heater is as follows:

[0163] 1. Initial detection of foam height: The control chip first detects the original signal generated by the capacitor plate at the top of the liquid heater. The control chip determines whether the original signal of the capacitor plate at the top exceeds its threshold to initially confirm whether there is a risk of overflow.

[0164] 2. Re-inspection of foam height: If the original signal of the top capacitor exceeds its threshold, the control chip will further detect the original signal of one or more capacitors below the top capacitor to reduce noise interference such as condensation.

[0165] 3. Response measures: If the original signals of the capacitor plates at the top and bottom both exceed the threshold, the control chip can prevent foam overflow by adjusting the heating power of the heating container, including reducing the heating power of the heating tube or stopping heating directly.

[0166] 4. Resume heating: If the original signal of the capacitor plate at the top is lower than its threshold, the control chip will restore or gradually restore the power of the heating element to continue the beverage making process.

[0167] In summary, in this embodiment, when the original signal of the top capacitor exceeds the threshold, the control chip will further detect the original signals of one or more capacitors below the top capacitor. Only when the original signal of the capacitor below the top capacitor exceeds the threshold will the heating power be reduced, thereby improving the accuracy and reliability of the judgment; avoiding stopping heating due to noise interference from condensate water, thus avoiding frequent adjustments to the heating state.

[0168] Furthermore, the detection sequence in this embodiment is from top to bottom, which can quickly identify the risk of high-level foam accumulation. Once foam is detected at the highest point, it indicates that the foam has approached or reached a dangerous height where it may overflow. Then, a more in-depth inspection (the original signal of the capacitor electrode below the top capacitor electrode) is performed, which can respond to high-level foam accumulation more quickly. It also reduces the data processing requirements of the control chip before the foam reaches the detection area of ​​the top capacitor electrode.

[0169] In some implementations, the control chip can determine whether a foam has reached the detection area of ​​the capacitor electrode by comparing a threshold with the original signal of the capacitor electrode. The control chip can also determine whether a foam has reached the detection area of ​​the top capacitor electrode by comparing whether the original signals of the top capacitor electrode and the capacitor electrode below the top electrode increase simultaneously.

[0170] In some implementations, besides detecting the top capacitor electrode, only the second capacitor electrode below the top capacitor electrode is detected during the testing process. This further simplifies the entire testing process, allowing focus on areas most likely to overflow or pose a safety risk. The second capacitor electrode below the top capacitor electrode is selected for two reasons: firstly, to increase the distance between the two selected capacitor electrodes, preventing them from being adjacent and simultaneously affected by condensation; and secondly, to prevent the distance between the two capacitor electrodes from being too large, causing the lower capacitor electrode to be too close to the liquid surface, reducing accidental foaming at the bottom or middle of the heating container that could cause misjudgment by the liquid heater, thus improving the continuity and stability of the cooking process.

[0171] Example 10.

[0172] In some implementations, due to the diverse needs of daily life, health-preserving kettles are popular for their multiple recipes and processes. Currently, most health-preserving kettles support cooking functions such as porridge, desserts, and soups. However, the addition of these functions has led to various problems during the cooking process. For example, recipes with high gelatinous content, such as porridge with white fungus, are prone to foaming and overflowing. To address this, current health-preserving kettles on the market stop heating for 15 seconds to allow the foam to subside, thus preventing overflow. Alternatively, they use electrode detection to stop heating when high foam levels are detected. However, because heating is stopped, the food is not continuously boiling and bubbling, which fails to effectively extract the nutrients from the food. For example, in the mung bean soup function, the intermittent heating due to the overflow prevention requirement makes it difficult to break down the mung bean skins, resulting in mostly slow cooking with little sand. To solve this problem, this technology proposes a continuous bubbling cooking method to increase the extraction of nutrients from cooked food.

[0173] A cooking method that involves continuous tumbling during the cooking process in a health pot to increase the release of nutrients from food after cooking.

[0174] In some implementations, the electrode on the lid of the health pot is used to detect whether there is an overflow signal. If an overflow signal is detected, the power of the heating element is reduced but heating is not stopped. If no overflow signal is detected, high-power heating is used.

[0175] In the above embodiments, the health pot includes a base consisting of a bottom cover, a circuit board, a middle cover, a top cover, and a coupler, and a pot body consisting of an electrode moving contact, an electrode rod 1, an electrode connecting piece, a pot handle 2, a pot body, a temperature sensor, and a coupler.

[0176] The power supply section of the aforementioned circuit board is a safety isolated power supply. The GND output of the circuit board power supply is connected to the safety ground PE of the plug through a 1Ω resistor. The housing of the temperature sensor in the aforementioned kettle body is connected to the common ground PE. The aforementioned circuit board integrates a control unit MCU. The aforementioned electrode rod 1 is connected to the electrode connecting piece through the electrode moving contact and then connected to the circuit board through a coupler via a wire.

[0177] ① During the cooking process of mung beans, first heat to 85℃ using a fixed 850W, then heat to 88℃ using 650W, and then heat to 93℃ using 300W. After reaching 93℃, continue heating at a fixed power of 250W for 5-20 minutes, during which time heat at 50W for 15 seconds every 5 minutes, then continue heating at 200W, during which time heat at 50W for 10 seconds every 5 minutes, until cooking is complete.

[0178] ② During the cooking process of white fungus, first heat it to 85℃ using a fixed 850W, then heat it to 88℃ using 650W, and then heat it to 91℃ using 300W. After reaching 91℃, heat it continuously at a fixed 200W power for 15 seconds, then at a fixed 250W power for 5 seconds. During this period, heat it at 50W power for 15 seconds every 2 minutes, then continue heating at 200W power, with 50W power heating for 10 seconds every minute, until cooking is complete.

[0179] If foam overflows and comes into contact with electrode rod 1 during the process, the MCU will control the heating plate to reduce its power to 50W. Eight seconds after the contact protection ends, the power will resume operation as described in ① or ② above.

[0180] If the electrode probe detects continuous foaming for more than 39 seconds, the power of either ① or ② above will be reduced by 50W for heating.

[0181] If electrode rod 1 detects continuous foaming for more than 60 seconds without the foam dissipating, the power of either ① or ② mentioned above will be reduced to approximately 125W for heating. The power will be restored to either ① or ② once the electrodes detect the foam has subsided.

[0182] With the above scheme, when the foam generated by the boiling food in the pot comes into contact with the electrode rod 1, the electrode rod 1 connects to the temperature sensor at the bottom through the foam to form a circuit loop, thereby detecting the overflow signal.

[0183] During the cooking process, a temperature sensor detects the current temperature of the food. When the temperature is too low, it is heated to a fixed temperature at high power. Once the food reaches the fixed temperature, the power is reduced to between 150 and 250W for continuous heating, with the initial power being higher to ensure the food boils as quickly as possible, while also ensuring that the food boils and tumbles continuously in the early stages to prevent it from piling up at the bottom of the pot and burning.

[0184] If foam overflows and comes into contact with electrode rod 1 during the process, it indicates that the current power is too high and the boiling is too intense. The MCU controls the power to be reduced to 50W for heating. The residual heat of the heating plate and the low power of 50W are used to continuously replenish the heat to ensure that the food can continue to tumble. After the foam subsides, the power is restored to normal after 8 seconds.

[0185] If the electrode probe detects continuous foaming for more than 39 seconds, and the foam subsides between 39 and 60 seconds after touching the electrode, it indicates that the food contains a lot of gelatinous substances and the foam subsides very slowly. In this case, reduce the power of ① or ② by 50W for heating. This will ensure that the food continues to boil and tumble while preventing the food foam from touching the electrode probe 1 too quickly.

[0186] When electrode rod 1 detects continuous foaming for more than 60 seconds, and continues to detect foam overflowing after 60 seconds, it is determined that the food contains a high amount of gelatinous material, and this gelatinous liquid has already left residue on the electrodes and the pot wall, causing electrode rod 1 to form a circuit loop with the temperature sensor housing. At this point, to ensure continuous boiling, the power of ① or ② will be reduced to approximately 125W. At this power, the food will slowly boil and tumble without overflowing excessively.

[0187] Example 11.

[0188] Make a hole at the connection between the kettle body and the handle 2, pass the electrode rod 1 through the hole and connect it to the coupler through a wire.

[0189] The electrode rod 1 is positioned horizontally at a distance of 10 mm ± 1 from the horizontal position of the spout of the kettle, and the distance between the electrode rod 1 and the glass is [missing information].

[0190] The inner surface of the pot is bent at 7.7mm±1mm with a 90° angle and extended downwards by 12.5mm±1mm. The electrode rod 1 is connected to one side of the pot body with a threaded connection. The threaded connection is 4.5mm±0.5mm long, and a fixing platform is made at the bottom of the threaded connection. The electrode rod 1 is fixed to the glass pot body with a nut.

[0191] The above solution can reduce the contact resistance when the moving electrode contact is connected to the electrode plate 101, and reduce the failure of the anti-overflow detection caused by poor contact. By bending the electrode rod at 17.7mm at a 90° angle, the foam will first contact the electrode rod 1 when it overflows during cooking, reducing the contamination of the electrode by foam residue and preventing the electrode from sticking together for a long time during cooking.

[0192] In some embodiments, the electrode rod 1 is modified to extend downwards in a flat plane, with a rubber pad 103 at the bottom (as shown in the attached figure). Figure 5 (As shown)

[0193] In the above embodiment, the electrode sheet 101 is modified to have a length of 9.5mm ± 0.5mm and a width of 6mm ± 0.5mm, with rounded edges on both sides. The electrode sheet 101 and the threaded post 102 are integrally formed, with the connection point located at the center of the upper rounded edge. A rubber pad 103 is placed behind the electrode sheet 101, and the shape of the rubber pad 103 conforms closely to the surface of the pot body. The thickness of the rubber pad 103 is 1mm ± 0.5mm at its thinnest point and 2mm ± 1mm ​​at its thickest point. The above pad is made of silicone material with good hydrophobicity.

[0194] The technical problems solved and the technical effects achieved (analyzed from the perspectives of the reasons for solving the problems and the working principles):

[0195] The above solution can reduce the cleaning difficulties caused by electrode posts and electrode platforms. The electrode sheet 101+ pad fits tightly with the glass pot body, making it easier to clean the pot body.

[0196] The aforementioned hydrophobic silicone pad 103 has a bottom height of 2mm. During cooking, if foam overflows over the electrodes, the 2mm height difference can effectively isolate residue, preventing it from adhering to the bottom and forming a circuit. It also prevents condensation from creating a circuit.

[0197] Furthermore, it should be noted that the liquid heater of the present invention is not limited to the food processing machine with an integrated motor and cup body disclosed in the embodiments of the present invention. It can also be a soy milk maker with a top-mounted motor, 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 the present invention can also be applied to heating appliances that can perform boiling operations, rice paste making, etc., such as health pots and health cookers.

[0198] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a liquid heater, the liquid heater comprising a heating container and a plurality of capacitor plates disposed on the outer wall of the heating container, the plurality of capacitor plates being arranged along the height direction of the heating container, the capacitor plates being used to detect overflow signals, the control method being characterized in that: The capacitor electrode has a first electrode and a second electrode respectively positioned above the initial liquid level of the beverage, with the first electrode being higher than the second electrode. When the first electrode detects an overflow signal, the heating container reduces its heating power; When the second electrode no longer detects an overflow signal, the heating container resumes heating power.

2. The control method for a liquid heater according to claim 1, characterized in that: Between the lower side of the first electrode and the liquid level, multiple capacitor electrodes of different heights constitute the first detection area; The control method selects and sets the second electrode from the first detection zone according to the instructions of the liquid heater.

3. The control method for a liquid heater according to claim 1, characterized in that: Between the upper side of the second electrode and the upper edge of the liquid heater, multiple capacitor electrodes of different heights constitute the second detection area; The control method selects and sets the first electrode from the second detection zone according to the instructions of the liquid heater.

4. The control method for a liquid heater according to claim 1, characterized in that: When the second electrode no longer detects an overflow signal and the first electrode no longer detects an overflow signal, the heating container resumes heating.

5. The control method for a liquid heater according to claim 1, characterized in that: When the second electrode detects an overflow signal, and the first electrode detects an overflow signal, the heating container stops heating.

6. The control method for a liquid heater according to claim 1, characterized in that: In the initial state, the first electrode is the capacitor electrode at the highest position of the heating container.

7. The control method for a liquid heater according to claim 1, characterized in that: When the first electrode detects an overflow signal, the heating container stops heating.

8. A method for controlling a liquid heater, comprising the method for controlling a liquid heater as described in any one of claims 1-7, characterized in that: The heating power is dynamically adjusted by calculating the time interval t between the detected overflow signal.

9. The control method for a liquid heater according to claim 8, characterized in that: The ratio of t to the target time T is used as the adjustment coefficient α. The current heating power is multiplied by α to obtain the dynamic adjustment power for the next stage, and the new power is applied after the anti-overflow release condition is met.

10. A control method for a liquid heater according to claim 9, characterized in that: The target time T increases with the number of times the overflow signal is detected; or, The target time T is a fixed value.

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