Liquid heater

Abstract

The utility model discloses a liquid heater, which belongs to the field of life electric appliances, solves the problem that the reliability is reduced due to the fact that an anti-overflow function and a cover closing detection function are independently realized, and adopts the technical scheme that the sampling end of a voltage sampling circuit is electrically connected with an AD (Analog to Digital) port of a control chip; the kettle body is provided with an upper coupler, a first terminal and a second terminal, the kettle body is arranged on the base to enable the upper coupler to be electrically connected with the lower coupler, the first terminal is electrically conducted with the upper coupler, the second terminal is connected with a divider resistor in series and then is grounded, the kettle cover is provided with an anti-overflow electrode and an electrode connecting piece which are electrically conducted with each other, and the kettle cover covers the kettle body in place. The output end of the voltage sampling circuit is sequentially connected with the lower coupler, the upper coupler, the first terminal, the electrode connecting piece, the second terminal and the divider resistor in series to form a detection circuit. The anti-overflow circuit is mainly used for rapidly judging the working reliability of the anti-overflow circuit during a product delivery test.

Description

Technical Field

[0001] The utility model relates to a household electrical appliance, in particular to a liquid heater. Background Art

[0002] In order to achieve overflow prevention detection, existing liquid heaters such as electric kettles and health kettles generally adopt two methods. One is to install the overflow prevention electrode on the top of the kettle body. The overflow prevention electrode cannot be disassembled, which is inconvenient to clean and easily forms a sanitary dead corner around the overflow prevention electrode, such as the health kettle disclosed in CN208573455U. The other is to install the overflow prevention electrode on the kettle lid. The overflow prevention electrode can be separated from the kettle body along with the kettle lid, which is convenient for users to clean, such as the food processor disclosed in CN209091009U. In the latter method, the overflow prevention circuit connected to the overflow prevention electrode is electrically connected through the contact between the coupling terminal and the coupling connecting piece. During use, if the kettle lid is not placed or the kettle lid is not placed in place, the coupling terminal and the coupling connecting piece are not in effective contact, and the overflow prevention circuit is not turned on and is in a failed state, affecting the user's experience. Therefore, the product is generally tested before leaving the factory to determine whether the overflow prevention function is normal.

[0003] At the same time, in order to detect whether the pot lid is placed in place, the liquid heater will also be provided with a lid closing detection circuit. For example, the food processor disclosed in CN209091009U is specially provided with a lid opening detection circuit, but it and the anti-overflow circuit each realize their separate functions, which requires increasing the number of electrical connection cores of the upper and lower couplers, and also requires using the AD ports of the two control chips for separate sampling, which reduces the overall reliability and generally increases the production cost of the product. Utility Model Content

[0004] The purpose to be achieved by the present utility model is to provide a liquid heater which solves the problem of reduced reliability caused by the independent implementation of the anti-overflow function and the lid closing detection function. When the product is tested at the factory, the working reliability of the anti-overflow circuit can be quickly judged to ensure the effectiveness of the anti-overflow function and the lid closing detection function, thereby ensuring that users have a good user experience. At the same time, the anti-overflow function and the lid closing detection function can be simultaneously implemented through a single circuit, thereby reducing the production cost of the product.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a liquid heater comprises a base, a kettle body and a kettle lid, the base is provided with a control circuit board and a lower coupler, the control circuit board has a control chip and a voltage sampling circuit, and the sampling end of the voltage sampling circuit is electrically connected to the AD port of the control chip; the kettle body is provided with an upper coupler, a first terminal and a second terminal, the kettle body is placed on the base so that the upper coupler is electrically connected to the lower coupler, the first terminal is electrically conductive with the upper coupler, the second terminal is connected in series with a voltage divider resistor and then grounded, the kettle lid is provided with an anti-overflow electrode and an electrode connecting piece that are electrically conductive with each other, the kettle lid is closed on the kettle body in place so that the electrode connecting piece is in contact and electrically conductive with the first terminal and the second terminal, and the output end of the voltage sampling circuit is connected in series with the lower coupler, the upper coupler, the first terminal, the electrode connecting piece, the second terminal, and the voltage divider resistor to form a detection path.

[0006] After adopting the above technical scheme, the utility model has the following advantages: by arranging the first terminal and the second terminal on the kettle lid to contact the electrode connecting piece respectively and form a detection path, that is, under normal circumstances, the first terminal and the second terminal form a series relationship rather than a parallel relationship through the electrode connecting piece, and utilize the voltage-dividing effect of the voltage-dividing resistor and the equivalent resistance R4 of the liquid in the detection path, so that the voltage values ​​collected by the AD port of the control chip are different, and the overflow prevention detection and the lid closing detection are realized at the same time. Therefore, when the product is tested at the factory, the effectiveness of the lid closing detection function and the overflow prevention function can be quickly detected in different situations, ensuring the effectiveness of the lid closing detection and the overflow prevention detection, and ensuring that users have a good user experience. Since only one AD port is used, there is no need to increase the number of electrical connection cores of the lower coupler and the upper coupler. Compared with the existing technology, the production cost of the product can be reduced on the basis of having the functions of the overflow prevention circuit and the lid closing detection.

[0007] Furthermore, the kettle body includes a heating tube, both ends of the heating tube are electrically connected to the upper coupler, the outer surface of the heating tube is grounded, and the outer surface of the heating tube is in contact with the anti-overflow electrode through the liquid in the kettle body to achieve electrical conductivity, and the equivalent resistance formed by the liquid in the kettle body is connected in parallel with the voltage divider resistor.

[0008] Furthermore, the voltage-dividing resistor is electrically connected to the outer surface of the heating tube via a wire to achieve grounding.

[0009] Furthermore, the upper coupler and the lower coupler have a grounding channel, the grounding channel of the lower coupler is grounded through a power line, and the outer surface of the heating tube is electrically connected to the grounding channel of the upper coupler through a wire to achieve grounding.

[0010] Furthermore, the upper coupler and the lower coupler have a grounding channel, the grounding channel of the lower coupler is grounded through a power line, and the voltage divider resistor is electrically connected to the grounding channel of the upper coupler through a wire to achieve grounding.

[0011] Furthermore, the voltage sampling circuit includes a pull-up resistor, a current limiting resistor and a filter capacitor. The positive potential end of the pull-up resistor is electrically connected to the VCC DC voltage, the negative potential end of the pull-up resistor is electrically connected to the lower coupler and the current limiting resistor respectively, the negative potential end of the current limiting resistor is electrically connected to the positive electrode of the filter capacitor and the AD port of the control chip respectively, the negative electrode of the filter capacitor is grounded, and the AD port of the control chip determines whether the lid of the pot is closed and the liquid is overflowing by obtaining the voltage value of the negative potential end of the pull-up resistor.

[0012] Furthermore, the kettle lid has a connecting ring extending downward, the connecting ring extends into the mouth of the top of the kettle body, the electrode connecting piece is arranged on the outer side of the connecting ring along the circumference of the connecting ring, and the first terminal and the second terminal are distributed along the circumference of the connecting ring.

[0013] By adopting the above technical solution, a relatively small-area electrode connecting piece can achieve stable contact with the first terminal and the second terminal.

[0014] Furthermore, a handle is provided on the outside of the kettle body, the top end of the handle protrudes relative to the top end of the kettle body, and a positioning notch is provided on the edge of the kettle lid, which cooperates with the top end of the handle.

[0015] With the aforementioned technical solution, when placing the kettle lid, the user needs to align the positioning notch with the top of the handle in order to put the kettle lid in place, thereby ensuring the reliability of the contact between the electrode connecting piece and the first terminal and the second terminal.

[0016] Furthermore, the kettle lid is detachably connected to the kettle body, and the kettle lid has a connecting ring extending downward, and the connecting ring is interference fit with the top end of the kettle body; or, a handle is provided on the outer side of the kettle body, and the kettle lid is hinged to the top of the handle.

[0017] The above technical solution can be adapted to different models.

[0018] Furthermore, a handle is provided on the outside of the kettle body, and a hook body is provided at the top of the handle to be hooked on the mouth of the top of the kettle body. The end of the hook body extends into the kettle body, and the first terminal and the second terminal are installed at the end of the hook body.

[0019] By adopting the above technical solution, in addition to the force of contact with the electrode connecting piece, the first terminal and the second terminal will not be subjected to other forces, thereby ensuring the structural stability during long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of a liquid heater according to the present invention (1);

[0022] Figure 2This is a schematic diagram of a liquid heater according to the present invention (II);

[0023] Figure 3 This is a schematic diagram of the pot cover in the utility model;

[0024] Figure 4 This is an equivalent circuit diagram of the detection circuit for realizing lid closing detection and overflow prevention detection in the present invention when it is in the detection path (the liquid in the kettle body contacts the overflow prevention electrode);

[0025] Figure 5 for Figure 4 The equivalent circuit diagram of the detection circuit shown when the kettle lid is not placed;

[0026] Figure 6 for Figure 4 The equivalent circuit diagram of the detection circuit shown is when the kettle lid is not properly placed and the first terminal and the second terminal are not in contact with the electrode connecting piece;

[0027] Figure 7 for Figure 4 The equivalent circuit diagram of the detection circuit shown is when the kettle lid is not properly placed and the second terminal is in contact with the electrode connecting piece, and the first terminal is not in contact with the electrode connecting piece;

[0028] Figure 8 for Figure 4 Equivalent circuit diagram of the detection circuit shown when the kettle lid is not properly placed and the second terminal is not in contact with the electrode connecting piece, and the first terminal is in contact with the electrode connecting piece (there is no liquid in the kettle body or the liquid does not contact the anti-overflow electrode);

[0029] Figure 9 for Figure 4 The equivalent circuit diagram of the detection circuit shown is when the kettle lid is not properly placed and the second terminal is not in contact with the electrode connecting piece, and the first terminal is in contact with the electrode connecting piece (the liquid in the kettle body contacts the anti-overflow electrode);

[0030] Figure 10 for Figure 4 The equivalent circuit diagram of the detection circuit shown is when the kettle lid is in place (there is no liquid in the kettle or the liquid does not contact the anti-overflow electrode). DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0032] The terms "first," "second," and so on (if any) in the specification and claims of this utility model are used to distinguish similar objects, not to describe a specific order or precedence. Even if "second" is used before a technical feature to distinguish it, it does not necessarily imply the presence of "first." It should be understood that in this utility model, "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. It should be understood that in this utility model, "plurality" refers to two or more. "And / or" is merely a description of an association between related objects, indicating that three relationships can exist. For example, "X and / or Y" can mean: X exists alone, X and Y exist simultaneously, or Y exists alone. The character " / " generally indicates that the related objects are in an "or" relationship. "Including X, Y, and Z" means that all three of X, Y, and Z are included. "Including X, Y, or Z" means that one of X, Y, and Z is included. "Including X, Y, and / or Z" means that any one, any two, or any three of X, Y, and Z are included.

[0033] The following specific embodiments are used to describe the technical solution of the present invention in detail. The following specific embodiments can be combined or replaced with each other according to actual conditions, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0034] like Figures 1 to 4 As shown, the utility model provides a liquid heater, including a base 100, a kettle body 200 and a kettle cover 300. The base 100 is provided with a control circuit board and a lower coupler 11. The control circuit board has a control chip 12 and a voltage sampling circuit 13. The sampling end of the voltage sampling circuit 13 is electrically connected to the AD port of the control chip 12; the kettle body 200 is provided with an upper coupler 21, a first terminal 22 and a second terminal 23. The kettle body 200 is placed on the base 100 so that the upper coupler 21 is electrically connected to the lower coupler 11. The first terminal 22 and the second terminal 23 are electrically connected. The terminal 22 is electrically connected to the upper coupler 21, the second terminal 23 is connected in series with the voltage-dividing resistor R3 and then grounded, the pot cover 300 is provided with an anti-overflow electrode 31 and an electrode connecting piece 32 that are electrically connected to each other, the pot cover 300 is closed on the pot body 200 in place, so that the electrode connecting piece 32 is in contact and electrically connected with the first terminal 22 and the second terminal 23, and the output end of the voltage sampling circuit 13 is connected in series with the lower coupler 11, the upper coupler 21, the first terminal 22, the electrode connecting piece 32, the second terminal 23, and the voltage-dividing resistor R3 in sequence to form a detection path.

[0035] In the present invention, the detection path can obtain an anti-overflow function by connecting the lower coupler 11, the upper coupler 21, the first terminal 22, the electrode connecting piece 32 and the anti-overflow electrode 31 in series in sequence. At the same time, the cover closing detection function can be obtained by connecting the lower coupler 11, the upper coupler 21, the first terminal 22, the electrode connecting piece 32, the second terminal 23 and the voltage divider resistor R3 in series in sequence. The realization of specific functions can be divided into the following situations.

[0036] (1) When the pot lid 300 is not placed:

[0037] The first terminal 22 and the second terminal 23 are not in contact with the electrode connecting piece 32, so the electrode connecting piece 32 fails to conduct, the detection path is broken, and the overflow prevention function fails. The voltage value detected by the AD port of the control chip 12 is the input voltage VCC of the voltage sampling circuit 13. The equivalent circuit reference Figure 5 , the detection result is that the kettle lid 300 is not closed, and the lid closing detection function is normal, and the corresponding reminder function can be used to let the user put the kettle lid 300 in place;

[0038] (2) When the pot cover 300 is not placed in place, there are three situations:

[0039] (2.1) The first terminal 22 and the second terminal 23 are not in contact with the electrode connecting piece 32, the detection path is broken, the overflow prevention function fails, and the equivalent circuit reference Figure 6 The voltage value detected by the AD port of the control chip 12 is the input voltage VCC of the voltage sampling circuit 13. The detection result is that the pot lid 300 is not closed, and the lid closing detection function is normal. The corresponding reminder function can be used to let the user put the pot lid 300 in place;

[0040] (2.2) The first terminal 22 fails to contact and conduct with the electrode connecting piece 32, and the second terminal 23 contacts and conducts with the electrode connecting piece 32. The detection path is broken, the overflow prevention function fails, and the equivalent circuit reference Figure 7 The voltage value detected by the AD port of the control chip 12 is the input voltage VCC of the voltage sampling circuit 13. The detection result is that the pot lid 300 is not closed, and the lid closing detection function is normal. The corresponding reminder function can be used to let the user put the pot lid 300 in place;

[0041] (2.3) The second terminal 23 fails to contact and conduct with the electrode connecting piece 32, but the first terminal 22 contacts and conducts with the electrode connecting piece 32. In theory, the overflow prevention function can be achieved normally.

[0042] (2.3.1) First, test the kettle body 200 when there is no liquid or the liquid does not contact the anti-overflow electrode 31. Figure 8, the voltage value detected by the AD port of the control chip 12 is the input voltage VCC of the voltage sampling circuit 13. The detection result is that the pot lid 300 is not closed, and the lid closing detection function is normal. The corresponding reminder function can be used to let the user put the pot lid 300 in place;

[0043] (2.3.2) Then the test is carried out under the condition that the liquid in the kettle body 200 contacts the anti-overflow electrode 31. The equivalent circuit is referenced Figure 9 , the voltage value detected by the AD port of the control chip 12 is the voltage V1 after being divided by the equivalent resistance R4 of the liquid. The detection result is that the liquid level is too high and the overflow prevention function is normal;

[0044] (3) When the pot lid 300 is in place:

[0045] (3.1) First, test the kettle body 200 when there is no liquid or the liquid does not contact the anti-overflow electrode 31. Figure 10 , the voltage value detected by the AD port of the control chip 12 is the voltage V2 after the voltage divider resistor R3, and the detection result is that the cover is closed normally, there is no overflow, and the cover closing detection function is normal;

[0046] (3.2) Then the test is carried out under the condition that the liquid in the kettle body 200 contacts the anti-overflow electrode 31. The equivalent circuit is referenced Figure 4 The voltage value detected by the AD port of the control chip 12 is the voltage V3 after the equivalent resistance R4 of the liquid and the voltage divider resistor R3 are connected in parallel and divided. The detection result is that the lid is closed normally, the liquid level is too high, the lid closing detection function is normal, and the anti-overflow function is normal.

[0047] In summary, the present invention sets a first terminal 22 and a second terminal 23 on the kettle lid 300, which are in contact with the electrode connecting piece 32 respectively, and forms a detection path, that is, under normal circumstances, the first terminal 22 and the second terminal 23 form a series relationship rather than a parallel relationship through the electrode connecting piece 32, and utilizes the voltage-dividing effect of the voltage-dividing resistor R3 and the equivalent resistance R4 of the liquid in the detection path, so that the voltage values ​​collected by the AD port of the control chip 12 are different, that is, the sizes of VCC, V1, V2 and V3 are all different, and overflow prevention detection and lid closing detection are realized at the same time. Therefore, when the product is tested at the factory, it is possible to quickly detect whether the lid closing detection function and the overflow prevention function are effective in different situations, ensure the effectiveness of the lid closing detection and overflow prevention detection, and ensure that users have a good user experience. Since only one AD port is used, there is no need to increase the number of electrical connection cores of the lower coupler 11 and the upper coupler 21. Compared with the existing technology, the production cost of the product is reduced on the basis of having the functions of the overflow prevention circuit and the lid closing detection.

[0048] The kettle body 200 includes a heating tube 24. Several common designs are currently available for the kettle body 200. One utilizes an integrated metal liner, with the heating tube 24 secured to the outer wall of the metal liner. Either the outer surface of the heating tube 24 or the metal liner can be grounded. Another utilizes a glass liner combined with a metal chassis, with the heating tube 24 secured to the outer bottom surface of the metal chassis. Either the outer surface of the heating tube 24 or the metal chassis can be grounded. Both ends of the heating tube 24 are electrically connected to the upper coupler 21. Regardless of the design, the outer surface of the heating tube 24 can be grounded. The outer surface of the heating tube 24 is electrically conductive to the overflow prevention electrode 31 through contact with the liquid within the kettle body 200. The equivalent resistance R4 formed by the liquid within the kettle body 200 is connected in parallel with the voltage divider resistor R3.

[0049] To reliably ground the voltage-dividing resistor R3, the voltage-dividing resistor R3 can be electrically connected to the outer surface of the heating tube 24 via a wire. Generally, the upper coupler 21 and the lower coupler 11 have grounding channels, the grounding channel of the lower coupler 11 is grounded via a power line, and the outer surface of the heating tube 24 is electrically connected to the grounding channel of the upper coupler 21 via a wire, thereby indirectly grounding the voltage-dividing resistor R3. It will be appreciated that in another embodiment, the upper coupler 21 and the lower coupler 11 have grounding channels, the grounding channel of the lower coupler 11 is grounded via a power line, and the voltage-dividing resistor R3 can be directly electrically connected to the grounding channel of the upper coupler 21 via a wire to achieve grounding.

[0050] Specifically, regarding the voltage sampling circuit 13, in one embodiment, the voltage sampling circuit 13 can be designed to include a pull-up resistor R1, a current-limiting resistor R2, and a filter capacitor C1. The positive potential end of the pull-up resistor R1 is electrically connected to the VCC DC voltage, and the negative potential end of the pull-up resistor R1 is electrically connected to the lower coupler 11 and the current-limiting resistor R2. The negative potential end of the current-limiting resistor R2 is electrically connected to the positive electrode of the filter capacitor C1 and the AD port of the control chip 12, respectively. The negative electrode of the filter capacitor C1 is grounded. The AD port of the control chip 12 determines whether the lid 300 is closed and whether the liquid has overflowed by obtaining the voltage value of the negative potential end of the pull-up resistor R1. The resistance range of the pull-up resistor R1 can be 100kΩ-1mΩ, the resistance range of the current-limiting resistor R2 can be 10Ω-10kΩ, and the capacitance range of the filter capacitor C1 can be 100pF-100nF. In addition, the resistance range of the voltage divider resistor R3 can be 1MΩ-3.3mΩ.

[0051] To calculate the values ​​of V1, V2, and V3, in one embodiment, the pull-up resistor R1 is 470kΩ, the current-limiting resistor R2 is 1kΩ, the filter capacitor C1 is 100nF, the voltage divider resistor R3 is 2.2mΩ, VCC is 5V, and the equivalent resistance R4 of the liquid in the kettle body 200 is generally between 50kΩ and 500kΩ. Here, 500kΩ is used as an example. Therefore:

[0052] (1) When the pot lid 300 is not placed: the voltage value Vin detected by the AD port of the control chip 12 is VCC=5V;

[0053] (2) When the pot cover 300 is not in place:

[0054] (2.1) Neither the first terminal 22 nor the second terminal 23 is in contact with the electrode connection piece 32: the voltage value Vin detected by the AD port of the control chip 12 is VCC = 5V;

[0055] (2.2) The first terminal 22 fails to contact and conduct with the electrode connecting piece 32, but the second terminal 23 contacts and conducts with the electrode connecting piece 32: the voltage value Vin detected by the AD port of the control chip 12 is VCC = 5V;

[0056] (2.3) The second terminal 23 fails to make contact with the electrode connecting piece 32, but the first terminal 22 makes contact with the electrode connecting piece 32.

[0057] (2.3.1) When there is no liquid in the kettle body 200 or the liquid does not contact the overflow prevention electrode 31, the voltage value detected by the AD port of the control chip 12 is Vin=VCC=5V;

[0058] (2.3.2) When the liquid in the kettle body 200 contacts the anti-overflow electrode 31, the voltage value Vin detected by the AD port of the control chip 12 is ≈2.58V, which is calculated as Vin=V1=VCC×R4 / (R1+R4)≈2.58V;

[0059] (3) When the pot lid 300 is in place:

[0060] (3.1) When there is no liquid in the kettle body 200 or the liquid does not contact the overflow prevention electrode 31, the voltage value Vin detected by the AD port of the control chip 12 is ≈4.12V, and the calculation formula is Vin=V2=VCC×R3 / (R1+R3)≈4.12V;

[0061] (3.2) When the liquid in the kettle body 200 contacts the anti-overflow electrode 31, the voltage value Vin detected by the AD port of the control chip 12 is ≈ 2.32V. The calculation formula is: First calculate the resistance value R after the equivalent resistance R4 of the liquid and the voltage divider resistor R3 are connected in parallel. 并 =(R3×R4) / (R3+R4)≈407kΩ, then calculate Vin=V3=VCC×R 并 / (R1+R 并 )≈2.32V;

[0062] In order to install the electrode connecting piece 32, the pot lid 300 can be designed to have a connecting ring 33 extending downward, which extends into the top opening of the pot body 200. The electrode connecting piece 32 is arranged on the outer side of the connecting ring 33 along the circumference of the connecting ring 33, and the first terminal 22 and the second terminal 23 are distributed along the circumference of the connecting ring 33. The size of the electrode connecting piece 32 in the circumferential direction of the connecting ring 33 is slightly larger than the spacing between the first terminal 22 and the second terminal 23. It is understandable that the first terminal 22 and the second terminal 23 can also be distributed at different heights. It is understandable that in order to increase the user's freedom when placing the pot lid 300, the electrode connecting piece 32 can be arranged along the circumference of the connecting ring 33. No matter where the pot lid 300 is placed in the circumference, the electrode connecting piece 32 can contact the first terminal 22 and the second terminal 23.

[0063] Generally, a handle 25 is provided on the outside of the kettle body 200. To guide the user in aligning the electrode connecting piece 32 with the first terminal 22 and the second terminal 23 when placing the kettle lid 300, the top of the handle 25 can be designed to protrude relative to the top end of the kettle body 200. At the same time, a positioning notch 301 is provided on the edge of the kettle lid 300, and the positioning notch 301 mates with the top of the handle 25. When placing the kettle lid 300, the user needs to align the positioning notch with the top of the handle 25 to place the kettle lid 300 in place, thereby ensuring reliable contact between the electrode connecting piece 32 and the first terminal 22 and the second terminal 23.

[0064] There are many ways to install the kettle lid 300. The present invention can be applicable to an installation method in which the kettle lid 300 is detachably connected to the kettle body 200. In order to ensure the stability of the kettle lid 300 after installation, the kettle lid 300 can have a downwardly extending connecting ring 33, and the connecting ring 33 has an interference fit with the top end of the kettle body 200. It is also applicable to an installation method in which the kettle lid 300 is hinged relative to the kettle body 200. For example, a handle 25 is provided on the outer side of the kettle body 200, and the kettle lid 300 is hinged to the top of the handle 25.

[0065] Generally, a handle 25 is provided on the outside of the kettle body 200. In one model, the top of the handle 25 is provided with a hook 251 that hooks onto the mouth of the top of the kettle body 200. The end of the hook extends into the kettle body 200. The first terminal 22 and the second terminal 23 are mounted on the end of the hook 251. Apart from the force exerted by the electrode connection piece, the first terminal 22 and the second terminal 23 are not subjected to other forces, thus ensuring the structural stability for long-term use. In another model, the top of the handle 25 can also be fixed to the outer peripheral side of the top of the kettle body 200 by a clamp, and the first terminal 22 and the second terminal 23 extend from the outside of the kettle body 200 over the mouth of the top of the kettle body 200 to the inside of the kettle body 200.

[0066] In addition to the above-mentioned preferred embodiments, the present invention has other implementation methods. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A liquid heater, comprising a base, a kettle body and a kettle cover, wherein the base is provided with a control circuit board and a lower coupler, characterized in that: The control circuit board comprises a control chip and a voltage sampling circuit, wherein a sampling end of the voltage sampling circuit is electrically connected to an AD port of the control chip; the kettle body is provided with an upper coupler, a first terminal and a second terminal, the kettle body is placed on a base so that the upper coupler is electrically connected to the lower coupler, the first terminal is electrically conductive with the upper coupler, the second terminal is connected in series with a voltage divider resistor and then to ground, the kettle lid is provided with an anti-overflow electrode and an electrode connecting piece which are electrically conductive with each other, the kettle lid is closed on the kettle body in place so that the electrode connecting piece is in contact with the first terminal and the second terminal and is electrically conductive, and the output end of the voltage sampling circuit is connected in series with the lower coupler, the upper coupler, the first terminal, the electrode connecting piece, the second terminal and the voltage divider resistor to form a detection path.

2. The liquid heater according to claim 1, wherein The kettle body includes a heating tube, both ends of the heating tube are electrically connected to the upper coupler, the outer surface of the heating tube is grounded, and the outer surface of the heating tube is in contact with the anti-overflow electrode through the liquid in the kettle body to achieve electrical conduction. The equivalent resistance formed by the liquid in the kettle body is connected in parallel with the voltage divider resistor.

3. The liquid heater according to claim 2, characterized in that The voltage dividing resistor is electrically connected to the outer surface of the heating tube via a wire to achieve grounding.

4. The liquid heater according to claim 2, characterized in that The upper coupler and the lower coupler have grounding channels. The grounding channel of the lower coupler is grounded through a power line. The outer surface of the heating tube is electrically connected to the grounding channel of the upper coupler through a wire to achieve grounding.

5. The liquid heater according to claim 1, wherein The upper coupler and the lower coupler have a grounding channel. The grounding channel of the lower coupler is grounded through a power line. The voltage divider resistor is electrically connected to the grounding channel of the upper coupler through a wire to achieve grounding.

6. The liquid heater according to claim 1, wherein The voltage sampling circuit includes a pull-up resistor, a current limiting resistor and a filter capacitor. The positive potential end of the pull-up resistor is electrically connected to the VCC DC voltage, the negative potential end of the pull-up resistor is electrically connected to the lower coupler and the current limiting resistor respectively, the negative potential end of the current limiting resistor is electrically connected to the positive electrode of the filter capacitor and the AD port of the control chip respectively, the negative electrode of the filter capacitor is grounded, and the AD port of the control chip determines whether the lid of the kettle is closed or the liquid is overflowing by obtaining the voltage value of the negative potential end of the pull-up resistor.

7. The liquid heater according to claim 1, wherein The kettle cover has a connecting ring extending downward, which extends into the mouth of the top of the kettle body. The electrode connecting piece is arranged on the outer side of the connecting ring along the circumference of the connecting ring, and the first terminal and the second terminal are distributed along the circumference of the connecting ring.

8. The liquid heater according to claim 1, wherein A handle is provided on the outside of the kettle body, the top end of the handle protrudes relative to the top end of the kettle body, and a positioning notch is provided on the edge of the kettle cover, which cooperates with the top end of the handle.

9. The liquid heater according to claim 1, wherein The kettle cover is detachably connected to the kettle body, and has a connecting ring extending downward, which is interference fit with the top end of the kettle body; or, a handle is provided on the outer side of the kettle body, and the kettle cover is hinged to the top of the handle.

10. The liquid heater according to claim 1, wherein The outer side of the kettle body is provided with a handle, the top of the handle is provided with a hook body hooked on the mouth of the top of the kettle body, the end of the hook body extends into the kettle body, and the first terminal and the second terminal are installed on the end of the hook body.

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