A portable inductive heating constant temperature cup pad circuit

Abstract

This utility model discloses a rechargeable portable induction heating constant temperature coaster circuit, including a charging interface circuit, a battery charging interface, a charging management circuit, a power switch circuit, a control circuit, an electromagnetic induction heating drive circuit, a current monitoring circuit, a power output circuit, and an induction heating coil. This utility model achieves precise temperature control through a dual-channel voltage divider design in the temperature detection circuit. When the thermistor resistance decreases to a reference threshold as the temperature rises, the control circuit turns off the electromagnetic induction heating drive circuit via a second transistor, triggering standby. After the temperature difference recovers, the heating cycle restarts, achieving a temperature control accuracy of ±1℃. The current monitoring chip provides real-time feedback of the coil current to the FB1 terminal of the induction heating drive chip, dynamically compensating for resonant frequency offset. The power output circuit uses a half-bridge NMOS chip and an LC network, increasing the driving efficiency to 85%, adapting to metal / alloy cup bodies. Combined with overcurrent protection and a low-loss capacitor layout, it achieves efficient and safe constant temperature heating.

Description

Technical Field

[0001] This utility model belongs to the field of coaster technology, specifically relating to a rechargeable portable induction heating constant temperature coaster circuit. Background Technology

[0002] With the improvement of living standards, portable constant temperature heating devices have gradually become an important need in daily life, especially for beverage keeping. Traditional heating coasters mostly use resistance wire or PTC (positive temperature coefficient) heating technology, which have problems such as low energy efficiency, uneven heating, and insufficient temperature control accuracy. In addition, they rely on continuous external power supply, making it difficult to meet the needs of mobile use.

[0003] In recent years, induction heating technology has been introduced into the field of small household appliances due to its high efficiency and safety. This technology uses the principle of electromagnetic induction to generate eddy currents at the bottom of a metal container, thus avoiding the limitations of direct contact heating. However, existing induction heating coasters still face the following technical bottlenecks:

[0004] Limited power supply: Most products rely on fixed power sources and lack built-in batteries and intelligent charging management modules, making them unusable without a power outlet and limiting their portability.

[0005] Coarse temperature control: Traditional temperature detection often uses bimetallic strips or simple thermocouples, which have high feedback delays, resulting in large temperature fluctuations (usually ±5℃ or more), making it difficult to achieve precise temperature control.

[0006] Insufficient energy efficiency and safety: The induction heating circuit design is complex, the resonant frequency stability is poor, and it is easy to cause energy loss; there is a lack of real-time current monitoring and protection mechanism, which poses a risk of overload or overheating.

[0007] Low integration: In existing solutions, modules such as charging management, power output, and control are designed separately, resulting in a large circuit size that is difficult to meet the compact requirements of portable devices.

[0008] To address the aforementioned issues, some improvement solutions attempt to introduce lithium battery power or simplify the control logic, but the following drawbacks still exist: poor coupling between the charging management circuit and the main heating circuit, resulting in low charging and discharging efficiency; the lack of closed-loop linkage between temperature feedback and power regulation, leading to slow response speed; and the fixed frequency of the electromagnetic drive signal, which cannot adapt to load changes and affects heating efficiency. Utility Model Content

[0009] In view of this, the main purpose of this utility model is to provide a rechargeable portable induction heating constant temperature coaster circuit.

[0010] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0011] Embodiment 1 of this utility model provides a rechargeable portable induction heating constant temperature coaster circuit, comprising:

[0012] The charging interface circuit is used for external power input and is connected to the charging management circuit to provide charging current.

[0013] The battery charging interface connects the battery to the charging interface circuit and is used to receive the output of the charging management circuit and charge the battery.

[0014] The charging management circuit has an input terminal connected to the charging interface circuit and an output terminal connected to the battery charging interface, and is used to control the charging status of the battery.

[0015] A power switch circuit, whose signal output terminal is connected to the signal input terminal of a control circuit, is used to control the on / off state of the circuit system.

[0016] The control circuit is used to receive user commands and sensor signals, and adjust the heating power according to preset logic.

[0017] The temperature detection circuit monitors the circuit temperature data in real time and submits the data to the control circuit. The control circuit decides whether to heat or standby based on the temperature data to achieve a constant temperature in the cup.

[0018] The electromagnetic induction heating drive circuit receives drive commands from the control circuit and generates high-frequency drive signals.

[0019] The power output circuit is connected to the output terminal of the electromagnetic induction heating drive circuit, which drives the induction heating coil to generate an alternating magnetic field.

[0020] An induction heating coil forms a resonant circuit with the power output circuit to induction heat the water cup.

[0021] The current monitoring circuit collects the operating current data of the induction heating coil in real time and feeds the data back to the electromagnetic induction heating drive circuit.

[0022] In the above scheme, the charging interface circuit includes a TEPY-C interface, a 21st resistor, and a 23rd resistor. The third terminal of the TEPY-C interface is connected in series with the 21st resistor and then connected to the first terminal of the TEPY-C interface, the first terminal of the 23rd resistor, and the sixth terminal of the TEPY-C interface, respectively, and then grounded. The second terminal of the 23rd resistor is connected to the fourth terminal of the TEPY-C interface.

[0023] In the above scheme, the charging management circuit includes a charging management chip, a first resistor, a second resistor, a third resistor, an eighth resistor, a second capacitor, an eighth capacitor, a tenth capacitor, a twelfth capacitor, a first light-emitting diode (LED), and a first boost inductor. The first terminal of the first boost inductor is connected to the second terminal of the TEPY-C interface, the fifth terminal of the TEPY-C interface, the first terminal of the third resistor, and the first terminal of the twelfth capacitor. The second terminal of the first boost inductor is connected to the first terminal of the eighth capacitor and the LX terminal of the charging management chip. The second terminal of the eighth capacitor is connected to the BST terminal of the charging management chip. The second terminal of the third resistor is connected to the VI terminal of the charging management chip. The N terminal is connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the second terminal of the twelfth capacitor, the negative terminal of the first light-emitting diode, the first terminal of the second capacitor, the second terminal of the first resistor, and the second terminal of the second resistor, and then grounded. The positive terminal of the first light-emitting diode is connected to the LED terminal of the charging management chip in series with the eighth resistor. The second terminal of the second capacitor is connected to the VSYS terminal of the charging management chip. The second terminal of the second resistor is connected to the NTC terminal of the charging management chip. The second terminal of the first resistor is connected to the VSET terminal of the charging management chip. The VOUT terminal of the charging management chip is connected to the first terminal of the battery charging interface. The second terminal of the battery charging interface is connected to the battery.

[0024] In the above scheme, the power switch circuit includes a power switch chip, a switch, and a third capacitor. The VDD terminal of the power switch chip is connected to the NF terminal, the RC terminal, and the VOUT terminal of the charging management chip, respectively. The VSS terminal of the power switch chip is connected to the NFHL terminal, the first terminal of the third capacitor, and the first terminal of the switch, respectively, and then grounded. The second terminal of the third capacitor is connected to the second terminal of the switch and the ONOFF terminal of the power switch chip, respectively.

[0025] In the above scheme, the control circuit includes a control chip, a 22nd resistor, a 20th resistor, an 18th resistor, a 19th resistor, a 4th resistor, a 9th resistor, a 5th resistor, a 6th resistor, a 7th resistor, a first transistor, a second transistor, a first diode, an 11th capacitor, and a third light-emitting diode. The first terminal of the 22nd resistor is connected to the OUT terminal of the power switch chip, the first terminal of the 11th capacitor, the first terminal of the 20th resistor, the first terminal of the 4th resistor, the first terminal of the 5th resistor, the first terminal of the 7th resistor, and the VDD terminal of the control chip. The second terminal of the 22nd resistor is connected in series with the third light-emitting diode and then connected to the second terminal of the 11th capacitor and the second transistor. The emitter, drain of the first transistor, first terminal of the sixth resistor, and VSS terminal of the control chip are connected. The collector of the second transistor is connected to the second terminal of the twentieth resistor. The base of the second transistor is connected to the cathode of the first diode, first terminal of the eighteenth resistor, first terminal of the nineteenth resistor, and first terminal of the ninth resistor. The anode of the first diode is connected to the second terminal of the fourth resistor and the source of the first transistor. The gate of the first transistor is connected to the second terminal of the fifth resistor, first terminal of the seventh resistor, and second terminal of the sixth resistor. The second terminal of the eighteenth resistor is connected to the OUT2 terminal of the control chip. The second terminal of the nineteenth resistor is connected to the OUT1 terminal of the control chip.

[0026] In the above scheme, the temperature detection circuit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a first thermistor, and a second thermistor. The first end of the sixteenth resistor is connected to the first end of the fifteenth resistor, the first end of the seventeenth resistor, and the VDD terminal of the control chip. The second end of the sixteenth resistor is connected to the first end of the first thermistor and the IN2- terminal of the control chip. The second end of the fifteenth resistor is connected to the IN2+ terminal of the control chip, the second end of the fourteenth resistor, the second end of the ninth resistor, and the IN1+ terminal of the control chip. The second end of the first thermistor is connected to the second end of the fourteenth resistor and the first end of the second thermistor. The second end of the second thermistor is connected to the second end of the seventeenth resistor and the IN1- terminal of the control chip.

[0027] In the above scheme, the electromagnetic induction heating drive circuit includes an induction heating drive chip, an eleventh resistor, a twenty-fifth resistor, and a second light-emitting diode. The VDD terminal of the induction heating drive chip is connected to the OUT terminal of the power switch chip. The FB2 terminal of the induction heating drive chip is connected to the collector of the second transistor. The R1 terminal of the induction heating drive chip is connected in series with the eleventh resistor and then connected to the R2 terminal of the induction heating drive chip. The LED terminal of the induction heating drive chip is connected in series with the twenty-fifth resistor and then connected to the second terminal of the seventh resistor and the positive terminal of the second light-emitting diode. The negative terminal of the second light-emitting diode is connected to the GND terminal of the induction heating drive chip.

[0028] In the above scheme, the current monitoring circuit includes a current monitoring chip, a fourth diode, a thirteenth resistor, a twenty-fourth resistor, a fourth capacitor, and a twelfth resistor. The IN1 terminal of the current monitoring chip is connected to the OUT terminal of the induction heating drive chip. The OUT1 terminal of the current monitoring chip is connected in series with the twelfth resistor and then connected to the GND1 terminal of the current monitoring chip. The GND2 terminal of the current monitoring chip is connected in series with the fourth diode and the thirteenth resistor and then connected to the first terminal of the twenty-fourth resistor, the first terminal of the fourth capacitor, and the FB1 terminal of the induction heating drive chip, respectively. The second terminal of the fourth capacitor is connected to the second terminal of the twenty-fourth resistor and the negative terminal of the second light-emitting diode and then grounded.

[0029] In the above scheme, the power output circuit includes a first NMOS chip, a second NMOS chip, a first capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and a ninth capacitor. The OUT terminal of the first NMOS chip is connected to the OUT2 terminal of the current monitoring chip, the SAM terminal of the first NMOS chip, the OUT terminal of the second NMOS chip, the SAM terminal of the second NMOS chip, the first terminal of the sixth capacitor, the first terminal of the seventh capacitor, and the first terminal of the ninth capacitor. The GND terminal of the first NMOS chip is connected to the GND terminal of the second NMOS chip. The second terminal of the ninth capacitor is connected to the second terminal of the sixth capacitor, the second terminal of the seventh capacitor, the first terminal of the battery charging interface, the first terminal of the first capacitor, and the first terminal of the fifth capacitor. The second terminal of the first capacitor is connected to the second terminal of the fifth capacitor and then grounded.

[0030] In the above scheme, the first end of the induction heating coil is connected to the second end of the ninth capacitor, and the second end of the induction heating coil is connected to the first end of the ninth capacitor.

[0031] Compared with existing technologies, this invention achieves precise temperature control through a dual-channel voltage divider design in the temperature detection circuit. When the resistance of the thermistor decreases to the reference threshold as the temperature rises, the control circuit turns off the electromagnetic induction heating drive circuit through the second transistor, triggering standby. After the temperature difference recovers, the heating cycle restarts, achieving a temperature control accuracy of ±1℃. The current monitoring chip provides real-time feedback of the coil current to the FB1 terminal of the induction heating drive chip, dynamically compensating for the resonant frequency offset. The power output circuit uses a half-bridge NMOS chip and an LC network, increasing the driving efficiency to 85%, adapting to metal / alloy cup bodies. Combined with overcurrent protection and a low-loss capacitor layout, it achieves efficient and safe constant temperature heating. Attached Figure Description

[0032] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this invention, illustrate exemplary embodiments of the present invention and, together with their description, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic block diagram of the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the charging interface circuit in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model;

[0035] Figure 3 This is a schematic diagram of the battery charging interface in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model.

[0036] Figure 4 This is a schematic diagram of the charging management circuit in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model;

[0037] Figure 5 This is a schematic diagram of the power switch circuit in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model;

[0038] Figure 6 This is a schematic diagram of the control circuit and temperature detection circuit in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model.

[0039] Figure 7 This is a schematic diagram of the electromagnetic induction heating drive circuit, current monitoring circuit, and power output circuit in the rechargeable portable induction heating constant temperature coaster circuit described in this embodiment of the utility model. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0041] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0043] This utility model embodiment provides a rechargeable portable induction heating constant temperature coaster circuit, such as... Figure 1-6 As shown, it includes:

[0044] The charging interface circuit is used for external power input and is connected to the charging management circuit to provide charging current.

[0045] The battery charging interface connects the battery to the charging interface circuit and is used to receive the output of the charging management circuit and charge the battery.

[0046] The charging management circuit has an input terminal connected to the charging interface circuit and an output terminal connected to the battery charging interface, and is used to control the charging status of the battery.

[0047] A power switch circuit, whose signal output terminal is connected to the signal input terminal of a control circuit, is used to control the on / off state of the circuit system.

[0048] The control circuit is used to receive user commands and sensor signals, and adjust the heating power according to preset logic.

[0049] The temperature detection circuit monitors the circuit temperature data in real time and submits the data to the control circuit. The control circuit decides whether to heat or standby based on the temperature data to achieve a constant temperature in the cup.

[0050] The electromagnetic induction heating drive circuit receives drive commands from the control circuit and generates high-frequency drive signals.

[0051] The power output circuit is connected to the output terminal of the electromagnetic induction heating drive circuit, which drives the induction heating coil to generate an alternating magnetic field.

[0052] An induction heating coil forms a resonant circuit with the power output circuit to induction heat the water cup.

[0053] The current monitoring circuit collects the operating current data of the induction heating coil in real time and feeds the data back to the electromagnetic induction heating drive circuit.

[0054] like Figure 1 and Figure 2 As shown, the charging interface circuit includes a TEPY-C interface USB1, a 21st resistor R21, and a 23rd resistor R23. The third terminal of the TEPY-C interface USB1 is connected in series with the 21st resistor R21 and then connected to the first terminal of the TEPY-C interface USB1, the first terminal of the 23rd resistor R23, and the sixth terminal of the TEPY-C interface USB1, and then grounded. The second terminal of the 23rd resistor R23 is connected to the fourth terminal of the TEPY-C interface USB1.

[0055] like Figures 1-4As shown, the charging management circuit includes a charging management chip IC1, a first resistor R1, a second resistor R2, a third resistor R3, an eighth resistor R8, a second capacitor C2, an eighth capacitor C8, a tenth capacitor C10, a twelfth capacitor C12, a first light-emitting diode LED1, and a first boost inductor L1. The first terminal of the first boost inductor L1 is connected to the second terminal and the fifth terminal of the TEPY-C interface USB1, the first terminal of the third resistor R3, and the first terminal of the twelfth capacitor C12. The second terminal of the first boost inductor L1 is connected to the first terminal of the eighth capacitor C8 and the LX terminal of the charging management chip IC1. The second terminal of the eighth capacitor C8 is connected to the BST terminal of the charging management chip IC1. The second terminal of the third resistor R3 is connected to the VIN terminal and the… The first end of the tenth capacitor C10 is connected to the ground. The second end of the tenth capacitor C10 is connected to the second end of the twelfth capacitor C12, the negative terminal of the first light-emitting diode LED1, the first end of the second capacitor C2, the second end of the first resistor R1, and the second end of the second resistor R2. The positive terminal of the first light-emitting diode LED1 is connected to the LED terminal of the charging management chip IC1 in series with the eighth resistor R8. The second end of the second capacitor C2 is connected to the VSYS terminal of the charging management chip IC1. The second end of the second resistor R2 is connected to the NTC terminal of the charging management chip IC1. The second end of the first resistor R1 is connected to the VSET terminal of the charging management chip IC1. The VOUT terminal of the charging management chip IC1 is connected to the first end of the battery charging interface XH. The second end of the battery charging interface XH is connected to the battery.

[0056] like Figure 1 , Figure 4 and Figure 5 As shown, the power switch circuit includes a power switch chip IC3, a switch BS1, and a third capacitor C3. The VDD terminal of the power switch chip IC3 is connected to the NF terminal, the RC terminal, and the VOUT terminal of the charging management chip IC1, respectively. The VSS terminal of the power switch chip IC3 is connected to the NFHL terminal, the first terminal of the third capacitor C3, and the first terminal of the switch BS1, and then grounded. The second terminal of the third capacitor C3 is connected to the second terminal of the switch BS1 and the ONOFF terminal of the power switch chip IC3, respectively.

[0057] like Figure 5 and Figure 6As shown, the control circuit includes a control chip IC5, a 22nd resistor R22, a 20th resistor R20, an 18th resistor R18, a 19th resistor R19, a 4th resistor R4, a 9th resistor R9, a 5th resistor R5, a 6th resistor R6, a 7th resistor R7, a 1st transistor M1, a 2nd transistor Q2, a 1st diode D1, an 11th capacitor C11, and a 3rd light-emitting diode LED3. The first terminal of the 22nd resistor R22 is connected to the OUT terminal of the power switch chip IC3, the first terminal of the 11th capacitor C11, the first terminal of the 20th resistor R20, the first terminal of the 4th resistor R4, the first terminal of the 5th resistor R5, the first terminal of the 7th resistor R7, and the VDD terminal of the control chip IC5. The second terminal of the 22nd resistor R22 is connected in series with the 3rd light-emitting diode LED3 and then connected to the second terminal of the 11th capacitor C11, the emitter of the 2nd transistor Q2, the drain of the 1st transistor M1, the first terminal of the 6th resistor R6, and the control chip IC5. The VSS terminal of C5 is connected, the collector of the second transistor Q2 is connected to the second terminal of the twentieth resistor R20, the base of the second transistor Q2 is connected to the cathode of the first diode D1, the first terminal of the eighteenth resistor R18, the first terminal of the nineteenth resistor R19, and the first terminal of the ninth resistor R9, respectively, the anode of the first diode D1 is connected to the second terminal of the fourth resistor R4 and the source of the first transistor M1, the gate of the first transistor M1 is connected to the second terminal of the fifth resistor R5, the first terminal of the seventh resistor R7, and the second terminal of the sixth resistor R6, respectively, the second terminal of the eighteenth resistor R18 is connected to the OUT2 terminal of the control chip IC5, and the second terminal of the nineteenth resistor R19 is connected to the OUT1 terminal of the control chip IC5.

[0058] like Figure 5 and Figure 6As shown, the temperature detection circuit includes a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a first thermistor RT1, and a second thermistor RT2. The first end of the sixteenth resistor R16 is connected to the first ends of the fifteenth resistor R15, the seventeenth resistor R17, and the VDD terminal of the control chip IC5. The second end of the sixteenth resistor R16 is connected to the first end of the first thermistor RT1 and the IN2- terminal of the control chip IC5. The second end of the fifteenth resistor R15 is connected to the IN2+ terminal of the control chip IC5, the second end of the fourteenth resistor R14, the second end of the ninth resistor R9, and the IN1+ terminal of the control chip IC5. The second end of the first thermistor RT1 is connected to the second end of the fourteenth resistor R14 and the first end of the second thermistor RT2. The second end of the second thermistor RT2 is connected to the second end of the seventeenth resistor R17 and the IN1- terminal of the control chip IC5.

[0059] like Figure 5 , Figure 6 and Figure 7 As shown, the electromagnetic induction heating drive circuit includes an induction heating drive chip IC, an eleventh resistor R11, a twenty-fifth resistor R25, and a second light-emitting diode LED2. The VDD terminal of the induction heating drive chip IC is connected to the OUT terminal of the power switch chip IC3. The FB2 terminal of the induction heating drive chip IC is connected to the collector of the second transistor Q2. The R1 terminal of the induction heating drive chip IC is connected in series with the eleventh resistor R11 and then connected to the R2 terminal of the induction heating drive chip IC. The LED terminal of the induction heating drive chip IC is connected in series with the twenty-fifth resistor R25 and then connected to the second terminal of the seventh resistor R7 and the positive terminal of the second light-emitting diode LED2. The negative terminal of the second light-emitting diode LED2 is connected to the GND terminal of the induction heating drive chip IC.

[0060] like Figure 7As shown, the current monitoring circuit includes a current monitoring chip IC7, a fourth diode D4, a thirteenth resistor R13, a twenty-fourth resistor R24, a fourth capacitor C4, and a twelfth resistor R12. The IN1 terminal of the current monitoring chip IC7 is connected to the OUT terminal of the induction heating drive chip IC. The OUT1 terminal of the current monitoring chip IC7 is connected in series with the twelfth resistor R12 and then connected to the GND1 terminal of the current monitoring chip IC7. The GND2 terminal of the current monitoring chip IC7 is connected in series with the fourth diode D4 and the thirteenth resistor R13 and then connected to the first terminal of the twenty-fourth resistor R24, the first terminal of the fourth capacitor C4, and the FB1 terminal of the induction heating drive chip IC, respectively. The second terminal of the fourth capacitor C4 is connected to the second terminal of the twenty-fourth resistor R24 ​​and the negative terminal of the second light-emitting diode LED2 and then grounded.

[0061] like Figure 7 As shown, the power output circuit includes a first NMOS chip IC4, a second NMOS chip IC6, a first capacitor C1, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and a ninth capacitor C9. The OUT terminal of the first NMOS chip IC4 is connected to the OUT2 terminal of the current monitoring chip IC7, the SAM terminal of the first NMOS chip IC4, the OUT terminal of the second NMOS chip IC6, the SAM terminal of the second NMOS chip IC6, the first terminal of the sixth capacitor C6, the first terminal of the seventh capacitor C7, and the first terminal of the ninth capacitor C9. The GND terminal of the first NMOS chip IC4 is connected to the GND terminal of the second NMOS chip IC6. The second terminal of the ninth capacitor C9 is connected to the second terminal of the sixth capacitor C6, the second terminal of the seventh capacitor C7, the first terminal of the battery charging interface XH, the first terminal of the first capacitor C1, and the first terminal of the fifth capacitor C5. The second terminal of the first capacitor C1 is connected to the second terminal of the fifth capacitor C5 and then grounded.

[0062] In the above scheme, the first end OTP1 of the induction heating coil is connected to the second end of the ninth capacitor C9, and the second end OTP2 of the induction heating coil is connected to the first end of the ninth capacitor C9.

[0063] like Figure 1-6 As shown, this thermostatic coaster circuit achieves intelligent heating and precise temperature control through the collaborative operation of multiple modules. Its working principle is as follows:

[0064] Power supply and charging management: External power is input via the Type-C interface USB1, and controlled by the charging management chip IC1, the built-in battery is charged in three stages: constant current, constant voltage, and trickle charging. During charging, the NTC terminal of the charging management chip IC1 monitors the battery temperature through the second resistor R2, and triggers protection if an abnormality is detected; the first light-emitting diode LED1 displays the charging status (red light for charging / green light for full charge) through the eighth resistor R8.

[0065] Temperature detection and logic control: The reference voltage is generated by voltage division of the fourteenth resistor R14 and the fifteenth resistor R15 to produce a fixed reference voltage, which is input to the IN1+ terminal of the control chip IC5.

[0066] Dual-channel temperature sampling: The working surface temperature is detected by voltage division between the seventeenth resistor R17 and the second thermistor RT2 (negative temperature coefficient), and the voltage signal is input to the IN1- terminal of the control chip IC5.

[0067] For PCB temperature detection, the sixteenth resistor R16 and the first thermistor RT1 form a voltage divider, and the signal is input to the IN2 terminal.

[0068] Temperature comparison and decision: When the temperature rises and causes the resistance of the first thermistor RT1 or the second thermistor RT2 to drop, and its voltage divider is lower than the reference voltage, the control chip IC5 outputs a low level through the OUT1 / OUT2 terminal, driving the second transistor Q2 to turn off, thereby shutting down the electromagnetic induction heating drive circuit and stopping heating; when the temperature drops back below the threshold, the control chip re-enables the drive signal and starts the heating cycle.

[0069] Electromagnetic induction heating and power output

[0070] Drive signal generation: The induction heating drive chip IC receives the PWM command from the control chip IC5 and generates a high-frequency square wave signal (20-50kHz). The dead time is adjusted by the eleventh resistor R11 to prevent the half-bridge NMOS transistors (first NMOS chip IC4 and second NMOS chip IC6) from shooting through.

[0071] Resonance and magnetic field generation: In the power output circuit, the first NMOS chip IC4 and the second NMOS chip IC6 are alternately turned on, forming an LC resonant circuit with the ninth capacitor C9 and the induction heating coil. The coil generates a high-frequency alternating magnetic field, causing eddy currents to heat up the bottom of the metal cup.

[0072] Current monitoring and dynamic compensation

[0073] The current monitoring chip IC7 samples the coil current through the fourth diode D4. After voltage division by the thirteenth resistor R13 and the twenty-fourth resistor R24, the current is fed back to the FB1 terminal of the induction heating driver chip IC. When the load changes and causes the resonant frequency to shift, the voltage change at the FB1 terminal triggers the induction heating driver chip IC to adjust the output frequency, maintain the LC resonant state, and ensure stable energy transfer efficiency (above 85%).

[0074] Overcurrent protection: The current monitoring circuit detects the current in real time. If the current exceeds the set threshold, the drive signal is immediately shut off by adjusting the twelfth resistor R12 and the twenty-fourth resistor R24.

[0075] Overheat protection: If the PCB temperature (NTC1) or the working surface temperature (NTC2) exceeds the limit (e.g., >60℃), the control chip IC5 will be forced to enter standby mode.

[0076] Reverse voltage protection: The fourth diode (D4) suppresses the reverse voltage spike when the first NMOS chip IC4 and the second NMOS chip IC6 are turned off, thus protecting the power devices.

[0077] The workflow is closed-loop: temperature detection, control decision, drive adjustment, magnetic field heating, current feedback, frequency compensation, and temperature re-detection form a closed-loop control, ultimately achieving constant temperature (±1℃) and efficient energy conversion in the water cup.

[0078] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A chargeable portable inductive heating constant temperature cup mat circuit, characterized in that, include: The charging interface circuit is used for external power input and is connected to the charging management circuit to provide charging current. The battery charging interface connects the battery to the charging interface circuit and is used to receive the output of the charging management circuit and charge the battery. The charging management circuit has an input terminal connected to the charging interface circuit and an output terminal connected to the battery charging interface, and is used to control the charging status of the battery. A power switch circuit, whose signal output terminal is connected to the signal input terminal of a control circuit, is used to control the on / off state of the circuit system. The control circuit is used to receive user commands and sensor signals, and adjust the heating power according to preset logic. The temperature detection circuit monitors the circuit temperature data in real time and submits the data to the control circuit. The control circuit decides whether to heat or standby based on the temperature data to achieve a constant temperature in the cup. The electromagnetic induction heating drive circuit receives drive commands from the control circuit and generates high-frequency drive signals. The power output circuit is connected to the output terminal of the electromagnetic induction heating drive circuit, which drives the induction heating coil to generate an alternating magnetic field. An induction heating coil forms a resonant circuit with the power output circuit to induction heat the water cup. The current monitoring circuit collects the operating current data of the induction heating coil in real time and feeds the data back to the electromagnetic induction heating drive circuit.

2. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 1, characterized in that, The charging interface circuit includes a TEPY-C interface, a 21st resistor, and a 23rd resistor. The third terminal of the TEPY-C interface is connected in series with the 21st resistor and then connected to the first terminal of the TEPY-C interface, the first terminal of the 23rd resistor, and the sixth terminal of the TEPY-C interface, respectively, and then grounded. The second terminal of the 23rd resistor is connected to the fourth terminal of the TEPY-C interface.

3. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 2, characterized in that, The charging management circuit includes a charging management chip, a first resistor, a second resistor, a third resistor, an eighth resistor, a second capacitor, an eighth capacitor, a tenth capacitor, a twelfth capacitor, a first light-emitting diode (LED), and a first boost inductor. The first terminal of the first boost inductor is connected to the second terminal and the fifth terminal of the TEPY-C interface, the first terminal of the third resistor, and the first terminal of the twelfth capacitor. The second terminal of the first boost inductor is connected to the first terminal of the eighth capacitor and the LX terminal of the charging management chip. The second terminal of the eighth capacitor is connected to the BST terminal of the charging management chip. The second terminal of the third resistor is connected to the VIN terminal of the charging management chip and the twelfth capacitor. The first terminal is connected, and the second terminal of the tenth capacitor is connected to the second terminal of the twelfth capacitor, the negative terminal of the first light-emitting diode, the first terminal of the second capacitor, the second terminal of the first resistor, and the second terminal of the second resistor, and then grounded. The positive terminal of the first light-emitting diode is connected to the LED terminal of the charging management chip in series with the eighth resistor. The second terminal of the second capacitor is connected to the VSYS terminal of the charging management chip. The second terminal of the second resistor is connected to the NTC terminal of the charging management chip. The second terminal of the first resistor is connected to the VSET terminal of the charging management chip. The VOUT terminal of the charging management chip is connected to the first terminal of the battery charging interface. The second terminal of the battery charging interface is connected to the battery.

4. The rechargeable portable induction heating constant temperature coaster circuit according to claim 3, characterized in that, The power switch circuit includes a power switch chip, a switch, and a third capacitor. The VDD terminal of the power switch chip is connected to the NF terminal, the RC terminal, and the VOUT terminal of the charging management chip, respectively. The VSS terminal of the power switch chip is connected to the NFHL terminal, the first terminal of the third capacitor, and the first terminal of the switch, respectively, and then grounded. The second terminal of the third capacitor is connected to the second terminal of the switch and the ONOFF terminal of the power switch chip, respectively.

5. The rechargeable portable induction heating constant temperature coaster circuit according to claim 4, characterized in that, The control circuit includes a control chip, a 22nd resistor, a 20th resistor, an 18th resistor, a 19th resistor, a 4th resistor, a 9th resistor, a 5th resistor, a 6th resistor, a 7th resistor, a first transistor, a second transistor, a first diode, an 11th capacitor, and a third light-emitting diode. The first terminal of the 22nd resistor is connected to the OUT terminal of the power switch chip, the first terminal of the 11th capacitor, the first terminal of the 20th resistor, the first terminal of the 4th resistor, the first terminal of the 5th resistor, the first terminal of the 7th resistor, and the VDD terminal of the control chip. The second terminal of the 22nd resistor is connected in series with the third light-emitting diode and then connected to the second terminal of the 11th capacitor and the emitter of the second transistor. The drain of the first transistor, the first terminal of the sixth resistor, and the VSS terminal of the control chip are connected. The collector of the second transistor is connected to the second terminal of the twentieth resistor. The base of the second transistor is connected to the cathode of the first diode, the first terminal of the eighteenth resistor, the first terminal of the nineteenth resistor, and the first terminal of the ninth resistor. The anode of the first diode is connected to the second terminal of the fourth resistor and the source of the first transistor. The gate of the first transistor is connected to the second terminal of the fifth resistor, the first terminal of the seventh resistor, and the second terminal of the sixth resistor. The second terminal of the eighteenth resistor is connected to the OUT2 terminal of the control chip, and the second terminal of the nineteenth resistor is connected to the OUT1 terminal of the control chip.

6. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 5, characterized in that, The temperature detection circuit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a first thermistor, and a second thermistor. The first end of the sixteenth resistor is connected to the first ends of the fifteenth resistor, the seventeenth resistor, and the VDD terminal of the control chip. The second end of the sixteenth resistor is connected to the first end of the first thermistor and the IN2- terminal of the control chip. The second end of the fifteenth resistor is connected to the IN2+ terminal of the control chip, the second end of the fourteenth resistor, the second end of the ninth resistor, and the IN1+ terminal of the control chip. The second end of the first thermistor is connected to the second end of the fourteenth resistor and the first end of the second thermistor. The second end of the second thermistor is connected to the second end of the seventeenth resistor and the IN1- terminal of the control chip.

7. The rechargeable portable induction heating constant temperature coaster circuit according to claim 6, characterized in that, The electromagnetic induction heating drive circuit includes an induction heating drive chip, an eleventh resistor, a twenty-fifth resistor, and a second light-emitting diode. The VDD terminal of the induction heating drive chip is connected to the OUT terminal of the power switch chip. The FB2 terminal of the induction heating drive chip is connected to the collector of the second transistor. The R1 terminal of the induction heating drive chip is connected in series with the eleventh resistor and then connected to the R2 terminal of the induction heating drive chip. The LED terminal of the induction heating drive chip is connected in series with the twenty-fifth resistor and then connected to the second terminal of the seventh resistor and the positive terminal of the second light-emitting diode. The negative terminal of the second light-emitting diode is connected to the GND terminal of the induction heating drive chip.

8. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 7, characterized in that, The current monitoring circuit includes a current monitoring chip, a fourth diode, a thirteenth resistor, a twenty-fourth resistor, a fourth capacitor, and a twelfth resistor. The IN1 terminal of the current monitoring chip is connected to the OUT terminal of the induction heating drive chip. The OUT1 terminal of the current monitoring chip is connected in series with the twelfth resistor and then connected to the GND1 terminal of the current monitoring chip. The GND2 terminal of the current monitoring chip is connected in series with the fourth diode and the thirteenth resistor and then connected to the first terminal of the twenty-fourth resistor, the first terminal of the fourth capacitor, and the FB1 terminal of the induction heating drive chip, respectively. The second terminal of the fourth capacitor is connected to the second terminal of the twenty-fourth resistor and the negative terminal of the second light-emitting diode and then grounded.

9. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 8, characterized in that, The power output circuit includes a first NMOS chip, a second NMOS chip, a first capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and a ninth capacitor. The OUT terminal of the first NMOS chip is connected to the OUT2 terminal of the current monitoring chip, the SAM terminal of the first NMOS chip, the OUT terminal of the second NMOS chip, the SAM terminal of the second NMOS chip, the first terminal of the sixth capacitor, the first terminal of the seventh capacitor, and the first terminal of the ninth capacitor. The GND terminal of the first NMOS chip is connected to the GND terminal of the second NMOS chip. The second terminal of the ninth capacitor is connected to the second terminal of the sixth capacitor, the second terminal of the seventh capacitor, the first terminal of the battery charging interface, the first terminal of the first capacitor, and the first terminal of the fifth capacitor. The second terminal of the first capacitor is connected to the second terminal of the fifth capacitor and then grounded.

10. The electrically chargeable portable inductive heating constant temperature cup mat circuit according to claim 9, characterized in that, The first end of the induction heating coil is connected to the second end of the ninth capacitor, and the second end of the induction heating coil is connected to the first end of the ninth capacitor.

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