Electromagnetic heating circuit of heating smoking set, control method of electromagnetic heating circuit and heating smoking set

Abstract

The invention discloses an electromagnetic heating circuit of a heating smoking set, a control method of the electromagnetic heating circuit and the heating smoking set. The circuit comprises a battery cell, a boosting module, an LC resonance module and a control module. The boost module comprises a first capacitor, a boost inductor, a first switch, a first pulse width modulation unit and a diode. The first pulse width modulation unit generates a first control signal. The LC resonance module comprises a second capacitor, a second switch, a third switch, a second pulse width modulation unit, a third pulse width modulation unit and an LC circuit; the second pulse width modulation unit and the third pulse width modulation unit respectively generate a second control signal and a third control signal which have the same frequency and opposite phases; the control module adjusts the duty ratio of the first control signal and the frequencies and duty ratios of the second control signal and the third control signal so as to adjust the heating power of the LC circuit. The problem that noise is generated when the heating circuit switches on and off the LC circuit is solved, and meanwhile, the temperature curve change can be quickly responded by dynamically adjusting the boost voltage.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of heat exchangers, and in particular to an electromagnetic heating circuit for heating a smoking device, a control method thereof, and a heating smoking device. Background Art

[0002] The electromagnetic heating circuits in current heated smoking products generally use a boost circuit and an LC circuit to jointly complete the heating of the heating element. In the preheating stage, the boost is started to increase the output power to allow the heating element to heat up quickly. In the insulation stage, the boost is turned off and the battery cell directly drives the LC circuit to heat. When the real-time temperature is lower than the target temperature, the LC circuit output is turned on. When the real-time temperature is higher than the target temperature, the LC circuit output is turned off.

[0003] During the temperature control process, the LC circuit needs to be frequently switched on and off. Since the output current will change suddenly, noise is likely to be generated. Moreover, the switching can easily cause ripples in the boost circuit, which is not conducive to temperature control. During the insulation stage, the battery cell directly drives the heating circuit. When the temperature needs to be increased, the purpose of rapid temperature increase cannot be achieved when the battery cell voltage is low.

[0004] Therefore, existing electromagnetic heating circuits still have problems such as slow heating and difficulty in controlling temperature. Summary of the Invention

[0005] In the first aspect, the present application provides an electromagnetic heating circuit for a heated smoking device, a control method thereof, and a heated smoking device. The present invention solves the problem of noise generated by the heating circuit in the case of a switching LC circuit; combined with dynamic adjustment of the boost voltage, it can quickly respond to changes in the temperature curve.

[0006] In a first aspect, the present application proposes an electromagnetic heating circuit for heating a smoking device, comprising:

[0007] Battery cells, used to provide electrical energy;

[0008] Boost module, including:

[0009] a first capacitor, a first end of which is connected to the positive electrode of the battery cell, and a second end of which is connected to the negative electrode of the battery cell;

[0010] a boost inductor, a first end of which is connected to the positive electrode of the battery cell, and a second end of which is connected to the input end of the diode and the first electrode of the first switch; a first pulse width modulation unit, connected to the control end of the first switch, for generating a first control signal;

[0011] LC resonance module, including:

[0012] a second capacitor, a first end of which is connected to the output end of the diode and the first electrode of the second switch; a second electrode of the second switch is connected to the first electrode of the third switch and the first end of the LC circuit; and a negative electrode of the battery cell is further connected to the second electrode of the first switch, the second end of the second capacitor, the second electrode of the third switch, and the second end of the LC circuit;

[0013] a second pulse width modulation unit, connected to the control terminal of the second switch, and configured to generate a second control signal;

[0014] a third pulse width modulation unit, connected to the control terminal of the third switch, and configured to generate a third control signal;

[0015] Wherein, the second control signal and the third control signal have the same frequency and opposite phase;

[0016] Control module, configured as:

[0017] adjusting the duty cycle of the first control signal to adjust the amplitude of the boost voltage;

[0018] The frequencies of the second control signal and the third control signal are adjusted to make the LC circuit operate in a resonant state, and the duty ratios of the two are controlled within a preset control range to adjust the heating power of the LC circuit.

[0019] As a preferred solution, the LC circuit includes a heating module and an oscillating capacitor connected in series, and the heating module includes a heating inductor and a heating tube.

[0020] As a preferred solution, the first switch, the second switch and the third switch include switch MOS tubes;

[0021] When the battery is turned on, the battery cell output is controlled; when the battery is turned off, the battery cell is controlled to be cut off.

[0022] As a preferred solution, it also includes:

[0023] a temperature detection module, electrically connected to the control module, for detecting the real-time temperature of the heating module in the LC circuit;

[0024] The control module is further configured to dynamically adjust the stepping of the duty cycles of the second control signal and the third control signal according to the temperature difference between the real-time temperature and the target temperature.

[0025] As a preferred solution, it also includes:

[0026] a voltage detection module, connected to the output ends of the control module and the diode, respectively, for detecting the boost voltage of the boost module;

[0027] The control module is further configured to dynamically adjust the duty cycle of the first control signal according to a difference between the boost voltage and the target voltage, so as to automatically compensate for the amplitude of the boost voltage.

[0028] In a second aspect, the present application further provides an electromagnetic heating control method for a heated smoking device, which is used to control the electromagnetic heating circuit of the heated smoking device provided in the first aspect, comprising:

[0029] controlling the duty cycle of the first control signal to enable the boost circuit to boost the voltage until the target voltage is reached;

[0030] controlling the frequencies of the second control signal and the third control signal so that the LC circuit operates in a resonant state;

[0031] The duty ratios of the second control signal and the third control signal are controlled to adjust the heating power of the LC circuit.

[0032] As a preferred solution, the electromagnetic heating circuit further includes a voltage detection module, and the electromagnetic heating control method further includes:

[0033] Acquire the boost voltage of the boost module in real time, and compare the boost voltage with the target voltage;

[0034] When the boost voltage is less than the target voltage, increasing the duty cycle of the first control signal;

[0035] When the boost voltage is greater than or equal to the target voltage, the duty cycle of the first control signal is reduced.

[0036] As a preferred solution, the electromagnetic heating circuit further includes a temperature detection module. Before controlling the duty ratios of the second control signal and the third control signal, the electromagnetic heating control method further includes:

[0037] Obtaining the real-time temperature of the heating module in the LC circuit, and comparing the real-time temperature with the target temperature;

[0038] Controlling the duty cycle of the second control signal and the third control signal to adjust the heating power of the LC circuit includes:

[0039] When the real-time temperature is lower than the target temperature, increasing the duty ratio of the second control signal and the third control signal;

[0040] When the real-time temperature is greater than or equal to the target temperature, the duty ratios of the second control signal and the third control signal are reduced.

[0041] As a preferred solution, the process of controlling the duty ratio of the second control signal and the third control signal further includes:

[0042] Dynamically adjusting the stepping of the duty cycle of the second control signal and the third control signal according to the temperature difference between the real-time temperature and the target temperature;

[0043] When the temperature difference is greater than or equal to the temperature difference threshold, the step of the duty cycle of the second control signal and the third control signal is increased; when the temperature difference is less than the temperature difference threshold, the step of the duty cycle of the second control signal and the third control signal is reduced.

[0044] Based on the same inventive concept, an embodiment of the present application further provides a heating smoking device, comprising the electromagnetic heating circuit and a human-computer interaction interface of the heating smoking device provided in the first aspect, wherein the human-computer interaction interface is used to display the real-time temperature and the set target temperature.

[0045] In summary, the electromagnetic heating circuit for a heated smoking device provided in this application includes a battery cell, a boost module, an LC resonant module, and a control module. The boost module includes a first capacitor, a boost inductor, a first switch, a first pulse width modulation unit, and a diode. The first pulse width modulation unit generates a first control signal. The LC resonant module includes a second capacitor, a second switch, a third switch, a second pulse width modulation unit, a third pulse width modulation unit, and an LC circuit. The second and third pulse width modulation units respectively generate a second control signal and a third control signal having the same frequency and opposite phases. The control module adjusts the duty cycle of the first control signal to adjust the amplitude of the boost voltage. The frequencies of the second and third control signals are adjusted to keep the LC circuit operating in a resonant state, and the duty cycles of the two signals are controlled within a preset control range to adjust the heating power of the LC circuit. This solves the problem of noise generated by the heating circuit when the LC circuit is switched on and off. At the same time, combined with dynamic adjustment of the boost voltage, it can quickly respond to changes in the temperature curve, achieving the purpose of rapid heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of an electromagnetic heating circuit for a heated smoking device provided by the present invention;

[0047] Figure 2 A schematic diagram of another electromagnetic heating circuit for a heated smoking device provided by the present invention;

[0048] Figure 3 A schematic diagram of an electromagnetic heating control method for a heated smoking device provided by the present invention;

[0049] Figure 4 This is a schematic diagram of another electromagnetic heating control method for a heated smoking device provided by the present invention.

[0050] Description of reference numerals:

[0051] 10. Battery cell; 20. Boost module; 30. LC resonance module; 40. Voltage detection module; 50. Temperature detection module; C1. First capacitor; L1. Boost inductor; T1. First switch; P1. First pulse width modulation unit; D. Diode; C2. Second capacitor; T2. Second switch; T3. Third switch; P2. Second pulse width modulation unit; P3. Third pulse width modulation unit; 31. Heating module; C3. Oscillation capacitor; 31. Heating module; L2. Heating inductor; R. Heating tube. DETAILED DESCRIPTION

[0052] The present application will be described in further detail below in conjunction with the accompanying drawings and examples. It will be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application. It should also be noted that, for ease of description, only portions, rather than all, of the structures relevant to the present application are shown in the accompanying drawings. Various modifications and variations can be made in the present application without departing from the spirit or scope of the present application, which will be apparent to those skilled in the art. Therefore, the present application is intended to cover modifications and variations of the present application that fall within the scope of the corresponding claims (technical solutions claimed for protection) and their equivalents. It should be noted that the embodiments provided in the present application examples can be combined with each other without contradiction.

[0053] Figure 1 This is a schematic diagram of an electromagnetic heating circuit for a heated smoking device provided by the present invention. Figure 2 This is a schematic diagram of another electromagnetic heating circuit of a heated smoking device provided by the present invention, with reference to Figure 1-Figure 2 The electromagnetic heating circuit of the heating smoking device provided in the embodiment of the present application includes a battery core 10, a boost module 20, an LC resonance module 30 and a control module ( Figure 1 (not shown). The battery cell 10 is used to provide electrical energy. The boost module 20 includes a first capacitor C1, a boost inductor L1, a first switch T1, a first pulse width modulation unit P1 and a diode D. The first end of the first capacitor C1 is connected to the positive pole of the battery cell 10, and the second end is connected to the negative pole of the battery cell 10, that is, the positive and negative poles of the battery cell 10 are connected in parallel. The first end of the boost inductor L1 is connected to the positive pole of the battery cell 10, and the second end is connected to the input end of the diode D and the first pole of the first switch T1, and the second pole of the first switch T1 is connected to the negative pole of the battery cell 10. Among them, the boost inductor L1 is used to store electrical energy, convert electrical energy into magnetic energy during the charging cycle, convert magnetic energy into electrical energy during the discharging cycle, and increase the boost voltage of the boost module 20 during the alternating process of the charging cycle and the discharging cycle. The first pulse width modulation unit P1 is connected to the control end of the first switch T1, controls the on and off of the first switch T1, and is used to generate a first control signal PWM1.

[0054] Exemplarily, the first switch T1 can adopt a switching MOS tube to act as an electronic switch, and control the charging and discharging of the boost inductor L1 when it is turned on and off. When it is turned on, it controls the output of the battery cell 10; when it is turned off, it controls the battery cell 10 to be cut off. The first pulse width modulation unit P1 can adopt a pulse width modulation (PWM) inverter to output the first control signal PWM1 for boost control to control the on and off of the first switch T1. The present application can control the amplitude of the boost voltage by adjusting the duty cycle of the first control signal PWM1 to achieve the target voltage output.

[0055] The diode D can play a role of reverse cutoff, ensuring that the current at the monitoring point boost does not flow back to the first switch T1.

[0056] The LC resonant module 30 includes a second capacitor C2, a second switch T2, a third switch T3, a second pulse width modulation unit P2, a third pulse width modulation unit P3, and an LC circuit. The first end of the second capacitor C2 is connected to the output end of the diode D, and the second end is connected to the cathode of the battery cell 10. The first electrode of the second switch T2 is connected to the output end of the diode D, and the second electrode is connected to the first end of the LC circuit and the first electrode of the third switch T3. The second electrode of the third switch T3 is connected to the cathode of the battery cell 10 and the second end of the LC circuit. The second pulse width modulation unit P2 is connected to the control end of the second switch T2 to generate a second control signal PWM2 to control the on and off of the second switch T2. The third pulse width modulation unit P3 is connected to the control end of the third switch T3 to generate a third control signal PWM3 to control the on and off of the third switch T3. The second control signal PWM2 and the third control signal PWM3 have the same frequency and opposite phases.

[0057] Specifically, the second pulse width modulation unit P2 and the third pulse width modulation unit P3 also employ pulse width modulation (PWM) inverters. The second control signal PWM2 and the third control signal PWM3 serve as pulse width (PWM) control signals for the LC circuit. The frequencies of the two pulse width control signals (PWM2 and PWM3) align with the resonant frequency of the LC circuit. The two pulse width control signals (PWM2 and PWM3) have the same frequency and opposite phases. The second switch T2 and the third switch T3 can also employ MOS transistors, acting as electronic switches for the LC circuit. By alternating on and off, they form a half-bridge circuit to control the oscillation of the LC circuit.

[0058] Optionally, the LC circuit includes a heating module 31 and an oscillating capacitor C3 connected in series. The heating module 31 includes a heating inductor L2 and a heating tube R. Specifically, the oscillating capacitor C3 cooperates with the heating inductor L2 in the heating module 31 to achieve LC oscillation. When the LC circuit oscillates, the current flowing through the heating inductor L2 generates a magnetic field, and the heating tube R generates heat under the influence of the changing magnetic field, completing the heating action.

[0059] A heating body, such as tobacco or other materials, may be provided inside the heating tube R.

[0060] The control module provided herein is configured to adjust the duty cycle of a first control signal PWM1 to adjust the amplitude of the boost voltage, synchronously adjust the frequencies of a second control signal PWM2 and a third control signal PWM3 to resonate the LC circuit, and control the duty cycles of both signals within a preset control range to adjust the heating power of the LC circuit. The preset control range is 50% to 1%.

[0061] The present application achieves the purpose of temperature control by controlling the switching duty cycle of the LC circuit and dynamically adjusting the energy output to the heating module 31. The preset control range of the duty cycle is 50% to 1%. With this setting, it is less likely that the LC circuit will be shut down, and noise can be avoided.

[0062] The control module may be an integrated circuit (IC), a processor, a microprocessor, or the like, such as a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The control module stores a control program for controlling at least the battery cell 10, the boost module 20, and the LC resonant module 30.

[0063] Based on the same inventive concept, the present application also provides an electromagnetic heating control method for a heated smoking device, which is used to control the electromagnetic heating circuit of the heated smoking device provided in the above embodiment. Figure 2 This is a schematic diagram of an electromagnetic heating control method for a heated smoking device provided by the present invention, with reference to Figure 1 and Figure 2 The electromagnetic heating control method of the electromagnetic heating circuit of the heating smoking device provided in the embodiment of the present application includes:

[0064] S101 , controlling the duty cycle of a first control signal PWM1 to enable a boost circuit to boost voltage until a target voltage is reached.

[0065] Specifically, the first capacitor C1, the boost inductor L1, the first switch T1, the first pulse width modulation unit P1, and the diode D constitute the boost module 20. After the boost module 20 starts working:

[0066] In the initial stage, the voltage of the battery cell 10 is connected to the boost module 20 .

[0067] In the control stage, the control module generates a first control signal PWM1 by adjusting the frequency of the first pulse width modulation unit P1 to drive the first switch T1 to be periodically turned on and off, thereby starting the boost inductor L1 to oscillate.

[0068] During the boost process, when the first switch T1 is turned off, the boost inductor L1 converts electrical energy into magnetic energy during the charging period; when the first switch T1 is turned on, the boost inductor L1 converts magnetic energy into electrical energy during the discharging period.

[0069] Furthermore, the control module dynamically adjusts the duty cycle of the first control signal PWM1 to accurately control the amplitude of the boost voltage until the boost voltage is adjusted to the target voltage. The boost voltage is then filtered by the first capacitor C1 to provide controllable power for the subsequent LC circuit.

[0070] The target voltage refers to the voltage of the LC circuit preset by the system under rated power.

[0071] S102 : Control the frequencies of the second control signal PWM2 and the third control signal PWM3 to make the LC circuit operate in a resonant state.

[0072] Specifically, the second switch T2, the third switch T3, the second pulse width modulation unit P2, the third control signal PWM3 and the LC circuit constitute the LC resonance module 30. At the same time, the second switch T2 and the third switch T3 constitute a half-bridge circuit. After the LC circuit starts oscillating:

[0073] The control module adjusts the frequency of the second pulse-width modulation unit P2 to generate a second control signal PWM2, which drives the second switch T2 to periodically switch on and off. It also adjusts the frequency of the third pulse-width modulation unit P3 to generate a third control signal PWM3, which drives the third switch T3 to periodically switch on and off. The oscillating capacitor C3 cooperates with the heating inductor L2 in the heating module 31 to achieve LC oscillation, and the LC circuit operates in a resonant state. The second control signal PWM2 and the third control signal PWM3 have the same frequency but opposite phases.

[0074] When the LC resonant circuit enters an oscillating state, an alternating current flows through the heating inductor L2, which generates a changing magnetic field. The heating tube R, under the electromagnetic induction of this changing magnetic field, generates eddy currents, which ultimately generate heat through the thermal effect of the eddy currents, completing the entire heating process.

[0075] S103 , controlling the duty ratios of the second control signal PWM2 and the third control signal PWM3 to adjust the heating power of the LC circuit.

[0076] In the resonance stage, the control module controls the duty cycle of the second control signal PWM2 and the third control signal PWM3 to control the power output to the heating module 31 and optimize the entire heating process.

[0077] Based on the above embodiments, Figure 2 The electromagnetic heating circuit of the heated smoking device provided in the embodiment of the present application further includes a voltage detection module 40, connected to the control module and the output end of the diode D, for detecting the boosted voltage of the boost module 20. The control module is further configured to dynamically adjust the duty cycle of the first control signal PWM1 based on the difference between the boosted voltage of the boost module 20 and the target voltage, thereby automatically compensating for the amplitude of the boosted voltage.

[0078] The voltage detection module 40 may be a capacitive voltage sensor, an optical voltage sensor, a resistive voltage divider, etc. For example, the voltage detection module 40 is connected to the detection point Boost in the boost module 20 to measure the boost voltage at the detection point, which is the output voltage of the boost module 20 .

[0079] Specifically, in step S101, during the voltage boosting process, the electromagnetic heating control method further includes:

[0080] Step S11: obtaining the boost voltage of the boost module in real time, and comparing the boost voltage with the target voltage.

[0081] Step S12: When the boost voltage U is less than the target voltage U0, the duty cycle of the first control signal PWM1 is increased to increase the amplitude of the boost voltage.

[0082] Step S12: When the boost voltage U is greater than or equal to the target voltage U0, the duty cycle of the first control signal PWM1 is reduced to lower the amplitude of the boost voltage.

[0083] For example, during the boost and hold phases of the circuit, a capacitive voltage sensor detects the boost voltage U at the test point and converts it into an electrical signal, which is then transmitted to the control module. The control module compares the acquired boost voltage U with the internally stored target voltage U0.

[0084] When U<U0, the duty cycle of the first control signal PWM1 is increased to quickly increase the amplitude of the boost voltage until it reaches the target voltage U0, thereby achieving the purpose of rapid temperature increase.

[0085] When U≥U0, the duty cycle of the first control signal PWM1 is reduced to quickly reduce the amplitude of the boost voltage until it reaches the target voltage U0, thereby achieving the purpose of rapid temperature reduction.

[0086] The present application combines dynamic adjustment of the boost voltage to achieve the purpose of automatically compensating the amplitude of the boost voltage when the cell voltage is low, thereby maintaining the output voltage of the boost module 20 stable.

[0087] Based on the above embodiments, Figure 2 The electromagnetic heating circuit of the heated smoking device provided herein further includes a temperature detection module 50, which is electrically connected to the control module and is configured to detect the real-time temperature of the heating module 31 in the LC circuit. The control module is further configured to dynamically adjust the duty cycle steps of the second control signal PWM2 and the third control signal PWM3 based on the temperature difference between the real-time temperature and the target temperature.

[0088] Specifically, the temperature detection module 50 can be externally connected to a thermistor sensor or an infrared temperature sensor device to detect the real-time temperature of the heating module 31 in the LC circuit and transmit the temperature signal to the control module.

[0089] Figure 4 This is a schematic diagram of another electromagnetic heating control method for a heated smoking device provided by the present invention, referring to Figure 2 and Figure 4 The embodiment of the present application further provides an electromagnetic heating control method for a heating smoking device, the electromagnetic heating control method comprising:

[0090] S201 , controlling the duty cycle of the first control signal PWM1 to enable the boost circuit to boost the voltage until the target voltage is reached.

[0091] For details, please refer to the above Figure 1 and Figure 3 As shown, no further details are given here.

[0092] S202 : Control the frequencies of the second control signal PWM2 and the third control signal PWM3 to make the LC circuit operate in a resonant state.

[0093] For details, please refer to the above Figure 1 and Figure 3 As shown, no further details are given here.

[0094] S203: Obtain the real-time temperature of the heating module in the LC circuit, and compare the real-time temperature with the target temperature.

[0095] S204 : When the real-time temperature is lower than the target temperature, increase the duty ratio of the second control signal PWM2 and the third control signal PWM3 to increase the heating power of the LC circuit.

[0096] S205 : When the real-time temperature is greater than or equal to the target temperature, reduce the duty ratio of the second control signal PWM2 and the third control signal PWM3 to reduce the heating power of the LC circuit.

[0097] For example, a thermistor sensor is used to detect the real-time temperature T of the heating module 31 and convert the real-time temperature T into an electrical signal and transmit it to the control module. The control module compares the acquired real-time temperature T with the internally stored target temperature T0.

[0098] When T < T0, which can also be understood as when the temperature needs to be increased, the duty cycle of the second control signal PWM2 and the third control signal PWM3 is increased, increasing the heating power output to the heating module 31 and prompting the heating tube R to heat up quickly. When T ≥ T0, which can also be understood as when the temperature needs to be lowered, the duty cycle of the second control signal PWM2 and the third control signal PWM3 is reduced, reducing the heating power output to the heating module 31 and prompting the heating tube R to cool down quickly. The energy obtained by the heating module 31 is insufficient to maintain the current temperature, and the heating element inside the heating tube R naturally cools down.

[0099] The present application controls the duty cycle of the second control signal PWM2 and the third control signal PWM3 to prevent the LC circuit from being completely shut down. This means that the current in the LC circuit does not suddenly change from on to off or back to on, thus avoiding noise and improving resonant stability.

[0100] Based on the above embodiment, in the process of controlling the duty ratios of the second control signal and the third control signal, the electromagnetic heating control method further includes:

[0101] Step S21 : dynamically adjusting the stepping of the duty cycle of the second control signal PWM2 and the third control signal PWM3 according to the temperature difference ΔT between the real-time temperature T and the target temperature T0 .

[0102] Step S22: When the temperature difference ΔT ≥ the temperature difference threshold ΔT 阈 , increase the step of the duty cycle of the second control signal PWM2 and the third control signal PWM3.

[0103] Step S23: When the temperature difference ΔT is less than the temperature difference threshold ΔT 阈 , reducing the step of the duty cycle of the second control signal PWM2 and the third control signal PWM3.

[0104] Specifically, in the process of controlling the duty cycle of the second control signal PWM2 and the third control signal PWM3, the control module calculates the temperature difference ΔT=T-T0 according to the difference formula, and compares and determines the temperature difference ΔT with the temperature difference threshold ΔT. 阈 The size relationship.

[0105] When ΔT ≥ ΔT 阈It can also be understood that when the real-time temperature is significantly different from the target temperature, the duty cycle steps of the second control signal PWM2 and the third control signal PWM3 can be increased to allow the temperature of the heating module 31 to quickly approach the target temperature, thereby achieving the purpose of rapid heating or cooling.

[0106] The duty cycle step generally refers to the minimum change in each adjustment when adjusting the duty cycle of a pulse width modulation (PWM) signal, that is, the step size or resolution.

[0107] When ΔT<ΔT 阈 It can also be understood that when the difference between the real-time temperature and the target temperature is small, the duty cycle step of the second control signal PWM2 and the third control signal PWM3 can be reduced to allow the temperature of the heating module 31 to slowly approach the target temperature, thereby achieving the purpose of slow heating or cooling, thereby avoiding the problem of overshoot caused by the real-time temperature deviating from the target temperature.

[0108] In summary, this application sets the frequency and duty cycle of the second control signal and the third control signal so that the current in the LC circuit will not change suddenly, thereby improving the ripple of the boost circuit and improving the accuracy of the boost voltage measurement, thereby accurately controlling the output power and making the heating element temperature of the heating module closer to the target temperature.

[0109] Based on the same inventive concept, the present application also provides a heated smoking device, comprising the electromagnetic heating circuit and human-computer interaction interface of the heated smoking device provided in the above-mentioned embodiment. The human-computer interaction interface is configured to display the real-time temperature and the set target temperature. The heated element is heated using the electromagnetic heating control method of the heated smoking device provided in the above-mentioned embodiment. This heated smoking device also achieves the beneficial effects achieved by the electromagnetic heating circuit and control method provided in the above-mentioned embodiment, which will not be further elaborated here.

[0110] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and the features of the various embodiments of the present invention may be partially or completely coupled or combined with each other, and may cooperate with each other in various ways and be technically driven. It is possible for those skilled in the art to make various obvious changes, readjustments, combinations and substitutions without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An electromagnetic heating circuit for heating a smoking device, characterized in that: include: Battery cells, used to provide electrical energy; Boost module, including: a first capacitor, a first end of which is connected to the positive electrode of the battery cell, and a second end of which is connected to the negative electrode of the battery cell; a boost inductor, a first end of which is connected to the positive electrode of the battery cell, and a second end of which is connected to the input end of the diode and the first electrode of the first switch; a first pulse width modulation unit, connected to the control end of the first switch, for generating a first control signal; LC resonance module, including: a second capacitor, a first end of which is connected to the output end of the diode and the first electrode of the second switch; a second electrode of the second switch is connected to the first electrode of the third switch and the first end of the LC circuit; and a negative electrode of the battery cell is further connected to the second electrode of the first switch, the second end of the second capacitor, the second electrode of the third switch, and the second end of the LC circuit; a second pulse width modulation unit, connected to the control terminal of the second switch, and configured to generate a second control signal; a third pulse width modulation unit, connected to the control terminal of the third switch, and configured to generate a third control signal; Wherein, the second control signal and the third control signal have the same frequency and opposite phase; Control module, configured as: adjusting the duty cycle of the first control signal to adjust the amplitude of the boost voltage; The frequencies of the second control signal and the third control signal are adjusted to make the LC circuit operate in a resonant state, and the duty ratios of the two are controlled within a preset control range to adjust the heating power of the LC circuit.

2. The electromagnetic heating circuit according to claim 1, characterized in that: The LC circuit includes a heating module and an oscillating capacitor connected in series, and the heating module includes a heating inductor and a heating tube.

3. The electromagnetic heating circuit according to claim 1, characterized in that: The first switch, the second switch and the third switch include switch MOS tubes; When the battery is turned on, the battery cell output is controlled; when the battery is turned off, the battery cell is controlled to be cut off.

4. The electromagnetic heating circuit according to claim 1, characterized in that: Also includes; a temperature detection module, electrically connected to the control module, for detecting the real-time temperature of the heating module in the LC circuit; The control module is further configured to dynamically adjust the stepping of the duty cycles of the second control signal and the third control signal according to the temperature difference between the real-time temperature and the target temperature.

5. The electromagnetic heating circuit according to claim 1, characterized in that: Also includes; a voltage detection module, connected to the output ends of the control module and the diode, respectively, for detecting the boost voltage of the boost module; The control module is further configured to dynamically adjust the duty cycle of the first control signal according to a difference between the boost voltage and the target voltage, so as to automatically compensate for the amplitude of the boost voltage.

6. A method for controlling electromagnetic heating of a heated smoking article, for controlling the electromagnetic heating circuit of the heated smoking article according to any one of claims 1 to 5, characterized in that: include: controlling the duty cycle of the first control signal to enable the boost circuit to boost the voltage until the target voltage is reached; controlling the frequencies of the second control signal and the third control signal so that the LC circuit operates in a resonant state; The duty ratios of the second control signal and the third control signal are controlled to adjust the heating power of the LC circuit.

7. The electromagnetic heating control method according to claim 6, characterized in that: Also includes a voltage detection module, and also includes: Acquire the boost voltage of the boost module in real time, and compare the boost voltage with the target voltage; When the boost voltage is less than the target voltage, increasing the duty cycle of the first control signal; When the boost voltage is greater than or equal to the target voltage, the duty cycle of the first control signal is reduced.

8. The electromagnetic heating control method according to claim 6, characterized in that: The system further includes a temperature detection module, and before controlling the duty cycle of the second control signal and the third control signal, further includes: Obtaining the real-time temperature of the heating module in the LC circuit, and comparing the real-time temperature with the target temperature; Controlling the duty cycle of the second control signal and the third control signal to adjust the heating power of the LC circuit includes: When the real-time temperature is lower than the target temperature, increasing the duty ratio of the second control signal and the third control signal; When the real-time temperature is greater than or equal to the target temperature, the duty ratios of the second control signal and the third control signal are reduced.

9. The electromagnetic heating control method according to claim 8, characterized in that: The process of controlling the duty ratio of the second control signal and the third control signal further includes: Dynamically adjusting the stepping of the duty cycle of the second control signal and the third control signal according to the temperature difference between the real-time temperature and the target temperature; When the temperature difference is greater than or equal to the temperature difference threshold, the step of the duty cycle of the second control signal and the third control signal is increased; when the temperature difference is less than the temperature difference threshold, the step of the duty cycle of the second control signal and the third control signal is reduced.

10. A heated smoking device, characterized in that: include: The electromagnetic heating circuit of the heated smoking device according to any one of claims 1 to 5; Human-computer interaction interface, used to display real-time temperature and set target temperature.

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