Heating control circuit of heating element and aerosol heating device
By introducing a heating control circuit into the aerosol generating device and utilizing the combination of a delay circuit and a switching transistor, the safety issues caused by abnormal heating were resolved, thus improving safety.
Patent Information
- Application Number
- CN202423207118.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2034-12-23
AI Technical Summary
When existing aerosol generating devices malfunction, the heating element may continue to heat up, potentially causing safety issues such as burns or fires.
A heating control circuit is adopted, including a switching transistor, a signal input terminal, a driving circuit, and a delay circuit. When the heating signal is maintained for a longer time than a preset delay time, the delay circuit outputs a second delay signal to control the switching transistor to turn off and prevent the heating element from heating.
This effectively avoids safety issues such as burns or fires caused by abnormal heating, and improves the safety of aerosol generation devices.
Smart Images
Figure CN223745811U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] Embodiments of the present application relate to the technical field of heating control, in particular to a heating control circuit of a heating element and an aerosol generating device. BACKGROUND
[0002] In a prior art example, a user applies a puffing action to an aerosol generating device, and the aerosol generating device generates a heating signal in response to the puffing action to control a heating element to start heating, thereby atomizing an aerosol generating substrate to produce a smokeable aerosol. However, when the aerosol generating device has a heating abnormality, the heating signal continues to be output, causing the heating element to continue heating, which may cause a burn or a fire, etc. SUMMARY
[0003] The present application provides a heating control circuit of a heating element and an aerosol generating device, which can avoid burn or fire, etc. caused by heating abnormality, and improve safety.
[0004] At least one embodiment of the present application provides a heating control circuit of a heating element, comprising a switching tube electrically connected to the heating element, the heating control circuit further comprising a signal input end and a driving circuit for controlling the on-off of the switching tube, the driving circuit having a first input end, a second input end and an output end connected to the switching tube;
[0005] wherein the first input end is electrically connected to the signal input end to establish a first signal branch, the second input end is electrically connected to the signal input end to establish a second signal branch, and a delay circuit is provided on the second signal branch;
[0006] The signal input end is configured to receive a heating signal;
[0007] The delay circuit is configured to output a first delay signal to the second input end when the maintenance time of the heating signal does not exceed a preset delay time, and output a second delay signal to the second input end when the maintenance time of the heating signal exceeds the preset delay time;
[0008] The driving circuit is configured to control the switching tube to turn on or off based on the heating signal from the first signal branch and the first delay signal from the second signal branch, thereby allowing the heating element to start heating; and control the switching tube to turn off based on the heating signal from the first signal branch and the second delay signal from the second signal branch, thereby prohibiting the heating element to start heating.
[0009] As an example, a shaping circuit is further arranged in the second signal branch, and the shaping circuit and the delay circuit are sequentially electrically connected between the signal input end and the second input end, and the shaping circuit is configured to shape the heating signal into a high-level signal and deliver the high-level signal to the delay circuit.
[0010] As an example, the shaping circuit comprises a first diode, a first non-inverting Schmitt trigger, a first resistor, a second resistor and a first capacitor.
[0011] The anode of the first diode is electrically connected to the signal input end, the cathode of the first diode is electrically connected to the input end of the first non-inverting Schmitt trigger, the output end of the first non-inverting Schmitt trigger is electrically connected to the delay circuit, the first resistor is connected in parallel with the first diode, the second resistor is electrically connected between the signal input end and a ground end, and is electrically connected to one end of the first resistor, and the first capacitor is electrically connected between the cathode of the first diode and the ground end, and is electrically connected to the other end of the first resistor.
[0012] As an example, the delay circuit is an RC delay circuit comprising a Schmitt trigger.
[0013] As an example, the delay circuit comprises a second diode, an inverting Schmitt trigger, a third resistor and a second capacitor.
[0014] The cathode of the second diode is electrically connected to the shaping circuit, the anode of the second diode is electrically connected to the input end of the inverting Schmitt trigger, the output end of the inverting Schmitt trigger is electrically connected to the second input end, one end of the third resistor is electrically connected to the cathode of the second diode and the shaping circuit respectively, the other end of the third resistor is electrically connected to the anode of the second diode, the input end of the inverting Schmitt trigger and one end of the second capacitor respectively, and the other end of the second capacitor is grounded.
[0015] As an example, the third resistor and the second capacitor satisfy the following formula:
[0016] V t = E x [1-exp(-t / R3C2)]
[0017] Wherein, V t is the high-level threshold of the inverting Schmitt trigger, E is the voltage value of the high-level signal, t is the preset delay time, R3 is the resistance value of the third resistor, and C2 is the capacitance value of the second capacitor.
[0018] As an example, the driving circuit comprises an NAND gate, and the switch tube comprises a PMOS tube.
[0019] one input end of the NAND gate is the first input end and is electrically connected to the signal input end, another input end of the NAND gate is the second input end and is electrically connected to the output end of the inverting Schmitt trigger, the output end of the NAND gate is electrically connected to the gate of the PMOS tube, the drain of the PMOS tube is electrically connected to a power supply, and the source of the PMOS tube is grounded through the heat generating element.
[0020] As an example, the driving circuit includes an AND gate, and the switch tube includes an NMOS tube.
[0021] one input end of the NAND gate is the first input end and is electrically connected to the signal input end, another input end of the NAND gate is the second input end and is electrically connected to the output end of the inverting Schmitt trigger, the output end of the NAND gate is electrically connected to the gate of the PMOS tube, the drain of the PMOS tube is electrically connected to a power supply, and the source of the PMOS tube is grounded through the heat generating element.
[0022] As an example, the delay circuit includes a third diode, a second non-inverting Schmitt trigger, a fourth resistor and a third capacitor.
[0023] The cathode of the third diode is electrically connected to the shaping circuit, the anode of the third diode is electrically connected to the input end of the second non-inverting Schmitt trigger, the output end of the second non-inverting Schmitt trigger is electrically connected to the second input end, one end of the fourth resistor is electrically connected to the cathode of the third diode and the shaping circuit respectively, the other end of the fourth resistor is electrically connected to the anode of the third diode, the input end of the second non-inverting Schmitt trigger and one end of the third capacitor respectively, and the other end of the third capacitor is grounded.
[0024] As an example, the driving circuit includes an OR gate, and the switch tube includes an NMOS tube.
[0025] one input end of the OR gate is the first input end and is electrically connected to the signal input end, another input end of the OR gate is the second input end and is electrically connected to the output end of the second non-inverting Schmitt trigger, the output end of the OR gate is electrically connected to the gate of the NMOS tube, the drain of the NMOS tube is electrically connected to a power supply through the heat generating element, and the source of the NMOS tube is grounded.
[0026] At least one embodiment of the present application provides an aerosol generating device, which comprises a controller, a heat generating element and a heating control circuit as described in any embodiment of the present application, the heating control circuit being electrically connected between the controller and the heat generating element.
[0027] The beneficial effects of the embodiments of the present application are that: the heating control circuit of the heating element and the aerosol generating device provided by the above embodiments include a signal input end configured to receive a heating signal, further include a first signal branch established by electrically connecting a first input end of a driving circuit to the signal input end, a second signal branch established by electrically connecting a second input end of the driving circuit to the signal input end, and a delay circuit arranged on the second signal branch, and an output end of the driving circuit is connected with a switching tube for controlling the switching tube to turn on and off; the delay circuit is configured to output a second delay signal to the second input end when the maintenance time of the heating signal exceeds the preset delay time, and the driving circuit is configured to control the switching tube to turn off based on the heating signal from the first signal branch and the second delay signal from the second signal branch, thereby prohibiting the heating element from starting heating, thereby avoiding safety problems such as scalding or fire caused by abnormal heating, and improving safety. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application, the drawings needed in the specific embodiment description will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.
[0029] Figure 1 is a circuit structure schematic diagram of a heating control circuit of a heating element provided by an embodiment of the present application;
[0030] Figure 2 is a circuit structure schematic diagram of another heating control circuit of a heating element provided by an embodiment of the present application;
[0031] Figure 3 is a circuit connection schematic diagram of a heating control circuit of a heating element provided by an embodiment of the present application;
[0032] Figure 4 is a circuit connection schematic diagram of another heating control circuit of a heating element provided by an embodiment of the present application;
[0033] Figure 5 is a circuit connection schematic diagram of another heating control circuit of a heating element provided by an embodiment of the present application;
[0034] Figure 6 is a circuit structure schematic diagram of an aerosol generating device provided by an embodiment of the present application. DETAILED DESCRIPTION
[0035] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.
[0036] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the present application includes any and all combinations of one or more related listed items.
[0037] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.
[0038] Please refer to Figure 1 A heating control circuit of a heating element is provided for the embodiments of the present application. As shown in Figure 1 The heating control circuit 10 includes a switching tube 11 electrically connected to the heating element 20. The heating control circuit 10 further includes a signal input end 12 and a driving circuit 13 for controlling the on-off of the switching tube 11. The driving circuit 13 has a first input end 131, a second input end 132 and an output end 133 connected to the switching tube 11. The first input end 131 is electrically connected to the signal input end 12 to establish a first signal branch. The second input end 132 is electrically connected to the signal input end 12 to establish a second signal branch. A delay circuit 14 is provided on the second signal branch.
[0039] The signal input end 12 is configured to receive a heating signal. The delay circuit 14 is configured to output a first delay signal to the second input end 132 when the maintenance time of the heating signal does not exceed the preset delay time, and output a second delay signal to the second input end 132 when the maintenance time of the heating signal exceeds the preset delay time. The driving circuit 13 is configured to control the switching tube 11 to be turned on or off based on the heating signal from the first signal branch and the first delay signal from the second signal branch, thereby allowing the heating element 20 to start heating; and control the switching tube 11 to be turned off based on the heating signal from the first signal branch and the second delay signal from the second signal branch, thereby prohibiting the heating element 20 to start heating.
[0040] In summary, the heating control circuit 10 is configured to output the second delay signal to the second input end 132 when the maintaining time of the heating signal exceeds the preset delay time through the delay circuit 14, and the driving circuit 13 is configured to control the switch tube 11 to be closed based on the heating signal from the first signal branch and the second delay signal from the second signal branch, so as to prohibit the heating element 20 from starting heating, thereby avoiding safety problems such as scalding or fire caused by abnormal heating, and improving safety.
[0041] The switch tube 11 can be a switching device such as a MOS tube, a field effect tube, a thyristor, a triac, a transistor, an IGBT tube, etc.
[0042] For example, when the maintaining time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and the heating of the heating element 20 is allowed by controlling the MOS tube to be opened and closed through the chopping control, so as to realize normal heating of the heating element 20. When the maintaining time of the heating signal exceeds the preset delay time, the heating control circuit 10 is in an abnormal heating state, and the heating of the heating element 20 is prohibited by controlling the MOS tube to be closed, so as to realize termination of heating of the heating element 20. In some embodiments, the heating signal is a continuous low-level signal (or the duty ratio of the PWM signal is 0), and the heating of the heating element 20 is prohibited by controlling the MOS tube to be closed.
[0043] The heating signal includes a PWM signal or a continuous high-level signal.
[0044] Generally, in an aerosol generating device with power adjustment, the heating control circuit 10 is supplied with a PWM signal by a controller of the aerosol generating device, and then the heating of the heating element 20 is allowed by controlling the switch tube 11 to be opened and closed through the chopping control, and the heating power of the heating element 20 is adjusted according to the resistance value of the heating element 20 in the process of normal heating of the heating element 20, so as to realize normal heating of the heating element 20 with adjustable power. In an aerosol generating device without power adjustment, the heating control circuit 10 is supplied with a continuous high-level signal by a controller of the aerosol generating device, and then the heating of the heating element 20 is allowed by controlling the switch tube 11 to be opened and closed through the chopping control, so as to realize normal heating of the heating element 20 at a preset power.
[0045] In some embodiments, please refer to Figure 2The second signal branch is further provided with a shaping circuit 15, the shaping circuit 15 and the delay circuit 14 are sequentially electrically connected between the signal input end 12 and the second input end 132, and the shaping circuit 15 is configured to shape the heating signal into a high-level signal and deliver the high-level signal to the delay circuit 14.
[0046] As shown in any one of the accompanying drawings, Figures 3 to 5 The shaping circuit 15 includes a first diode D1, a first non-inverting Schmitt trigger U1, a first resistor R1, a second resistor R2 and a first capacitor C1. The anode of the first diode D1 is electrically connected to the signal input end 12, the cathode of the first diode D1 is electrically connected to the input end of the first non-inverting Schmitt trigger U1, the output end of the first non-inverting Schmitt trigger U1 is electrically connected to the delay circuit 14, the first resistor R1 is connected in parallel with the first diode D1, the second resistor R2 is electrically connected between the signal input end 12 and the ground end, and is electrically connected to one end of the first resistor R1, and the first capacitor C1 is electrically connected between the cathode of the first diode D1 and the ground end, and is electrically connected to the other end of the first resistor R1.
[0047] Among them, the first diode D1, the first resistor R1, the first capacitor C1 and the second resistor R2 constitute a charge-discharge circuit.
[0048] The first non-inverting Schmitt trigger U1 has a high-level threshold and a low-level threshold. When the input voltage (voltage across the first capacitor C1) of the first non-inverting Schmitt trigger U1 is higher than the high-level threshold of the first non-inverting Schmitt trigger U1, the first non-inverting Schmitt trigger U1 outputs high (i.e. outputs a high-level signal); when the input voltage (voltage across the first capacitor C1) of the first non-inverting Schmitt trigger U1 is lower than the low-level threshold of the first non-inverting Schmitt trigger U1, the first non-inverting Schmitt trigger U1 outputs low (i.e. outputs a low-level signal); when the input voltage (voltage across the first capacitor C1) of the first non-inverting Schmitt trigger U1 is between the low-level threshold and the high-level threshold of the first non-inverting Schmitt trigger U1, the first non-inverting Schmitt trigger U1 output remains unchanged.
[0049] It can be seen that the first non-inverting Schmitt trigger U1 has a hysteresis characteristic, which can be applied in a circuit to achieve an anti-interference effect, and can also be applied in a circuit to achieve a buffering effect.
[0050] Taking a heating signal including a PWM signal as an example, the PWM signal is input to the signal input terminal 12, and then enters the first signal branch and the second signal branch respectively. For the second signal branch, during the high-level period of the PWM signal, the PWM signal charges the first capacitor C1 quickly through the first diode D1, and the voltage at the input terminal of the first non-inverting Schmitt trigger U1 is equal to the voltage across the first capacitor C1, thus making the input terminal of the first non-inverting Schmitt trigger U1 a high-level signal; during the low-level period of the PWM signal, the first capacitor C1 discharges through the first resistor R1 and the second resistor R2. By setting the first resistor R1 to a large resistance value, the voltage across the first capacitor C1 remains high when the next high-level period of the PWM signal arrives, thus keeping the input terminal of the first non-inverting Schmitt trigger U1 a high-level signal. Therefore, the shaping circuit 15 shapes the PWM signal into a high-level signal and delivers it to the delay circuit 14.
[0051] Regarding the value of the first resistor R1, it is only necessary to ensure that during the discharge process of the first capacitor C1, the voltage across the first capacitor C1 is not lower than the low-level threshold of the first in-phase Schmitt trigger U1.
[0052] Since the second resistor R2 is electrically connected between the signal input terminal 12 and the ground terminal, during the low level of the PWM signal, the first capacitor C1 discharges to the ground terminal through the first resistor R1 and the second resistor R2. On the one hand, the discharge efficiency is higher; on the other hand, it avoids the first capacitor C1 from discharging to the signal input terminal 12 through the first resistor R1 and the second resistor R2, thus protecting the controller electrically connected to the signal input terminal 12 and achieving isolation between the heating control circuit 10 and the controller during the discharge of the first capacitor C1.
[0053] In some embodiments, the delay circuit 14 is an RC delay circuit 14 including a Schmitt trigger.
[0054] As an example, such as Figure 3 or Figure 4 As shown, the delay circuit 14 includes a second diode D2, an inverting Schmitt trigger U2, a third resistor R3, and a second capacitor C2. The cathode of the second diode D2 is electrically connected to the shaping circuit 15 (the output terminal of the first non-inverting Schmitt trigger U1), the anode of the second diode D2 is electrically connected to the input terminal of the inverting Schmitt trigger U2, and the output terminal of the inverting Schmitt trigger U2 is electrically connected to the second input terminal 132. One end of the third resistor R3 is electrically connected to the cathode of the second diode D2 and the shaping circuit 15 (the output terminal of the first non-inverting Schmitt trigger U1), and the other end of the third resistor R3 is electrically connected to the anode of the second diode D2, the input terminal of the inverting Schmitt trigger U2, and one end of the second capacitor C2. The other end of the second capacitor C2 is grounded.
[0055] In some embodiments, the second diode D2 can be omitted.
[0056] The first non-inverting Schmitt trigger U1 outputs a high level signal, and charges the second capacitor C2 through the third resistor R3. The voltage across the second capacitor C2 rises and is equal to the voltage at the input of the inverting Schmitt trigger U2. The inverting Schmitt trigger U2 has a high level threshold and a low level threshold. When the input voltage of the inverting Schmitt trigger U2 (the voltage across the second capacitor C2) is higher than the high level threshold of the inverting Schmitt trigger U2, the inverting Schmitt trigger U2 outputs low (i.e. outputs a low level signal); when the input voltage of the inverting Schmitt trigger U2 (the voltage across the second capacitor C2) is lower than the low level threshold of the inverting Schmitt trigger U2, the inverting Schmitt trigger U2 outputs high (i.e. outputs a high level signal); when the input voltage of the inverting Schmitt trigger U2 (the voltage across the second capacitor C2) is between the low level threshold and the high level threshold of the inverting Schmitt trigger U2, the output of the inverting Schmitt trigger U2 remains unchanged.
[0057] In one example, the third resistor R3 and the second capacitor C2 satisfy the following formula:
[0058] V t = E x [1-exp(-t / R3C2)] (Formula 1)
[0059] wherein V t is the high level threshold of the inverting Schmitt trigger, E is the voltage value of the high level signal, t is the preset delay time, R3 is the resistance value of the third resistor R3, and C2 is the capacitance value of the second capacitor C2.
[0060] It can be seen that the preset delay time is determined by the values of the third resistor R3 and the second capacitor C2.
[0061] When the maintenance time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and when the voltage across the second capacitor C2 is lower than the low level threshold of the inverting Schmitt trigger U2, the inverting Schmitt trigger U2 outputs high (i.e. outputs a high level signal); when the maintenance time of the heating signal exceeds the preset delay time, the heating control circuit 10 is in an abnormal heating state, and when the voltage across the second capacitor C2 is higher than the high level threshold of the inverting Schmitt trigger U2, the inverting Schmitt trigger U2 outputs low (i.e. outputs a low level signal).
[0062] On the basis of the above delay circuit 14, the driving circuit 13 comprises a NAND gate U3, and the switch tube 11 comprises a PMOS tube Q1. One input end of the NAND gate U3 is as a first input end 131 and is electrically connected to the signal input end 12, and the other input end of the NAND gate U3 is as a second input end 132 and is electrically connected to the output end of the inverting Schmitt trigger U2, and the output end 133 of the NAND gate U3 is electrically connected to the gate of the PMOS tube Q1, the drain of the PMOS tube Q1 is electrically connected to the power supply VCC, and the source of the PMOS tube Q1 is connected to the ground through the heat generating element 20.
[0063] Figure 3 The working principle of the heating control circuit 10 shown is roughly as follows:
[0064] Taking the heating signal comprising a PWM signal as an example, the PWM signal is input to the signal input end 12 and enters the first signal branch and the second signal branch through the signal input end 12 respectively. In the first signal branch, the PWM signal reaches the first input end 131 of the NAND gate U3. In the second signal branch, the shaping circuit 15 shapes the PWM signal into a high level signal and delivers it to the delay circuit 14, that is, the first non-inverting Schmitt trigger U1 outputs a high level signal.
[0065] When the maintaining time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and after the delay processing of the delay circuit 14, the inverting Schmitt trigger U2 outputs a high level signal to the second input end 132 of the NAND gate U3, therefore, the output end 133 of the NAND gate U3 outputs a low level signal during the high level signal of the PWM signal and outputs a high level signal during the low level signal of the PWM signal, that is, the output end 133 of the NAND gate U3 outputs a chopping signal and delivers it to the gate of the PMOS tube Q1, controls the PMOS tube Q1 to open and close, and thus allows the heat generating element RL1 to start heating.
[0066] When the maintaining time of the heating signal exceeds the preset delay time, the heating control circuit 10 is in an abnormal heating state, and after the delay processing of the delay circuit 14, the inverting Schmitt trigger U2 outputs a low level signal to the second input end 132 of the NAND gate U3, at this time, no matter whether the first input end 131 of the NAND gate U3 is a high level signal or a low level signal, the output end 133 of the NAND gate U3 outputs a high level signal and delivers it to the gate of the PMOS tube Q1, controls the PMOS tube Q1 to close, and turns off the heating circuit of the heat generating element RL1, so that the heat generating element RL1 stops heating.
[0067] In Figure 3 On the basis of the shaping circuit 15 and the delay circuit 14, as Figure 4As shown, the driving circuit 13 comprises an AND gate U4, and the switch tube 11 comprises an NMOS tube Q2. One input end of the AND gate U4 is the first input end 131 and is electrically connected to the signal input end 12, and the other input end of the AND gate U4 is the second input end 132 and is electrically connected to the output end of the inverting Schmitt trigger U2, the output end 133 of the AND gate U4 is electrically connected to the gate of the NMOS tube Q2, the drain of the NMOS tube Q2 is electrically connected to the power supply VCC through the heating element 20, and the source of the NMOS tube Q2 is grounded.
[0068] Figure 4 The working principle of the heating control circuit 10 shown is roughly as follows:
[0069] Taking the heating signal comprising a PWM signal as an example, the PWM signal is input to the signal input end 12 and enters the first signal branch and the second signal branch through the signal input end 12 respectively. In the first signal branch, the PWM signal reaches the first input end 131 of the AND gate U4. In the second signal branch, the shaping circuit 15 shapes the PWM signal into a high-level signal and delivers it to the delay circuit 14, i.e. the first non-inverting Schmitt trigger U1 outputs a high-level signal.
[0070] When the maintaining time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and after the delay processing of the delay circuit 14, the inverting Schmitt trigger U2 outputs a high-level signal to the second input end 132 of the AND gate U4, therefore, the output end 133 of the AND gate U4 outputs a high-level signal during the high-level signal of the PWM signal and outputs a low-level signal during the low-level signal of the PWM signal, i.e. the output end 133 of the NAND gate U3 outputs a chopping signal and delivers it to the gate of the NMOS tube Q2, controlling the NMOS tube Q2 to open and close, thereby allowing the heating element RL1 to start heating.
[0071] When the maintaining time of the heating signal exceeds the preset delay time, the heating control circuit 10 is in an abnormal heating state, and after the delay processing of the delay circuit 14, the inverting Schmitt trigger U2 outputs a low-level signal to the second input end 132 of the AND gate U4, at this time, no matter whether the first input end 131 of the NAND gate U3 is a high-level signal or a low-level signal, the output end 133 of the AND gate U4 outputs a low-level signal and delivers it to the gate of the NMOS tube Q2, controlling the NMOS tube Q2 to close, shutting down the heating circuit of the heating element RL1, so that the heating element RL1 stops heating.
[0072] As an example, on the basis of the above-mentioned shaping circuit 15, as shown in Figure 5 As shown, the delay circuit 14 comprises a third diode D3, a second non-inverting Schmitt trigger U5, a fourth resistor R4 and a third capacitor C3. The driving circuit 13 comprises a NAND gate U6, and the switch tube 11 comprises an NMOS tube Q3.
[0073] The cathode of the third diode D3 is electrically connected with the shaping circuit 15 (the output terminal of the first same-phase Schmitt trigger U1), the anode of the third diode D3 is electrically connected with the input terminal of the second same-phase Schmitt trigger U5, the output terminal of the second same-phase Schmitt trigger U5 is electrically connected with the second input terminal 132, one end of the fourth resistor R4 is respectively electrically connected with the cathode of the third diode D3 and the shaping circuit 15 (the output terminal of the first same-phase Schmitt trigger U1), the other end of the fourth resistor R4 is respectively electrically connected with the anode of the third diode D3, the input terminal of the second same-phase Schmitt trigger U5 and one end of the third capacitor C3, the other end of the third capacitor C3 is grounded.
[0074] In some embodiments, the third diode D3 can be omitted.
[0075] The first same-phase Schmitt trigger U1 outputs a high-level signal, and charges the third capacitor C3 through the fourth resistor R4, the voltage across the third capacitor C3 rises, and is equal to the voltage at the input terminal of the second same-phase Schmitt trigger U5. The second same-phase Schmitt trigger U5 has a high-level threshold and a low-level threshold. When the input voltage of the second same-phase Schmitt trigger U5 (the voltage across the third capacitor C3) is higher than the high-level threshold of the second same-phase Schmitt trigger U5, the second same-phase Schmitt trigger U5 outputs high (i.e. outputs a high-level signal); when the input voltage of the second same-phase Schmitt trigger U5 (the voltage across the third capacitor C3) is lower than the low-level threshold of the second same-phase Schmitt trigger U5, the second same-phase Schmitt trigger U5 outputs low (i.e. outputs a low-level signal); when the input voltage of the second same-phase Schmitt trigger U5 (the voltage across the third capacitor C3) is between the low-level threshold and the high-level threshold of the second same-phase Schmitt trigger U5, the output of the second same-phase Schmitt trigger U5 remains unchanged.
[0076] As an example, the values of the fourth resistor R4 and the third capacitor C3 satisfy the following formula:
[0077] V t1 = E1 x [1-exp(-t / R4C3)] (Formula 2)
[0078] Wherein, V t1 is the high-level threshold of the second same-phase Schmitt trigger U5, E is the voltage value of the high-level signal, t is the preset delay time, R4 is the resistance value of the fourth resistor R4, and C3 is the capacitance value of the third capacitor C3.
[0079] It can be seen that the preset delay time is determined by the values of the fourth resistor R4 and the third capacitor C3.
[0080] When the maintaining time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and when the voltage across the third capacitor C3 is lower than the low level threshold of the second non-inverting Schmitt trigger U5, the second non-inverting Schmitt trigger U5 outputs low (i.e. outputs a low level signal).
[0081] One input end of the NOR gate U6 is electrically connected to the signal input end 12 as the first input end 131, and the other input end of the NOR gate U6 is electrically connected to the output end of the second non-inverting Schmitt trigger U5 as the second input end 132, and the output end 133 of the NOR gate U6 is electrically connected to the gate of the NMOS tube Q3, the drain of the NMOS tube Q3 is electrically connected to the heating element 20, and the source of the NMOS tube Q3 is grounded.
[0082] Figure 5 The working principle of the heating control circuit 10 is roughly as follows:
[0083] Taking the heating signal including a PWM signal as an example, the PWM signal is input to the signal input end 12 and enters the first signal branch and the second signal branch through the signal input end 12. In the first signal branch, the PWM signal reaches the first input end 131 of the NOR gate U6. In the second signal branch, the shaping circuit 15 shapes the PWM signal into a high level signal and delivers it to the delay circuit 14, i.e. the first non-inverting Schmitt trigger U1 outputs a high level signal.
[0084] When the maintaining time of the heating signal does not exceed the preset delay time, the heating control circuit 10 is in a normal heating state, and after the delay processing of the delay circuit 14, the second non-inverting Schmitt trigger U5 outputs a low level signal to the second input end 132 of the NOR gate U6, so that the output end 133 of the NOR gate U6 outputs a low level signal during the high level signal of the PWM signal and outputs a high level signal during the low level signal of the PWM signal, i.e. the output end 133 of the NOR gate U3 outputs a chopping signal and delivers it to the gate of the NMOS tube Q3, which controls the opening and closing of the NMOS tube Q3, thereby allowing the heating element RL1 to start heating.
[0085] When the maintaining time of the heating signal exceeds the preset delay time, the heating control circuit 10 is in an abnormal heating state, and after the delay processing of the delay circuit 14, the second non-inverting Schmitt trigger U5 outputs a high-level signal to the second input end 132 of the NOR gate U6, at this time, no matter whether the first input end 131 of the NOR gate U6 is a high-level signal or a low-level signal, the output end 133 of the NOR gate U6 outputs a low-level signal and is delivered to the gate of the NMOS tube Q3, controlling the NMOS tube Q3 to be closed, turning off the heating circuit of the heating element RL1, so that the heating element RL1 stops heating.
[0086] Please refer to Figure 6 An aerosol-generating device is provided for embodiments of the present application. As shown in Figure 6 The aerosol-generating device 100 includes a controller 30, a heating element 20, and a heating control circuit 10 according to any embodiment of the present application, and the heating control circuit 10 is electrically connected between the controller 30 and the heating element 20.
[0087] The heating element 20 can be a central heating type or a peripheral heating type. The heating element 20 can also heat the aerosol-generating substrate by one or more of heat conduction, electromagnetic induction, chemical change, infrared heating, resonance, photoelectric conversion, and photothermal conversion to generate an aerosol.
[0088] In one example, the heating element 20 is a component for heating a liquid aerosol-forming substrate delivered by a liquid delivery unit. For example, the heating element 20 can be a metal wire, a metal plate, a ceramic heater, etc., but is not limited thereto. In addition, the heating element 20 can be composed of an electrically conductive heating wire such as a nichrome wire, and can be provided to be wound around the structure of the liquid delivery unit. The heating element 20 can be heated by current supply and deliver heat to the liquid aerosol-forming substrate in contact with the heating element 20 to heat the liquid aerosol-forming substrate, thereby generating an aerosol. In one example, the heating element 20 is configured to heat around at least a portion of the aerosol-generating article, i.e., so-called circumferential heating or peripheral heating, etc., which is also possible.
[0089] The controller 30 can be provided on a circuit board to control the overall operation of the aerosol-generating device 100. In detail, the controller 30 not only controls the operation of the heating control circuit 10, but also controls the operation of other elements in the aerosol-generating device 100. In addition, the controller 30 can determine whether the aerosol-generating device 100 can operate by checking the state of the components of the aerosol-generating device 100.
[0090] In some embodiments, the controller 30 can be a general processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a microcontroller, an ARM (Acorn RISC Machine), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. Also, the controller 30 can be any conventional processor, controller, microcontroller, or state machine. The controller 30 can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP, and / or any other such configuration.
[0091] It should be noted that the aerosol-generating device 100 provided by the above embodiments has the circuit structure or circuit connection of the heating control circuit 10 of any embodiment of the present application, thereby having the corresponding beneficial effects. To avoid repetition, the relevant description is omitted.
[0092] The above description is merely exemplary of the application, and does not limit the patent scope of the application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made by using the content of the specification and drawings of the present application, is also included in the patent protection scope of the present application.
Claims
1. A heating control circuit of a heating element, comprising a switching tube electrically connected with the heating element, characterized in that, The heating control circuit further comprises a signal input end and a driving circuit for controlling the on-off of the switch tube, the driving circuit having a first input end, a second input end and an output end connected with the switch tube; The first input end is electrically connected to the signal input end to establish a first signal branch, and the second input end is electrically connected to the signal input end to establish a second signal branch, and a delay circuit is arranged on the second signal branch; The signal input end is configured to receive a heating signal; The delay circuit is configured to output a first delay signal to the second input end when the maintaining time of the heating signal does not exceed a preset delay time, and output a second delay signal to the second input end when the maintaining time of the heating signal exceeds the preset delay time; The driving circuit is configured to control the switch tube to turn on or off based on the heating signal from the first signal branch and the first delay signal from the second signal branch, thereby allowing the heating element to start heating, and control the switch tube to turn off based on the heating signal from the first signal branch and the second delay signal from the second signal branch, thereby prohibiting the heating element to start heating.
2. The heating control circuit of claim 1, wherein, A shaping circuit is further arranged in the second signal branch, the shaping circuit and the delay circuit being sequentially electrically connected between the signal input end and the second input end, and the shaping circuit being configured to shape the heating signal into a high-level signal and deliver it to the delay circuit.
3. The heating control circuit of claim 2, wherein, The shaping circuit comprises a first diode, a first non-inverting Schmitt trigger, a first resistor, a second resistor and a first capacitor; The anode of the first diode is electrically connected to the signal input end, the cathode of the first diode is electrically connected to the input end of the first non-inverting Schmitt trigger, the output end of the first non-inverting Schmitt trigger is electrically connected to the delay circuit, the first resistor is connected in parallel with the first diode, the second resistor is electrically connected between the signal input end and a ground end, and is electrically connected to one end of the first resistor, and the first capacitor is electrically connected between the cathode of the first diode and the ground end, and is electrically connected to the other end of the first resistor.
4. The heating control circuit according to claim 2 or 3, characterized in that, The delay circuit is an RC delay circuit comprising a Schmitt trigger.
5. The heating control circuit of claim 4, wherein, The delay circuit comprises a second diode, an inverting Schmitt trigger, a third resistor and a second capacitor; The cathode of the second diode is electrically connected to the shaping circuit, the anode of the second diode is electrically connected to the input end of the inverting Schmitt trigger, the output end of the inverting Schmitt trigger is electrically connected to the second input end, one end of the third resistor is electrically connected to the cathode of the second diode and the shaping circuit respectively, the other end of the third resistor is electrically connected to the anode of the second diode, the input end of the inverting Schmitt trigger and one end of the second capacitor respectively, and the other end of the second capacitor is grounded.
6. The heating control circuit of claim 5, wherein, The values of the third resistor and the second capacitor satisfy the following formula: V t = E x [1 - exp(-t / R3C2)] wherein V t is a high-level threshold value of the inverting Schmitt trigger, E is a voltage value of the high-level signal, t is a preset delay time, R3 is a resistance value of the third resistor, and C2 is a capacitance value of the second capacitor.
7. The heating control circuit of claim 5, wherein, The driving circuit comprises an NAND gate, and the switch tube comprises a PMOS tube. One input of the NAND gate is the first input and is electrically connected to the signal input, the other input of the NAND gate is the second input and is electrically connected to the output of the inverting Schmitt trigger, the output of the NAND gate is electrically connected to the gate of the PMOS tube, the drain of the PMOS tube is electrically connected to the power supply, and the source of the PMOS tube is connected to the ground through the heat generating element.
8. The heating control circuit of claim 5, wherein, The driving circuit comprises an AND gate, and the switch tube comprises an NMOS tube. One input of the AND gate is the first input and is electrically connected to the signal input, the other input of the AND gate is the second input and is electrically connected to the output of the inverting Schmitt trigger, the output of the AND gate is electrically connected to the gate of the NMOS tube, the drain of the NMOS tube is electrically connected to the power supply through the heat generating element, and the source of the NMOS tube is grounded.
9. The heating control circuit of claim 4, wherein, The delay circuit comprises a third diode, a second non-inverting Schmitt trigger, a fourth resistor and a third capacitor. The cathode of the third diode is electrically connected to the shaping circuit, the anode of the third diode is electrically connected to the input of the second non-inverting Schmitt trigger, the output of the second non-inverting Schmitt trigger is electrically connected to the second input, one end of the fourth resistor is electrically connected to the cathode of the third diode and the shaping circuit respectively, the other end of the fourth resistor is electrically connected to the anode of the third diode, the input of the second non-inverting Schmitt trigger and one end of the third capacitor respectively, and the other end of the third capacitor is grounded.
10. The heating control circuit of claim 9, wherein, The driving circuit comprises a NAND gate, and the switch tube comprises an NMOS tube. One input of the NAND gate is the first input and is electrically connected to the signal input, the other input of the NAND gate is the second input and is electrically connected to the output of the second non-inverting Schmitt trigger, the output of the NAND gate is electrically connected to the gate of the NMOS tube, the drain of the NMOS tube is electrically connected to the power supply through the heat generating element, and the source of the NMOS tube is grounded.
11. An aerosol-generating device comprising: The heating control circuit comprises a controller, a heat generating element and a heating control circuit as claimed in any one of claims 1-10, and the heating control circuit is electrically connected between the controller and the heat generating element.