Protection circuit and aerosol generating device

Abstract

The invention discloses a protection circuit and an aerosol generation device, and the protection circuit receives an input signal through a control module, screens the input signal, and enables the circuit to be normally switched on and work only when the input signal is a high-frequency square wave. When the control end of the switch tube is possibly kept in a fixed level state due to faults such as circuit short circuit, MCU program crash and electrostatic damage, the control module turns off the switch module, so that the circuit cannot continue to work, and serious personal and property safety loss caused by continuous heating of the heating circuit is prevented.

Description

Technical Field

[0001] This invention relates to circuit protection, specifically to a protection circuit and an aerosol generating device. Background Technology

[0002] Aerosol generating devices refer to instruments and equipment that convert solid or liquid substances into suspended particles through physical means. Most existing aerosol generating devices use resistance heating technology. Internally, the heating circuit is turned on and off by a single high or low voltage level driving the switching transistor.

[0003] Because the switching transistor's operation is controlled solely by a single voltage level, the control terminal may remain at a fixed voltage level due to faults such as short circuits, MCU program crashes, or electrostatic discharge, leading to a loss of control over the heating circuit. If the heating circuit malfunctions, the product may continue heating without stopping, potentially causing serious personal injury and property damage. Summary of the Invention

[0004] The main technical problem solved by this invention is the circuit malfunction of existing aerosol generating devices under a fixed input level.

[0005] According to a first aspect, one embodiment provides a protection circuit, comprising:

[0006] Control module and switch module;

[0007] One end of the control module is used to receive an input signal, the input signal including a first signal, and the other end of the control module is connected to the switch module;

[0008] One end of the switch module is used to provide an output signal, and the switch module is used to control the protection circuit to be turned on or off;

[0009] The control module includes:

[0010] A signal filtering unit is provided, the first end of which is used to receive the input signal. The output signal of the switch module includes a first level and a second level. When the input signal is the first signal, the control module turns on the switch module; when the input signal is not the first signal, the control module turns off the switch module.

[0011] A first unidirectional conductive unit, wherein a first end of the first unidirectional conductive unit is connected to a second end of the signal filtering unit, and a second end of the first unidirectional conductive unit is connected to the switching module and ground, and the first unidirectional conductive unit is used to limit the flow of current from the first end of the first unidirectional conductive unit to the second end of the first unidirectional conductive unit.

[0012] In a further embodiment of the present invention, the first unidirectional conductive unit includes a first diode, the cathode of the first diode is connected as the first end of the first unidirectional conductive unit to the second end of the signal filtering unit, and the anode of the first diode is connected as the second end of the first unidirectional conductive unit to the switching module and to ground.

[0013] In a further embodiment of the present invention, the control module further includes:

[0014] A first resistor, the first end of which is used to receive the input signal, and the second end of which is connected to the first end of the signal filtering unit, are used to limit the current applied by the input signal to the control module and the switching module.

[0015] In a further embodiment of the present invention, the switching module includes a first terminal, a second terminal, and a control stage;

[0016] The first end of the switch module is connected to the second end of the first unidirectional conductive unit;

[0017] The second terminal of the switching module is used to provide an output signal, which includes a first level or a second level.

[0018] The control stage of the switch module is connected to the second terminal of the signal filtering unit and to the first terminal of the switch module.

[0019] In a further embodiment of the present invention, the switching module further includes:

[0020] The parasitic capacitance is smaller than the capacitance of the signal filtering unit, such that when the signal filtering unit and the parasitic capacitance are charged, the time for the parasitic capacitance to reach a steady state is shorter than that of the signal filtering unit.

[0021] In a further embodiment of the present invention, the control module further includes:

[0022] A second resistor, the first end of which is connected to the control stage of the switching module, and the second end of which is connected to the first end of the switching module and to ground;

[0023] The second resistor is used to enable the parasitic capacitor to discharge through the second resistor. The resistance value of the second resistor is greater than that of the first resistor, so that when the signal filtering unit and the parasitic capacitor are discharged, the time for the parasitic capacitor to reach a steady state after discharge is longer than that for the signal filtering unit.

[0024] In a further embodiment of the present invention, the control module further includes:

[0025] The second unidirectional conductive unit has a first end connected to the control stage of the switching module and a second end connected to the second end of the signal filtering unit. The second unidirectional conductive unit is used to limit the current flow from the first end of the second unidirectional conductive unit to the second end of the second unidirectional conductive unit.

[0026] In a further embodiment of the present invention, the second unidirectional conductive unit includes a second diode, the cathode of the second diode being connected to the control stage of the switching module as the first end of the second unidirectional conductive unit, and the anode of the second diode being connected to the second end of the signal filtering unit as the second end of the second unidirectional conductive unit.

[0027] In a further embodiment of the present invention, the protection circuit further includes:

[0028] A third resistor, the first end of which is connected to the first end of the switch module and to ground, and the second end of which is connected to the second end of the switch module.

[0029] According to a second aspect, one embodiment provides an aerosol generating apparatus, including the protection circuit described above.

[0030] This application discloses a protection circuit and an aerosol generating device. The control module receives and filters input signals. When the input signal is a first signal (a high-frequency square wave signal), the control module turns on the switch module, causing the output signal to output a first level. When the input signal is not the first signal, the control module turns off the switch module, causing the output signal to output a second level. Simultaneously, a first unidirectional conductive unit limits the current flow from its first end to its second end. Together, these components protect the circuit, ensuring that it only operates normally when the input signal is the first signal, which is typically a high-frequency square wave. If the control terminal of the switch transistor remains at a fixed level due to faults such as short circuits, MCU program crashes, or electrostatic discharge, the control module turns off the switch module, preventing the circuit from continuing to operate and avoiding serious personal injury or property damage caused by continuous heating. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the specific structure of the protection circuit in an embodiment of the present invention.

[0032] The reference numerals in the attached diagram are as follows: 100 control module, 110 signal filtering unit, 120 first unidirectional conductive unit, 130 first resistor, 140 second resistor, 150 second unidirectional conductive unit, 200 switch module, 210 first terminal of switch module, 220 second terminal of switch module, 230 control stage of switch module, 300 third resistor, 400 heating module. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0034] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0035] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0036] Aerosol generating devices refer to instruments and equipment that convert solid or liquid substances into suspended particles through physical means. Most existing aerosol generating devices use resistance heating technology. Internally, the heating circuit is turned on and off by a single high or low voltage level driving the switching transistor.

[0037] In practical applications, relying solely on a single-level control of the switching transistor's operating state can lead to the transistor's control terminal maintaining a fixed level due to faults such as short circuits, MCU program crashes, or electrostatic discharge damage. This can result in the heating circuit losing control. Once the heating circuit malfunctions, the product may continue heating without stopping, causing serious personal injury and property damage.

[0038] Based on this discovery, this invention discloses a protection circuit and an aerosol generating device. The control module receives and filters input signals. When the input signal is a first signal, the control module turns on the switch module, causing the output signal to output a first level. When the input signal is not the first signal, the control module turns off the switch module, causing the output signal to output a second level. Simultaneously, a first unidirectional conductive unit limits the current flow from its first end to its second end. Together, these components protect the circuit, ensuring that it only operates normally when the input signal is the first signal, typically a high-frequency square wave. If the switch control terminal remains at a fixed level due to faults such as short circuits, MCU program crashes, or electrostatic discharge, the control module turns off the switch module, preventing the circuit from continuing to operate and avoiding serious personal injury or property damage caused by continuous heating.

[0039] The concept of the present invention will be explained in detail below through specific embodiments.

[0040] In some embodiments, please refer to Figure 1 , Figure 1 This is a schematic diagram of the protection circuit in an embodiment of the present invention. In some embodiments, the protection circuit is applied to the aerosol generating device. The protection circuit is used to protect the internal circuit of the aerosol generating device, so that when the control terminal of the switching transistor may remain at a fixed level due to faults such as short circuit, MCU program crash, or electrostatic damage, the control module 100 causes the switching module 200 to turn off, so that the circuit cannot continue to work.

[0041] The circuit of the aerosol generating device includes a heating module 400, which supports the aerosol generating device. The protection circuit ensures that the circuit can conduct normally and that the heating module 400 can work stably when the input signal is a high-frequency square wave. When the input signal is not the first signal, in some embodiments, when the control terminal of the switch tube may remain at a fixed level due to faults such as short circuit, MCU program crash, or electrostatic damage, the switch module 200 can be controlled and turned off by the control module 100, so that the heating module 400 cannot continue to work.

[0042] The protection circuit includes a control module 100, one end of which is used to receive an input signal, including a first signal. The function of the control module 100 is to ensure that the circuit can be turned on and operate normally only when the input signal is the first signal. In some embodiments, the first input signal is typically a high-frequency square wave.

[0043] The protection circuit includes a switch module 200, one end of which is connected to the control module 100. The switch module 200 provides an output signal and controls the protection circuit to be turned on or off. When the input signal is the first signal, the switch module 200 can be controlled and turned on by the control module 100, allowing the circuit to operate normally. When the input signal is not the first signal, in some embodiments, if the control terminal of the switch transistor may remain at a fixed level due to faults such as short circuits, MCU program crashes, or electrostatic discharge, the switch module 200 can be controlled and turned off by the control module 100, preventing the circuit from continuing to operate.

[0044] The switch module 200 includes a first terminal 210, a second terminal 220, and a control stage 230. The first terminal 210 of the switch module 200 is connected to the second terminal of the first unidirectional conductive unit 120. The second terminal 220 of the switch module 200 is used to provide an output signal, which includes a first level or a second level. The control stage 230 of the switch module 200 is connected to the second terminal of the signal filtering unit 110 and to the first terminal of the switch module 200. The switch module 200 includes a parasitic capacitance, which has a small capacitance. In some embodiments, the switch module 200 is used to control the conduction and cutoff of the protection circuit. When the input signal is the first signal, the control stage 230 of the switch module 200 obtains a stable high level, the switch module 200 is turned on, and the circuit can be normally turned on and operated. When the input signal is not the first signal, the control stage 230 of the switch module 200 has no effective high level, the switch module 200 can be controlled and turned off by the control module 100, and the circuit cannot continue to operate.

[0045] The control module 100 includes a signal filtering unit 110. In some embodiments, the signal filtering unit 110 is a capacitor, allowing it to be charged and discharged. The capacitance of the signal filtering unit 110 needs to be greater than the parasitic capacitance, so that when both the signal filtering unit 110 and the parasitic capacitance are charged, the time it takes for the parasitic capacitance to reach a steady state is less than that of the signal filtering unit 110. The first terminal of the signal filtering unit 110 is used to receive an input signal, and the output signal includes a first level and a second level. When the input signal is the first signal, the control module 100 turns on the switch module 200, enabling the circuit to conduct and operate normally. When the input signal is not the first signal, the control module 100 turns off the switch module 200, preventing the circuit from continuing to operate.

[0046] The control module 100 includes a first unidirectional conductive unit 120. In some embodiments, the first unidirectional conductive unit 120 includes a first diode. A first end of the first unidirectional conductive unit 120 is connected to a second end of the signal filtering unit 110, and the second end of the first unidirectional conductive unit 120 is connected to the switch module 200 and ground. The first unidirectional conductive unit 120 is used to limit the current flow from the first end to the second end of the first unidirectional conductive unit 120. In some embodiments, when the input signal is a first signal, the signal filtering unit 110 can quickly discharge through the loop formed by the signal filtering unit 110 and the first unidirectional conductive unit 120, preventing the signal filtering unit 110 from saturating due to its inability to release charge after charging. If the signal filtering unit 110 saturates, a constant level state can still drive the switch module 200, causing the signal filtering unit 110 to lose its core function of blocking DC and passing AC, resulting in the failure of the protection mechanism of the protection circuit. Therefore, the first unidirectional conductive unit 120 is a necessary guarantee for the normal operation of the signal filtering unit 110.

[0047] The control module 100 also includes a first resistor 130. A first terminal of the first resistor 130 is used to receive the input signal, and a second terminal of the first resistor 130 is connected to a first terminal of the signal filtering unit 110. The first resistor 130 is used to limit the current applied to the control module 100 and the switching module 200 by the input signal. When the input signal is the first signal, the first resistor 130 can provide a charging path for the signal filtering unit 110 and the switching module 200, and limit the magnitude of the charging current to prevent excessive current from damaging the signal filtering unit 110 and the switching module 200, thus ensuring a stable and controllable charging process.

[0048] The control module 100 also includes a second resistor 140. The first end of the second resistor 140 is connected to the control stage 230 of the switch module 200, and the second end of the second resistor 140 is connected to the first end of the switch module 200 and ground. The second resistor 140 allows the parasitic capacitance to discharge. The resistance of the second resistor 140 is greater than that of the first resistor 130, so that when the signal filtering unit 110 and the parasitic capacitance are discharged, the time for the parasitic capacitance to reach a steady state after discharge is longer than that of the signal filtering unit 110. In some embodiments, the second resistor 140 has a relatively large resistance. When the input signal is a high-frequency square wave and the square wave is at a low level, the parasitic capacitance discharges slowly through the second resistor 140. The discharge speed is slow enough to ensure that the control electrode of the switch module 200 remains at a high level when the input signal square wave is low, until the input signal square wave becomes high and continues to charge the parasitic capacitance. This design ensures that when the input signal is a high-frequency square wave to drive the circuit, the switch module 200 remains continuously conducting, allowing the circuit to operate stably.

[0049] The control module 100 also includes a second unidirectional conductive unit 150. In some embodiments, the second unidirectional conductive unit 150 includes a second diode. The first end of the second unidirectional conductive unit 150 is connected to the control stage 230 of the switching module 200, and the second end of the second unidirectional conductive unit 150 is connected to the second end of the signal filtering unit 110. The second unidirectional conductive unit 150 is used to limit the current flow from the first end of the second unidirectional conductive unit 150 to the second end of the second unidirectional conductive unit 150. The specific function of the second unidirectional conductive unit 150 is to isolate interference and separate two different discharge circuits. In some embodiments, when the high-frequency square wave of the input signal is low, there are two discharge circuits in the circuit. The first discharge circuit is the discharge circuit of the signal filtering unit 110, and the current flows from the signal filtering unit 110 to the first resistor 130. The second discharge circuit is the discharge circuit of the parasitic capacitance, and the current flows from the parasitic capacitance to the second resistor 140. The second unidirectional conductive unit 150 can block the crosstalk between the currents of the two circuits, ensuring that the signal filtering unit 110 discharges completely and the parasitic capacitance discharges slowly and stably, thus avoiding abnormal control electrode levels of the switching module 200 caused by current interference.

[0050] The protection circuit also includes a third resistor 300. The first end of the third resistor 300 is connected to the first end of the switching module 200 and then to ground, while the second end of the third resistor 300 is connected to the second end of the switching module 200. The third resistor 300 is used to limit the drive current of the control electrode of the switching module 200, preventing excessive current from damaging the switching module 200. Simultaneously, by limiting the current, it stabilizes the conduction and cutoff states of the switching module 200, and, in conjunction with the input signal, achieves basic power control of the circuit, complementing the protection logic of the switching module 200.

[0051] In practical applications, when the user uses the aerosol generating device and activates the heating module 400, the protection circuit activates. When the input signal is the first signal, and the square wave is high, the signal filtering unit 110 is charged. Current flows through the first resistor 130 to the signal filtering unit 110 and then to the parasitic capacitance of the switching module 200, forming a charging circuit. Since the capacitance of the parasitic capacitance is much smaller than that of the signal filtering unit 110, it is quickly charged to the power supply voltage, causing the control stage 230 of the switching module 200 to obtain a stable high level, the switching module 200 to conduct, and the heating module 400 to operate normally. When the square wave turns low, the first discharge circuit is the discharge circuit of the signal filtering unit 110. Current flows from the signal filtering unit 110 to the first resistor 130 circuit and discharges rapidly, preventing the signal filtering unit 110 from losing its DC blocking and AC passing function due to charge accumulation and saturation. The second discharge circuit is the discharge circuit of the parasitic capacitance. Current flows from the parasitic capacitance to the second resistor 140. Because the second resistor 140 has a large resistance, the parasitic capacitance discharges much slower than the square wave period. The control stage 230 maintains a high level, the switching module 200 remains on, and the heating module 400 continues to operate stably without interruption of heating during the low-level phase of the square wave. This charging and discharging process repeats continuously as the high-frequency square wave signal cycles. The signal filtering unit 110 charges during the high-level phase and discharges during the low-level phase, never saturating, thus always performing its signal filtering function. The parasitic capacitance of the switching module 200 is slowly discharged through the second resistor 140 to maintain a high level, ensuring the switching module 200 remains on and the heating circuit is always in a safe and controllable operating state, achieving normal heating functionality.

[0052] When the input signal is constant, the protection circuit activates the safety blocking mechanism. If the input is constant high (i.e., the input signal is continuously high), after the signal filtering unit 110 is charged by the first resistor 130, the charge cannot be released through the first unidirectional conductive unit 120 because there is no low-level stage to trigger discharge. Ultimately, the signal filtering unit 110 saturates and fails, losing its DC blocking and AC passing function. At this time, the constant high level is isolated by the signal filtering unit 110 and cannot be transmitted to the control level 230 of the switching module 200. The control level 230 of the switching module 200 has no effective drive signal and remains in the off state, preventing the heating circuit from being connected and completely avoiding the risk of continuous heating. If the input is constant low (i.e., the input signal is continuously low), the signal filtering unit 110 has no charging condition, the parasitic capacitance of the switching module 200 has no charging path, the control level 230 remains low, the switching module 200 remains off, the heating circuit remains disconnected, and accidental heating will not occur.

[0053] This application discloses a protection circuit and an aerosol generating device. The control module 100 receives and filters input signals. The control module 100 turns on the switch module 200, causing the output signal to output a first level. When the input signal is not the first signal, the control module 100 turns off the switch module 200, causing the output signal to output a second level. Simultaneously, a first unidirectional conductive unit 120 limits the current flow from its first end to its second end. Together, these components protect the circuit, ensuring that it can only conduct and operate normally when the input signal is the first signal, which is typically a high-frequency square wave. If the control terminal of the switch tube remains at a fixed level due to faults such as short circuits, MCU program crashes, or electrostatic discharge, the control module 100 turns off the switch module 200, preventing the circuit from continuing to operate and avoiding serious personal injury or property damage caused by continuous heating.

[0054] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A protection circuit, characterized in that, include: Control module and switch module; One end of the control module is used to receive an input signal, the input signal including a first signal, and the other end of the control module is connected to the switch module; One end of the switch module is used to provide an output signal, and the switch module is used to control the protection circuit to be turned on or off; The control module includes: A signal filtering unit is provided, the first end of which is used to receive the input signal. The output signal of the switch module includes a first level and a second level. When the input signal is the first signal, the control module turns on the switch module; when the input signal is not the first signal, the control module turns off the switch module. A first unidirectional conductive unit, wherein a first end of the first unidirectional conductive unit is connected to a second end of the signal filtering unit, and a second end of the first unidirectional conductive unit is connected to the switching module and ground, and the first unidirectional conductive unit is used to limit the flow of current from the first end of the first unidirectional conductive unit to the second end of the first unidirectional conductive unit.

2. The protection circuit as described in claim 1, characterized in that, The first unidirectional conductive unit includes a first diode. The cathode of the first diode serves as the first end of the first unidirectional conductive unit and is connected to the second end of the signal filtering unit. The anode of the first diode serves as the second end of the first unidirectional conductive unit and is connected to the switching module and ground.

3. The protection circuit as described in claim 1, characterized in that, The control module also includes: A first resistor, the first end of which is used to receive the input signal, and the second end of which is connected to the first end of the signal filtering unit, is used to limit the current applied by the input signal to the control module and the switching module.

4. The protection circuit as described in claim 1, characterized in that, The switching module includes a first terminal, a second terminal, and a control stage; The first end of the switch module is connected to the second end of the first unidirectional conductive unit; The second terminal of the switching module is used to provide an output signal, which includes a first level or a second level. The control stage of the switch module is connected to the second terminal of the signal filtering unit and to the first terminal of the switch module.

5. The protection circuit as described in claim 4, characterized in that, The switching module also includes: The parasitic capacitance is smaller than the capacitance of the signal filtering unit, such that when the signal filtering unit and the parasitic capacitance are charged, the time for the parasitic capacitance to reach a steady state after charging is shorter than that of the signal filtering unit.

6. The protection circuit as described in claim 5, characterized in that, The control module also includes: A second resistor, the first end of which is connected to the control stage of the switching module, and the second end of which is connected to the first end of the switching module and to ground; The second resistor is used to enable the parasitic capacitor to discharge through the second resistor. The resistance value of the second resistor is greater than that of the first resistor, so that when the signal filtering unit and the parasitic capacitor are discharged, the time for the parasitic capacitor to reach a steady state after discharge is longer than that for the signal filtering unit.

7. The protection circuit as described in claim 5, characterized in that, The control module also includes: The second unidirectional conductive unit has a first end connected to the control stage of the switching module and a second end connected to the second end of the signal filtering unit. The second unidirectional conductive unit is used to limit the current flow from the first end of the second unidirectional conductive unit to the second end of the second unidirectional conductive unit.

8. The protection circuit as described in claim 7, characterized in that, The second unidirectional conductive unit includes a second diode. The cathode of the second diode serves as the first end of the second unidirectional conductive unit and is connected to the control stage of the switching module. The anode of the second diode serves as the second end of the second unidirectional conductive unit and is connected to the second end of the signal filtering unit.

9. The protection circuit as described in claim 4, characterized in that, Also includes: A third resistor, the first end of which is connected to the first end of the switch module and to ground, and the second end of which is connected to the second end of the switch module.

10. An aerosol generating device, characterized in that, include: The protection circuit as described in any one of claims 1 to 9.

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