An improved aerosol-generating system

Abstract

The present invention relates to an improved aerosol-generating device (100) featuring a constant voltage delivery mechanism to regulate power supplied to a heater (141). The device (100) comprises a constant voltage converter (122), a control unit (121), a heater (141), an energy source (battery) (123), an aerosol-5 generating substrate, and a cartridge (140). Unlike conventional pulse width modulation (PWM) methods that introduce power fluctuations, the invention ensures a steady voltage supply to the heater (141), minimizing thermal stress, enhancing heater (141) lifespan, and optimizing aerosol quality. The control unit (121) dynamically adjusts constant voltage supplied to heater (141) based on the 10 heater's resistance to ensure stable power delivery throughout the heating cycle. This prevents overheating, degradation of the aerosol-generating substrate, and fluctuations in aerosol production.

Description

TITLE OF THE INVENTIONAN IMPROVED AEROSOL-GENERATING SYSTEMFIELD OF INVENTION

[0001] The present invention relates to an aerosol-generating device. More particularly, the present invention relates to a constant voltage delivery system for regulating power to a heater within the aerosol-generating device.CROSS REFERENCE TO RELATED APPLICATIONS

[0002] Applicant claims priority and the benefit of Indian Provisional Patent application 202411015717, filed 01 March 2024 (01-03-2024), said application being hereby incorporated herein in its entirety by reference.BACKGROUND OF INVENTION

[0003] Aerosol-generating devices are commonly used for aerosolization of aerosol-forming substrates, such as aerosol-generating liquids. The aerosolgenerating device consists of a cartridge and a body. The cartridge comprises of a heater, aerosol-generating substrate, condensation chamber, mouthpiece, connector pin (e.g. pogo pin and the like), and space to store the aerosol -generating substrate whereas the body consists of a control unit and battery. The control unit is responsible for controlling the overall function of the aerosol-generating device. In general, control units control the power delivery from the energy source (battery) to the heater by using PWM (pulse width modulation) techniques.

[0004] Most of the known devices are operated based on lithium-ion batteries which can deliver power to the heater safely from 3 to 4.2 Volts. While a 1 Ohm heater is connected to the battery, the battery will deliver the power 17.5 Watts at 4.2V and 9 Watts at 3 V. But to generate the desired aerosol, 5W is sufficient. So, the control unit controls the power delivery to the heater using the pulse width modulation technique to maintain an average power of 5W watts supplied to the heater. The control unit, instead of delivering the constant 5W of power, delivers the average power of 5W to the heater. For example, 5W average power can bedelivered to the heater in different methods such as 10W of peak power at 50% duty cycle, 12.5 Watts of peak power at 40% duty cycle, and 17 Watts of peak power at 30% duty cycle. In all cases, the power given to the heater is more than the desired limit.

[0005] The drawback of average power delivery using PWM technique is that instant power or peak power given to the heater is more than the average power at any point in time. In other words, the average power or the actual power given to the heater is always more than the required power. Operating the heater in an average power delivery mode is undesirable and leads to increased thermal stress to the heater as well as aerosol- generating substrate because of the average power supply. Continuous thermal stress in the heater reduces the overall life cycle of the heater and degrades the aerosol- generating substrate quality and flavor experience to the user. Hence, it is desired to deliver the required constant power to the heater during the operation, so that the thermal stress to the heater as well as aerosolgenerating substrate can be reduced.

[0006] The prior art, US20200352247A, describes a control unit configured to control the conversion unit by applying a constant voltage to the entire circuit to derive the electric resistance value of the load. US’247 employs a mechanism to compare the change in the heater's resistance value during the heating cycle against a stored, predefined value in memory. This comparison calibrates the heater characteristics, and the new value is stored in memory for future reference. As a result, US’247 facilitates liquid depletion detection in the cartridge, dry inhalation prevention, and temperature control.

[0007] The prior art, WO2022239405A1, describes an aerosol -generating device with a charging IC configured to boost the power input from the power supply to the charging terminal to generate high-voltage power and supply it to the first load via the input terminal. WO’405 focuses on the power supply unit, which consists of a charging IC, a power supply (battery), an external power supply, and connectors. WO’405 attempts to boost the power delivery to the battery, whereby the charging IC takes power from the input power supply and modifies (boosts) itto meet the high-power demand of the battery. As a result, WO’405 can reduce the charging time.

[0008] The prior art, US11178911B2, describes a voltage sensor connected in parallel with the load, configured to output a voltage value applied to the load. US’911 further describes a mechanism to determine the voltage across the heater as well as the current through the heater. US’911 further attempted to create a resistance versus temperature profile by using the voltage and current values captured using sensing circuits. This method may be used to estimate the operating temperature of the heater.

[0009] Other general prior-art references in the domain, such as EP2967140B1, describe heating control arrangements using pulse width modulation (PWM), which regulate average power based on cycle periods. However, such techniques introduce unwanted thermal peaks that can cause overheating risks. Similarly, EP4406435A1 introduces a temperature monitoring system but relies on complex closed-loop controls requiring feedback circuits. CN114868977A focuses on heat dissipation and waste heat utilization but does not address the problem of heater thermal stress due to power fluctuations.

[0010] Hence, there exists a need for an improved aerosol -generating system that eliminates the thermal stress associated with PWM methods, enhances heater lifespan, and provides a consistent aerosol production experience.

[0011] The present invention aims to reduce the thermal stress to the heater as well as the aerosol-generating substrate for operating the heater in the constant voltage method. The voltage across the heater will always be constant during the operation.OBJECT OF INVENTION

[0012] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0013] It is an object of the present invention to provide constant power to a heating element (heater), using constant voltage method within the aerosol -generating device.

[0014] It is another object of the present invention to eliminate fluctuations in power output.

[0015] It is yet another object of the present invention to mitigate thermal stress on critical components, including the heater and the aerosol-generating substrate within the aerosol-generating device.

[0016] It is yet another object of the present invention to increase the lifespan of the heater and improve aerosol generation efficiency by minimizing thermal stress and ensuring optimal operating conditions.

[0017] It is yet another object of the present invention to enhance user experience.

[0018] Other obj ects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.SUMMARY OF THE INVENTION

[0019] The present invention discloses a constant voltage delivery system designed specifically for aerosol -generating devices. The present invention comprises a constant voltage converter, a control unit, a heater, an energy source (battery), an aerosol-generating substrate, and a cartridge. Unlike conventional methods that rely on fluctuating power output, the present invention ensures a consistent voltage is supplied to the heating element (heater) throughout the device's operation. By maintaining stable power delivery, the present invention aims to address key issues such as overheating, degradation of the heater, and deterioration of the quality of the aerosol-generating substrate.

[0020] The control unit delivers power to the heater from a constant voltage converter rather than directly from the energy source (battery). In this mechanism, the voltage supplied to the heater is continuous, ensuring no discontinuity in voltagedelivery throughout the heating cycle. Unlike conventional systems using pulse width modulation (PWM) that can cause power fluctuations, the present invention maintains a steady voltage across the heater, preventing temperature spikes. This constant voltage method reduces thermal stress and enhances heater durability. Moreover, the power delivered to the heater will not exceed the desired power.

[0021] The control unit incorporates a constant voltage converter, which modifies the variable voltage supplied by the energy source (battery) to provide a constant voltage across the heater. It draws power from the energy source (battery) and adjusts the voltage based on the heater resistance, ensuring continuous delivery throughout the heating cycle.

[0022] By maintaining a constant voltage across the heater during operation, the degradation of the heater's lifecycle and thermal stress on the aerosol -generating substrate can be minimized. Furthermore, the control unit adjusts the voltage delivered to the heater based on changes in the heater's resistance during the heating cycle.BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0023] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0024] Figure 1 illustrates the structural arrangement of an aerosol -generating device (100) in accordance with one embodiment of the present invention.

[0025] Figure 2 illustrates the fundamental structural arrangement and voltage profile across the heater in the constant voltage method, as described in an embodiment of the present invention.

[0026] Figure 3 illustrates the fundamental structural arrangement and voltage profile across the heater in the pulse width modulation (PWM) method, according to an embodiment of the existing prior art.

[0027] Figure 4 illustrates validation plots comparing bare heater test results obtained using both the constant voltage method and the pulse width modulation (PWM) method.

[0028] Figure 5 illustrates validation plots comparing temperature measurements taken at the heater's side using both the constant voltage method and the pulse width modulation (PWM) method with respect to the operating time of device (100).

[0029] Figure 6 illustrates validation plots comparing the maximum and mean temperature measurements at the bottom of the heater, obtained using both the constant voltage method and the pulse width modulation (PWM) method, with respect to the operating time of device (100).LIST OF REFERENCE NUMERALS100 - Aerosol-generating device120 - Body121 - Control unit122 - Constant voltage converter123 - Energy source (Battery)140 - Cartridge141 - Heater142 - Condensation chamber143 - MouthpieceDETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention may be embodied in several forms, and the details of embodiments of the present invention will be described in the following content with figures. The embodiments described below with reference to the drawings are merely illustrative of the technical solutions of the present disclosure but are not to be construed as limited to the technical solutions of the present disclosure.

[0031] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor toenable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of the present invention is provided for illustration purposes only and not for the purpose of limiting the invention as defined by the appended claims. As used in the description of the invention and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0033] The term “Cartridge” refers to a container that can hold the aerosolgenerating substrate.

[0034] The present invention introduces a series of innovative embodiments for an improved aerosol-generating device. The device is designed to enhance the consistency and efficiency of aerosol generation by ensuring steady and controlled power delivery to the heater, which mitigates performance inconsistencies such as overheating, underheating, and variable aerosol quality. The constant voltage converter plays a crucial role in stabilizing the power supply, converting the fluctuating voltage from the energy source into a steady, constant voltage to optimize the heating process.

[0035] In a preferred embodiment, the present invention discloses an improved aerosol-generating device that ensures efficient and controlled aerosolization of an aerosol-generating substrate through the utilization of a constant voltage regulation mechanism. The device consists of two primary components: a body and a cartridge. The components within the body and cartridge are operably connected toensure electrical communication and transfer control signals, enabling precise control, efficient operation, and user-friendly functionality. The body incorporates essential elements such as a control unit, a constant voltage converter, an energy source (battery), and heater termination connections. The cartridge houses a heater, an aerosol-generating substrate, a condensation chamber, and a mouthpiece for generating and delivering the aerosol. The integration of these components ensures seamless operation and optimal performance, resulting in a device that is both compact and efficient.

[0036] In another embodiment, a key feature of the present invention is the constant voltage converter, which regulates the fluctuating battery voltage, typically ranging from 3.1V to 4.3V depending on the battery charge level. Conventional aerosolgenerating devices utilize pulse width modulation (PWM) to regulate the operating power supplied to the heater, where the heater receives bursts of power interspersed with off-cycles, leading to irregular heating patterns and inconsistent aerosol quality. To overcome this issue, the constant voltage converter modifies the incoming fluctuating voltage into a steady, constant voltage output based on the resistance of the heater. This ensures that the heater receives a constant power supply, thereby maintaining uniform heat distribution across the heating surface, and preventing overheating, thermal stress, degradation, and deterioration of the aerosol-generating substrate quality.

[0037] In yet another embodiment, the invention incorporates a dynamic voltage regulation feature provided by the control unit. The control unit is programmed to monitor the inherent resistance of the heater in real-time and adjust the constant voltage supply accordingly. This adaptive control mechanism allows the device to maintain a consistent heating profile throughout the aerosolization process. As the heater undergoes resistance changes due to prolonged use, the control unit ensures that the constant voltage converter delivers an appropriate and desired constant voltage to sustain efficient and uniform heating. This prevents thermal stress on the heater and significantly extends its lifespan, thereby making the device more durable and reliable over prolonged usage.

[0038] In yet another embodiment, the constant voltage converter ensures uninterrupted power delivery without any on-off cycle interruptions. Many conventional aerosol-generating devices operate through a series of on-and-off cycles, characteristic of pulse width modulation, to average the overall power delivered to the heater, dependent on battery voltage fluctuations. The present invention supplies a constant power flow instead of average power, ensuring that the heater remains active throughout the heating cycle. This guarantees consistent user experience, as the aerosol-generating substrate is aerosolized uniformly without unexpected temperature fluctuations that can affect the quality and intensity of the aerosol generation.

[0039] In yet another embodiment, the present invention features a straightforward and reliable power regulation mechanism facilitated by the control unit and the constant voltage converter. Unlike conventional devices that rely on averaging power delivery over time, which contributes to a more rapid initial increase in temperature, the present invention provides a direct and simplified control mechanism. The control unit continuously regulates power delivery by adjusting the constant voltage applied to the heater based on its real-time resistance changes. This ensures uniform temperature distribution across the heater surface, leading to consistent aerosol generation.

[0040] In yet another embodiment, the control unit in the present invention ensures uninterrupted, steady, and constant voltage power delivery to the heater throughout the heating cycle, preventing both overheating and underheating. The control unit, in conjunction with the constant voltage converter, actively regulates power supply to maintain optimal heating performance. This prevents thermal degradation, ensures consistent aerosol quality, and eliminates fluctuations that could negatively affect aerosol generation device performance.

[0041] In yet another embodiment, the present invention enhances the lifespan of the heater by mitigating overheating and thermal stress. The regulated constant voltage delivery ensures that the heater is not exposed to excessive power levels that could degrade its structure or reduce its efficiency. By maintaining an optimaltemperature with a consistent voltage supply, the invention ensures that the heater performs consistently over an extended period. This also prevents deterioration of the aerosol-generating substrate, ensuring that users consistently experience high- quality aerosol generation without flavor degradation. This feature makes the device suitable for prolonged use, reducing the need for frequent heater replacements.

[0042] In yet another embodiment, the present invention utilizes a constant voltage method to ensure precise and consistent power delivery across the heater throughout the heating cycle. This method begins with the control unit measuring the inherent resistance of the heater both before and during operation. Based on this resistance, the control unit determines the desired constant voltage required for efficient heating and sends a control signal to the constant voltage converter. The constant voltage converter then modifies the fluctuating battery voltage (ranging from 3.1V to 4.3 V, depending on charge levels) into a steady, constant voltage suitable for the heater.

[0043] Throughout the heating cycle, the control unit continuously monitors the variation in heater resistance in real-time due to prolonged use. As resistance changes, the control unit dynamically adjusts the constant voltage output from the converter to maintain a stable power level. This ensures that the heater consistently receives the required power, preventing power interruptions, overheating, or underheating. By preventing fluctuations in heating performance, this method facilitates uniform heating, efficient aerosolization of the aerosol -generating substrate, and enhanced aerosol quality. Furthermore, the regulated power delivery reduces thermal stress, preventing premature degradation of the heater and extending its lifespan. This approach ensures a reliable and efficient heating system for an aerosol-generating device.

[0044] In yet another embodiment, the constant voltage method ensures precise temperature control by dynamically regulating voltage delivery to the heater, thereby minimizing thermal stress and enhancing heater longevity. By maintaining a consistent voltage supply, the method prevents temperature fluctuations, ensuringuniform heat distribution across the heater. This results in consistent heating, optimizing aerosol generation while preventing degradation due to overheating or inefficiencies due to underheating.

[0045] Overall, these embodiments provide an improved aerosol -generating device featuring a control unit with a constant voltage converter that regulates fluctuating battery voltage into a steady, constant power supply for the heater. By continuously monitoring heater resistance in real-time and adjusting voltage output, the device ensures consistent heating performance, preventing overheating, underheating, and thermal stress. This controlled voltage regulation enhances heater lifespan, ensures efficient aerosolization of the aerosol -generating substrate, and maintains consistent aerosol quality. Additionally, uniform heat distribution across the heater minimizes temperature fluctuations, providing precise temperature control and a reliable, uninterrupted heating cycle, resulting in a durable and efficient aerosol - generating device.

[0046] With reference to Figure 1, the improved aerosol-generating device (100) according to the present invention ensures efficient and controlled aerosolization of an aerosol-generating substrate through the utilization of a constant voltage regulation mechanism. The device (100) consists of two primary components: a body (120) and a cartridge (140). The body (120) incorporates essential elements such as a control unit (121), a constant voltage converter (122), and an energy source (battery) (123). The cartridge (140) houses a heater (141), a condensation chamber (142), and a mouthpiece (143) attached at one end. As illustrated, the components within the body (120) and cartridge (140) are operably connected to ensure electrical communication and the transfer of control signals, enabling precise control, efficient operation, and user-friendly functionality.

[0047] With reference to Figures 1 and 2, the body (120) constitutes the bottom portion of the improved aerosol-generating device (100), wherein the energy source (battery) (123) provides the required electrical power to the entire device (100).

[0048] With reference to Figure 1, the cartridge (140) constitutes the top portion of the aerosol-generating device (100), where aerosol is generated by heating the aerosol-generating substrate contained therein. One end of the cartridge (140) is removably attached to the mouthpiece (143), while the opposite end is removably attached to the body (120) and incorporates a leak-proof sleeve to prevent leakage of the aerosol-generating substrate from the cartridge (140) into the body (120).

[0049] With reference to Figures 1 and 2, the control unit (121) within the body (120) incorporates the constant voltage converter (122), a core component of this invention. The constant voltage converter (122) is in electrical communication with both the energy source (battery) (123) and the heater (141). The constant voltage converter (122) receives the fluctuating battery voltage, typically ranging from 3.1V to 4.3V depending on the energy source (battery) (123) charge level, and modifies it into a steady, constant voltage output based on the resistance of the heater (141).

[0050] The control unit (121) is programmed to monitor the inherent resistance of the heater (141) in real-time and adjust the constant voltage supply accordingly. As illustrated in Figure 2, this adaptive control mechanism allows the device (100) to maintain a consistent heating profile throughout the aerosolization process. As the heater (141) experiences resistance changes due to prolonged use or heating cycle, the control unit (121) ensures that the constant voltage converter (122) delivers an appropriate and desired constant voltage to sustain efficient and uniform heating. This prevents thermal stress on the heater (141) and significantly extends its lifespan, thereby enhancing the device's (100) durability and reliability over extended use.

[0051] The control unit (121) determines the desired constant voltage to be delivered across the heater (141) based on Ohm’s Law, which is expressed as:. - V2V = ? x R or P = —Rin this context: V refers to the desired constant voltage delivered across the heater (141), P refers to the optimal power required for the aerosolization process, and R represents the measured value of the inherent resistance of the heater (141) in realtime.

[0052] For example, in a preferred embodiment, if the optimal power for the aerosolization process is set at 5 Watts and the inherent resistance of the heater (141) is measured at 1.15 Ohms, then the desired constant voltage delivered across the heater (141) can be calculated as follows:V = bW x 1.15(1 « 2.4 Volts

[0053] Consequently, the control unit (121) sends a control signal to the constant voltage converter (122) to ensure a steady and constant voltage of 2.4 Volts is delivered to the heater (141). This guarantees a consistent optimal power of 5 Watts to the heater (141), resulting in uninterrupted and uniform heating across the heater surface.

[0054] The optimal power required for the aerosolization process can be adjusted based on user preferences for the aerosol generation quality. A core aspect of this invention is ensuring a constant voltage supply, based on the measured heater resistance, to achieve the user-preferred optimal power across the heater (141).

[0055] With reference to Figure 2, the constant voltage converter (122) ensures uninterrupted power delivery without on-off cycle interruptions to average the desired power delivered to the heater (141). The improved aerosol -generating device (100) supplies a constant power flow instead of average power, ensuring that the heater (141) remains active throughout the heating cycle to avoid temperature fluctuations across the heater surface during the heating cycle.

[0056] The control unit (121) and the constant voltage converter (122) offer a straightforward and reliable power regulation mechanism to avoid a more rapid initial increase in temperature and subsequently reduce it to average out the desired power flow across the heater (141). The control unit (121), through the constantvoltage converter (122), provides consistent power delivery throughout the heating cycle by monitoring resistance variations in the heater (141). This ensures uniform temperature distribution across the heater surface, leading to consistent aerosol generation.

[0057] The control unit (121), in conjunction with the constant voltage converter (122), ensures uninterrupted, steady, and constant voltage power delivery to the heater throughout the heating cycle, preventing both overheating and underheating, thereby maintaining optimal heating performance.

[0058] The improved aerosol -generating device (100) enhances the lifespan of the heater (141) by mitigating overheating and thermal stress. The regulated constant voltage delivery ensures that the heater (141) is not exposed to excessive or deficient power levels attributable to the fluctuating battery voltage. The device (100) maintains an optimal temperature with a consistent voltage supply, thereby ensuring that the heater (141) performs consistently over an extended period.

[0059] The improved aerosol-generating device (100) employs a constant voltage method to ensure precise and consistent power delivery to the heater (141) throughout the heating cycle. Initially, the control unit (121) measures the inherent resistance of the heater (141) both before and during operation. Based on this realtime resistance measurement, the control unit (121) calculates the desired constant voltage necessary for uniform heating and transmits a corresponding control signal to the constant voltage converter (122). The constant voltage converter (122) then transforms the fluctuating battery voltage (typically ranging from 3.1V to 4.3V, depending on charge levels) into a stable, constant voltage suitable for the heater (141).

[0060] All the time during the heating cycle, the control unit (121) continuously monitors any variations in the heater's resistance. As the resistance changes, the control unit (121) dynamically adjusts the constant voltage output from the constant voltage converter (122) to maintain a stable power level at the heater (141) end. This ensures that the heater (141) consistently receives the required power, therebypreventing power interruptions, overheating, or underheating. By mitigating fluctuations in heating performance, this method promotes uniform heating, efficient vaporization of the aerosol-generating substrate, and enhanced aerosol quality.

[0061] The constant voltage method achieves precise temperature control through dynamic regulation of voltage delivery to the heater (141), effectively minimizing thermal stress and prolonging the heater's (141) operational lifespan. By maintaining a consistent voltage supply, the method mitigates temperature fluctuations, ensuring uniform heat distribution across the heater (141).

[0062] The improved aerosol-generating device (100) disclosed herein incorporates a control unit (121) with a constant voltage converter (122) to transform fluctuating battery voltage into a stable, constant power supply for the heater (141). By continuously monitoring heater resistance in real-time and dynamically adjusting voltage output, the device (100) achieves consistent heating performance, which prevents overheating, underheating, and thermal stress. This precise voltage regulation extends the heater's lifespan, ensures efficient aerosolization of the substrate, and maintains consistent aerosol quality. Furthermore, uniform heat distribution across the heater (141) minimizes temperature fluctuations, providing precise temperature control and a reliable, uninterrupted heating cycle, thereby resulting in a durable and efficient aerosolgenerating device (100).

[0063] EXPERIMENTAL VALIDATION

[0064] With reference to Figures 2 - 6, the constant voltage method (present invention) was validated through a comparison of experimental outcomes with those obtained using the pulse width modulation (PWM) method (existing method).

[0065] With reference to Figure 2, the control unit along with the constant voltage converter, is crucial for managing battery power to the heater by using a constant voltage method to ensure a stable voltage, which is essential for maintaining the desired temperature effectively, the control unit regulates power distribution,considering user needs and heater resistance for efficient and safe operation, while the converter handles battery voltages (3.1V-4.3V), converting them into a steady output to prevent overheating or underheating, thus providing a reliable and effective heating solution tailored to user needs.

[0066] With reference to Figure 3, in the existing method, the control unit and MOSFET switch manage power delivery from the energy source (battery) to the heating element using pulse width modulation (PWM) to regulate operating power. PWM adjusts the duty cycle, which is the proportion of time the MOSFET is on, allowing the control unit to fine-tune power delivery based on user preferences, heater resistance, and battery voltage. The battery voltage fluctuates (3.1V-4.3V), resulting in potential peak power outputs (9-18.5W) that are converted to average power via PWM. However, high peak power can cause significant temperature increases and thermal stress on both the heater and the aerosol -generating liquid. Managing these thermal dynamics is crucial for device longevity and maintaining optimal performance.

[0067] With reference to Figure 4, the Bare Heater experimental study analyzes and compares the effects of Constant Voltage method and Pulse Width Modulation (PWM) method on a ceramic heater, focusing on monitoring the heater's temperature rise over a short, 2-second interval without any aerosol-generating liquid present. To ensure a direct comparison of thermal responses, both methods are tested at a consistent 5-watt power input. With Constant Voltage method, a stable voltage is continuously supplied to the ceramic heater, guaranteeing a constant 5-watt power output throughout the testing period, which facilitates an even temperature increase across the heater's surface. In contrast, the PWM method delivers the same average power (5 watts) through a series of on-and-off cycles PWM method adjusts the duty cycle of peak power based on the battery voltage to deliver average power of 5 Watts which causes a rapid initial increase in temperature, characteristic of pulse width modulation. The PWM method regulates the duty cycle of peak power according to the battery voltage, aiming to deliver anaverage power of 5 watts. This adjustment leads to a rapid initial increase in temperature.

[0068] With reference to Figure 5, the experimental study on temperature measurements analyzes the effects of Constant Voltage and Pulse Width Modulation (PWM) on a ceramic heater, monitoring its temperature rise over 2 seconds without aerosol -generating substrate, using a constant 5 -watt input to compare thermal responses. The Constant Voltage method supplies continuous, stable voltage, ensuring a consistent 5-watt output for an even temperature increase. Conversely, PWM delivers 5 watts through on-and-off cycles, resulting in a peak power exceeding the 5-watt average and a more rapid initial temperature increase. Experimental outcomes (reference to Figure 5) indicate that PWM causes a more rapid temperature increase; after 500 milliseconds, the temperature difference between the methods reaches approximately 100°C. This highlights PWM's potential to generate higher thermal stress on the ceramic heater and any aerosolgenerating substrate present. While PWM enhances the initial heating response, it increases the risk of thermal stress due to higher peak power. Constant Voltage offers a more controlled heating environment, allowing precise regulation of temperature rise and thermal stress, which is crucial for applications requiring stable and predictable heating performance.

[0069] With reference to Figure 6, the experimental study on temperature measurements analyzes the pulse width modulation (PWM) method shows a significant temperature difference of approximately 208°C between the maximum recorded temperature and the mean temperature, highlighting the temperature fluctuations inherent in PWM thermal control. In contrast, the constant voltage method demonstrates a slightly reduced temperature difference of 185°C between its maximum and mean temperatures. This analysis indicates that the constant voltage method is more effective in achieving uniform heating, distributing heat more evenly and resulting in less temperature variation. While pulse width modulation method may enable rapid changes in heating, it creates less stable temperature conditions.

[0070] The present invention may take many forms and modifications, and the specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms set forth in the detailed description, but rather to include all modifications and equivalents within the spirit and scope of the invention as defined.

Claims

CLAIMS1. An aerosol -generating device (100), comprising: a body (120) comprising a control unit (121), a constant voltage converter (122), and an energy source (123); a cartridge (140) comprising a heater (141), an aerosol -generating substrate, a condensation chamber (142), and a mouthpiece (143); wherein the constant voltage converter (122) in the control unit (121) regulates the fluctuating voltage from the energy source (123), converting it into a steady, constant voltage for delivery to the heater (141).

2. The aerosol -generating device (100) as claimed in claim 1, wherein the control unit (121) adjusts the desired constant voltage supplied to the heater (141) based on its inherent resistance and real-time variations during the heating cycle.

3. The aerosol -generating device (100) as claimed in claim 1, wherein the constant voltage converter (122) receives fluctuating energy source voltages, depending on the energy source (123) charge level, and converts it into a steady voltage based on the heater resistance before supplying it to the heater (141).

4. The aerosol -generating device (100) as claimed in claim 1, wherein the constant voltage converter (122) ensures a continuous and uninterrupted supply of the desired constant voltage without any interruptions to off- cycles.

5. The aerosol -generating device (100) as claimed in claim 1, wherein the control unit (121) continuously monitors real-time variations in the heater (141) resistance during the heating cycle and dynamically adjusts the constant voltage delivered via the constant voltage converter (122).

6. The improved aerosol-generating device (100) as claimed in claim 1, wherein the control unit (121), through the constant voltage converter (122), provides a consistent power delivery throughout the heating cycle by monitoring resistance variations in the heater (141), ensuring uniform temperature distribution across the heater (141).

7. The aerosol -generating device (100) as claimed in claim 1, wherein the control unit (121) ensures uninterrupted, steady, and constant voltage power delivery to the heater (141) throughout the heating cycle.

8. The aerosol -generating device (100) as claimed in claim 1, wherein the heater (141) consistently receives the desired constant power throughout the heating cycle.

9. The aerosol -generating device as claimed in claim 1, wherein the regulated constant voltage delivery enhances the lifespan of the heater (141) by preventing overheating, thermal stress, degradation, and deterioration of the aerosol-generating substrate quality.

10. A constant voltage method of ensuring constant power delivery across the heater (141) of the improved aerosol-generating device (100), comprising: measuring the inherent resistance of the heater (141) via the control unit (121); determining the desired constant voltage to be delivered across the heater (141) and sending a corresponding control signal to the constant voltage converter (122); receiving fluctuating voltage from the energy source (123) at the constant voltage converter (122), wherein the constant voltage converter (122) stabilizes and regulates the voltage based on the control signal and supplies a steady voltage to the heater (141) for uninterrupted, uniform heating;monitoring resistance variations in the heater (141) in real-time during the heating cycle via the control unit (121) and dynamically adjusting the desired constant voltage accordingly, ensuring consistent power delivery throughout the heating cycle.

11. The constant voltage method as claimed in claim 9, wherein the controlled voltage regulation minimizes thermal stress on the heater (1 1) and allows precise temperature control.

12. The constant voltage method as claimed in claim 9, wherein uniform voltage regulation results in consistent heat distribution, reducing temperature fluctuations and ensuring uniform heating across the heater (141).

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