FIELD
[0001] The present disclosure relates to an aerosol generating apparatus and to a method
of controlling the power supply of an aerosol generating apparatus.
BACKGROUND
[0002] A typical aerosol generating apparatus may comprise a power supply, an aerosol generating
unit that is driven by the power supply, an aerosol precursor, which in use is aerosolised
by the aerosol generating unit to generate an aerosol, and a delivery system for delivery
of the aerosol to a user. Typically, the aerosol generating unit includes a heater
which is driven by the power supply to generate the aerosol.
[0003] There are a number of different categories of aerosol generating apparatus including
heated tobacco ("HT" or "heat not burn" - "HNB") apparatuses, in which the aerosol
precursor is a solid substrate such as tobacco, and "vaping" apparatuses, in which
the aerosol precursor is a vaporisable liquid, typically referred to (and referred
to herein) as "e-liquid".
[0004] In both types of system the heater must be heated to a high enough temperature to
generate an aerosol having particularly desired characteristics. However, this requires
a significant amount of power from the power supply. Therefore, when the system is
powered by a finite power source, such as a battery, the power drawn by the heater
can have a significant effect on the length of time the apparatus is able to operate
before the power source needs to be recharged. Accordingly, a drawback with known
aerosol generating apparatuses is the limited operation length of the apparatus owing
to the power draw of the heater.
[0005] HT apparatuses generally provide continuous heating of the aerosol precursor, including
between puffs. Accordingly, the capacity of HT apparatuses to deliver multiple heating
cycles is limited since the heater is continuously drawing power and the aerosol precursor
is being exhausted, even when the user is not using the apparatus.
[0006] In spite of the effort already invested in the development of aerosol generating
apparatuses/systems, further improvements are desirable.
SUMMARY
[0007] Broadly, the present invention provides an aerosol generating apparatus which is
configured to reduce power consumption by adjusting a power supply to the heater according
to a power profile which is tailored to how a specific user uses the aerosol generating
apparatus. This enables the apparatus to be operated in a more power-efficient manner
by predicting periods of inactivity when the heater does not need to operate at peak
power.
[0008] Accordingly, in a first aspect of the present invention there is provided an aerosol
generating apparatus, comprising a controller operatively connected to a heater, the
heater being configured to heat, according to a power profile, an aerosol precursor
provided in a consumable, wherein the controller is configured to:
measure usage data relating to a user operation of the aerosol generating apparatus
during one or more initial consumable heating cycles;
determine the power profile for the heater based on the usage data; and apply the
power profile to the heater during a subsequent consumable heating cycle.
[0009] Advantageously, by applying a power profile to the heater based on data relating
to an initial (i.e., previous) consumable heating cycle, periods of inactivity, where
the apparatus is not being inhaled from, may be predicted based on past user behaviours.
Accordingly, the power supply to the heater may be reduced during periods of inactivity
thereby increasing the power efficiency of the apparatus and increasing the battery
lifetime.
[0010] Additionally, the power profile being based on the usage data measured during a consumable
heating cycle can enable periods of activity, such as a user inhaling from the apparatus,
to be predicted more accurately. For example, the power supply to the heater may be
increased in preparation for an inhalation or reduced when no inhalation is predicted.
Therefore, the apparatus can be more power efficient than apparatuses which do not
determine data relating to a previous cycle, because the heater can reduce its power
consumption for a longer time between inhalations and increase its temperature more
slowly prior to inhalations thereby decreasing the overall power consumption of the
aerosol generating apparatus.
[0011] In this way, the power profile for the heater may be tailored to a specific user
of the apparatus, thereby optimising the operation of the apparatus for that user
and extending the operation life of the apparatus without detracting from the user
experience of the apparatus.
[0012] The aerosol generating apparatus may be configured for engagement with (i.e. the
consumable may be in the form of) a heated tobacco (HT) consumable. In this respect,
the aerosol generating apparatus may be referred to as a heat-not-burn (HNB) aerosol
generating apparatus or a heated tobacco aerosol generating apparatus. The terms "heated
tobacco" and "heat-not-burn" are used interchangeably herein to describe a consumable
that is of the type that is heated rather than combusted (or are used interchangeably
to describe an aerosol generating apparatus for use with such a consumable). In some
HT systems, the substrate does not include tobacco. For example, the substrate may
be formed with an alternative source of cellulose substrate, with added nicotine,
flavour, and/or aerosol precursor.
[0013] The aerosol precursor may comprise a solid substrate. For example, the solid substrate
may comprise tobacco.
[0014] The controller (which may also be referred to herein as a processor) may form part
of a control unit which is configured to control one or more functions of the aerosol
generation apparatus. The controller may be a microcontroller which is mounted on
a printed circuit board (PCB).
[0015] The control unit may also comprise a memory, e.g. non-volatile memory, which is in
communication with the controller. The memory may include instructions, which, when
implemented, cause the controller to perform certain tasks or steps of a method.
[0016] A consumable heating cycle, which may be referred to herein as a heating session
or a consumable cycle, may be defined as a period during which the heater is activated
for producing an aerosol from an aerosol precursor contained in one particular consumable
or cartridge. The consumable heating cycle may be considered to have ended when the
aerosol precursor is exhausted. When a new consumable is detected, or when a user
exhausts the aerosol precursor and replaces the consumable, the user may initiate
a new consumable heating cycle. In some examples a consumable heating cycle may be
defined as the time between activation of the heater (e.g. by a user) and deactivation
of the heater (e.g. by a user or a controller of the apparatus).
[0017] A consumable heating cycle may be limited to a predetermined period of time associated
with a consumable. For example, the period of time may be determined based on how
long the consumable can be heated for in a heating session before the aerosol precursor
is exhausted. The controller may be configured to monitor an elapsed duration of a
current consumable cycle and terminate the current consumable cycle when the elapsed
duration has exceeded the predetermined period of time associated with that consumable.
[0018] For example, a consumable heating cycle may be at least 1 minute, more preferably
at least 3 minutes, more preferably at least 5 minutes long.
[0019] The controller may be configured to detect the presence of a new consumable in the
apparatus. Therefore the subsequent consumable heating cycle may be determined to
have begun when a new consumable is detected.
[0020] The power profile may comprise information relating to power settings for the heater
and time periods for applying those power settings to the heater. For example, determining
the power profile may comprise determining a low power duration for operating the
heater in a low power setting between inhalations (i.e., puffs) from the aerosol generating
apparatus, the heater being operated in a high power setting during the inhalations.
This duration may also be referred to herein as a "deadtime" or a "standby period"
since it refers to a period between inhalations where the heater is not required to
heat the aerosol precursor to a temperature suitable for generating an aerosol.
[0021] The heater may be operated at a low power setting for a low power duration which
is determined by the controller. The heater temperature may be increased to a higher
temperature which is closer to an operational temperature for generating the aerosol
before a user inhales from the apparatus.
[0022] Therefore, the aerosol may be generated more quickly in response to an inhalation
being detected compared to apparatuses in which the heater may only be activated in
response to detecting an inhalation.
[0023] Applying the power profile to the heater may comprise detecting inhalations (also
referred to as "puffs") from the aerosol generating apparatus and adjusting the supply
of power to the heater (or the power consumption of the heater, or a setting of the
heater) in-between inhalations to a low power setting.
[0024] The magnitude of the adjustment and/or the duration for which the low power setting
is maintained may be defined by the power profile. An expected duration between inhalations
may be predicted based on the usage data measured during the one or more initial consumable
heating cycles. The expected duration may be used to determine a minimum low power
duration for maintaining the heater in the low power setting after an inhalation.
[0025] Reducing the temperature of the heater (e.g., by adjusting the power to the heater)
during the standby periods between puffs can increase the overall power efficiency
of the apparatus. However, there is a risk that the heater will not be at a suitable
temperature for generating aerosol when the user next inhales from the apparatus.
Therefore, by determining the power profile based on usage data measured during the
one or more initial consumable heating cycles, this risk is reduced because the power
profile may be able to more accurately predict when a user might next inhale from
the apparatus. Accordingly, the overall power consumption of the apparatus may be
reduced without detriment (or with minimal detriment) to the user experience of the
apparatus.
[0026] As discussed in detail below, adjusting the power consumption of the heater may include
adjusting a temperature of the heater to a target temperature. For example, the controller
may be configured to reduce the temperature of the heater from the first temperature
to a second (standby) temperature in-between inhalations, wherein the low power setting
for the heater mentioned above corresponds to the operation of the heater when the
heater is at the second temperature. Similarly, the high power setting for the heater
mentioned above can correspond to the operation of the heater when the heater is at
the first temperature. Accordingly, the power profile may be a temperature profile
for the heater.
[0027] More specifically, applying the power profile to the heater may comprise reducing
the temperature of the heater from the first temperature to the second temperature
after an inhalation. For example, the controller may be configured to detect inhalations
from the aerosol generating apparatus during the subsequent consumable heating cycle,
and adjust the power supply to the heater upon, or subsequent to, detecting the end
of an inhalation such that the temperature of the heater is reduced from the first
temperature to the second temperature.
[0028] The controller may be configured to adjust the temperature of the heater by restricting
the power supply to the heater (e.g. partly reducing or fully preventing the supply
of power to the heater). For example, the controller may be configured to apply pulse
width modulation to the power supply to the heater, and the reduction in temperature
may be performed by reducing the duty cycle of the power supply to the heater.
[0029] The first temperature may be an aerosol generating temperature for generating an
aerosol from the aerosol former that has desired characteristics (for inhalation).
The first temperature may, for example, be between 330°C and 360°C. The first temperature
may be between 340°C and 350°C, and may be about 345°C.
[0030] The second temperature may be higher than an ambient temperature of the aerosol generation
apparatus. That is, the heater may be configured to continuously heat the aerosol
precursor, even between puffs. Therefore, the temperature of the aerosol precursor
may be increased more quickly during a puff than if the heater were configured to
be deactivated between puffs. This is particularly useful for HT apparatuses with
a solid aerosol forming substrate which may be slower to heat than liquid precursors.
[0031] The second temperature may be above 50°C, or above 100°C. The second temperature
may be less than 300°C, or less than 275°C, or less than 250°C, or less than 200°C,
or less than 150°C, or less than 100°C. The second temperature may be below a minimum
temperature for generating an aerosol from the aerosol former.
[0032] In some embodiments, the second temperature may be equal to or greater than 5°C lower
than the first temperature. The second temperature may be more than 20°C lower than
the first temperature, or more than 50°C lower, or more than 100°C lower.
[0033] The controller may be configured to reduce the temperature of the heater from the
first temperature to the second temperature immediately following the end of an inhalation.
A time between the end of the inhalation and the (i.e. start of the) reduction in
temperature may be less than 3 seconds, or less than 2 seconds, or less than 1 second.
[0034] The controller may be configured to maintain the heater at the second temperature
for a low temperature duration. The low temperature duration may be defined by the
power profile for the heater. For example, determining the power profile for the heater
may comprise determining a low temperature duration for maintaining the heater at
the second temperature. Therefore, the low temperature duration may be based on the
usage data measured during the one or more initial consumable heating cycles of the
apparatus.
[0035] The controller may be configured to increase the temperature of the heater to the
first temperature after the low temperature duration has elapsed. Therefore, the heater
may be at a suitable temperature for producing an aerosol when the user next inhales
from the apparatus.
[0036] In other examples, the controller may be configured to increase the temperature of
the heater to a third temperature after the low temperature duration has elapsed.
The third temperature may be lower than the first temperature (i.e. between the first
and second temperatures).
[0037] The third temperature may be lower than an aerosol generating temperature. In other
words, the third temperature may not be suitable for generating an aerosol (or at
least generating an aerosol having desired characteristics) from the aerosol former.
Alternatively, the third temperature may be an aerosol generating temperature (but
may e.g. not be an optimal temperature for generating an aerosol having desired characteristics).
[0038] The third temperature may be less than 330°C, or less than 300°C, or less than 250°C,
or less than 200°C. The third temperature may be greater than 100°C, or greater than
200°C, or greater than 250°C, or greater than 300°C.
[0039] The third temperature may be referred to as a priming temperature. Thus, the third
temperature may be such that the power supply is capable of heating the heater from
the third temperature to the first temperature in less than 2 seconds, or e.g. less
than 1 second. In this way, the delay in temperature increase may be imperceptible
to a user.
[0040] The controller may be configured to increase the temperature of the heater from the
third temperature to the first temperature upon detection of an inhalation from the
apparatus.
[0041] The aerosol generating apparatus may comprise a sensor. The aerosol generating apparatus
may comprise a puff sensor (e.g. airflow sensor) for detecting inhalations. The puff
sensor may be a pressure sensor or an acoustic sensor. The puff sensor may be configured
to detect a user puffing (i.e. inhaling) from the aerosol generating apparatus (or
from an aerosol-forming article engaged with the aerosol generating apparatus). The
puff sensor may be configured to produce a signal indicative of a puff state. The
puff sensor may be configured to produce a signal indicative of a characteristic of
the puff (e.g. flow rate, length of time, etc.). The puff sensor may be configured
to produce a signal indicative of the start and/or end of a puff.
[0042] Accordingly, the controller may be configured to reduce the temperature of the heater
from the first temperature to the second temperature in response to a signal from
the puff sensor indicative of the end of a puff.
[0043] The aerosol generating apparatus may comprise a temperature sensor for measuring
a temperature of the heater. Additionally or alternatively, the aerosol generating
apparatus (e.g. the controller) may be configured to determine the temperature of
the heater. For example, the aerosol generating apparatus maybe configured to determine
the temperature of the heater based on an electrical resistance of the heater.
[0044] Accordingly, the controller may be configured to control the temperature of the heater
based on a measured temperature from the temperature sensor or from resistance of
the heater. Reducing and/or increasing the temperature of the heater to a particular
desired temperature (e.g. first, second, or third temperature) may thus comprise altering
the power supply to the heater to reduce/increase the temperature until the measured
temperature passes (e.g. exceeds or falls below) the desired temperature. To achieve
this, the controller may thus compare the measured temperatures with the desired (first,
second or third) temperature.
[0045] Maintaining the temperature at the second temperature may comprise maintaining the
temperature within a temperature range that includes the second temperature (i.e.
but having upper and lower limits that are close to the second temperature).
[0046] The controller may be configured to apply pulse width modulation to the power supply.
In this example, applying the power profile to the heater may comprise adjusting the
duty cycle of the power supply. In other examples, the controller may be configured
to adjust the power supply to the heater by modifying a current or a voltage of the
heater. In other examples, the controller may be configured to adjust a target temperature
of the heater such that the heater draws more or less power from the power supply
depending on the target temperature.
[0047] Applying the power profile may comprise repeating the temperature reduction and temperature
maintenance following each puff (inhalation) in a series of at least two puffs. The
controller may be configured to repeat the temperature reduction and temperature maintenance
for each puff in a consumable heating cycle.
[0048] The one or more initial consumable heating cycles (which may be referred to as a
previous consumable cycle(s)) may be one or more most recent consumable heating cycle
of the aerosol generating apparatus. In other examples, the one or more initial consumable
heating cycle may be one or more previous consumable heating cycles associated with
a particular consumable inserted in the device or with a particular user of the device.
Therefore, the usage data collected during the initial consumable heating cycle(s)
may be referred to as historical usage data relating to one or more previous consumable
heating cycles.
[0049] The one or more initial consumable heating cycles may be a plurality of previous
consumable heating cycles. That is, the controller may be configured to measure data
relating to a plurality of consumable heating cycles. For example, the plurality of
consumable heating cycles may comprise a predetermined number of the most recent previous
consumable cycles. By collecting data for a plurality of consumable cycles, a more
accurate representation of user behaviour may be accumulated thereby increasing the
effectiveness of the power profile at increasing power efficiency for that particular
user.
[0050] The predetermined number of previous consumable cycles may include between two and
ten, more preferably between three and eight, more preferably six of the most recent
consumable heating cycles. The present inventors have found that this number of consumable
heating cycles is desirable for representing an accurate picture of user behaviour
when they are using the aerosol generating apparatus while also enabling the power
profile to be adapted to changing user behaviours.
[0051] The usage data measured during to the one or more initial consumable heating cycles
may comprise information relating to how the apparatus has been used in the one or
more consumable heating cycles. The usage data may comprise one or more of: a frequency
of inhalations from the apparatus, durations measured between inhalations, the shortest
and/or longest durations recorded between inhalations, an average duration measured
between inhalations, etc. The usage data may also include information relating to
device settings during the one or more initial consumable heating cycles. For example,
the usage data may comprise one or more of: a user identity, or a type of consumable,
or a device mode used during the consumable heating cycle (e.g., a lower or higher
temperature -mode).
[0052] Measuring the usage data may comprise detecting inhalations from the aerosol generating
apparatus during the one or more initial consumable heating cycles and measuring elapsed
time periods between consecutive inhalations. The elapsed time periods between consecutive
inhalations may also be referred herein to as historical durations between inhalations.
[0053] When the power profile for the heater comprises a low temperature duration for maintaining
the heater at the second temperature after an inhalation, the low temperature duration
may be calculated based on the elapsed time periods measured during the one or more
initial consumable heating cycles.
[0054] The controller may be configured to determine a shortest elapsed time period between
inhalations during the one or more initial consumable heating cycles. In this example,
the controller may be configured to set the low power duration to the shorted elapsed
time period from the one or more initial consumable heating cycles. The shortest elapsed
time period may give an indication of how soon the user might be expected to inhale
from the apparatus again after a previous inhalation. Therefore, the apparatus can
usefully maintain the heater at the second temperature for the shorted elapsed time
period, thereby reducing power consumption and increasing the temperature of the heater
in preparation for a subsequent inhalation.
[0055] In examples where the usage data is collected for a plurality of initial consumable
heating cycles, the controller may be configured to calculate an average shortest
time period measured between inhalations for each of the plurality of consumable heating
cycles. Therefore, the low temperature duration may be based on the average shortest
time period between inhalations. The low temperature duration may be set to the calculated
average shortest duration between inhalations.
[0056] For example, the low temperature duration may be calculated according to:

where
Tduration is the low temperature duration, N is the number of previous consumable heating cycles,
and
min(
ti) is the shortest measured duration between inhalations for each, nth, consumable
heating cycle.
[0057] The controller may be configured to measure additional usage data during the subsequent
consumable cycle; and update the power profile for the heater based on the additional
usage data. For example, the low temperature duration may be updated for each new
consumable cycle based on the additional usage data.
[0058] The average of the shortest elapsed time periods between inhalations may be a rolling
average of the shortest time periods from the most recent (n) consumable heating cycles.
The rolling average may be updated after the subsequent consumable heating cycle.
By updating the power profile after each cycle, changes in user behaviour of the apparatus
may be reflected in the resulting power profile for the heater thereby ensuring that
the heater is more likely to be a suitable temperature when the user inhales whilst
still improving the power efficiency of the apparatus.
[0059] The controller may be configured to interrupt the low temperature duration upon detection
of a second inhalation and return the heater to the first temperature for producing
the aerosol. Therefore, if the second inhalation is detected before the low temperature
duration following the end of the first inhalation has elapsed, then the heater will
be triggered to heat up and generate the aerosol without waiting for the remainder
of the low temperature duration to elapse.
[0060] The controller may be configured to update the low temperature duration for maintaining
the heater at the second temperature if a user inhales from the apparatus before the
low temperature duration has elapsed. In other words, the controller may be configured
to detect a first inhalation during the subsequent consumable heating cycle, detect
a second, consecutive, inhalation during the subsequent consumable heating cycle,
and, if the second inhalation is detected before the low temperature duration following
the end of the first inhalation has elapsed, determine a new value for the low temperature
duration based on an elapsed duration between the first inhalation and the second
inhalation. By updating the low power duration, the apparatus can adapt to changes
in user behaviour.
[0061] In some examples, the controller may be configured to turn off the heater (and optionally
the aerosol generating apparatus) if a second inhalation is not detected after a predetermined
period of time. Therefore, the apparatus need not continue consuming battery power
by maintaining the heater at the first temperature if the user does not take another
puff.
[0062] The controller may be configured to determine an initial power profile for the heater
for a first consumable heating cycle of the apparatus. The initial power profile may
be a predetermined power profile stored in a memory of the apparatus. For example,
the initial power profile may include a predetermined initial low temperature duration
for maintaining the heater in the low power setting (i.e., at the second temperature)
during the first consumable heating cycle. For example, the predetermined initial
low temperature duration may be between 0.5 seconds and 10 seconds, more preferably
between 0.5 second and 7 seconds, more preferably about 5 seconds.
[0063] As mentioned above, the initial power profile may be retrieved from memory. In some
examples, the initial power profile may be based on device settings of the apparatus.
For example, the user may select a mode of the device indicating how frequently they
wish to inhale.
[0064] In some examples, the controller may be configured to reset the power profile to
the initial power profile in a subsequent consumable heating cycle. For example, the
user may reset the power profile (and hence the low temperature duration) using a
button provided on the apparatus or by using an application on a smart phone. This
may be useful, for example, if the apparatus is being given to a new user. The power
profile for the heater may then be re-tailored to suit the new user.
[0065] The aerosol generating apparatus may comprise a user interface for receipt of a user
input. The controller may be configured to store and/or update a parameter value in
the memory based on a user input received via the user interface. The parameter value
may e.g. be representative of the predetermined time period and/or second temperature.
[0066] The heater may comprise a heating element may be in the form of a rod that extends
from a body of the aerosol generating apparatus. The heating element may extend from
an end of the body that is configured for engagement with the aerosol-forming article.
[0067] In a second aspect of the present invention there is provided a method of controlling
the power supply of an aerosol generating apparatus having a heater configured to
heat an aerosol precursor provided in a consumable, the method comprising: measuring
usage data relating to a user operation of the aerosol generating apparatus during
one or more initial consumable heating cycles; determining a power profile for the
heater based on the usage data; and applying the power profile to the heater during
a subsequent consumable heating cycle.
[0068] The method may be performed using the aerosol generating apparatus according to the
first aspect. Thus the method may be performed by the controller which is operatively
connected to the heater. The controller may be configured to perform each method step
or function described herein.
[0069] The aerosol generating apparatus may comprise a memory. The memory may be e.g. non-volatile
memory. The memory may include instructions, which, when implemented, may cause the
controller to perform certain tasks or steps of the second aspect.
[0070] The memory may be configured to store one or more parameters (e.g. the predetermined
time period and/or the second temperature). The controller may be configured to retrieve
one or more parameters from the memory and control the heater based on a value of
the parameter. For example, the controller may be configured to retrieve a stored
predetermined time period value from the memory and control the heater so as to have
a low power duration dictated by the stored predetermined time period value. Similarly,
the controller may be configured to retrieve a stored second temperature value from
the memory and control the heater so as to have a second temperature dictated by the
stored second temperature value.
[0071] According to an additional aspect, there is provided a method of using the apparatus
according to the first aspect, the method comprising inserting a consumable comprising
an aerosol forming precursor article into the apparatus; and heating the precursor
using the heater.
[0072] In some embodiments, the method may comprise inserting the consumable into a cavity
within a body of the apparatus and penetrating the consumable with a heating element
of the heater upon insertion of the consumable.
[0073] The present disclosure may provide electrical circuitry and/or a computer program
configured to cause an aerosol generating apparatus/system to perform any method or
method step disclosed herein. A computer-readable medium comprising the computer program
is also disclosed.
[0074] In a further aspect of the present invention there is provided a computer-readable
memory comprising instructions which when executed perform the method of the second
aspect.
[0075] For the avoidance of doubt, it would be clear to the skilled person that the apparatus
of the present aspect may include any features described herein for any other aspect
of this disclosure.
[0076] In a further aspect of the present invention, there is provided a system (e.g. a
smoking substitute system) comprising a smoking substitute apparatus according to
the first aspect and an HNB consumable. The HNB consumable may comprise an aerosol-forming
substrate at an upstream end of the HNB consumable. The HNB consumable may be in the
form of a smoking substitute article, e.g. heated tobacco (HT) consumable (also known
as a heat-not- burn (HNB) consumable).
[0077] The preceding summary is provided for purposes of summarizing some examples to provide
a basic understanding of aspects of the subject matter described herein. Accordingly,
the above-described features should not be construed to narrow the scope or spirit
of the subject matter described herein in any way. Moreover, the above and/or proceeding
examples may be combined in any suitable combination to provide further examples,
except where such a combination is clearly impermissible or expressly avoided. Other
features, aspects, and advantages of the subject matter described herein will become
apparent from the following text and the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0078] Aspects, features, and advantages of the present disclosure will become apparent
from the following description of examples in reference to the appended drawings in
which like numerals denote like elements.
Fig. 1 is a block system diagram showing an example aerosol generating apparatus.
Fig. 2 is a block system diagram showing an example implementation of the apparatus of Fig.
1, where the aerosol generating apparatus is configured to generate aerosol from a
solid precursor.
Fig. 3 is a schematic diagram showing an example implementation of the apparatus of Fig.
2.
Fig. 4 is a flowchart illustrating a method of controlling a power supply of an aerosol
generating apparatus according to aspects of the present invention.
Fig. 5 is a flowchart illustrating a method of updating a power profile for a heater of
an aerosol generating apparatus according to aspects of the present invention;
Fig. 6 is a flowchart illustrating a method of controlling a heater of an aerosol generating
apparatus according to aspects of the present invention; and
Fig. 7 is a chart depicting the temperature of a heater, controlled according to the method
of Fig. 6.
DETAILED DESCRIPTION OF EMBODIMENTS
[0079] Before describing several examples implementing the present disclosure, it is to
be understood that the present disclosure is not limited by specific construction
details or process steps set forth in the following description and accompanying drawings.
Rather, it will be apparent to those skilled in the art having the benefit of the
present disclosure that the systems, apparatuses and/or methods described herein could
be embodied differently and/or be practiced or carried out in various alternative
ways.
[0080] Unless otherwise defined herein, scientific, and technical terms used in connection
with the presently disclosed inventive concept(s) shall have the meanings that are
commonly understood by those of ordinary skill in the art and known techniques and
procedures may be performed according to conventional methods well known in the art
and as described in various general and more specific references that may be cited
and discussed in the present specification.
[0081] Any patents, published patent applications, and non-patent publications mentioned
in the specification are hereby incorporated by reference in their entirety.
[0082] All examples implementing the present disclosure can be made and executed without
undue experimentation in light of the present disclosure. While particular examples
have been described, it will be apparent to those of skill in the art that variations
may be applied to the systems, apparatus, and/or methods and in the steps or in the
sequence of steps of the methods described herein without departing from the concept,
spirit, and scope of the inventive concept(s). All such similar substitutions and
modifications apparent to those skilled in the art are deemed to be within the spirit,
scope, and concept of the inventive concept(s) as defined by the appended claims.
[0083] The use of the term "a" or "an" in the claims and/or the specification may mean "one,"
as well as "one or more," "at least one," and "one or more than one." As such, the
terms "a," "an," and "the," as well as all singular terms, include plural referents
unless the context clearly indicates otherwise. Likewise, plural terms shall include
the singular unless otherwise required by context.
[0084] The use of the term "or" in the present disclosure (including the claims) is used
to mean an inclusive "and/or" unless explicitly indicated to refer to alternatives
only or unless the alternatives are mutually exclusive. For example, a condition "A
or B" is satisfied by any of the following: A is true (or present), and B is false
(or not present), A is false (or not present), and B is true (or present), and both
A and B are true (or present).
[0085] As used in this specification and claim(s), the words "comprising, "having," "including,"
or "containing" (and any forms thereof, such as "comprise" and "comprises," "have"
and "has," "includes" and "include," or "contains" and "contain," respectively) are
inclusive or open-ended and do not exclude additional, unrecited elements or method
steps.
[0086] Unless otherwise explicitly stated as incompatible, or the physics or otherwise of
the embodiments, examples, or claims prevent such a combination, the features of examples
disclosed herein, and of the claims, may be integrated together in any suitable arrangement,
especially ones where there is a beneficial effect in doing so. This is not limited
to only any specified benefit, and instead may arise from an "ex post facto" benefit.
This is to say that the combination of features is not limited by the described forms,
particularly the form (e.g. numbering) of example(s), embodiment(s), or dependency
of claim(s). Moreover, this also applies to the phrase "in one embodiment," "according
to an embodiment," and the like, which are merely a stylistic form of wording and
are not to be construed as limiting the following features to a separate embodiment
to all other instances of the same or similar wording. This is to say, a reference
to 'an,' 'one,' or 'some' embodiment(s) may be a reference to any one or more, and/or
all embodiments, or combination(s) thereof, disclosed. Also, similarly, the reference
to "the" embodiment may not be limited to the immediately preceding embodiment. Further,
all references to one or more embodiments or examples are to be construed as non-limiting
to the claims.
[0087] The present disclosure may be better understood in view of the following explanations,
wherein the terms used that are separated by "or" may be used interchangeably:
As used herein, an
"aerosol generating apparatus" (or "
electronic(e)-cigarette") may be an apparatus configured to deliver an aerosol to a user for inhalation by
the user. The apparatus may additionally/alternatively be referred to as a "smoking
substitute apparatus", if it is intended to be used instead of a conventional combustible
smoking article. As used herein a combustible "smoking article" may refer to a cigarette,
cigar, pipe, or other article, that produces smoke (an aerosol comprising solid particulates
and gas) via heating above the thermal decomposition temperature (typically by combustion
and/or pyrolysis). An aerosol generated by the apparatus may comprise an aerosol with
particle sizes of 0.2 - 7 microns, or less than 10 microns, or less than 7 microns.
This particle size may be achieved by control of one or more of: heater temperature;
cooling rate as the vapour condenses to an aerosol; flow properties including turbulence
and velocity. The generation of aerosol by the aerosol generating apparatus may be
controlled by an input device. The input device may be configured to be user-activated
and may for example include or take the form of an actuator (e.g. actuation button)
and/or an airflow sensor.
[0088] Each occurrence of the aerosol generating apparatus being caused to generate aerosol
for a period of time (which may be variable) may be referred to as an
"activation" of the aerosol generating apparatus. The aerosol generating apparatus may be arranged
to allow an amount of aerosol delivered to a user to be varied per activation (as
opposed to delivering a fixed dose of aerosol), e.g. by activating an aerosol generating
unit of the apparatus for a variable amount of time, e.g. based on the strength/duration
of a draw of a user through a flow path of the apparatus (to replicate an effect of
smoking a conventional combustible smoking article).
[0089] The aerosol generating apparatus may be portable. As used herein, the term "
portable" may refer to the apparatus being for use when held by a user.
[0090] As used herein, an "
aerosol generating system" may be a system that includes an aerosol generating apparatus and optionally other
circuitry/components associated with the function of the apparatus, e.g. one or more
external devices and/or one or more external components (here "external" is intended
to mean external to the aerosol generating apparatus).
[0091] As used herein, an "external device" and "external component" may include one or
more of a: a charging device, a mobile device (which may be connected to the aerosol
generating apparatus, e.g. via a wireless or wired connection); a networked-based
computer (e.g. a remote server); a cloud-based computer; any other server system.
[0092] An example aerosol generating system may be a system for managing an aerosol generating
apparatus. Such a system may include, for example, a mobile device, a network server,
as well as the aerosol generating apparatus.
[0093] As used herein, an "
aerosol" may include a suspension of precursor, including as one or more of: solid particles;
liquid droplets; gas. Said suspension may be in a gas including air. An aerosol herein
may generally refer to/include a vapour. An aerosol may include one or more components
of the precursor.
[0094] As used herein, a "
precursor" may include one or more of a: liquid; solid; gel; loose leaf material; other substance.
The precursor may be processed by an aerosol generating unit of an aerosol generating
apparatus to generate an aerosol. The precursor may include one or more of: an active
component; a carrier; a flavouring. The active component may include one or more of
nicotine; caffeine; a cannabidiol oil; a non-pharmaceutical formulation, e.g. a formulation
which is not for treatment of a disease or physiological malfunction of the human
body. The active component may be carried by the carrier, which may be a liquid, including
propylene glycol and/or glycerine. The term "flavouring" may refer to a component
that provides a taste and/or a smell to the user. The flavouring may include one or
more of: Ethylvanillin (vanilla); menthol, Isoamyl acetate (banana oil); or other.
The precursor may include a substrate, e.g. reconstituted tobacco to carry one or
more of the active component; a carrier; a flavouring.
[0095] As used herein, a "
storage portion" may be a portion of the apparatus adapted to store the precursor. It may be implemented
as fluid-holding reservoir or carrier for solid material depending on the implementation
of the precursor as defined above.
[0096] As used herein, a "
flow path" may refer to a path or enclosed passageway through an aerosol generating apparatus,
e.g. for delivery of an aerosol to a user. The flow path may be arranged to receive
aerosol from an aerosol generating unit. When referring to the flow path, upstream
and downstream may be defined in respect of a direction of flow in the flow path,
e.g. with an outlet being downstream of an inlet.
[0097] As used herein, a "
delivery system" may be a system operative to deliver an aerosol to a user. The delivery system may
include a mouthpiece and a flow path.
[0098] As used herein, a "
flow" may refer to a flow in a flow path. A flow may include aerosol generated from the
precursor. The flow may include air, which may be induced into the flow path via a
puff by a user.
[0099] As used herein, a "
puff" (or "
inhale" or "
draw") by a user may refer to expansion of lungs and/or oral cavity of a user to create
a pressure reduction that induces flow through the flow path.
[0100] As used herein, an "
aerosol generating unit" may refer to a device configured to generate an aerosol from a precursor. The aerosol
generating unit may include a unit to generate a vapour directly from the precursor
(e.g. a heating system or other system) or an aerosol directly from the precursor
(e.g. an atomiser including an ultrasonic system, a flow expansion system operative
to carry droplets of the precursor in the flow without using electrical energy or
other system). A plurality of aerosol generating units to generate a plurality of
aerosols (for example, from a plurality of different aerosol precursors) may be present
in an aerosol generating apparatus.
[0101] As used herein, a "
heating system" (or "heater") may refer to an arrangement of at least one heating element, which
is operable to aerosolise a precursor once heated. The at least one heating element
may be electrically resistive to produce heat from the flow of electrical current
therethrough. The at least one heating element may be arranged as a susceptor to produce
heat when penetrated by an alternating magnetic field. The heating system may be configured
to heat a precursor to below 300 or 350 degrees C, including without combustion.
[0102] As used herein, a "
consumable" may refer to a unit that includes a precursor. The consumable may include an aerosol
generating unit, e.g. it may be arranged as a cartomizer. The consumable may include
a mouthpiece. The consumable may include an information carrying medium. With liquid
or gel implementations of the precursor, e.g. an e-liquid, the consumable may be referred
to as a "capsule" or a "pod" or an "e-liquid consumable". The capsule/pod may include
a storage portion, e.g. a reservoir or tank, for storage of the precursor. With solid
material implementations of the precursor, e.g. tobacco or reconstituted tobacco formulation,
the consumable may be referred to as a "stick" or "package" or "heat-not-burn consumable".
In a heat-not-burn consumable, the mouthpiece may be implemented as a filter and the
consumable may be arranged to carry the precursor. The consumable may be implemented
as a dosage or pre-portioned amount of material, including a loose-leaf product.
[0103] As used herein, an "
information carrying medium" may include one or more arrangements for storage of information on any suitable
medium. Examples include: a computer readable medium; a Radio Frequency Identification
(RFID) transponder; codes encoding information, such as optical (e.g. a bar code or
QR code) or mechanically read codes (e.g. a configuration of the absence or presents
of cut-outs to encode a bit, through which pins or a reader may be inserted).
[0104] As used herein "
heat-not-burn" ("
HNB"), "
heated tobacco" ("HT"), or "
heated precursor" may refer to the heating of a precursor, typically tobacco, without combustion,
or without substantial combustion (i.e. localised combustion may be experienced of
limited portions of the precursor, including of less than 5% of the total volume).
[0105] As used herein, a "
processing resource" (or "
processor" or
"controller") may refer to one or more units for processing data, examples of which may include
an ASIC, microcontroller, FPGA, microprocessor, digital signal processor (DSP) capability,
state machine or other suitable component. A processing resource may be configured
to execute a computer program, e.g. which may take the form of machine readable instructions,
which may be stored on a non-transitory memory and/or programmable logic. The processing
resource may have various arrangements corresponding to those discussed for the circuitry,
e.g. on-board and/or off board the apparatus as part of the system. As used herein,
any machine executable instructions, or computer readable media, may be configured
to cause a disclosed method to be carried out, e.g. by an aerosol generating apparatus
or system as disclosed herein, and may therefore be used synonymously with the term
method.
[0106] As used herein, a "
computer readable medium/media" (or
"memory" or "
data storage") may include any medium capable of storing a computer program, and may take the
form of any conventional non-transitory memory, for example one or more of: random
access memory (RAM); a CD; a hard drive; a solid state drive; a memory card; a DVD.
The memory may have various arrangements corresponding to those discussed for the
circuitry /processor. The present disclosure includes a computer readable medium configured
to cause an apparatus or system disclosed herein to perform a method as disclosed
herein.
[0107] Referring to Fig. 1, an example aerosol generating apparatus 1 includes a power supply
2, for supply of electrical energy. The apparatus 1 includes an aerosol generating
unit 4 that is driven by the power supply 2. The power supply 2 may include an electric
power supply in the form of a battery and/or an electrical connection to an external
power source. The apparatus 1 includes a precursor 6, which in use is aerosolised
by the aerosol generating unit 4 to generate an aerosol. The apparatus 2 includes
a delivery system 8 for delivery of the aerosol to a user.
[0108] Electrical circuitry (not shown in figure 1) may be implemented to control the interoperability
of the power supply 4 and aerosol generating unit 6.
[0109] In variant examples, which are not illustrated, the power supply 2 may be omitted
since, e.g. an aerosol generating unit implemented as an atomiser with flow expansion
may not require a power supply.
[0110] Fig. 2 shows an implementation of the apparatus 1 of Fig. 1, where the aerosol generating
apparatus 1 is configured to generate aerosol by a heat not-burn / heated tobacco
process.
[0111] In this example, the apparatus 1 includes a device body 50 and a consumable 70.
[0112] In this example, the body 50 includes the power supply 4 and a heater 52. The heater
54 includes at least one heating element 54. The body may additionally include any
one or more of electrical circuitry 56, a memory 58, a wireless interface 60, one
or more other components 62.
[0113] The electrical circuitry 56 may include a controller for controlling one or more
operations of the body 50, e.g. based on instructions stored in the memory 58.
[0114] The wireless interface 60 may be configured to communicate wirelessly with an external
(e.g. mobile) device, e.g. via Bluetooth.
[0115] The other component(s) 62 may include an actuator, one or more user interface devices
configured to convey information to a user and/or a charging port, for example (see
e.g. Fig. 3).
[0116] The body 50 is configured to engage with the consumable 70 such that the at least
one heating element 54 of the heater 52 penetrates into the solid precursor 6 of the
consumable. In use, a user may activate the aerosol generating apparatus 1 to cause
the heater 52 of the body 50 to cause the at least one heating element 54 to heat
the solid precursor 6 of the consumable (without combusting it) by conductive heat
transfer, to generate an aerosol which is inhaled by the user.
[0117] Fig. 3 shows an example implementation of the aerosol generating device 1 of Fig.
2.
[0118] As depicted in Fig. 3, the consumable 70 is implemented as a stick, which is engaged
with the body 50 by inserting the stick into an aperture at a top end 53 of the body
50, which causes the at least one heating element 54 of the heater 52 to penetrate
into the solid precursor 6.
[0119] The consumable 70 includes the solid precursor 6 proximal to the body 50, and a filter
distal to the body 50. The filter serves as the mouthpiece of the consumable 70 and
thus the apparatus 1 as a whole. The solid precursor 6 may be a reconstituted tobacco
formulation.
[0120] In this example, the at least one heating element 54 is a rod-shaped element with
a circular transverse profile. Other heating element shapes are possible, e.g., the
at least one heating element 54 may be blade-shaped (with a rectangular transverse
profile) or tube-shaped (e.g. with a hollow transverse profile).
[0121] In this example, the body 50 includes a cap 51. In use the cap 51 is engaged at a
top end 53 of the body 50. Although not apparent from Fig. 3, the cap 51 is moveable
relative to the body 50. In particular, the cap 51 is slidable and can slide along
a longitudinal axis of the body 50.
[0122] The body 50 also includes an actuator 55 on an outer surface of the body 50. In this
example, the actuator 55 has the form of a button.
[0123] The body 50 also includes a user interface device configured to convey information
to a user. Here, the user interface device is implemented as a plurality of lights
57, which may e.g. be configured to illuminate when the apparatus 1 is activated and/or
to indicate a charging state of the power supply 4. Other user interface devices are
possible, e.g. to convey information haptically or audibly to a user.
[0124] The body may also include an airflow sensor which detects airflow in the aerosol
generating apparatus 1 (e.g. caused by a user inhaling through the consumable 70).
This may be used to count puffs, for example.
[0125] In this example, the consumable 70 includes a flow path which transmits aerosol generated
by the at least one heating element 54 to the mouthpiece of the consumable.
[0126] In this example, the aerosol generating unit 4 is provided by the above-described
heater 52 and the delivery system 8 is provided by the above-described flow path and
mouthpiece of the consumable 70.
[0127] Fig. 4 shows a method of controlling a power supply of an aerosol generating apparatus
according to aspects of the present invention, such as an HT device.
[0128] At step S100 the controller measures and stores usage data during at least one previous
consumable heating cycle of the aerosol generating apparatus. Preferably, usage data
is collected for a plurality of previous consumable heating cycles. The collected
data includes at least a minimum elapsed time period recorded between puffs (i.e.,
inhalations) from the apparatus during the previous consumable heating cycle.
[0129] At step S102 the controller determines a power profile for the heater based on the
collected usage data. The power profile comprises information relating to temperature
values for the heater and temperature durations for maintaining the heater at those
temperatures.
[0130] The temperature values for the heater include a first (operational) temperature for
when the user is inhaling from the apparatus and the heater is operating in a high
power setting, a second (standby) temperature for when the heater is operating in
a low power setting between inhalations, and, optionally, a third (preheating) temperature
which is higher than the second temperature and lower than the first temperature for
when the heater is primed for an inhalation to happen.
[0131] The temperature durations of the power profile include a low temperature duration
for maintaining the heater at the second temperature after an inhalation from the
apparatus. The low temperature duration may also be referred to as a deadtime since
the apparatus is not expected to be in use for generating an aerosol during this time.
[0132] Determining the power profile based on the collected data comprises calculating a
minimum low temperature duration based on the elapsed time periods between inhalations
that were recorded during the previous consumable heating cycles. This step is described
in more detail below in relation to Fig. 5.
[0133] At step S104, the controller applies the power profile to heater during a subsequent
consumable heating cycle. As described below in relation to Fig. 6, applying the power
profile comprises detecting inhalations (puffs) during the subsequent consumable heating
cycle, and in response to detecting the end of each inhalation, reducing the temperature
of the heater from the first temperature to the second temperature.
[0134] The heater is maintained at the second temperature for at least the low temperature
duration that was determined in step S102. In some examples, the controller is configured
to return the temperature of the heater to the first temperature after the low temperature
duration has elapsed. In other examples, as described below in relation to Fig. 6,
the controller is configured to increase the temperature of the heater to a third
(priming) temperature, which is lower than the first temperature, after the low temperature
duration has elapsed.
[0135] However, if a user inhales from the apparatus before the low temperature duration
has elapsed, then the controller is configured increase the temperature of the heater
to the first temperature immediately. In this case, the controller is also configured
to reset the previously determined low temperature duration to the current elapsed
duration since the previous inhalation.
[0136] Fig. 5 is a flowchart illustrating a method of measuring and storing usage data during
previous consumable heating cycles and updating the power profile for the heater based
on the measured usage data.
[0137] At step S200 the controller records how much time has elapsed between puffs (i.e.,
inhalations of an aerosol from the apparatus). The apparatus comprises a puff detector,
for example an airflow detector, which is configured to send a signal to the controller
indicating when the user is inhaling from the apparatus. By comparing when the user
is inhaling from the apparatus to a system clock, the controller can calculate how
long the user has waited after each puff before taking another puff from the apparatus.
[0138] At step S202 the controller determines whether the current consumable heating cycle
has ended. This may include determining if the consumable is empty, and/or if a new
consumable has been inserted in the apparatus, and/or if the apparatus has been turned
off since the last inhalation from the apparatus. If the consumable cycle has not
yet ended, then the controller continues to record the durations between puffs.
[0139] If the consumable heating cycle has ended, then the controller moves to step S203
where the shortest duration between recorded puffs is determined for the previous
consumable heating cycle. The shortest recorded duration is added to a database of
shortest recorded durations from a plurality of previous consumable heating cycles.
For example, the database may comprise the shortest recorded durations between puffs
for the previous six consumable heating cycles.
[0140] At step S204 the controller uses the database of recorded shortest durations to calculate
an average shortest duration for the plurality of previous consumable heating cycles.
The average indicates the average minimum time that the user of the apparatus tends
to wait between puffs. In some examples, the average may be calculated for all of
the previous consumable heating cycles of the apparatus. In other examples, the average
may be a continuous average which is calculated and updated for a predetermined plurality
of the previous consumable heating cycles.
[0141] At step S206 the controller updates the power profile for the heater by setting the
low temperature duration for maintaining the heater at the second temperature to the
average shortest duration that was calculated in step S204.
[0142] At step S208 a new consumable heating cycle is started by the user, for example by
turning on the apparatus or by inserting a new consumable in the apparatus. The updated
power profile is applied to the heater during the new consumable cycle and the controller
returns to step S200 to begin recording durations between puffs during the new consumable
heating cycle.
[0143] Fig. 6 is a flowchart illustrating a method of controlling a heater of an aerosol
generating apparatus according to aspects of the present invention. Specifically,
Fig. 6 shows a method of applying the calculated power profile to the heater of the
aerosol generating apparatus during a consumable heating cycle.
[0144] At step S300, the controller detects the end of an inhalation (i.e., a puff) from
the apparatus by a user. The occurrence of the end of the puff may be determined by
the end of a signal from a puff sensor indicative of the presence of a puff. During
the puff, the temperature of the heater is a first temperature which is suitable for
producing an aerosol from the aerosol precursor.
[0145] In response to the detecting of the end of the inhalation, the controller moves to
step S302 where the temperature of the heater is reduced from the first temperature
(the temperature of the heating element during the puff) to a second temperature.
[0146] In step S304, the temperature of the heater is maintained for at least the low temperature
duration or until the user takes another puff of the apparatus. The low temperature
duration and the first and second temperatures are defined in the power profile which
was determined as described above in relation to Fig. 5.
[0147] However, if the present consumable heating cycle is a first consumable heating cycle
of the apparatus, then the controller is configured to apply an initial power profile
to the heater. The initial power profile comprises a predetermined low temperature
duration for maintaining the temperature of the heater at the second temperature after
a puff. For example, the initial low temperature duration may be between 0.5 seconds
and 10 seconds.
[0148] At step S306 the temperature of the heater is optionally increased to a third temperature
after the low temperature duration has elapsed. The third temperature may be referred
to as primer temperature which is higher than the second temperature and lower than
the first temperature.
[0149] The temperature of the heater is maintained at the third temperature until the start
of a subsequent puff is detected in step S308. In response to detection the puff,
the temperature of the heater is increased to the first temperature at step S310.
Therefore, the heater is returned to the first temperature, which is suitable for
producing an aerosol, for the duration of the puff.
[0150] Fig. 7 is a temperature/time chart depicting a portion of a heating characteristics
of the heater during a consumable cycle. In this example, the chart shows the temperature
of the heater during two inhalations from the apparatus by a user. Although, for illustrative
purposes, changes in temperature are depicted as being instantaneous, it may be appreciated
that such changes would occur over a period of time (depending on the rate at which
the heater is able to increase/decrease in temperature).
[0151] At time t0 the temperature of the heater is the ambient (environmental) temperature
TA (e.g. 25°C). At t1, the user activates the aerosol generating apparatus, which
causes the controller to increase the temperature of the heater to a priming temperature
(i.e., the third temperature) T3, which may be approximately 250°C. This temperature
T3 may be above a minimum aerosol generating temperature at which an aerosol is able
to be generated from an aerosol former by the heater. Alternatively, the priming temperature
may be chosen such that the heater is able to be heated from the priming temperature
to a first temperature T1 (i.e. the temperature during a puff) within a particular
time period.
[0152] At time t2 the user initiates a puff 401a (inhale) on the apparatus, which is detected
by a puff sensor. In response to the detection of the start of the puff 401a, the
controller controls a power supply to the heater to increase the temperature of the
heater from the priming temperature T3 to a first temperature T1. The first temperature
T1 is a temperature at which an aerosol having desired properties may be generated
from the aerosol former. The first temperature T1 is maintained for the duration of
the puff 401a (from time t2 to time t3).
[0153] At time t3 the end of the puff 401a is detected and, in response, the method of Fig.
6 is implemented by the controller. That is, the controller controls the heater to
reduce the temperature of the heater to a second temperature T2. The second temperature
T2 is then maintained for a period (from time t3 to t4), which is the low temperature
duration 400 calculated as described above for determining the power profile for the
heater.
[0154] By maintaining the temperature of the heater at the reduced second temperature T2
for the low power duration 400, the power consumption of the heater may be reduced.
As the low power duration 400 is immediately after the end of the puff 401a, it is
unlikely a user will begin another puff during this time period (and, as such, any
detriment to the experience of the user is minimised).
[0155] At time t4, after the low temperature duration 400, the temperature of the heater
is increased again to the priming (third) temperature T3. This ensures that, when
a user takes a subsequent puff 401b, the heater is at a temperature at which it is
either capable of generating an aerosol from the aerosol former, or can be heated
to such a temperature within a desired time period (i.e. a time period small enough
so as not to be noticeable by a user).
[0156] At time t5, the user takes a second puff 401b, which is longer than the first puff
401a. The end of this puff is detected at t6 and the method of Fig. 6 is again implemented.
That is, the temperature of the heater is reduced by the controller to the second
temperature T2 and maintained for the low power duration 400 (from time t6 to t7).
Notably, as the low temperature duration is determined for the current consumable
cycle it is the same for both the first 401a and second 401b puffs.
[0157] Following the low temperature duration 400, the temperature of the heater is again
increase to the third temperature T3. As should be appreciated, the method of Fig.
6 may be repeated for each subsequent puff until the present consumable cycle is ended
and the heater is deactivated.
[0158] As well as adjusting the temperature of the heater according to the power profile,
the controller is also configured to simultaneously record usage data of the apparatus
(i.e., the elapsed time between puffs) during the present consumable cycle in order
to update the power profile for future consumable cycles as described above in relation
to Fig. 5. Accordingly, the low power duration and hence the power savings of the
apparatus may be tailored and updated to anticipate the habits of a specific user
of the apparatus.