Aerosol-forming system with a removable and a temporary energy storage

Abstract

An aerosol-forming system including an energy storage compartment configured to receive a removable energy storage, a temporary energy storage, the temporary energy storage not being a battery, a charging circuit, configured to electrically connect the temporary energy storage to the removable energy storage and configured to at least partially charge the temporary energy storage from the removable energy storage, the charging circuit using a synchronous rectifier, a heating device, and a discharging circuit, electrically connecting the heating device to the temporary energy storage, wherein the discharging circuit is configured to power the heating device.

Description

[0001] AEROSOL-FORMING SYSTEM WITH A REMOVABLE AND A TEMPORARY ENERGY STORAGE

[0002] The present disclosure relates to an aerosol-forming system and aerosol-forming device. The present disclosure further relates to a method for powering a heating device in an aerosolforming system or aerosol-forming device.

[0003] Aerosol-forming or aerosol-generating devices are typically designed as handheld devices that can be used by a user for consuming or experiencing, for instance in one or more usage sessions or one or more puffs, aerosol generated from an aerosol-forming substrate or an aerosol-forming article, for example by heating. The aerosol-forming devices according to aspects of the present invention are mainly directed to the field of tobacco and tobacco-substitute products, as well as e-vapor devices, for example heated tobacco products (HTP), heat-not-burn (HnB) devices, electronic cigarettes, e-vapor devices, and / or vaporisers. The aerosol-forming devices according to aspects of the present invention may also pertain to other types of inhalers, dispensers, or atomizers, for example inhalers, dispensers, or atomizers for example for medical applications.

[0004] Typical aerosol-forming systems can be designed as one-part systems or devices including an aerosol-forming device that can be operated by a user to generate aerosol. Alternatively, aerosol-forming systems can be designed as two-part systems or devices comprising an aerosolforming device and a companion device for accommodating and / or charging the aerosol-forming device. In either design or configuration, the aerosol-forming system or device can be used by a user for consuming or inhaling, for instance in one or more usage sessions, aerosol generated based on heating an aerosol-forming article or substrate couplable to the aerosol-forming system. In the context of the present disclosure, an aerosol-forming device can refer to both a one-part device and a two-part device, unless explicitly specified otherwise.

[0005] The aerosol-forming article, also referred to as aerosol-generating article, can comprise an aerosol-generating or aerosol-forming substrate having one or more active ingredients, such as a tobacco or nicotine-containing substrate, for example in liquid or solid form. The aerosol-forming article may be configured in shape and size to be inserted at least partially into the aerosol-forming device or system. In conventional systems or devices, the aerosol-forming article is usually formed as a stick that can be at least partly inserted into a cavity or heating chamber of the aerosol-forming device for aerosol consumption. In other conventional systems or devices, the aerosol-forming article can include a cartridge or container having a reservoir that contains a liquid aerosol-forming substrate that can be fixed or removably received by a holder having a battery.

[0006] Exemplary aerosol-forming substrates can comprise solid substrate material, such as tobacco material or tobacco cast leaves (TCL) material. The substrate material can, for example, be assembled, often with other elements or components, to form a substantially stick-shaped or cuboid-shaped aerosol-forming article. Such aerosol-forming article can be configured in shape and size to be inserted at least partially into the aerosol-forming device. The aerosol-forming device may comprise a heating element or heater device for heating the aerosol-forming article and / or the aerosol-forming substrate. The heating element or heater device may be part of the aerosol-forming article and / or the aerosol-forming device. Alternatively or additionally, aerosolforming substrates can comprise one or more liquids and / or solids, which can, for example, be supplied to the aerosol-forming device in the form of a cartridge or container. Corresponding exemplary aerosol-forming articles can, for example, comprise a cartridge containing or fillable with the liquid and / or solid substrate, which can be vaporized during aerosol consumption by the user based on heating the substrate and / or liquid. Usually, such cartridge or container can be coupled to, attached to or at least partially inserted into the aerosol-forming device. Alternatively, the cartridge may be fixedly mounted to the aerosol-forming device and refilled by inserting liquid and / or solid into the cartridge. The aerosol generated from the aerosol-forming substrate or article may comprise or include one or more active ingredients, such as nicotine, aroma, sugar, moisturising agent, botanicals, preservative, flavouring, for example cocoa, liquorice, menthol and lactic acid or other additives. The aerosol generated from the aerosol-forming substrate or article may additionally or alternatively comprise one or more pharmaceutical agents or drugs and may include one or more adjuvants.

[0007] For generating the aerosol during use or consumption, heat can be supplied by a heating element, heater device or heat source to heat at least a portion or part of the aerosol-forming substrate. The heating element, heater device or heat source can be arranged in the handheld device or a handheld part of the aerosol-forming device. Alternatively or additionally, at least a part of or the entire heating element or heater device or heat source can be fixedly associated with or arranged within an aerosol-forming article, for instance in the form of a stick, cuboid, or cartridge, which can be attached to and / or powered by the handheld device or handheld part of the aerosol-forming device.

[0008] Exemplary heating elements or heater devices can be based on one or more of resistive heating, inductive heating, dielectric or microwave heating, radiative heating, or other heating type using electrical energy supplied via, drawn from or stored in an energy storage or battery of the aerosol-forming device. As used herein, a battery of the aerosol-forming device can generally refer to an energy storage of the aerosol-forming device configured to store electrical energy. Accordingly, the term energy storage can include one or more batteries, one or more capacitors, one or more accumulators or other types of energy storage. Also, any reference to a battery herein can include a plurality of batteries, as well as any reference to a capacitor herein can include a plurality of capacitors, except where stated otherwise. Typically, aerosol-forming devices comprise an energy storage, for example a battery, providing the electrical energy needed to operate the aerosol-forming device and especially for heating the aerosol-forming substrate and / or article, for example to generate aerosol in one or more usage sessions using one or more aerosol-forming articles. The battery may, for example, be a lithium-ion battery.

[0009] As used herein, a usage session may refer to a period of time, during which a user may use the device to generate, consume, experience or inhale aerosol using the aerosol-forming device. Therein, a usage session may be finite. In other words, a usage session may have a start, an end and a duration. The duration of the usage session as measured by time may be influenced by use during the usage session. The duration of the usage session may have a maximum duration determined by a maximum time from the start of the usage session. The duration of the usage session may be less than the maximum time if one or more monitored parameters reaches a predetermined threshold before the maximum time from the start of the usage session.

[0010] One of the advantages of aerosol-forming systems in comparison to conventional tobacco and tobacco-substitute products may be the reusability of aerosol-forming systems or devices. An aerosol-forming system may last multiple years before it needs to be replaced. Typically, the first component of an aerosol-forming system which needs to be swapped may be the energy storage or battery due to decreasing capacity. However, the compact handheld design of aerosolforming systems may make it difficult to replace an energy storage, for example a battery which no longer supplies sufficient voltage, as they tend to be fixedly built-in to the system or device, requiring special tooling and skill for battery removal. Without a convenient possibility for a user to repair the aerosol-forming system, the user may dispose of the system, which is fully functional except for the battery, unnecessarily reducing the lifetime of the aerosol-forming system and creating dangerous waste. This may reduce user experience and have a negative environmental impact.

[0011] Another problem in this regard may be that standard batteries that are available to the consumer or user in retail typically cannot supply sufficient power and / or voltage and / or current needed for heating the heating device of an aerosol-forming device. In use, the heating device needs to be heated to high temperatures, for example several hundred degrees Celsius, in a very short time, for example in less than a second. Especially during a puff of a user in puff-on-demand applications for e-vapor type devices, a power spike is necessary to heat the heating device to aerosolization temperature that is factors larger than what a standard battery can deliver. Similarly, for heat-not-burn devices, the heat-up phase requires a heating power that is factors larger than what a standard battery can deliver. Retail-available standard batteries are not able to provide the necessary power, especially not in such short amounts of time. Therefore, typically, aerosol-forming devices are provided with special batteries, which may not be available in retail and which are generally unsuitable to be easily and readily replaced by the user.

[0012] It may therefore be desirable to provide for an improved aerosol-forming system having the possibility of using standard batteries available in retail in an aerosol-forming device without cutbacks in user experience, thereby fully avoiding the use of device-specific batteries. Additionally, it would be desirable to provide the user with a convenient way to replace the battery. For example, it may be desirable to provide a possibility to remove and replace the energy storage of an aerosol-forming system without any tools.

[0013] These advantages may be achieved by the features described herein.

[0014] According to an aspect of the present invention, there is provided an aerosol-forming system including an energy storage compartment configured to receive a removable energy storage, a temporary energy storage, the temporary energy storage not being a battery, a charging circuit configured to electrically connect the temporary energy storage to the removable energy storage and configured to at least partially charge the temporary energy storage from the removable energy storage, the charging circuit comprising and / or using a synchronous rectifier, a heating device, and a discharging circuit, electrically connecting the heating device to the temporary energy storage, wherein the discharging circuit is configured to power the heating device.

[0015] The energy storage compartment may comprise a receptacle space for the removable energy storage. For example, the receptacle space may be provided in a chamber provided by a housing. At least one of the walls of the energy storage compartment and / or the housing may include a movable lid or door, which may be configured to be openable for providing access to the receptacle space for inserting or removing the removable energy storage. The lid or door may also be closable for securely storing the removable energy storage during use of the aerosolforming system. The energy storage compartment may also comprise electrical contacts or leads for electrically connecting the removable energy storage to the charging circuit and / or other components and / or electrical loads of the aerosol-forming system. The energy storage compartment may be configured to receive and / or store a specific type of removable energy storage as explained herein. This may mean that the energy storage compartment and / or the receptacle space may have dimensions and / or a shape and / or electrical contacts or leads corresponding to and / or matching the removable energy storage.

[0016] The removable energy storage may be manually inserted and / or removed from the energy storage compartment by a user. For this, the energy storage compartment may be configured to be manually openable and / or closable by the user. The energy storage compartment may be configured for tool-free insertion and / or removal of the removable energy storage. For example, it may not be necessary to use any tools and / or any specialised knowledge to insert or install the removable energy storage into the energy storage compartment and to electrically connect the energy storage compartment to the removable energy storage or to remove it again. The usability of the aerosol-forming system as well as the user’s experience may therefore be improved by more easily and faster providing energy to the aerosol-forming system. Also, depleted energy storages may be replaced by charged ones, avoiding having to wait for the energy storage to recharge. When a removable energy storage is inserted into the energy storage compartment, the energy storage compartment may provide energy from the removable energy storage to the temporary energy storage.

[0017] The temporary energy storage may be any component configured and / or able to temporarily store energy, for example electrical energy, supplied from the removable energy storage, for example through the charging circuit. In particular, the temporary energy storage may be configured to be charged by the charging circuit and to store the energy received until it is needed to supply and / or power the aerosol-forming system, particularly the heating device. Thus, the temporary energy storage may be configured as an intermediate energy storage between the removable energy storage and an electrical load, particularly the heating device. The temporary energy storage may be configured to receive, to temporarily store and to provide electrical power. Particularly, the temporary energy storage may be configured to provide an electrical power and / or voltage and / or current different, for example higher or lower, from a power and / or voltage and / or current provided for charging the temporary energy storage by the removable energy storage and / or the charging circuit. For example, the power and / or voltage and / or current provided by the temporary energy storage, for example to the discharging circuit and / or the heating device, may be independent of the power and / or voltage and / or current providable by the removable energy storage. For example, the power and / or voltage and / or current provided by the temporary energy storage may be higher than the power and / or voltage and / or current providable by the removable energy storage. This may be achieved by loading the temporary energy storage beforehand, for example for a longer time than the time during discharging the temporary energy storage. However, it is noted that the temporary energy storage does not comprise a battery. In other words, the temporary energy storage is not a battery. Instead, as will be explained in more detail herein, the temporary energy storage may, for example, be a supercapacitor. A standard retail-available battery (e.g. an AA-type battery) cannot deliver enough current for powering the heater. However, such batteries may be used to pre-charge the temporary energy storage, which may then in turn power the heater.

[0018] As an example, the power that can be constantly delivered by a standard retail-available replaceable battery typically lies somewhere in the range between 0.5 W to 1.5 W. This is usually insufficient to provide for the instantaneous power for a puff in an aerosol-forming device, or for providing for sufficient energy to heat-up a substrate to a maintenance temperature. For example, an e-vapor device may need power during a puff in a range between 5 W to 50 W and the power necessary for a usage session, heating session, or warm-up phase of a heat-not-burn type device as another example of an aerosol-forming device may be between 2 W and 20 W, depending on the time of the temperature profile. Therefore, according to at least some aspects of the present disclosure, the power of the removable energy storage, for example the battery, may not be delivered to the heating device and / or the heater power circuit but may be used to charge the temporary energy storage. Once the temporary energy storage is charged or has sufficient energy available for heating, the energy of the temporary energy storage may be delivered to the heating device and / or the heater power circuit. Given the longer lifecycle of the types of temporary energy storage explained in more detail herein, relative to a battery, a device may be provided that can have a longer life cycle, and may be recycled without the need of extracting a battery module.

[0019] The charging circuit may comprise a synchronous rectifier, which may also be called an active rectifier. Typically, synchronous rectifiers comprise an actively controlled switch, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or a bipolar junction transistor (BJT). Thus, synchronous rectifiers may be used to replace diodes. In fact, synchronous rectifiers may be free of diodes or diode-free. In the present context, for example the charging circuit may be free of diodes or diode-free. Using synchronous rectifiers instead of diodes leads to a significantly lower voltage drop over the charging circuit, preventing or minimizing power loss. This may be especially important in the present implementation, which aims to function using retail-available batteries, which may typically provide only a low voltage (for example 1.5 V). With normal semiconductor diodes having a roughly fixed voltage drop of around 0.5 V to 1 V, this may lead to significant power loss in the context of the present disclosure. The use of a synchronous or active rectifier may alleviate this problem and increase power efficiency to the point that using retail-available batteries, for example AA-type batteries, becomes feasible when combined with a temporary energy storage as explained herein.

[0020] The heating device may be configured to form an aerosol from an aerosol-forming article or substrate by heating said aerosol-forming article or substrate. To this end, the heating device may include one or multiple heating elements, for example for resistive heating and / or inductive heating, dielectric or microwave heating, and / or radiative heating using energy supplied via the discharging circuit from the temporary energy storage. Typically, the heating device may have high power requirements when heating the aerosol-forming article or substrate from an ambient temperature to a temperature maintained during a usage session and / or puff and when heating the aerosol-forming article or substrate during the usage session for forming or generating aerosol. These requirements for heating the aerosol-forming article or substrate to a maintenance temperature and / or to an aerosol ization temperature may not be fulfillable by the power output and / or current output and / or voltage output of the removable energy storage. However, these requirements may be met or fulfillable by the power output and / or current output and / or voltage output of the temporary energy storage, which may be higher than the output of the removable energy storage. In other words, the removable energy storage may be of low power output, for example lower than the requirements, for example minimum requirements, of the heating device during a usage session and / or a puff. On the other hand, in some embodiments, the temporary energy storage may be configured to provide a power output and / or current output and / or voltage output sufficient for the heating device during the usage session and / or a puff. In this way, the invention may enable the use of removable energy storages which would normally not be suitable for the aerosol-forming system by providing the temporary energy storage as an intermediate energy storage between the removable energy storage and the heating device. The invention may therefore, by provision of the temporary energy storage, allow the use of conventional retailtype batteries in the aerosol-forming device, as described in more detail below.

[0021] The aerosol-forming device and / or the aerosol-forming system according to at least some aspects of the present invention may be battery-free and may merely be configured to receive a removable energy storage. When the removable energy storage has been removed from the aerosol-forming device and / or the aerosol-forming system, the aerosol-forming device and / or the aerosol-forming system may then be battery-free. In other words, the removable energy storage may be the only energy storage used in the aerosol-forming device and / or the aerosol-forming system. By being battery-free, the aerosol-forming device and / or the aerosol-forming system itself according to aspects of the present invention is also free of battery chemicals and may therefore be less hazardous to recycle and / or to dispose of. When the lifecycle of an aerosol-forming device and / or the aerosol-forming system ends, this may mean that the battery does not have to be disposed of and / or recycled automatically along with the aerosol-forming device and / or the aerosol-forming system, which may improve the environmental impact of the present system or device. In addition, battery explosion or degassing can be avoided.

[0022] The temporary energy storage may be permanently and / or solidly and / or irremovably installed in the aerosol-forming system. In other words, the temporary energy storage may not be removable from the aerosol-forming system without destroying the aerosol-forming system or components thereof. Furthermore, this may mean that the temporary energy storage may be reusable and may have a long life cycle as well as a high endurance with a low internal wear, for example in comparison to the removable energy storage.

[0023] The charging circuit may be configured to provide the temporary energy storage with a power and / or voltage and / or current from the removable energy storage necessary and / or suitable for charging the temporary energy storage. In other words, the charging circuit may electrically link the removable energy storage to the temporary energy storage. The discharging circuit may be configured to provide the heating device with a power and / or voltage and / or current from the temporary energy storage necessary and / or suitable for heating the aerosol-forming article or substrate. In other words, the discharging circuit may electrically link the heating device to the temporary energy storage. For example, the discharging circuit may be configured to at least partially discharge the temporary energy storage to power the heating device. To this end, the discharging circuit may provide electric energy to the heating device. In other words, the heating device may use electrical energy, for example power and / or voltage and / or current from the temporary energy storage, to heat the aerosol forming substrate or article for aerosolization.

[0024] The temporary energy storage may be configured to store at least 200 joules or at least 400 joules or at least 600 joules or at least 800 joules or at least 1000 joules. The minimum total energy capacity of the temporary energy storage may be, for example, at least 0.05 Wh or at least 0.1 Wh or at least 0.15 Wh or at least 0.2 Wh or at least 0.25 Wh or at least 0.3 Wh. In other words, the temporary energy storage may be able, for example, to hold at a nominal voltage of between 1 .5 volts and 1 .7 volts or between 1.2 volts and 1.7 volts at least 0.01 Ah or at least 0.05 Ah or at least 0.1 Ah or at least 0.15 Ah or at least 0.2 Ah. In particular, the minimum storable energy level or minimum total capacity of the temporary energy storage may correspond to or be sufficient for at least one usage session, particularly a complete usage session or a part of at least one usage session.

[0025] The energy may be stored in the temporary energy storage in any suitable form, for example in mechanical and / or electrical and / or electromagnetic and / or thermal and / or electrochemical and / or chemical form. For example, in a variant, the temporary energy storage may include a flywheel energy storage (FES). In particular, the temporary energy storage may include a capacitor, preferably a supercapacitor. In principle, capacitors such as supercapacitor, also known as ultracapacitors, store electric energy in an electric field. In other words, supercapacitors primarily store electric energy in a physical way in comparison to batteries, which primarily use chemical processes to produce a charge difference. Capacitors, especially supercapacitors excel in their power density and distinguish themselves from for example batteries with high power density and short charging and discharging times and the high amount of charging and discharging cycles without or with minimal degradation. In other words, a supercapacitor may provide a large amount of energy in a short amount of time by being discharged. At the same time supercapacitors may be charged in an equally short amount of time. In particular, capacitors, such as supercapacitors, may be charged and / or discharged faster than for example batteries. The supercapacitor may be configured to provide a maximum voltage between 1.6 volts and 6 volts, preferably 1.7 volts and 5 volts, more preferably between 1.7 volts and 4 volts. This may mean that the supercapacitor may provide a power output and / or current output and / or voltage output sufficient for powering the heating device during a usage session and / or a puff of the aerosol-forming device. Furthermore, exclusively one supercapacitor may suffice to provide a maximum voltage between 1.6 volts and 6 volts or between 1.7 volts and 5 volts or between 1 .7 volts and 4 volts. It may therefore be provided that the aerosol-forming system comprises exclusively one supercapacitor, which may keep the complexity of the system and production costs low. Also, temporary energy storages or supercapacitors able to provide higher voltages are bigger and more expensive, making them unsuitable for handheld aerosol-forming systems.

[0026] The energy storage compartment may be configured to receive a removable energy storage providing a nominal voltage of or of about 1.7 volts or about 1.5 volts or about 1.2 volts. These values are typical for commercially available retail batteries, which may be easily acquired by the user for installation or replacement in the aerosol-forming system. In other words, the energy storage compartment may be configured to receive standard sized battery, for example a AA-type battery or a AAA-type battery or a C-type battery or a D-type battery, preferably an AA-type battery or a C-type battery, most preferably an AA-type battery. While these batteries may be too weak to provide the electric power necessary for operation of the aerosol-forming system, the temporary energy storage according to aspects of the present invention circumvents this problem. Batteries providing a nominal voltage of the mentioned magnitude are typically standardized, which may mean that their shape, size and weight are known beforehand and well-defined. That the energy storage compartment is configured to receive a removable energy storage of the mentioned nominal voltages may therefore mean that the energy storage compartment is provided in a size, shape and design suitable for receiving and storing at least one or exclusively one of these batteries. The shape, size and design of the energy storage compartment may therefore correspond to the standardized shape, size and design of the removable energy storage to be received in the energy storage compartment.

[0027] Generally, the types of battery mentioned herein may conform to the standards and nomenclature as defined by the International Electrotechnical Commission (IEC), for example according to the norm I EC-60086. Therefore, a AA-type battery may be a R6-type battery according to I EC-60086, a AAA-type battery may be a R03-type battery according to I EC-60086, a C-type battery may be a R14-type battery according to IEC-60086, and a D-type battery may be a R20-type battery according to IEC-60086. According to these types, the sizes and shapes of the batteries are standardized and may be looked up in the respective documentation. Rechargeable batteries of similar size as the non-rechargeable batteries mentioned in the norm IEC-60086 may also be used. Within the present disclosure, all mentioned battery types may be rechargeable or non-rechargeable unless otherwise specified.

[0028] For example, the energy storage compartment may be configured to removably receive a battery, for example a rechargeable or non-rechargeable battery, for example exclusively one standard sized AA-type battery or exclusively one standard sized AAA-type battery or exclusively one standard sized C-type battery or exclusively one standard sized D-type battery, preferably exactly one AA-type battery or exactly one C-type battery, most preferably exactly one AA-type battery. These may be advantageous due to the small size and weight demands for portable and handheld aerosol-forming devices and systems, and also to reduce complexity of the compartment. This may mean that a user may buy a standard battery in any retail store, irrespective of the fact that these batteries are normally insufficient for operating the aerosolforming system. According to at least some aspects of the present invention, the battery is only used to charge the temporary energy storage over a comparatively longer amount of time as compared with a time for a usage session and / or a puff of the user. The temporary energy storage may then provide the higher amount of electric power necessary for operating the aerosol-forming system during a pre-heating phase and during a puff of the user.

[0029] The charging circuit may be implemented as any electrical component or circuit suitable for providing the temporary energy storage with the appropriate charging power and / or voltage and / or current for charging the temporary energy storage from the removable energy storage. For example, the charging circuit may be or may comprise a converter or converter circuit configured to adapt the output of the removable energy storage to the input requirements of the temporary energy storage. In a specific application, the charging circuit may include or may be a first DC- DC converter. The first DC-DC converter may for example be a buck-boost converter. A buckboost converter may be a type of DC-to-DC converter that has an output voltage amplitude that is either greater than or less than the input voltage amplitude. It may be able to produce a range of output voltages ranging from much larger, in absolute magnitude, than the input voltage, down to almost zero or zero. The DC-DC conversion of the charging circuit may be controlled by a controller and / or processor of the aerosol-forming system or device according to the output of the removable energy storage and the necessary input of the temporary energy storage.

[0030] For example, the charging circuit may be configured to step-down an output voltage, particularly an output voltage of the removable energy storage, to the temporary energy storage below the nominal voltage of the removable energy storage until zero volts or close to zero volts. This may be required as the removable energy storage provides for a substantially fixed voltage level, while the temporary energy storage, in the case of a supercapacitor, may be fully or close to fully discharged and needs to be charged with electrical energy. Alternatively, the charging circuit may be configured to step-up the output voltage, particularly the output voltage of the removable energy storage, to the temporary energy storage to a maximum charging voltage and / or an operating voltage of the temporary energy storage. In some configurations, the maximal charging voltage of the temporary energy storage will be higher than the voltage provided by the removable energy storage. In other words, the charging circuit may be configured to provide a power and / or voltage and / or current output corresponding to the power and / or voltage and / or current necessary for charging the temporary energy storage from a depleted or approximately depleted state to a fully charged state of the temporary energy storage. In this way, the temporary energy storage may be fully charged by the electrical energy provided from the removable energy storage despite the removable energy storage at least partly not being able to provide the necessary charging power and / or voltage and / or current.

[0031] For efficiently and reliably heating the aerosol-forming article or substrate up to aerosolization temperature, the heating device may need a constant power or constant voltage or constant current supply to operate. Therefore, the discharging circuit may be configured to provide a constant power output or a constant voltage or a constant current to the heating device. During the heating operation, it may be desirable not to fully discharge the temporary energy storage. Instead, upon reaching a pre-defined voltage level of about 5% to 30% of the nominal voltage that remains across the temporary energy storage, the heating operation may be stopped or disabled, for example by the controller and / or processor of the aerosol-forming system. For, example, upon discharging to a predetermined voltage level, e.g. in a range between 0.4 V and 0.8 V, the heating session or usage session may be stopped, and the recharging of the temporary energy storage may be triggered or enabled. This may be done to avoid that too much current needs to be pulled from the temporary energy storage above a safe operating level, when the voltage drops due to discharge, while the heating power remains substantially constant during the heating phase. To achieve this, the discharging circuit may be configured to discharge the temporary energy storage to a minimal non-zero operation voltage at which power delivery is still possible. The minimal non-zero operation voltage may be at least 5% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% of the nominal operating voltage of the temporary energy storage. The nominal operating voltage of the temporary energy storage may be the voltage providable by the temporary energy storage when it is fully charged.

[0032] The discharging circuit may be implemented as any electrical component or circuit suitable for providing the heating device with the appropriate heating power and / or voltage and / or current for heating the aerosol-forming article or substrate from the temporary energy storage. For example, the discharging circuit may be or may comprise a converter or converter circuit configured to adapt the output of the temporary energy storage to the input requirements of the heating device. In a specific application, the discharging circuit may include or may be a second DC-DC converter. The second DC-DC converter may for example be a buck-boost converter. The DC-DC conversion of the discharging circuit may be controlled by a controller and / or processor of the aerosol-forming system according to the output of the temporary energy storage and the necessary input of the heating device.

[0033] The discharging circuit may be configured to step-down an output voltage of the temporary energy storage to the heating device below a maximum voltage and / or the operating voltage of the temporary energy storage, for example to the minimal non-zero operation voltage. Alternatively, the discharging circuit may be configured to step-up the output voltage of the temporary energy storage to the heating device, for example while the voltage of the temporary energy storage drops during the provision of electric energy from the temporary energy storage to the heating device. In other words, the discharging circuit may be configured to provide a power and / or voltage and / or current output corresponding to the power and / or voltage and / or current necessary for heating the aerosol-forming article or substrate during the usage session or puff by the user independently of the charge state of the temporary energy storage, as long as the charge state is above the minimal non-zero operation voltage. In this way, the temporary energy storage may be fully discharged by providing the electrical energy from the temporary energy storage to the heating device, wherein fully discharged may mean a discharge down to the minimal nonzero operation voltage. Because the voltage of the temporary energy storage may continually drop during discharge, the discharging circuit may be configured to adapt and / or react to this voltage drop by adapting the energy conversion by the discharging circuit. This may be achieved through control by the controller and / or the processor of the aerosol-forming system.

[0034] In general, the charging circuit and / or the discharging circuit may comprise any suitable components for achieving the functionalities explained herein. For example, conventional converters, for example DC-DC converters, typically employ diodes as rectification elements. However, diodes typically result in significant voltage drops in their on-state, which may reduce efficiency of the respective circuit, especially given the relatively low voltage of the standard energy storage elements, e.g. batteries, that is typically around 1.5 V, and also given the relatively low operating voltages of the temporary energy storage. Therefore, the charging circuit and / or the discharging circuit may include an active rectification element, for example including a field-effect transistor (FET), for example a metal-oxide-semiconductor field-effect transistor (MOSFET) replacing the function of the classic diode. In a specific embodiment, the charging circuit and / or the discharging circuit may comprise two such FETs or MOSFETs each. This may provide the desired buck-boost functionality while avoiding the use of diodes for maintaining low voltage drops during the one-state of the DC-DC converter for increased efficiency.

[0035] As mentioned, the discharging circuit may be configured to convert the output power and / or voltage and / or current of the temporary energy storage into a suitable input power and / or voltage and / or current for the heating device. In a specific embodiment, the output power and / or voltage and / or current of the temporary energy storage may be higher than the input necessary for the heating device. This may be especially true in cases in which the temporary energy storage is implemented as a supercapacitor, where during the energy consumption, the voltage level of the supercapacitor continuously drops. An implementation of low cost and low complexity may then be achieved by the discharging circuit being or including a pulse-width modulation (PWM) controlled switch. The length and frequency of the pulses may be controlled by the controller and / or the processor of the aerosol-forming system. In this way, a constant power and / or voltage and / or current input at the heating device may be achieved despite the output voltage of the temporary energy storage changing, e.g. dropping, during discharge.

[0036] More specifically, at times, the temporary energy storage may require a higher voltage for charging than suppliable by the removable energy storage. In turn, the heating device may require a higher voltage for heating than suppliable by the temporary energy storage. For this reason, it may be provided that the charging circuit and / or the discharging circuit is configured to increase, for example to multiply, an input voltage. For example, the charging circuit and / or the discharging circuit may be configured as a voltage doubler or as a voltage tripler. The increased or multiplied voltage may then be supplied as an output to the temporary energy storage and / or the heating device, respectively.

[0037] As a specific example, the charging circuit and / or the discharging circuit may include a charge pump, for example a Dickson charge pump. Dickson charge pumps may be specifically suitable for the present application, because they are specialized components for low voltage applications, as described herein. Their application may therefore increase efficiency of the present system.

[0038] The high power output of the temporary energy storage may be especially useful for boost phases of the heating device, in which the temperature of the aerosol-forming article or substrate has to be increased very quickly. For example, boost phases of the heating device may include a pre-heating phase in which the aerosol-forming article or substrate has to be heated up from ambient temperature to a maintenance temperature during a given, relatively short time period. The maintenance temperature may be an elevated temperature in comparison to ambient temperature at which the aerosol-forming article or substrate has to be held or kept for the whole duration of the usage session. Additionally, boost phases of the heating device may also include heating the aerosol-forming article or substrate from the maintenance temperature up to an aerosolization temperature whenever a puff of the user is detected. During this heating on demand or flash-heating, aerosolization temperature has to be reached very quickly, because the puff of the user may typically last for a very short time and the temperature of the aerosol-forming article or substrate has to be increased very quickly to reliably form aerosol for consumption by the user during the puff. To fulfil the requirements of the heating device during boost phases, it may therefore be provided that the discharging circuit is configured to power the heating device in a boost phase in which a temperature of the heating device is increased.

[0039] For example during the boost phases of the heating device, it may be desirable to deliver the maximum power and / or voltage and / or current suppliable by the temporary energy storage to the heating device. However, routing the electrical energy supply through the discharging circuit may lead to losses and reduced efficiency that can be avoided. Therefore, there may be provided a first bypass circuit between the temporary energy storage and the heating device, wherein the first bypass circuit may be configured to bypass the discharging circuit and electrically connect the heating device to the temporary energy storage. Preferably, in this configuration, the heating device includes a resistive-type heater that can have a resistivity designed for being directly connected to the temporary energy storage via the first bypass circuit, without the need of any DC-DC conversion, or other electric conversion. The first bypass circuit may therefore be configured to directly connect the temporary energy storage to the heating device, circumventing the discharging circuit. The first bypass circuit may comprise a switch, for example a controlled switch controlled by the controller and / or processor of the aerosol-forming system, and otherwise may be or include a simple electrical line, therefore connecting the temporary energy storage and the heating device with minimal losses. Consequently, the temporary energy storage may be configured to power the heating device by the first bypass circuit in a boost phase, which may, for example, be controlled by the controller and / or processor.

[0040] During operation, the heating device may be supplied by the temporary energy storage either through the first bypass circuit or the discharging circuit as explained herein. However, to further shorten heating times and to increase the flexibility of the system, it may be desirable that the heating device may also be directly supplied with electrical energy by the removable energy storage. There may therefore be provided a second bypass circuit between the charging circuit and the heating device, wherein the second bypass circuit may be configured to bypass the discharging circuit as well as the temporary energy storage and electrically connect the heating device to the charging circuit and / or the removable energy storage. In this way, the heating device may be supplied with power and / or voltage and / or current directly from the charging circuit and / or the removable energy storage, circumventing both the temporary energy storage and the discharging circuit. This may enable two further modes of operation: During peaks of required power at the heating device, for example during the boost phases, the heating device may be supplied both by the temporary energy storage, either through the discharging circuit or through the first bypass circuit, and the removable energy storage through the second bypass circuit. This may increase the power available at the heating device and may therefore shorten heating times. Additionally or alternatively, the heating device may be supplied by the removable energy storage through the second bypass circuit outside of the boost phases. For example, the heating device may be supplied by the removable energy storage through the second bypass circuit in the maintenance phase, during which the temperature of the heating device and thus the aerosolforming article or substrate only needs to be maintained or kept at the current level. The power and / or voltage and / or current suppliable by the removable energy storage may be sufficient for maintaining the heating device at the maintenance temperature, for example when the power requirements are below 1.5 W, preferably below 1 W. In particular, the heating chamber and / or heating device may be thermally isolated in relation to the outside environment such that the power and / or voltage and / or current suppliable by the removable energy storage is sufficient for maintaining the heating device at the maintenance temperature. Additionally or alternatively, the aerosol-forming article or substrate may be configured in shape and size, i.e. to have a sufficiently small volume, for the supply by the energy storage to be sufficient for maintaining the maintenance temperature. The charging circuit may therefore be configured to power the heating device by the second bypass circuit, for example in a maintenance phase, in which a temperature of the heating device is maintained. By powering the heating device at least partially or exclusively directly from the removable energy storage and not from the temporary energy storage during maintenance phases, the energy stored in the temporary energy storage is saved for boost phases. In this way, the energy stored in the temporary energy storage may, for example, be sufficient for longer or more than one usage session. Alternatively, temporary energy storages of smaller capacity and lower cost may be used. Whether the charging circuit is connected to the temporary energy storage or the heating device may be controlled through a selector switch, for example which may be a controlled switch controlled by the controller and / or processor of the aerosol-forming system.

[0041] In general, the heating device may comprise one or more heating elements. For example, the heating device may comprise a heating element configured to be in direct contact with the aerosol-forming article or substrate. In some cases, such a heating element may also be part of the aerosol-forming article or substrate itself and may therefore be arranged inside the aerosolforming article or substrate, for example as one or more susceptor elements or heating foils. For example, for e-vapor type devices, the heating element can be a coil or mesh or other resistive structure that is in thermal contact with a liquid transfer element, such as a wicking element. Another type of heating element that may be in contact with the substrate may also be provided as a heating blade configured to be inserted into the aerosol-forming article or substrate when the aerosol-forming article or substrate is inserted into the aerosol-forming device. In case of cylindrical or rod-shaped aerosol-forming articles or substrates, such a heating element may be provided or configured to contact the curved surface of the rod. In case of flat or rectangular parallelepiped-shaped, plate-shaped or cuboid-shaped aerosol-forming articles or substrates, such a heating element may be provided or configured to be substantially flat itself and to contact one of the opposing flat main surfaces of the plate. There may also be provided at least two heating elements, for example each one provided or configured to contact one of the opposing flat main surfaces of the plate. In addition to one or more heating elements configured to be in direct contact with the aerosol-forming article or substrate, the heating device may also comprise at least one additional heater, for example a convective heater or convective heating element configured to pre-heat the air in the airflow path of the aerosol-forming device before the air reaches the aerosol-forming article or substrate. In other words, with regard to the airflow direction inside the aerosol-forming device, the convective heating element may be arranged upstream of the aerosol-forming article or substrate.

[0042] Therefore, the heating device may include at least two heating elements, for example any two or more of the mentioned heating elements. In this case, it may be provided that the removable energy storage and the temporary energy storage supply electrical energy to different heating elements. For example, the discharging circuit and / or the temporary energy storage may be configured to power at least one heating element, and the charging circuit may be configured to power, for example simultaneously power, at least one other heating element. In a specific embodiment, for example, the discharging circuit and / or the temporary energy storage may be configured to power at least one convective heating element as explained above. Also, the charging circuit and / or the removable energy storage may be configured to power, for example simultaneously power, at least one heating element configured to contact, for example directly contact, the aerosol-forming article or substrate. It may be provided that the heating element powered by the charging circuit and / or the removable energy storage may be configured to maintain the temperature of the aerosol-forming article or substrate at the maintenance temperature. Conversely, the heating element powered by the discharging circuit and / or the temporary energy storage may be configured to increase the temperature of the aerosol-forming article or substrate from ambient temperature to the maintenance temperature and / or from the maintenance temperature to the aerosolization temperature. It may also be provided that at least one heating element configured to be in direct contact with the aerosol-forming article or substrate may be powered by the discharging circuit and / or the temporary energy storage in a pre-heating phase in which the temperature of the aerosol-forming article or substrate is increased from ambient temperature to maintenance temperature, but that the same at least one heating element configured to be in direct contact with the aerosol-forming article or substrate is then powered by the charging circuit and / or the removable energy storage during maintenance phases when the maintenance temperature of the aerosol-forming article or substrate is to be maintained.

[0043] In the aerosol-forming system as described herein, the availability of a usage session may be dependent on the availability of a sufficiently charged temporary energy storage. As one of the problems solved by the present invention lies within the fact that the removable energy storage may not be able to provide sufficient power and / or voltage and / or current for the provision of a usage session, it follows directly that charging of the temporary energy storage by the removable energy storage until a usage session may be provided takes more time than a typical usage session. Therefore, when the temporary energy storage is discharged during a usage session, the user has to wait a comparatively long time for the temporary energy storage to be recharged until another usage session may be provided. To shorten the waiting time and thereby to alleviate this problem, the temporary energy storage may include at least two or more than two supercapacitors connected in parallel between the charging circuit and the discharging circuit. In this way, the temporary energy storage may store at least twice or more electrical energy, which may then be sufficient for the provision of more than one usage session, for example back-to- back usage sessions.

[0044] To further reduce waiting times, the charging circuit may be configured to charge one of the at least two supercapacitors, while the discharging circuit is configured to simultaneously power the heating device by discharging another of the at least two supercapacitors. In other words, by using parallelly arranged supercapacitors, at least one of them may be charged from the removable energy storage by the charging circuit while one or more of the other supercapacitors are discharged to operate the heating device and to provide a usage session for the user. The parallelly arranged supercapacitors may be parallelly connected using one or more, for example two, switch circuits, which may be configured to selectively connect at least one of the supercapacitors to the charging circuit and / or at least one of the supercapacitors to the heating device. The selective connection through the switch circuits may be controlled by the controller and / or processor of the aerosol-forming system. By being able to charge at least one of the supercapacitors during a usage session, the waiting time of the user for another usage session is further shortened.

[0045] It is noted that the aerosol-forming system may be free of serially connected supercapacitors. Any of the supercapacitors mentioned herein may be or may comprise only one single supercapacitor and may not be put together by two or more supercapacitors or supercapacitor stages arranged or connected in series. While such as serial connection of supercapacitors or supercapacitor stages may increase storage capacity and / or output, it disproportionately increases complexity and cost of the system, making it unsuitable for small, lightweight and low-cost handheld devices like aerosol-forming systems.

[0046] As already mentioned, activation and / or operation of the heating device may be dependent on whether or not a user actually wants to use the aerosol-forming system, for example by puffing on the device. However, other usage indications indicating that the user wants to initiate a usage session of the aerosol-forming system may also be possible, for example by detecting an input signal or a change in the surrounding environment or a spatial orientation of the system. Any of these usage indications may be used to control the aerosol-forming system. For example, the system may comprise a controller and / or processor, wherein the controller and / or processor is configured to detect a usage indication, for example using at least one puff sensor, capacity sensor, voltage sensor, flow sensor, pressure sensor, anemometer, accelerometer, inertial measurement unit, motion sensor, a button, a user interface and / or light sensor, and upon detection of the usage indication, to enable the discharging circuit to power the heating device. Specifically, a pre-heating phase may be initiated upon detection of the usage indication, bringing the aerosol-forming system into condition for immediately starting a usage session upon the first puff of the user.

[0047] To reduce losses of electrical energy due to a slow discharge of the temporary energy storage and / or the removable energy storage when the heating device is not operated and / or the temporary energy storage is not charged, the temporary energy storage may be reversibly disconnected from the removable energy storage and / or the heating device. For example, there may be provided a first disconnect circuit between the energy storage compartment and the temporary energy storage, wherein the first disconnect circuit may be configured to reversibly disconnect the temporary energy storage from the energy storage compartment. The first disconnect circuit may be arranged between the energy storage compartment and the charging circuit or between the charging circuit and the temporary energy storage. Additionally or alternatively, there may be provided a second disconnect circuit between the temporary energy storage and the heating device, wherein the second disconnect circuit is configured to reversibly disconnect the temporary energy storage from the heating device. The second disconnect circuit may be arranged between the discharging circuit and the heating device or between the temporary energy storage and the discharging circuit. The first and / or the second disconnect circuit may be controlled by the controller and / or processor of the aerosol-forming system.

[0048] The first disconnect circuit may be configured to connect the temporary energy storage to the removable energy storage whenever charging is needed and may be configured to disconnect the temporary energy storage from the removable energy storage when no charging is necessary. In other words, the first disconnect circuit may be configured to disconnect the temporary energy storage when the temporary energy storage is substantially fully or fully charged and to connect the temporary energy storage when the temporary energy storage is below a charging threshold. The charging threshold may be between 1% and 50%, or between 5% and 30%, or between 10% and 20% of a nominal capacity and / or a maximum capacity of the temporary energy storage. The controller and / or processor of the aerosol-forming system may be configured to determine the charging state of the temporary energy storage, for example by determining its current capacity and / or voltage. Therefore, the controller and / or processor of the aerosol-forming system may be configured to connect or disconnect the temporary energy storage to the charging circuit as needed.

[0049] The second disconnect circuit may be configured to connect the temporary energy storage when the usage indication is detected and to disconnect the temporary energy storage in absence of the usage indication. In other words, the second disconnect circuit may be configured to only connect the temporary energy storage to the heating device whenever operation and / or activation of the heating device is necessary. This may prevent energy losses during times in which the user does not actively use the aerosol-forming system, i.e. does not start a usage session, and may therefore minimize necessary recharging events or replacements of the removable energy storage.

[0050] Apart from the components as explained above, the aerosol-forming system may comprise additional components, for example additional electrical components, such as sensors, communications devices, display devices, LEDs, loudspeakers etc. Any of the components of the aerosol-forming system as described herein may be supplied with electrical energy from the removable energy storage. The supply of electrical components of the aerosol-forming system apart from the temporary energy storage and the heating device by the removable energy storage may be achieved by additional circuitry which may circumvent the charging circuit, the temporary energy storage and the discharging circuit. In other words, there may be one or more separate supply circuits supplying electrical components of the aerosol-forming system with electrical energy from the removable energy storage. For example, the system may include a supply circuit, for example including a DC-DC converter, wherein the supply circuit may be configured to electrically connect a controller to the energy storage compartment. The supply circuit may be connected to the removable energy storage and / or the energy storage compartment in parallel to the charging circuit and the other components explained above. As the charging circuit may be configured to provide an output corresponding to the necessary input of the temporary energy storage, this output of the charging circuit may be unsuitable for supplying other electrical components. Therefore, the supply circuit may be provided, and may be configured to provide an output corresponding to the necessary input of the further components, for example the controller and / or processor of the aerosol-forming system.

[0051] For example, the aerosol-forming system may comprise a display device and / or one or more LEDs, which may be configured and / or used to indicate a charging progress of the one or more temporary energy storages of the aerosol-forming device, for example to the user. To this end, for instance, an LED indication, a percentage indication and / or an increasing chart, for example a bar chart and / or a pie chart may be used. Additionally or alternatively, the display device and / or the one or more LEDs may be configured and / or used to indicate the availability of at least one usage session or a number of available usage sessions when the charge of the temporary energy storage is sufficient for at least one usage session.

[0052] The aerosol-forming system may include an aerosol-forming device and a companion device configured to charge the aerosol-forming device with electrical energy. Not all of the components as described herein need to be arranged or comprised in the aerosol-forming device. To save space in and / or to be able to make the aerosol-forming device smaller, at least some of the components may be arranged in the companion device. The temporary energy storage, the discharging circuit and optionally the heater device may be arranged in the aerosol-forming device. As mentioned, the heater device may at least partly be arranged in the aerosol-forming article or substrate. However, the aerosol-forming device may comprise a heater power circuit configured to supply the heating device with electrical energy, particularly a heating device which may be part of the aerosol-forming article or substrate. The energy storage compartment or the energy storage compartment and the charging circuit may be arranged in the companion device. A connection between the energy storage compartment in the companion device and the charging circuit and the temporary energy storage in the aerosol-forming device or a connection between the charging circuit in the companion device and the temporary energy storage in the aerosolforming device may be established through electrical connectors of the companion device and the aerosol-forming device. For example, the electrical connection may be established whenever the aerosol-forming device is at least partly inserted into the companion device. The temporary energy storage in the aerosol-forming device may then be charged from the removable energy storage in the companion device. In this way, the aerosol-forming device may not need to comprise the removable energy storage and / or the charging circuit and may therefore be much smaller and handier than when the removable energy storage and / or the charging circuit are part of the aerosol-forming device itself.

[0053] Another possible way of saving space and / or of making the devices of the aerosol-forming systems smaller may be by providing the energy storage compartment and optionally the charging circuit as a separate device. For example, the energy storage compartment may be removably coupled or couplable to the aerosol-forming system. Alternatively, the energy storage compartment and the charging circuit may be removably coupled or couplable to the aerosolforming system. In other words, they may be removably coupled or couplable to the aerosolforming device and / or the companion device. The energy storage compartment, possibly together with the charging circuit, may therefore be provided as a separate, mobile device which may be coupled to the aerosol-forming device and / or the companion device as necessary. The aerosolforming device and / or the companion device may therefore be provided with electrical connectors configured to be connected to the energy storage compartment and / or the charging circuit.

[0054] The aerosol-forming system described herein may further include an aerosol-forming article or substrate, wherein the aerosol-forming system may be configured to form aerosol from the aerosol-forming article or substrate. The aerosol-forming article or substrate may be any of the articles or substrates as mentioned herein.

[0055] According to another aspect of the present invention, there is provided a method for powering a heating device in an aerosol-forming system, for example an aerosol-forming system according to some embodiments of the present invention, including: stepping up or stepping down an input voltage provided by a removable energy source, for example a battery using synchronous rectifier; charging a temporary energy storage, for example a supercapacitor, with the input voltage, the temporary energy storage not being a battery; stepping up or stepping down an output voltage of the temporary energy storage; and powering a heating device by the output voltage. All of the features, functions and advantages described for the aerosol-forming system according to the present disclosure are also applicable to the method and vice versa.

[0056] The method may include providing an audible, haptic and / or visible user feedback when the temporary energy storage is substantially fully or fully charged or discharged to between 1 % and 50%, or to between 5% and 30%, or to between 10% and 20% of a nominal capacity and / or a maximum capacity of the temporary energy storage. In this way, the user may be readily informed about the status of the temporary energy storage and the availability of a usage session.

[0057] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0058] Example 1. An aerosol-forming system including: an energy storage compartment configured to receive a removable energy storage, a temporary energy storage, for example the temporary energy storage not being a battery, a charging circuit, configured to electrically connect the temporary energy storage to the removable energy storage and configured to at least partially charge the temporary energy storage from the removable energy storage, for example the charging circuit comprising and / or using a synchronous rectifier, a heating device, and a discharging circuit, electrically connecting the heating device to the temporary energy storage, wherein the discharging circuit is configured to power the heating device.

[0059] Example 2. The aerosol-forming system according to Example 1 , wherein the discharging circuit is configured to at least partially discharge the temporary energy storage to power the heating device, for example by providing electric energy to the heating device.

[0060] Example 3. The aerosol-forming system according to any one of the previous Examples, wherein the temporary energy storage is configured to store at least 200 joules or at least 400 joules or at least 600 joules or at least 800 joules or at least 1000 joules.

[0061] Example 4. The aerosol-forming system according to any one of the previous Examples, wherein the temporary energy storage includes a supercapacitor, for example configured to provide a maximum voltage between 1.7 volts and 5 volts or between 1.7 volts and 4 volts. Example 5. The aerosol-forming system according to any one of the previous Examples, wherein the energy storage compartment is configured to receive a removable energy storage providing a nominal voltage of about 1 .5 volts or about 1 .2 volts.

[0062] Example 6. The aerosol-forming system according to any one of the previous Examples, wherein the energy storage compartment is configured to removably receive a battery, for example a rechargeable or non-rechargeable battery, for example exclusively one standard sized AA-type battery or exclusively one standard sized AAA-type battery or exclusively one standard sized C-type battery or exclusively one standard sized D-type battery.

[0063] Example 7. The aerosol-forming system according to any one of the previous Examples, wherein the charging circuit includes a first DC-DC converter, for example a buck-boost converter.

[0064] Example 8. The aerosol-forming system according to any one of the previous Examples, wherein the charging circuit is configured to step-down an output voltage to the temporary energy storage below the nominal voltage of the removable energy storage until 0 volts or close to 0 volts or to step-up the output voltage to the temporary energy storage to a maximum charging voltage and / or an operating voltage of the temporary energy storage.

[0065] Example 9. The aerosol-forming system according to any one of the previous Examples, wherein the discharging circuit is configured to provide a constant power output or a constant voltage or a constant current to the heating device, for example by discharging the temporary energy storage to a minimal non-zero operation voltage at which power delivery is still possible, for example wherein the minimal non-zero operation voltage is at least 5% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% of the nominal operating voltage of the temporary energy storage.

[0066] Example 10. The aerosol-forming system according to any one of the previous Examples, wherein the discharging circuit includes a second DC-DC converter, for example a buckboost converter.

[0067] Example 11. The aerosol-forming system according to any one of the previous Examples, wherein the discharging circuit is configured to step-down an output voltage of the temporary energy storage to the heating device below a maximum voltage and / or the operating voltage of the temporary energy storage or to step-up the output voltage of the temporary energy storage to the heating device, for example while the voltage of the temporary energy storage drops during the provision of electric energy from the temporary energy storage to the heating device.

[0068] Example 12. The aerosol-forming system according to any one of the previous Examples, wherein the charging circuit and / or the discharging circuit includes an active rectification element, for example a field-effect transistor, FET, for example a metal-oxide-semiconductor fieldeffect transistor, MOSFET.

[0069] Example 13. The aerosol-forming system according to any one of the previous Examples, wherein the discharging circuit is a pulse-width modulation, PWM, controlled switch.

[0070] Example 14. The aerosol-forming system according to any one of the previous Examples, wherein the charging circuit and / or the discharging circuit is configured to multiply an input voltage, for example wherein the charging circuit and / or the discharging circuit is configured as a voltage doubler or as a voltage tripler.

[0071] Example 15. The aerosol-forming system according to any one of the previous Examples, wherein the charging circuit and / or the discharging circuit includes a charge pump, for example a Dickson charge pump.

[0072] Example 16. The aerosol-forming system according to any one of the previous Examples, wherein the discharging circuit is configured to power the heating device in a boost phase in which a temperature of the heating device is increased.

[0073] Example 17. The aerosol-forming system according to any one of the previous Examples, further including: a first bypass circuit between the temporary energy storage and the heating device, wherein the first bypass circuit is configured to bypass the discharging circuit and electrically connect the heating device to the temporary energy storage, and / or a second bypass circuit between the charging circuit and the heating device, wherein the second bypass circuit is configured to bypass the discharging circuit as well as the temporary energy storage and electrically connect the heating device to the charging circuit.

[0074] Example 18. The aerosol-forming system according to the previous Example, wherein the temporary energy storage is configured to power the heating device by the first bypass circuit in a boost phase. Example 19. The aerosol-forming system according to any one of Examples 17-18, wherein the charging circuit is configured to power the heating device by the second bypass circuit, for example in a maintenance phase, in which a temperature of the heating device is maintained.

[0075] Example 20. The aerosol-forming system according to any one of the previous Examples, wherein the heating device includes at least two heating elements, wherein the discharging circuit and / or the temporary energy storage is configured to power at least one heating element, and wherein the charging circuit is configured to simultaneously power at least one other heating element.

[0076] Example 21. The aerosol-forming system according to any one of the previous Examples, wherein the temporary energy storage includes at least two supercapacitors connected in parallel between the charging circuit and the discharging circuit.

[0077] Example 22. The aerosol-forming system according to the previous Example, wherein the charging circuit is configured to charge one of the at least two supercapacitors, while the discharging circuit is configured to simultaneously power the heating device by discharging another of the at least two supercapacitors.

[0078] Example 23. The aerosol-forming system according to any one of the previous Examples, further including: a controller, wherein the controller is configured to detect a usage indication, for example using at least one puff sensor, capacity sensor, voltage sensor, flow sensor, pressure sensor, anemometer, accelerometer, inertial measurement unit, motion sensor, a button, a user interface and / or light sensor, and upon detection of the usage indication, to enable the discharging circuit to power the heating device.

[0079] Example 24. The aerosol-forming system according to any one of the previous Examples, further including: a first disconnect circuit between the energy storage compartment and the temporary energy storage, wherein the first disconnect circuit is configured to reversibly disconnect the temporary energy storage from the energy storage compartment, and / or a second disconnect circuit between the temporary energy storage and the heating device, wherein the second disconnect circuit is configured to reversibly disconnect the temporary energy storage from the heating device.

[0080] Example 25. The aerosol-forming system according to the previous Example, wherein the first disconnect circuit is arranged between the energy storage compartment and the charging circuit or between the charging circuit and the temporary energy storage, and / or wherein the second disconnect circuit is arranged between the discharging circuit and the heating device or between the temporary energy storage and the discharging circuit.

[0081] Example 26. The aerosol-forming system according to any one of Examples 24-25, wherein the first disconnect circuit is configured to disconnect the temporary energy storage when the temporary energy storage is substantially fully or fully charged and to connect the temporary energy storage when the temporary energy storage is below a charging threshold.

[0082] Example 27. The aerosol-forming system according to the previous Example, wherein the charging threshold is between 1% and 50%, or between 5% and 30%, or between 10% and 20% of a nominal capacity and / or a maximum capacity of the temporary energy storage.

[0083] Example 28. The aerosol-forming system according to Example 23 and any one of Examples 24-27, wherein the second disconnect circuit is configured to connect the temporary energy storage when the usage indication is detected and to disconnect the temporary energy storage in absence of the usage indication.

[0084] Example 29. The aerosol-forming system according to any one of the previous Examples, further including: a supply circuit, for example including a DC-DC converter, wherein the supply circuit is configured to electrically connect a controller to the energy storage compartment.

[0085] Example 30. The aerosol-forming system according to any one of the previous Examples, including: an aerosol-forming device and a companion device configured to charge the aerosolforming device with electrical energy, wherein the temporary energy storage, the discharging circuit and optionally the heater device are arranged in the aerosol-forming device, and wherein the energy storage compartment or the energy storage compartment and the charging circuit are arranged in the companion device.

[0086] Example 31. The aerosol-forming system according to any one of the previous Examples, wherein the energy storage compartment is removably coupled to the aerosol-forming system or the energy storage compartment and the charging circuit are removably coupled to the aerosol-forming system. Example 32. The aerosol-forming system according to any one of the previous Examples, further including: an aerosol-forming article or substrate, wherein the aerosol-forming system is configured to form aerosol from the aerosol-forming article or substrate.

[0087] Example 33. A method for powering a heating device in an aerosol-forming system, for example an aerosol-forming system according to any one of Examples 1 to 32, including: stepping up or stepping down an input voltage provided by a removable energy source, for example a battery, for example using a synchronous rectifier; charging a temporary energy storage, for example a supercapacitor, with the input voltage, the temporary energy storage not being a battery; stepping up or stepping down an output voltage of the temporary energy storage; and powering a heating device by the output voltage.

[0088] Example 34. The method according to the previous Example, further including: providing an audible, haptic and / or visible user feedback when the temporary energy storage is substantially fully or fully charged or discharged to between 1 % and 50%, or to between 5% and 30%, or to between 10% and 20% of a nominal capacity and / or a maximum capacity of the temporary energy storage.

[0089] Examples will now be further described with reference to the figures in which:

[0090] Figure 1 shows an aerosol-forming system comprising an aerosol-forming device and a companion device;

[0091] Figure 2 shows a possible arrangement of the electrical components of the aerosol-forming system;

[0092] Figure 3a shows a possible implementation of the charging circuit and / or discharging circuit;

[0093] Figure 3b shows another possible implementation of the charging circuit and / or discharging circuit;

[0094] Figure 4 shows a discharge profile of the temporary energy storage;

[0095] Figure 5 shows a charge profile of the temporary energy storage;

[0096] Figure 6 shows a possible arrangement of the electrical components of the aerosol-forming system including a bypass of the discharge circuit;

[0097] Figure 7 shows a possible arrangement of the electrical components of the aerosol-forming system including more than one parallelly arranged temporary energy storages;

[0098] Figure 8 shows a possible arrangement of the electrical components of the aerosol-forming system including a bypass of the temporary energy storage; and

[0099] Figure 9 shows a flowchart of the method.

[0100] The figures are schematic only and not to scale. Figure 1 shows an aerosol-forming or aerosol-generating system 1 for forming or generating aerosol, for example for consumption or inhalation by a user in one or more usage sessions. The system 1 may comprise at least one of an aerosol-forming device 2 for generating aerosol and a companion device 3 for at least partially receiving the aerosol-forming device 2. The companion device 3 may be a charging device for charging the aerosol-forming device 2 and / or a temporary energy storage 19 thereof.

[0101] The aerosol-forming device 2 may comprise a mouthpiece 4, through which a user may inhale aerosol provided by the aerosol-forming device 2 for consumption during a usage session. The mouthpiece 4 can be part of the aerosol-forming device 2, for example a fixed or removable mouthpiece, or can be part of an aerosol-forming article that can be removably inserted to device 2. The aerosol may be provided from an aerosol-forming article or substrate provided inside the aerosol-forming device 2 and therefore not visible in Figure 1 .

[0102] The aerosol-forming device 2 may further include processing circuitry or control circuitry with at least one controller 5 and one or more processors 6. For generating the aerosol during use or consumption of the aerosol-forming article, the aerosol-forming device 2 may comprise at least one heating device 21 comprising at least one heating element 7 (see Figure 2) for applying heat to at least a portion of the aerosol-forming article. It may also be possible that the aerosolforming article or substrate itself comprises at least one heating element, for example a susceptor element, resistive heating foil, etc. Instead of the heating element 7, other non-thermal heating devices may also be used to generate aerosol from the aerosol-forming article, for example vibrating devices, pressure release etc. The processing circuitry and / or the controller 5 and / or the processor 6 may be configured to control actuation, activation and / or deactivation of the heating device 21.

[0103] For powering the at least one heating device 21 with electrical power, the aerosol-forming device 2 may further comprise a removable energy storage 15, preferably in the form of a commercially available, standard battery, for storing electrical energy or power. In Figure 1 , both the aerosol-forming device 2 and the companion device 3 each comprise an energy storage 15 and the energy storage 15 is electrically and removably coupled to the respective device 2, 3. However, alternatively, only one of the aerosol-forming device 2 and the companion device 3 may comprise a removable energy storage 15. In particular, energy storage 15 may be removably couplable to the aerosol-forming device 2 and / or the companion device 3. In other words, energy storage 15 may be a replaceable or removable energy storage 15 or battery. The connection between the removable energy storage 15 and the devices 2, 3 may be configured so that the devices 2, 3 may be run by electrical energy provided by the removable energy storage 15. Additionally, the connection between the removable energy storage 15 and the aerosol-forming device 2 and / or the companion device 3 may be configured so that data may be transmitted between the processing circuitries of the aerosol-forming device 2 and / or the companion device 3 and the removable energy storage 15.

[0104] The aerosol-forming device 2 may further comprise at least one electrical connector 12 for coupling to a corresponding at least one electrical connector 13 of the companion device 3 and / or an electrical connector of an external power supply (not shown), e.g., a USB charger. For example, when the aerosol-forming device 2 is at least partially inserted into the opening 14 of the companion device 3, the one or more electrical connectors 12 of the aerosol-forming device 2 may be coupled with the one or more electrical connectors 13 of the companion device 3 to charge the at least one removable energy storage 15 and / or temporary energy storage 19 of the aerosol-forming device 2. The connectors 12, 13 can also be implemented wirelessly, e.g. by means of antennas configured to electromagnetically transfer energy to and / or towards each other.

[0105] The aerosol-forming device 2 may further comprise a communications arrangement 9 or communication circuitry 9 with one or more communications interfaces 10 for communicatively coupling the aerosol-forming device 2 with the companion device 3 or other devices, for example, via an Internet connection, a wireless LAN connection, a WiFi connection, a Bluetooth connection, a mobile phone network, a mobile data connection for example but not limited to a 3G / 4G / 5G connection, an edge connection, an LTE connection, a BUS connection, a wireless connection, a wired connection, an optical data connection such as but not limited to IrDa, a radio connection, a near field connection, and / or an loT connection.

[0106] The aerosol-forming device 2 may further comprise a data storage 11 or memory for storing information, program code or data. Data storage 11 may also store collected values of sensors and / or one or more mathematical functions or formulas, software and computer instructions that can be executed by the processing circuitry, particularly controller 5 and / or processor 6. One or more sensors 16 may be arranged on, at or in the aerosol-forming device 2 or the companion device 3 to collect data. One or more of the sensors 16 may for example be temperature sensors, strain sensors, accelerometers or any other suitable sensors.

[0107] The aerosol-forming device 2 may further comprise user interface components, for example comprising an input element or input device 8, for example in the form of a pushbutton or a capacitive button. The input device 8 may be used as a power button to activate or deactivate the heating element 7 or ultrasonic or other device for aerosol generation thereby to activate or deactivate the aerosol-forming device 2. Upon activation of the aerosol-forming device 2, the heating element 7 may be activated and heat may be applied to at least a part of the aerosolforming article, such that aerosol can be generated for consumption or inhalation by the user, for example in a usage session. The aerosol generating device 2 and / or the companion device 3 may each comprise one or more output elements, such as a display device 17 and / or one or more LEDs, for outputting a signal and / or displaying information to a user, for example a user interface such as a GUI, or haptic and acoustic data output devices. The display device 17 may be, for example, a touchscreen and may therefore be configured as both an output and an input element. For example, the display device 17 and / or the one or more LEDs may be configured and / or used to indicate a charging progress of the one or more temporary energy storages 19 of the aerosolforming device 2, for instance with an LED indication, a percentage indication and / or an increasing chart, for example a bar chart and / or a pie chart. For example, the display device 17 and / or the one or more LEDs may be configured and / or used to indicate the availability of at least one usage session or a number of available usage sessions when the charge of the temporary energy storage 19 is sufficient for at least one usage session.

[0108] The aerosol-forming device 2 and / or the companion device 3 may comprise an energy storage compartment 18 for removably receiving the removable energy storage 15. The energy storage compartment 18 may be configured in form, shape and / or size to receive a specific type of removable energy storage 15, for example one of the specific types of battery available in retail stores as explained herein. Further, the energy storage compartment 18 may comprise electrical contacts or leads which may be configured to electrically connect or couple the removable energy storage 15 to further components, for example electrical loads, of the aerosol-forming device 2 and / or the companion device 3.

[0109] For example, the removable energy storage 15 may be connected or coupled to a charging circuit 20. The charging circuit 20 may be configured to facilitate charging of the temporary energy storage 19 by the removable energy storage 15. For example, the charging circuit 20 may be configured to charge the temporary energy storage 19 by supplying power and / or voltage and / or current from the removable energy storage 15 to the temporary energy storage 19. Charging circuit 20 may therefore be designed, configured and / or implemented to provide temporary energy storage 19 with the power and / or voltage and / or current necessary to charge the temporary energy storage 19. The power and / or voltage and / or current necessary to charge the temporary energy storage 19 may change over time during charging of the temporary energy storage 19. Therefore, the charging circuit 20 may be configured to provide the optimal power and / or voltage and slid or current for charging the temporary energy storage 19 at any and / or all points or moments of the charging profile of the temporary energy storage 19. The charging circuit 20 may therefore be configured to step up or step down the power and / or voltage and / or current provided by the removable energy storage 15 depending on the requirements for charging the temporary energy storage 19.

[0110] In cases in which the aerosol-forming device 2 comprises the removable energy storage 15, charging of the temporary energy storage 19 may be performed between usage sessions, for example whenever there is no usage session underway. In cases in which the companion device 3 comprises the removable energy storage 15, charging of the temporary energy storage 19 may be performed whenever the aerosol-forming device 2 is inserted into the opening 14 of the companion device 3 and an electrical connection between the electrical connectors 12, 13 is established.

[0111] Although Figure 1 shows a case in which the companion device 3 comprises all of the removable energy storage 15, the energy storage compartment 18 and the charging circuit 20, the charging circuit 20 may also be provided exclusively on the aerosol-forming device 2. In other words, it may be provided that only the removable energy storage 15 and the energy storage compartment 18 are arranged or provided on the companion device 3 whereas at least the temporary energy storage 19 and the charging circuit 20 may be arranged or provided on the aerosol-forming device 2.

[0112] To be able to provide the heating device 21 , for example one or more heating elements 7 of the heating device 21 , with the power and / or voltage and / or current necessary for heating an aerosol-forming article or substrate, a discharging circuit 22 may be provided, which may electrically connect and / or couple the temporary energy storage 19 to the heating device 21 . The discharging circuit 22 may be configured to provide the heating device 21 with the power and / or voltage and / or current suitable are necessary for heating the aerosol-forming article or substrate by discharging the temporary energy storage 19. During discharge of the temporary energy storage 19, the power and / or voltage and / or current provided or providable by the temporary energy storage 19 may change. The discharging circuit 22 may therefore be configured to step up or step down the power and / or voltage and / or current provided by the temporary energy storage 19 depending on the requirements for heating the heating device 21 , particularly one or more heating elements 7.

[0113] Figure 2 shows a first possible implementation of the electrical arrangement of the aerosolforming system 1 according to at least some aspects of the present invention. As already mentioned, the energy storage compartment 18 as well as the removable energy storage 15 and the charging circuit 20 or the energy storage compartment 18 and the removable energy storage 15 may be arranged in the companion device 3 while the rest of the shown components may be arranged in the aerosol-forming device 2. Also, the energy storage compartment 18, and with it the removable energy storage 15 if present, and optionally the charging circuit 20 may be removably coupled to the companion device 3 and / or the aerosol-forming device 2. This is true for all embodiments described herein and will not be mentioned again.

[0114] The aerosol-forming system 1 , as schematically illustrated in Figure 2, may include an energy storage compartment 18 configured to removably hold a removable energy storage 15, for example a replaceable and standard battery, for example one of a C-type, D-type, AA-type, or an AAA-type. It may further include a charging circuit 20, for example a first DC-DC converter 24, configured to charge the temporary energy storage 19. The temporary energy storage 19 may be of any type as explained herein, and may for example be a supercapacitor 23. The aerosolforming system 1 may further comprise a discharging circuit 22, for example a second DC-DC converter 25, configured to discharge the temporary energy storage 19 in a controlled way to provide for a stabilized voltage or specific voltage level to a heater power circuit 33 or directly to a heating device 21. The heater power circuit 33 may be an optional component and may be configured to provide the heating device 21 and / or the heating elements 7 with electrical energy from the temporary energy storage 19, for example by the discharging circuit 22. Optionally, the system 1 may include a heating cavity and one or more heating elements 7 of the heating device 21 , for example in the heating cavity, into which an aerosol-forming article or substrate 37 may be removably inserted. As a variant, for example for e-vapor type products, the aerosol-forming article or substrate 37 may be a removable cartridge or pod having the heating device 21 or at least one heating element 7 therein. The heater power circuit 33 may be part of the system 1 and may be removably interconnectable to the aerosol-forming article or substrate 37.

[0115] The controller 5 and / or the processor 6 may be configured and / or arranged to control the various elements of the system 1 , for example in operative connection with various sensors 16. For example, the controller 5 and / or the processor 6 may be configured to control the charging circuit 20 and / or the discharging circuit 22. Particularly, the controller 5 and / or the processor 6 may be configured to control the charging circuit 20 to provide the temporary energy storage 19 with an appropriate charging power and / or voltage and / or current. For this, the controller 5 and / or the processor 6 may be configured to sense and / or determine the charging and / or discharging status, for example the output power and / or the output voltage and / or the output current, of the removable energy storage 15, for example by a connection to the electrical connectors or pins or leads of the energy storage compartment 18. The controller 5 and / or the processor 6 may also be configured to sense and / or determine the charging status of the temporary energy storage 19, for example a voltage and / or capacity of the temporary energy storage 19. Additionally or alternatively, the controller 5 and / or the processor 6 may be configured to control the discharging circuit 22 to provide the heating device 21 and / or the heater power circuit 33 with an appropriate heating power and / or voltage and / or current. For this, the controller 5 and / or the processor 6 may be configured to sense and / or determine the output power and / or output voltage and / or output current of the discharging circuit 22.

[0116] Heater power circuit 33 may be implemented in different ways. In one possible embodiments, heater power circuit 33 may be implemented as a transistor or switch that can operate in an on-off fashion or pulse-width modulation (PWM) fashion, for example controlled by the controller 5 and / or the processor 6, to apply the current from the output capacitor of second DC-DC converter 25 to a resistive heater load, for example a wick-and coil resistive heater, a substrate-penetrating heater such as a blade, bolt, or pin acting as an internal heater, or an external tubular resistive heater comprised in the heating device 21. More complex heater power circuits 33 are also possible, for example an oscillator for providing an alternating magnetic field with an inductive heater coil for inductive heating via a susceptor, or an oscillator for providing an alternating electric field between electrode plates forming a capacitor for dielectric heating of the substrate.

[0117] Figure 3a shows a possible implementation of the charging circuit 20, particularly as the first DC-DC converter 24. The charging circuit 20 may use a synchronous rectifier to charge the temporary energy storage 19. The synchronous rectifier may be part of or comprised by the first DC-DC converter 24. As schematically shown, the first DC-DC converter 24 may be configured as a buck-boost converter or step-up and step-down converter, so that the output voltage over the temporary energy storage 19, exemplarily shown here as supercapacitor 23, may be below the voltage of the removable energy storage 15 (for example from 1.2 V to 1.5 V), optionally even down to zero, but eventually may be boosted past the voltage of the removable energy storage 15 to reach the maximum charging and operating voltage of the supercapacitor 23, for example in a range between 2 V to 4 V. In an embodiment, the first DC-DC converter 24 may be configured with active or synchronous rectification (SR) using switched transistors T1 , T2 in a synchronous diode (SD) configuration, instead of freewheeling diodes. Further elements are synchronous diodes or active rectification elements 26 and inductor L. The transistors T1 , T2 and synchronous diodes or active rectification elements 26 may be controlled by the controller 5 and / or the processor 6. Controller 5 and / or processor 6 may also be configured to sense or determine the status of these elements. The shown arrangement may allow to minimize losses to avoid the relatively high voltage drop over the diodes in comparison to the low battery supply voltage, to strongly improve efficiency.

[0118] The illustration in Figure 3a shows a non-inverting synchronously rectifying buck-boost converter, that can be used for the charging circuit 20, i.e. the first DC-DC converter 24, between the energy storage compartment 18 and temporary energy storage 19, i.e. supercapacitor 23. As an alternative, also an inverting synchronously rectifying buck-boost converter could be used. The same configuration may also be used for the discharging circuit 22, i.e. the second DC-DC converter 25, between the temporary energy storage 19, i.e. supercapacitor 23, and the heating device 21 and / or the heater power circuit 33. In this case, the removable energy storage 15 of Figure 3a would be replaced by the temporary energy storage 19, i.e. supercapacitor 23, and the supercapacitor 23 would be replaced by the heating device 21 and / or the heater power circuit 33. The other components may remain the same. The discharging circuit 22, i.e. the second DC-DC converter 25, may in this way provide for a stabilized voltage output for the heater power circuit 33 and / or the heating device 21 , but may also be implemented differently. For example, it may be provided that the second DC-DC converter 25 is a pulse-width modulation (PWM) controlled switch to apply voltage pulses from the temporary energy storage 19 to the heating device 21 , for example at least one heating element 7, for example a resistive heating element 7 having a specific resistive value. Upon decrease of the voltage over temporary energy storage 19, to maintain a specific heating power, the pulse widths may be lengthened in duration. In such a configuration, no separate heater power circuit 33 may be necessary and may therefore be dispensed with. The heating device 21 may therefore be directly connected to the discharging circuit 22 without interposing any other circuits, for example heater power circuit 33.

[0119] In a variant, as schematically shown in Figure 3b, the first DC-DC converter 24 and / or the second DC-DC converter 25 may be embodied as a charge-pump circuit 27 or a combination of buck-boost and charge-pump circuits 27, for example as Dickson multipliers. For example, the first DC-DC converter 24 may be configured as a voltage multiplier, for instance a voltage doubler or voltage tripler. It may be configured to multiply voltage in a step-wise manner by successively transferring charge between capacitors. For example, the first DC-DC converter 24 and / or the second DC-DC converter 25 may comprise two multiplication steps, as shown in Figure 3b. This may be used for a 1 .5 V single standard battery to reach voltages of 3 V or 4.5 V for charging the temporary energy storage 19. For example, the DC-DC converters 24, 25 that may be implemented with and / or as charge pump circuits 27 may use diode-connected field-effect- transistors (FET) as active rectification elements 26 instead of diodes, which may be wired to act as diodes, to reduce the diode voltage drop for improved efficiency. In addition, additional FETs, for example metal-oxide-semiconductor field-effect transistors (MOSFETs) M, may be arranged in parallel to the diode-connected FETs. Clock signals or pulse signals q>i, q>2, may be provided by the controller 5 and / or the processor 6 and may be connected to the charge-pump circuit 27 through capacitors 38.

[0120] In practice, when the charging circuit 20 is implemented as charge-pump circuit 27, the energy storage compartment 18, and thereby the removable energy storage 15, may be connected to the charge-pump circuit 27 at VIN. The temporary energy storage 19 may be connected to the charge-pump circuit 27 at VOUT. Conversely, when the discharging circuit 22 is implemented as charge-pump circuit 27, the temporary energy storage 19 may be connected to the charge-pump circuit 27 at VIN. The heating device 21 and / or the heater power circuit 33 may be connected to the charge-pump circuit 27 at OUT.

[0121] Figure 4 shows a discharge profile of the temporary energy storage 19, specifically a supercapacitor 23. During the discharge of the supercapacitor 23, for example for heating the heating device 21 , the voltage V of the supercapacitor 23 drops, while the current A output from the supercapacitor 23 increases. This voltage V and current A is provided as input for the discharge circuit 22 or second DC-DC converter 25. To maximize the use of electric energy stored in the supercapacitor 23, the discharge circuit 22 or second DC-DC converter 25 may be configured to have an input voltage range from the maximum discharge voltage of the supercapacitor 23 to close to zero volt, and may for example provide for a constant voltage at the output of the discharge circuit 22 or second DC-DC converter 25. This may allow to substantially discharge all electrical energy stored in the supercapacitor 23 to provide it to the heating device 21 . In this respect, the voltage V of the supercapacitor 23 may approximately linearly decrease if a linearly increasing current is drawn from the supercapacitor 23 to provide for constant power. The discharge may be stopped when voltage V is at or below 5 % to 25 % of the nominal voltage of the supercapacitor 23, to avoid excessive currents A. As shown in Figure 4, the current A may increase abruptly at low voltages V, which may be stressful or even harmful for the further components. A controlled stop of the discharge at the mentioned threshold may therefore be beneficial for increased device lifetime. The discharge may be controlled and therefore also stopped by the controller 5 and / or the processor 6.

[0122] Figure 5 shows a charging profile of the temporary energy storage 19, specifically a supercapacitor 23. During the charging of the supercapacitor 23 from the removable energy storage 15, the voltage V’ of the supercapacitor 23 may increase linearly when the charging current A’ output from the removable energy storage 15 is kept constant. The charging circuit 20 or the first DC-DC converter 24 may be configured to provide the temporary energy storage 19 or supercapacitor 23 with the constant current A’ from the energy storage compartment 18 and the removable energy storage 15. The charging time used for charging the temporary energy storage 19 from the removable energy storage 15 may be longer than the typical duration of a puff of a user on the aerosol-forming device 2, which may, for example, be between 0.5 seconds and 5 seconds. The temporary energy storage 19 may then be configured to provide the accumulated power for heating the heating device 21 during a puff and / or a usage session at power levels unattainable by the removable energy storage 15.

[0123] Turning now to Figure 6, several optional further features of the aerosol-forming system 1 according to aspects of the present invention are shown. For example, there may be provided a first disconnect circuit 30 or disconnect switch associated with the charging circuit 20 or first DC- DC converter 24. The first disconnect circuit 30 may be arranged between the charging circuit 20 or first DC-DC converter 24 and the temporary energy storage 19. Additionally or alternatively, there may be provided a second disconnect circuit 31 or disconnect switch associated with the discharging circuit 22 or second DC-DC converter 25. The second disconnect circuit 31 may be arranged between the discharging circuit 22 or second DC-DC converter 25 and the temporary energy storage 19. The first disconnect circuit 30 and the second disconnect circuit 31 may be controlled by the controller 5 and / or the processor 6. In this way, the temporary energy storage 19 or supercapacitor 23 may be electrically isolated from either or both circuits 20, 22, to avoid or reduce power consumption during certain time periods. For example, when the charging circuit 20 or first DC-DC converter 24 charges the temporary energy storage 19 or supercapacitor 23, the discharging circuit 22 or second DC-DC converter 25 may be disconnected from the temporary energy storage 19. Also, when the temporary energy storage 19 is fully charged, but no heating is performed, both circuits 20, 22, i.e. first and second DC-DC converters 24, 25, may be disconnected from temporary energy storage 19. Once a signal indicative of a usage session and / or puff is received, the discharging circuit 22 or second DC-DC converter 25 may be connected to the temporary energy storage 19 to provide electrical energy to the heating device 21. This may allow to preserve the energy in the charged temporary energy storage 19 for heating operations, in particular during longer periods where the aerosol-forming device 2 is not used, so that the charged temporary energy storage 19 or supercapacitor 23 can readily provide for heating energy.

[0124] For example, the signal indicative of a heating session, usage session, and / or a puff may be generated by a sensing device or sensor 16 that is an element of the aerosol-forming device 2, for example a puff sensor 36, for example but not limited to a pressure sensor, flow sensor, anemometer, an accelerometer or inertial measurement unit (I MU) that may detect motion as a signal indicative of an imminent heating session, a sensor detecting the insertion of an aerosolforming article or substrate 37 into device 2, for example the insertion of a cartridge, pod, substrate, heat-not-burn (HnB) stick, or a sensor that can detect the opening of a lid that closes the heating cavity. Such signal may prompt the controller 5 and / or the processor 6 to first reconnect the temporary energy storage 19 to the discharging circuit 22, and thereafter start heating by the heating device 21. In a variant, the sensing device may include a push button or other input device 8 or user interface element that may be actuated by a user to manually indicate the initiation of a usage session or puff.

[0125] As also shown in Figure 6, there may be provided a bypass switch or circuit 28 that may allow to short-circuit the temporary energy storage 19 or supercapacitor 23 to the heating device 21 , for example when the heating device 21 comprises at least one resistive heating element 7. The bypass switch 28 may be arranged in parallel to the discharging circuit 22 or second DC-DC converter 25, or may be arranged to bypass the inductor L of the second DC-DC converter 25. Alternatively, the bypass switch on circuit 28 may be part of the second DC-DC converter 25 itself which may be in an on-state to have 100% duty cycle, and can be used for example for a heatup phase for a HnB substrate, and may be in an off-state to have 0% or close to 0% duty cycle. This may allow to maximize a power delivery to the heating device 21 , to thereby shorten the waiting time for heating up the substrate. The resistive value of the resistive heating element 7 may be designed such that a safe continuous current is being pulled from the temporary energy storage 19 or supercapacitor 23 despite direct connection to the heating device 21. As a non- limiting example, the supercapacitor 23 may be charged to 3 V, and a maximum current of 7 A or a maximum continuous current of 7 A may be pulled from supercapacitor 23, permitting to generate 21 W of heating power, which may exceed the heating power that may be provided by most HnB devices. Thereby, the resistance value of the resistive heating element 7 may be designed to have the appropriate resistance value so that no other current limiter is needed, e.g. 0.429 Ohm for the above example.

[0126] In Figure 7, an embodiment is shown in which two temporary energy storages 19 or supercapacitors 23 are provided in parallel. In principle, more than two parallelly arranged temporary energy storages 19 may also be used. However, it is noted that some aspects may only pertain to a single temporary energy storage 19 or supercapacitor 23 used in series. In other words, the aerosol-forming system 1 may be free of temporary energy storages 19 or supercapacitors 23 arranged in series to each other.

[0127] The two temporary energy storages 19 or supercapacitors 23 of Figure 7 arranged in parallel may be arranged between first switch circuit 34 and second switch circuit 35. For example, first switch circuit 34 may be a 1 :2 demultiplexer switch, while the second switch circuit 35 may be a 2:1 multiplexer switch. The first and second switch circuits 34, 35 may be or may comprise latching relays to minimize on-state power losses, as there may be only few switching instances, e.g. once every 3-10 minutes, but long on-state durations, e.g. up to 6-8 minutes. The two temporary energy storages 19 arranged in parallel may be used to avoid that the user has to wait for a temporary energy storage 19 or supercapacitor 23 being fully or substantially charged. For example, it may be provided that one temporary energy storage 19 is charged while the other one is used for discharging and powering the heating device 21 . Upon start-up of the aerosol-forming device 2 or during idle periods, it may be provided that the controller 5 and / or processor 6 controls sequential charging of both first and second temporary energy storages 19 one after the other, so that double the stored energy may be available for aerosol generation. This may allow to provide for two consecutive usage sessions by the aerosol-forming device 2. By optionally providing three or more temporary energy storages 19 or supercapacitors 23 arranged in parallel, waiting time between user sessions may be shortened even further.

[0128] Figure 8 also shows further possible features for the embodiments according to the aspects of the present invention. Specifically, in the arrangement of Figure 8, both the charged temporary energy storage 19 and the removable energy storage 15 may provide energy simultaneously to the heating device 21 , for example to power two separate heating elements 7 of the heating device 21 . To achieve this, a selector switch 29 may be provided between the charging circuit 20, the temporary energy storage 19 and at least one of the heating elements 7 of the heating device 21. Selector switch 29 may be controlled by controller 5 and / or processor 6, for example to first charge the temporary energy storage 19 via the removable energy storage 15 using the charging circuit 20, and may thereafter be controlled to selectively deliver energy to heating device 21 by the charging circuit 20.

[0129] Given the continuous power limitations of the removable energy storage 15 versus continuous power delivery from temporary energy storage 19 that may be in a range of a factor 5 to 20 superior, for example in a range of a factor of 10 to 15, the lower electric energy of removable energy storage 15 may be used for heating a substrate of aerosol-forming article or substrate 37 during or in a maintenance heating phase, whereas the electric energy of temporary energy storage 19 may be used for a pre-heating phase or an instantaneous / boost mode phase, for example during a puff. A maintenance heating phase or maintenance heating may describe that the temperature of the aerosol-forming article or substrate 37 has to be held at an elevated temperature when compared to ambient temperature. This maintenance heating may need to be maintained during the whole usage session, but the temperature at which the aerosol-article or substrate 37 has to be held may be smaller than during a puff. A pre-heating phase or pre-heating may describe the phase in which the aerosol-forming article or substrate 37 has to be heated up from ambient temperature to the maintenance temperature. This is typically done in a very short time and may therefore use a lot of power. Also, and instantaneous / boost mode phase or instantaneous / boost mode heating may mean that the aerosol-forming article or substrate 37 has to be heated up from the maintenance temperature to aerosolization temperature, which may be higher than the maintenance temperature. This is typically done on demand whenever a puff of a user is detected and therefore needs to be very quick, which also necessitates a lot of power in a very short time.

[0130] Generally, the power requirements for maintenance heating may be much lower as compared to boost / instantaneous heating, so that the removable energy storage 15 may be able and may be controlled to provide for the electric energy solely during the maintenance heating phase. In a typical heating session, about 20-40% of the heating power may be used for the heatup or pre-heating phase, while the rest may be used for the remaining usage session. In addition, if the heating device 21 is powered by energy from the temporary energy storage 19 solely during the puff time of the maintenance heating phase, the power needed for the maintenance heating phase would be even lower, such that the electric energy provided by the removable energy storage 15 may be sufficient. This may allow to reduce the electrical energy that has to be provided by the temporary energy storage 19, so that a smaller capacitance supercapacitor 23 may be implemented, for example one that can store less than 500 Joules, preferably less than 400 Joules, while still allowing the provision of a usage session of appropriate duration, for example having a duration of 180-360 seconds.

[0131] In the embodiment shown in Figure 8, an external heating element 7 may be provided as an exemplary heating unit providing for the maintenance heat, and an upstream convective heating element 39 may be provided for the boost / instantaneous heat. The upstream convective heating element 39 may be configured to pre-heat and airflow through the aerosol-forming device 2 upstream of the aerosol-forming article or substrate 37. The term “upstream” may pertain to the direction of airflow in the aerosol-forming device 2. During a pre-heat phase, external heating element 7 may be connected to the output of the discharging circuit 22 or directly to the temporary energy storage 19 (as shown in Figure 6) for the power-intensive heat-up phase. Next, during the usage session, the removable energy storage 15 may be used to power the external heating element 7 for the maintenance heat, via the charging circuit 20 and the selector switch 29, while the temporary energy storage 19 may be used to power the convective heating element 39 via the discharging circuit 22. As the puff duration may be relatively short as compared to the entire heating session or usage session, and due to thermal inertia and thermal insulation of the heating chamber of device 2, it may be possible to turn-off the maintenance heat by external heating element 7 whilst heating the incoming air from the puff with upstream convective heating element 39. The aerosol-forming device 2 may therefore be configured to exclusively heat the external heating element 7 during a maintenance phase and to exclusively heat the convective heating element 39 during a puff.

[0132] Figure 8 also shows that optionally, an additional supply circuit 32, for example comprising another DC-DC converter, may be provided for the supply voltage for the controller 5 and / or the processor 6 and for other electronics required to control operation of or comprised in the aerosolforming device 2, separate from the charging circuit 20 and discharging circuit 22 for the power delivery to heating device 21. The power supply for the control electronics (e.g. controller 5, processor 6, sensor 16, puff sensor 36, etc.) may not be powered by energy from the temporary energy storage 19, but may be provided with a separate power supply from the removable energy storage 15, for example via a separate step-up DC-DC converter connected to energy storage compartment 18 and removable energy storage 15 providing one or more of 2.7 V, 3.3 V, 5 V, or other voltage levels for operation of control electronics.

[0133] Figure 9 shows a flowchart of method 40 according to an aspect of the present invention. First, a removable energy storage 15, for example a battery may be inserted into the energy storage compartment 18 of the aerosol-forming device 2. Next, the charging circuit 20, for example the first DC-DC converter 24, is used to charge the temporary energy storage 19, for example the supercapacitor 23, from electric energy provided by the removable energy storage 15. To achieve this, the input voltage of the removable energy storage 15 provided through the energy storage compartment 18 may be stepped up or stepped down by the charging circuit 20, as shown in step 41 . This input voltage stepped up or stepped down by the charging circuit 20 is then used to charge the temporary energy storage 19, as indicated in step 42. During the charging time, I user feedback that the temporary energy storage 19 is being charged may be provided, as shown in step 43. For example, a user interface may optionally indicate that the temporary energy storage 19 is being charged and / or may indicate a charging state, for example by illuminating an LED light. During this charge phase, the voltage across the supercapacitor 40 may increase from substantially 0 volts or from a discharge threshold as described above, up to the maximum operation voltage.

[0134] Next, upon fully or substantially fully charging the temporary energy storage 19, the aerosolforming device 2 may change to a ready state, where the user can start a usage session. This may be indicated to the user via the user interface, for example by illuminating an LED light. Next, a user may initiate a usage session to switch the aerosol-forming device 2 to a usage state, for example by pressing a button, an insertion of an aerosol-forming article or substrate 37 into the heating chamber, detecting a puff by a user by the puff sensor 36, or by another action. At this stage, the discharging circuit 22, for example the second DC-DC converter 25, may discharge the temporary energy storage 19 to provide energy to heater power circuit 33 and heating device 21 . For this, the output voltage of the temporary energy storage 19 may be stepped up or stepped down by the discharging circuit 22, as indicated in step 44. The output voltage stepped up or stepped down by the discharging circuit 22 in this way is then used for powering the heating device 21 , either directly or through the heater power circuit 33, as indicated in step 45.

[0135] During the discharge, the voltage across the temporary energy storage 19 may drop progressively as the electric energy from the temporary energy storage 19 is depleted, and the discharging circuit 22 may be configured to provide a predetermined power flow from the temporary energy storage 19 to the heater power circuit 33 and / or the heating device 21 despite the constant drop in voltage across the temporary energy storage 19. This may be achieved by controlling the output voltage of the discharging circuit 22 to a desired voltage level, for example a DC voltage across an output capacitor or input capacitor of heater power circuit 33. In other words, the discharging circuit 22 may be configured to receive input wattages from the temporary energy storage 19 at least between the maximum charged voltage of the temporary energy storage 19 to close to zero voltage or zero voltage, thereby being able to handle increasing currents with the decreasing voltage.

[0136] As soon as the usage session is close to the end, for example after a certain amount of energy has been depleted from the temporary energy storage 19, for example up to a predefined threshold of, for example 80% or 85% or 90% or 95% of the maximum nominal capacity of the temporary energy storage 19, user feedback may again be provided as indicated in step 46. The user may again be notified by the user interface, for example by a blinking LED, a vibratory signal, an icon on a display screen, a change of color, etc. Furthermore, the user may additionally also be notified about the charging progress and / or the charging status of the temporary energy storage 19, for instance by the display device. This may be implemented using an LED indication, an increasing chart, such as a bar chart and / or a pie chart, or by other suitable information output means and / or elements. Upon reaching full discharge of the temporary energy storage 19, the user interface may also notify the user. The user may then manually trigger the recharging of the temporary energy storage 19 by the charging circuit 20 to go to the charging state, or this may be done automatically after depletion, for example controlled by the controller 5 and / or processor 6.

[0137] Taking an HnB device as a non-limiting example, a removable, standard AA battery may be used as removable energy storage 15, having a safe long-term allowable discharge current of 1 A, and a voltage of 1.5 V. Therefore, an instantaneous power that may be pulled from such exemplary battery should not exceed 1.5 W. Also, as an example, the energy stored in the AA battery can be assumed to be about 4 Wh, which is 14,400 Joules of energy. A supercapacitor 23 may be chosen to have about 110 F capacity, 3.2 V maximum voltage, and be configured to store about 500 Joules of energy, corresponding to 500 Ws, 8.33 Wmin, or 0.134 Wh. In particular, a supercapacitor 23 may be chosen that has an energy storage capability of 250 to 1000 joules of energy, with a nominal voltage above 2.5 V, for example above 2.8 V. This energy may be used to power one heating session or usage session of the aerosol-forming device 2 in a heat-not-burn application, for example having a duration of 180-360 seconds. In terms of instantaneous power, the maximum safe continuous current that may be pulled from this exemplary supercapacitor 23 is about 6.3 A, while bursts of current for one second can be up to 60 A, which results in a continuous instantaneous power of about 20 Watts, for example by the bypass circuit 28. In an exemplary operation, the heating session of the heat-not-burn device may use a start-up heating power of 10 Watts during 30 seconds, or more with a boost phase, and then may require about 1 W to 2.5 W of heating power during the steady heating phase where the user is able to take puffs, for example for 300 seconds or 5 minutes.

[0138] As can be readily seen from this example, the AA battery may theoretically provide energy for 28.8 usage sessions of 500 Joules each, assuming for simplicity that there are no other power losses, or at least 20 usage sessions assuming 30% overall system losses, for example for data processing, power switching losses, etc. However, in terms of instantaneous power from an AA battery, the maximum instantaneous power is maximally 1.5 W, so generally more power may be needed for the steady heating phase, and 6.67 times would be needed for the power for the heatup phase. Hence, with the given example using the supercapacitor 23, which can provide for 20 W continuous instantaneous power, there are no power limitations. If the supercapacitor 23 is charged by the battery via the first DC-DC converter, it may take about 333 seconds or 5.55 minutes to fully charge the supercapacitor 23 to 500 J at a charging power of 1.5W. Given the power losses and other limitations that may be imposed to avoid excessive temperature due to DC-DC converter switching losses, the recharge time of the supercapacitor 23 may be close to 10 minutes. By having two, or even three supercapacitors 23 arranged in parallel as described before, the recharge time may be reduced, for example halved.

[0139] Taking a puff-on-demand or e-vapor device as another non-limiting example, an exemplary supercapacitor 23 may be used that has 110 F capacity, 3.2 V maximum voltage, and that is configured to store about 500 Joules of energy, as with the HnB example. This energy may provide about 20 puffs for a puff-on demand e-vapor type aerosol-forming device 2, assuming that each puff would consume about 25 Joules, for example a puff having a duration of 2 seconds at a power of 12.5 Watts each. As most e-vapor devices use a simple resistive heater with an exemplary resistance of about 1 Ohm, to generate a puff with an exemplary heating power of about 20 W, the voltage applied to the heating resistor needs to be about 4.47 V to generate a heating current of 4.47 A. The second DC-DC converter 25 could be directly connected to the heating device 21 to provide for electrical energy to the heater, or a heater power circuit 33 could be used.

[0140] In summary, therefore, according to at least some aspects of the present invention, an aerosol-forming system 1 is provided that may be powered by a standard retail replaceable and removable energy storage or battery. The aerosol-forming system 1 itself therefore may be free of a battery and typical battery chemicals. This allows to prolong the lifetime of the aerosol-forming system 1 as well as reduce its environmental footprint, and also provide for a convenient way for the user to replace the removable energy storage based on readily and common available retail batteries, thereby avoid the need of recharging the removable energy storage.

[0141] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10 % of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

CLAIMS1. An aerosol-forming system including: an energy storage compartment configured to receive a removable energy storage, a temporary energy storage, the temporary energy storage not being a battery, a charging circuit, configured to electrically connect the temporary energy storage to the removable energy storage and configured to at least partially charge the temporary energy storage from the removable energy storage, the charging circuit using a synchronous rectifier, a heating device, and a discharging circuit, electrically connecting the heating device to the temporary energy storage, wherein the discharging circuit is configured to power the heating device.

2. The aerosol-forming system according to claim 1 , wherein the temporary energy storage is configured to store at least 200 joules or at least 400 joules or at least 600 joules or at least 800 joules or at least 1000 joules.

3. The aerosol-forming system according to any one of the previous claims, wherein the temporary energy storage includes a supercapacitor, for example configured to provide a maximum voltage between 1.7 volts and 5 volts or between 1.7 volts and 4 volts.

4. The aerosol-forming system according to any one of the previous claims, wherein the energy storage compartment is configured to receive a removable energy storage providing a nominal voltage of about 1 .5 volts or about 1 .2 volts.

5. The aerosol-forming system according to any one of the previous claims, wherein the energy storage compartment is configured to removably receive a battery, for example a rechargeable or non-rechargeable battery, for example exclusively one standard sized AA-type battery or exclusively one standard sized AAA-type battery or exclusively one standard sized C-type battery or exclusively one standard sized D-type battery.

6. The aerosol-forming system according to any one of the previous claims, wherein the charging circuit is configured to step-down an output voltage to the temporary energy storage below the nominal voltage of the removable energy storage until 0 volts or close to 0 volts or to step-up the output voltage to the temporary energy storage to a maximum charging voltage and / or an operating voltage of the temporary energy storage.

7. The aerosol-forming system according to any one of the previous claims, wherein the discharging circuit is configured to provide a constant power output or a constant voltage or a constant current to the heating device, for example by discharging the temporary energy storage to a minimal non-zero operation voltage at which power delivery is still possible, for example wherein the minimal non-zero operation voltage is at least 5% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% of the nominal operating voltage of the temporary energy storage.

8. The aerosol-forming system according to any one of the previous claims, wherein the discharging circuit is configured to step-down an output voltage of the temporary energy storage to the heating device below a maximum voltage and / or the operating voltage of the temporary energy storage or to step-up the output voltage of the temporary energy storage to the heating device, for example while the voltage of the temporary energy storage drops during the provision of electric energy from the temporary energy storage to the heating device.

9. The aerosol-forming system according to any one of the previous claims, further including: a first bypass circuit between the temporary energy storage and the heating device, wherein the first bypass circuit is configured to bypass the discharging circuit and electrically connect the heating device to the temporary energy storage, and / or a second bypass circuit between the charging circuit and the heating device, wherein the second bypass circuit is configured to bypass the discharging circuit as well as the temporary energy storage and electrically connect the heating device to the charging circuit.

10. The aerosol-forming system according to the previous claim, wherein the charging circuit is configured to power the heating device by the second bypass circuit, for example in a maintenance phase, in which a temperature of the heating device is maintained.11 . The aerosol-forming system according to any one of the previous claims, wherein the heating device includes at least two heating elements, wherein the discharging circuit and / or the temporary energy storage is configured to power at least one heating element, and wherein the charging circuit is configured to simultaneously power at least one other heating element.

12. The aerosol-forming system according to any one of the previous claims, wherein the temporary energy storage includes at least two supercapacitors connected in parallel between the charging circuit and the discharging circuit, particularly wherein the charging circuit is configured to charge one of the at least two supercapacitors, while the discharging circuit is configured to simultaneously power the heating device by discharging another of the at least two supercapacitors.

13. The aerosol-forming system according to any one of the previous claims, including: an aerosol-forming device and a companion device configured to charge the aerosolforming device with electrical energy, wherein the temporary energy storage, the discharging circuit and optionally the heater device are arranged in the aerosol-forming device, and wherein the energy storage compartment or the energy storage compartment and the charging circuit are arranged in the companion device.

14. The aerosol-forming system according to any one of the previous claims, further including: an aerosol-forming article or substrate, wherein the aerosol-forming system is configured to form aerosol from the aerosol-forming article or substrate.

15. A method for powering a heating device in an aerosol-forming system, for example an aerosol-forming system according to any one of claims 1 to 14, including: stepping up or stepping down an input voltage provided by a removable energy source, for example a battery using a synchronous rectifier; charging a temporary energy storage, for example a supercapacitor, with the input voltage, the temporary energy storage not being a battery; stepping up or stepping down an output voltage of the temporary energy storage; and powering a heating device by the output voltage.

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