Method for monitoring an aerosol generation system and aerosol generation system

Abstract

A method for monitoring an aerosol product (1) is described. The aerosol generation system (1) includes a first energy storage device (14) configured to generate an aerosol by supplying power. The method includes charging the first energy storage device (14) with a direct current (DC) charging current. While the first energy storage device (14) is being charged, an alternating current (AC) signal is applied to the first energy storage device (14). The impedance of the first energy storage device (14) is estimated or determined using the voltage and current measurements obtained in response to the applied AC signal. The state of the first energy storage device (14) is estimated or determined using the impedance of the first energy storage device (14), for example, determining a failure or other state of the energy storage device (14) in response to a change in internal impedance.

Description

[Technical Field] 【0001】 This disclosure generally relates to a method for monitoring an aerosol generation system, and more particularly to an aerosol generation system which may include an aerosol product configured to be received by an aerosol generation device that generates aerosols to be inhaled by a user. The aerosol product may include an aerosol generation material or a substrate. 【0002】 This disclosure is particularly applicable to portable (portable) aerosol generators. [Background technology] 【0003】 In recent years, devices that generate inhalable aerosols by heating aerosol-generating materials without combustion have become popular with consumers. Commonly available risk reduction or risk modification devices are substrate-heating aerosol generators, or so-called non-combustion heating devices. These devices generate aerosols or vapors by heating aerosol-generating materials to temperatures typically in the range of 150°C to 300°C. This temperature range is typically extremely low compared to cigarettes. By heating the aerosol-generating materials to this temperature range without combustion, vapors are generated, which then typically cool and condense to form an aerosol for inhalation by the device user. [Overview of the project] [Problems that the invention aims to solve] 【0004】 Such devices can supply heat to aerosol-generating materials using one of many different methods. All methods of heating aerosol-generating materials typically require some kind of rechargeable power source or energy storage device, such as a battery (e.g., a lithium-ion secondary battery or battery pack). Energy storage devices are typically not replaceable or accessible to the user. This means that the need to perform complex monitoring of the energy storage device's condition is often avoided, as the aerosol-generating device manufacturer has complete control over the type and quality of the energy storage device. It also avoids the need to design the aerosol-generating device to support a wide range of different types of energy storage devices. However, a more serviceable design is also desirable, making the aerosol-generating device more sustainable and allowing the user to replace the energy storage device if necessary. If the energy storage device is replaceable, it may be necessary to verify whether the correct type of energy storage device is inserted or connected, and monitoring the condition of the energy storage device is usually required to ensure safe operation. Monitoring the condition of the energy storage device while charging will be particularly important, as this is often the most dangerous situation, especially with lithium-ion secondary batteries. Larger energy storage devices may include temperature sensors such as thermocouples or thermistors to monitor the temperature of the energy storage device. Since temperature sensors are typically located on the outer surface of the energy storage device housing, they can only monitor the surface temperature. When a malfunction occurs, the temperature of the energy storage device rises, and it is expected that the temperature sensor will detect this. The temperature rise may be the result of an internal malfunction, such as interface damage or an uncontrollable reaction in the electrodes, which could lead to a catastrophic failure such as thermal runaway. Depending on the location of the malfunction and the placement of the temperature sensor, detection may be significantly delayed. For example, if the temperature sensor is located at one end of the energy storage device and a malfunction occurs at the opposite end, it may take time for the temperature sensor to detect the localized temperature rise caused by the malfunction. Also, the temperature sensor may not always be in good thermal contact with the outer surface of the housing due to deterioration of the tape or adhesive used to fix the temperature sensor in place, for example.Accordingly, several embodiments of this disclosure provide an aerosol generation system that can monitor an energy storage device, particularly during charging, in an improved manner. Since the internal impedance is generally known to be related to the internal temperature of an energy storage device, the internal impedance of the energy storage device can be continuously monitored during charging. More specifically, the internal impedance is generally known to be inversely proportional to the internal temperature. More specifically, this inverse relationship between internal impedance and temperature generally applies to the expected operating temperature range of an energy storage device, where the ionic conductivity of the electrolyte is the main component of the internal impedance. Higher temperatures result in better ionic conductivity. (At high temperatures, resistance from other elements of the energy storage device, such as current collectors, tabs, terminals, etc., may increase to compensate for the better ionic conductivity of the electrolyte.) Internal failures in the energy storage device that lead to a rise in temperature also lead to a corresponding decrease in internal impedance. The proposed monitoring allows for a more accurate determination of the state of the energy storage device and ensures that the aerosol generator can be used safely even when the energy storage device is replaceable. [Means for solving the problem] 【0005】 According to a first aspect of this disclosure, a method is provided for monitoring an aerosol generation system including a first energy storage device configured to supply power and generate an aerosol, the method being: The first energy storage device is charged with a direct current (DC) charging current supplied by an external power source for the aerosol generation system or a second energy storage device, Applying an alternating current (AC) signal to the first energy storage device while it is being charged, To estimate or determine the internal impedance of the first energy storage device using voltage and current measurements obtained in response to an applied AC signal, This includes using the internal impedance of the first energy storage device to estimate or determine the state of the first energy storage device, for example, in response to changes in the internal impedance during charging, to estimate or determine a fault state, i.e., a state that indicates or may be related to the performance of the device. 【0006】 An aerosol generation system may include an aerosol generating device. An aerosol generating device is typically a portable, handheld device. 【0007】 The first energy storage device may be electrically connectable to an external power source, such as a Universal Serial Bus (USB) charger. The first energy storage device may be electrically connected to a charging circuit, which may be electrically connectable to an external power source. The first energy storage device may be charged from an external power source using the charging circuit. 【0008】 The first energy storage device may also be charged by a second energy storage device of the aerosol generation system. The first and second energy storage devices may, for example, be part of the aerosol generation device. The second energy storage device may also be charged by an external power source, optionally by a reversible buck-boost regulator electrically connected to the second energy storage device and charging circuit described above. 【0009】 The first energy storage device may have any suitable structure used in the aerosol generator and is configured to supply power for generating aerosols. The first energy storage device may be, for example, a lithium-ion secondary battery, a capacitor, or a capacitor module. An optional second energy storage device may also have any suitable structure used in the aerosol generator and is configured to supply power for generating aerosols. The second energy storage device may be, for example, a lithium-ion secondary battery, a capacitor, or a capacitor module. 【0010】 The first and second energy storage devices of the aerosol generation system may be the same or different. For example, one energy storage device may be a lithium-ion secondary battery, and the other may be a capacitor or a capacitor module. The capacitor may have any suitable structure, but in a preferred embodiment, it may be an electric double-layer supercapacitor. The capacitor may have a higher power density than conventional power sources such as batteries. As described above, the first and second energy storage devices may be charged by an external power source such as a USB charger. 【0011】 Each energy storage device may include an electrolyte, a pair of electrodes, and a porous separator between the electrodes. The pair of electrodes typically includes a positive electrode (or cathode) and a negative electrode (or anode). An AC signal may be applied between the positive and negative electrodes. The electrodes and separator are immersed in the electrolyte. Each energy storage device may include a positive terminal electrically connected to the positive electrode and a negative terminal electrically connected to the negative electrode. The positive and negative terminals allow each energy storage device to be connected to an external circuit. At least one of the first and second energy storage devices may be detachable or removable, and the positive and negative terminals may be able to electrically contact the corresponding fixed terminals of the external circuit of the aerosol generator, for example, if the external circuit of the aerosol generator is physically connected to the device. An aerosol generator including a removable energy storage device may be more sustainable, allowing the user to remove and replace a faulty or degraded energy storage device. 【0012】 In a capacitor, electric charge is stored in the electric field between the electrodes, and capacitance is a function of the surface area of ​​the electrodes, the distance between the electrodes, and the dielectric constant of the separator material. When a capacitor is charged by an external circuit connected to the pair of electrodes, cations in the electrolyte move toward the negative electrode and anions move toward the positive electrode, while electrons move from the negative electrode to the positive electrode via the external circuit. Thus, two charge layers with opposite polarities (electric double layers) are formed at the interface with the electrodes. When charging is complete, to stabilize the double layers on the electrodes, the positive charge on the positive electrode and the anions in the electrolyte attract each other, while the negative charge on the negative electrode and the cations in the electrolyte attract each other. A stable voltage is generated. The reverse process occurs when the capacitor discharges. 【0013】 In the case of a lithium-ion secondary battery, for example, during charging, the electrolyte transfers positively charged lithium ions from the positive electrode to the negative electrode via a separator, and electrons move from the negative electrode to the positive electrode via an external circuit. When a lithium-ion secondary battery is discharged, the lithium ions embedded in the negative electrode are released and return to the positive electrode, and electrons move from the positive electrode to the negative electrode via an external circuit. 【0014】 Each electrode may include at least one carbon-based electrode layer, for example, a layer of porous carbon material or activated carbon that has a large specific surface area per unit volume and is compatible with the proposed electrolyte. In the case of a lithium-ion secondary battery, the positive electrode may contain lithium metal oxide (e.g., lithium cobalt oxide (LiCoO2)) or other suitable material, and the negative electrode may contain graphite, for example. 【0015】 Each electrode may further include a current collector, which may contain a metal foil layer, such as an aluminum foil layer. Each current collector can facilitate the transfer of electrons through an external circuit. Carbon-based electrode layers may be arranged adjacent to one or both sides of the current collector. Each carbon-based electrode layer may be formed as a coating. Such electrodes can be manufactured relatively easily and inexpensively using materials already known to be used in aerosol products. Each current collector can facilitate the transfer of electrons through an external circuit. 【0016】 A separator is supposed to dielectrically separate pairs of oppositely charged electrodes. The separator also stores an electrolyte within its pores, allowing cations and anions to pass through during the charge-discharge process. The separator may contain any suitable material. 【0017】 The AC signal applied to the first energy storage device may be superimposed on a DC charging current from an external power source or the second energy storage device. 【0018】 If the aerosol generation system further includes a second energy storage device, the method may further include charging the first and second energy storage devices with a DC charging current supplied by an external power source (e.g., a USB charger). While the first and second energy storage devices are being charged, the method may further include superimposing an AC signal on the DC charging current supplied to the first energy storage device. 【0019】 Voltage measurements may be provided by a voltage sensing circuit, which may include, for example, a voltage divider circuit. Current measurements may be provided by a current sensing circuit, which may include a current sensing amplifier or other suitable current sensor. These voltage and current sensing circuits enable reliable and low-cost estimation or determination of the state of the first energy storage device (and, in some embodiments, an optionally selected second energy storage device). More specifically, an AC signal may be applied to the second energy storage device while it is charging. The AC signal is preferably applied sequentially to each energy storage device. In other words, the AC signal may be applied to the first energy storage device so that its state can be estimated or determined, and the AC signal may then be applied to the second energy storage device so that its state can be estimated or determined. The AC signals applied to each energy storage device may be the same or different. 【0020】 Voltage and current measurement values may be provided to a controller that estimates or determines the internal impedance of the first energy storage device. In a continuous process of monitoring the state of the first energy storage device, a series of internal impedance values are preferably estimated or determined during charging. For high-speed and repeatable measurements, the frequency of the AC signal may preferably be in the range of, for example, about 100 Hz to about 3 kHz, more preferably in the range of about 800 Hz to about 1.2 kHz. 【0021】 The root mean square (RMS) values V rms of voltage and current, I rms can be determined as follows. 【Equation】 Here, T is the time for taking the average of the instantaneous voltage and current. 【0022】 If the RMS value is known for a given frequency f of the AC signal (f = ω / 2π, where ω is the angular frequency), the magnitude of the internal impedance Z can be estimated or determined as follows. 【Equation】 【0023】 The state of the first energy storage device is estimated or determined using the internal impedance value. 【0024】 For example, when charging is started, one or more internal impedance values may be determined and used as an initial value. The initial value may be the average of two or more internal impedance values. 【0025】 The initial state of the first energy storage device can be estimated or determined by comparing the initial value with one or more thresholds. For example, it is known that the internal impedance increases with the number of charging cycles (i.e., as the energy storage device ages), and if the initial value exceeds the first threshold, it may indicate that the first energy storage device needs to be replaced. If it exceeds a second threshold, which is higher than the first threshold, it may indicate that the first energy storage device is not suitable for operation and charging should be stopped. The user may be notified as appropriate. 【0026】 The subsequent internal impedance value may be determined during the charging of the first energy storage device. Internal impedance is generally known to be inversely proportional to the temperature of the energy storage device within its expected operating temperature range. Therefore, as the temperature of the energy storage device rises, each of its internal impedances usually decreases, and vice versa. If the energy storage device is not faulty or degraded and is charging normally, such changes in temperature and internal impedance will be relatively small. However, in the case of a fault, for example, the changes will be more significant, i.e., a significant change will occur in the subsequent internal impedance value determined by the monitoring process. As will be described in more detail below, the internal impedance value may be used in addition to or as a substitute for the temperature measurement indicated by a temperature sensor (e.g., a thermocouple or thermistor) which may be integrated with the first energy storage device. The temperature sensor may, for example, indicate a measurement of the surface temperature of the first energy storage device. The validity of the temperature measurement indicated by the temperature sensor can be checked using the internal impedance value. 【0027】 The state of the first energy storage device during charging can be estimated or determined by comparing the subsequent internal impedance value with one or more thresholds. For example, if the subsequent value is lower than a threshold, it may indicate that the temperature of the energy storage device is too high and charging should be stopped. It will be understood that a significant drop in internal impedance is likely to indicate a fault that requires charging to be stopped as soon as possible. Such monitoring provides a faster and more reliable response compared to, for example, relying on a measured temperature of the first energy storage device. In particular, it has been shown that if an energy storage device fails during charging, the internal impedance may begin to drop before any significant rise in the measured temperature of the energy storage device occurs, and thus fall below a predetermined threshold. If a fault condition is detected, charging may be stopped and the user may be notified. It may be necessary to remove and replace the faulty energy storage device so that the aerosol generator can operate safely again. 【0028】 The threshold may be determined by arbitrarily referring to the initial value of the internal impedance. For example, the threshold may be set so that the internal resistance falls below the threshold when the internal resistance has decreased by approximately 20-40% of its initial value. This allows the internal impedance to change as the number of charging cycles increases, i.e., as the first energy storage device ages. 【0029】 In some types of energy storage devices, a malfunction may cause the internal impedance to drop and then rise. If the subsequent value of the internal impedance is higher than a threshold, it may indicate that the energy storage device is overheating and charging should be stopped. 【0030】 If an AC signal is applied to the second energy storage device while it is charging, the same continuous process can also be used to monitor the state of the second energy storage device. 【0031】 A second aspect of this disclosure provides a method for monitoring an aerosol generation system which includes an energy storage device (e.g., the lithium-ion secondary battery or capacitor or capacitor module described above) configured to supply power for generating an aerosol, and a temperature sensor configured to measure the temperature of the energy storage device, the method being provided. Charging an energy storage device with a DC charging current, Applying the AC signal to the energy storage device while the energy storage device is being charged, To estimate or determine the internal impedance of an energy storage device using measured voltage and current values ​​obtained in response to an applied AC signal, This includes using the internal impedance of the energy storage device to determine whether the temperature measurement indicated by the temperature sensor is valid or not. 【0032】 The temperature sensor may be, for example, a thermocouple or a thermistor, and may be located on the outer surface of the energy storage device's casing. The temperature sensor is configured to measure the temperature of the energy storage device, for example, its surface temperature. The internal impedance value may be estimated or determined as described above, and is considered to better indicate the internal temperature of the energy storage device, i.e., the temperature inside the device casing, which may differ from the surface temperature. The temperature measurement shown by the temperature sensor during charging can be compared with the internal impedance value estimated or determined during charging. This comparison can be used to determine whether the temperature measurement shown by the temperature sensor is valid or not. For example, if the temperature sensor detects a decrease in the subsequent internal impedance value despite no increase in each temperature measurement, the validity of the temperature measurement may be set to "invalid" and the user may be notified. 【0033】 According to a third aspect of this disclosure, an aerosol generating system is provided, and this aerosol generating system is A first energy storage device (for example, a lithium-ion secondary battery, a capacitor, or a capacitor module), An inverter electrically connected to the first energy storage device and configured to supply an AC signal, A superposition circuit electrically connected to an inverter and a first energy storage device, the superposition circuit configured to superimpose the AC signal supplied by the inverter onto a DC charging current supplied by an external power source (e.g., a USB charger) or a second energy storage device (e.g., a lithium-ion secondary battery or capacitor or capacitor module) of the aerosol generation system, It is a controller, A DC charging current and a superimposed AC signal are supplied to the first energy storage device to charge it. The internal impedance of the first energy storage device is estimated or determined using the measured voltage and current values ​​obtained in response to the AC signal. It includes a controller configured to estimate or determine the state of the first energy storage device using its internal impedance. 【0034】 The aerosol generation system may further include a charging circuit that can be electrically connected to an external power source. A switch, such as a semiconductor switch, may be electrically connected between the charging circuit and the first energy storage device. The input of the superimposed circuit may be electrically connected between the charging circuit and the switch, and the output of the superimposed circuit may be electrically connected between the switch and the first energy storage device. The controller may further be configured to open the switch if an AC signal is supplied to the first energy storage device. The controller may further be configured to close the switch if no AC signal is supplied to the first energy storage device and a DC charging current supplied by an external power source is supplied to the first energy storage device. 【0035】 The aerosol generation system may further include a second energy storage device (e.g., a lithium-ion secondary battery, capacitor, or capacitor module). The input of the superimposed circuit may be electrically connected to the second energy storage device. Alternatively, the output of the superimposed circuit may be electrically connected to the second energy storage device. 【0036】 The aerosol generation system may further include a first switching circuit electrically connected between the superimposed circuit and the second energy storage device. The first switching circuit may be electrically connectable to an external power supply. The first switching circuit may be configured to selectively connect the input of the superimposed circuit (e.g., the non-inverting input terminal of the operating amplifier of the superimposed circuit) to either the second energy storage device or the external power supply. The first switching circuit may also be electrically connected to the first energy storage device. The first switching circuit may be configured to selectively connect the input of the superimposed circuit to one of the first energy storage device, the second energy storage device, and the external power supply. The first switching circuit may be, for example, a single-pole triple-throw switching circuit. 【0037】 The aerosol generation system may further include a second switching circuit electrically connected between the inverter and the second energy storage device. The second switching circuit may be electrically connectable to an external power supply. The second switching circuit may be configured to selectively connect the input of the inverter (e.g., the input voltage terminal of the inverter) to either the second energy storage device or the external power supply. The second switching circuit may also be electrically connected to the first energy storage device. The second switching circuit may be configured to selectively connect the input of the inverter to one of the first energy storage device, the second energy storage device, and the external power supply. The second switching circuit may be, for example, a single-pole three-throw switching circuit. 【0038】 The aerosol generation system may further include a voltage sensing circuit configured to measure the voltage across the first energy storage device when an AC signal is supplied to the first energy storage device. The voltage sensing circuit may be electrically connected between the output of the superimposed circuit (e.g., the output terminal of the operating amplifier of the superimposed circuit) and the first energy storage device. 【0039】 The aerosol generation system may further include a current sensing circuit configured to measure the current flowing through the first energy storage device when an AC signal is supplied to the first energy storage device. The current sensing circuit may include a shunt resistor and a current sensing amplifier electrically connected to the shunt resistor. The aerosol generation system may further include a third switching circuit electrically connected to the first energy storage device and configured to connect the first energy storage device directly to earth or selectively to earth via the shunt resistor of the current sensing device. More specifically, when the first energy storage device is charging, the first energy storage device is connected to earth via the shunt resistor, and the AC signal is superimposed on the DC charging current supplied to the first energy storage device. 【0040】 If the aerosol generation system includes a second energy storage device to which an AC signal may also be applied during charging, the aerosol generation system may further include a third switching circuit electrically connected between the superposition circuit and the first and second energy storage devices. The third switching circuit may be configured to selectively connect the output of the superposition circuit to one of the first and second energy storage devices. The third switching circuit may include one input terminal and two output terminals, each output terminal being selectively electrically connected to the positive terminal of each energy storage device. The third switching circuit may be controlled by a controller, for example, in response to a selection signal to select an output terminal. A single superposition circuit can selectively output the superimposed AC signal to each energy storage device by the third switching circuit. This means that there is no need to provide a separate superposition circuit for each energy storage device, and the electrical circuit of the aerosol generation system can be kept as simple as possible. The third switching circuit may include a single-pole double-throw switching circuit. 【0041】 The aerosol generation system may further include a plurality of fourth switching circuits. Each fourth switching circuit may be electrically connected to each energy storage device and may be configured to selectively connect the negative terminal of each energy storage device directly to ground when the energy storage device is discharging, or to ground via a shunt resistor of the current sensing device when the energy storage device is charging and an AC signal is applied. Each fourth switching circuit may include one input terminal and two output terminals, one output terminal being electrically connected to the ground connection of the current sensing circuit, and the other output terminal being electrically connected to one end of the shunt resistor. The other end of the shunt resistor is electrically connected to ground. The input terminal of each fourth switching circuit may be electrically connected to the negative terminal of each energy storage device. Each of the fourth switching circuits may include a single-pole double-throw switching circuit. A single current sensing circuit may be selectively connected to each of the first and second energy storage devices by the fourth switching circuit. This means that multiple current sensing circuits are not required. Also, the number of terminals or pins of the controller used can be minimized. Each of the fourth switching circuits may be controlled by a controller, for example, in response to a selection signal that selects an output terminal. A common selection signal can be provided to the third switching circuit and each of the fourth switching circuits to enable coordinated switching control. 【0042】 The aerosol generation system may include an aerosol generator configured to generate heated vapor by heating the aerosol generating material or substrate without burning the aerosol generating material, thereby evaporating at least one component of the aerosol generating material, and then cooling and condensing the vapor to form an aerosol that the user of the aerosol generator inhales. The aerosol generator may generate the aerosol in another way, for example, by using an ultrasonic transducer to atomize a liquid aerosol-forming substrate. 【0043】 Generally, vapor is a substance that exists in the gaseous phase at temperatures below its critical temperature, meaning that vapor can be condensed into a liquid by increasing the pressure without lowering the temperature, whereas aerosol is a suspension of fine solid particles or droplets in air or other gases. However, it should be noted that the terms “aerosol” and “vapor” may be used interchangeably herein, particularly with respect to the form of inhalable medium produced for inhalation by the user. 【0044】 The aerosol generator may include a heating chamber that receives at least a portion of the aerosol generating material, and a heater configured to heat the aerosol generating material to generate an aerosol. The heater may be a low-power thin-film heater, a printing heater, etc. An induction heater may be preferred. The induction heater may include an induction coil and a susceptor, and may be configured to heat the aerosol generating material. For example, the induction coil may be located adjacent to the aerosol generation space or heating chamber of the aerosol generator designed to receive the aerosol generating material, and the aerosol generating material is optionally part of the aerosol product or consumables received by the aerosol generator during use. If an electrolyte is heated using an induction heater, an alternating current electromagnetic field is generated by the induction coil. The susceptor may be associated with the aerosol generating material, for example, located adjacent to or embedded in the aerosol generating material, and may be part of the aerosol product or the aerosol generator. The susceptor couples with an electromagnetic field and generates heat due to eddy currents and / or magnetic hysteresis, which is then transferred from the susceptor to the electrolyte. To generate the alternating current electromagnetic field necessary for induction heating, the apparatus may further include an inverter electrically connected to the induction coil. The same inverter may be used to generate an AC signal applied to the first energy storage device and to estimate or determine its state. In particular, the inverter may be selectively electrically connected to the first energy storage device and the induction coil of the induction heater, for example, by a suitable switching circuit. 【0045】 The aerosol-generating material may contain any type of solid or semi-solid material. Exemplary types of aerosol-generating solids include powders, granules, pellets, shredded, stranded, particles, gels, strips, loose leaves, cut fillers, porous materials, foamed materials, or sheets. The aerosol-generating material may also contain plant-derived materials, particularly tobacco. Advantageously, the aerosol-generating substrate may include, for example, reconstituted tobacco comprising tobacco and any one or more inorganic fillers such as cellulose fibers, tobacco stem fibers, and calcium carbonate (CaCO3). 【0046】 Therefore, aerosol generating devices may be referred to as "heating devices," "heated non-combustion tobacco devices," "tobacco product vaporization devices," etc., and are interpreted as devices suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol generating material, including liquid materials or substrates. 【0047】 As briefly mentioned above, the aerosol generating material may form part of the aerosol product received by the aerosol generating device, for example, by inserting the aerosol product into the aerosol generating space or heating chamber of the aerosol generating device. The aerosol product may include a filter compartment containing, for example, cellulose acetate fibers at its proximal end. The filter compartment may constitute an inlet filter and may be coaxially aligned with the aerosol generating material. One or more vapor collection areas, cooling areas, and other structures may also be included in some designs. For example, the aerosol product may include at least one tubular compartment upstream of the filter compartment. The tubular compartment can function as a vapor cooling area. The vapor cooling area advantageously allows the heated vapor generated by heating the aerosol generating material to cool and condense, forming an aerosol with properties suitable for inhalation by the user, for example, through the filter compartment. 【0048】 The aerosol-generating material may contain an aerosol-forming agent. Examples of aerosol-forming agents include polyhydric alcohols such as glycerin or propylene glycol, and mixtures thereof. Typically, the aerosol-forming agent content of the aerosol-generating material may be about 5% to about 50% on a dry weight basis. In some embodiments, the aerosol-forming agent content of the aerosol-generating material may be about 10% to about 20% on a dry weight basis, and possibly about 15% on a dry weight basis. 【0049】 When heated, the aerosol-generating material can release volatile compounds. These volatile compounds may include nicotine or flavoring compounds such as tobacco flavoring. 【0050】 The aerosol generating material may be a liquid material or substrate, and the apparatus may include an atomizing configuration that atomizes the liquid material or substrate, including non-heating. The liquid material or substrate may also be heated. [Brief explanation of the drawing] 【0051】 [Figure 1] This is a schematic diagram of an example of an aerosol generation system including an aerosol generator and aerosol products. [Figure 2] This is a schematic representation of an example of an electrical circuit in an aerosol generator. [Figure 3-10] This is a schematic representation of an example electrical circuit in Figure 2 illustrating different monitoring processes. [Modes for carrying out the invention] 【0052】 Hereinafter, several embodiments of this disclosure will be described as mere examples, with reference to the accompanying drawings. 【0053】 First, referring to Figure 1, an example of an aerosol generation system 1 including an aerosol generator 2 and an aerosol product 4 is shown in general terms. 【0054】 The aerosol product 4 is substantially cylindrical and may contain an aerosol generating material 6. At its proximal end, the aerosol product 4 includes a mouthpiece 8 with an outlet 10, allowing the user to inhale the aerosol generated by heating the aerosol generating material 6 through the outlet 10. 【0055】 The aerosol generating device 2 includes an electrical circuit 12, a first energy storage device 14 such as a battery (e.g., a lithium-ion secondary battery), and a second energy storage device 16 such as a capacitor or capacitor module (e.g., one or more electric double-layer capacitors). 【0056】 The aerosol generator 2 may optionally include one or more heaters or other aerosol generators. The aerosol generator 2 shown in Figure 1 includes an induction heater having an induction coil 18 positioned adjacent to the aerosol generation space or heating chamber 20 for heating the aerosol generating material 6 when the aerosol product 4 is inserted into the aerosol generator 2. The aerosol product 4 may include one or more susceptors (not shown) that generate heat due to eddy currents and / or magnetic hysteresis in conjunction with an electromagnetic field, and this heat is then transferred from the susceptors to the aerosol generating material 6. It will be easily understood that other aerosol generators may be used, including those configured to generate aerosols without heating by using an ultrasonic transducer to atomize a liquid aerosol-forming substrate. 【0057】 An example of electrical circuit 12 is shown in Figure 2. Electrical circuit 12 is, - Charging circuit 22, -DC / DC converter 24, -Inverter 26 and, - Low dropout (LDO) regulator 28, - Reversible step-up / step-down regulator 30, - Microcontroller unit (MCU) 32, - The first switching circuit 34, - The second switching circuit 36, - The third switching circuit 38, -The fourth switching circuit pair 40A, 40B, - Superimposed circuit 42, -Voltage detection circuit 44, -Current detection circuit 46, -Includes a temperature sensor 66 integrated with the first energy storage device 14. 【0058】 The charging circuit 22, DC / DC converter 24, inverter 26, LDO regulator 28, reversible boost regulator 30, MCU 32, first switching circuit 34, second switching circuit 36, third switching circuit 38, and fourth switching circuits 40A and 40B may be implemented as integrated circuits. 【0059】 The charging circuit 22 is - An input terminal (labeled "VBUS") that can be electrically connected to an external power supply (not shown), -The first semiconductor switch Q1 electrically connects the battery terminal (labeled "BAT") to the positive terminal of the first energy storage device 14, i.e., the lithium-ion secondary battery, - System terminals electrically connected to system bus 48 (labeled "SYS"), - A switching node terminal (labeled "SW") electrically connected to the system terminal by an inductor, - An earth terminal electrically connected to ground (labeled "GND"), - The serial data terminal (labeled "SDA") and serial clock terminal (labeled "SCL") are electrically connected to the corresponding terminals of the MCU32, -Includes a start terminal (labeled "EN") that is electrically connected to the first input / output terminal (labeled "I / O") of the MCU32, allowing the MCU32 to charge the first energy storage device 14 from an external power source (not shown). 【0060】 The first energy storage device 14 can be charged from an external power source (e.g., a universal serial bus (USB) charger, not shown) using the charging circuit 22, and the output voltage at the system terminal can be provided to the system bus 44. The output voltage at the system terminal of the charging circuit 22 may be provided by an external power source (not shown) and / or the first energy storage device 14 connected to the input terminal and battery terminal of the charging circuit 22, respectively. The charging circuit 22 allows the external power source (not shown) to charge the first energy storage device 14 and simultaneously provide an output voltage at the system terminal. For example, the first energy storage device 14 and the second energy storage device 16 can be charged simultaneously using an external power source (not shown), in the latter case, via the system bus 48 and the reversible step-up regulator 30, which will be described in more detail below. In Figure 2, the voltage of the first energy storage device 14 is "V ES1 It is labeled as "V" and the voltage of the second energy storage device 16 is "V ES2 It is labeled as "V". The voltage of the external power supply is "V BUS It is labeled as "". 【0061】 The first switching circuit 34 is a single-pole three-throw (SPTT) switch. -A first input terminal (labeled "Y0") is electrically connected between the first semiconductor switch Q1 and the battery terminal of the charging circuit 22, -The second input terminal (labeled "Y1") is electrically connected by the second semiconductor switch Q2 to the positive terminal and capacitor terminal (labeled "cap" of the reversible step-up / step-down regulator 30) of the second energy storage device 16, -A third input terminal (labeled "Y2") electrically connected to the system bus 48, - Output terminal (labeled "Z") - A pair of selection terminals (labeled "S0" and "S1") are electrically connected to the second and third input / output terminals (labeled "I / O") of the MCU32, respectively, and the MCU32 selectively controls which input terminal is connected to the output terminal by two selection signals, that is, it selects whether the output terminal Z is electrically connected to (i) the junction between the battery terminal of the charging circuit 22 and the first semiconductor switch Q1 via the first input terminal Y0, (ii) the junction between the capacitor terminal of the reversible boost regulator 30 and the second semiconductor switch Q2 via the second input terminal Y1, or (iii) the system bus 48 via the third input terminal Y2. -A power supply terminal (labeled "VDD") that is electrically connected to the voltage output terminal of the LDO regulator 28 and receives a constant voltage supply, - A start terminal (labeled "EN") is electrically connected to the fourth input / output terminal of the MCU32 (labeled "I / O"), which allows the MCU32 to start and stop the operation of the first switching circuit 34, - Includes an earth terminal (labeled "GND") electrically connected to the ground. 【0062】 The selection signals from the second and third input / output terminals of the MCU32 to the pair of selection terminals of the first switching circuit 34 (labeled "S0" and "S1") may be either low or high. In Figure 2, the selection signal from the second input / output terminal of the MCU32 to selection terminal S0 is labeled "SELECTS0_SPTT1", and the selection signal from the third input / output terminal of the MCU32 to selection terminal S1 is labeled "SELECTS1_SPTT1". The possible connections between input terminals Y0, Y1, and Y2 and output terminal Z are shown in Table 1 below. 【0063】 [Table 1] 【0064】 For example, if both selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 are low, it can be seen that the first input terminal Y0 is electrically connected to the output terminal Z. In this case, if the first semiconductor switch Q1 is switched on, the output terminal Z can receive DC current from either the battery terminal of the charging circuit 22 or the first energy storage device 14. If selection signal SELECTS0_SPTT1 is high and selection signal SELECTS1_SPTT1 is low, it can be seen that the second input terminal Y1 is electrically connected to the output terminal Z. In this case, if the second semiconductor switch Q2 is switched on, the output terminal Z can receive DC current from either the capacitor terminal of the reversible buck-boost regulator 30 or the second energy storage device 16. If selection signal SELECTS0_SPTT1 is low and selection signal SELECTS1_SPTT1 is high, it can be seen that the third input terminal Y2 is electrically connected to the output terminal Z. In this case, the output terminal Z can receive DC current from the system bus 48, i.e., the system terminal of the charging circuit 22. The first switching circuit 34 is therefore used to select a suitable power supply for the superimposed circuit 42, as will be described in more detail below. If both the selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 are high, it can be seen that the first input terminal Y0, the second input terminal Y1, and the third input terminal Y2 are simultaneously electrically connected to the output terminal Z. Such a connection is usually called broadcast mode. 【0065】 The DC / DC converter 24 typically operates as a boost (or step-up) converter, converting a DC input voltage into a suitable boosted DC output voltage. - A voltage input terminal (labeled "VIN") electrically connected to the output terminal of the first switching circuit 34, - A switching node terminal (labeled "SW") is electrically connected to the voltage input terminal by an inductor, -A voltage output terminal (labeled "VOUT") electrically connected to the induction heater 50 (or other suitable aerosol generator) by a third semiconductor switch Q3, - An earth terminal electrically connected to ground (labeled "GND"), - The serial data terminal (labeled "SDA") and serial clock terminal (labeled "SCL") are electrically connected to the corresponding terminals of the MCU32, - A feedback terminal (labeled "FB") that receives DC output voltage feedback, - It includes a start terminal (labeled "EN") which is electrically connected to the fifth input / output terminal of the MCU32 (labeled "I / O") and allows the MCU32 to start and stop the operation of the DC / DC converter 24. 【0066】 The voltage input and output terminals of the DC / DC converter 24 are electrically connected by a bypass circuit 52 that includes a fourth semiconductor switch Q4. 【0067】 The reversible buck-boost regulator 30 can operate in buck (or step-down) mode or boost (or step-up) mode. The system voltage ("V") of the system bus 48. SYS If the voltage (labeled as "low operating voltage") exceeds the minimum operating voltage, the reversible buck-boost regulator 30 typically operates in buck mode to charge the second energy storage device 16 from the system bus 48 until it is fully charged. Once the voltage on the system bus 48 is removed, the reversible buck-boost regulator 30 typically operates in boost mode to discharge the second energy storage device 16 to the system bus 48, thereby preventing the system voltage from dropping below the minimum operating voltage. The reversible buck-boost regulator 30 operates -The second semiconductor switch Q2 electrically connects the second energy storage device 16, i.e., the positive terminal of the capacitor module, and the second input terminal Y1 of the first switching circuit 34 to the capacitor terminal (labeled "CAP"), - A switching node terminal (labeled "LX") electrically connected to the second semiconductor switch Q2 by an inductor, - System terminals electrically connected to system bus 48 (labeled "SYS"), - An earth terminal electrically connected to ground (labeled "GND"), -A pair of feedback terminals (labeled "FB1" and "FB2") that receive DC input / output voltage feedback, - A current input terminal (labeled "ISET") for setting the peak discharge and discharge current of the reversible boost regulator 30, - It includes a start terminal (labeled "EN") which is electrically connected to the sixth input / output terminal of the MCU32 (labeled "I / O") and allows the MCU32 to start and stop the operation of the reversible buck-boost regulator 30. 【0068】 The second switching circuit 36 ​​is a single-pole three-throw (SPTT) switch. -A first input terminal (labeled "Y0") electrically connected to the output terminal of the first switching circuit 34, -A second input terminal (labeled "Y1") electrically connected to the positive terminal of the first energy storage device 14, -A third input terminal (labeled "Y2") electrically connected to the positive terminal of the second energy storage device 16, - Output terminal (labeled "Z") -Electrically connected to the 7th and 8th input / output terminals of the MCU32 (labeled "I / O"), respectively, a pair of selection terminals (labeled "S0" and "S1") that allow the MCU32 to selectively control which input terminal is connected to the output terminal using two selection signals, that is, to select whether the output terminal is electrically connected to (i) the output terminal Z of the first switching circuit 34 via the first input terminal Y0, (ii) the positive terminal of the first energy storage device 14 via the second input terminal Y1, or (iii) the positive terminal of the second energy storage device 16 via the second input terminal Y2, -A power supply terminal (labeled "VDD") that is electrically connected to the voltage output terminal of the LDO regulator 28 and receives a constant voltage supply, - An activation terminal (labeled "EN") is electrically connected to the ninth input / output terminal of the MCU32 (labeled "I / O"), which allows the MCU32 to start and stop the operation of the second switching circuit 36, - Includes an earth terminal (labeled "GND") electrically connected to the ground. 【0069】 The selection signals from the seventh and eighth input / output terminals of the MCU32 to the pair of selection terminals (labeled "S0" and "S1") of the second switching circuit 36 ​​may be low or high. In Figure 2, the selection signal from the seventh input / output terminal of the MCU32 to selection terminal S0 is labeled "SELECTS0_SPTT2", and the selection signal from the eighth input / output terminal of the MCU32 to selection terminal S1 is labeled "SELECTS1_SPTT2". The possible connections between input terminals Y0, Y1, and Y2 and output terminal Z are shown in Table 2 below. 【0070】 [Table 2] 【0071】 For example, if both selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are low, then the first input terminal Y0 is electrically connected to the output terminal Z. In this case, the output terminal Z can receive DC current from the output terminal of the first switching circuit 34. If selection signal SELECTS0_SPTT2 is high and selection signal SELECTS1_SPTT2 is low, then the second input terminal Y1 is electrically connected to the output terminal Z. In this case, the output terminal Z can receive DC current from the first energy storage device 14. If selection signal SELECTS0_SPTT2 is low and selection signal SELECTS1_SPTT2 is high, then the third input terminal Y2 is electrically connected to the output terminal Z. In this case, the output terminal Z can receive DC current from the second energy storage device 16. The second switching circuit 36 ​​is therefore used to select a suitable power supply for the inverter 26, as will be described in more detail below. Similar to the first switching circuit 34, if both the selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are high, it can be seen that the first input terminal Y0, the second input terminal Y1, and the third input terminal Y2 are simultaneously electrically connected to the output terminal Z. 【0072】 Inverter 26 is, - A positive input terminal (labeled "IN+") electrically connected to the output terminal of the second switching circuit 36, - Positive output terminal (labeled "OUT+") and negative output terminal (labeled "OUT-"), - The serial data terminal (labeled "SDA") and serial clock terminal (labeled "SCL") are electrically connected to the corresponding terminals of the MCU32, - It includes a start terminal (labeled "EN") which is electrically connected to the tenth input / output terminal of the MCU32 (labeled "I / O") and allows the MCU32 to start and stop the operation of the inverter 26. 【0073】 Once activated, the inverter 26 can provide an AC signal to the positive output terminal. The AC signal has a frequency determined by the MCU 32 and has an appropriate waveform. The MCU 32 can control the AC signal by serial data communication with the inverter 26. The waveform may be, for example, a sine wave or a square wave, and depending on the waveform used, band-pass filtering of voltage and current measurements may be preferable. In this embodiment, the frequency of the AC signal may be, for example, about 1 kHz. However, in other embodiments, the frequency may be in the range of, for example, about 100 Hz to about 3 kHz. Preferably, the amplitude of the AC signal should not produce an overvoltage higher than about 5 to 10 mV (for an internal impedance of 500 mΩ and a maximum peak current of 0.1 to 0.02 A). 【0074】 In addition to the positive input terminal, the inverter 26 may include a negative input terminal not shown in Figure 2. Alternatively, the negative output terminal may also be used as a negative input terminal. 【0075】 The LDO regulator 28 is - An input terminal electrically connected to system bus 48 (labeled "IN"), - An output terminal that supplies a constant voltage (labeled "OUT"), - An earth terminal electrically connected to ground (labeled "GND"), - Includes a power-on terminal (labeled "EN") electrically connected to system bus 48. 【0076】 In this embodiment, the start terminal of the LDO regulator 28 operates according to positive logic, and the input and start terminal of the LDO regulator are electrically connected in parallel to the power supply 48. This means that the LDO regulator 28 continuously outputs a constant voltage from its output terminal unless the system bus voltage is unavailable. The start terminals of the charging circuit 22, DC / DC converter 24, inverter 26, reversible buck-boost regulator 30, first switching circuit 34, and second switching circuit 36 ​​may use positive or negative logic. The constant output voltage of the LDO regulator 28 is "V MCU It is labeled as "". 【0077】 The MCU32 includes a power supply terminal (labeled "VDD") electrically connected to the output voltage terminal of the LDO regulator 28 and receiving a constant voltage supply. As described above, the MCU32 includes a serial data terminal (labeled "SDA") and a serial clock terminal (labeled "SCL") electrically connected to the corresponding terminals of the charging circuit 22, the DC / DC converter 24, and the inverter 26. The MCU32 also includes, - An earth terminal electrically connected to ground (labeled "GND"), - The first, fourth, fifth, sixth, ninth and tenth input / output terminals (labeled "I / O") are electrically connected to the charging circuit 22, the first switching circuit 34, the DC / DC converter 24, the reversible buck-boost regulator 30, the second switching circuit 36, and the start terminal of the inverter 26, respectively. - The second and third input / output terminals (labeled "I / O") are electrically connected to the pair of selection terminals S0 and S1 of the first switching circuit 34, respectively. -The seventh and eighth input / output terminals (labeled "I / O") are electrically connected to the pair of selection terminals S0 and S1 of the second switching circuit 36, respectively. - Includes 11th, 12th, 13th, and 14th input / output terminals (labeled "I / O") electrically connected to the first, second, third, and fourth semiconductor switches Q1, Q2, Q3, and Q4, respectively, to switch them on and off. 【0078】 When the first semiconductor switch Q1 is switched on, if the voltage of the external power supply is available, a DC current can be supplied from the battery terminal of the charging circuit 22 to the positive terminal of the first energy storage device 14. When the first semiconductor switch Q1 is switched off, the first input terminal Y0 of the first switching circuit 34 remains electrically connected to the battery terminal of the charging circuit 22 so that a DC current can be supplied to the first switching circuit 34 from the battery terminal. The first semiconductor switch Q1 may be a metal oxide semiconductor field-effect transistor (MOSFET) including a built-in body diode. The anode of the body diode is electrically connected to the positive terminal of the first energy storage device 14, and the cathode is electrically connected to the battery terminal of the charging circuit 22. This means that even if the first semiconductor switch Q1 is switched off, the first energy storage device 14 can continue to supply power to the battery terminal of the charging circuit 22. In the case of other types of semiconductor switches, for example, an antiparallel diode may be provided. 【0079】 When the second semiconductor switch Q2 is switched on, if the system bus voltage is available, a DC current can be supplied from the capacitor terminal of the reversible boost regulator 30 to the positive terminal of the second energy storage device 16. When the second semiconductor switch Q2 is switched off, the second input terminal Y1 of the first switching circuit 34 remains electrically connected to the capacitor terminal of the reversible boost regulator 30, so a DC current can be supplied from the capacitor terminal to the first switching circuit 34. The second semiconductor switch Q2 may be a MOSFET including a built-in body diode. The anode of the body diode is electrically connected to the positive terminal of the second energy storage device 16, and the cathode is electrically connected to the capacitor terminal of the reversible boost regulator 30. This means that even if the second semiconductor switch Q2 is switched off, the second energy storage device 16 can continue to supply power to the capacitor terminal of the reversible buck-boost regulator 30. In the case of other types of semiconductor switches, for example, an antiparallel diode may be provided. 【0080】 When the third semiconductor switch Q3 is switched on, the voltage output terminal of the DC / DC converter 24 is electrically connected to the induction heater 50 (or another suitable aerosol generator). When the third semiconductor switch Q3 is switched off, the induction heater 50 is electrically isolated from the voltage output terminal of the DC / DC converter 24 and the output of the bypass circuit 52. The induction heater 50 may be electrically isolated when heating is not required, for example, during the non-heating mode of the aerosol generator 2. The MCU 32 can control the operation of the inductor heater 50 by controlling the switching of the third semiconductor switch Q3 using any suitable control algorithm, for example, pulse width modulation (PWM) or pulse frequency modulation (PFM). 【0081】 When the fourth semiconductor switch Q4 is switched on, the voltage input and output terminals of the DC / DC converter 24 are electrically connected via the bypass circuit 52. This allows DC current to be supplied directly from the output terminal Z of the first switching circuit 34 to the superposition circuit 42, effectively bypassing the stopped DC / DC converter 24. If the DC / DC converter 24 can operate using a direct connection mode in which the DC / DC converter 24 outputs a voltage from its voltage output terminal that is substantially the same as the voltage supplied to the voltage input terminal, the fourth semiconductor switch Q4 and the bypass circuit 52 may be omitted. 【0082】 The positive voltage output terminal of the inverter 26 is electrically connected to the superposition circuit 42. The superposition circuit 42 is configured to superimpose the AC signal from the inverter 26 onto the DC current supplied by the DC / DC converter 24 or via the bypass circuit 52. The superposition circuit 42 includes an operation amplifier 54. The operation amplifier 54 is, -The first resistor R1 is electrically connected to the voltage output terminal of the DC / DC converter 24 and the output of the bypass circuit 52, and the first capacitor C1 and the second parallel resistor R2 are electrically connected to the ground connection of the superimposed circuit 42, and the non-inverting input terminal (labeled "+") is electrically connected to the ground connection of the superimposed circuit 42, - An inverting input terminal (labeled "-") electrically connected to the positive voltage output terminal of inverter 26, -The positive voltage terminal is electrically connected in parallel with the non-inverting input terminal of the operating amplifier 54 to the voltage output terminal of the DC / DC converter 28 and the output of the bypass circuit 52, -The negative voltage terminal electrically connected to the ground connection of the superimposed circuit 42, - Includes voltage output terminals. 【0083】 The junction 56 between the inverting input terminal of the operation amplifier 54 and the positive voltage output terminal of the inverter 26 is electrically connected to the output voltage terminal of the operation amplifier 54 by a third resistor R3 and to the ground connection by a fourth resistor R4. The negative output terminal of the inverter 26 is also electrically connected to the ground connection of the superimposed circuit 42. The output voltage at the voltage output terminal of the operation amplifier 54 has both an AC component and a DC component. 【0084】 The third switching circuit 38 is a single-pole double-throw (SPDT) switch. - An input terminal (labeled "Y") electrically connected to the voltage output terminal of the operating amplifier 54, -A first output terminal (labeled "Z1") electrically connected to the positive terminal of the first energy storage device 14, -A second output terminal (labeled "Z2") electrically connected to the positive terminal of the second energy storage device 16, - A selection terminal (labeled "SEL") is electrically connected to the 15th input / output terminal of the MCU32 (labeled "I / O"), allowing the MCU32 to selectively control which output terminal is connected to the input terminal by a selection signal, that is, allowing it to select whether the voltage output terminal of the operation amplifier 54 is electrically connected to the first energy storage device 14 by the first output terminal Z1, or to the second energy storage device 16 by the second output terminal Z2. -A power supply terminal (labeled "VDD") that is electrically connected to the output voltage terminal of the LDO regulator 28 and receives a constant voltage supply, - Includes an earth terminal (labeled "GND") electrically connected to the ground. 【0085】 The voltage detection circuit 44 is electrically connected to the junction 58 between the voltage output terminal of the operation amplifier 54 and the input terminal of the third switching circuit 38, and is configured to detect the voltage across one of the first and second energy storage devices 14 and 16 when an AC signal is applied. The 16th input / output terminal of the MCU 32 (labeled "I / O") is optionally electrically connected to the voltage detection circuit 44 by an AC coupling capacitor C2. An additional voltage detection circuit 60 receives an input voltage V from an external power supply (not shown). BUS It is configured to detect this. The 17th input / output terminal of the MCU32 (labeled "I / O") is electrically connected to an additional voltage sensing circuit 60. 【0086】 The current sensing circuit 46 includes a shunt resistor R5 and a current sensing amplifier 62 electrically connected to the shunt resistor. The shunt resistor R5 is electrically connected to the ground connection of the current sensing circuit 46. The 18th input / output terminal of the MCU 32 (labeled "I / O") is optionally electrically connected to the current sensing amplifier 62 of the current sensing circuit 46 by an AC-coupled capacitor C3. An additional operating amplifier 64 may be provided to improve the accuracy of current measurement by stabilizing the ground potential. 【0087】 Each of the fourth switching circuits 40A and 40B is a single-pole double-throw (SPDT) switch. One of the fourth switching circuits 40A is, - An input terminal (labeled "Y") electrically connected to the negative terminal of the first energy storage device 14, - The first output terminal (labeled "Z1") electrically connected to the shunt resistor R5 of the current sensing circuit 46, - The second output terminal (labeled "Z2") is electrically connected to the ground connection of the current sensing circuit 46, - A selection terminal (labeled "SEL") is electrically connected to the 15th input / output terminal of the MCU32 (labeled "I / O"), allowing the MCU to selectively control which output terminal is connected to the input terminal, that is, allowing the selection whether the negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 by the first output terminal Z1, or directly connected to the ground connection of the current sensing circuit 46 by the second output terminal Z2. -A power supply terminal (labeled "VDD") that is electrically connected to the output voltage terminal of the LDO regulator 28 and receives a constant voltage supply, - Includes an earth terminal (labeled "GND") electrically connected to the ground. 【0088】 The other fourth switching circuit 40B is, - An input terminal (labeled "Y") electrically connected to the negative terminal of the second energy storage device 16, - The first output terminal (labeled "Z1") is electrically connected to the ground connection of the current sensing circuit 46, - The second output terminal (labeled "Z2") electrically connected to the shunt resistor R5 of the current sensing circuit 46, - A selection terminal (labeled "SEL") is electrically connected to the 15th input / output terminal of the MCU32 (labeled "I / O"), allowing the MCU to selectively control which output terminal is connected to the input terminal, that is, allowing the selection whether the negative terminal of the second energy storage device 16 is electrically connected to the shunt resistor R5 by the second output terminal Z2, or directly connected to the ground connection of the current sensing circuit 46 by the first output terminal Z1. -A power supply terminal (labeled "VDD") that is electrically connected to the voltage output terminal of the LDO regulator 28 and receives a constant voltage supply, - Includes an earth terminal (labeled "GND") electrically connected to the ground. 【0089】 The selection signal (labeled "SELECT_AC_PATH") from the 15th input / output terminal of the MCU32 to the selection terminals of the third switching circuit 38 and the fourth switching circuit pair 40A and 50B may be either low or high. If the selection signal is low, the input terminal Y of each switching circuit 38, 40A, and 40B is connected to the first output terminal Z1, and if the selection signal is high, the input terminal Y of each switching circuit 38, 40A, and 40B is connected to the second output terminal Z2. In practice, this is because if the selection signal is low, -The voltage output terminal of the operating amplifier 54 of the superimposed circuit 42 is electrically connected to the positive terminal of the first energy storage device 14 via the third switching circuit 38. -The negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 of the current sensing circuit 46 via one of the corresponding switching circuits 40A. - This means that the negative terminal of the second energy storage device 16 is directly electrically connected to the ground connection of the current sensing circuit 46 via the corresponding fourth switching circuit 40B. This circuit configuration allows an AC signal to be applied to the first energy storage device 14 while it is charging, that is, the output voltage of the operating amplifier 54 of the superimposed circuit 42 having AC and DC components is provided to the positive terminal of the first energy storage device 14. 【0090】 If the selection signal is high, -The voltage output terminal of the operating amplifier 54 of the superimposed circuit 42 is electrically connected to the positive terminal of the second energy storage device 16 via the third switching circuit 38. - The negative terminal of the first energy storage device 14 is directly electrically connected to the ground connection of the current sensing circuit 46 via one of the corresponding fourth switching circuits 40A. - The negative terminal of the second energy storage device 16 is electrically connected to the shunt resistor R5 of the current sensing circuit 46 via the corresponding fourth switching circuit 40B. While this circuit device 16 is being charged, the output voltage of the operating amplifier 54 of the superimposed circuit 42, which has AC and DC components, is supplied to the positive terminal of the second energy storage device 16. 【0091】 A temperature sensor (e.g., a thermocouple or a thermistor) 66 is disposed on the outer surface of the first energy storage device 14 and configured to detect its surface temperature. The temperature sensor 66 is electrically connected to the 19th input / output terminal (labeled as "I / O") of the MCU 32. 【0092】 The signals labeled in FIG. 2 are summarized in Table 3 below. 【0093】 [Table 3] 【0094】 TIFF2026512536000007.tif130152 【0095】 The activation signals with the suffix "ENABLE_" may use positive logic, and the activation signals with the suffix "nENABLE_" may use negative logic. For example, the charging of the first energy storage device 14 from an external power source is activated if the activation signal nENABLE_CHARGING to the charging circuit 22 is low, and the operation of the buck-boost regulator 30 is activated if the activation signal ENABLE_REGULATOR is high. The activation signals ENABLE_ES1 and ENABLE_ES2 are activation signals for monitoring the states of the first and second energy storage devices 14 and 16, respectively. 【0096】 I 2 The I2C communication protocol may be used for serial data communication between the MCU 32 and the charging circuit 22, the DC / DC converter 24, and the inverter 26. Other suitable communication protocols such as SPI or UART may also be used. 【0097】 FIG. 3 shows a first method of monitoring the state of the first energy storage device 14 being charged by an external power source (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power source can be detected by an additional voltage detection circuit 60, i.e., using the signal DETECT_VBUS provided to the MCU 32. The signal DETECT_VBUS goes high if an external power source is connected. 【0098】 The first semiconductor switch Q1 is switched off by the MCU32 sending a high-level activation signal ENABLE_ES1 from the 11th input / output terminal. 【0099】 The charging circuit 22 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_CHARGING) from the first input / output terminal to the activation terminal of the charging circuit 22. 【0100】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a stop signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power terminal of the DC / DC converter 24. 【0101】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0102】 The reversible buck-boost regulator 30 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_REGULATOR) from the sixth input / output terminal to the start terminal of the reversible buck-boost regulator 30. 【0103】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since both selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 are low, the first input terminal Y0 is connected to the output terminal Z. 【0104】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Since both selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are low, the first input terminal Y0 is connected to the output terminal Z. 【0105】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high-level nENABLE_HEATER) from the 13th input / output terminal. 【0106】 The fourth semiconductor switch Q4 is switched on, bypassing the stopped DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0107】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is low, the input terminal Y is connected to the respective first output terminal Z1. 【0108】 A DC charging current is supplied from an external power source to the input terminal of the charging circuit 22. The DC current is supplied from the battery terminal of the charging circuit 22 to the first input terminal Y0 of the first switching circuit 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, the DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0109】 Simultaneously, a DC current is supplied from the output terminal Z of the first switching circuit 34 to the first input terminal Y0 of the second switching circuit 36, which is connected to the output terminal Z. A DC current is supplied from the output terminal Z of the second switching circuit 36 ​​to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, both the inverter 26 and the non-inverting input terminal of the operation amplifier 54 receive DC current from an external power supply. 【0110】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is low, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the first energy storage device 14 to charge the device. The negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. While the first energy storage device 14 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0111】 Figure 4 shows a second method for monitoring the state of the first energy storage device 14, which is being charged by an external power supply (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power supply can be detected by an additional voltage sensing circuit 60, i.e., by using the signal DETECT_VBUS provided to the MCU 32. If the external power supply is connected, the signal DETECT_VBUS becomes high. 【0112】 The first semiconductor switch Q1 is switched off when the MCU32 sends a high-level activation signal ENABLE_ES1 from the 11th input / output terminal. 【0113】 The charging circuit 22 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_CHARGING) from the first input / output terminal to the activation terminal of the charging circuit 22. 【0114】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power-up terminal of the DC / DC converter 24. 【0115】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0116】 The reversible buck-boost regulator 30 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_REGULATOR) from the sixth input / output terminal to the start terminal of the reversible buck-boost regulator 30. 【0117】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since both selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 are low, the first input terminal Y0 is connected to the output terminal Z. 【0118】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals of the second switching circuit 36 ​​to the selection terminals S0 and S1. Since the selection signal SELECTS0_SPTT2 is low and the selection signal SELECTS1_SPTT2 is high, the third input terminal Y2 is connected to the output terminal Z. 【0119】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0120】 The fourth semiconductor switch Q4 is switched on, bypassing the stopped DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0121】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is low, the input terminal Y is connected to the respective first output terminal Z1. 【0122】 A DC charging current is supplied from an external power source to the input terminal of the charging circuit 22. The DC current is supplied from the battery terminal of the charging circuit 22 to the first input terminal Y0 of the first switching circuit 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, the DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0123】 A DC current is supplied from the positive terminal of the second energy storage device 16 to the third output terminal Y2 of the second switching circuit 36, which is connected to the output terminal Z. From the output terminal Z of the second switching circuit 36, a DC current is supplied to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, the inverter 26 receives a DC current from the second energy storage device 16, and the non-inverting input terminal of the operation amplifier 54 receives a DC current from an external power supply. 【0124】 Compared to the first method shown in Figure 3, the DC current is supplied intensively from the external power source to the first energy storage device 14, thereby improving the charging speed of the first energy storage device 14. 【0125】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is low, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the first energy storage device 14 to charge the device. The negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. While the first energy storage device 14 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0126】 Figure 5 shows a third method for monitoring the state of the first energy storage device 14, which is being charged by the second energy storage device 16. 【0127】 The first semiconductor switch Q1 is switched off when the MCU32 sends a high-level activation signal ENABLE_ES1 from the 11th input / output terminal. 【0128】 The charging circuit 22 is stopped. More specifically, the MCU 32 sends a stop signal (i.e., a high-level nENABLE_CHARGING) from the first input / output terminal to the start terminal of the charging circuit 22. 【0129】 The DC / DC converter 24 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a high-level ENABLE_CONVERTER) from the fifth input / output terminal to the activation terminal of the DC / DC converter 24. 【0130】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0131】 The reversible buck-boost regulator 30 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_REGULATOR) from the sixth input / output terminal to the start terminal of the reversible buck-boost regulator 30. 【0132】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since the selection signal SELECTS0_SPTT1 is high and the selection signal SELECTS1_SPTT1 is low, the second input terminal Y1 is connected to the output terminal Z. 【0133】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Since the selection signal SELECTS0_SPTT2 is low and the selection signal SELECTS1_SPTT2 is high, the third input terminal Y2 is connected to the output terminal Z. 【0134】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the DC / DC converter 24. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0135】 The fourth semiconductor switch Q4 is switched off. More specifically, the MCU32 sends a stop signal (i.e., a high-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0136】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is low, the input terminal Y is connected to the respective first output terminal Z1. 【0137】 A DC charging current is supplied from the second energy storage device 16 to the second input terminal Y1 of the first switching circuit 34, which is connected to the output terminal Z. In particular, the DC current flows through the body diode of the second semiconductor switch Q2. From the output terminal Z of the first switching circuit 34, the DC current is supplied to the voltage input terminal of the DC / DC converter 24. The boosted DC current is supplied from the voltage output terminal of the DC / DC converter 24 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0138】 DC current is also supplied from the positive terminal of the second energy storage device 16 to the third output terminal Y2 of the second switching circuit 36, which is connected to the output terminal Z. DC current is supplied from the output terminal Z of the second switching circuit 36 ​​to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both AC and DC components. In this embodiment, both the inverter 26 and the non-inverting input terminal of the operation amplifier 54 receive DC current from the second energy storage device 16. This method makes it possible to monitor the state of the first energy storage device 14 even without an external power supply. 【0139】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is low, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the first energy storage device 14 to charge the device. The negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. While the first energy storage device 14 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0140】 Figure 6 shows a fourth method for monitoring the state of the second energy storage device 16, which is being charged by an external power supply (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power supply can be detected by an additional voltage sensing circuit 60, i.e., using the signal DETECT_VBUS provided to the MCU 32. If the external power supply is detected, the signal DETECT_VBUS becomes high. 【0141】 The second semiconductor switch Q2 is switched off when the MCU32 sends a high-level activation signal ENABLE_ES2 from the 12th input / output terminal. 【0142】 The charging circuit 22 is stopped. More specifically, the MCU 32 sends a stop signal (i.e., a high-level nENABLE_CHARGING) from the first input / output terminal to the start terminal of the charging circuit 22. 【0143】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power-up terminal of the DC / DC converter 24. 【0144】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0145】 The reversible buck-boost regulator 30 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a high-level ENABLE_REGULATOR) from the sixth input / output terminal to the activation terminal of the reversible buck-boost regulator 30. 【0146】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT2 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since the selection signal SELECTS0_SPTT1 is high and the selection signal SELECTS1_SPTT1 is low, the second input terminal Y1 is connected to the output terminal Z. 【0147】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Because the selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are low, the first input terminal Y0 is connected to the output terminal Z. 【0148】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0149】 The fourth semiconductor switch Q4 is switched on, bypassing the deactivated DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0150】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is high, the input terminal Y is connected to the respective second output terminals Z2. 【0151】 A DC charging current is supplied from an external power supply (not shown) to the input terminal of the charging circuit 22. The DC current is supplied from the system terminal of the charging circuit 22 to the system terminal of the reversible buck-boost regulator 30 via the system bus 48. The DC current is supplied from the capacitor terminal of the reversible boost regulator 30 to the second input terminal Y1 of the first switching circuit 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, the DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0152】 Simultaneously, a DC current is supplied from the output terminal Z of the first switching circuit 34 to the first input terminal Y0 of the second switching circuit 36, which is connected to the output terminal Z. From the output terminal Z of the second switching circuit 36, a DC current is supplied to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, both the inverter 26 and the non-inverting input terminal of the operation amplifier 54 receive DC current from an external power supply. 【0153】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is high, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the second energy storage device 16 to charge the device. The negative terminal of the second energy storage device 16 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. While the second energy storage device 16 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0154】 Figure 7 shows a fifth method for monitoring the state of the second energy storage device 16, which is being charged by an external power supply (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power supply can be detected by an additional voltage sensing circuit 60, i.e., by the signal DETECT_VBUS provided to the MCU 32. If the external power supply is connected, the signal DETECT_VBUS becomes high. 【0155】 The second semiconductor switch Q2 is switched off when the MCU32 sends a high-level activation signal ENABLE_ES2 from the 12th input / output terminal. 【0156】 The charging circuit 22 is stopped. More specifically, the MCU 32 sends a stop signal (i.e., a high-level nENABLE_CHARGING) from the first input / output terminal to the start terminal of the charging circuit 22. 【0157】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power-up terminal of the DC / DC converter 24. 【0158】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0159】 The reversible buck-boost regulator 30 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a high-level ENABLE_REGULATOR) from the sixth input / output terminal to the activation terminal of the reversible buck-boost regulator 30. 【0160】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since the selection signal SELECTS0_SPTT1 is high and the selection signal SELECTS1_SPTT1 is low, the second input terminal Y1 is connected to the output terminal Z. 【0161】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Since the selection signal SELECTS0_SPTT2 is high and the selection signal SELECTS1_SPTT2 is low, the second input terminal Y1 is connected to the output terminal Z. 【0162】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0163】 The fourth semiconductor switch Q4 is switched on, bypassing the deactivated DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0164】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is high, the input terminal Y is connected to the respective second output terminals Z2. 【0165】 A DC charging current is supplied from an external power supply (not shown) to the input terminal of the charging circuit 22. The DC current is supplied from the system terminal of the charging circuit 22 to the system terminal of the reversible buck-boost regulator 30 via the system bus 48. The DC current is supplied from the capacitor terminal of the reversible buck-boost regulator 30 to the second input terminal Y1 of the first switching circuit 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, the DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0166】 DC current is supplied from the positive terminal of the first energy storage device 14 to the second input terminal Y1 of the second switching circuit 36, which is connected to the output terminal Z. DC current is supplied from the output terminal Z of the second switching circuit 36 ​​to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, the inverter 26 receives DC current from the first energy storage device 14, and the non-inverting input terminal of the operation amplifier 54 receives DC current from an external power supply. 【0167】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is high, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the second energy storage device 16 to charge the device. The negative terminal of the second energy storage device 16 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. While the second energy storage device 16 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0168】 Figure 8 shows a sixth method for monitoring the state of the first energy storage device 14, which is being charged by an external power supply (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power supply can be detected by an additional voltage sensing circuit 60, i.e., using the signal DETECT_VBUS provided to the MCU 32. If the external power supply is connected, the signal DETECT_VBUS becomes high. The second energy storage device 16 is also being charged by the external power supply at the same time. 【0169】 The first semiconductor switch Q1 is switched off when the MCU32 sends a high-level activation signal ENABLE_ES1 from the 11th input / output terminal. 【0170】 The second semiconductor switch Q2 is switched on when the MCU32 sends a low-level stop signal ENABLE_ES2 from the 12th input / output terminal. 【0171】 The charging circuit 22 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_CHARGING) from the first input / output terminal to the activation terminal of the charging circuit 22. 【0172】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power-up terminal of the DC / DC converter 24. 【0173】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0174】 The reversible buck-boost regulator 30 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a high-level ENABLE_REGULATOR) from the sixth input / output terminal to the activation terminal of the reversible buck-boost regulator 30. 【0175】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Because the selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 are low, the first input terminal Y0 is connected to the output terminal Z. 【0176】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Because the selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are low, the first input terminal Y0 is connected to the output terminal Z. 【0177】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0178】 The fourth semiconductor switch Q4 is switched on, bypassing the deactivated DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0179】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is low, the input terminal Y is connected to the respective first output terminal Z1. 【0180】 A DC charging current is supplied from an external power source (not shown) to the input terminal of the charging circuit 22. The DC current is supplied from the system terminal of the charging circuit 22 to the system terminal of the reversible buck-boost regulator 30 via the system bus 48. The DC current is supplied from the capacitor terminal of the reversible boost regulator 30 to the positive terminal of the second energy storage device 16 via the switched-on second semiconductor switch Q2. The second energy storage device 16 is therefore charged by the external power source. 【0181】 DC current is also supplied from the battery terminals of the charging device 22 to the first input terminal Y0 of the first switching device 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0182】 Simultaneously, a DC current is supplied from the output terminal Z of the first switching circuit 34 to the first input terminal Y0 of the second switching circuit 36, which is connected to the output terminal Z. From the output terminal Z of the second switching circuit 36, a DC current is supplied to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, both the inverter 26 and the non-inverting input terminal of the operation amplifier 54 receive DC current from an external power supply. 【0183】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is low, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the first energy storage device 14 to charge it. The negative terminal of the first energy storage device 14 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. The negative terminal of the second energy storage device 16 is electrically connected directly to ground. While the first energy storage device 14 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0184】 Figure 9 shows a seventh method for monitoring the state of the second energy storage device 16, which is being charged by an external power supply (e.g., a USB charger) electrically connected to the input terminal of the charging circuit 22. The external power supply can be detected by an additional voltage sensing circuit 60, i.e., using the signal DETECT_VBUS provided to the MCU 32. If the external power supply is connected, the signal DETECT_VBUS becomes high. The first energy storage device 14 is also being charged by the external power supply at the same time. 【0185】 The first semiconductor switch Q1 is switched on when the MCU32 sends a low-level stop signal ENABLE_ES1 from the 11th input / output terminal. 【0186】 The second semiconductor switch Q2 is switched off when the MCU32 sends a high-level activation signal ENABLE_2 from the 12th input / output terminal. 【0187】 The charging circuit 22 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_CHARGING) from the first input / output terminal to the activation terminal of the charging circuit 22. 【0188】 The DC / DC converter 24 is shut down. More specifically, the MCU 32 sends a shut-down signal (i.e., a low-level ENABLE_CONVERTER) from the fifth input / output terminal to the power-up terminal of the DC / DC converter 24. 【0189】 The inverter 26 is started. More specifically, the MCU 32 sends a start signal (i.e., a high-level ENABLE_INVERTER) from the 10th input / output terminal to the start terminal of the inverter 26. 【0190】 The reversible buck-boost regulator 30 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a high-level ENABLE_REGULATOR) from the sixth input / output terminal to the activation terminal of the reversible buck-boost regulator 30. 【0191】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The MCU 32 also sends selection signals SELECTS0_SPTT1 and SELECTS1_SPTT1 from the second and third input / output terminals to the selection terminals S0 and S1 of the first switching circuit 34. Since the selection signal SELECTS0_SPTT1 is high and the selection signal SELECTS1_SPTT1 is low, the second input terminal Y1 is connected to the output terminal Z. 【0192】 The second switching circuit 36 ​​is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. The MCU 32 also sends selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 from the seventh and eighth input / output terminals to the selection terminals S0 and S1 of the second switching circuit 36. Because the selection signals SELECTS0_SPTT2 and SELECTS1_SPTT2 are low, the first input terminal Y0 is connected to the output terminal Z. 【0193】 The third semiconductor switch Q3 is switched off, electrically disconnecting the induction heater 50 from the output of the DC / DC converter 24 and the bypass circuit 52. More specifically, the MCU 32 sends a stop signal (i.e., a high level nENABLE_HEATER) from the 13th input / output terminal. 【0194】 The fourth semiconductor switch Q4 is switched on, bypassing the deactivated DC / DC converter 24, thereby electrically connecting the voltage input / output terminals via the bypass circuit 52. More specifically, the MCU 32 sends a start signal (i.e., a low-level nBYPASS_CONVERTER) from the 14th input / output terminal. 【0195】 The MCU32 transmits the selection signal SELECT_AC_PATH from the 15th input / output terminal to the selection terminals of the third switching circuit 38 and the fourth switching circuits 40A and 40B. Because the selection signal SELECT_AC_PATH is high, the input terminal Y is connected to the respective second output terminals Z2. 【0196】 A DC charging current is supplied from an external power source (not shown) to the input terminal of the charging circuit 22. The DC current is supplied from the battery terminal of the charging device 22 to the positive terminal of the first energy storage device 14 via the switched-on first semiconductor switch Q1. The first energy storage device 14 is therefore charged by the external power source. 【0197】 DC current is also supplied from the system terminal of the charging circuit 22 to the system terminal of the reversible buck-boost regulator 30 via the system bus 48. DC current is supplied from the capacitor terminal of the reversible boost regulator 30 to the second input terminal Y1 of the first switching circuit 34, which is connected to the output terminal Z. From the output terminal Z of the first switching circuit 34, DC current is supplied via the bypass circuit 52 to the non-inverting input terminal of the operation amplifier 54 of the superimposed circuit 42. 【0198】 Simultaneously, a DC current is supplied from the output terminal Z of the first switching circuit 34 to the first input terminal Y0 of the second switching circuit 36, which is connected to the output terminal Z. From the output terminal Z of the second switching circuit 36, a DC current is supplied to the inverter 26. The inverter 26 provides an AC signal to the superposition circuit 42, i.e., the inverting input terminal of the operation amplifier 54. The AC signal from the inverter 26 is superimposed on the DC current supplied to the non-inverting input terminal of the operation amplifier 54 via the bypass circuit 52, so that the output of the superposition circuit, i.e., the output voltage of the operation amplifier 54, has both an AC component and a DC component. In this embodiment, both the inverter 26 and the non-inverting input terminal of the operation amplifier 54 receive DC current from an external power supply. 【0199】 Because the selection signal SELECT_AC_PATH from the 15th input / output terminal of the MCU32 to the select terminals of the third switching circuit 38 and the fourth switching circuit pair 40A, 40B is high, the output voltage of the operating amplifier 54 is supplied to the positive terminal of the second energy storage device 16 to charge it. The negative terminal of the second energy storage device 16 is electrically connected to the shunt resistor R5 of the current sensing circuit 46. The negative terminal of the first energy storage device 14 is electrically connected directly to ground. While the second energy storage device 16 is being charged, voltage and current measurements are detected by the voltage and current sensing circuits 44 and 46 and provided to the MCU32, i.e., the 16th and 18th input / output terminals of the MCU32. 【0200】 To obtain the charging status of the first or second energy storage devices 14, 16, the MCU 32 determines a series of internal impedance values ​​using voltage and current measurements obtained from voltage and current sensing circuits 44, 46. For the purposes of the following explanation, we assume that the first energy storage device 14 is being charged, but it will be understood that if it is being charged by an external power source, for example as shown in Figures 6-9, the second energy storage device 16 can be monitored using the same process. 【0201】 First, the MCU32 uses instantaneous voltage and current measurements to determine the voltage V rms and current Irms The RMS value is determined as follows: 【number】 Here, T is the period over which the average instantaneous voltage and current are calculated. 【0202】 If an RMS value is obtained for a given frequency f of the AC signal (f = ω / 2π, where ω is the angular frequency), the MCU32 can estimate or determine the magnitude of the internal impedance Z of the first energy storage device 14 as follows. 【number】 【0203】 The average of the first few values ​​of the internal impedance (e.g., the first 3 to 5 values) is adopted as the initial (or reference) value. The state of the first energy storage device 14 can be estimated or determined by comparing the initial value with one or more thresholds. For example, if the initial value exceeds the first threshold, it may indicate that the first energy storage device 14 needs to be replaced, and if it exceeds a second threshold that is higher than the first threshold, it may indicate that the first energy storage device 14 is not suitable for operation and charging should be stopped. The user may be notified as appropriate. 【0204】 The subsequent internal impedance values ​​may be determined during the charging of the first energy storage device 14. These subsequent values ​​can also be compared with one or more thresholds to estimate or determine the state of the first energy storage device 14 during charging. For example, if the subsequent values ​​fall below a threshold, it may indicate that the internal temperature of the first energy storage device 14 is too high and charging should be stopped. For example, if the internal impedance falls below approximately 20-40% of the initial value, charging may be stopped. 【0205】 The MCU 32 also receives temperature measurements from a temperature sensor 66 located on the outer surface of the housing of the first energy storage device 14. The temperature measurements provided by the temperature sensor 66 during charging are compared with the internal impedance value determined by the MCU 32 during charging of the first energy storage device 14. The comparison can be used to determine whether the temperature measurement is valid or not. For example, if the internal impedance value decreases by a certain amount (e.g., about x ohms or about x%) without the temperature sensor 66 measuring each rise in surface temperature (e.g., about y degrees or about y%), the validity of the temperature measurement may be set to "invalid" and the user notified. Other comparisons between the impedance value and the temperature measurement may also be used. 【0206】 To charge the first energy storage device 14 from an external power source electrically connected to the input terminal of the charging circuit 22 without applying an AC signal, it is sufficient to start the charging circuit 22 and switch on the first semiconductor switch Q1. The DC charging current can then be supplied to the input terminal of the charging circuit 22 and from the battery terminal of the charging circuit 22 to the positive terminal of the first energy storage device 14. The negative terminal of the first energy storage device 14 can be directly electrically connected to the ground connection of the current detection circuit 46 by setting the selection signal SELECT_AC_PATH to high. To charge the second energy storage device 16 from an external power source electrically connected to the input terminal of the charging circuit 22 without applying an AC signal, it is sufficient to start the charging circuit 22 and the reversible boost regulator 30 and switch on the second semiconductor switch Q2. The DC charging current can therefore be supplied to the input terminal of the charging circuit 22, to the system terminal of the reversible step-up regulator 30 operating in step-down mode via the system bus 48 from the system terminal of the charging circuit 22, and to the positive terminal of the second energy storage device 16 from the capacitor terminal of the reversible step-up regulator 30. The negative terminal of the second energy storage device 16 can be directly electrically connected to the ground connection of the current sensing circuit 46 by setting the selection signal SELECT_AC_PATH to low. 【0207】 Figure 10 shows how the first and / or second energy storage devices 14 and 16 discharge to supply power to the induction heater 50. The third semiconductor switch Q3 is switched on to electrically connect the induction heater 50 to the voltage output terminal of the DC / DC converter 24 and start it up. More specifically, the MCU 32 sends a start signal (i.e., a high level ENABLE_CONVERTER) from the fifth input / output terminal to the start terminal of the DC / DC converter 24 and a start signal (i.e., a low level nENABLE_HEATER) from the thirteenth input / output terminal to the third semiconductor switch Q3. The fourth semiconductor switch Q4 is switched off. More specifically, the MCU 32 sends a stop signal (i.e., a high level nBYPASS_CONVERTER) from the fourteenth input / output terminal. 【0208】 The first switching circuit 34 is activated. More specifically, the MCU 32 sends an activation signal (i.e., a low-level nENABLE_SPTT1) from the fourth input / output terminal to the activation terminal of the first switching circuit 34. The second switching circuit 36 ​​is shut down. More specifically, the MCU 32 sends a shutdown signal (i.e., a high-level nENABLE_SPTT2) from the ninth input / output terminal to the activation terminal of the second switching circuit 36. 【0209】 When the first energy storage device 14 is discharged, the charging circuit 22 is activated and supplies a DC current to the third input terminal Y2 of the first switching circuit 34. In particular, the DC current flows from the first energy storage device 14 to the battery terminal of the charging circuit 22 via the body diode of the first semiconductor switch Q1. When the selection signal SELECTS0_SPTT1 is set to low and the selection signal SELECTS1_SPTT1 is set to high, the third input terminal Y2 of the first switching circuit 34 is connected to the output terminal Z. The DC current is then supplied from the output terminal Z to the voltage input terminal of the DC / DC converter 24. The DC / DC converter 24 supplies the boosted DC current to the induction heater 50. 【0210】 When the second energy storage device 16 is discharged, the reversible boost regulator 30 is activated and a DC current is supplied to the third input terminal Y2 of the first switching circuit 34. In particular, the DC current flows from the second energy storage device 16 through the body diode of the second semiconductor switch Q2 to the capacitor terminal of the reversible boost regulator 30. When both the first and second energy storage devices 14 and 16 are discharged simultaneously, the third input terminal Y2 of the first switching device 34 receives DC current from both the charging circuit 22 and the reversible boost regulator 30. The third input terminal Y2 is connected to the output terminal Z by setting the selection signal SELECTS0_SPTT1 to low and the selection signal SELECTS1_SPTT1 to high. The DC current is then supplied from the output terminal Z to the voltage input terminal of the DC / DC converter 24. The DC / DC converter 24 supplies the boosted DC current to the induction heater 50. 【0211】 While exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to these embodiments without departing from the scope of the attached claims. Therefore, the breadth and scope of the claims should not be limited to the exemplary embodiments described above. 【0212】 Unless otherwise specified herein, or unless clearly inconsistent with the context, any combination of all possible variations of the features described above is also included in this disclosure. 【0213】 Unless explicitly denied by the context, the words “including,” “contains,” and similar phrases throughout this specification and the claims should be interpreted as inclusive, meaning “including, but not limited to,” rather than exclusive or exhaustive.

Claims

[Claim 1] A method for monitoring an aerosol generation system (1) which includes a first energy storage device (14) configured to supply power and generate aerosols, The first energy storage device (14) is charged with a DC charging current supplied by the aerosol generation system (1) or the second energy storage device (16), While the first energy storage device (14) is being charged, an AC signal is applied to the first energy storage device (14), The impedance of the first energy storage device (14) is estimated or determined using the voltage and current measurements obtained in response to the applied AC signal, A method comprising estimating or determining the state of the first energy storage device (14) using the impedance of the first energy storage device (14). [Claim 2] The method according to claim 1, wherein the AC signal applied to the first energy storage device (14) is superimposed on the DC charging current. [Claim 3] The aerosol generation system further includes a second energy storage device (16), and the method is The first and second energy storage devices (14, 16) are charged with a DC charging current supplied by an external power source, The method according to claim 1 or 2, comprising superimposing the alternating current (AC) signal onto the direct current (DC) charging current supplied to the first energy storage device (14) while the first and second energy storage devices (14, 16) are being charged. [Claim 4] A method for monitoring an aerosol generation system (1) which includes an energy storage device (14) configured to supply power and generate an aerosol, and a temperature sensor (66) configured to measure the temperature of the energy storage device (14), The energy storage device (14) is charged with a DC charging current, While the energy storage device (14) is being charged, an AC signal is applied to the energy storage device (14), The impedance of the energy storage device (14) is estimated or determined using the measured voltage and current values ​​obtained in response to the applied AC signal. A method comprising determining whether or not the temperature measurement value indicated by the temperature sensor is valid using the impedance of the energy storage device (14). [Claim 5] Aerosol generation system (1), The first energy storage device (14) and An inverter (26) is electrically connected to the first energy storage device (14) and configured to supply an AC signal, A superposition circuit (42) electrically connected to the inverter (26) and the first energy storage device (14), wherein the superposition circuit (42) is configured to superimpose the AC signal supplied by the inverter (26) onto the DC charging current supplied by the external power supply of the aerosol generation system (1) or the second energy storage device (16), A DC charging current and a superimposed AC signal are supplied to the first energy storage device (14) to charge the first energy storage device (14). The impedance of the first energy storage device (14) is estimated or determined using the measured voltage and current values ​​obtained in response to the AC signal. An aerosol generation system (1) including a controller (32) configured to estimate or determine the state of the first energy storage device (14) using the impedance. [Claim 6] The aerosol generation system (1) according to claim 5, A charging circuit (22) that can be electrically connected to an external power supply, The system further includes a switch (Q1) electrically connected between the charging circuit (22) and the first energy storage device (14), The input of the superimposed circuit (42) is electrically connected between the charging circuit (22) and the switch (Q1), The output of the superimposed circuit (42) is electrically connected between the switch (Q1) and the first energy storage device (14). The aerosol generation system (1) is further configured such that the controller (32) opens the switch (Q1) when the AC signal is supplied to the first energy storage device (14). [Claim 7] The aerosol generation system (1) according to claim 6, wherein the controller (32) is further configured to close the switch (Q1) when the AC signal is not supplied to the first energy storage device (14) and the DC charging current supplied by the external power supply is supplied to the first energy storage device (14). [Claim 8] The aerosol generating system (1) according to any one of claims 5 to 7, further comprising a second energy storage device (16), wherein the input terminal of the superimposed circuit (42) is electrically connected to the second energy storage device (16). [Claim 9] The aerosol generating system (1) according to any one of claims 5 to 7, further comprising a second energy storage device (16), wherein the output terminal of the superimposed circuit (42) is electrically connected to the second energy storage device (16). [Claim 10] The aerosol generation system (1) according to claim 8, further comprising a first switching circuit (34) electrically connected between the superimposed circuit (42) and the second energy storage device (16), wherein the first switching circuit (34) is electrically connectable to an external power supply, and the first switching circuit (34) is configured to selectively connect the input terminal of the superimposed circuit (42) to either the second energy storage device (16) or the external power supply. [Claim 11] The aerosol generation system (1) according to claim 10, wherein the first switching circuit (34) is electrically connected to the first energy storage device (14), and the first switching circuit (34) is configured to selectively connect the input terminal of the superimposed circuit (42) to one of the first energy storage device (14), the second energy storage device (16), and the external power supply. [Claim 12] The aerosol generation system (1) according to claim 10, further comprising a second switching circuit (36) electrically connected between the inverter (26) and the second energy storage device (16), wherein the second switching circuit (36) is electrically connectable to the external power supply, and the second switching circuit (36) is configured to selectively connect the input terminal of the inverter (26) to either the second energy storage device (16) or the external power supply. [Claim 13] The aerosol generation system (1) according to claim 12, wherein the second switching circuit (36) is electrically connected to the first energy storage device (14), and the second switching circuit (36) is configured to selectively connect the input terminal of the inverter (26) to one of the first energy storage device (14), the second energy storage device (16), and the external power supply. [Claim 14] The aerosol generation system (1) according to claim 5, further comprising a voltage detection circuit (44) configured to measure the voltage across the first energy storage device (14) when the AC signal is supplied to the first energy storage device (14), wherein the voltage detection circuit (44) is electrically connected between the output terminal of the superimposed circuit (42) and the first energy storage device (14). [Claim 15] The aerosol generation system (1) according to claim 5, further comprising a current sensing circuit (46) configured to measure the current flowing through the first energy storage device (14) when the AC signal is supplied to the first energy storage device (14), wherein the current sensing circuit (46) comprises a shunt resistor (R5) and a current sensing amplifier (62) electrically connected to the shunt resistor (R5), and the aerosol generation system (1) further comprises a switching circuit (40A) electrically connected to the first energy storage device (14) and configured to selectively connect the first energy storage device (14) directly to earth or to earth via the shunt resistor (R5) of the current sensing circuit (46).

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