Patent Publication Number: US-2021161211-A1

Title: Flavor generation system, method, and program

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation application of International Application No. PCT/JP2018/030243, filed on Aug. 13, 2018. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a flavor generation system, a method of controlling the flavor generation system, and a program. 
     BACKGROUND ART 
     In place of cigarettes, aerosol generation devices are known which generate aerosol for tasting by atomizing an aerosol source with an electric load such as a heater (PTL 1). The aerosol generation device includes a heating element that atomizes an aerosol source, a power source that supplies electric power to the heating element, and a controller that controls the load and the power source. 
     PTL 1 also discloses a method of charging a power source provided in the aerosol generation device or discharging the electric power from the power source. The method disclosed in PTL 1 includes a step of determining a rate of a charging current or a discharging current in dependence on an ambient temperature, and a step of charging the power source or discharging the electric power from the power source at the determined rate. 
     PTL 2 discloses a charging system for charging a secondary battery. The charging system disclosed in PTL 2 includes a temperature detection unit that detects a temperature of the secondary battery. When the temperature of the secondary battery detected by the temperature detection unit is within a range of preferred temperature preset as a temperature suitable for charge of the secondary battery, the charging current to be supplied from a charging unit to the second battery is adjusted so that the temperature of the secondary battery does not exceed an upper temperature of the preferred temperature range. 
     PTL 3 discloses a charger for charging a battery in a battery pack. In a charging method disclosed in PTL 3, it is determined whether a charging current is output, based on a detected value of a temperature of the battery and a detected value of a temperature of the charger. 
     CITATION LIST 
     Patent Literature 
     PTL 1: National Publication of International Patent Application No. 2017-518733 
     PTL 2: Japanese Patent Laid-Open No. 2009-183105 
     PTL 3: Japanese Patent Laid-Open No. 2017-005830 
     SUMMARY OF INVENTION 
     A first feature is a favor generation system including: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and a charging unit that includes a second controller and that is capable of charging the power source. The first controller and the second controller are configured to be capable of controlling a charging speed of the power source. In the control of the charging speed, a first object to be operated by the first controller is different from a second object to be operated by the second controller. 
     A second feature is the flavor generation system according to the first feature, including a sensor capable of outputting a detected value or an estimated value of a state of the power source. The first controller is configured to control the charging speed based on an output value of the sensor. 
     The sensor capable of outputting the detected value or the estimated value of the state of the power source may be, for example, a temperature sensor that measures or estimates a temperature of the power source or a sensor that measures or estimates an internal resistance of the power source. 
     A third feature is the flavor generation system according to the first or second feature, wherein the charging speed includes “0.” 
     A fourth feature is the flavor generation system according to any one of the first to third features, wherein the power source unit includes a first connection portion capable of being electrically connected to the charging unit, and a switch between the power source and the first connection portion, and the first controller is configured to control the charging speed to be set to “0” or not by operating the switch. 
     A fifth feature is the flavor generation system according to the fourth feature, wherein the power source unit includes a first temperature sensor that outputs a detected value or an estimated value of a temperature of the power source, and the first controller is configured to control the charging speed to be set to “0” or not by operating the switch, based on an output value of the first temperature sensor. 
     A sixth feature is the flavor generation system according to the fifth feature, wherein the power source includes an electrolytic solution or an ionic liquid. The first controller is configured to open the switch in a case where the output value of the first temperature sensor is equal to or lower than a predetermined temperature, which causes solidification of the electrolytic solution or the ionic liquid, or in a case where the temperature of the power source is estimated to be equal to or lower than the predetermined temperature based on the output value of the first temperature sensor. 
     A seventh feature is the flavor generation system according to the fifth feature, wherein the power source is a lithium-ion secondary battery, and the first controller is configured to open the switch in a case where the output value of the first temperature sensor is equal to or lower than a predetermined temperature at which electrodeposition occurs on an electrode in the power source, or in a case where the temperature of the power source is estimated to be equal to or lower than the predetermined temperature based on the output value of the first temperature sensor. 
     An eighth feature is the flavor generation system according to the fifth feature, wherein the first controller is configured to open the switch in a case where the output value of the first temperature sensor is equal to or higher than a predetermined temperature at which a change in structure or composition of an electrode occurs in the power source, or in a case where the temperature of the power source is estimated to be equal to or higher than the predetermined temperature based on the output value of the first temperature sensor. 
     A ninth feature is the flavor generation system according to any one of the first to eighth features, wherein the charging unit includes a conversion unit that is capable of converting a voltage or a current of input electric power and outputting the converted voltage or current, and the second controller is configured to be capable of adjusting a value of the voltage or the current to be output from the conversion unit by operating the conversion unit. 
     A tenth feature is the flavor generation system according to the ninth feature, wherein the charging unit includes a second temperature sensor, and the second controller is configured to be capable of adjusting the value of the voltage or the current to be output from the conversion unit by operating the conversion unit, based on an output value of the second temperature sensor. 
     An eleventh feature is the flavor generation system according to the tenth feature, wherein the second controller is capable of acquiring a value related to a remaining amount of the power source, and the second controller is configured to be capable of adjusting the value of the voltage or the current to be output from the conversion unit by operating the conversion unit, based on the value related to the remaining amount of the power source and the output value of the second temperature sensor. 
     A twelfth feature is the flavor generation system according to the tenth or eleventh feature, wherein the conversion unit is configured to be capable of performing a first charging mode, and a second charging mode in which a value of electric power or a current per unit time that can be output by the conversion unit is greater than that in the first charging mode, and the second controller is configured to cause the conversion unit to perform the second charging mode in a case where the output value of the second temperature sensor is equal to or higher than a threshold, and cause the conversion unit to perform the first charging mode in a case where the output value of the second temperature sensor is lower than the threshold. 
     A thirteenth feature is the flavor generation system according to any one of the tenth to twelfth features, wherein the second controller is configured to perform constant current charging and constant voltage charging in a case where the output value of the temperature sensor is equal to or higher than a threshold, and perform only the constant current charging out of the constant current charging and the constant voltage charging in a case where the output value of the temperature sensor is lower than the threshold. 
     A fourteenth feature is the flavor generation system according to any one of the tenth to twelfth features, wherein the second controller is configured so that a switching value which is a value related to the remaining amount of the power source when the constant current charging is switched to the constant voltage charging in a case where the output value of the temperature sensor is lower than a threshold is smaller than the switching value in a case where the output value of the temperature sensor is equal to or higher than the threshold. 
     A fifteenth feature is the flavor generation system according to the first feature, wherein the power source unit includes a first sensor, the charging unit includes a second sensor, the first sensor and the second sensor are configured to output values related to the same physical quantity, respectively, the first controller is configured to control the charging speed based on an output value of the first sensor, and the second controller is configured to control the charging speed based on an output value of the second sensor. 
     A sixteenth feature is the flavor generation system according to the first feature, wherein the power source unit includes a first sensor, the charging unit includes a second sensor, the first sensor and the second sensor are configured to output values related to physical quantities different from each other, respectively, the first controller is configured to control the charging speed based on an output value of the first sensor, and the second controller is configured to control the charging speed based on an output value of the second sensor. 
     A seventeenth feature is the flavor generation system according to the first feature, wherein the power source unit includes a first connection portion capable of being electrically connected to the charging unit, and a switch between the power source and the first connection portion, the charging unit includes a conversion unit that is capable of converting a current or a voltage of input electric power and outputting the converted current or voltage, the second controller is configured to be capable of performing a second control to adjust a value of the voltage or the current to be output from the conversion unit by operating the conversion unit, the first controller is configured to perform a first control to control the charging speed to be set to “0” or not by operating the switch, and the charging speed is controlled by the first control and the second control. 
     An eighteenth feature is the flavor generation system according to the seventeenth feature, wherein the power source unit includes a first temperature sensor that outputs a detected value or an estimated value of a temperature of the power source, the charging unit includes a second temperature sensor, the first controller is configured to perform the first control based on an output value of the first temperature sensor, and the second controller is configured to perform the second control based on an output value of the second temperature sensor. 
     A nineteenth feature is the flavor generation system according to the first feature, wherein the first controller is configured to control an amount of current or electric power to be reduced or not, the current or electric power to be input to the power source from the charging unit. 
     A twentieth feature is the flavor generation system according to any one of the first to nineteenth features, wherein the first controller and the second controller is configured to control a charge of the power source without communicating with each other. 
     A twenty-first feature is the flavor generation system according to any one of the first to twentieth features, wherein the power source unit and the charging unit are electrically connected to each other only by a main positive bus and a main negative bus. 
     A twenty-second feature is a method of charging a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, the method including the steps of: controlling a charging speed of the power source by operating a first object provided in a power source unit including the power source; and controlling the charging speed by operating a second object different from the first object, the second object being provided in the charging unit. 
     A twenty-third feature is a flavor generation system including: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and an external unit that includes a second controller and that receives electric power output from the power source. The first controller and the second controller are configured to be capable of controlling a discharging speed from the power source. In the control of the discharging speed, an object to be operated by the first controller is different from an object to be operated by the second controller. 
     Here, the external unit may be, for example, an atomization unit or flavor unit that includes an aerosol source or a flavor source, or may be another unit. 
     A twenty-fourth feature is a method of discharging electric power to an external unit from a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, the method including the steps of: controlling a discharging speed of the power source by operating a first object provided in a power source unit including the power source; and controlling the discharging speed by operating a second object different from the first object, the second object being provided in the external unit. 
     Here, the external unit may be, for example, an atomization unit or flavor unit that includes an aerosol source or a flavor source, or may be another unit. 
     A twenty-fifth feature is a flavor generation system including: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and an external unit that includes a second controller. The first controller and the second controller are configured to control a charge of the power source by the external unit or a discharge of electric power from the power source to the external unit. Out of determinations to be made in the charge or the discharge, the number of first options for the determination to be made by the first controller is smaller than the number of second options for the determinations to be made by the second controller. 
     Here, the external unit may be, for example, an atomization unit or flavor unit that includes an aerosol source or a flavor source, may be a charging unit capable of charging the power source, or may be another unit. 
     A twenty-sixth feature is a method of charging, by an external unit, a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source or discharging electric power from the power source to the external unit, the method including the steps of: selecting one among first options by a first controller provided in a power source unit including the power source; and selecting one among second options by a second controller provided in the external unit. The number of the first options is smaller than the number of the second options. 
     Here, the external unit may be, for example, an atomization unit or flavor unit that includes an aerosol source or a flavor source, may be a charging unit capable of charging the power source, or may be another unit. 
     A twenty-seventh feature is a flavor generation system including: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, a first controller, and a first temperature sensor that outputs a detected value or an estimated value of a temperature of the power source; and a charging unit that includes a second controller and the second temperature sensor, and that is capable of charging the power source. The first controller is configured to provide a first correlation for setting a charging condition of the power source based on an output value of the first temperature sensor. The second controller is configured to provide a second correlation for setting a charging condition of the power source, the second correlation being different from the first correlation, based on an output value of the second temperature sensor. The first controller and the second controller are configured to control a charge of the power source based on the first correlation and the second correlation. 
     A twenty-eighth feature is the flavor generation system according to the twenty-seventh feature, wherein the first controller and the second controller are configured to control a charge of the power source by preferentially using the first correlation out of the first correlation and the second correlation. 
     A twenty-ninth feature is a method of charging a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, the method including the steps of: acquiring an output value from a first temperature sensor provided in a power source unit including the power source; acquiring an output value from a second temperature sensor provided in a charging unit; and controlling a charge of the power source using a first correlation for setting a charging condition of the power source based on the output value of the first temperature sensor, and a second correlation for setting a charging condition of the power source based on the output value of the second temperature sensor. 
     A thirtieth feature is a program for causing a flavor generation system to execute the method according to the twenty-second, twenty-fourth, twenty-sixth or twenty-ninth feature. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded view illustrating a flavor generation device according to one embodiment. 
         FIG. 2  is a diagram illustrating an atomization unit according to one embodiment. 
         FIG. 3  is an enlarged perspective view of a part of a power source unit. 
         FIG. 4  is an exploded perspective view in which the part of the power source unit is disassembled. 
         FIG. 5  is a block diagram of the flavor generation device. 
         FIG. 6  is a diagram illustrating an electric circuit of the power source unit. 
         FIG. 7  is a diagram illustrating an electric circuit of the atomization unit and the power source unit in a state where a load is connected. 
         FIG. 8  is a diagram illustrating an electric circuit of a flavor generation system including the power source unit and a charging unit 
         FIG. 9  is a block diagram of the charging unit. 
         FIG. 10  is a map illustrating an example of a correlation (first correlation) between a temperature and a charging speed of a power source. 
         FIG. 11  is a map illustrating an example of a correlation (second correlation) between a temperature and a charging speed of the charging unit. 
         FIG. 12  is a map illustrating another example of the correlation (second correlation) between a temperature and a charging speed of the charging unit. 
         FIG. 13  is a flowchart illustrating an example of a control flow by a second controller of the charging unit. 
         FIG. 14  is a flowchart illustrating an example of a control flow by a first controller of the power source unit. 
         FIG. 15  is a flowchart illustrating another example of a control flow by the second controller of the charging unit. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments will be described. Note that the same or similar parts are denoted by the same or similar reference signs in the description of the drawings below. However, it should be noted that the drawings are schematic and each ratio in dimension may be different from an actual ratio. 
     Therefore, specific dimensions and the like should be determined with reference to the following description. Needless to say, the drawings may include parts which are different, in terms of the relation or ratio in dimension, from each other. 
     [Overview of Disclosure] 
     According to one aspect, a flavor generation system includes: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and a charging unit that includes a second controller and that is capable of charging the power source. The first controller and the second controller are configured to be capable of controlling a charging speed of the power source. In the control of the charging speed, a first object to be operated by the first controller is different from a second object to be operated by the second controller. 
     According to this aspect, the first controller of the power source unit and the second controller of the charging unit share the control of the charging speed of the power source. In particular, the first controller of the power source unit provided with the power source can be in charge of a part of the control of the charging speed. Therefore, more sophisticated and highly accurate control of the charging speed is made possible according to a state (environment) of the power source, for example. In particular, more sophisticated and highly accurate control of the charging speed is made possible without communication between the first controller of the power source unit and the second controller of the charging unit. 
     According to another aspect, a flavor generation system includes: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and an external unit that includes a second controller and that receives electric power output from the power source. The first controller and the second controller are configured to be capable of controlling a discharging speed from the power source. In the control of the discharging speed, an object to be operated by the first controller is different from an object to be operated by the second controller. 
     According to this aspect, the first controller of the power source unit and the second controller of the external unit share the control of the discharging speed of the power source. In particular, the second controller of the external unit can be in charge of a part of the control of the discharging speed. Therefore, more sophisticated and highly accurate control of the discharging speed is made possible according to a state (environment) of the external unit, for example. In particular, more sophisticated and highly accurate control of the discharging speed is made possible without communication between the first controller of the power source unit and the second controller of the external unit. 
     According to still another aspect, a flavor generation system includes: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, and a first controller; and an external unit that includes a second controller. The first controller and the second controller are configured to control a charge of the power source by the external unit or a discharge of electric power from the power source to the external unit. Out of determinations to be made in the charge or the discharge, the number of first options for the determination to be made by the first controller is smaller than the number of second options for the determinations to be made by the second controller. 
     According to this aspect, the following advantages are provided in addition to the above-described advantages. Since the number of first options for determination to be made by the first controller of the power source unit is smaller than the number of second options for determination to be made by the external unit, the first controller of the power source unit has a simpler configuration than that of the second controller of the external unit. In this way, the sizes and weights of the first controller and the power source unit including the first controller can be reduced, which is, particularly, more suitable for a portable flavor generation system. 
     According to yet another aspect, a flavor generation system includes: a power source unit that includes a power source that is electrically connected to or connectable to a load for atomizing an aerosol source or heating a flavor source, a first controller, and a first temperature sensor that outputs a detected value or an estimated value of a temperature of the power source; and a charging unit that includes a second controller and the second temperature sensor, and that is capable of charging the power source. The first controller is configured to provide a first correlation for setting a charging condition of the power source based on an output value of the first temperature sensor. The second controller is configured to provide a second correlation for setting a charging condition of the power source, the second correlation being different from the first correlation, based on an output value of the second temperature sensor. The first controller and the second controller are configured to control a charge of the power source based on the first correlation and the second correlation. 
     According to this aspect, the first controller of the power source unit and the second controller of the charging unit share the charge control of the power source. In particular, since the first controller and the second controller control the charge of the power source based on the correlations (first correlation and second correlation) different from each other, the first controller and the second controller can perform more complex control according to various states (environment) of the power source, for example. In particular, sophisticated control of the charge is made possible without communication between the first controller of the power source unit and the second controller of the charging unit. 
     EMBODIMENTS 
     Hereinafter, a flavor generation device according to one embodiment will be described.  FIG. 1  is an exploded view illustrating a flavor generation device according to one embodiment.  FIG. 2  is a diagram illustrating an atomization unit according to one embodiment.  FIG. 3  is an enlarged perspective view of a part of a power source unit.  FIG. 4  is an exploded perspective view in which the part of the power source unit is disassembled.  FIG. 5  is a block diagram of the flavor generation device.  FIG. 6  is a diagram illustrating an electric circuit of the power source unit.  FIG. 7  is a diagram illustrating an electric circuit of the atomization unit and the power source unit in a state where a load is connected to the power source. 
     A flavor generation device  100  may be a non-combustion-type flavor inhaler for sucking a flavor without combustion. The flavor generation device  100  may have a shape extending along a predetermined direction A that is a direction toward a suction port end E 1  from a non-suction port end E 2 . In this case, the flavor generation device  100  may include one end E 1  having a suction port  141  through which a user sucks a flavor and the other end E 2  on a side opposite to the suction port  141 . 
     The flavor generation device  100  may include a power source unit  110  and an atomization unit  120 . The atomization unit  120  may include a case  123 , and a load  121 R disposed inside the case  123 . The case  123  may form a part of the outermost outer surface of the flavor generation device. 
     The atomization unit  120  may be configured to be attachable to and detachable from the power source unit  110  via mechanical connection portions  111 ,  121 . When the atomization unit  120  and the power source unit  110  are mechanically connected to each other, a load  121 R in the atomization unit  120  is electrically connected to a power source  10  provided in the power source unit  110  via electric connection terminals (first connection portions)  111   t  and  121   t . That is, the electric connection terminals  111   t  and  121   t  form a connection portion through which the load  121 R and the power source  10  can be electrically connected to each other. 
     The atomization unit  120  includes an aerosol source to be sucked by a user, and the electric load  121 R that atomizes the aerosol source upon receipt of electric power from the power source  10 . 
     The load  121 R may be an element that can generate aerosol from the aerosol source using electric power from the power source. For example, the load  121 R may be a heating element such as a heater or an element such as an ultrasonic generator. Examples of the heating element may include a heating resistor, a ceramic heater, and an induction-heating-type heater. 
     Hereinafter, a more detailed example of the atomization unit  120  will be described with reference to  FIGS. 1 and 2 . The atomization unit  120  may include a reservoir  121 P, a wick  121 Q, and a load  121 R. The reservoir  121 P may be configured to reserve a liquid aerosol source. The reservoir  121 P may be a porous body made of a material such as a resin web, for example. The wick  121 Q may be a liquid retaining member that draws the aerosol source from the reservoir  121 P using a capillary phenomenon. The wick  121 Q can be made of, for example, glass fiber or porous ceramic. 
     The load  121 R heats the aerosol source retained in the wick  121 Q. The load  121 R is formed by, for example, a resistance heating element (for example, a heating wire) wound around the wick  121 Q. 
     Air flowing from an inlet  125 , which takes in outside air into a flow path, passes near the load  121 R in the atomization unit  120  through a flow path  122 A. The aerosol generated by the load  121 R flows toward the suction port  141  together with the air. Hereinafter, the flow path  122 A refers to a path between the inlet  125  and the suction port  141 , among paths through which a fluid can flow. That is, the flow path  122 A passes an air flow generated by user&#39;s suction. In the present embodiment, the flow path  122 A reaches the suction port  141  through the atomization unit  120  from the connection portion between the atomization unit  120  and the power source unit  110 . 
     In the present embodiment described above, the inlet  125  is provided at the connection portion  121  of the atomization unit  120 . Unlike the present embodiment, the inlet  125  may be provided at the connection portion  111  of the power source unit  110 . Unlike the present embodiment, the inlet  125  may be also provided at the connection portion  121  of the atomization unit  120  and the connection portion  111  of the power source unit  110 . In any case, the inlet  125  is provided at the connection portion between the atomization unit  120  and the power source unit  110 . 
     The aerosol source may be a liquid at normal temperature. Examples of the aerosol source to be used can include polyhydric alcohols. The aerosol source may contain a tobacco raw material or an extract derived from the tobacco raw material, which releases a smoking flavor component when it is heated. 
     The liquid aerosol source at normal temperature is described in detail as an example in the embodiment described above, but alternatively a solid aerosol source at normal temperature can be used. In this case, the load  121 R may be in contact with or close to the solid aerosol source to generate the aerosol from the solid aerosol source. 
     The atomization unit  120  may include a flavor unit (cartridge)  130  configured to be replaceable. The flavor unit  130  may include a cylindrical body  131  that accommodates the flavor source. The cylindrical body  131  may include a membrane member  133  and a filter  132  through which air or aerosol can pass. The flavor source may be provided in a space formed by the membrane member  133  and the filter  132 . 
     According to an example of a preferred embodiment, the flavor source in the flavor unit  130  adds the smoking flavor component to the aerosol generated by the load  121 R of the atomization unit  120 . The flavor added to the aerosol by the flavor source is carried to the suction port  141  of the flavor generation device  100 . 
     The flavor source in the flavor unit  130  may be solid at normal temperature. As an example, the flavor source includes a raw material piece of a plant material that adds the smoking flavor component to the aerosol. As the raw material piece included in the flavor source, a compact obtained by forming the tobacco material such as shredded tobacco or a tobacco raw material into a granular shape may be used. Alternatively, the flavor source may be a compact obtained by forming the tobacco material into a sheet shape. In addition, the raw material piece included in the flavor source may be formed by plants (for example, mint and herb) other than tobacco. The flavor source may be added with a flavoring agent such as menthol. 
     The flavor generation device  100  may include a mouthpiece having the suction port through which a user sucks a suction component. The mouthpiece may be configured to be attachable to and detachable from the atomization unit  120  or the flavor unit  130 , or may be configured integrally with them. 
     Hereinafter, a more detailed example of the power source unit  110  will be described with reference to  FIGS. 1, 3, and 4 . The power source unit  110  may include a case  113 , the power source  10 , a pressure sensor  20 , a first controller  50 , and a temperature sensor  160 . The power source  10 , the pressure sensor  20 , the first controller  50 , and the temperature sensor  160  may be provided in the case  113 . The case  113  may form a part of the outermost outer surface of the flavor generation device. 
     As described above, the power source  10  is configured to be electrically connected to or connectable to the load  121 R that atomizes the aerosol source. The power source  10  may be replaceable with respect to the power source unit  110 . The power source  10  may be, for example, a rechargeable battery such as a lithium-ion secondary battery. 
     The secondary battery may include a positive electrode, a negative electrode, a separator that separates the positive electrode and the negative electrode, and an electrolytic solution or an ionic liquid. The electrolytic solution or the ionic liquid may be, for example, a solution containing an electrolyte. In the lithium-ion secondary battery, the positive electrode is formed of, for example, a positive electrode material such as a lithium oxide, and the negative electrode is formed of, for example, a negative electrode material such as graphite. The electrolytic solution may be, for example, a lithium salt organic solvent. 
     The pressure sensor  20  is configured to output a value of a pressure change in the flavor generation device  100  generated by user&#39;s suction or blowing through the suction port  141 . Specifically, the pressure sensor  20  may be a sensor that outputs an output value (for example, a voltage value or a current value) according to air pressure that changes depending on a flow rate (that is, a user&#39;s puff operation) of air to be sucked toward the suction port side from the non-suction port side. The output value of the pressure sensor  20  may have a pressure dimension, or may have a flow rate or a flow velocity of air to be sucked instead of the pressure dimension. Examples of such a pressure sensor may include a capacitor microphone sensor and a known flow rate sensor. 
     The first controller  50  performs various controls of the flavor generation device  100 . For example, the first controller  50  may control the electric power to be supplied to the load  121 R. The flavor generation device  100  may include a first switch  172  that can electrically connect and disconnect the load  121 R and the power source  10  (see  FIG. 6 ). The first switch  172  is opened and closed by the first controller  50 . The first switch  172  may be formed by a MOSFET, for example. 
     When the first switch  172  is turned on, the electric power is supplied from the power source  10  to the load  121 R. On the other hand, when the first switch  172  is turned off, the supply of the electric power from the power source  10  to the load  121 R is stopped. The first switch  172  is turned on and off by the first controller  50 . 
     The power source unit  110  may include a request sensor capable of outputting an operation request signal that is a signal for requesting the operation of the load  121 R. The request sensor may be, for example, a push button  30  pressed by the user or the pressure sensor  20  described above. The first controller  50  acquires an operation request signal for the load  121 R and generates a command for operating the load  121 R. In a specific example, the first controller  50  outputs a command for operating the load  121 R to the first switch  172 , and the first switch  172  is turned on in response to the command. In this way, the first controller  50  may be configured to control the electric power to be supplied from the power source  10  to the load  121 R. When the electric power is supplied from the power source  10  to the load  121 R, the aerosol source is vaporized or atomized by the load  121 R. 
     Furthermore, the power source unit  110  may include a voltage sensor  150  that can acquire or estimate an output voltage of the power source  10 . In this case, the first controller  50  can perform a predetermined control according to the output value of the voltage sensor  150 . For example, the first controller  50  can detect or estimate a remaining amount of the power source  10  or abnormality of the power source  10  based on the output value of the voltage sensor  150 . When detecting a low remaining amount of the power source  10  or abnormality of the power source  10 , the first controller  50  may notify the user of the detected information by controlling a notification unit  40 . 
     The voltage sensor  150  may be configured to convert an analog voltage value of the power source  10  into a digital voltage value using a predetermined correlation and to output the digital voltage value. Specifically, the voltage sensor  150  may include an A/D converter that converts an analog input value into a digital output value. 
     In the present embodiment, the power source unit  110  may include a first resistor  152  and a second resistor  153  that are electrically connected in series with each other. The first resistor  152  is electrically connected to the power source  10  and is provided to connect a pair of electric terminals  111   t  to each other. One end of the second resistor  153  is connected to the first resistor  152 , and the other end of the second resistor  153  is connected to the voltage sensor  150 . 
     Electric resistance values of the first resistor  152  and the second resistor  153  are known. The electric resistance values of the first resistor  150  and the second resistor  152  may be preferably constant regardless of the state of the power source  10 . 
     The notification unit  40  issues a notification for notifying the user of various types of information. The notification unit  40  may be, for example, a light emitting element such as an LED. Alternatively, the notification unit  40  may be an acoustic element that generates sound or a vibrator that generates vibration. Furthermore, the notification unit  40  may be configured by any combination of the light emitting element, the acoustic element, and the vibrator. The notification unit  40  may be provided at any location of the flavor generation device  100 . In the present embodiment, the notification unit  40  may be built in the first controller  50 , or may be disposed at a location different from the first controller  50 . The notification unit  40  may be provided anywhere where the user can recognize the notification by the notification unit  40 . 
     The power source unit  110  may include a sensor capable of outputting a detected value or estimated value of the state of the power source  10 . The detected value or estimated value of the sensor is sent to the first controller  50 . The sensor capable of outputting the detected value or estimated value of the state of the power source  10  may be a first temperature sensor  160  that outputs the detected value or estimated value of a temperature of the power source  10 . The first temperature sensor  160  may be provided anywhere where the first temperature sensor  160  can output the detected value or estimated value of the temperature of the power source  10 . In the illustrated embodiment, the first temperature sensor  160  is built in the first controller  50 . 
     The sensor capable of outputting the detected value or estimated value of the state of the power source  10  may be a sensor that measures or estimates an internal resistance (a DC component of the impedance) of the power source  10  instead of the first temperature sensor  160 . As the sensor that measures or estimates the internal resistance of the power source  10 , the voltage sensor  150  may be used, for example. 
     In an aspect illustrated in  FIGS. 3 and 4 , the power source unit  110  includes a first member  300  and a second member  310  that cover the pressure sensor  20 , the temperature sensor  160 , and the first controller  50 . The first member  300  and the second member  310  are formed in a cylindrical shape, for example. The second member  310  is fitted to one end of the first member  300 . Aa cap  330  is provided at the other end of the first member  300 . The cap  330  may be formed with an opening  114  that is opened to the atmosphere. Thus, the inside of the first member  300  and the second member  310  is opened to the atmosphere. 
     The power source unit  110  may be configured to be connectable to a charging unit  200  that can charge the power source  10  (see  FIG. 8 ). A combination of the power source unit  110  and the charging unit  200  forms a flavor generation system of the present invention.  FIG. 8  is a diagram illustrating an electric circuit of the flavor generation system including the power source unit and the charging unit.  FIG. 9  is a block diagram of the charging unit. 
     When the charging unit  200  is connected to the power source unit  110 , the charging unit  200  is electrically connected to the power source  10  of the power source unit  110 . The charging unit  200  may include a current sensor  230 , a voltage sensor  240 , a second controller  250 , and a second temperature sensor  260 . 
     The charging unit  200  is electrically connected to the power source unit  110  by a pair of connection terminals  211   t . A pair of electric terminals of the power source unit  110  used to electrically connect the charging unit  200  may be the same as the pair of electric terminals  111   t  of the power source unit  110  used to electrically connect the load  121 R. Alternatively, the pair of electric terminals of the power source unit  110  used to electrically connect the charging unit  200  may be provided separately from the pair of electric terminals  111   t.    
     To simplify the structure of the flavor generation device  100 , the second controller  250  of the charging unit  200  may be configured to be incapable of communicating with the first controller  50  of the power source unit  110 . That is, a communication terminal for communicating between the second controller  250  of the charging unit  200  and the first controller  50  of the power source unit  110 , and a communication system including a receiver and a transmitter are unnecessary. In other words, in a connection interface with the charging unit  200 , the power source unit  110  has only two electric terminals, one for a main positive bus and the other for a main negative bus. In this case, the power source unit  110  and the charging unit  200  are electrically connected to each other only by the main positive bus and the main negative bus. 
     When an external power source  210  is an AC power source, the charging unit  200  may include an inverter (AC/DC converter) that converts AC into DC. The current sensor  230  is a sensor that acquires a value of a charging current supplied from the charging unit  200  to the power source  10 . The voltage sensor  240  is a sensor that acquires a voltage between the pair of electric terminals of the charging unit  200 . In other words, the voltage sensor  240  acquires a potential difference applied between the pair of connection terminals  111   t  of the power source unit. 
     The second controller  250  is configured to control a charge of the power source  10 . The second controller  250  may control the charge of the power source  10  using output values from the temperature sensor  260 , the current sensor  230  and/or the voltage sensor  240 . Note that the charging unit  200  may further include a voltage sensor that acquires DC voltage output from the inverter and a converter that can increase and/or decrease a DC voltage output from the inverter or the external power source  210 . 
     The power source unit  110  may include a second switch  174  between the power source  10  and the electric connection terminals (first connection portions)  111   t  and  121   t . The second switch  174  is opened and closed by the first controller  50 . The second switch  174  may be formed by a MOSFET, for example. The second switch  174  is turned on and off by the first controller  50 . 
     When the second switch  174  is turned on, the charging current can flow to the power source  10  from the charging unit  200 . When the second switch  174  is turned off, the charging current can hardly flow to the power source  10  from the charging unit  200 . That is, even when the charging unit  200  is connected to the power source  110 , the first controller  50  can temporarily or permanently stop the charge of the power source  10  with the second switch  174 . 
     The charging unit  200  may include a conversion unit  290  that can convert a voltage or a current of the input electric power and output the converted voltage or current. The second controller  250  is configured to be capable of adjusting the value of the voltage or current to be output from the conversion unit  290  by operating the conversion unit  290 . Thus, the second controller  250  can adjust the charging current for charging the power source  10 . 
     The first controller  50  of the power source unit  110  may be configured to be capable of determining whether the charging unit  200  is connected. The first controller  50  can determine, based on the change in a voltage drop amount in the second resistor  153  described above, whether the charging unit  200  is connected. 
     The voltage drop amount in the second resistor  153  differs depending on a case where nothing is connected to the pair of electric terminals  111   t  and a case where the external unit such as the charging unit  200  or the atomization unit  120  is connected to the pair of electric terminals  111   t . Accordingly, the first controller  50  can detect the connection of the external unit such as the charging unit  200  or the atomization unit  120  by acquiring the voltage drop amount in the second resistor  153 . 
     For example, when detecting a high-level voltage value V wake  at the second resistor  153 , the first controller  50  can estimate that the charging unit  200  is not connected to the connection terminals  111   t . In addition, when detecting a low-level voltage value V wake , the first controller  50  can estimate that the charging unit  200  is connected to the connection terminals  111   t.    
     More specifically, in a state where the charging unit  200  is not connected to the connection terminals  111   t , a current flows from the power source  10  to the first controller  50  via the first resistor  152  and the second resistor  153 . Accordingly, since the voltage drop occurs in the second resistor  153  due to the current flowing through the second resistor  153 , the first controller  50  detects a high-level voltage value V wake  at the second resistor  153 . On the other hand, among the pair of electric terminals  111   t , when the main negative bus of the charging unit  200  connected between the first resistor  152  and the second resistor  153  falls to the ground potential due to grounding, a portion between the first resistor  152  and the second resistor  153  falls to the ground potential due to connection of the charging unit  200  to the connection terminals  111   t . Therefore, since the current does not flow through the second resistor  153  in a state where the charging unit  200  is connected to the connection terminals  111   t , the first controller  50  detects a low-level voltage value V wake . 
     Instead of the aspect described above, the first controller  50  may detect the connection of the charging unit  200 , for example, based on a change in potential difference between the pair of connection terminals  111   t.    
     (Charge Control of Power Source) 
     In the present embodiment, both of the first controller  50  of the power source unit  110  and the second controller  250  of the charging unit  200  are configured to be capable of controlling the charge of the power source  10 , in particular, the charging speed of the power source  10 . That is, the first controller  50  can control the charging speed by operating the second switch  174 . The charging speed can be expressed using a charge rate (a so-called C-rate) or a value of electric power per unit time for charging the power source  10 . Here, the control of the charging speed includes setting the charging speed to “0.” That is, the control of the charging speed includes stopping the charge. 
     For example, the first controller  50  can control the charging speed by repeating opening and closing of the second switch  174  at the desired time interval. The first controller  50  can stop the charge by maintaining the second switch  174  in an open state. In any case, it will be apparent that the charging speed is slower than that in a case where the second switch  174  is maintained in a closed state. 
     The first controller  50  preferably controls the charging speed based on the output value of the sensor capable of outputting the detected value or estimated value of the state of the power source  10 . Such a sensor may be, for example, the first temperature sensor  160  described above. In this case, the first controller  50  can control, based on the temperature of the power source  10 , whether to set the charging speed to “0,” by operating the second switch  174 . 
       FIG. 10  is a map illustrating an example of a correlation between a temperature and a charging speed of the power source. As illustrated in  FIG. 10 , in a case where the output value of the first temperature sensor  160  is within a predetermined temperature range (belongs to a charge permissible section of  FIG. 10 ), the first controller  50  may close the second switch  174 . When the second switch  174  is closed, the charge of the power source  10  is permitted, whereby the charging speed becomes larger than “0.” In a case where the output value of the first temperature sensor  160  is outside the predetermined temperature range (belongs to a charge stop section of  FIG. 10 ), the first controller  50  may open the second switch  174 . When the second switch  174  is opened, the charge of the power source  10  is stopped, whereby the charging speed becomes “0.” 
     Specifically, the first controller  50  may be configured to open the second switch  174  in a case where the output value of the first temperature sensor  160  is equal to or lower than a first predetermined temperature, which causes solidification of the electrolytic solution or the ionic liquid, or in a case where the temperature of the power source  10  is estimated to be equal to or lower than the first predetermined temperature based on the output value of the first temperature sensor  160 . In this way, the power source  10  can be protected even in the temperature range which causes solidification of the electrolytic solution or the ionic liquid of the power source  10 . 
     The first predetermined temperature may be, for example, 0° C. as illustrated in  FIG. 10 . When the temperature of the power source  10  becomes equal to or lower than 0° C., moisture in the power source  10 , e.g., moisture in the electrolytic solution may be solidified. Under such circumstances, charging the power source  10  easily causes acceleration of the deterioration of the power source  10 . Accordingly, in such a temperature range, the charge of the power source  10  is preferably stopped. 
     In addition, the first controller  50  may be configured to open the second switch  174  in a case where the output value of the first temperature sensor  160  is equal to or lower than a second predetermined temperature at which electrodeposition occurs on the electrode in the power source  10 , or in a case where the temperature of the power source  10  is estimated to be equal to or lower than the second predetermined temperature based on the output value of the first temperature sensor  160 . 
     In particular, in a case where the power source  10  is a lithium-ion secondary battery, when a high load is applied to the power source  10  during charging at low temperature, metallic lithium may be deposited (electrodeposited) on a surface of the negative electrode. Therefore, the charge is preferably stopped. Here, since the second predetermined temperature may depend on the type of the lithium-ion secondary battery, it is necessary to specify the second predetermined temperature by an experiment in advance. The second predetermined temperature may be the same as or different from the first predetermined temperature. 
     Furthermore, the first controller  50  may be configured to open the second switch  174  in a case where the output value of the first temperature sensor  160  is equal to or higher than a third predetermined temperature at which a change in structure or composition of the electrode occurs in the power source  10 , or in a case where the temperature of the power source  10  is estimated to be equal to or higher than the third predetermined temperature based on the output value of the first temperature sensor  160 . 
     When the temperature of the power source  10  becomes extremely high, a change in structure or composition of the electrode may occur. Therefore, the first controller  50  preferably stops the charge. An example of the change in structure or composition of the electrode is aggregation of an active material, conductive additive, and binder or detachment of an active material, conductive additive, and binder from the electrode. The third predetermined temperature may be, for example, 60° C. 
     The information about the correlation (first correlation) between the temperature and the charging speed of the power source as illustrated in  FIG. 10  may be stored in a memory in the first controller  50 . 
     Instead of the above-described aspect, the first controller  50  may control the charging speed based on the output value of the sensor that measures or estimates the internal resistance of the power source  10 . That is, the sensor capable of outputting the detected value or estimated value of the state of the power source  10  may be a sensor that measures or estimates the internal resistance of the power source  10 , e.g., the voltage sensor  150 . When the internal resistance of the power source  10  increases, heat generation of the power source  10  increases during charging and discharging. Even in that case, the power source  10  can be protected by controlling the charging speed based on the internal resistance of the power source  10  as described above, for example, by reducing the charging speed when the internal resistance of the power source  10  increases. 
     In addition, the second controller  250  can control the charging speed by operating the conversion unit  290 . It will be apparent to those skilled in the art that the charging speed can be controlled in a case where the conversion unit  290  performs a current control mode that controls CV charging (described later) and an output current, as an example. That is, the second controller  250  can adjust the value of the voltage or current to be output from the conversion unit  290 . Here, the control of the charging speed includes setting the charging speed to “0.” That is, the control of the charging speed also includes stopping the charge. 
     The conversion unit  290  may be configured to be capable of performing a first charging mode and a second charging mode which are different in the charging speed. The second charging mode may be a mode in which a value of the electric power or current per unit time that can be output by the conversion unit  290  is greater than that in the first charging mode. In this case, the second charging mode is also referred to as a “quick charging mode.” Note that, to distinguish from the second charging mode, the first charging mode is also referred to as a “normal charging mode.” 
     In addition, the second controller  250  may be configured to be capable of performing a third mode in which a value of the electric power or current per unit time that can be output by the conversion unit  290  is smaller than that in the first charging mode. In an example illustrated in  FIG. 11 , the third mode is performed in a state where a remaining amount of the power source  10  is decreased significantly, i.e., in an over-discharge state or a deep discharged state. The over-discharge state or the deep discharged state may be a state in which the voltage value of the power source  10  is lower than a discharge termination voltage. In the over-discharge state or the deep discharged state, the power source  10  is easily damaged. Therefore, the second controller  250  needs to charge the power source  10  at a low speed and attempt to recover the power source  10  (return to the state where the voltage value is equal to or higher than the discharge termination voltage). 
     The second controller  250  preferably controls the charging speed based on the output value of the second temperature sensor  260 . That is, the second controller  250  controls the charging speed as described above, i.e., selects the mode based on the temperature of the charging unit  200 . 
       FIG. 11  is a map illustrating an example of a correlation between a temperature and a charging speed of the charging unit  200 . As illustrated in  FIG. 11 , the second controller  250  causes the conversion unit  290  to perform the second charging mode in a case where the output value of the second temperature sensor  260  is equal to or higher than a first threshold. On the other hand, the second controller  250  causes the conversion unit  290  to perform the first charging mode in a case where the output value of the second temperature sensor  260  is lower than the above-described first threshold. 
     In  FIGS. 11 and 12 , the charging speed is expressed using a C-rate. In general, the charging speed at which the power source  10  is charged to a fully charged state from the discharge termination state for one hour can be represented by 1.0 C as a reference. In a case of a charge rate higher than 1.0 C, the charge is performed faster than 1.0 C. In a case of charge rate lower than 1.0 C, the charge is performed slower than 1.0 C. As an example, when the charge is performed at a charge rate of 2.0 C, the charge is performed at twice the charge rate of 1.0 C. When the charge is performed at a charge rate of 0.5 C, the charge is performed at half the charge rate of 1.0 C. In the present embodiment, as an example, the charging speed of 0.5 C is used in the first charging mode, the charging speed of 2.0 C is used in the second charging mode, and the charging speed of 0.05 C is used in the third charging mode. 
     The first threshold may be, for example, 10° C. Therefore, the second controller  250  does not perform the quick charging mode at low temperature to reduce the load applied to the power source  10 , which can prevent a phenomenon such as electrodeposition. 
     More specifically, the second controller  250  may select one of the first charging mode and the second charging mode based on the other conditions, in a case where the output value of the second temperature sensor  260  is equal to or higher than the above-described first threshold. In the present embodiment, the second controller  250  is configured to be capable of adjusting a value of the voltage or current to be output from the conversion unit  290  by operating the conversion unit  290 , based on a value related to the remaining amount of the power source  10  and the output value of the second temperature sensor  260 . 
     The value related to the remaining amount of the power source  10  is not limited to a particular value, but may be, for example, the voltage of the power source  10 . The voltage of the power source  10  can be acquired by the voltage sensor  240 . 
     In this case, the second controller  250  may be configured to perform only constant current charging (CC charging) of the constant current charging and constant voltage charging (CV charging) in a case where the output value of the temperature sensor  260  is smaller than the first threshold. Note that the charging speed of the constant current charging may be any value between 0.5 to 1.0 C, and, as an example, may be 1.0 C. The second controller  250  may perform the constant current charging and the constant voltage charging in a case where the output value of the temperature sensor  260  is equal to or higher than the first threshold. More specifically, in a case where the output value of the temperature sensor  260  is equal to or higher than the first threshold and in a case where the voltage of the power source  10  acquired by the voltage sensor  240  is equal to or higher than a switching voltage, the second controller  250  may perform the constant voltage charging. In a case where the output value of the temperature sensor  260  is equal to or higher than the first threshold and in a case where the voltage of the power source  10  acquired by the voltage sensor  240  is lower than a switching voltage, the second controller  250  may perform the constant current charging. Here, the switching voltage may be, for example, 4.2 V. 
     In this way, in the correlation (second correlation) illustrated in  FIG. 11 , at low temperature, a full charge capacity of the power source  10  is decreased, and therefore the second controller  250  performs only the constant current charging without performing the constant voltage charging. In addition, at low temperature, the internal resistance of the power source  10  increases, and the voltage of the power source  10  acquired by the voltage sensor  240  is higher than a true value. Therefore, overcharge of the power source  10  can be prevented by omitting the CV charging. 
     Instead of the correlation illustrated in  FIG. 11 , the second controller  250  may control the charging speed based on a correlation illustrated in  FIG. 12 . In the correlation illustrated in  FIG. 12 , both of the constant current charging (CC charging) and the constant voltage charging (CV charging) are performed even when the output value of the temperature sensor  260  is lower than the first threshold. Note that the switching voltage in a case where the output value of the temperature sensor  260  is lower than the first threshold is smaller than the switching voltage in a case where the output value of the temperature sensor  260  is equal to or higher than the first threshold. That is, the second controller  250  may be configured so that the switching value which is a value related to the remaining amount of the power source when the constant current charging is switched to the constant voltage charging in a case where the output value of the temperature sensor  260  is lower than the first threshold, e.g., a switching value (switching voltage) of the voltage value of the power source  10  is smaller than the switching value in a case where the output value of the temperature sensor  260  is equal to or higher than the first threshold. In this way, the constant voltage charging can be performed before charge completion, even at low temperature at which the full charge capacity of the power source  10  is decreased. Furthermore, the power source  10  can be charged to near full charge while avoiding overcharge. 
     The information about the correlation (second correlation) between the temperature and the charging speed of the charging unit  200  as illustrated in  FIG. 11 or 12  may be stored in a memory in the second controller  250 . 
     As described above, in the control of the charging speed, an object to be operated by the first controller  50  is different from an object to be operated by the second controller  250 . In this way, the first controller  50  and the second controller  250  share the control of the charging speed by operating the respective objects different from each other. 
     That is, the charging speed is controlled by both of the first controller  50  and the second controller  250 . More specifically, the second controller  250  may adjust (operate) a value of the voltage or current to be output from the conversion unit  290  by operating the conversion unit  290  and the first controller  50  may control (operate) whether to set the charging speed to 0″ by operating the second switch  174 . 
     Out of determinations to be made in the charge of the power source  10 , the number of first options for the determination to be made by the first controller  50  is preferably smaller than the number of second options for the determination to be made by the second controller  250 . For example, as illustrated in  FIG. 10 , the first controller  50  has two options (first options): to turn on or to turn off the second switch  174  based on the output value of the first temperature sensor  160 . On the other hand, as illustrated in  FIGS. 11 and 12 , the second controller  250  has more than two options: to perform the first charging mode, the second charging mode, the third charging mode, the CV charging, or the CC charging based on the output value of the second temperature sensor  260 . The first controller  50  need not to provide high performance by allowing the external unit other than the power source unit  110 , i.e., the charging unit  200  to have many options, whereby a configuration of the power source unit  110  and consequently the flavor generation device  100  can be simplified. In the flavor generation device  100  that is carried routinely by the user and that is held by a mouth of the user in use, the above-described effect is particularly preferable. 
     (Control Flow 1 by Second Controller of Charging Unit) 
       FIG. 13  is a flowchart illustrating an example of a control flow by the second controller  250  of the charging unit  200 . Firstly, the second controller  250  determines whether the charging unit  200  is connected to the power source unit  110  (step S 300 ). The second controller  250  waits until the charging unit  200  is connected to the power source unit  110 . 
     The connection between the charging unit  200  and the power source unit  110  can be detected by a known method. For example, when a change in voltage between the pair of electric terminals  211   t  of the charging unit  200  is detected by the voltage sensor  240 , the second controller  250  can determine whether the charging unit  200  is connected to the power source unit  110 . Instead of the voltage sensor  240 , a mechanical switch may be used in which the output is switched between the connected state and the disconnected state between the charging unit  200  and the power source unit  110 . 
     When the charging unit  200  is connected to the power source unit  110 , the second controller  250  acquires an output value of the second temperature sensor  260  and a voltage (V BATT ) of the power source  10  (steps S 302  and S 303 ). Either of the output value of the second temperature sensor  260  or the voltage (V BATT ) of the power source  10  may be acquired first, or they may be acquired at the same time. The second controller  250  can acquire the voltage (V BATT ) of the power source  10  from the voltage sensor  240 . Note that when the voltage of the power source  10  is acquired by the voltage sensor  240 , the first controller  50  of the power source unit  110  maintains the second switch  174  in the closed state (“on” state). 
     Next, the second controller  250  sets the charging mode based on the output value of the second temperature sensor  160  (step S 304 ). Specifically, the second controller  250  sets the charging speed (charging mode) of the power source  10  based on the correlation (second correlation) for setting the charging conditions of the power source  10  as illustrated in  FIG. 11 or 12 . Preferably, the second controller  250  sets the charging speed (charging mode) based on both of the output value of the second temperature sensor  160  and the value related to the remaining amount of the power source  10 , e.g., the voltage (V BATT ) of the power source  10 . 
     Subsequently, the second controller  250  determines, as necessary, which one of the constant voltage charging and the constant current charging is to be performed (step S 306 ). Specifically, when the voltage (V BATT ) of the power source  10  is lower than the above-described switching voltage, the second controller  250  supplies the current to the power source unit  110  by the constant current charging (step S 308 ). 
     As the charge of the power source  10  proceeds, the voltage of the power source  10  increases. Accordingly, after performing the constant current charging for a certain period, the second controller  250  acquires an output value of the second temperature sensor  260  and a voltage (V BATT ) of the power source  10  again (steps S 302  and S 303 ). Then, the second controller  250  sets the charging speed (charging mode) again based on both of the output value of the second temperature sensor  160  and the voltage (V BATT ) of the power source  10 . Note that the charging speed can be set by adjusting a value of the voltage or current to be output from the conversion unit  290  by operating the conversion unit  290 . Thereafter, as described above, the second controller  250  determines, as necessary, which one of the constant voltage charging and the constant current charging is to be performed (step S 306 ). 
     When the voltage (V BATT ) of the power source  10  is equal to or higher than the above-described switching voltage, the second controller  250  supplies the current to the power source unit  110  by the constant voltage charging (step S 310 ). In the constant voltage charging, as the charge of the power source  10  proceeds, a difference between the charging voltage and the voltage of the power source  10  is reduced, whereby the charging current decreases. 
     When the charging current is larger than the charging completion current (step S 312 ), the second controller  250  acquires an output value of the second temperature sensor  260  and a voltage (V BATT ) of the power source  10  again (steps S 302  and S 303 ). Then, the second controller  250  sets the charging speed (charging mode) again based on both of the output value of the second temperature sensor  160  and the voltage (V BATT ) of the power source  10 . 
     When the charging current is equal to or smaller than the charging completion current during the constant voltage charging (step S 312 ), the second controller  250  determines that the charge has been completed, and stops the charge of the power source  10  (step S 314 ). 
     As described above, the second controller  250  preferably acquires not only the output value of the temperature sensor  260  but also the voltage (V BATT ) of the power source  10 , and sets the charging mode also based on the voltage of the power source  10 . The second controller  250  can use the value related to the remaining amount of the power source instead of the voltage of the power source  10 . That is, in step S 304 , the second controller  250  may adjust a value of the voltage or current to be output from the conversion unit  290  by operating the conversion unit  290 , based on the value related to the remaining amount of the power source  10  and the output value of the second temperature sensor  260 . 
     In the control flow described above, the second controller  250  periodically acquires the output value of the second temperature sensor  260 , and selects the charging mode based on the acquired output value. Alternatively, the second controller  250  may select the charging mode using the output value of the second temperature sensor  260  acquired once after the power source unit  110  is connected. That is, the second controller  250  may acquire the output value of the second temperature sensor  260  only once in the determination of the charging speed. In this case, the second controller  250  determines the charging mode based on the correlation illustrated in  FIG. 11 or 12  according to a change in voltage of the power source  10 , assuming that the temperature of the charging unit  200  is not changed. In this case, after step S 308 , the process returns to step S 306  rather than to step S 302 . When it is determined as No in step S 312 , the process returns to S 312  rather than to step S 302 . Accordingly, the control flow can be simplified. 
     In the control flow illustrated in  FIG. 13 , the second controller  250  sets the charging mode in step S 304  before determining, in step S 306 , which one of the constant voltage charging and the constant current charging is to be performed. Since the second correlation used in step S 304  specifies the charging speed in the constant current charging, the charging mode may be instead determined in step S 304  after it is determined, in step S 306 , that the constant current charging is to be performed. 
     (Control by First Controller in Charging Mode) 
       FIG. 14  is a flowchart illustrating an example of a control flow by the first controller of the power source unit. 
     Firstly, the first controller  50  determines whether the charging unit  200  is connected to the power source unit  110  (step S 402 ). The connection of the charging unit  200  to the power source unit  110  can be detected by the above-described method. 
     Subsequently, the first controller  50  turns on the second switch  174  (step S 403   a ) to electrically connect the power source unit  110  and the charging unit  200 , so that the second controller  250  can acquire the voltage (V BATT ) of the power source  10  in step S 303  described above. Then, the first controller  50  turns off the second switch  174  to electrically disconnect the power source unit  110  from the charging unit  200  (step S 403   b ). 
     When the first controller  50  detects the connection of the charging unit  200  to the power source unit  110 , the first controller  50  acquires an output value of the first temperature sensor  160  provided in the power source unit (step S 404 ). 
     Next, the first controller  50  sets the charging speed based on the first correlation for setting the charging conditions of the power source based on the output value of the first temperature sensor  160  (steps S 406 , S 407 , and S 408 ). The first correlation is as described with reference to  FIG. 10 . 
     The first controller  50  preferably controls the charging speed to be set to “0” or not by operating the second switch  174 . More specifically, the first controller  50  controls the charging speed to be set to “0” or not by operating the second switch  174 , based on the output value of the first temperature sensor  160 . 
     In the flow illustrated in  FIG. 14 , the first controller  50  opens the second switch  174  (steps S 406  and S 408 ) in a case where the temperature of the power source  10  is equal to or lower than the first predetermined temperature or in a case where the temperature of the power source  10  is estimated to be equal to or lower than the first predetermined temperature based on the output value of the first temperature sensor  160 . Here, the first predetermined temperature may be, for example, 0° C. 
     In addition, the first controller  50  opens the second switch  174  (steps S 406  and S 408 ) in a case where the temperature of the power source  10  is equal to or higher than the third predetermined temperature, or in a case where the temperature of the power source  10  is equal to or higher than the third predetermined temperature based on the output value of the first temperature sensor  160 . 
     The first controller  50  closes the second switch  174  (step S 407 ) in a case where the output value of the first temperature sensor  160  is within a predetermined temperature range, e.g. within a range of 0 to 60° C. In this manner, the first controller  50  can permit the charge only in a case where the temperature of the power source  10  is in a temperature conditions suitable for the charge. 
     During the charge of the power source  10 , the first controller  50  detects whether the charging unit  200  is disconnected. In a state where the charging unit  200  is connected, the first controller  50  maintains the second switch  174  in the closed state except for the case where the voltage of the power source  10  is acquired by the voltage sensor  150 . This can maintain a state of being capable of charging the power source  10 . 
     In the flows illustrated in  FIGS. 13 and 14 , the first controller  50  of the power source unit  110  and the second controller  250  of the charging unit  200  share the control of the charging speed of the power source  10 . The first controller  50  and the second controller  250  are configured to control the charging speed based on the output values of the first temperature sensor  160  and the second temperature sensor  260 , respectively, i.e., based on values related to the same physical quantity. 
     Specifically, the first controller  50  and the second controller  250  are configured to control the charge of the power source  10  based on the first correlation and the second correlation as illustrated in  FIGS. 10 to 12 . The first controller  50  and the second controller  250  are preferably configured to control the charge of the power source  10  by preferentially using the first correlation out of the first correlation and the second correlation. That is, the first correlation is preferably a correlation for determining whether to set the charging speed to “0”, as illustrated in  FIG. 10 . In this way, the second controller  250  adjusts the charging speed to a value larger than “0,” and the first controller  50  determines whether to set the charging rate to “0.” 
     Since the first temperature sensor  160  is disposed to be closer to the power source  10  than the second temperature sensor  260 , the first temperature sensor  160  can acquire more accurately the temperature of the power source  10 . On the other hand, increases in weight and size of the power source unit  110  are not preferable in view of article characteristics of the flavor generation device  100  that is carried routinely by the user and that is held by a mouth of the user in use. Then, the second controller  250  makes a primary determination of the charging speed with many options based on the output value of the second temperature sensor  260 . The first controller  50  makes a secondary (final) determination of the charging speed with few options based on the output value of the first temperature sensor. 
     In this way, the objects to be operated for the charge of the power source  10  are properly divided into the power source unit  110  and the charging unit  200 , whereby more sophisticated control of the charging speed is made possible according to the state (environment) of the power source, for example. 
     Furthermore, the first controller  50  and the second controller  250  may control the charge of the power source  10  without communicating with each other. Therefore, a configuration of the power source unit  110  can be simplified. Even in such a case, the first controller  50  and the second controller  250  share the control of the charging speed of the power source, whereby sophisticated control of the charging speed is made possible. 
     The sophisticated control of the charging speed is advantageous in the following other points. Firstly, since the power source  10  can be protected, the lifetime of the power source  10  is increased. Secondly, since the electric power supplied from the charging unit  200  is used for the charge of the power source  10  without being wasted as compared with a case where the temperature of the power source  10  is low or high or a case where the internal resistance of the power source  10  is high, the charging efficiency is improved. That is, a flavor generation system with sophisticated control of the charging speed, a method of controlling the flavor generation system, and a program have an energy-saving effect. 
     (Control Flow 2 by Second Controller of Charging Unit) 
       FIG. 15  is a flowchart illustrating another example of a control flow by the second controller  250  of the charging unit  200 . Hereinafter, the same reference numerals are denoted for steps similar to steps illustrated in  FIG. 13 , and the description thereof will be omitted. 
     Firstly, the second controller  250  determines whether the charging unit  200  is connected to the power source unit  110  (step S 300 ). The second controller  250  waits until the charging unit  200  is connected to the power source unit  110 . 
     When the charging unit  200  is connected to the power source unit  110 , the second controller  250  applies a test current toward the power source unit  110 , and estimates or measures an internal resistance of the power source  10  (step S 301 ). It will be apparent to those skilled in the art that the internal resistance of the power source  10  can be obtained by dividing a value of the voltage applied to the power source unit  110  when the test current is applied by the value of the test current. In this way, the state of the power source  10  can be estimated. The second controller  250  acquires a voltage (V BATT ) of the power source  10  (step S 303 ). Note that, in a period from step S 301  to step S 303 , the first controller  50  of the power source unit  110  performs step S 403   a  and step S 403   b  described above to maintain the second switch  174  in the closed state (“on” state). 
     Next, the second controller  250  sets the charging mode based on the internal resistance of the power source  10  (step S 304 ). 
     Subsequently, the second controller  250  determines, as necessary, which one of the constant voltage charging and the constant current charging is to be performed (step S 306 ). Specifically, when the voltage (V BATT ) of the power source  10  is lower than the above-described switching voltage, the second controller  250  supplies the current to the power source unit  110  by the constant current charging (step S 308 ). Similarly, when the voltage (V BATT ) of the power source  10  is equal to or higher than the above-described switching voltage, the second controller  250  supplies the current to the power source unit  110  by the constant voltage charging (step S 310 ). Note that the subsequent steps are the same as those in  FIG. 13 , and the description thereof will be omitted. 
     Even in a case where the second controller  250  of the charging unit  200  performs the steps illustrated in  FIG. 15 , the control flow by the first controller  50  may be substantially similar to the steps illustrated in  FIG. 14 . However, in a period from when the second controller  250  starts to apply the test current until the second controller  250  acquires the voltage of the power source  10 , i.e., in the period from step S 301  to step S 303 , the first controller  50  operates the second switch  174  to maintain it in an “on” state. Accordingly, a period from step S 403   a  to S 403   b  illustrated in  FIG. 14  needs to be increased. 
     As illustrated in  FIG. 15 , the second controller  250  may set the charging speed based on an output value of a sensor that acquires a value having a physical quantity other than the temperature, instead of the output value of the second temperature sensor  260 . Even in such a case, the first controller  50  may set the charging speed based on the output value of the first temperature sensor  160 . In this way, the first controller  50  and the second controller  250  can set the charging speed based on the output values of sensors that output values related to physical quantities different from each other, respectively. 
     Since the first controller  50  is disposed to be close to the power source  10 , the first controller  50  can acquire more accurately the temperature of the power source  10 . On the other hand, increases in weight and size of the power source unit  110  are not preferable in view of article characteristics of the flavor generation device  100  that is carried routinely by the user and that is held by a mouth of the user in use. Then, the second controller  250  makes a primary determination of the charging speed with many options based on the internal resistance of the power source  10  that can be acquired accurately even away from the power source  10 . The first controller  50  makes a secondary (final) determination of the charging speed with few options based on the temperature of the power source  10 . 
     In this way, the objects to be operated for the charge of the power source  10  are properly divided into the power source unit  110  and the charging unit  200 , whereby more sophisticated control of the charging speed is made possible according to the state (environment) of the power source, for example. 
     The sophisticated control of the charging speed is advantageous in the following other points. Firstly, since the power source  10  can be protected, the lifetime of the power source  10  is increased. Secondly, since the electric power supplied from the charging unit  200  is used for the charge of the power source  10  without being wasted as compared with a case where the temperature of the power source  10  is low or high or a case where the internal resistance of the power source  10  is high, the charging efficiency is improved. That is, a flavor generation system with sophisticated control of the charging speed, a method of controlling the flavor generation system, and a program have an energy-saving effect. 
     (Discharge Control of Power Source) 
     An aspect in which the charge of the power source  10  is controlled by both of the first controller  50  and the second controller  250  has been described in detail with reference to  FIGS. 10 to 15 . Such a concept can be also applied to an aspect in which the discharge of electric power from the power source  10  is controlled by both of the first controller  50  and the second controller  250 . Here, the discharge of electric power from the power source  10  is performed in a case where an external unit other than the charging unit  200 , e.g., the atomization unit  120  is connected to the connection terminals  111   t  of the power source unit  110 . In this case, the external unit such as the atomization unit  120  preferably includes a controller that can control the discharge of electric power from the power source  10  to the external unit, and specifically, that can control the discharging speed. 
     An object to be operated by the controller provided in the external unit such as the atomization unit  120  may be different from the object to be operated by the first controller  50  of the power source unit  110 . In this case, the first controller  50  controls the discharging speed of the power source by operating a first object provided in the power source unit  110  including the power source  10 , and another controller provided in the external unit further controls the discharging speed by operating a second object. The discharging speed can be controlled by the above-described controllers based on similar concepts to the correlations ( FIGS. 10 to 12 ) used for the charge control. 
     In addition, in this case, out of determinations to be made in the discharge, the number of first options for the determination to be made by the first controller  50  is preferably smaller than the number of second options for the determination to be made by the controller in the external unit. For example, as illustrated in  FIG. 10 , the first controller  50  determines whether to set the discharging speed to “0” based on the output value of the first temperature sensor  160 . In this case, the number of options for the determination to be made by the first controller  50  is “2.” 
     In a case where the external unit is the atomization unit, the controller in the external unit may perform feedback control of the temperature of the load  121 R. Specifically, the controller in the atomization unit acquires the temperature of the load  121 R and performs the feedback control so that the temperature of the load  121 R is within a desired temperature range. The feedback control can be performed by pulse width modulating (PWM) or pulse frequency modulating (PFM) a current pulse or voltage pulse of the discharging current from the power source  10  to the atomization unit  130 , for example. 
     Note that the desired temperature range of the feedback control need not always be fixed, and may change according to the progress of heating of the aerosol source by the load  121 R. Alternatively, the atomization unit  120  includes a plurality of load  121 R, and the loads  121 R to which the feedback control is applied may be changed according to the progress of heating of the aerosol source, or the number of the load  121 R to which the feedback control is applied may be increased or decreased. Instead of the feedback control, feed forward control may be used. 
     Here, the feedback control such as pulse width modulation (PWM) control or pulse frequency modulation (PFM) control can be performed by so-called PID control, for example. In the PID control, a number of determinations are required to calculate proportional control, an integral gain (I gain), and a derivative gain (D gain). Accordingly, the number of first options for the determination to be made by the first controller  50  is smaller than the number of second options for the determination to be made by the controller in the atomization unit. Similar to the sophisticated control of the charging speed, a flavor generation system with sophisticated control of the discharging speed, a method of controlling the flavor generation system, and a program have an energy-saving effect. 
     Note that, in the present embodiment, out of determinations to be made in the discharge, the number of first options for the determination to be made by the first controller  50  is smaller than the number of second options for the determination to be made by the controller in the external unit. Alternatively, out of determinations to be made in the discharge, the number of first options for the determination to be made by the first controller  50  may be greater than the number of second options for the determination to be made by the controller in the external unit. For example, in a case where the external unit is the atomization unit, since the first controller  50  makes the determination with many options, a configuration of the second controller  250  can be simplified. Accordingly, the cost of the atomization unit  130  that requires replacement according to the depletion of the aerosol source can be reduced. 
     (Program and Storage Medium) 
     The first controller  50  or the second controller  250  can perform any method described above. That is, the first controller  50  or the second controller  250  may include a program that causes the flavor generation system to execute the above-described method, and a storage medium in which such a program is stored. 
     OTHER EMBODIMENTS 
     Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the invention is limited to the description and drawings constituting a part of the disclosure. From the disclosure, various alternative embodiments, example, and operational techniques will be apparent to those skilled in the art. 
     In the embodiments described above, for example, the flavor generation device  100  includes both of the aerosol source for generating the aerosol and the flavor source including the tobacco raw material and/or the extracts derived from the tobacco raw material for generating the smoking flavor component. Alternatively, the flavor generation device  100  may include only one of the aerosol source and the flavor source. 
     Note that in this specification, it should be noted that the term “flavor” may be defined as a broad concept including a smoking flavor component generated from a flavor source or an aerosol source, or a smoking flavor component derived from the flavor source or the aerosol source. 
     In the embodiments described above, the electric load  121 R is configured to act on the aerosol source to vaporize or atomize the aerosol source. Alternatively, the electric load  121 R may be configured to heat the flavor source or the flavor unit to release the flavor. In this case, the power source  10  is configured to be electrically connected to or connectable to the load  121 R that heats the flavor source. Furthermore, the electric load  121 R may be configured to heat both of the aerosol source and the flavor source. 
     Furthermore, in the control flow by the first controller  50  as described above, the first controller  50  determines whether to set the charging speed to “0” (also, see the correlation in  FIG. 10 ). Alternatively, the first controller  50  may determine whether the charging speed is increased or decreased. For example, the first controller  50  may set the charging speed in a case where the temperature of the power source  10  is outside the predetermined temperature range slower than that in a case where the temperature of the power source  10  within the predetermined temperature range. That is, the first controller  50  may be configured to control the amount of current or electric power to be reduced or not, the current or electric power to be input to the power source  10  from the external unit such as the charging unit  200 . In this way, the load applied to the power source  10  can be reduced in a case where the environment around the power source  10  is poor. Note that the reduction in the amount of current by the first controller  50  can be achieved by controlling the switch so that the current flows through a line having a higher electric resistance. Besides, the reduction in the amount of electric power by the first controller  50  can be achieved by temporarily opening the second switch  174  during the charge or temporarily opening the first switch  172  during the discharge.