Aerosol-forming article comprising magnetic particles
An aerosol-forming article for use in an electrically heated aerosol-generating device is provided, the aerosol-forming article including a mouthpiece, an aerosol-forming substrate, and a plurality of magnetic particles including a magnetic material having a Curie temperature of between 60 degrees Celsius and 200 degrees Celsius. An electrically heated aerosol-generating device for receiving the aerosol-forming article is also provided, the device including a heater element configured to heat the aerosol-forming article, an inductor, and a controller configured to measure an inductance of the inductor and to control a supply of electrical current to the heater element in response to the measured inductance.
1. An electrically heated aerosol-generating device configured to receive an aerosol-forming article, the device comprising:
a heater element configured to heat the aerosol-forming article;
an inductor; and
a controller configured to repeatedly measure an inductance of the inductor and a temperature of the heater element, the controller being further configured to vary a supply of electrical current to the heater element in response to the measured inductance to provide a predetermined heating profile.
2. The electrically heated aerosol-generating device according to claim 1 , wherein both the heater element and the inductor are formed by a conductive coil.
3. The electrically heated aerosol-generating device according to claim 2 , wherein the controller is further configured to:
pulse the supply of electrical current through the conductive coil to heat the aerosol-forming article, and
measure an inductance of the conductive coil between current pulses.
4. An electrically heated aerosol-generating system, comprising an electrically heated aerosol-generating device in combination with an aerosol-forming article,
the electrically heated aerosol-generating device comprising:
a heater element configured to heat the aerosol-forming article,
an inductor, and
a controller configured to repeatedly measure an inductance of the inductor and a temperature of the heater element, the controller being further configured to vary a supply of electrical current to the heater element in response to the measured inductance to provide a predetermined heating profile;
the aerosol-forming article comprising:
a mouthpiece,
an aerosol-forming substrate, and
a plurality of magnetic particles comprising a magnetic material having a Curie temperature of between about 60 degrees Celsius and about 200 degrees Celsius.
5. A method of operating an electrically heated aerosol-generating system comprising an aerosol-forming article comprising a plurality of magnetic particles, a heater element configured to heat the aerosol-forming article, an inductor, and a controller configured to measure an inductance of the inductor and to control a supply of electrical current to the heater element, the method comprising:
measuring the inductance of the inductor;
comparing the measured inductance with one or more predetermined values of inductance;
controlling the supply of electrical current to the heater element based on the comparison of the measured inductance with the one or more predetermined values of inductance, by activating the supply of current to the heater element to heat the aerosol-forming article to a temperature above a Curie temperature of the plurality of magnetic particles;
repeatedly measuring the inductance of the inductor and the temperature of the heater element during the heating of the aerosol-forming article;
determining when a decrease in the measured inductance occurs during the heating of the aerosol-forming article, the decrease in the inductance being indicative of the plurality of magnetic particles being heated to the Curie temperature; and
varying the electrical current supplied to the heater element to provide a predetermined heating profile,
wherein the predetermined heating profile is selected based on at least one of a time at which the decrease in measured inductance occurs and a heater element temperature at which the decrease in measured inductance occurs.
6. The method according to claim 5 ,
wherein the controlling the supply of electrical current to the heater element further comprises supplying no current to the heater element if the measured inductance does not match any of the one or more predetermined values of inductance, and
wherein each of the one or more predetermined values of inductance corresponds to a type of aerosol-forming article.
7. The method according to claim 5 ,
wherein the one or more predetermined values of inductance comprises a plurality of predetermined values of inductance,
wherein the controlling the supply of electrical current to the heater element further comprises varying the electrical current supplied to the heater element to provide a predetermined heating profile, and
wherein the predetermined heating profile is selected based on which of the plurality of predetermined values of inductance matches the measured inductance.
8. The method according to claim 5 ,
wherein the electrically heated aerosol-generating system further comprises a conductive coil that forms both the heater element and the inductor,
wherein the activating the supply of electrical current to the heater element to heat the aerosol-forming substrate further comprises pulsing the supply of electrical current through the conductive coil, and
wherein the repeatedly measuring the inductance of the inductor further comprises measuring the inductance of the conductive coil between current pulses.