# US 2021/0243844 A1 · Aerosol generating system with self-activated electric heater > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243844 A1 - Document ID: US20210243844A1 - Status: Published application - Kind: A1 - Application number: 17/239,855 - Filed: 2021-04-26 - Published: 2021-08-05 - Earliest claimed: 2015-11-17 - Assignees: Altria Client Services LLC - Applicants: Altria Client Services LLC - Inventors: Tony REEVELL - Web page: https://patentgrep.com/patent/US20210243844A1 ## CPC - A24F 40/50: Control or monitoring - A24F 40/46: Shape or structure of electric heating means - A24F 40/53: Monitoring, e.g. fault detection - H05B 1/0244: {Heating of fluids (H05B1/0247 takes precedence)} - H05B 3/04: Waterproof or air-tight seals for heaters - H05B 3/44: heating conductor arranged within rods or tubes of insulating material - A24F 40/10: Devices using liquid inhalable precursors - H05B 2203/014: Heaters using resistive wires or cables not provided for in H05B3/54 - H05B 2203/021: Heaters specially adapted for heating liquids - A24F: SMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES (inhaling appliances for medical purposes, shaped like cigars, cigarettes or pipes A61M15/06) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract An electronic vaping device includes a liquid storage portion, an electric heater and electronic circuitry. The liquid storage portion is configured to store liquid vapor-forming substrate. The electric heater includes at least one heating element, the at least one heating element configured to heat the liquid vapor-forming substrate. The electronic circuitry is configured to self-activate the electric heater for a first time interval during a period of inactivity of the electric heater to determine depletion of the liquid vapor-forming substrate based on a relationship between a power applied to the at least one heating element and a resulting temperature change of the at least one heating element. ## Claims ### Claim 1 An electronic vaping device comprising: a reservoir configured to store pre-vapor formulation; an electric heater configured to heat pre-vapor formulation drawn from the reservoir; and electronic circuitry configured to self-activate the electric heater for a first time interval during an inactivity period after a threshold number of activations of the electric heater, each activation of the electric heater being in response to application of negative pressure to the electronic vaping device, and the inactivity period being a time period during which negative pressure is not applied to the electronic vaping device, and determine at least one characteristic of the electric heater during the first time interval, and determine whether to deactivate the electronic vaping device based on the at least one characteristic of the electric heater. ### Claim 2 (depends on 1) The electronic vaping device according to claim 1, wherein the at least one characteristic of the electric heater is a temperature of the electric heater during the first time interval. ### Claim 3 (depends on 2) The electronic vaping device according to claim 2, further comprising: a temperature sensor configured to measure the temperature of the electric heater. ### Claim 4 (depends on 2) The electronic vaping device according to claim 2, wherein the electronic circuitry is configured to determine the temperature of the electric heater based on an electrical resistance of the electric heater. ### Claim 5 (depends on 1) The electronic vaping device according to claim 1, wherein the electronic circuitry is configured to self-activate the electric heater in response to the threshold number of activations of the electric heater and a temperature of the electric heater falling below a temperature threshold. ### Claim 6 (depends on 1) The electronic vaping device according to claim 1, wherein the electronic circuitry is configured to self-activate the electric heater in response to the threshold number of activations of the electric heater and a threshold length of inactivity after a last application of negative pressure to the electronic vaping device. ### Claim 7 (depends on 1) The electronic vaping device according to claim 1, wherein the electronic circuitry is configured to estimate an amount of pre-vapor formulation in the reservoir based on the at least one characteristic of the electric heater, and determine whether to deactivate the electronic vaping device based on the amount of pre-vapor formulation in the reservoir. ### Claim 8 (depends on 7) The electronic vaping device according to claim 7, wherein the electronic circuitry is configured to adjust a frequency of self-activations of the electric heater based on the amount of pre-vapor formulation in the reservoir. ### Claim 9 (depends on 7) The electronic vaping device according to claim 7, wherein the electronic circuitry is configured to adjust a frequency of self-activations of the electric heater as the amount of pre-vapor formulation in the reservoir decreases over time. ### Claim 10 (depends on 1) The electronic vaping device according to claim 1, wherein the electronic circuitry is configured to adjust a frequency of self-activations of the electric heater as an amount of pre-vapor formulation in the reservoir decreases over time. ### Claim 11 An electronic vaping device comprising: a reservoir configured to store pre-vapor formulation; an electric heater configured to heat pre-vapor formulation drawn from the reservoir; and electronic circuitry configured to self-activate the electric heater after a threshold time period during which negative pressure is not applied to the electronic vaping device, and adjust a frequency of self-activations of the electric heater as an amount of pre-vapor formulation in the reservoir decreases over time. ### Claim 12 (depends on 11) The electronic vaping device of claim 11, wherein the electronic circuitry is configured to determine at least one characteristic of the electric heater during a first time interval after expiration of the threshold time period, and estimate the amount of pre-vapor formulation in the reservoir based on the at least one characteristic of the electric heater. ### Claim 13 (depends on 12) The electronic vaping device according to claim 12, wherein the at least one characteristic of the electric heater is a temperature of the electric heater during the first time interval. ### Claim 14 (depends on 13) The electronic vaping device according to claim 13, further comprising: a temperature sensor configured to measure the temperature of the electric heater. ### Claim 15 (depends on 13) The electronic vaping device according to claim 13, wherein the electronic circuitry is configured to determine the temperature of the electric heater based on an electrical resistance of the electric heater. ### Claim 16 (depends on 11) The electronic vaping device according to claim 11, wherein the electronic circuitry is configured to self-activate the electric heater in response to an occurrence of at least one self-activation condition. ### Claim 17 (depends on 16) The electronic vaping device according to claim 16, wherein the at least one self-activation condition includes expiration of the threshold time period. ### Claim 18 (depends on 16) The electronic vaping device according to claim 16, wherein the at least one self-activation condition includes a threshold number of activations of the electric heater in response to application of negative pressure to the electronic vaping device. ### Claim 19 (depends on 16) The electronic vaping device according to claim 16, wherein the at least one self-activation condition includes a temperature of the electric heater falling below a threshold temperature. ### Claim 20 (depends on 11) The electronic vaping device according to claim 11, wherein the electronic circuitry is configured to determine at least one characteristic of the electric heater during a first time interval after expiration of the threshold time period, estimate an amount of pre-vapor formulation in the reservoir based on the at least one characteristic of the electric heater, and determine whether to deactivate the electronic vaping device based on the amount of pre-vapor formulation in the reservoir. ### Claim 21 (depends on 11) The electronic vaping device according to claim 11, wherein the electronic circuitry is configured to determine at least one characteristic of the electric heater during a first time interval after expiration of the threshold time period, estimate an amount of pre-vapor formulation in the reservoir based on the at least one characteristic of the electric heater, and adjust a frequency of self-activations based on the amount of pre-vapor formulation in the reservoir.