METHODS FOR DETERMINING HEATER CONDITIONS IN AN AEROSOL-GENERATING SYSTEM

Claims

1. An electrically powered aerosol generating system comprising: a heating element for heating an aerosol-forming substrate near the heating element; a power source for supplying power to the heating element; and an electrical circuit connected to the heating element and the power source and containing a memory, wherein the electrical circuit is configured to: regulating the power supply to the heating element during the heating cycle period in response to user input; determining the first derivative of the electrical resistance of the heating element with respect to time; determining the presence of an unfavorable condition if said first derivative of the electrical resistance exceeds a threshold value stored in memory during a heating cycle period at or after a specified point in time during a heating cycle period; and controlling the supply of power to the heating element based on whether an unfavorable condition exists on the heating element, or providing an indication based on whether an unfavorable condition exists on the heating element.

2. An electrical aerosol generating system according to claim 1, wherein the electrical circuit is configured to calculate the second derivative of the electrical resistance of the heating element with respect to time, and said specified time is the time until said second derivative becomes greater than or equal to a threshold value of the second derivative.

3. An electrical aerosol generating system according to claim 2, wherein the threshold value of the second derivative is zero.

4. The electrical aerosol generating system of claim 1, wherein the predetermined time is a fixed period of time after the start of the heating cycle period, wherein said fixed period of time is stored in memory.

5. An electrical aerosol generating system according to any one of the preceding claims, further comprising a mouthpiece on which a user has the ability to puff to draw an aerosol from the system, wherein the electrical circuit comprises a puff detector for detecting the moments when the user takes a puff on the system as user inputs, and wherein said electrical circuit is configured to supply power from a power source to a heating element upon detection of a puff by said puff detector.

6. An electrically powered aerosol generating system according to any one of the preceding claims, wherein the electrical circuit is configured to detect the presence of an unfavorable condition during each heating cycle.

7. An electrical aerosol generating system according to any one of the preceding claims, comprising a device and a removable cartridge, wherein the power source and electrical circuit are in the device and the heating element is in the removable cartridge, and wherein the cartridge contains a liquid aerosol-forming substrate.

8. An electrical aerosol generating system comprising: a heating element for heating an aerosol-forming substrate near the heating element; a power source for supplying power to the heating element; and an electrical circuit connected to the heating element and the power source, wherein the electrical circuit is configured to: regulating the power supply to the heating element during the heating cycle period in response to user input; determination of the second derivative of electrical resistance with respect to time; and determining the unfavorable condition if the second derivative is greater than or equal to the threshold value of the second derivative; and controlling the supply of power to the heating element based on whether an unfavorable condition exists on the heating element, or providing an indication based on whether an unfavorable condition exists on the heating element.

9. An electrical aerosol generating system according to claim 8, wherein the threshold value of the second derivative is zero.

10. An electrical aerosol generating system according to any one of the preceding claims, wherein the electrical circuit is configured to measure the flow rate of air passing through the system, and wherein said electrical circuit is configured to adjust the results of the electrical resistance measurement or one or more stored threshold values ​​based on the measured air flow rate.

11. A method for controlling the supply of power to a heating element in an electric aerosol generating system, comprising the steps of: regulate the supply of power to the heating element during a heating cycle period in response to a user input; determine the first derivative of the electrical resistance of the heating element with respect to time; determining that an unfavorable condition exists if the first derivative of the electrical resistance exceeds a threshold value stored in memory during a period of the heating cycle at or after a given point in time during the period of the heating cycle; and control the supply of power to the heating element based on whether an unfavorable condition exists on the heating element, or provide an indication based on whether an unfavorable condition exists on the heating element.

12. The method of claim 11, further comprising the step of calculating the second derivative of the electrical resistance of the heating element with respect to time, wherein said specified time is the time until said second derivative becomes greater than or equal to a threshold value of the second derivative.

13. The method according to claim 11 or 12, further comprising the steps of: measure the air flow rate passing through the system and adjust the electrical resistance measurement results or one or more stored threshold values ​​based on the measured air flow rate.

14. A method for controlling the supply of power to a heating element in an electric aerosol generating system, comprising the steps of: regulate the power supply to the heating element during a heating cycle period in response to a user input; determine the second derivative of electrical resistance with respect to time; and define an unfavorable condition if the second derivative is greater than or equal to the threshold value of the second derivative; and control the supply of power to the heating element based on whether an unfavorable condition exists on the heating element, or provide an indication based on whether an unfavorable condition exists on the heating element; in this case, the threshold value of the second derivative is equal to zero.

15. A computer program product that is directly loaded into the internal memory of a microprocessor containing program code blocks for performing the method according to any one of claims 11-14, wherein said product is executed in a programmable electrical circuit in an electrical aerosol-generating system that contains a heating element for heating an aerosol-forming substrate and a power source for supplying power to the heating element, and wherein said electrical circuit is connected to said electrical heater and power source and is configured to determine the electrical resistance of the heating element.