Vapor provision system and corresponding method

1 . A vapor provision system comprising:

a vaporizer comprising an electrically heated heating element for generating vapor from a vapor precursor material;

a reservoir storing vapor precursor material; and

control circuitry configured to:

(a) supply a first, non-zero level of power to the vaporizer to generate vapor from at least a portion of vapor precursor material;

(b) determine the electrical resistance of the heating element used to generate said vapor;

(c) determine a depletion condition of the vapor precursor material based on monitoring a parameter indicative of a quantity of at least a portion of the vapor precursor material, wherein the monitored parameter is the determined electrical resistance of the heating element, and comparing the monitored parameter to a plurality of thresholds, including a first threshold, wherein each of the thresholds is indicative of a different degree of depletion of the at least a portion of the vapor precursor material; and

(d) subsequent to (c), in response to the control circuitry determining there is depletion based on the comparison between the monitored parameter and the first threshold, (i) begin supplying a second, non-zero level of power to the vaporizer instead of the first, non-zero level of power, the second level of power being lower than the first level of power, and (ii) begin comparing the monitored parameter to a second threshold;

(e) subsequent to (d), in response to the control circuitry determining there is depletion based on the comparison between the monitored parameter and the second threshold, (i) begin supplying a third non-zero level of power to the vaporizer instead of the second, non-zero level of power, the third level of power being lower than the second level of power, and wherein each of the thresholds corresponds to one of a plurality of different non-zero power levels configured to be output by the control circuitry.

2 . The vapor provision system of claim 1 , wherein the second level of power is less than 70% of the first level of power.

3 . The vapor provision system of claim 1 , wherein the second level of power is set such that the vapor provision system can continue to generate vapor even after the control circuitry determines there is depletion of the at least a portion of the vapor precursor material.

4 . The vapor provision system of claim 1 , wherein the control circuitry is configured to supply power to the vaporizer using pulse width modulation, and wherein the first and second power levels are an average power over one duty cycle of the pulse width modulation.

5 . The vapor provision system of claim 1 , wherein the system further comprises an indicator, and wherein the control circuitry is configured to activate the indicator when the control circuitry determines that there is depletion based on the comparison between the monitored parameter and the first threshold.

6 . The vapor provision system of claim 1 , wherein the system further comprises a vapor precursor transport element configured to transport the vapor precursor material from the reservoir to the vaporizer.

7 . The vapor provision system of claim 6 , wherein the depletion condition of the vapor precursor material is an indication of the quantity of vapor precursor material within the vapor precursor transport element.

8 . The vapor provision system of claim 1 , wherein the control circuitry is configured to repeatedly compare the monitored parameter to the first threshold.

9 . The vapor provision system of claim 1 , wherein, when the control circuitry supplies the second level of power to the vaporizer, the control circuitry is configured to compare the monitored parameter to the first threshold and supply the first level of power when the control circuitry determines there is no longer depletion based on the comparison between the monitored parameter and the first threshold.

10 . The vapor provision system of claim 1 , wherein the depletion condition of the vapor precursor material is an indication of the quantity of vapor precursor material within the reservoir.

11 . The vapor provision system of claim 1 , wherein the second level of power is less than 50% of the first level of power.

12 . The vapor provision system of claim 1 , wherein the second level of power is less than 30% of the first level of power.

13 . A control circuitry, for use in a vapor provision system for generating a vapor from a vapor precursor material, the vapor provision system comprising a vaporizer comprising an electrically heated heating element for generating vapor from a precursor material, wherein the control circuitry is configured to:

supply a first, non-zero level of power to the vaporizer to generate vapor from at least a portion of vapor precursor material;

determine the electrical resistance of the heating element used to generate said vapor;

determine a depletion condition of the vapor precursor material based on monitoring a parameter indicative of a quantity of at least a portion of the vapor precursor material, wherein the monitored parameter is the determined electrical resistance of the heating element;

compare the monitored parameter to a plurality of thresholds, including a first threshold, wherein each of the thresholds is indicative of a degree of depletion of the at least a portion of the vapor precursor material; and

in response to the circuitry determining there is depletion based on the comparison between the monitored parameter and the first threshold, begin supplying a second, non-zero level of power to the vaporizer instead of the first, non-zero level of power, the second level of power being lower than the first level of power, and wherein once the control circuitry determines there is depletion on the basis of the first threshold, the control circuitry is configured to compare the monitored parameter to a second threshold;

in response to the circuitry determining there is a depletion based on the comparison between the monitored parameter and the second threshold, begin supplying a third non-zero level of power to the vaporizer, the third level of power being lower than the second level of power, wherein each of the thresholds corresponds to one of a plurality of different non-zero power levels configured to be output by the control circuitry.

14 . The control circuitry of claim 13 , wherein the depletion condition of the vapor precursor material is an indication of the quantity of vapor precursor material within the reservoir.

15 . A method of operating control circuitry for a vapor provision system comprising a vaporizer comprising an electrically heated heating element for generating vapor from a vapor precursor material and a reservoir storing vapor precursor material, wherein the method comprises:

(a) supplying, via the control circuitry, a first, non-zero level of power to the vaporizer to generate vapor from at least a portion of vapor precursor material;

(b) determine the electrical resistance of the heating element used to generate said vapor;

(c) determining, via the control circuitry, a depletion condition of the vapor precursor material based on monitoring a parameter indicative of a quantity of at least a portion of the vapor precursor material, wherein the monitored parameter is the determined electrical resistance of the heating element, and comparing the monitored parameter to a plurality of thresholds, including a first threshold, wherein each of the thresholds is indicative of a respective degree of depletion of the at least a portion of the vapor precursor material; and

(d) subsequent to (c), in response to the circuitry determining there is depletion based on the comparison between the monitored parameter and the first threshold, (i) supplying, via the control circuitry, a second, non-zero level of power to the vaporizer, the second level of power being lower than the first level of power instead of the first, non-zero level of power, and (ii) wherein once the control circuitry determines there is depletion on the basis of the first threshold, the control circuitry is configured to begin comparing the monitored parameter to a second threshold; and

(e) subsequent to (d), in response to the control circuitry determining there is depletion based on the comparison between the monitored parameter and the second threshold, (i) begin supplying a third non-zero level of power to the vaporizer, the third level of power being lower than the second level of power, wherein each of the thresholds corresponds to one of a plurality of different non-zero power levels configured to be output by the control circuitry.

16 . The method of claim 15 , wherein the depletion condition of the vapor precursor material is an indication of the quantity of vapor precursor material within the reservoir.