Hot wire anemometer air flow measurement, puff detection and ambient temperature tracking

Patent metadata

Field	Value
Publication number	US-12329208-B2
Application number	US-202418418738-A
Country	US
Kind code	B2
Filing date	Jan 22, 2024
Priority date	Jan 22, 2020
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

A method of controlling a hot wire anemometer (HWA) of a non-nicotine e-vaping device includes controlling, by a first PID controller, a level of power applied by the non-nicotine e-vaping device to the HWA based on a temperature of a heated element of the HWA and a temperature setpoint; generating a puff detection signal indicating whether or not a puff is currently occurring with respect to the non-nicotine e-vaping device; and while the puff detection signal indicates that a puff is not currently occurring with respect to the non-nicotine e-vaping device, detecting, by a second PID controller, a change in an ambient temperature of the HWA, and controlling, by the second PID controller, the temperature setpoint such that the temperature setpoint changes in response to the detected change in the ambient temperature of the HWA.

First claim

The invention claimed is:

1. A non-nicotine e-vaping device, comprising:
a hot wire anemometer (HWA);
a first proportional-integral-derivative (PID) controller configured to control a level of power applied by the non-nicotine e-vaping device to the HWA based on a temperature of a heated element of the HWA and a temperature setpoint;
a puff detection signal generator configured to generate a puff detection signal indicating whether or not a puff is currently occurring with respect to the non-nicotine e-vaping device, the puff detection signal having a first logical value when the puff is occurring and a second logical value when the puff is not occurring, and the temperature setpoint being fixed while the puff detection signal has the first logical value indicating that the puff is currently occurring with respect to the non-nicotine e-vaping device; and
a second PID controller configured such that, while the puff detection signal has the second logical value indicating that the puff is not currently occurring with respect to the non-nicotine e-vaping device, the second PID controller
detects a change in an ambient temperature of the HWA, and
controls the temperature setpoint such that the temperature setpoint is adjusted in response to the detected change in the ambient temperature of the HWA.

2. The non-nicotine e-vaping device of claim 1 , wherein the first PID controller is configured to control the level of power applied by the non-nicotine e-vaping device to the HWA by generating a drive signal setting value.

3. The non-nicotine e-vaping device of claim 2 , wherein the level of power applied by the non-nicotine e-vaping device to the HWA is based on the drive signal setting value.

4. The non-nicotine e-vaping device of claim 3 , further comprising:
a drive signal generator configured to,
generate a pulse width modulated (PWM) drive signal based on the drive signal setting value, and
apply the level of power to the HWA by applying the PWM drive signal to the HWA.

5. The non-nicotine e-vaping device of claim 4 , wherein the drive signal generator is configured to control a duty cycle of the PWM drive signal based on the drive signal setting value.

6. The non-nicotine e-vaping device of claim 2 , wherein the second PID controller is further configured to determine a flow rate of air flowing around the HWA based on the drive signal setting value, while the puff detection signal indicates that a puff is currently occurring with respect to the non-nicotine e-vaping device.

7. The non-nicotine e-vaping device of claim 2 , wherein the puff detection signal generator is configured to,
determine a gradient of the drive signal setting value, and
generate the puff detection signal based on the determined gradient of the drive signal setting value.

8. The non-nicotine e-vaping device of claim 2 , wherein the first PID controller is configured to generate the drive signal setting value based on a difference between the temperature of the heated element of the HWA and the temperature setpoint.

9. The non-nicotine e-vaping device of claim 8 , wherein the second PID controller is configured to detect the change in the ambient temperature of the HWA based on a difference between the drive signal setting value and a drive signal setting value setpoint.

10. The non-nicotine e-vaping device of claim 2 , wherein the second PID controller is configured to detect the change in the ambient temperature of the HWA based on a difference between the drive signal setting value and a drive signal setting value setpoint.

11. The non-nicotine e-vaping device of claim 10 , wherein the second PID controller is configured to control the temperature setpoint by,
increasing the temperature setpoint in response to detecting an increase in the ambient temperature of the HWA, and
decreasing the temperature setpoint in response to detecting a decrease in the ambient temperature of the HWA.

12. The non-nicotine e-vaping device of claim 1 , further comprising:
a non-nicotine pre-vapor formulation storage portion for storing a non-nicotine pre-vapor formulation; and
a heater configured to generate a non-nicotine vapor by heating the non-nicotine pre-vapor formulation.

13. The non-nicotine e-vaping device of claim 12 , wherein the non-nicotine pre-vapor formulation storage portion includes a wick configured to transfer the non-nicotine pre-vapor formulation to the heater.

14. The non-nicotine e-vaping device of claim 13 , wherein the heater comprises a folded heating element configured to grip the wick.

15. The non-nicotine e-vaping device of claim 14 , wherein the folded heating element comprises at least one prong configured to protrude into the wick.

16. The non-nicotine e-vaping device of claim 12 , wherein the non-nicotine pre-vapor formulation storage portion includes an inlet and an outlet, the inlet and the outlet configured to define a flow path through the non-nicotine pre-vapor formulation storage portion.

17. The non-nicotine e-vaping device of claim 1 , wherein the heated element of the HWA is an etched serpentine element comprising a serpentine wire suspended between a first support and a second support.

Assignees

• Altria Client Services Llc

Inventors

• Parrott Adam
• Gallagher Niall
• Lau Raymond W
• Hawes Eric
• Newcomb Ryan
• Bache Terry
• Sundar Rangaraj S
• Keen Jarrett

Classifications

• G01P5/02

  by measuring forces exerted by the fluid on solid bodies, e.g. anemometer · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• A61M2205/3368

  Temperature · CPC title

• A61M2205/3334

  Measuring or controlling the flow rate · CPC title

• A24F40/57

  Temperature control · CPC title