Quasi-resonant flyback converter for an induction-based aerosol delivery device

• US 10,806,181 B2
• Filed: 12/08/2017
• Issued: 10/20/2020
• Est. Priority Date: 12/08/2017
• Status: Active Grant

• Current Assignee: RAI STRATEGIC HOLDINGS, INC. (British American Tobacco PLC)
• Original Assignee: RAI STRATEGIC HOLDINGS, INC. (British American Tobacco PLC)
• Inventors: Sur, Rajesh
• Primary Examiner(s): Baker, Lori L
• Application Number:
  US15/836,086
• Publication Number:
  US 20190174823A1
• Time in Patent Office: 1,047 Days
• Field of Search: 219660
• CPC Class Codes: A24F 40/10 Devices using liquid inhalable precursors
• CPC Class Codes: A24F 40/20 Devices using solid inhalable precursors
• CPC Class Codes: A24F 40/46 Shape or structure of electric heating means
• CPC Class Codes: A24F 40/465 specially adapted for induction heating
• CPC Class Codes: A24F 40/50 Control or monitoring
• CPC Class Codes: A24F 40/57 Temperature control
• CPC Class Codes: H02M 3/3353 having at least two simultaneously operating switches on the input side, e.g. "double forward" or "double (switched) flyback" converter
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An aerosol delivery device includes an aerosol precursor composition and a quasi-resonant flyback converter configured to cause components of the aerosol precursor composition to vaporize to produce an aerosol. The quasi-resonant flyback converter includes a transformer including an induction transmitter and an induction receiver, a capacitor that with the induction transmitter forms a tank circuit. The quasi-resonant flyback converter also includes a transistor that is switchable in cycles to cause the induction transmitter to generate an oscillating magnetic field and induce an alternating voltage in the induction receiver when exposed to the oscillating magnetic field, the alternating voltage causing the induction receiver to generate heat and thereby vaporize components of the aerosol precursor composition.

Claims

1. An aerosol delivery device comprising an aerosol precursor composition and a quasi-resonant flyback converter configured to cause components of the aerosol precursor composition to vaporize to produce an aerosol, the quasi-resonant flyback converter comprising:

a transformer including an induction transmitter and an induction receiver;

a capacitor that with the induction transmitter forms a tank circuit; and

a transistor that is switchable in cycles to cause the induction transmitter to generate an oscillating magnetic field and induce an alternating voltage in the induction receiver when exposed to the oscillating magnetic field, the alternating voltage causing the induction receiver to generate heat and thereby vaporize components of the aerosol precursor composition,

wherein each of the cycles includes an on-interval in which the transistor is switched on to enable current through the induction transmitter that causes the induction transmitter to generate a magnetic field in which the induction transmitter stores energy, and an off-interval in which the transistor is switched off to disable current through the induction transmitter that causes a collapse of the magnetic field, and the collapse of the magnetic field causes a transfer of the energy from the induction transmitter to the induction receiver, and charges the capacitor and thereby causes a voltage waveform at a drain of the transistor, and

wherein the quasi-resonant flyback converter further comprises a comparator with two input terminals coupled to either side of the capacitor between the capacitor and the drain of the transistor, the comparator being configured to detect a trough in the voltage waveform during the off-interval in which the transistor is switched off, and in response produce an output to cause the transistor to switch on for the on-interval.

2. The aerosol delivery device of claim 1, wherein the aerosol precursor composition includes a solid tobacco material, a semi-solid tobacco material or a liquid aerosol precursor composition.

3. The aerosol delivery device of claim 1, wherein the quasi-resonant flyback converter further comprises first and second voltage dividers whose inputs are coupled to either side of the capacitor, the two input terminals of the comparator being coupled to outputs of respective ones of the first and second voltage dividers and thereby coupled to either side of the capacitor.

4. The aerosol delivery device of claim 1, wherein the comparator is implemented by a coprocessor that is also configured to implement a pulse-width modulation (PWM) controller that is configured to receive the output from the comparator, and in response drive the transistor to switch on for the on-interval.

5. The aerosol delivery device of claim 4, wherein the coprocessor is further configured to implement a glitch filter coupled to and between the comparator and PWM controller, the glitch filter being configured to receive and remove glitch pulses from the output of the comparator and thereby produce a filtered output, and the PWM controller is configured to receive the filtered output, and in response drive the transistor to switch on for the on-interval.

6. The aerosol delivery device of claim 4, wherein the coprocessor is embodied as a programmable system-on-chip (PSoC).

7. The aerosol delivery device of claim 1, wherein the comparator is implemented by a coprocessor that is also configured to implement a glitch filter that is configured to receive and remove glitch pulses from the output of the comparator.

8. The aerosol delivery device of claim 7, wherein the coprocessor is embodied as a programmable system-on-chip (PSoC).

9. The aerosol delivery device of claim 1, wherein the comparator is implemented by a coprocessor that is embodied as a programmable system-on-chip (PSoC), and that is also configured to implement a pulse-width modulation (PWM) controller and a glitch filter coupled to and between the comparator and PWM controller, and

wherein the glitch filter is configured to receive and remove glitch pulses from the output of the comparator and thereby produce a filtered output, and the PWM controller is configured to receive the filtered output, and in response drive the transistor to switch on for the on-interval.

10. The aerosol delivery device of claim 1, wherein the comparator is implemented by an individual electronic component or a circuit constructed of discrete electronic components.

11. The aerosol delivery device of claim 1, wherein the transistor has a drain-to-source on-state resistance (R_DS(on)) that is inversely proportional to a switching time of the transistor, and that is directly proportional to a time in which the alternating voltage is induced in the induction receiver and thereby the heat is generated.

12. The aerosol delivery device of claim 1 further comprising a power source connected to an electrical load that includes the transformer, the power source being configured to supply a current to the load, an amount of the heat the induction receiver is caused to generate being directly proportional to an intensity of the current supplied by the power source.

13. The aerosol delivery device of claim 12, wherein the power source includes a rechargeable primary battery and a rechargeable secondary battery in a parallel combination.

14. The aerosol delivery device of claim 1, wherein the induction receiver includes a coil, an amount of the heat the induction receiver is caused to generate being directly proportional to a length of the coil.

15. A control body for an aerosol delivery device, the control body comprising:

a housing having an opening defined in one end thereof, the opening configured to receive an aerosol source member that defines a heated end and a mouth end and includes an aerosol precursor composition; and

within the housing,

a quasi-resonant flyback converter comprising;

a transformer including an induction transmitter and an induction receiver;

a capacitor that with the induction transmitter forms a tank circuit; and

a transistor that is switchable in cycles to cause the induction transmitter to generate an oscillating magnetic field and induce an alternating voltage in the induction receiver when exposed to the oscillating magnetic field, the alternating voltage causing the induction receiver to generate heat and, when the aerosol source member is inserted into the housing, vaporize components of the aerosol precursor composition to produce an aerosol,

wherein each of the cycles includes an on-interval in which the transistor is switched on to enable current through the induction transmitter that causes the induction transmitter to generate a magnetic field in which the induction transmitter stores energy, and an off-interval in which the transistor is switched off to disable current through the induction transmitter that causes a collapse of the magnetic field, and the collapse of the magnetic field causes a transfer of the energy from the induction transmitter to the induction receiver, and charges the capacitor and thereby causes a voltage waveform at a drain of the transistor, and

wherein the quasi-resonant flyback converter further comprises a comparator with two input terminals coupled to either side of the capacitor between the capacitor and the drain of the transistor, the comparator being configured to detect a trough in the voltage waveform during the off-interval in which the transistor is switched off, and in response produce an output to cause the transistor to switch on for the on-interval.

16. The control body of claim 15, wherein the quasi-resonant flyback converter further comprises first and second voltage dividers whose inputs are coupled to either side of the capacitor, the two input terminals of the comparator being coupled to outputs of respective ones of the first and second voltage dividers and thereby coupled to either side of the capacitor.

17. The control body of claim 15, wherein the comparator is implemented by a coprocessor that is also configured to implement a pulse-width modulation (PWM) controller that is configured to receive the output from the comparator, and in response drive the transistor to switch on for the on-interval.

18. The control body of claim 15, wherein the comparator is implemented by a coprocessor that is also configured to implement a glitch filter that is configured to receive and remove glitch pulses from the output of the comparator.

19. The control body of claim 15, wherein the comparator is implemented by a coprocessor that is embodied as a programmable system-on-chip (PSoC), and that is also configured to implement a pulse-width modulation (PWM) controller and a glitch filter coupled to and between the comparator and PWM controller, and

wherein the glitch filter is configured to receive and remove glitch pulses from the output of the comparator and thereby produce a filtered output, and the PWM controller is configured to receive the filtered output, and in response drive the transistor to switch on for the on-interval.

20. The control body of claim 15, wherein the comparator is implemented by an individual electronic component or a circuit constructed of discrete electronic components.

21. A control body for an aerosol delivery device, the control body comprising:

a housing coupled or coupleable with a cartridge that is equipped with an induction receiver and contains an aerosol precursor composition; and

within the housing,

a quasi-resonant flyback converter comprising;

an induction transmitter that with the induction receiver forms a transformer;

a capacitor that with the induction transmitter forms a tank circuit; and

a transistor that is switchable in cycles to cause the induction transmitter to generate an oscillating magnetic field and induce an alternating voltage in the induction receiver when the housing is coupled with the cartridge and the induction receiver is exposed to the oscillating magnetic field, the alternating voltage causing the induction receiver to generate heat and thereby vaporize components of the aerosol precursor composition to produce an aerosol,

wherein each of the cycles includes an on-interval in which the transistor is switched on to enable current through the induction transmitter that causes the induction transmitter to generate a magnetic field in which the induction transmitter stores energy, and an off-interval in which the transistor is switched off to disable current through the induction transmitter that causes a collapse of the magnetic field, and the collapse of the magnetic field causes a transfer of the energy from the induction transmitter to the induction receiver, and charges the capacitor and thereby causes a voltage waveform at a drain of the transistor, and

wherein the quasi-resonant flyback converter further comprises a comparator with two input terminals coupled to either side of the capacitor between the capacitor and the drain of the transistor, the comparator being configured to detect a trough in the voltage waveform during the off-interval in which the transistor is switched off, and in response produce an output to cause the transistor to switch on for the on-interval.

22. The control body of claim 21, wherein the quasi-resonant flyback converter further comprises first and second voltage dividers whose inputs are coupled to either side of the capacitor, the two input terminals of the comparator being coupled to outputs of respective ones of the first and second voltage dividers and thereby coupled to either side of the capacitor.

23. The control body of claim 21, wherein the comparator is implemented by a coprocessor that is also configured to implement a pulse-width modulation (PWM) controller that is configured to receive the output from the comparator, and in response drive the transistor to switch on for the on-interval.

24. The control body of claim 21, wherein the comparator is implemented by a coprocessor that is also configured to implement a glitch filter that is configured to receive and remove glitch pulses from the output of the comparator.

25. The control body of claim 21, wherein the comparator is implemented by a coprocessor that is embodied as a programmable system-on-chip (PSoC), and that is also configured to implement a pulse-width modulation (PWM) controller and a glitch filter coupled to and between the comparator and PWM controller, and

wherein the glitch filter is configured to receive and remove glitch pulses from the output of the comparator and thereby produce a filtered output, and the PWM controller is configured to receive the filtered output, and in response drive the transistor to switch on for the on-interval.

26. The control body of claim 21, wherein the comparator is implemented by an individual electronic component or a circuit constructed of discrete electronic components.