Vaporization device systems and methods
Vaporization devices, components, and methods of operating them are provided. In some implementations, an apparatus includes a microcontroller, a battery, and electrical circuitry comprising a reference resistor, a first switch, a second switch, and a voltage divider. The microcontroller is configured to operate the first switch to interrupt a flow of current supplied from the power source through a resistive heating element, and to operate the second switch to add the reference resistor in series with the resistive heating element. The microcontroller is further configured to determine a resistance of the resistive heating element based on a voltage measured by the voltage divider when the reference resistor is in series with the resistive heating element, and to control an amount of power supplied to the resistive heating element based on the determined resistance by adjusting the flow of current supplied to the resistive heating element.
1. An apparatus comprising:
a fluid storage compartment configured to hold a vaporizable material;
a resistive heating element configured to heat to cause vaporization of the vaporizable material; and
a device body comprising a power source, electrical circuitry, and a microcontroller, wherein the electrical circuitry includes a reference resistor, a first switch, a second switch, and a voltage divider, and wherein the microcontroller is configured to perform operations comprising:
operating the first switch to interrupt a flow of current supplied from the power source through the resistive heating element;
operating the second switch, in conjunction with operating the first switch, to add the reference resistor in series with the resistive heating element;
determining a resistance of the resistive heating element based on a voltage measured by the voltage divider when the reference resistor is in series with the resistive heating element; and
controlling an amount of power supplied to the resistive heating element based on the determined resistance by adjusting the flow of current supplied to the resistive heating element.
2. The apparatus of claim 1 , wherein the microcontroller is further configured to perform operations comprising:
determining that the determined resistance exceeds a threshold resistance indicative of the resistive heating element being dry; and
interrupting the flow of current supplied from the power source in response to determining that the determined resistance exceeds the threshold resistance.
3. The apparatus of claim 1 , further comprising:
a pressure sensor configured to detect when a user is puffing, wherein the electrical circuitry is configured to supply, in response to detecting the user puffing, the flow of current from the power source through the resistive heating element that is configured to cause vaporization of the vaporizable material.
4. The apparatus of claim 1 , wherein the microcontroller comprises a proportional-integral-derivative controller, and wherein the microcontroller is further configured to monitor whether the determined resistance exceeds a resistance value indicating that the resistive heating element has reached a setpoint temperature value.
5. The apparatus of claim 4 , wherein the microcontroller is further configured to perform operations comprising:
monitoring the amount of power supplied to the resistive heating element that is required to maintain the resistive heating element at the setpoint temperature value; and
interrupting the flow of current supplied from the power source in response to detecting that the amount of power supplied to the resistive heating element is below a threshold power level.
6. The apparatus of claim 4 , wherein the microcontroller is further configured to perform operations comprising:
preventing, during a time period in which the determined resistance exceeds the resistance value, the flow of current from the power source to the resistive heating element.
7. The apparatus of claim 4 , wherein the setpoint temperature value is between 200° C. and 400° C.
8. The apparatus of claim 1 , wherein controlling the amount of power supplied to the resistive heating element based on the determined resistance by adjusting the flow of current supplied to the resistive heating element uses pulse width modulation control.
9. The apparatus of claim 1 , wherein operating the first switch to interrupt the flow of current through the resistive heating element occurs at fixed intervals.
10. The apparatus of claim 1 , wherein operating the second switch to add the reference resistor in series with the resistive heating element occurs when the first switch interrupts the flow of current through the resistive heating element to provide stable measurements of the determined resistance.
11. An apparatus comprising:
electrical circuitry comprising a reference resistor, a first switch, a second switch, and a voltage divider, wherein the electrical circuitry is configured to electrically couple to a power source, and wherein the electrical circuitry is further configured to power a resistive heating element via the power source to cause vaporization of a vaporizable material; and
a microcontroller configured to perform operations comprising:
operating the first switch to interrupt a flow of current supplied from the power source through the resistive heating element;
operating the second switch, in conjunction with operating the first switch, to add the reference resistor in series with the resistive heating element;
determining a resistance of the resistive heating element based on a voltage measured by the voltage divider when the reference resistor is in series with the resistive heating element; and
controlling an amount of power supplied to the resistive heating element based on the determined resistance by adjusting the flow of current supplied to the resistive heating element.
12. The apparatus of claim 11 , wherein the microcontroller is further configured to perform operations comprising:
determining that the determined resistance exceeds a threshold resistance indicative of the resistive heating element being dry; and
interrupting the flow of current supplied from the power source in response to determining that the determined resistance exceeds the threshold resistance.
13. The apparatus of claim 11 , further comprising:
a pressure sensor configured to detect when a user is puffing, wherein the electrical circuitry is configured to supply, in response to detecting the user puffing, the flow of current from the power source through the resistive heating element that is configured to cause vaporization of the vaporizable material.
14. The apparatus of claim 11 , wherein the microcontroller comprises a proportional-integral-derivative controller, and wherein the microcontroller is further configured to monitor whether the determined resistance exceeds a resistance value indicating that the resistive heating element has reached a setpoint temperature value.
15. The apparatus of claim 14 , wherein the microcontroller is further configured to perform operations comprising:
monitoring the amount of power supplied to the resistive heating element that is required to maintain the resistive heating element at the setpoint temperature value; and
interrupting the flow of current supplied from the power source in response to detecting that the amount of power supplied to the resistive heating element is below a threshold power level.
16. The apparatus of claim 14 , wherein the microcontroller is further configured to perform operations comprising:
preventing, during a time period in which the determined resistance exceeds the resistance value, the flow of current from the power source to the resistive heating element.
17. The apparatus of claim 14 , wherein the setpoint temperature value is between 200° C. and 400° C.
18. The apparatus of claim 11 , wherein controlling the amount of power supplied to the resistive heating element based on the determined resistance by adjusting the flow of current supplied to the resistive heating element uses pulse width modulation control.
19. The apparatus of claim 11 , wherein operating the first switch to interrupt the flow of current through the resistive heating element occurs at fixed intervals.
20. The apparatus of claim 11 , wherein operating the second switch to add the reference resistor in series with the resistive heating element occurs when the first switch interrupts the flow of current through the resistive heating element to provide stable measurements of the determined resistance.