Evaporator power system

Abstract

A system includes a converter configured to be electrically coupled to a power source and a heating element of a vaporizer cartomizer. The converter can be further configured to receive a first voltage from the power source and provide a second voltage to the heating element. The converter can be a DC-DC converter. A power monitor configured to be electrically coupled to the heating element measures current through the heating element, measures voltage across the heating element, calculates power and / or resistance, and outputs a control signal to the converter. The converter can be configured to be controlled by the control signal to vary the second voltage to maintain a target power or a target temperature on the heating element. Related apparatuses, systems, techniques, and articles of manufacture are also described.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 748,203, entitled “Powering Vapor Atomizer,” filed October 19, 2018, and to U.S. Provisional Patent Application No. 62 / 915,294, entitled “Powering Vapor Atomizer,” filed October 15, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The topic described in this article involves powering an evaporator atomizer using a DC-DC converter. Background Technology

[0004] Evaporator devices, also known as evaporators, electronic evaporator devices, or e-evaporator devices, are used to deliver aerosols (e.g., gaseous and / or condensed phase materials suspended in still or moving air or some other gaseous carrier) by a user inhaling the aerosol containing one or more active ingredients. For example, electronic nicotine delivery systems (ENDS) include a class of battery-powered evaporator devices that can be used to simulate the experience of smoking without burning tobacco or other substances. Evaporators are increasingly popular for the standard medical use of delivering medications and for the consumption of tobacco, nicotine, and other botanical materials. Evaporator devices can be portable, stand-alone, and / or easy to use.

[0005] When using an evaporator device, the user inhales an aerosol, commonly known as "vapor," which can be generated by a heating element that evaporates an evaporable material (e.g., transforms a liquid or solid at least partially into a gaseous phase). The evaporable material can be a liquid, solution, solid, paste, wax, and / or any other form compatible with a particular evaporator device. The evaporable material used with the evaporator can be housed in a cartridge, which is, for example, a separable part of the evaporator device containing the evaporable material, including an outlet (e.g., a mouthpiece) for the user to inhale the aerosol.

[0006] In order to receive the inhalable aerosol produced by the evaporator device, in some examples, the user can activate the evaporator device by inhalation, by pressing a button, and / or by other methods. As used herein, inhalation refers to a user inhaling in a manner that results in a volume of air being drawn into the evaporator device, thereby producing an inhalable aerosol through the combination of the evaporated evaporable material with the volume of air.

[0007] Methods of a vaporizer device to generate an inhalable aerosol from a vaporizable material involve heating the vaporizable material in a vaporizer atomizer or vaporization chamber (e.g., a heater chamber) to convert the vaporizable material to a gas (or vapor) phase. A vaporizer atomizer or vaporization chamber can refer to a region or volume in a vaporizer device where a heat source (e.g., a conductive, convective, and / or radiative heat source) causes heating of a vaporizable material to generate a mixture of air and the vaporizable material to form a vapor for inhalation of the vaporizable material by a user of the vaporization device.

[0008] A vaporizer atomizer can be used to vaporize a liquid into an aerosol, and can require control of the power and temperature of a heating element (e.g., a resistive wire coil) to produce a stable vapor and prevent degradation of the liquid from exposure to high temperatures. Generally, the two parameters related to heating that can be controlled include the electrical power of the heating element and the temperature of the heating element.

[0009] In a typical vaporizer atomizer, the heater coil can be constructed of a conductor with a positive temperature coefficient of resistance (TCR), such that its resistance increases with an increase in its body temperature. A control loop measures the increase in resistance from ambient to high temperature and adjusts the power to the heater to maintain a target operating temperature for consistent vapor production. Heater power control can be achieved through pulse width modulation (PWM), where the current to the heating element is rapidly turned on and off to control the power dissipated as heat in the heating element.

[0010] While this PWM approach can control the heating element, implementations can not tolerate large variations in heater and cartridge contact resistance, can require interruption of power to measure heater resistance, can result in reduced battery run time, can result in reduced run time at lower temperatures, can result in faster battery aging, can result in limited system integration, can result in limited TCR, and can result in increased number and cost of components to measure heater resistance. SUMMARY

[0011] In certain aspects of the current subject matter, challenges related to powering a vaporizer device can be addressed by including one or more features described herein or reasonably / equivalently methods as would be understood by one of ordinary skill in the art. Aspects of the current subject matter relate to methods and systems for powering a heating element of a vaporizer device.

[0012] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the detailed description that follows, and various modifications will be made within the scope and spirit of the subject matter described herein. In some variations, one or more of the following features can optionally be included in any workable combination.

[0013] In one aspect, a system includes a converter configured to be electrically coupled to a power source and a heating element of a vaporizer cartomizer. The converter can be further configured to receive a first voltage from the power source and provide a second voltage to the heating element. The converter can be a DC-DC converter. A power monitor can be configured to be electrically coupled to the heating element, measure a current through the heating element, measure a voltage across the heating element, calculate a power and / or a resistance, and output a control signal to the converter. The converter can be configured to be controlled by the control signal to vary the second voltage to maintain a target power or a target temperature across the heating element.

[0014] One or more of the following features can be included in any workable combination. For example, the converter can include a boost and / or a buck converter. The converter can include an energy storage device. The energy storage device can include a capacitor in a switched capacitor topology or a charge pump topology. The energy storage device can include an inductor. The power monitor can include an analog circuit forming a closed loop control. The power monitor can include an analog front end circuit configured to measure a current through the heating element and a voltage across the heating element, and a digital converter including circuitry configured to provide the control signal based on the measured current through the heating element and the measured voltage across the heating element. The digital converter can be configured to provide the control signal as a pulse width modulation signal, a digital to analog conversion signal, or an inter-integrated circuit (I2C) format signal. The power monitor can include a 4-wire connection to measure the voltage across the heating element. Alternatively, the power monitor can also include a 3-wire connection to measure the voltage across the heating element. The power monitor can continuously measure the current and the voltage without interrupting the heating element power. A microcontroller and a switch can be included between the converter and the heating element. The switch can be electrically coupled to the microcontroller. The microcontroller can be configured to apply a pulse width modulation signal to a gate of the switch. The converter can be configured to operate at a first power level, and the microcontroller can be configured to determine a second power level based on the measured current through the heating element and the measured voltage across the heating element and modify the pulse width modulation signal to control the switch to modify the second voltage.

[0015] The converter can be configured to provide power to the heating element uninterruptedly during a heating cycle. The power monitor can be configured to determine a change in a contact resistance of a contact between the converter and the heating element based on a change in the measured current. The system can further include a current source configured to be coupled to the heating element, the current source including a current source resistor and a current source switch.

[0016] The system can further include a universal serial bus port including a universal serial bus power rail, the converter configured to output a third voltage to the universal serial bus power rail. The system including the converter can also include a pulse width modulation (PWM) control circuit configured to be electrically coupled to the power source and a heating element of the vaporizer atomizer. The pulse width modulation control circuit is further configured to provide PWM power to the heating element. The power source can be a battery.

[0017] In another aspect, an integrated converter includes a converter, a power monitor, and a charger in one unit. The converter can be configured to be electrically coupled to a power source and a heating element of a vaporizer atomizer. The converter can be further configured to receive a first voltage from the power source and provide a second voltage to the heating element. The converter is a DC-DC converter. The power monitor can be configured to be electrically coupled to the heating element, measure a current through the heating element, measure a voltage across the heating element, calculate a power and / or a resistance, and output a control signal to the converter. The charger can be configured to be electrically coupled to the power source to charge the power source. The converter is configured to be controlled by the control signal to vary the second voltage to maintain a target power or a target temperature on the heating element. The converter and the charger can include a common inductor to power the heating element and charge the power source.

[0018] In another aspect, a method includes measuring a current through a heating element of a vaporizer atomizer; measuring a voltage across the heating element; calculating a power and / or a resistance; and controlling operation of a converter to vary a second voltage to maintain a target power or a target temperature on the heating element. The current can be provided by a converter configured to be electrically coupled to a power source and the heating element. The converter can be further configured to receive a first voltage from the power source and provide a second voltage to the heating element. The conversion is a DC-DC converter.

[0019] One or more of the following features can be included in any workable combination. For example, the converter can include a boost and / or a buck converter; the converter can include an energy storage device. The energy storage device can include a capacitor in a switched capacitor topology or a charge pump topology. The energy storage device can include an inductor. The control signal can be provided to the converter as a pulse width modulation signal, a digital to analog converted signal, or an inter-integrated circuit (I2C) format signal. The pulse width modulation signal can be applied to a gate of a switch coupled between a microcontroller, the converter, and the heating element. The converter can be configured to operate at a first power level, and the microcontroller is configured to determine a second power level based on a measured current through the heating element and a measured voltage across the heating element and modify the pulse width modulation signal to control the switch to modify the second voltage. The converter can be configured to provide power to the heating element uninterruptedly during a heating cycle. A change in contact resistance of a contact between the converter and the heating element can be determined based on a change in the measured current.

[0020] The voltage across the heating element can be measured using a 4-wire connection. Alternatively, the voltage across the heating element can also be measured using a 3-wire connection. The current through the heating element can be measured continuously without interrupting the heating element power. The voltage across the heating element can be measured continuously without interrupting the heating element power. The power source can be a battery.

[0021] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings:

[0023] Figure 1A is a block diagram of a vaporizer device.

[0024] Figure 1B is a schematic view of a vaporizer device and a vaporizer cartridge.

[0025] Figure 1C is an elevation view of an embodiment of a vaporizer device and a vaporizer cartridge;

[0026] Figure 1D is an elevation view of a vaporizer cartridge coupled to a vaporizer device;

[0027] Figure 1E is a perspective view of a vaporizer cartridge;

[0028] Figure 1F is a perspective view of another embodiment of a vaporizer cartridge coupled to a vaporizer device;

[0029] Figure 1G is a system diagram illustrating an example PWM heater control;

[0030] Figure 2 is a system diagram illustrating an example heater power control in accordance with some aspects of the current subject matter;

[0031] Figure 3 is a system diagram illustrating an example heater control in which the converter operates as a current source; Figure 2 is a diagram illustrating operational modes of the example heater control 200 shown in

[0032] Figure 4 is a system diagram illustrating an example heater control in which the converter operates as a current source;

[0033] Figure 5 is a process flow diagram illustrating an example process of operating a heater control in accordance with some aspects of the current subject matter; and

[0034] Figure 6 illustrates an example circuit diagram showing electrical resistance and related parameters in an example electrical power path, and including a power control switch.

[0035] In the practice of the application, like reference numerals indicate like structures, features or elements. Like reference numerals in different figures indicate like elements. DETAILED DESCRIPTION

[0036] Implementations of the current subject matter include methods, devices, articles of manufacture, and systems related to the vaporization of one or more materials for inhalation by a user. Example implementations include methods of powering vaporizer devices and systems that include vaporizer devices. The term “vaporizer device” as used in the following description and claims refers to any standalone device, including devices that comprise two or more separable components (e.g., a vaporizer body that includes a battery and other hardware and a cartridge that includes a vaporizable material), and / or the like. A vaporizer device, which can also be referred to as a vaporizer, electronic vaporizer device, or e-vaporizer device, can be used to deliver an aerosol (e.g., a gas phase and / or condensed phase material suspended in stationary or moving air or some other gas carrier) containing one or more active ingredients by vaporization of the device for inhalation by a user of the aerosol. A “vaporizer system” as used herein can include one or more components, such as a vaporizer device. Examples of vaporizer devices consistent with implementations of the current subject matter include electronic vaporizers, electronic nicotine delivery systems (ENDS), and the like. Generally, such vaporizer devices are handheld devices that heat (e.g., by convection, conduction, radiation, and / or some combination thereof) a vaporizable material to provide an inhalable dose of the material. The vaporizable material used with a vaporizer device can be disposed within a cartridge (e.g., a part of a vaporizer that contains the vaporizable material in a reservoir or other container) that can be refillable over time or disposable to allow for use of other vaporizable materials of the same or different type to be loaded. A vaporizer device can be a cartridge- using vaporizer device, a cartridge-less vaporizer device, or a multi-use vaporizer device that can or can not be used with a cartridge. For example, a vaporizer device can include a heating chamber (e.g., an oven or other region in which a material is heated by a heating element) configured to receive a vaporizable material directly into the heating chamber and / or a reservoir or the like for holding the vaporizable material. In some implementations, a vaporizer can be configured to be used with a liquid vaporizable material (e.g., a carrier solution in which active and / or non-active ingredients are suspended or held in solution or a vaporizable material in liquid form itself), a paste, a wax, or a solid vaporizable material. A solid vaporizable material can include plant material that expels a portion of the plant material as the vaporizable material (e.g., certain portions of the plant material remain as waste after the vaporizable material is expelled for inhalation by a user) or, alternatively, can be the vaporizable material itself in solid form such that ultimately all of the solid material can be vaporized for inhalation. A liquid vaporizable material likewise can be completely vaporized or can include a portion of the liquid material that remains after all of the material suitable for inhalation has been consumed.

[0037] Reference Figure 1AA block diagram of the vaporizer device 100 can include a power source 112 (e.g., a battery, which can be a rechargeable battery) and a controller 104 (e.g., a processor capable of executing logic, circuitry, etc.) for controlling the delivery of heat to the atomizer 141 to cause the vaporizable material 102 to transition from a condensed form (e.g., a solid, a liquid, a solution, a suspension, a portion of at least partially unprocessed plant material, etc.) to a gas phase. The controller 104 can be part of one or more printed circuit boards (PCBs) consistent with certain implementations of the current subject matter. After the vaporizable material 102 is transitioned to a gas phase, at least some of the gas phase vaporizable material 102 can condense to form particulate matter in equilibrium at least partially locally with the gas phase as part of an aerosol, which can form some or all of the inhalable dose provided by the vaporizer device 100 during a user’s draw or puff on the vaporizer device 100. It will be appreciated that the interaction between the gas phase and the condensed phase in the aerosol produced by the vaporizer device 100 can be complex and dynamic, as factors such as ambient temperature, relative humidity, chemical properties, flow conditions of the airflow path (both inside the vaporizer and inside the airway of a human or other animal), mixing of the vaporizable material 102 in the gas phase or aerosol phase with other airflows, etc. can affect one or more physical parameters of the aerosol. In certain vaporizers, especially those for delivering volatile vaporizable materials, the inhalable dose can be primarily in the gas phase (i.e., the formation of condensed phase particulate can be very limited).

[0038] The atomizer 141 in the vaporizer device 100 can be configured to vaporize the vaporizable material 102. The vaporizable material 102 can be a liquid. Examples of the vaporizable material 102 include a pure liquid, a suspension, a solution, a mixture, etc. The atomizer 141 can include a wicking element (i.e., a wick) configured to deliver an amount of the vaporizable material 102 to a portion of the atomizer 141 that includes a heating element (not shown in FIG. 1). Figure 1A

[0039] For example, the wicking element can be configured to draw the vaporizable material 102 from a reservoir 140 configured to hold the vaporizable material 102, such that the vaporizable material 102 can be vaporized by heat delivered from the heating element. The wicking element can also optionally allow air to enter the reservoir 140 and displace the volume of vaporizable material 102 that is removed. In some implementations of the current subject matter, capillary action can draw the vaporizable material 102 into the wick to be vaporized by the heating element, and air can return through the wick to the reservoir 140 to at least partially equalize the pressure in the reservoir 140. Other methods of allowing air to return to the reservoir 140 to equalize pressure are also within the scope of the current subject matter.

[0040] ​As used herein, the term "wick" or "wick element" includes any material capable of causing fluid movement via capillary pressure.

[0041] The heating element can include one or more of a conduction heater, a radiation heater, and / or a convection heater. One type of heating element is an electrical resistance heating element, which can include a material (e.g., a metal or an alloy, such as a nichrome alloy or a non-metallic resistor) configured to dissipate electrical energy in the form of heat when an electrical current passes through one or more resistive segments of the heating element. In some implementations of the current subject matter, the atomizer 141 can include a heating element that includes an electrical resistance coil or other heating element that is wrapped around, positioned in, integrated as a unitary shape, pressed into thermal contact with, or otherwise arranged to transfer heat to a wick element to vaporize the vaporizable material 102 drawn out of the reservoir 140 by the wick element for subsequent inhalation by a user in a gas phase and / or a condensed phase (e.g., aerosol particles or droplets). Other wick, heating element, and / or atomizer component configurations are also possible.

[0042] Certain vaporizer devices can additionally or alternatively be configured to produce an inhalable dose of vaporizable material 102 in a gas phase and / or an aerosol phase by heating the vaporizable material 102. The vaporizable material 102 can be a solid phase material (e.g., a wax or the like) or a botanical material (e.g., tobacco leaf and / or a portion of tobacco leaf). In such vaporizer devices, the electrical resistance heating element can be a portion of a wall of an oven or other heating chamber in which the vaporizable material 102 is placed or otherwise incorporated into or in thermal contact with. Alternatively, one or more electrical resistance heating elements can be used to heat air that is passed through or over the vaporizable material 102 to cause convective heating of the vaporizable material 102. In other examples, one or more electrical resistance heating elements can be disposed in close contact with the botanical material such that direct conductive heating of the botanical material occurs within the interior of the botanical material as opposed to only conduction inward from the oven wall.

[0043] The heating element can be activated in association with a user drawing (i.e., puffing, inhaling, etc.) on the mouthpiece 130 of the vaporizer device 100 to cause air to flow from the air inlet along an airflow path through the atomizer 141 (i.e., wicking element and heating element). Optionally, the air can flow from the air inlet through one or more condensation regions or chambers to an air outlet in the mouthpiece 130. The incoming air moving along the airflow path moves over or through the atomizer 141, where the vaporizable material 102 in the gas phase is entrained into the air. The heating element can be activated by the controller 104, which can optionally be part of the vaporizer body 110 discussed herein, causing an electrical current to pass from the power source 112 through a circuit including the resistive heating element, which can be part of the vaporizer cartridge 120 as described herein. The entrained vaporizable material 102 in the gas phase can condense as it passes through the remainder of the airflow path, such that an inhalable dose of the vaporizable material 102 in the form of an aerosol can be delivered from the air outlet (e.g., the mouthpiece 130) for inhalation by the user, as described herein.

[0044] Activation of the heating element can be caused by automatic detection of a draw based on one or more signals generated by one or more of the sensors 113. The sensors 113 and signals generated by the sensors 113 can include one or more of the following: one or more pressure sensors arranged to detect pressure (or optionally measure changes in absolute pressure) along the airflow path relative to ambient pressure, one or more motion sensors (e.g., accelerometers) of the vaporizer device 100, one or more flow sensors of the vaporizer device 100, a capacitive lip sensor of the vaporizer device 100, detection of user interaction with the vaporizer device 100 through one or more input devices 116 (e.g., buttons or other haptic control devices of the vaporizer device 100), receiving a signal from a computing device in communication with the vaporizer device 100, and / or determining that a draw is occurring or about to occur by other methods.

[0045] As discussed herein, the vaporizer device 100 consistent with implementations of the current subject matter can be configured to connect (e.g., wirelessly or via a wired connection) to a computing device (or optionally two or more devices) in communication with the vaporizer device 100. To this end, the controller 104 can include communication hardware 105. The controller 104 can also include memory 108. The communication hardware 105 can include firmware and / or can be controlled by software for performing one or more encryption protocols for communication.

[0046] The computing device can be a component of a vaporizer system that also includes the vaporizer device 100, and can include its own communication hardware that can establish a wireless communication channel with the communication hardware 105 of the vaporizer device 100. For example, a computing device used as part of a vaporizer system can include a general purpose computing device (e.g., a smartphone, a tablet, a personal computer, certain other portable devices such as a smartwatch, etc.) that executes software to produce a user interface for enabling a user to interact with the vaporizer device 100. In other implementations of the current subject matter, such a device used as part of a vaporizer system can be a dedicated hardware, such as a remote control or other wireless or wired device having one or more physical or soft (i.e., configurable on a screen or other display device, and selectable by a user interacting with a touch-sensitive screen or some other input device such as a mouse, a pointer, a trackball, cursor buttons, etc.) interface controls. The vaporizer device 100 can also include one or more outputs 117 or devices for providing information to a user. For example, the outputs 117 can include one or more light-emitting diodes (LEDs) configured to provide feedback to a user based on the status and / or operational mode of the vaporizer device 100.

[0047] In examples in which the computing device provides signals related to activation of the resistive heating element, or in other examples in which the computing device is coupled with the vaporizer device 100 to implement various control or other functions, the computing device executes one or more sets of computer instructions for providing a user interface and underlying data processing. In an example, detection by the computing device of user interaction with one or more user interface elements can cause the computing device to signal the vaporizer device 100 to activate the heating element to reach an operating temperature for producing an inhalable dose of vapor / aerosol. Other functions of the vaporizer device 100 can be controlled by user interaction with a user interface on the computing device in communication with the vaporizer device 100.

[0048] The temperature of the resistive heating element of the vaporizer device 100 can depend on a number of factors, including the amount of electrical power delivered to the resistive heating element, conductive heat transfer to other parts of the electronic vaporizer device 100 and / or to the environment, latent heat losses due to the overall evaporation of the vaporizable material 102 from the wicking element and / or the atomizer 141, and convective heat losses due to airflow (i.e., air flowing over the heating element or the overall atomizer 141 when a user inhales on the vaporizer device 100). As described herein, to reliably activate the heating element or heat the heating element to a desired temperature, in some embodiments of the current subject matter, the vaporizer device 100 can utilize a signal from a sensor 113 (e.g., a pressure sensor) to determine when a user inhales. The sensor 113 can be positioned in the airflow path and / or can be connected (e.g., by a channel or other path) to an airflow path (which includes an inlet for air to enter the vaporizer device 100 and an outlet through which a user inhales the resulting vapor and / or aerosol), such that the sensor 113 experiences a change (e.g., a pressure change) at the same time as air passes through the vaporizer device 100 from the air inlet to the air outlet. In some embodiments of the current subject matter, the heating element can be activated in association with a user’s puff, for example by automatically detecting a puff or by the sensor 113 detecting a change (e.g., a pressure change) in the airflow path.

[0049] The sensor 113 can be positioned on or coupled with (i.e., electrically or electronically connected, either physically or through a wireless connection) the controller 104 (e.g., a printed circuit board component or other type of circuit board). To take accurate measurements and maintain the durability of the vaporizer device 100, it can be beneficial to provide a seal 127 that is sufficiently resilient to separate the airflow path from other portions of the vaporizer device 100. The seal 127 can be a gasket that can be configured to at least partially surround the sensor 113 such that the connection of the sensor 113 to the internal circuitry of the vaporizer device 100 is separated from a portion of the sensor 113 that is exposed to the airflow path. In examples of cartridge-based vaporizers, the seal 127 can also separate portions of one or more electrical connections between the vaporizer body 110 and the vaporizer cartridge 120. This arrangement of the seal 127 in the vaporizer device 100 can help mitigate potentially damaging effects on the vaporizer components due to interaction with environmental factors (e.g., water in the gas or liquid phase, other fluids (e.g., the vaporizable material 102, etc.)) and / or reduce the escape of air from the designated airflow path in the vaporizer device 100. Unwanted air, liquid, or other fluid passing through and / or contacting the circuitry of the vaporizer device 100 can cause various undesirable effects, such as altering pressure readings, and / or can cause harmful substances such as moisture, excess vaporizable material 102, etc. to build up in certain portions of the vaporizer device 100, which can result in weak pressure signals, degradation of the sensor 113 or other components, and / or shorter useful life of the vaporizer device 100. Leaks in the seal 127 can also cause a user to inhale air that has passed through portions of the vaporizer device 100 containing or composed of materials that can not be desirable to inhale.

[0050] In some implementations, the vaporizer body 110 includes the controller 104, a power source 112 (e.g., a battery), one or more of the sensors 113, charging contacts such as those used to charge the power source 112, the seal 127, and a cartridge receiver 118 configured to receive the vaporizer cartridge 120 to couple with the vaporizer body 110 through one or more of various attachment structures. In some examples, the vaporizer cartridge 120 includes a reservoir 140 for containing the vaporizable material 102, and the mouthpiece 130 has an aerosol outlet for delivering an inhalable dose to a user. The vaporizer cartridge 120 can include an atomizer 141 having a wicking element and a heating element. Alternatively, one or both of the wicking element and the heating element can be part of the vaporizer body 110. In implementations where any portion of the atomizer 141 (i.e., the heating element and / or the wicking element) is part of the vaporizer body 110, the vaporizer device 100 can be configured to supply the vaporizable material 102 from the reservoir 140 in the vaporizer cartridge 120 to the portion(s) of the atomizer 141 included in the vaporizer body 110.

[0051] Cartridge-based configurations for vaporizer devices 100 (that produce inhalable doses of non-liquid vaporizable material 102 by heating non-liquid material) are also within the scope of the current subject matter. For example, a vaporizer cartridge 120 can include a quantity of plant material that is treated and formed to be in direct contact with a portion of one or more resistive heating elements, and the vaporizer cartridge 120 can be configured to be mechanically and / or electrically coupled to a vaporizer body 110 that includes a controller 104, a power source 112, and one or more receiver contacts 125a and 125b that are configured to connect to one or more corresponding cartridge contacts 124a and 124b and complete an electrical circuit with the one or more resistive heating elements.

[0052] In embodiments of a vaporizer device 100 where the power source 112 is part of the vaporizer body 110 and the heating elements are disposed in the vaporizer cartridge 120 and configured to couple with the vaporizer body 110, the vaporizer device 100 can include electrical connection features (e.g., means for completing an electrical circuit) for completing an electrical circuit that includes the controller 104 (e.g., a printed circuit board, a microcontroller, etc.), the power source 112, and the heating elements (e.g., heating elements within the atomizer 141). These features can include one or more contacts on a bottom surface of the vaporizer cartridge 120 (referred to herein as cartridge contacts 124a and 124b) and at least two contacts disposed near the bottom of the cartridge receiver 118 of the vaporizer device 100 (referred to herein as receiver contacts 125a and 125b), such that when the vaporizer cartridge 120 is inserted into and coupled with the cartridge receiver 118, the cartridge contacts 124a and 124b form an electrical connection with the receiver contacts 125a and 125b. The electrical circuit completed by these electrical connections can allow for the delivery of electrical current to the heating elements, and can also be used for other functions, such as measuring the electrical resistance of the heating elements in order to determine and / or control the temperature of the heating elements according to the thermal resistance coefficient of the heating elements.

[0053] In some embodiments of the present subject matter, cartridge contacts 124a and 124b and receiver contacts 125a and 125b can be configured to be electrically connected in any of at least two orientations. In other words, by inserting the evaporator cartridge 120 into the cartridge receiver 118 in a first rotational orientation (along the axis along which the evaporator cartridge 120 is inserted into the cartridge receiver 118 of the evaporator body 110), such that cartridge contact 124a is electrically connected to receiver contact 125a and cartridge contact 124b is electrically connected to receiver contact 125b, one or more circuits required for the operation of the evaporator device 100 can be completed. Furthermore, the one or more circuits required for the operation of the evaporator device 100 can be completed by inserting the evaporator cartridge 120 into the cartridge receiver 118 in a second rotational orientation, such that cartridge contact 124a is electrically connected to receiver contact 125b and cartridge contact 124b is electrically connected to receiver contact 125a.

[0054] In one example of an attachment structure for coupling evaporator cartridge 120 to evaporator body 110, evaporator body 110 includes one or more stops (e.g., recesses, protrusions, etc.) projecting inward from the inner surface of cartridge receiver 118, formed to include additional material (e.g., metal, plastic, etc.) and / or the like, including portions protruding into cartridge receiver 118. One or more outer surfaces of evaporator cartridge 120 may include corresponding recesses ( Figure 1A (Not shown in the image), when the evaporator cartridge 120 is inserted into the cartridge receiver 118 on the evaporator body 110, the corresponding recess may fit and / or otherwise engage with these stops or protrusions. When the evaporator cartridge 120 and the evaporator body 110 are coupled (e.g., by inserting the evaporator cartridge 120 into the cartridge receiver 118 of the evaporator body 110), the stops or protrusions of the evaporator body 110 may fit into the recesses of the evaporator cartridge 120, and / or otherwise remain within the recesses of the evaporator cartridge 120 to hold the evaporator cartridge 120 in place after assembly. Such a component can provide sufficient support to hold the evaporator feed box 120 in place to ensure good contact between the feed box contacts 124a and 124b and the receiver contacts 125a and 125b, while allowing the evaporator feed box 120 to be released from the evaporator body 110 when the user pulls the evaporator feed box 120 with reasonable force, so that the evaporator feed box 120 is detached from the feed box receiver 118.

[0055] In some implementations, the vaporizer cartridge 120 or at least the insertable end 122 of the vaporizer cartridge 120 that is configured for insertion into the cartridge receiver 118 can have a non-circular cross-section transverse to the axis along which the vaporizer cartridge 120 is inserted into the cartridge receiver 118. For example, the non-circular cross-section can be approximately rectangular, approximately elliptical (i.e., having an approximately oval shape), non-rectangular but having two sets of parallel or approximately parallel opposite sides (i.e., having a shape similar to a parallelogram), or other shapes having at least second-order rotational symmetry. In this context, approximately shape indicates that substantial similarity to the described shape is apparent, but the sides of the shape in question need not be perfectly linear and the vertices need not be perfectly sharp. Rounding of two or either of the edges or vertices of the cross-sectional shape is contemplated in the description of any non-circular cross-section referred to herein.

[0056] The cartridge contacts 124a and 124b and the receiver contacts 125a and 125b can take various forms. For example, one or both sets of contacts can include electrically conductive pins, tabs, posts, receiving holes for pins or posts, etc. Certain types of contacts can include springs or other features to facilitate better physical and electrical contact between the contacts on the vaporizer cartridge 120 and the contacts on the vaporizer body 110. The electrical contacts can optionally be gold plated, and / or include other materials.

[0057] Figure 1B An embodiment of the vaporizer body 110 and cartridge receiver 118 is shown, into which a vaporizer cartridge 120 can be releasably inserted. Figure 1B A top view of the vaporizer device 100 is shown, illustrating a vaporizer cartridge 120 positioned for insertion into the vaporizer body 110. As a user draws on the vaporizer device 100, air can pass between the outer surface of the vaporizer cartridge 120 and the inner surface of the cartridge receiver 118 on the vaporizer body 110. The air is then drawn to the insertable end 122 of the cartridge, through a vaporization chamber that includes or contains a heating element and wick, through the outlet of the mouthpiece 130 for delivery to the user as an inhalable aerosol. The reservoir 140 of the vaporizer cartridge 120 can be formed in whole or in part from a translucent material, such that the level of vaporizable material 102 is visible within the vaporizer cartridge 120. The mouthpiece 130 can be a separable component of the vaporizer cartridge 120 or can be integrally formed with one or more other components of the vaporizer cartridge 120 (e.g., integrally formed with the reservoir 140, etc.).

[0058] In addition to the above-discussed reversibility of the electrical connection between the vaporizer cartridge 120 and the vaporizer body 110 such that at least two rotational orientations of the vaporizer cartridge 120 in the cartridge receiver 118 are possible, in some embodiments of the vaporizer device 100, the shape of the vaporizer cartridge 120 or the shape of at least the insertable end 122 of the vaporizer cartridge 120 configured to be inserted into the cartridge receiver 118 can have rotational symmetry of at least the second order. In other words, the vaporizer cartridge 120 or at least the insertable end 122 of the vaporizer cartridge 120 can be symmetrical upon a 180° rotation about an axis along which the vaporizer cartridge 120 is inserted into the cartridge receiver 118. In such a configuration, the circuitry of the vaporizer device 100 can support the same operations regardless of which symmetrical orientation of the vaporizer cartridge 120 occurs.

[0059] Figures 1C-1D An example feature that can be included in embodiments of the vaporizer device 100 consistent with implementations of the current subject matter is shown. Figure 1C and 1D Pictorial views of an example of the vaporizer device 100 are shown before Figure 1C ) and after Figure 1D ) connecting the vaporizer cartridge 120 to the vaporizer body 110.

[0060] Figure 1E A perspective view of one variation of the vaporizer cartridge 120 holding a vaporizable material 102 is shown. Any suitable vaporizable material 102 can be contained within the vaporizer cartridge 120 (e.g., within the reservoir 140), including a solution of nicotine or other organic material.

[0061] Figure 1FA perspective view showing another example of a vaporizer device 100 including a vaporizer body 110 coupled to a separable vaporizer cartridge 120 is shown. As shown, the vaporizer device 100 can include one or more outputs 117 (e.g., LEDs) configured to provide information to a user based on a state, mode of operation, etc. of the vaporizer device 100. In certain aspects, the one or more outputs 117 can include a plurality of LEDs (i.e., two, three, four, five, or six LEDs). The one or more outputs 117 (i.e., each individual LED) can be configured to display light in one or more colors (e.g., white, red, blue, green, yellow, etc.). The one or more outputs 117 can be configured to display different light patterns (e.g., by illuminating particular LEDs, varying the light intensity of one or more LEDs over time, illuminating one or more LEDs in different colors, etc.) to indicate different states, modes of operation, etc. of the vaporizer device 100. In some implementations, the one or more outputs 117 can be proximate to and / or at least partially disposed within a bottom end region 160 of the vaporizer device 100. Additionally or alternatively, the vaporizer device 100 can include externally accessible charging contacts 128 that can be proximate to and / or at least partially disposed within the bottom end region 160 of the vaporizer device 100.

[0062] Figure 1G is a system block diagram illustrating an example of a conventional PWM heater controller 160. The heater controller includes a battery charger 162, a microcontroller 164, a PWM metal oxide semiconductor field effect transistor (MOSFET) 165, a voltage measurement point (VMEAS) analog front end (AFE) 185, a low dropout regulator (LDO) 174, and a current source 182. The PWM heater controller 160 can include contacts 181 for coupling to a pod 180 containing a heating element 185 and a vaporizable material. The PWM heater controller 160 can also be coupled to a battery 172. The microcontroller 164 can control the PWM MOSFET 165 to switch the current source 182 or the battery 172 in unison with the heating element 185 to provide power to the heating element 185 for heating.

[0063] In conventional PWM control, power is provided directly from the battery 172 and turned on and off by solid state switches such as PWM MOSFET 165. The heater resistance can be measured between PWM pulses by flowing a known constant current through the heater and measuring the voltage drop across the heating element 185. In some existing vaporizer atomizers, heater control is achieved by pulse width modulation of the power source (e.g. battery) being delivered to the heating element. As described below, conventional PWM methods can control the heating element, however, PWM control can not tolerate large variations in heater and pod contact resistance, can require the power source to be interrupted to measure heater resistance, can shorten battery run time, can cause run time to be shortened at lower temperatures, can cause the battery to age more quickly, system integration can be limited, TCR can be limited and / or can result in increased number of components and cost to measure heater resistance.

[0064] Some PWM implementations can not tolerate large variations in heater and pod contact resistance. PWM control can be limited to a maximum duty cycle. At low battery voltage, PWM control can not compensate for an increase in pod contact resistance to maintain target power. PWM control can require tighter heater resistance tolerances in production to ensure target power of the heater can be reached at low voltage. PWM control can reduce usability, that is, the user can need to clean the pod contacts frequently.

[0065] PWM control interrupts power to measure heating element temperature. It can be difficult to directly measure the power of the heater due to PWM switching. For the same reason, it can be difficult to measure the heater resistance between PWM pulses, so the power of the heater is typically interrupted for measurement. PWM control can require more complex circuitry, such as a stable constant current source and a Wheatstone bridge to measure resistance.

[0066] PWM control can result in shorter vaporizer battery run time. There is a minimum battery voltage limit to reach target power. For the example above, an 8.0W target power requires a minimum of about 3.4V voltage at load. Below about 3.4V load voltage, the PWM duty cycle is 100% and the system cannot provide target power. This will negatively impact user experience in low charge state. For an aged battery, the minimum voltage limit is reached at even higher state of charge, thus shortening run time.

[0067] PWM control can result in shorter vaporizer run time at low temperature. Battery impedance (DCIR) increases at low temperature, even around 15°C. This causes the battery voltage to drop at load and can reduce user experience and shorten operation time. This effect is greater at low temperature below 10°C, resulting in a large reduction in run time.

[0068] PWM control can result in faster battery aging. Because the heater resistance is lower, the current in the PWM pulse is higher at the average battery voltage and at high voltage. This results in higher polarization in the battery, higher stress, faster aging, and shorter cycle life.

[0069] PWM control can result in limited system integration. PWM control charging and heater power control are independent circuits, requiring more circuit board area. PWM control can require a relatively low heater element resistance, limiting design options.

[0070] PWM control can result in limited heater TCR selection options. Higher TCRs provide a larger resistance change with temperature, a larger signal, and thus better temperature measurement accuracy. However, PWM control can require a low TCR to maintain heater power at low battery voltage.

[0071] PWM control can result in increased component count and increased cost to measure heater resistance. For example, additional current sources and a Wheatstone bridge circuit can increase component count.

[0072] The subject matter described herein provides a number of technical advantages over conventional PWM control and other heating element control techniques. For example, the current subject matter can enable improved system integration. In some implementations, the charger and heater power control can be built into one DC-DC converter. A single inductor can be used to charge and power the heater. The combination of charger and heater control circuitry can provide cost reduction and / or space reduction.

[0073] In some implementations, the current subject matter can enable reduced board area, which can allow for greater battery capacity or a smaller overall vaporizer device. Lower total cost can be achieved, allowing for significant variation in heater and pod contact resistance, etc. The output voltage can vary in proportion to the increase in load resistance to maintain power. This can compensate for larger variations in pod contact resistance and allow for looser production tolerances of the heating element.

[0074] In some implementations, the current subject matter can improve usability by automatically compensating for variations in contact resistance, requiring less cleaning of the contacts.

[0075] In some implementations, the current subject matter enables measurement of the heater element while it is being heated. For example, uninterrupted power can be provided to the heater while heater power can also be measured directly during heating. A simpler measurement circuit can be achieved due to the DC output of the converter.

[0076] In some embodiments, the current subject matter can enable longer battery run time, allowing the battery cell to discharge deeper under load to 3.0V or even lower, to run longer within target performance, and / or enable improved performance at low ambient temperatures (e.g., in cold weather). For example, battery voltage can drop at low temperatures, while the converter can still maintain constant power to the heater and / or provide longer run time at low temperatures.

[0077] In some embodiments, the current subject matter can improve battery cycle life, reduce battery stress due to lower peak discharge current, enable higher system integration, such as charger and heater power control can be built into one integrated DC-DC converter, charging and powering the heating element using the same single inductor (i.e., inductor shared by charger and heater power control), and / or reduce the circuit board area required for heater control, allowing for greater battery capacity or smaller device, and / or reducing overall cost.

[0078] Some embodiments can enable less heat dissipation during charging, less heat transfer to the charger temperature sensor (typically a negative temperature coefficient (NTC) mounted on the battery cell) allowing accurate battery temperature measurement, enable high charging efficiency from battery-powered charging accessories, and / or save energy compared to linear chargers.

[0079] Some embodiments can provide an alternative heater resistance measurement with low excitation current and without self-heating, which can be achieved by adding at least a resistor in series with the heater and power FET.

[0080] The current subject matter relates to heating control of a vaporizer cartomizer using a direct current-direct current (DC-DC) converter and a power monitor that can measure the current flowing through the heater and the voltage across the heating element to calculate the power and impedance. The output voltage of the converter can be controlled to maintain a target power and / or a target temperature on the heating element. By utilizing DC-DC converter control, the current subject matter can enable one or more of continuous heater resistance and temperature monitoring as power varies, provide faster preheat and consistent power curve at low battery voltage and temperature, enable reduced cost and space with combined charger and heater control circuitry, compensate for increase in pod contact resistance and improve user experience, allow higher heater TCR when the heating element is close to ambient temperature without overloading the battery, thereby improving efficiency at low battery voltage, improving battery run time, providing consistent performance at lower temperatures, and / or prolonging battery life.

[0081] Figure 2is a system block diagram illustrating an example heater power control 200 in accordance with some aspects of the current subject matter. The heater power controller 200 can include a buck-boost DC-DC converter 205 and a power monitor 210. In some implementations, the heater power controller 200 is part of the circuitry of the controller 104 described above.

[0082] The converter 205 can be electrically coupled to a power source (e.g., a battery 215 and / or a universal serial bus (USB) power source 220) and a heating element 225 located in a pod 230. The converter 205 can be coupled to the heating element 225 via a contact 235. The converter can receive a first voltage (e.g., V BAT or V USB ) from the power source (e.g., 215 or 220) and provide a second voltage (e.g., V HEAT+ ) to the heating element 225.

[0083] The power monitor 210 can be electrically coupled to the heating element 225 and can include a microprocessor 211, an analog-to-digital converter 212, and an analog front end 213. The power monitor 210 can measure the current flowing through the heating element 225, measure the voltage across the heating element (e.g., voltage drop from V HEAT+ to V HEAT- ), calculate the power and / or resistance, and output a control signal (e.g., DC EN) to the converter 205.

[0084] The converter 205 can be controlled by the control signal (e.g., DC EN) to vary the second voltage (e.g., V HEAT+ ) to maintain a target power or a target temperature on the heating element 225. By utilizing the converter 205 and the power monitor 210 to maintain a target power or a target temperature on the heating element 225, an improved vaporizer atomizer can be achieved.

[0085] In some implementations, the converter 205 can include an energy storage component 240. For example, the converter 205 can utilize a capacitor as the energy storage component 240 in a switched capacitor or charge pump topology. However, to limit the peak current drawn from the battery 215, as Figure 2 indicated, the converter 205 can include an inductor as the energy storage component 240. A converter based on an inductor can be used to step down a voltage (e.g., buck), step up a voltage (e.g., boost), or adjust within a battery voltage range (e.g., buck-boost).

[0086] In some embodiments, closed loop control of the converter 205 can be implemented with a power monitor 210 that includes analog circuitry to measure voltage and current and output analog signals to control the converter. In some embodiments, closed loop control can be implemented, for example, by an analog front end (AFE) circuit to obtain voltage and current information. The power monitor 210 can include a digital converter 212 with a digital control output signal such as PWM, a digital to analog converter (DAC) signal, or an integrated circuit bus format signal (I2C). The power monitor 210 can measure the voltage across the heating element 225 and the current through the heating element 225 to calculate the electrical power dissipated in the heating element 225 and the resistance of the heating element 225. Unlike traditional PWM methods, this can be performed continuously without interrupting the power to the heating element.

[0087] In some embodiments, the current subject matter can utilize a 4-wire (Kelvin) connection (e.g., four contacts 235) for precise voltage measurements on the heating element 225. In some embodiments, the current subject matter can utilize a 2-wire pod connection (e.g., two contacts 235) or a 3-wire connection.

[0088] In some embodiments, a 5V power supply can be provided to enable the DC-DC converter 205 to charge other electronic devices from the internal battery 215. In this case, the converter outputs 5V as a USB power supply. In this implementation, the converter can operate in one of three modes: 1) as a charger, 2) for heater control, or 3) as a USB power supply.

[0089] Some embodiments can allow for a higher heater TCR. A higher TCR can provide a larger AR / AT signal (resistance change / temperature change) and more accurate temperature measurements. Some embodiments can allow for pod contact resistance diagnostics, where changes in the output current can be analyzed to sense an increase in contact resistance.

[0090] Figure 3 is a graph showing Figure 2 the operating modes of the example heater power controller 200 shown in FIG. 2. The graph shows the voltage versus time for the device in the off “shipping” mode, when a charger is connected (e.g., charging mode), during a puff, when the charger is disconnected (“discharge mode”), resting, charging mode, and resting.

[0091] In some embodiments, the DC-DC converter can be used as a constant current source. In some embodiments, the DC-DC converter can provide a constant current to measure the heater resistance between puffs. This can convert the constant voltage output to a current source. Figure 4is a system block diagram showing an example heater controller 400, where the converter 205 is used as a current source. The example heater controller 400 includes a resistor 405 and a switch 410 (MOSFET) in series with the heating element 225. The switch 410 is controlled by the power monitor 210.

[0092] The current can be set by the value of the resistor 405, R ISET , and in some embodiments can be selected around 10-100 mA. The power monitor 210 can measure the voltage across the heating element 225 and the current through the heating element 225 to calculate the resistance.

[0093] In an example embodiment, the heating element 225 can include a positive temperature coefficient of resistance (TCR) of +5% at temperatures above ambient of 250°C. At operating temperatures, the heater power can be 8 Watts (W), the resistance of the heating element 225 (R h ) = 0.5 Ohms (Ω), and the parasitic resistance Rp= 0.35 Ω. The voltage on the heater can be initially set to 2.00 V. As the heating element 225 heats up, its resistance increases to 0.525 Ω = 0.5 Ω x 1.05, and the heater voltage also increases to 2.05 V to maintain the 8 W power on the heater. Note that the actual output voltage of the DC-DC converter is higher, 2.80 V at the start of heating and 2.83 V at the target temperature, to compensate for the voltage drop across the parasitic resistance.

[0094] Assuming an efficiency of 93% for the DC-DC converter, the overall efficiency of this DC-DC circuit can be about 56%, or about 15% lower than PWM control, which will be described more fully below. To improve the efficiency, the output voltage can be increased to 4.5 V. This can result in R h increasing to 2.11 Ω. The average efficiency improves to about 75%. In this case, the converter efficiency is about 4% higher than the PWM efficiency.

[0095] In some embodiments, a higher heater resistance can be utilized for high efficiency, the power monitor can incorporate filtering to improve voltage and current measurement accuracy, and the present subject matter can utilize a converter with improved internal power field effect transistor (FET) design for lower resistance R DS(on) and faster switching to achieve higher efficiency.

[0096] In some embodiments, hybrid heater control can be implemented by combining a DC-DC converter with a PWM control circuit to improve the overall efficiency of the vaporizer device. For example, PWM can be used at high battery voltage and provide a boost at low battery voltage or low temperature or to compensate for an increase in the resistance of the pod contacts. The DC-DC converter can be set to run at a relatively high efficiency (for a DC-DC converter) and can be turned on and off when the output power needed is less than the full output power. In this way, the PWM control circuit can supplement the DC-DC converter in providing power to the heating element or can provide PWM power only to the heating element when the DC-DC converter is off.

[0097] In some embodiments, a method of hybrid heater control includes measuring a power supply output voltage (e.g., a battery output voltage) and selecting an operating circuit (e.g., by using a controller or by using an automatic voltage switch) to power a heating element. In some embodiments, the method includes powering the heating element with a PWM control circuit when the power supply output voltage is greater than or equal to 4.0 V, and powering the heating element with a DC-DC converter control circuit when the power supply output voltage is less than 4.0 V. In some embodiments, the method includes powering the heating element with a PWM control circuit when the power supply output voltage is greater than or equal to 3.8 V, and powering the heating element with a DC-DC converter control circuit when the power supply output voltage is less than 3.8 V. In some embodiments, the method includes powering the heating element with a PWM control circuit when the power supply output voltage is greater than or equal to 3.6 V, and powering the heating element with a DC-DC converter control circuit when the power supply output voltage is less than 3.6 V. In some embodiments, the method includes powering the heating element with a PWM control circuit when the power supply output voltage is greater than or equal to 3.4 V, and powering the heating element with a DC-DC converter control circuit when the power supply output voltage is less than 3.4 V.

[0098] In some embodiments, the method of hybrid heater control includes measuring a duty cycle of a PWM control circuit powering a heating element (e.g., by using a controller), and switching to a DC-DC converter control circuit to power the heating element when the duty cycle is greater than 85%. In some embodiments, the method of hybrid heater control includes measuring a duty cycle of a PWM control circuit powering a heating element (e.g., by using a controller), and switching to a DC-DC converter control circuit to power the heating element when the duty cycle is greater than 90%. In some embodiments, the method of hybrid heater control includes measuring a duty cycle of a PWM control circuit powering a heating element (e.g., by using a controller), and switching to a DC-DC converter control circuit to power the heating element when the duty cycle is greater than 95%. In some embodiments, the method of hybrid heater control includes measuring a duty cycle of a PWM control circuit powering a heating element (e.g., by using a controller), and switching to a DC-DC converter control circuit to power the heating element when the duty cycle is greater than 98%. In some embodiments, the method of hybrid heater control includes measuring a duty cycle of a PWM control circuit powering a heating element (e.g., by using a controller), and switching to a DC-DC converter control circuit to power the heating element when the duty cycle is approximately 100%.

[0099] Figure 5 is a process flow diagram illustrating an example process 500 of operating a heater controller in accordance with some aspects of the current subject matter. At 510, a current through a heating element of a vaporizer cartomizer can be measured. The current can be provided by a converter configured to be electrically coupled to a power source and the heating element. The converter can be further configured to receive a first voltage from the power source and to provide a second voltage to the heating element. The converter can be a DC-DC converter.

[0100] At 520, a voltage across the heating element can be measured. At 530, a power and / or a resistance can be calculated. At 540, operation of the converter can be controlled to vary the second voltage to maintain a target power or a target temperature across the heating element.

[0101] The following includes exemplary PWM control implementations that can supplement the DC-DC converter in providing power to the heating element, or can provide PWM power only to the heating element when the DC-DC converter is off. A typical lithium-ion battery cell discharges from full to empty with a working voltage range of about 4.2V to 3.0V. To ensure there is enough voltage to reach the target power and temperature, the resistance of the heating element (Rh) is selected for the minimum working voltage at maximum PWM duty cycle (D). The current and power in the PWM pulse is proportional to the voltage, given by Ohm’s law Ih = Vb / R, where: Ih is the current, Vb is the battery voltage, and R is the resistance. R includes all the resistances in the electrical power path between the chemical battery positive and negative and the atomizer.

[0102] In some implementations, the resistance R can be represented as the sum of the following resistances: Rb: internal cell impedance (DCIR); Rs: battery safety electronics, FET and PWM switch; Rt: conductor resistance, wires, PCBA traces, electrical interconnections; Rc: pod contact resistance; Rh: resistive heating element (atomizer). For simplicity, the parasitic resistance can be represented as Rp = Rb + Rs + Rt + Rc. Then the total resistance in the circuit is R = Rh + Rp. Figure 6 An example circuit diagram is shown that illustrates the resistances and related parameters in an example electrical power path, and includes a power control switch. Note that in the calculations, the resistances in the positive and negative rails are represented as a single resistance.

[0103] For PWM control calculations and a target power of 8.0W on the heating element, the power from the battery can be represented as Pb = Ph + Pp, where: Pb is the power drawn from the battery, Ph is the power on the heating element, and Pp is the power loss on the sum of all parasitic resistances. Similarly, the battery voltage Vb can be represented as the sum of the voltage on the heating element Vh and the voltage on the parasitic resistances Vp, as Vb = Vh + Vp. Vh = Rh x I and Vp = Rp x I can be substituted to yield Vb = I x (Rh + Rp). Rh can be selected, for example, for Ph > 8.0W at maximum duty cycle and minimum battery voltage, where Rb = 200mΩ (for a small lithium-ion battery); Rs = 60mΩ; Rt = 60mΩ; Rc = 30mΩ; Rp = 0.35Ω.

[0104] R = 0.50 Ω can be chosen at the minimum battery voltage of 3.40 V. The total resistance in the circuit is R = Rp+ Rh= 0.35 Ω + 0.5 Ω = 0.85 Ω. The peak current in the PWM pulse during heating is I = 3.4 V / 0.85 Ω = 4.0 A. For the example above, this is the current at different states of charge: 4 A at the minimum battery voltage of 3.4 V; 5.28 A at the average battery voltage of 3.7 V; and 6.74 A at the maximum battery voltage of 4.2 V. The average power drawn from the battery at 3.70 V is 11.22 W, with an electrical efficiency of 71.3%. Note that the power loss is independent of the duty cycle, as the power to the heating element is only delivered in the PWM pulse.

[0105] The subject matter described herein can be embodied in systems, apparatus, methods, and / or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all of the implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and / or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and / or described herein do not necessarily require the particular order shown, or sequential order, to achieve the desired results. Other implementations can be within the scope of the following claims.

[0106] The term

[0107] When a feature or element is herein referred to as being "on" another feature or element, it can be directly on the other feature or element or intervening features and / or elements can also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be appreciated by those of skill in the art that references to a feature or element being "connected", "attached", or "coupled / coupled to" another feature or element, can include indirect connections, attachments, or couplings / couplings to the other feature or element through intervening features or elements. In contrast, a feature or element that is "directly connected", "directly attached" or "directly coupled / coupled to" another feature or element is connected, attached, or coupled / coupled to the other feature or element without intervening features or elements.

[0108] Although described or shown with respect to one embodiment, features and elements so described or shown can be used in other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is positioned "adjacent" another feature can have portions that overlap or underlie the adjacent feature.

[0109] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0110] In the descriptions above and in the claims, there can be phrases that occur after a list of elements or features, such as "at least one of" or "one or more of". The term "and / or" can also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases "at least one of A and B; one or more of A and B; and A and / or B" each mean "A alone, B alone, or A and B together." Similar explanations apply with respect to lists of three or more items. For example, the phrases "at least one of A, B, and C; one or more of A, B, and C; and A, B, and / or C" each mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together." The use of the term "based on," above and in the claims is intended to mean "based, at least in part, on" such that an unrecited feature or element is also permissible.

[0111] Spatially relative terms, such as "forward", "rearward", "lower", "down", "upper", "up", "bottom", "top", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device is inverted or rotated by 90 degrees, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly", "downwardly", "vertical", "horizontal", and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0112] Unless otherwise stated, as used herein the terms "first" and "second" can be used to describe various features / elements (including steps) including without limitation two or more features / elements. The terms are used herein, inter alia, to differentiate one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element and, similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings provided herein.

[0113] As used in the specification and in the claims, the use of the term "about" or "approximately" in connection with a value means that the value is near to the stated value and can include the stated value and / or a reasonable range around the stated value. For example, "about 45 degrees" can include 45 degrees and a reasonable range of values around 45 degrees, such as 1%, 5%, or 10% of the value of 45 degrees. When describing amplitude and / or position to indicate that the described value and / or position is within a reasonable expected range of values and / or positions, the phrases "about" or "approximately" can be used. For example, a numerical value can be the stated value (or range of values) + / - 0.1%, the stated value (or range of values) + / - 1%, the stated value (or range of values) + / - 2%, the stated value (or range of values) + / - 5%, the stated value (or range of values) + / - 10%, etc. Unless otherwise stated, any numerical value given herein should also be understood as including about or approximately that value. For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed

[0114] Although various illustrative embodiments are described above, any alterations and / or changes can be made without departing from the teachings of the present disclosure. For example, the order of executing the various described method steps can frequently be altered in alternative implementations. Also, various described apparatus and system implementations can include optional features that can or can not be implemented. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the claims.

[0115] One or more aspects or features of the subject matter described herein can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) computer hardware, firmware, software, and / or combinations thereof. These various aspects or features can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, output data to, and / or

[0116] These computer programs, also referred to as programs, software, software applications, applications, devices or code, include machine instructions for the programmable processor, and can be implemented in a high-level procedural and / or object-oriented programming language, a functional programming language, a logical programming language, and / or in assembly / machine language. As used herein, the term "machine-readable medium" refers to any computer program product, apparatus and / or device, including a memory, a disk, an optical disk (e.g., CD or DVD, etc.), and a programmable logic device (PLD), used to provide machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as a non-transient solid-state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or in addition transmit such machine instructions in a transient manner, such as in those represented by signal as encountered during transmission from one machine to another to the internet or other networked system.

[0117] The examples and illustrations included herein show specific embodiments in which the subject matter can be practiced by way of illustration and not limitation. As stated above, other embodiments can be utilized and derived therefrom, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. Such embodiments of the subject matter of the invention may be referred to herein individually or collectively by the term "invention," and if more than one invention is disclosed in fact, it is not intended to voluntarily limit the scope of this application to any single invention or inventive concept but merely for convenience. Thus, although particular embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may replace the particular embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various implementations. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reading the above description. The use of the term "based on" in this document and in the claims is intended to mean "at least partially based on," thereby also allowing for features or elements not described herein.

[0118] Depending on the desired configuration, the subject matter described herein can be embodied in systems, apparatuses, methods, and / or articles. The embodiments set forth in the foregoing description do not represent all embodiments consistent with the subject matter described herein. Rather, they are merely some examples consistent with aspects related to the described subject matter. Although some variations have been described in detail herein, other modifications or additions are possible. In particular, other features and / or variations may be provided in addition to those features and / or variations set forth herein. For example, the embodiments described herein can be for various combinations and sub-combinations of the disclosed features and / or combinations and sub-combinations of several other features disclosed herein. Furthermore, the logical flows depicted in the drawings and / or described herein do not necessarily require the specific order or sequential order shown to achieve the desired results. Other embodiments are within the scope of the appended claims.

Claims

1. A system comprising: a converter configured to be electrically coupled to a power source and a heating element of a vaporizer atomizer, the converter further configured to receive a first voltage from the power source and provide a second voltage to the heating element, the converter comprising a DC-DC converter control circuit to step up or step down the first voltage of the power source to provide the second voltage, and a pulse width modulation control circuit configured to be electrically coupled to the power source and the heating element of the vaporizer atomizer, the pulse width modulation control circuit further configured to selectively provide the second voltage to the heating element; and circuitry configured to be electrically coupled to the heating element, measure a current through the heating element and / or a voltage across the heating element, calculate a power and / or a resistance, and output a control signal to the converter, wherein the converter is configured to be controlled by the control signal to vary the second voltage to maintain a target power or a target temperature on the heating element, wherein the system is configured to select the DC-DC converter control circuit or the pulse width modulation control circuit to provide the second voltage to the heating element based on the first voltage or a duty cycle of the pulse width modulation control circuit.

2. The system of claim 1, wherein, the converter comprises a boost and / or a buck converter, the converter comprises an energy storage device.

3. The system of claim 2, wherein, the energy storage device comprises a capacitor in a switched capacitor topology or a charge pump topology.

4. The system of claim 2, wherein, the energy storage device comprises an inductor.

5. The system of claim 1, wherein, the circuitry comprises analog circuitry forming a closed loop control.

6. The system of claim 1, wherein, the circuitry comprises: analog front end circuitry configured to measure a current through the heating element and a voltage across the heating element; and a digital converter comprising circuitry configured to provide the control signal based on the measured current through the heating element and the measured voltage across the heating element.

7. The system of claim 6, wherein, the digital converter is configured to provide the control signal as a pulse width modulation signal, a digital to analog conversion signal, or an internal integrated circuit format signal.

8. The system of any one of claims 1 to 7, wherein, the circuitry continuously measures the current and the voltage without interrupting power to the heating element.

9. The system of any of claims 1 to 7, further comprising: a microcontroller; and a switch between the converter and the heating element, the switch electrically coupled to the microcontroller, the microcontroller configured to apply a pulse width modulation signal to a gate of the switch. the converter is configured to operate at a first power level, and the microcontroller is configured to determine a second power level based on the measured current through the heating element and the measured voltage across the heating element and modify the pulse width modulation signal to control the switch to modify the second voltage.

10. The system of claim 9, wherein, the converter is configured to provide uninterrupted power to the heating element during a heating cycle.

11. The system of any one of claims 1 to 10, wherein, the circuitry is configured to determine a change in a contact resistance of a contact between the converter and the heating element based on a change in the measured current.

12. The system of any one of claims 1 to 11, wherein, 13. The system of any of claims 1 to 12, further comprising: ​ a current source configured to be coupled to the heating element, the current source comprising a current source resistor and a current source switch.

14. The system of any of claims 1-13, further comprising: a universal serial bus port comprising a universal serial bus power rail, the converter configured to output a third voltage to the universal serial bus power rail.

15. The system of any one of claims 1 to 14, wherein, the power source is a battery.

16. The system of any one of claims 1 to 15, wherein, the circuit comprises a 3-wire or 4-wire connection for measuring the voltage across the heating element.

17. An integrated converter comprising: a converter configured to be electrically coupled to a power source and a heating element of a vaporizer atomizer, the converter further configured to receive a first voltage from the power source and provide a second voltage to the heating element, the converter comprising a DC-DC converter control circuit to step up or step down the first voltage of the power source to provide the second voltage, and a pulse width modulation control circuit configured to be electrically coupled to the power source and the heating element of the vaporizer atomizer, the pulse width modulation control circuit further configured to selectively provide the second voltage to the heating element, a circuit configured to be electrically coupled to the heating element, measure a current through the heating element and / or a voltage across the heating element, calculate a power and / or a resistance, and output a control signal to the converter, the circuit comprising a 3-wire or 4-wire connection for measuring the voltage across the heating element, and a charger configured to be electrically coupled to the power source to charge the power source, wherein the converter is configured to be controlled by the control signal to change the second voltage to maintain a target power or a target temperature across the heating element, wherein the integrated converter is configured to select the DC-DC converter control circuit or the pulse width modulation control circuit to provide the second voltage to the heating element based on the first voltage or a duty cycle of the pulse width modulation control circuit.

18. The integrated converter of claim 17, wherein, the converter and the charger comprise a common inductor to power the heating element and charge the power source.

19. A method comprising: providing a current by a converter configured to be electrically coupled to a power source and a heating element, the converter further configured to receive a first voltage from the power source and provide a second voltage to the heating element, the converter comprising a DC-DC converter control circuit to step up or step down the first voltage of the power source to provide the second voltage, and a pulse width modulation control circuit; measuring a voltage across the heating element and / or a current through the heating element; determining the first voltage or a duty cycle of the pulse width modulation control circuit; selecting the DC-DC converter control circuit or the pulse width modulation control circuit to provide the second voltage to the heating element; and changing the second voltage to maintain a target power or a target temperature across the heating element.

20. The method of claim 19, wherein, the converter comprises a boost and / or buck converter, the converter comprising an energy storage device.

21. The method of claim 20, wherein, the energy storage device comprises a capacitor in a switched capacitor topology or a charge pump topology.

22. The method of claim 20, wherein, the energy storage device comprises an inductor.

23. The method of claim 19, further comprising: providing a control signal to the converter as a pulse width modulated signal, a digital to analog converted signal, or a built-in integrated circuit format signal.

24. The method of claim 19, further comprising: applying a pulse width modulated signal to a gate of a switch coupled between a microcontroller, the converter, and the heating element.

25. The method of claim 24, wherein, the converter is configured to operate at a first power level, and the microcontroller is configured to determine a second power level based on a measured current through the heating element and a measured voltage across the heating element and modify the pulse width modulated signal to control the switch to modify the second voltage.

26. The method of claim 19, wherein, the converter is configured to provide uninterrupted power to the heating element during a heating cycle.

27. The method of claim 19, further comprising: determining a change in a contact resistance of a contact between the converter and the heating element based on a change in the measured current.

28. The method of any one of claims 19 to 27, wherein, measuring the current through the heating element includes continuously measuring the current through the heating element without interrupting power to the heating element.

29. The method of any one of claims 19 to 28, wherein, measuring the voltage across the heating element includes continuously measuring the voltage across the heating element without interrupting power to the heating element.

30. The method of any one of claims 19 to 29, wherein, the power source is a battery.

31. The method of any one of claims 19-30, further comprising: measuring a power source output voltage; and selecting an operating circuit for powering the heating element, wherein when the power source output voltage is greater than or equal to 4.0 V, the operating circuit is a pulse width modulation control circuit, and wherein when the power source output voltage is less than 4.0 V, the operating circuit is a DC-DC converter control circuit including a DC-DC converter.

32. The method of any one of claims 19-30, further comprising: measuring a power source output voltage; and selecting an operating circuit for powering the heating element, wherein when the power source output voltage is greater than or equal to 3.8 V, the operating circuit is a pulse width modulation control circuit, and wherein when the power source output voltage is less than 3.8 V, the operating circuit is a DC-DC converter control circuit including a DC-DC converter.

33. The method of any one of claims 19-30, further comprising: measuring a power source output voltage; and selecting an operating circuit for powering the heating element, wherein when the power source output voltage is greater than or equal to 3.6 V, the operating circuit is a pulse width modulation control circuit, and wherein when the power source output voltage is less than 3.6 V, the operating circuit is a DC-DC converter control circuit including a DC-DC converter.

34. The method of any one of claims 19-30, further comprising: measuring a power source output voltage; and selecting an operating circuit for powering the heating element, wherein when the power source output voltage is greater than or equal to 3.4 V, the operating circuit is a pulse width modulation control circuit, and wherein when the power source output voltage is less than 3.4 V, the operating circuit is a DC-DC converter control circuit including a DC-DC converter.

35. The method of any one of claims 19-30, further comprising: measuring a duty cycle of the pulse width modulation control circuit; and selecting a DC-DC converter control circuit comprising a DC-DC converter when the duty cycle is greater than 85%.

36. The method of any one of claims 19-30, further comprising: measuring a duty cycle of the pulse width modulation control circuit; and selecting a DC-DC converter control circuit comprising a DC-DC converter when the duty cycle is greater than 90%.

37. The method of any one of claims 19-30, further comprising: measuring a duty cycle of the pulse width modulation control circuit; and selecting a DC-DC converter control circuit comprising a DC-DC converter when the duty cycle is greater than 95%.

38. The method of any one of claims 19-30, further comprising: measuring a duty cycle of the pulse width modulation control circuit; and selecting a DC-DC converter control circuit comprising a DC-DC converter when the duty cycle is greater than 98%.

39. The method of any one of claims 19-30, further comprising: measuring a duty cycle of the pulse width modulation control circuit; and selecting a DC-DC converter control circuit comprising a DC-DC converter when the duty cycle is 100%.

40. The method of claim 19, wherein, measuring the voltage across the heating element comprises using a 3-wire or 4-wire connection to measure the voltage across the heating element.

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