Patent Publication Number: US-11653704-B2

Title: Heating engine control circuits and nicotine electronic vaping devices including the same

Description:
BACKGROUND 
     Field 
     One or more example embodiments relate to nicotine electronic vaping (nicotine e-vaping) devices. 
     Description of Related Art 
     Nicotine electronic vaping devices (or nicotine e-vaping devices) include a heater that vaporizes nicotine pre-vapor formulation material to produce nicotine vapor. A nicotine e-vaping device may include several e-vaping elements including a power source, a cartridge or e-vaping tank including the heater and a nicotine reservoir capable of holding the nicotine pre-vapor formulation material. 
     SUMMARY 
     At least one example embodiment provides a heating engine control circuit to control operation of a heater of a nicotine electronic vaping device, the heating engine control circuit including: a rail converter circuit configured to convert a power supply voltage into a power signal based on a vaping enable signal, the vaping enable signal being a pulse width modulated signal; and a gate driver circuit including an integrated gate driver, the integrated gate driver configured to control application of power to the heater to heat nicotine pre-vapor formulation drawn from a nicotine reservoir at the nicotine electronic vaping device based on the power signal, a first enable signal and a second enable signal. 
     At least one other example embodiment provides a nicotine electronic vaping device including: a heater configured to heat nicotine pre-vapor formulation drawn from a nicotine reservoir; a rail converter circuit configured to convert a power supply voltage into a power signal based on a vaping enable signal, the vaping enable signal being a pulse width modulated signal; and a gate driver circuit including an integrated gate driver, the integrated gate driver configured to control application of power to the heater of the nicotine electronic vaping device based on the power signal, a first enable signal and a second enable signal. 
     According to one or more example embodiments, the rail converter circuit may be configured to disable the power signal in response to termination of the vaping enable signal. 
     The rail converter circuit may be configured to output a feedback signal, wherein the feedback signal is a scaled version of the power signal indicating a current voltage level of the power signal. The nicotine electronic vaping device may include a controller configured to generate the vaping enable signal based on the feedback signal. The controller may be configured to control a duty cycle of the vaping enable signal based on the feedback signal. 
     The second enable signal may be a pulse width modulated signal, the integrated gate driver may be configured to receive the second enable signal at an input pin, and the gate driver circuit may include a filter circuit connected to the input pin, the filter circuit configured to filter the second enable signal prior to input to the integrated gate driver. 
     The gate driver circuit may include a pulldown resistor connected to the input pin of the integrated gate driver, wherein the pulldown resistor is configured to maintain the input pin at a logic low level when the second enable signal is in a floating state. 
     The gate driver circuit may include a boot-strap charge-pump circuit connected between an input voltage pin and a boost pin of the integrated gate driver. The boot-strap charge-pump circuit may be connected to a switching node pin of the integrated gate driver. 
     The gate driver circuit may include a filter circuit connected between an input terminal of the power signal and the boot-strap charge-pump circuit. 
     The rail converter circuit may include: a first capacitor connected between a power supply and ground; an inductor having a first terminal connected to a first node between the power supply and the first capacitor, and a second terminal connected to a second node; a switching transistor connected between the second node and ground, the switching transistor configured to receive the vaping enable signal; a second capacitor having a first terminal connected to the second node, and a second terminal connected to a third node; a first diode having an anode connected to ground and a cathode connected to the third node; a second diode having an anode connected to the third node, and a cathode connected to a fourth node; a third capacitor connected between the fourth node and ground; and a voltage divider circuit connected to the fourth node, the voltage divider circuit configured to output a feedback signal based on the power signal. 
     The rail converter circuit further may include a pull-down resistor connected between a gate of the switching transistor and ground, wherein the pull-down resistor is configured to prevent output of the power signal when the vaping enable signal has an indeterminate state. 
     The gate driver circuit further may include: a first filter circuit configured to filter the power signal for input to the integrated gate driver; and a second filter circuit configured to filter the second enable signal for input to the integrated gate driver. 
     The heating engine control circuit and/or the nicotine electronic vaping device may include a heating engine drive circuit configured to control power to the heater, wherein the heating engine drive circuit includes a first transistor and a second transistor connected in series between a power supply and ground. The gate driver circuit may be configured to output a driving voltage to a gate of the first transistor to maintain a gate-source voltage of the first transistor at a voltage level of the power signal independent of a voltage level of the power supply. 
     The heating engine control circuit and/or the nicotine electronic vaping device may include a heating engine drive circuit configured to control power to the heater, wherein the heating engine drive circuit includes a first transistor and a second transistor connected in series between a power supply and ground. The gate driver circuit may be configured to output a current switched signal to generate a voltage output to the heater, a level of the voltage output to the heater being independent of a voltage level of the power supply. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For purposes of clarity, various dimensions of the drawings may have been exaggerated. 
         FIG.  1    is a front view of a nicotine e-vaping device according to an example embodiment. 
         FIG.  2    is a side view of the nicotine e-vaping device of  FIG.  1   . 
         FIG.  3    is a rear view of the nicotine e-vaping device of  FIG.  1   . 
         FIG.  4    is a proximal end view of the nicotine e-vaping device of  FIG.  1   . 
         FIG.  5    is a distal end view of the nicotine e-vaping device of  FIG.  1   . 
         FIG.  6    is a perspective view of the nicotine e-vaping device of  FIG.  1   . 
         FIG.  7    is an enlarged view of the pod inlet in  FIG.  6   . 
         FIG.  8    is a cross-sectional view of the nicotine e-vaping device of  FIG.  6   . 
         FIG.  9    is a perspective view of the device body of the nicotine e-vaping device of  FIG.  6   . 
         FIG.  10    is a front view of the device body of  FIG.  9   . 
         FIG.  11    is an enlarged perspective view of the through hole in  FIG.  10   . 
         FIG.  12    is an enlarged perspective view of the device electrical contacts in  FIG.  10   . 
         FIG.  13    is a partially exploded view involving the mouthpiece in  FIG.  12   . 
         FIG.  14    is a partially exploded view involving the bezel structure in  FIG.  9   . 
         FIG.  15    is an enlarged perspective view of the mouthpiece, springs, retention structure, and bezel structure in  FIG.  14   . 
         FIG.  16    is a partially exploded view involving the front cover, the frame, and the rear cover in  FIG.  14   . 
         FIG.  17    is a perspective view of the nicotine pod assembly of the nicotine e-vaping device in  FIG.  6   . 
         FIG.  18    is another perspective view of the nicotine pod assembly of  FIG.  17   . 
         FIG.  19    is another perspective view of the nicotine pod assembly of  FIG.  18   . 
         FIG.  20    is a perspective view of the nicotine pod assembly of  FIG.  19    without the connector module. 
         FIG.  21    is a perspective view of the connector module in  FIG.  19   . 
         FIG.  22    is another perspective view of the connector module of  FIG.  21   . 
         FIG.  23    is an exploded view involving the wick, heater, electrical leads, and contact core in  FIG.  22   . 
         FIG.  24    is an exploded view involving the first housing section of the nicotine pod assembly of  FIG.  17   . 
         FIG.  25    is a partially exploded view involving the second housing section of the nicotine pod assembly of  FIG.  17   . 
         FIG.  26    is an exploded view of the activation pin in  FIG.  25   . 
         FIG.  27    is a perspective view of the connector module of  FIG.  22    without the wick, heater, electrical leads, and contact core. 
         FIG.  28    is an exploded view of the connector module of  FIG.  27   . 
         FIG.  29    illustrates electrical systems of a device body and a nicotine pod assembly of a nicotine e-vaping device according to one or more example embodiments. 
         FIG.  30    is a simple block diagram illustrating a dry puff and auto shutdown control system according to example embodiments. 
         FIG.  31    is a flow chart illustrating a dryness detection method according to example embodiments. 
         FIG.  32    illustrates graphs of resistance versus time when dry puff conditions exist at the start of a puff (‘Dry Puff’), when dry puff conditions occur during a puff (‘Drying Puff’), and when dry puff conditions are not present (‘Standard Puff’). 
         FIG.  33    is a flow chart illustrating an example method of operation of a nicotine e-vaping device after shutdown of the vaping function in response to detecting a hard fault pod event, such as dry puff conditions, according to example embodiments. 
         FIG.  34    illustrates a heater voltage measurement circuit according to example embodiments. 
         FIG.  35    illustrates a heater current measurement circuit according to example embodiments. 
         FIG.  36    illustrates a pod temperature measurement circuit according to some example embodiments. 
         FIG.  37    illustrates a pod temperature measurement circuit according to some other example embodiments. 
         FIG.  38    is a circuit diagram illustrating a heating engine control circuit according to some example embodiments. 
         FIG.  39    is a circuit diagram illustrating a heating engine control circuit according to some other example embodiments. 
         FIG.  40    illustrates a temperature sensing transducer according to some example embodiments. 
         FIG.  41    illustrates a temperature sensing transducer according to some other example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Some detailed example embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. Example embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein. 
     Accordingly, while example embodiments are capable of various modifications and alternative forms, example embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but to the contrary, example embodiments are to cover all modifications, equivalents, and alternatives thereof. Like numbers refer to like elements throughout the description of the figures. 
     It should be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” “attached to,” “adjacent to,” or “covering” another element or layer, it may be directly on, connected to, coupled to, attached to, adjacent to or covering the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term “and/or” includes any and all combinations or sub-combinations of one or more of the associated listed items. 
     It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, regions, layers and/or sections, these elements, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, region, layer, or section from another region, layer, or section. Thus, a first element, region, layer, or section discussed below could be termed a second element, region, layer, or section without departing from the teachings of example embodiments. 
     Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like) may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing various example embodiments only and is not intended to be limiting of example embodiments. 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. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations and/or elements but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or groups thereof. 
     When the words “about” and “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value, unless otherwise explicitly defined. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     A “nicotine electronic vaping device” or “nicotine e-vaping device” as used herein may be referred to on occasion using, and considered synonymous with, nicotine e-vapor apparatus and/or nicotine e-vaping apparatus. 
       FIG.  1    is a front view of a nicotine e-vaping device according to an example embodiment.  FIG.  2    is a side view of the nicotine e-vaping device of  FIG.  1   .  FIG.  3    is a rear view of the nicotine e-vaping device of  FIG.  1   . Referring to  FIGS.  1 - 3   , a nicotine e-vaping device  500  includes a device body  100  that is configured to receive a nicotine pod assembly  300 . The nicotine pod assembly  300  is a modular article configured to hold a nicotine pre-vapor formulation. A “nicotine pre-vapor formulation” is a material or combination of materials that may be transformed into a vapor. For example, the nicotine pre-vapor formulation may be a liquid, solid, and/or gel formulation including, but not limited to, water, beads, solvents, active ingredients, ethanol, plant extracts, natural or artificial flavors, and/or nicotine vapor formers such as glycerin and propylene glycol. During vaping, the nicotine e-vaping device  500  is configured to heat the nicotine pre-vapor formulation to generate a vapor. As referred to herein, a “nicotine vapor” is any matter generated or outputted from any nicotine e-vaping device according to any of the example embodiments disclosed herein. 
     As shown in  FIGS.  1  and  3   , the nicotine e-vaping device  500  extends in a longitudinal direction and has a length that is greater than its width. In addition, as shown in  FIG.  2   , the length of the nicotine e-vaping device  500  is also greater than its thickness. Furthermore, the width of the nicotine e-vaping device  500  may be greater than its thickness. Assuming an x-y-z Cartesian coordinate system, the length of the nicotine e-vaping device  500  may be measured in the y-direction, the width may be measured in the x-direction, and the thickness may be measured in the z-direction. The nicotine e-vaping device  500  may have a substantially linear form with tapered ends based on its front, side, and rear views, although example embodiments are not limited thereto. 
     The device body  100  includes a front cover  104 , a frame  106 , and a rear cover  108 . The front cover  104 , the frame  106 , and the rear cover  108  form a device housing that encloses mechanical elements, electronic elements, and/or circuitry associated with the operation of the nicotine e-vaping device  500 . For instance, the device housing of the device body  100  may enclose a power source configured to power the nicotine e-vaping device  500 , which may include supplying an electric current to the nicotine pod assembly  300 . The device housing of the device body  100  may also include one or more electrical systems to control the nicotine e-vaping device  500 . Electrical systems according to example embodiments will be discussed in more detail later. In addition, when assembled, the front cover  104 , the frame  106 , and the rear cover  108  may constitute a majority of the visible portion of the device body  100 . 
     The front cover  104  (e.g., first cover) defines a primary opening configured to accommodate a bezel structure  112 . The primary opening may have a rounded rectangular shape, although other shapes are possible depending on the shape of the bezel structure  112 . The bezel structure  112  defines a through hole  150  configured to receive the nicotine pod assembly  300 . The through hole  150  is discussed herein in more detail in connection with, for instance,  FIG.  9   . 
     The front cover  104  also defines a secondary opening configured to accommodate a light guide arrangement. The secondary opening may resemble a slot (e.g., elongated rectangle with rounded edges), although other shapes are possible depending on the shape of the light guide arrangement. In an example embodiment, the light guide arrangement includes a light guide housing  114  and a button housing  122 . The light guide housing  114  is configured to expose a light guide lens  116 , while the button housing  122  is configured to expose a first button lens  124  and a second button lens  126  (e.g.,  FIG.  16   ). The first button lens  124  and an upstream portion of the button housing  122  may form a first button  118 . Similarly, the second button lens  126  and a downstream portion of the button housing  122  may form a second button  120 . The button housing  122  may be in a form of a single structure or two separate structures. With the latter form, the first button  118  and the second button  120  can move with a more independent feel when pressed. 
     The operation of the nicotine e-vaping device  500  may be controlled by the first button  118  and the second button  120 . For instance, the first button  118  may be a power button, and the second button  120  may be an intensity button. Although two buttons are shown in the drawings in connection with the light guide arrangement, it should be understood that more (or less) buttons may be provided depending on the available features and desired user interface. 
     The frame  106  (e.g., base frame) is the central support structure for the device body  100  (and the nicotine e-vaping device  500  as a whole). The frame  106  may be referred to as a chassis. The frame  106  includes a proximal end, a distal end, and a pair of side sections between the proximal end and the distal end. The proximal end and the distal end may also be referred to as the downstream end and the upstream end, respectively. As used herein, “proximal” (and, conversely, “distal”) is in relation to an adult vaper during vaping, and “downstream” (and, conversely, “upstream”) is in relation to a flow of the vapor. A bridging section may be provided between the opposing inner surfaces of the side sections (e.g., about midway along the length of the frame  106 ) for additional strength and stability. The frame  106  may be integrally formed so as to be a monolithic structure. 
     With regard to material of construction, the frame  106  may be formed of an alloy or a plastic. The alloy (e.g., die cast grade, machinable grade) may be an aluminum (Al) alloy or a zinc (Zn) alloy. The plastic may be a polycarbonate (PC), an acrylonitrile butadiene styrene (ABS), or a combination thereof (PC/ABS). For instance, the polycarbonate may be LUPOY SC1004A. Furthermore, the frame  106  may be provided with a surface finish for functional and/or aesthetic reasons (e.g., to provide a premium appearance). In an example embodiment, the frame  106  (e.g., when formed of an aluminum alloy) may be anodized. In another embodiment, the frame  106  (e.g., when formed of a zinc alloy) may be coated with a hard enamel or painted. In another embodiment, the frame  106  (e.g., when formed of a polycarbonate) may be metallized. In yet another embodiment, the frame  106  (e.g., when formed of an acrylonitrile butadiene styrene) may be electroplated. It should be understood that the materials of construction with regard to the frame  106  may also be applicable to the front cover  104 , the rear cover  108 , and/or other appropriate parts of the nicotine e-vaping device  500 . 
     The rear cover  108  (e.g., second cover) also defines an opening configured to accommodate the bezel structure  112 . The opening may have a rounded rectangular shape, although other shapes are possible depending on the shape of the bezel structure  112 . In an example embodiment, the opening in the rear cover  108  is smaller than the primary opening in the front cover  104 . In addition, although not shown, it should be understood that a light guide arrangement (e.g., including buttons) may be provided on the rear of the nicotine e-vaping device  500  in addition to (or in lieu of) the light guide arrangement on the front of the nicotine e-vaping device  500 . 
     The front cover  104  and the rear cover  108  may be configured to engage with the frame  106  via a snap-fit arrangement. For instance, the front cover  104  and/or the rear cover  108  may include clips configured to interlock with corresponding mating members of the frame  106 . In a non-limiting embodiment, the clips may be in a form of tabs with orifices configured to receive the corresponding mating members (e.g., protrusions with beveled edges) of the frame  106 . Alternatively, the front cover  104  and/or the rear cover  108  may be configured to engage with the frame  106  via an interference fit (which may also be referred to as a press fit or friction fit). However, it should be understood that the front cover  104 , the frame  106 , and the rear cover  108  may be coupled via other suitable arrangements and techniques. 
     The device body  100  also includes a mouthpiece  102 . The mouthpiece  102  may be secured to the proximal end of the frame  106 . Additionally, as shown in  FIG.  2   , in an example embodiment where the frame  106  is sandwiched between the front cover  104  and the rear cover  108 , the mouthpiece  102  may abut the front cover  104 , the frame  106 , and the rear cover  108 . Furthermore, in a non-limiting embodiment, the mouthpiece  102  may be joined with the device housing via a bayonet connection. 
       FIG.  4    is a proximal end view of the nicotine e-vaping device of  FIG.  1   . Referring to  FIG.  4   , the outlet face of the mouthpiece  102  defines a plurality of vapor outlets. In a non-limiting embodiment, the outlet face of the mouthpiece  102  may be elliptically-shaped. In addition, the outlet face of the mouthpiece  102  may include a first crossbar corresponding to a major axis of the elliptically-shaped outlet face and a second crossbar corresponding to a minor axis of the elliptically-shaped outlet face. Furthermore, the first crossbar and the second crossbar may intersect perpendicularly and be integrally formed parts of the mouthpiece  102 . Although the outlet face is shown as defining four vapor outlets, it should be understood that example embodiments are not limited thereto. For instance, the outlet face may define less than four (e.g., one, two) vapor outlets or more than four (e.g., six, eight) vapor outlets. 
       FIG.  5    is a distal end view of the nicotine e-vaping device of  FIG.  1   . Referring to  FIG.  5   , the distal end of the nicotine e-vaping device  500  includes a port  110 . The port  110  is configured to receive an electric current (e.g., via a USB cable) from an external power source so as to charge an internal power source within the nicotine e-vaping device  500 . In addition, the port  110  may also be configured to send data to and/or receive data (e.g., via a USB cable) from another nicotine e-vaping device or other electronic device (e.g., phone, tablet, computer). Furthermore, the nicotine e-vaping device  500  may be configured for wireless communication with another electronic device, such as a phone, via an application software (app) installed on that electronic device. In such an instance, an adult vaper may control or otherwise interface with the nicotine e-vaping device  500  (e.g., locate the nicotine e-vaping device, check usage information, change operating parameters) through the app. 
       FIG.  6    is a perspective view of the nicotine e-vaping device of  FIG.  1   .  FIG.  7    is an enlarged view of the pod inlet in  FIG.  6   . Referring to  FIGS.  6 - 7   , and as briefly noted above, the nicotine e-vaping device  500  includes a nicotine pod assembly  300  configured to hold a nicotine pre-vapor formulation. The nicotine pod assembly  300  has an upstream end (which faces the light guide arrangement) and a downstream end (which faces the mouthpiece  102 ). In a non-limiting embodiment, the upstream end is an opposing surface of the nicotine pod assembly  300  from the downstream end. The upstream end of the nicotine pod assembly  300  defines a pod inlet  322 . The device body  100  defines a through hole (e.g., through hole  150  in  FIG.  9   ) configured to receive the nicotine pod assembly  300 . In an example embodiment, the bezel structure  112  of the device body  100  defines the through hole and includes an upstream rim. As shown, particularly in  FIG.  7   , the upstream rim of the bezel structure  112  is angled (e.g., dips inward) so as to expose the pod inlet  322  when the nicotine pod assembly  300  is seated within the through hole of the device body  100 . 
     For instance, rather than following the contour of the front cover  104  (so as to be relatively flush with the front face of the nicotine pod assembly  300  and, thus, obscure the pod inlet  322 ), the upstream rim of the bezel structure  112  is in a form of a scoop configured to direct ambient air into the pod inlet  322 . This angled/scoop configuration may help reduce or prevent the blockage of the air inlet (e.g., pod inlet  322 ) of the nicotine e-vaping device  500 . The depth of the scoop may be such that less than half (e.g., less than a quarter) of the upstream end face of the nicotine pod assembly  300  is exposed. Additionally, in a non-limiting embodiment, the pod inlet  322  is in a form of a slot. Furthermore, if the device body  100  is regarded as extending in a first direction, then the slot may be regarded as extending in a second direction, wherein the second direction is transverse to the first direction. 
       FIG.  8    is a cross-sectional view of the nicotine e-vaping device of  FIG.  6   . In  FIG.  8   , the cross-section is taken along the longitudinal axis of the nicotine e-vaping device  500 . As shown, the device body  100  and the nicotine pod assembly  300  include mechanical elements, electronic elements, and/or circuitry associated with the operation of the nicotine e-vaping device  500 , which are discussed in more detail herein and/or are incorporated by reference herein. For instance, the nicotine pod assembly  300  may include mechanical elements configured to actuate to release the nicotine pre-vapor formulation from a sealed nicotine reservoir within. The nicotine pod assembly  300  may also have mechanical aspects configured to engage with the device body  100  to facilitate the insertion and seating of the nicotine pod assembly  300 . 
     Additionally, the nicotine pod assembly  300  may be a “smart pod” that includes electronic elements and/or circuitry configured to store, receive, and/or transmit information to/from the device body  100 . Such information may be used to authenticate the nicotine pod assembly  300  for use with the device body  100  (e.g., to prevent usage of an unapproved/counterfeit nicotine pod assembly). Furthermore, the information may be used to identify a type of the nicotine pod assembly  300  which is then correlated with a vaping profile based on the identified type. The vaping profile may be designed to set forth the general parameters for the heating of the nicotine pre-vapor formulation and may be subject to tuning, refining, or other adjustment by an adult vaper before and/or during vaping. 
     The nicotine pod assembly  300  may also communicate with the device body  100  other information that may be relevant to the operation of the nicotine e-vaping device  500 . Examples of relevant information may include a level of the nicotine pre-vapor formulation within the nicotine pod assembly  300  and/or a length of time that has passed since the nicotine pod assembly  300  was inserted into the device body  100  and activated. For instance, if the nicotine pod assembly  300  was inserted into the device body  100  and activated more than a certain period of time prior (e.g., more than 6 months ago), the nicotine e-vaping device  500  may not permit vaping, and the adult vaper may be prompted to change to a new nicotine pod assembly even though the nicotine pod assembly  300  still contains adequate levels of nicotine pre-vapor formulation. 
     The device body  100  may include mechanical elements (e.g. complementary structures) configured to engage, hold, and/or activate the nicotine pod assembly  300 . In addition, the device body  100  may include electronic elements and/or circuitry configured to receive an electric current to charge an internal power source (e.g., battery) which, in turn, is configured to supply power to the nicotine pod assembly  300  during vaping. Furthermore, the device body  100  may include electronic elements and/or circuitry configured to communicate with the nicotine pod assembly  300 , a different nicotine e-vaping device, other electronic devices (e.g., phone, tablet, computer), and/or the adult vaper. The information being communicated may include pod-specific data, current vaping details, and/or past vaping patterns/history. The adult vaper may be notified of such communications with feedback that is haptic (e.g., vibrations), auditory (e.g., beeps), and/or visual (e.g., colored/blinking lights). The charging and/or communication of information may be performed with the port  110  (e.g., via a USB cable). 
       FIG.  9    is a perspective view of the device body of the nicotine e-vaping device of  FIG.  6   . Referring to  FIG.  9   , the bezel structure  112  of the device body  100  defines a through hole  150 . The through hole  150  is configured to receive a nicotine pod assembly  300 . To facilitate the insertion and seating of the nicotine pod assembly  300  within the through hole  150 , the upstream rim of the bezel structure  112  includes a first upstream protrusion  128   a  and a second upstream protrusion  128   b . The through hole  150  may have a rectangular shape with rounded corners. In an example embodiment, the first upstream protrusion  128   a  and the second upstream protrusion  128   b  are integrally formed with the bezel structure  112  and located at the two rounded corners of the upstream rim. 
     The downstream sidewall of the bezel structure  112  may define a first downstream opening, a second downstream opening, and a third downstream opening. A retention structure including a first downstream protrusion  130   a  and a second downstream protrusion  130   b  is engaged with the bezel structure  112  such that the first downstream protrusion  130   a  and the second downstream protrusion  130   b  protrude through the first downstream opening and the second downstream opening, respectively, of the bezel structure  112  and into the through hole  150 . In addition, a distal end of the mouthpiece  102  extends through the third downstream opening of the bezel structure  112  and into the through hole  150  so as to be between the first downstream protrusion  130   a  and the second downstream protrusion  130   b.    
       FIG.  10    is a front view of the device body of  FIG.  9   . Referring to  FIG.  10   , the device body  100  includes a device electrical connector  132  disposed at an upstream side of the through hole  150 . The device electrical connector  132  of the device body  100  is configured to electrically engage with a nicotine pod assembly  300  that is seated within the through hole  150 . As a result, power can be supplied from the device body  100  to the nicotine pod assembly  300  via the device electrical connector  132  during vaping. In addition, data can be sent to and/or received from the device body  100  and the nicotine pod assembly  300  via the device electrical connector  132 . 
       FIG.  11    is an enlarged perspective view of the through hole in  FIG.  10   . Referring to  FIG.  11   , the first upstream protrusion  128   a , the second upstream protrusion  128   b , the first downstream protrusion  130   a , the second downstream protrusion  130   b , and the distal end of the mouthpiece  102  protrude into the through hole  150 . In an example embodiment, the first upstream protrusion  128   a  and the second upstream protrusion  128   b  are stationary structures (e.g., stationary pivots), while the first downstream protrusion  130   a  and the second downstream protrusion  130   b  are tractable structures (e.g., retractable members). For instance, the first downstream protrusion  130   a  and the second downstream protrusion  130   b  may be configured (e.g., spring-loaded) to default to a protracted state while also configured to transition temporarily to a retracted state (and reversibly back to the protracted state) to facilitate an insertion of a nicotine pod assembly  300 . 
     In particular, when inserting a nicotine pod assembly  300  into the through hole  150  of the device body  100 , recesses at the upstream end face of the nicotine pod assembly  300  may be initially engaged with the first upstream protrusion  128   a  and the second upstream protrusion  128   b  followed by a pivoting of the nicotine pod assembly  300  (about the first upstream protrusion  128   a  and the second upstream protrusion  128   b ) until recesses at the downstream end face of the nicotine pod assembly  300  are engaged with the first downstream protrusion  130   a  and the second downstream protrusion  130   b . In such an instance, the axis of rotation (during pivoting) of the nicotine pod assembly  300  may be orthogonal to the longitudinal axis of the device body  100 . In addition, the first downstream protrusion  130   a  and the second downstream protrusion  130   b , which may be biased so as to be tractable, may retract when the nicotine pod assembly  300  is being pivoted into the through hole  150  and resiliently protract to engage recesses at the downstream end face of the nicotine pod assembly  300 . Furthermore, the engagement of the first downstream protrusion  130   a  and the second downstream protrusion  130   b  with recesses at the downstream end face of the nicotine pod assembly  300  may produce a haptic and/or auditory feedback (e.g., audible click) to notify an adult vaper that the nicotine pod assembly  300  is properly seated in the through hole  150  of the device body  100 . 
       FIG.  12    is an enlarged perspective view of the device electrical contacts in  FIG.  10   . The device electrical contacts of the device body  100  are configured to engage with the pod electrical contacts of the nicotine pod assembly  300  when the nicotine pod assembly  300  is seated within the through hole  150  of the device body  100 . Referring to  FIG.  12   , the device electrical contacts of the device body  100  include the device electrical connector  132 . The device electrical connector  132  includes power contacts and data contacts. The power contacts of the device electrical connector  132  are configured to supply power from the device body  100  to the nicotine pod assembly  300 . As illustrated, the power contacts of the device electrical connector  132  include a first pair of power contacts and a second pair of power contacts (which are positioned so as to be closer to the front cover  104  than the rear cover  108 ). The first pair of power contacts (e.g., the pair adjacent to the first upstream protrusion  128   a ) may be a single integral structure that is distinct from the second pair of power contacts and that, when assembled, includes two projections that extend into the through hole  150 . Similarly, the second pair of power contacts (e.g., the pair adjacent to the second upstream protrusion  128   b ) may be a single integral structure that is distinct from the first pair of power contacts and that, when assembled, includes two projections that extend into the through hole  150 . The first pair of power contacts and the second pair of power contacts of the device electrical connector  132  may be tractably-mounted and biased so as to protract into the through hole  150  as a default and to retract (e.g., independently) from the through hole  150  when subjected to a force that overcomes the bias. 
     The data contacts of the device electrical connector  132  are configured to transmit data between a nicotine pod assembly  300  and the device body  100 . As illustrated, the data contacts of the device electrical connector  132  include a row of five projections (which are positioned so as to be closer to the rear cover  108  than the front cover  104 ). The data contacts of the device electrical connector  132  may be distinct structures that, when assembled, extend into the through hole  150 . The data contacts of the device electrical connector  132  may also be tractably-mounted and biased (e.g., with springs) so as to protract into the through hole  150  as a default and to retract (e.g., independently) from the through hole  150  when subjected to a force that overcomes the bias. For instance, when a nicotine pod assembly  300  is inserted into the through hole  150  of the device body  100 , the pod electrical contacts of the nicotine pod assembly  300  will press against the corresponding device electrical contacts of the device body  100 . As a result, the power contacts and the data contacts of the device electrical connector  132  will be retracted (e.g., at least partially retracted) into the device body  100  but will continue to push against the corresponding pod electrical contacts due to their resilient arrangement, thereby helping to ensure a proper electrical connection between the device body  100  and the nicotine pod assembly  300 . Furthermore, such a connection may also be mechanically secure and have minimal contact resistance so as to allow power and/or signals between the device body  100  and the nicotine pod assembly  300  to be transferred and/or communicated reliably and accurately. While various aspects have been discussed in connection with the device electrical contacts of the device body  100 , it should be understood that example embodiments are not limited thereto and that other configurations may be utilized. 
       FIG.  13    is a partially exploded view involving the mouthpiece in  FIG.  12   . Referring to  FIG.  13   , the mouthpiece  102  is configured to engage with the device housing via a retention structure  140 . In an example embodiment, the retention structure  140  is situated so as to be primarily between the frame  106  and the bezel structure  112 . As shown, the retention structure  140  is disposed within the device housing such that the proximal end of the retention structure  140  extends through the proximal end of the frame  106 . The retention structure  140  may extend slightly beyond the proximal end of the frame  106  or be substantially even therewith. The proximal end of the retention structure  140  is configured to receive a distal end of the mouthpiece  102 . The proximal end of the retention structure  140  may be a female end, while the distal end of the mouthpiece may be a male end. 
     For instance, the mouthpiece  102  may be coupled (e.g., reversibly coupled) to the retention structure  140  with a bayonet connection. In such an instance, the female end of the retention structure  140  may define a pair of opposing L-shaped slots, while the male end of the mouthpiece  102  may have opposing radial members  134  (e.g., radial pins) configured to engage with the L-shaped slots of the retention structure  140 . Each of the L-shaped slots of the retention structure  140  have a longitudinal portion and a circumferential portion. Optionally, the terminus of the circumferential portion may have a serif portion to help reduce or prevent the likelihood that that a radial member  134  of the mouthpiece  102  will inadvertently become disengaged. In a non-limiting embodiment, the longitudinal portions of the L-shaped slots extend in parallel and along a longitudinal axis of the device body  100 , while the circumferential portions of the L-shaped slots extend around the longitudinal axis (e.g., central axis) of the device body  100 . As a result, to couple the mouthpiece  102  to the device housing, the mouthpiece  102  shown in  FIG.  13    is initially rotated 90 degrees to align the radial members  134  with the entrances to the longitudinal portions of the L-shaped slots of the retention structure  140 . The mouthpiece  102  is then pushed into the retention structure  140  such that the radial members  134  slide along the longitudinal portions of the L-shaped slots until the junction with each of the circumferential portions is reached. At this point, the mouthpiece  102  is then rotated such that the radial members  134  travel across the circumferential portions until the terminus of each is reached. Where a serif portion is present at each terminus, a haptic and/or auditory feedback (e.g., audible click) may be produced to notify an adult vaper that the mouthpiece  102  has been properly coupled to the device housing. 
     The mouthpiece  102  defines a vapor passage  136  through which nicotine vapor flows during vaping. The vapor passage  136  is in fluidic communication with the through hole  150  (which is where the nicotine pod assembly  300  is seated within the device body  100 ). The proximal end of the vapor passage  136  may include a flared portion. In addition, the mouthpiece  102  may include an end cover  138 . The end cover  138  may taper from its distal end to its proximal end. The outlet face of the end cover  138  defines a plurality of vapor outlets. Although four vapor outlets are shown in the end cover  138 , it should be understood that example embodiments are not limited thereto. 
       FIG.  14    is a partially exploded view involving the bezel structure in  FIG.  9   .  FIG.  15    is an enlarged perspective view of the mouthpiece, springs, retention structure, and bezel structure in  FIG.  14   . Referring to  FIGS.  14 - 15   , the bezel structure  112  includes an upstream sidewall and a downstream sidewall. The upstream sidewall of the bezel structure  112  defines a connector opening  146 . The connector opening  146  is configured to expose or receive the device electrical connector  132  of the device body  100 . The downstream sidewall of the bezel structure  112  defines a first downstream opening  148   a , a second downstream opening  148   b , and a third downstream opening  148   c . The first downstream opening  148   a  and the second downstream opening  148   b  of the bezel structure  112  are configured to receive the first downstream protrusion  130   a  and the second downstream protrusion  130   b , respectively, of the retention structure  140 . The third downstream opening  148   c  of the bezel structure  112  is configured to receive the distal end of the mouthpiece  102 . 
     As shown in  FIG.  14   , the first downstream protrusion  130   a  and the second downstream protrusion  130   b  are on the concave side of the retention structure  140 . As shown in  FIG.  15   , a first post  142   a  and a second post  142   b  are on the opposing convex side of the retention structure  140 . A first spring  144   a  and a second spring  144   b  are disposed on the first post  142   a  and the second post  142   b , respectively. The first spring  144   a  and the second spring  144   b  are configured to bias the retention structure  140  against the bezel structure  112 . 
     When assembled, the bezel structure  112  may be secured to the frame  106  via a pair of tabs adjacent to the connector opening  146 . In addition, the retention structure  140  will abut the bezel structure  112  such that the first downstream protrusion  130   a  and the second downstream protrusion  130   b  extend through the first downstream opening  148   a  and the second downstream opening  148   b , respectively. The mouthpiece  102  will be coupled to the retention structure  140  such that the distal end of the mouthpiece  102  extends through the retention structure  140  as well as the third downstream opening  148   c  of the bezel structure  112 . The first spring  144   a  and the second spring  144   b  will be between the frame  106  and the retention structure  140 . 
     When a nicotine pod assembly  300  is being inserted into the through hole  150  of the device body  100 , the downstream end of the nicotine pod assembly  300  will push against the first downstream protrusion  130   a  and the second downstream protrusion  130   b  of the retention structure  140 . As a result, the first downstream protrusion  130   a  and the second downstream protrusion  130   b  of the retention structure  140  will resiliently yield and retract from the through hole  150  of the device body  100  (by virtue of compression of the first spring  144   a  and the second spring  144   b ), thereby allowing the insertion of the nicotine pod assembly  300  to proceed. In an example embodiment, when the first downstream protrusion  130   a  and the second downstream protrusion  130   b  are fully retracted from the through hole  150  of the device body  100 , the displacement of the retention structure  140  may cause the ends of the first post  142   a  and the second post  142   b  to contact the inner end surface of the frame  106 . Furthermore, because the mouthpiece  102  is coupled to the retention structure  140 , the distal end of the mouthpiece  102  will retract from the through hole  150 , thus causing the proximal end of the mouthpiece  102  (e.g., visible portion including the end cover  138 ) to also shift by a corresponding distance away from the device housing. 
     Once the nicotine pod assembly  300  is adequately inserted such that the first downstream recess and the second downstream recess of the nicotine pod assembly  300  reach a position that allows an engagement with the first downstream protrusion  130   a  and the second downstream protrusion  130   b , respectively, the stored energy from the compression of the first spring  144   a  and the second spring  144   b  will cause the first downstream protrusion  130   a  and the second downstream protrusion  130   b  to resiliently protract and engage with the first downstream recess and the second downstream recess, respectively, of the nicotine pod assembly  300 . Furthermore, the engagement may produce a haptic and/or auditory feedback (e.g., audible click) to notify an adult vaper that the nicotine pod assembly  300  is properly seated within the through hole  150  of the device body  100 . 
       FIG.  16    is a partially exploded view involving the front cover, the frame, and the rear cover in  FIG.  14   . Referring to  FIG.  16   , various mechanical elements, electronic elements, and/or circuitry associated with the operation of the nicotine e-vaping device  500  may be secured to the frame  106 . The front cover  104  and the rear cover  108  may be configured to engage with the frame  106  via a snap-fit arrangement. In an example embodiment, the front cover  104  and the rear cover  108  include clips configured to interlock with corresponding mating members of the frame  106 . The clips may be in a form of tabs with orifices configured to receive the corresponding mating members (e.g., protrusions with beveled edges) of the frame  106 . In  FIG.  16   , the front cover  104  has two rows with four clips each (for a total of eight clips for the front cover  104 ). Similarly, the rear cover  108  has two rows with four clips each (for a total of eight clips for the rear cover  108 ). The corresponding mating members of the frame  106  may on the inner sidewalls of the frame  106 . As a result, the engaged clips and mating members may be hidden from view when the front cover  104  and the rear cover  108  are snapped together. Alternatively, the front cover  104  and/or the rear cover  108  may be configured to engage with the frame  106  via an interference fit. However, it should be understood that the front cover  104 , the frame  106 , and the rear cover  108  may be coupled via other suitable arrangements and techniques. 
       FIG.  17    is a perspective view of the nicotine pod assembly of the nicotine e-vaping device in  FIG.  6   .  FIG.  18    is another perspective view of the nicotine pod assembly of  FIG.  17   .  FIG.  19    is another perspective view of the nicotine pod assembly of  FIG.  18   . Referring to  FIGS.  17 - 19   , the nicotine pod assembly  300  for the nicotine e-vaping device  500  includes a pod body configured to hold a nicotine pre-vapor formulation. The pod body has an upstream end and a downstream end. The upstream end of the pod body defines a cavity  310  ( FIG.  20   ). The downstream end of the pod body defines a pod outlet  304  that is in fluidic communication with the cavity  310  at the upstream end. A connector module  320  is configured to be seated within the cavity  310  of the pod body. The connector module  320  includes an external face and a side face. The external face of the connector module  320  forms an exterior of the pod body. 
     The external face of the connector module  320  defines a pod inlet  322 . The pod inlet  322  (through which air enters during vaping) is in fluidic communication with the pod outlet  304  (through which nicotine vapor exits during vaping). The pod inlet  322  is shown in  FIG.  19    as being in a form of a slot. However, it should be understood that example embodiments are not limited thereto and that other forms are possible. When the connector module  320  is seated within the cavity  310  of the pod body, the external face of the connector module  320  remains visible, while the side face of the connector module  320  becomes mostly obscured so as to be only partially viewable through the pod inlet  322  based on a given angle. 
     The external face of the connector module  320  includes at least one electrical contact. The at least one electrical contact may include a plurality of power contacts. For instance, the plurality of power contacts may include a first power contact  324   a  and a second power contact  324   b . The first power contact  324   a  of the nicotine pod assembly  300  is configured to electrically connect with the first pair of power contacts (e.g., the pair adjacent to the first upstream protrusion  128   a  in  FIG.  12   ) of the device electrical connector  132  of the device body  100 . Similarly, the second power contact  324   b  of the nicotine pod assembly  300  is configured to electrically connect with the second pair of power contacts (e.g., the pair adjacent to the second upstream protrusion  128   b  in  FIG.  12   ) of the device electrical connector  132  of the device body  100 . In addition, the at least one electrical contact of the nicotine pod assembly  300  includes a plurality of data contacts  326 . The plurality of data contacts  326  of the nicotine pod assembly  300  are configured to electrically connect with the data contacts of the device electrical connector  132  (e.g., row of five projections in  FIG.  12   ). While two power contacts and five data contacts are shown in connection with the nicotine pod assembly  300 , it should be understood that other variations are possible depending on the design of the device body  100 . 
     In an example embodiment, the nicotine pod assembly  300  includes a front face, a rear face opposite the front face, a first side face between the front face and the rear face, a second side face opposite the first side face, an upstream end face, and a downstream end face opposite the upstream end face. The corners of the side and end faces (e.g., corner of the first side face and the upstream end face, corner of upstream end face and the second side face, corner of the second side face and the downstream end face, corner of the downstream end face and the first side face) may be rounded. However, in some instances, the corners may be angular. In addition, the peripheral edge of the front face may be in a form of a ledge. The external face of the connector module  320  may be regarded as being part of the upstream end face of the nicotine pod assembly  300 . The front face of the nicotine pod assembly  300  may be wider and longer than the rear face. In such an instance, the first side face and the second side face may be angled inwards towards each other. The upstream end face and the downstream end face may also be angled inwards towards each other. Because of the angled faces, the insertion of the nicotine pod assembly  300  will be unidirectional (e.g., from the front side (side associated with the front cover  104 ) of the device body  100 ). As a result, the possibility that the nicotine pod assembly  300  will be improperly inserted into the device body  100  can be reduced or prevented. 
     As illustrated, the pod body of the nicotine pod assembly  300  includes a first housing section  302  and a second housing section  308 . The first housing section  302  has a downstream end defining the pod outlet  304 . The rim of the pod outlet  304  may optionally be a sunken or indented region. In such an instance, this region may resemble a cove, wherein the side of the rim adjacent to the rear face of the nicotine pod assembly  300  may be open, while the side of the rim adjacent to the front face may be surrounded by a raised portion of the downstream end of the first housing section  302 . The raised portion may function as a stopper for the distal end of the mouthpiece  102 . As a result, this configuration for the pod outlet  304  may facilitate the receiving and aligning of the distal end of the mouthpiece  102  (e.g.,  FIG.  11   ) via the open side of the rim and its subsequent seating against the raised portion of the downstream end of the first housing section  302 . In a non-limiting embodiment, the distal end of the mouthpiece  102  may also include (or be formed of) a resilient material to help create a seal around the pod outlet  304  when the nicotine pod assembly  300  is properly inserted within the through hole  150  of the device body  100 . 
     The downstream end of the first housing section  302  additionally defines at least one downstream recess. In an example embodiment, the at least one downstream recess is in a form of a first downstream recess  306   a  and a second downstream recess  306   b . The pod outlet  304  may be between the first downstream recess  306   a  and the second downstream recess  306   b . The first downstream recess  306   a  and the second downstream recess  306   b  are configured to engage with the first downstream protrusion  130   a  and the second downstream protrusion  130   b , respectively, of the device body  100 . As shown in  FIG.  11   , the first downstream protrusion  130   a  and the second downstream protrusion  130   b  of the device body  100  may be disposed on adjacent corners of the downstream sidewall of the through hole  150 . The first downstream recess  306   a  and the second downstream recess  306   b  may each be in a form of a V-shaped notch. In such an instance, each of the first downstream protrusion  130   a  and the second downstream protrusion  130   b  of the device body  100  may be in a form of a wedge-shaped structure configured to engage with a corresponding V-shaped notch of the first downstream recess  306   a  and the second downstream recess  306   b . The first downstream recess  306   a  may abut the corner of the downstream end face and the first side face, while the second downstream recess  306   b  may abut the corner of the downstream end face and the second side face. As a result, the edges of the first downstream recess  306   a  and the second downstream recess  306   b  adjacent to the first side face and the second side face, respectively, may be open. In such an instance, as shown in  FIG.  18   , each of the first downstream recess  306   a  and the second downstream recess  306   b  may be a 3-sided recess. 
     The second housing section  308  has an upstream end defining the cavity  310  ( FIG.  20   ). The cavity  310  is configured to receive the connector module  320  ( FIG.  21   ). In addition, the upstream end of the second housing section  308  defines at least one upstream recess. In an example embodiment, the at least one upstream recess is in a form of a first upstream recess  312   a  and a second upstream recess  312   b . The pod inlet  322  may be between the first upstream recess  312   a  and the second upstream recess  312   b . The first upstream recess  312   a  and the second upstream recess  312   b  are configured to engage with the first upstream protrusion  128   a  and the second upstream protrusion  128   b , respectively, of the device body  100 . As shown in  FIG.  12   , the first upstream protrusion  128   a  and the second upstream protrusion  128   b  of the device body  100  may be disposed on adjacent corners of the upstream sidewall of the through hole  150 . A depth of each of the first upstream recess  312   a  and the second upstream recess  312   b  may be greater than a depth of each of the first downstream recess  306   a  and the second downstream recess  306   b . A terminus of each of the first upstream recess  312   a  and the second upstream recess  312   b  may also be more rounded than a terminus of each of the first downstream recess  306   a  and the second downstream recess  306   b . For instance, the first upstream recess  312   a  and the second upstream recess  312   b  may each be in a form of a U-shaped indentation. In such an instance, each of the first upstream protrusion  128   a  and the second upstream protrusion  128   b  of the device body  100  may be in a form of a rounded knob configured to engage with a corresponding U-shaped indentation of the first upstream recess  312   a  and the second upstream recess  312   b . The first upstream recess  312   a  may abut the corner of the upstream end face and the first side face, while the second upstream recess  312   b  may abut the corner of the upstream end face and the second side face. As a result, the edges of the first upstream recess  312   a  and the second upstream recess  312   b  adjacent to the first side face and the second side face, respectively, may be open. 
     The first housing section  302  may define a nicotine reservoir within configured to hold the nicotine pre-vapor formulation. The nicotine reservoir may be configured to hermetically seal the nicotine pre-vapor formulation until an activation of the nicotine pod assembly  300  to release the nicotine pre-vapor formulation from the nicotine reservoir. As a result of the hermetic seal, the nicotine pre-vapor formulation may be isolated from the environment as well as the internal elements of the nicotine pod assembly  300  that may potentially react with the nicotine pre-vapor formulation, thereby reducing or preventing the possibility of adverse effects to the shelf-life and/or sensorial characteristics (e.g., flavor) of the nicotine pre-vapor formulation. The second housing section  308  may contain structures configured to activate the nicotine pod assembly  300  and to receive and heat the nicotine pre-vapor formulation released from the nicotine reservoir after the activation. 
     The nicotine pod assembly  300  may be activated manually by an adult vaper prior to the insertion of the nicotine pod assembly  300  into the device body  100 . Alternatively, the nicotine pod assembly  300  may be activated as part of the insertion of the nicotine pod assembly  300  into the device body  100 . In an example embodiment, the second housing section  308  of the pod body includes a perforator configured to release the nicotine pre-vapor formulation from the nicotine reservoir during the activation of the nicotine pod assembly  300 . The perforator may be in a form of a first activation pin  314   a  and a second activation pin  314   b , which will be discussed in more detail herein. 
     To activate the nicotine pod assembly  300  manually, an adult vaper may press the first activation pin  314   a  and the second activation pin  314   b  inward (e.g., simultaneously or sequentially) prior to inserting the nicotine pod assembly  300  into the through hole  150  of the device body  100 . For instance, the first activation pin  314   a  and the second activation pin  314   b  may be manually pressed until the ends thereof are substantially even with the upstream end face of the nicotine pod assembly  300 . In an example embodiment, the inward movement of the first activation pin  314   a  and the second activation pin  314   b  causes a seal of the nicotine reservoir to be punctured or otherwise compromised so as to release the nicotine pre-vapor formulation therefrom. 
     Alternatively, to activate the nicotine pod assembly  300  as part of the insertion of the nicotine pod assembly  300  into the device body  100 , the nicotine pod assembly  300  is initially positioned such that the first upstream recess  312   a  and the second upstream recess  312   b  are engaged with the first upstream protrusion  128   a  and the second upstream protrusion  128   b , respectively (e.g., upstream engagement). Because each of the first upstream protrusion  128   a  and the second upstream protrusion  128   b  of the device body  100  may be in a form of a rounded knob configured to engage with a corresponding U-shaped indentation of the first upstream recess  312   a  and the second upstream recess  312   b , the nicotine pod assembly  300  may be subsequently pivoted with relative ease about the first upstream protrusion  128   a  and the second upstream protrusion  128   b  and into the through hole  150  of the device body  100 . 
     With regard to the pivoting of the nicotine pod assembly  300 , the axis of rotation may be regarded as extending through the first upstream protrusion  128   a  and the second upstream protrusion  128   b  and oriented orthogonally to a longitudinal axis of the device body  100 . During the initial positioning and subsequent pivoting of the nicotine pod assembly  300 , the first activation pin  314   a  and the second activation pin  314   b  will come into contact with the upstream sidewall of the through hole  150  and transition from a protracted state to a retracted state as the first activation pin  314   a  and the second activation pin  314   b  are pushed (e.g., simultaneously) into the second housing section  308  as the nicotine pod assembly  300  progresses into the through hole  150 . When the downstream end of the nicotine pod assembly  300  reaches the vicinity of the downstream sidewall of the through hole  150  and comes into contact with the first downstream protrusion  130   a  and the second downstream protrusion  130   b , the first downstream protrusion  130   a  and the second downstream protrusion  130   b  will retract and then resiliently protract (e.g., spring back) when the positioning of the nicotine pod assembly  300  allows the first downstream protrusion  130   a  and the second downstream protrusion  130   b  of the device body  100  to engage with the first downstream recess  306   a  and the second downstream recess  306   b , respectively, of the nicotine pod assembly  300  (e.g., downstream engagement). 
     As noted supra, according to an example embodiment, the mouthpiece  102  is secured to the retention structure  140  (of which the first downstream protrusion  130   a  and the second downstream protrusion  130   b  are a part). In such an instance, the retraction of the first downstream protrusion  130   a  and the second downstream protrusion  130   b  from the through hole  150  will cause a simultaneous shift of the mouthpiece  102  by a corresponding distance in the same direction (e.g., downstream direction). Conversely, the mouthpiece  102  will spring back simultaneously with the first downstream protrusion  130   a  and the second downstream protrusion  130   b  when the nicotine pod assembly  300  has been sufficiently inserted to facilitate downstream engagement. In addition to the resilient engagement by the first downstream protrusion  130   a  and the second downstream protrusion  130   b , the distal end of the mouthpiece  102  is configured to also be biased against the nicotine pod assembly  300  (and aligned with the pod outlet  304  so as to form a relatively vapor-tight seal) when the nicotine pod assembly  300  is properly seated within the through hole  150  of the device body  100 . 
     Furthermore, the downstream engagement may produce an audible click and/or a haptic feedback to indicate that the nicotine pod assembly  300  is properly seated within the through hole  150  of the device body  100 . When properly seated, the nicotine pod assembly  300  will be connected to the device body  100  mechanically, electrically, and fluidically. Although the non-limiting embodiments herein describe the upstream engagement of the nicotine pod assembly  300  as occurring before the downstream engagement, it should be understood that the pertinent mating, activation, and/or electrical arrangements may be reversed such that the downstream engagement occurs before the upstream engagement. 
       FIG.  20    is a perspective view of the nicotine pod assembly of  FIG.  19    without the connector module. Referring to  FIG.  20   , the upstream end of the second housing section  308  defines a cavity  310 . As noted supra, the cavity  310  is configured to receive the connector module  320  (e.g., via interference fit). In an example embodiment, the cavity  310  is situated between the first upstream recess  312   a  and the second upstream recess  312   b  and also situated between the first activation pin  314   a  and the second activation pin  314   b . In the absence of the connector module  320 , an insert  342  ( FIG.  24   ) and an absorbent material  346  ( FIG.  25   ) are visible through a recessed opening in the cavity  310 . The insert  342  is configured to retain the absorbent material  346 . The absorbent material  346  is configured to absorb and hold a quantity of the nicotine pre-vapor formulation released from the nicotine reservoir when the nicotine pod assembly  300  is activated. The insert  342  and the absorbent material  346  will be discussed in more detail herein. 
       FIG.  21    is a perspective view of the connector module in  FIG.  19   .  FIG.  22    is another perspective view of the connector module of  FIG.  21   . Referring to  FIGS.  21 - 22   , the general framework of the connector module  320  includes a module housing  354  and a face plate  366 . In addition, the connector module  320  has a plurality of faces, including an external face and a side face, wherein the external face is adjacent to the side face. In an example embodiment, the external face of the connector module  320  is composed of upstream surfaces of the face plate  366 , the first power contact  324   a , the second power contact  324   b , and the data contacts  326 . The side face of the connector module  320  is part of the module housing  354 . The side face of the connector module  320  defines a first module inlet  330  and a second module inlet  332 . Furthermore, the two lateral faces adjacent to the side face (which are also part of the module housing  354 ) may include rib structures (e.g., crush ribs) configured to facilitate an interference fit when the connector module  320  is seated within the cavity  310  of the pod body. For instance, each of the two lateral faces may include a pair of rib structures that taper away from the face plate  366 . As a result, the module housing  354  will encounter increasing resistance via the friction of the rib structures against the lateral walls of the cavity  310  as the connector module  320  is pressed into the cavity  310  of the pod body. When the connector module  320  is seated within the cavity  310 , the face plate  366  may be substantially flush with the upstream end of the second housing section  308 . Also, the side face (which defines the first module inlet  330  and the second module inlet  332 ) of the connector module  320  will be facing a sidewall of the cavity  310 . 
     The face plate  366  of the connector module  320  may have a grooved edge  328  that, in combination with a corresponding side surface of the cavity  310 , defines the pod inlet  322 . However, it should be understood that example embodiments are not limited thereto. For instance, the face plate  366  of the connector module  320  may be alternatively configured so as to entirely define the pod inlet  322 . The side face (which defines the first module inlet  330  and the second module inlet  332 ) of the connector module  320  and the sidewall of the cavity  310  (which faces the side face) define an intermediate space in between. The intermediate space is downstream from the pod inlet  322  and upstream from the first module inlet  330  and the second module inlet  332 . Thus, in an example embodiment, the pod inlet  322  is in fluidic communication with both the first module inlet  330  and the second module inlet  332  via the intermediate space. The first module inlet  330  may be larger than the second module inlet  332 . In such an instance, when incoming air is received by the pod inlet  322  during vaping, the first module inlet  330  may receive a primary flow (e.g., larger flow) of the incoming air, while the second module inlet  332  may receive a secondary flow (e.g., smaller flow) of the incoming air. 
     As shown in  FIG.  22   , the connector module  320  includes a wick  338  that is configured to transfer a nicotine pre-vapor formulation to a heater  336 . The heater  336  is configured to heat the nicotine pre-vapor formulation during vaping to generate a vapor. The heater  336  may be mounted in the connector module  320  via a contact core  334 . The heater  336  is electrically connected to at least one electrical contact of the connector module  320 . For instance, one end (e.g., first end) of the heater  336  may be connected to the first power contact  324   a , while the other end (e.g., second end) of the heater  336  may be connected to the second power contact  324   b . In an example embodiment, the heater  336  includes a folded heating element. In such an instance, the wick  338  may have a planar form configured to be held by the folded heating element. When the connector module  320  is seated within the cavity  310  of the pod body, the wick  338  is configured to be in fluidic communication with the absorbent material  346  such that the nicotine pre-vapor formulation that will be in the absorbent material  346  (when the nicotine pod assembly  300  is activated) will be transferred to the wick  338  via capillary action. 
       FIG.  23    is an exploded view involving the wick, heater, electrical leads, and contact core in  FIG.  22   . Referring to  FIG.  23   , the wick  338  may be a fibrous pad or other structure with pores/interstices designed for capillary action. In addition, the wick  338  may have a shape of an irregular hexagon, although example embodiments are not limited thereto. The wick  338  may be fabricated into the hexagonal shape or cut from a larger sheet of material into this shape. Because the lower section of the wick  338  is tapered towards the winding section of the heater  336 , the likelihood of the nicotine pre-vapor formulation being in a part of the wick  338  that continuously evades vaporization (due to its distance from the heater  336 ) can be reduced or avoided. 
     In an example embodiment, the heater  336  is configured to undergo Joule heating (which is also known as ohmic/resistive heating) upon the application of an electric current thereto. Stated in more detail, the heater  336  may be formed of one or more conductors and configured to produce heat when an electric current passes therethrough. The electric current may be supplied from a power source (e.g., battery) within the device body  100  and conveyed to the heater  336  via the first power contact  324   a  and the first electrical lead  340   a  (or via the second power contact  324   b  and the second electrical lead  340   b ). 
     Suitable conductors for the heater  336  include an iron-based alloy (e.g., stainless steel) and/or a nickel-based alloy (e.g., nichrome). The heater  336  may be fabricated from a conductive sheet (e.g., metal, alloy) that is stamped to cut a winding pattern therefrom. The winding pattern may have curved segments alternately arranged with horizontal segments so as to allow the horizontal segments to zigzag back and forth while extending in parallel. In addition, a width of each of the horizontal segments of the winding pattern may be substantially equal to a spacing between adjacent horizontal segments of the winding pattern, although example embodiments are not limited thereto. To obtain the form of the heater  336  shown in the drawings, the winding pattern may be folded so as to grip the wick  338 . 
     The heater  336  may be secured to the contact core  334  with a first electrical lead  340   a  and a second electrical lead  340   b . The contact core  334  is formed of an insulating material and configured to electrically isolate the first electrical lead  340   a  from the second electrical lead  340   b . In an example embodiment, the first electrical lead  340   a  and the second electrical lead  340   b  each define a female aperture that is configured to engage with corresponding male members of the contact core  334 . Once engaged, the first end and the second end of the heater  336  may be secured (e.g., welded, soldered, brazed) to the first electrical lead  340   a  and the second electrical lead  340   b , respectively. The contact core  334  may then be seated within a corresponding socket in the module housing  354  (e.g., via interference fit). Upon completion of the assembly of the connector module  320 , the first electrical lead  340   a  will electrically connect a first end of the heater  336  with the first power contact  324   a , while the second electrical lead  340   b  will electrically connect a second end of the heater  336  with the second power contact  324   b . The heater and associated structures are discussed in more detail in U.S. application Ser. No. 15/729,909, titled “Folded Heater For Nicotine electronic vaping device”, filed Oct. 11, 2017, the entire contents of which is incorporated herein by reference. 
       FIG.  24    is an exploded view involving the first housing section of the nicotine pod assembly of  FIG.  17   . Referring to  FIG.  24   , the first housing section  302  includes a vapor channel  316 . The vapor channel  316  is configured to receive nicotine vapor generated by the heater  336  and is in fluidic communication with the pod outlet  304 . In an example embodiment, the vapor channel  316  may gradually increase in size (e.g., diameter) as it extends towards the pod outlet  304 . In addition, the vapor channel  316  may be integrally formed with the first housing section  302 . A wrap  318 , an insert  342 , and a seal  344  are disposed at an upstream end of the first housing section  302  to define the nicotine reservoir of the nicotine pod assembly  300 . For instance, the wrap  318  may be disposed on the rim of the first housing section  302 . The insert  342  may be seated within the first housing section  302  such that the peripheral surface of the insert  342  engages with the inner surface of the first housing section  302  along the rim (e.g., via interference fit) such that the interface of the peripheral surface of the insert  342  and the inner surface of the first housing section  302  is fluid-tight (e.g., liquid-tight and/or air-tight). Furthermore, the seal  344  is attached to the upstream side of the insert  342  to close off the nicotine reservoir outlets in the insert  342  so as to provide a fluid-tight (e.g., liquid-tight and/or air-tight) containment of the nicotine pre-vapor formulation in the nicotine reservoir. 
     In an example embodiment, the insert  342  includes a holder portion that projects from the upstream side (as shown in  FIG.  24   ) and a connector portion that projects from the downstream side (hidden from view in  FIG.  24   ). The holder portion of the insert  342  is configured to hold the absorbent material  346 , while the connector portion of the insert  342  is configured to engage with the vapor channel  316  of the first housing section  302 . The connector portion of the insert  342  may be configured to be seated within the vapor channel  316  and, thus, engage the interior of the vapor channel  316 . Alternatively, the connector portion of the insert  342  may be configured to receive the vapor channel  316  and, thus, engage with the exterior of the vapor channel  316 . The insert  342  also defines nicotine reservoir outlets through which the nicotine pre-vapor formulation flows when the seal  344  is punctured (as shown in  FIG.  24   ) during the activation of the nicotine pod assembly  300 . The holder portion and the connector portion of the insert  342  may be between the nicotine reservoir outlets (e.g., first and second nicotine reservoir outlets), although example embodiments are not limited thereto. Furthermore, the insert  342  defines a vapor conduit extending through the holder portion and the connector portion. As a result, when the insert  342  is seated within the first housing section  302 , the vapor conduit of the insert  342  will be aligned with and in fluidic communication with the vapor channel  316  so as to form a continuous path through the nicotine reservoir to the pod outlet  304  for the nicotine vapor generated by the heater  336  during vaping. 
     The seal  344  is attached to the upstream side of the insert  342  so as to cover the nicotine reservoir outlets in the insert  342 . In an example embodiment, the seal  344  defines an opening (e.g., central opening) configured to provide the pertinent clearance to accommodate the holder portion (that projects from the upstream side of the insert  342 ) when the seal  344  is attached to the insert  342 . In  FIG.  24   , it should be understood that the seal  344  is shown in a punctured state. In particular, when punctured by the first activation pin  314   a  and the second activation pin  314   b  of the nicotine pod assembly  300 , the two punctured sections of the seal  344  will be pushed into the nicotine reservoir as flaps (as shown in  FIG.  24   ), thus creating two punctured openings (e.g., one on each side of the central opening) in the seal  344 . The size and shape of the punctured openings in the seal  344  may correspond to the size and shape of the nicotine reservoir outlets in the insert  342 . In contrast, when in an unpunctured state, the seal  344  will have a planar form and only one opening (e.g., central opening). The seal  344  is designed to be strong enough to remain intact during the normal movement and/or handling of the nicotine pod assembly  300  so as to avoid being prematurely/inadvertently breached. For instance, the seal  344  may be a coated foil (e.g., aluminum-backed Tritan). 
       FIG.  25    is a partially exploded view involving the second housing section of the nicotine pod assembly of  FIG.  17   . Referring to  FIG.  25   , the second housing section  308  is structured to contain various elements configured to release, receive, and heat the nicotine pre-vapor formulation. For instance, the first activation pin  314   a  and the second activation pin  314   b  are configured to puncture the nicotine reservoir in the first housing section  302  to release the nicotine pre-vapor formulation. Each of the first activation pin  314   a  and the second activation pin  314   b  has a distal end that extends through corresponding openings in the second housing section  308 . In an example embodiment, the distal ends of the first activation pin  314   a  and the second activation pin  314   b  are visible after assembly (e.g.,  FIG.  17   ), while the remainder of the first activation pin  314   a  and the second activation pin  314   b  are hidden from view within the nicotine pod assembly  300 . In addition, each of the first activation pin  314   a  and the second activation pin  314   b  has a proximal end that is positioned so as to be adjacent to and upstream from the seal  344  prior to activation of the nicotine pod assembly  300 . When the first activation pin  314   a  and the second activation pin  314   b  are pushed into the second housing section  308  to activate the nicotine pod assembly  300 , the proximal end of each of the first activation pin  314   a  and the second activation pin  314   b  will advance through the insert  342  and, as a result, puncture the seal  344 , which will release the nicotine pre-vapor formulation from the nicotine reservoir. The movement of the first activation pin  314   a  may be independent of the movement of the second activation pin  314   b  (and vice versa). The first activation pin  314   a  and the second activation pin  314   b  will be discussed in more detail herein. 
     The absorbent material  346  is configured to engage with the holder portion of the insert  342  (which, as shown in  FIG.  24   , projects from the upstream side of the insert  342 ). The absorbent material  346  may have an annular form, although example embodiments are not limited thereto. As depicted in  FIG.  25   , the absorbent material  346  may resemble a hollow cylinder. In such an instance, the outer diameter of the absorbent material  346  may be substantially equal to (or slightly larger than) the length of the wick  338 . The inner diameter of the absorbent material  346  may be smaller than the average outer diameter of the holder portion of the insert  342  so as to result in an interference fit. To facilitate the engagement with the absorbent material  346 , the tip of the holder portion of the insert  342  may be tapered. In addition, although hidden from view in  FIG.  25   , the downstream side of the second housing section  308  may define a concavity configured receive and support the absorbent material  346 . An example of such a concavity may be a circular chamber that is in fluidic communication with and downstream from the cavity  310 . The absorbent material  346  is configured to receive and hold a quantity of the nicotine pre-vapor formulation released from the nicotine reservoir when the nicotine pod assembly  300  is activated. 
     The wick  338  is positioned within the nicotine pod assembly  300  so as to be in fluidic communication with the absorbent material  346  such that the nicotine pre-vapor formulation can be drawn from the absorbent material  346  to the heater  336  via capillary action. The wick  338  may physically contact an upstream side of the absorbent material  346  (e.g., bottom of the absorbent material  346  based on the view shown in  FIG.  25   ). In addition, the wick  338  may be aligned with a diameter of the absorbent material  346 , although example embodiments are not limited thereto. 
     As illustrated in  FIG.  25    (as well as previous  FIG.  23   ), the heater  336  may have a folded configuration so as to grip and establish thermal contact with the opposing surfaces of the wick  338 . The heater  336  is configured to heat the wick  338  during vaping to generate a vapor. To facilitate such heating, the first end of the heater  336  may be electrically connected to the first power contact  324   a  via the first electrical lead  340   a , while the second end of the heater  336  may be electrically connected to the second power contact  324   b  via the second electrical lead  340   b . As a result, an electric current may be supplied from a power source (e.g., battery) within the device body  100  and conveyed to the heater  336  via the first power contact  324   a  and the first electrical lead  340   a  (or via the second power contact  324   b  and the second electrical lead  340   b ). The first electrical lead  340   a  and the second electrical lead  340   b  (which are shown separately in  FIG.  23   ) may be engaged with the contact core  334  (as shown in  FIG.  25   ). The relevant details of other aspects of the connector module  320 , which is configured to be seated within the cavity  310  of the second housing section  308 , that have been discussed supra (e.g., in connection with  FIGS.  21 - 22   ) and will not be repeated in this section in the interest of brevity. During vaping, the nicotine vapor generated by the heater  336  is drawn through the vapor conduit of the insert  342 , through the vapor channel  316  of the first housing section  302 , out the pod outlet  304  of the nicotine pod assembly  300 , and through the vapor passage  136  of the mouthpiece  102  to the vapor outlet(s). 
       FIG.  26    is an exploded view of the activation pin in  FIG.  25   . Referring to  FIG.  26   , the activation pin may be in the form of a first activation pin  314   a  and a second activation pin  314   b . While two activation pins are shown and discussed in connection with the non-limiting embodiments herein, it should be understood that, alternatively, the nicotine pod assembly  300  may include only one activation pin. In  FIG.  26   , the first activation pin  314   a  may include a first blade  348   a , a first actuator  350   a , and a first O-ring  352   a . Similarly, the second activation pin  314   b  may include a second blade  348   b , a second actuator  350   b , and a second O-ring  352   b.    
     In an example embodiment, the first blade  348   a  and the second blade  348   b  are configured to be mounted or attached to upper portions (e.g., proximal portions) of the first actuator  350   a  and the second actuator  350   b , respectively. The mounting or attachment may be achieved via a snap-fit connection, an interference fit (e.g., friction fit) connection, an adhesive, or other suitable coupling technique. The top of each of the first blade  348   a  and the second blade  348   b  may have one or more curved or concave edges that taper upward to a pointed tip. For instance, each of the first blade  348   a  and the second blade  348   b  may have two pointed tips with a concave edge therebetween and a curved edge adjacent to each pointed tip. The radii of curvature of the concave edge and the curved edges may be the same, while their arc lengths may differ. The first blade  348   a  and the second blade  348   b  may be formed of a sheet metal (e.g., stainless steel) that is cut or otherwise shaped to have the desired profile and bent to its final form. In another instance, the first blade  348   a  and the second blade  348   b  may be formed of plastic. 
     Based on a plan view, the size and shape of the first blade  348   a , the second blade  348   b , and portions of the first actuator  350   a  and the second actuator  350   b  on which they are mounted may correspond to the size and shape of the nicotine reservoir outlets in the insert  342 . Additionally, as shown in  FIG.  26   , the first actuator  350   a  and the second actuator  350   b  may include projecting edges (e.g., curved inner lips which face each other) configured to push the two punctured sections of the seal  344  into the nicotine reservoir as the first blade  348   a  and the second blade  348   b  advance into the nicotine reservoir. In a non-limiting embodiment, when the first activation pin  314   a  and the second activation pin  314   b  are fully inserted into the nicotine pod assembly  300 , the two flaps (from the two punctured sections of the seal  344 , as shown in  FIG.  24   ) may be between the curved sidewalls of the nicotine reservoir outlets of the insert  342  and the corresponding curvatures of the projecting edges of the first actuator  350   a  and the second actuator  350   b . As a result, the likelihood of the two punctured openings in the seal  344  becoming obstructed (by the two flaps from the two punctured sections) may be reduced or prevented. Furthermore, the first actuator  350   a  and the second actuator  350   b  may be configured to guide the nicotine pre-vapor formulation from the nicotine reservoir toward the absorbent material  346 . 
     The lower portion (e.g., distal portion) of each of the first actuator  350   a  and the second actuator  350   b  is configured to extend through a bottom section (e.g., upstream end) of the second housing section  308 . This rod-like portion of each of the first actuator  350   a  and the second actuator  350   b  may also be referred to as the shaft. The first O-ring  352   a  and the second O-ring  352   b  may be seated in annular grooves in the respective shafts of the first actuator  350   a  and the second actuator  350   b . The first O-ring  352   a  and the second O-ring  352   b  are configured to engage with the shafts of the first actuator  350   a  and the second actuator  350   b  as well as the inner surfaces of the corresponding openings in the second housing section  308  in order to provide a fluid-tight seal. As a result, when the first activation pin  314   a  and the second activation pin  314   b  are pushed inward to activate the nicotine pod assembly  300 , the first O-ring  352   a  and the second O-ring  352   b  may move together with the respective shafts of the first actuator  350   a  and the second actuator  350   b  within the corresponding openings in the second housing section  308  while maintaining their respective seals, thereby helping to reduce or prevent leakage of the nicotine pre-vapor formulation through the openings in the second housing section  308  for the first activation pin  314   a  and the second activation pin  314   b . The first O-ring  352   a  and the second O-ring  352   b  may be formed of silicone. 
       FIG.  27    is a perspective view of the connector module of  FIG.  22    without the wick, heater, electrical leads, and contact core.  FIG.  28    is an exploded view of the connector module of  FIG.  27   . Referring to  FIGS.  27 - 28   , the module housing  354  and the face plate  366  generally form the exterior framework of the connector module  320 . The module housing  354  defines the first module inlet  330  and a grooved edge  356 . The grooved edge  356  of the module housing  354  exposes the second module inlet  332  (which is defined by the bypass structure  358 ). However, it should be understood that the grooved edge  356  may also be regarded as defining a module inlet (e.g., in combination with the face plate  366 ). The face plate  366  has a grooved edge  328  which, together with the corresponding side surface of the cavity  310  of the second housing section  308 , defines the pod inlet  322 . In addition, the face plate  366  defines a first contact opening, a second contact opening, and a third contact opening. The first contact opening and the second contact opening may be square-shaped and configured to expose the first power contact  324   a  and the second power contact  324   b , respectively, while the third contact opening may be rectangular-shaped and configured to expose the plurality of data contacts  326 , although example embodiments are not limited thereto. 
     The first power contact  324   a , the second power contact  324   b , a printed circuit board (PCB)  362 , and the bypass structure  358  are disposed within the exterior framework formed by the module housing  354  and the face plate  366 . The printed circuit board (PCB)  362  includes the plurality of data contacts  326  on its upstream side (which is hidden from view in  FIG.  28   ) and a sensor  364  on its downstream side. The bypass structure  358  defines the second module inlet  332  and a bypass outlet  360 . 
     During assembly, the first power contact  324   a  and the second power contact  324   b  are positioned so as to be visible through the first contact opening and the second contact opening, respectively, of the face plate  366 . Additionally, the printed circuit board (PCB)  362  is positioned such that the plurality of data contacts  326  on its upstream side are visible through the third contact opening of the face plate  366 . The printed circuit board (PCB)  362  may also overlap the rear surfaces of the first power contact  324   a  and the second power contact  324   b . The bypass structure  358  is positioned on the printed circuit board (PCB)  362  such that the sensor  364  is within an air flow path defined by the second module inlet  332  and the bypass outlet  360 . When assembled, the bypass structure  358  and the printed circuit board (PCB)  362  may be regarded as being surrounded on at least four sides by the meandering structures of the first power contact  324   a  and the second power contact  324   b . In an example embodiment, the bifurcated ends of the first power contact  324   a  and the second power contact  324   b  are configured to electrically connect to the first electrical lead  340   a  and the second electrical lead  340   b.    
     When incoming air is received by the pod inlet  322  during vaping, the first module inlet  330  may receive a primary flow (e.g., larger flow) of the incoming air, while the second module inlet  332  may receive a secondary flow (e.g., smaller flow) of the incoming air. The secondary flow of the incoming air may improve the sensitivity of the sensor  364 . After exiting the bypass structure  358  through the bypass outlet  360 , the secondary flow rejoins with the primary flow to form a combined flow that is drawn into and through the contact core  334  so as to encounter the heater  336  and the wick  338 . In a non-limiting embodiment, the primary flow may be 60-95% (e.g., 80-90%) of the incoming air, while the secondary flow may be 5-40% (e.g., 10-20%) of the incoming air. 
     The first module inlet  330  may be a resistance-to-draw (RTD) port, while the second module inlet  332  may be a bypass port. In such a configuration, the resistance-to-draw for the nicotine e-vaping device  500  may be adjusted by changing the size of the first module inlet  330  (rather than changing the size of the pod inlet  322 ). In an example embodiment, the size of the first module inlet  330  may be selected such that the resistance-to-draw is between 25-100 mmH 2 O (e.g., between 30-50 mmH 2 O). For instance, a diameter of 1.0 mm for the first module inlet  330  may result in a resistance-to-draw of 88.3 mmH 2 O. In another instance, a diameter of 1.1 mm for the first module inlet  330  may result in a resistance-to-draw of 73.6 mmH 2 O. In another instance, a diameter of 1.2 mm for the first module inlet  330  may result in a resistance-to-draw of 58.7 mmH 2 O. In yet another instance, a diameter of 1.3 mm for the first module inlet  330  may result in a resistance-to-draw of 43.8 mmH 2 O. Notably, the size of the first module inlet  330 , because of its internal arrangement, may be adjusted without affecting the external aesthetics of the nicotine pod assembly  300 , thereby allowing for a more standardized product design for pod assemblies with various resistance-to-draw (RTD) while also reducing the likelihood of an inadvertent blockage of the incoming air. 
       FIG.  29    illustrates electrical systems of a device body and a nicotine pod assembly of a nicotine e-vaping device according to one or more example embodiments. 
     Referring to  FIG.  29   , the electrical systems include a device body electrical system  2100  and a nicotine pod assembly electrical system  2200 . The device body electrical system  2100  may be included in the device body  100 , and the nicotine pod assembly electrical system  2200  may be included in the nicotine pod assembly  300  of the nicotine e-vaping device  500  discussed above with regard to  FIGS.  1 - 28   . 
     In the example embodiment shown in  FIG.  29   , the nicotine pod assembly electrical system  2200  includes the heater  336 , one or more pod sensors  2220  and a non-volatile memory (NVM)  2205 . The NVM  2205  may be an electrically erasable programmable read-only memory (EEPROM) integrated circuit (IC). The one or more pod sensors  2220  may include a temperature sensing transducer. 
     The nicotine pod assembly electrical system  2200  may further include a body electrical/data interface (not shown) for transferring power and/or data between the device body  100  and the nicotine pod assembly  300 . According to at least one example embodiment, the electrical contacts  324   a ,  324   b  and  326  shown in  FIG.  17   , for example, may serve as the body electrical/data interface. 
     The device body electrical system  2100  includes a controller  2105 , a power supply  2110 , device sensors or measurement circuits  2125 , a heating engine control circuit (also referred to as a heating engine shutdown circuit)  2127 , vaper indicators  2135 , on-product controls  2150  (e.g., buttons  118  and  120  shown in  FIG.  1   ), a memory  2130 , and a clock circuit  2128 . The device body electrical system  2100  may further include a pod electrical/data interface (not shown) for transferring power and/or data between the device body  100  and the nicotine pod assembly  300 . According to at least one example embodiment, the device electrical connector  132  shown in  FIG.  12   , for example, may serve as the pod electrical/data interface. 
     The power supply  2110  may be an internal power source to supply power to the device body  100  and the nicotine pod assembly  300  of the nicotine e-vaping device  500 . The supply of power from the power supply  2110  may be controlled by the controller  2105  through power control circuitry (not shown). The power control circuitry may include one or more switches or transistors to regulate power output from the power supply  2110 . The power supply  2110  may be a Lithium-ion battery or a variant thereof (e.g., a Lithium-ion polymer battery). 
     The controller  2105  may be configured to control overall operation of the nicotine e-vaping device  500 . According to at least some example embodiments, the controller  2105  may include processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. 
     In the example embodiment shown in  FIG.  29   , the controller  2105  is illustrated as a microcontroller including: input/output (I/O) interfaces, such as general purpose input/outputs (GPIOs), inter-integrated circuit (I 2 C) interfaces, serial peripheral interface bus (SPI) interfaces, or the like; a multichannel analog-to-digital converter (ADC); and a clock input terminal. However, example embodiments should not be limited to this example. In at least one example implementation, the controller  2105  may be a microprocessor. 
     The controller  2105  is communicatively coupled to the device sensors  2125 , the heating engine control circuit  2127 , vaper indicators  2135 , the memory  2130 , the on-product controls  2150 , the clock circuit  2128  and the power supply  2110 . 
     The heating engine control circuit  2127  is connected to the controller  2105  via a GPIO pin. The memory  2130  is connected to the controller  2105  via a SPI pin. The clock circuit  2128  is connected to a clock input pin of the controller  2105 . The vaper indicators  2135  are connected to the controller  2105  via an I 2 C interface pin and a GPIO pin. The device sensors  2125  are connected to the controller  2105  through respective pins of the multi-channel ADC. 
     The clock circuit  2128  may be a timing mechanism, such as an oscillator circuit, to enable the controller  2105  to track idle time, vaping length, a combination of idle time and vaping length, or the like, of the nicotine e-vaping device  500 . The clock circuit  2128  may also include a dedicated external clock crystal configured to generate the system clock for the nicotine e-vaping device  500 . 
     The memory  2130  may be a non-volatile memory configured to store one or more shutdown logs. In one example, the memory  2130  may store the one or more shutdown logs in one or more tables. The memory  2130  and the one or more shutdown logs stored therein will be discussed in more detail later. In one example, the memory  2130  may be an electrically erasable programmable read-only memory (EEPROM), such as a flash memory or the like. 
     Still referring to  FIG.  29   , the device sensors  2125  may include a plurality of sensor or measurement circuits configured to provide signals indicative of sensor or measurement information to the controller  2105 . In the example shown in  FIG.  29   , the device sensors  2125  include a heater current measurement circuit  21258 , a heater voltage measurement circuit  21252 , and a pod temperature measurement circuit  21250 . 
     The heater current measurement circuit  21258  may be configured to output (e.g., voltage) signals indicative of the current through the heater  336 . An example embodiment of the heater current measurement circuit  21258  will be discussed in more detail later with regard to  FIG.  35   . 
     The heater voltage measurement circuit  21252  may be configured to output (e.g., voltage) signals indicative of the voltage across the heater  336 . An example embodiment of the heater voltage measurement circuit  21252  will be discussed in more detail later with regard to  FIG.  34   . 
     The pod temperature measurement circuit  21250  may be configured to output (e.g., voltage) signals indicative of the resistance and/or temperature of one or more elements of the nicotine pod assembly  300 . Example embodiments of the pod temperature measurement circuit  21250  will be discussed in more detail later with regard to  FIGS.  36  and  37   . 
     As discussed above, the pod temperature measurement circuit  21250 , the heater current measurement circuit  21258  and the heater voltage measurement circuit  21252  are connected to the controller  2105  via pins of the multi-channel ADC. To measure characteristics and/or parameters of the nicotine e-vaping device  500  (e.g., voltage, current, resistance, temperature, or the like, of the heater  336 ), the multi-channel ADC at the controller  2105  may sample the output signals from the device sensors  2125  at a sampling rate appropriate for the given characteristic and/or parameter being measured by the respective device sensor. 
     Although not shown in  FIG.  29   , the pod sensors  2220  may also include the sensor  364  shown in  FIG.  28   . In at least one example embodiment, the sensor  364  may be a microelectromechanical system (MEMS) flow or pressure sensor or another type of sensor configured to measure air flow such as a hot-wire anemometer. 
     The heating engine control circuit  2127  is connected to the controller  2105  via a GPIO pin. The heating engine control circuit  2127  is configured to control (enable and/or disable) the heating engine of the nicotine e-vaping device  500  by controlling power to the heater  336 . As discussed in more detail later, the heating engine control circuit  2127  may disable the heating engine based on control signaling (sometimes referred to herein as device power state signals) from the controller  2105 . 
     When the nicotine pod assembly  300  is inserted into the device body  100 , the controller  2105  is also communicatively coupled to at least the NVM  2205  and the pod sensors  2220  via the I 2 C interface. In one example, the controller  2105  may obtain operating parameters for the nicotine pod assembly electrical system  2200  from the NVM  2205 . 
     The controller  2105  may control the vaper indicators  2135  to indicate statuses and/or operations of the nicotine e-vaping device  500  to an adult vaper. The vaper indicators  2135  may be at least partially implemented via a light guide (e.g., the light guide arrangement shown in  FIG.  1   ), and may include a power indicator (e.g., LED) that may be activated when the controller  2105  senses a button pressed by the adult vaper. The vaper indicators  2135  may also include a vibrator, speaker, or other feedback mechanisms, and may indicate a current state of an adult vaper-controlled vaping parameter (e.g., nicotine vapor volume). 
     Still referring to  FIG.  29   , the controller  2105  may control power to the heater  336  to heat the nicotine pre-vapor formulation in accordance with a heating profile (e.g., heating based on volume, temperature, flavor, or the like). The heating profile may be determined based on empirical data and may be stored in the NVM  2205  of the nicotine pod assembly  300 . 
       FIG.  30    is a simple block diagram illustrating a dry puff and auto shutdown control system  2300  according to example embodiments. For brevity, the dry puff and auto shutdown control system  2300  may be referred to herein as the auto shutdown control system  2300 . 
     The auto shutdown control system  2300  shown in  FIG.  30    may be implemented at the controller  2105 . In one example, the auto shutdown control system  2300  may be implemented as part of a device manager Finite State Machine (FSM) software implementation executed at the controller  2105 . In the example shown in  FIG.  30   , the auto shutdown control system  2300  includes a dryness detection module  2610 . It should be understood, however, that the auto shutdown control system  2300  may include various other sub-system modules. 
     Referring to  FIG.  30   , the auto shutdown control system  2300 , and more generally the controller  2105 , may identify dry puff conditions at the nicotine e-vaping device  500 , and cause the controller  2105  to control one or more sub-systems of the nicotine e-vaping device  500  to perform one or more consequent actions in response to identifying the dry puff conditions. Dry puff conditions may sometimes be referred to as a dry puff fault or dry puff fault condition. Identification of dry puff conditions may be based on information and/or input such as threshold parameters for the nicotine pod assembly  300 , pod sensor information from one or more pod sensors  2220 , sensor information from one or more sensors  2125  of the device body electrical system  2100 , any combination thereof, or the like. Dry puff conditions are an example of a hard pod fault event at the nicotine e-vaping device  500 . A hard fault pod event is an event that may require corrective action (e.g., replacement of a nicotine pod assembly) to re-enable vaping functions at the nicotine e-vaping device  500 . 
     The controller  2105  may control the one or more sub-systems by outputting one or more control signals (or asserting or de-asserting a respective signal) as will be discussed in more detail later. In some cases, the control signals output from the controller  2105  may be referred to as device power state signals, device power state instructions or device power control signals. In at least one example embodiment, the controller  2105  may output one or more control signals to the heating engine control circuit  2127  to shutdown vaping functions at the nicotine e-vaping device  500  in response to detecting dry puff conditions at the nicotine e-vaping device  500 . 
     According to one or more example embodiments, the type of consequent actions at the nicotine e-vaping device  500  may be based on the dry puff conditions and/or the current operation of the nicotine e-vaping device  500 . Multiple consequent actions may be performed serially in response to a fault event, such as dry puff conditions. In one example, consequent actions may include: 
     (i) an auto-off operation in which the nicotine e-vaping device  500  switches to a low power state (e.g., equivalent to turning the nicotine e-vaping device off using the power button); 
     (ii) a heater-off operation in which power to the heater  336  is cut off or disabled, ending the current puff, but otherwise remaining ready for vaping; or 
     (iii) a vaping-off operation in which the vaping sub-system is disabled (e.g., by disabling all power to the heater  336 ), thereby preventing vaping until a corrective action is taken (e.g., replacing the nicotine pod assembly). 
     As mentioned above, the auto shutdown control system  2300  includes a dryness detection sub-system  2610  (also referred to as a dryness detection sub-system module, circuit or circuitry). Through the dryness detection sub-system  2610 , the controller  2105  monitors the wetness (or dryness) of the wick  338  to detect the presence of dry puff conditions at the nicotine e-vaping device  500 . As mentioned above, when dry puff conditions are detected, the controller  2105  may shutdown or disable one or more sub-systems or elements of the nicotine e-vaping device  500 . 
     In at least one example embodiment, the controller  2105  monitors the wetness of the wick  338  based on a percent change in resistance of the heater  336  over time during vaping. In at least one example embodiment, the controller  2105  may receive one or more signals indicative of a resistance of the heater  336  from the pod temperature measurement circuit  21250 . 
     In another example embodiment, the controller  2105  may calculate the resistance of the heater  336  based on signals from the heater current measurement circuit  21258  and/or the heater voltage measurement circuit  21252 . 
     According to one or more example embodiments, if the percent change in resistance of the heater  336  over a time window exceeds a percent change in resistance threshold, then the controller  2105  determines that dry puff conditions exist (e.g., the wick  338  is dry) at the nicotine e-vaping device  500 . The controller  2105  may obtain the percent change in resistance threshold value from the NVM  2205  in the nicotine pod assembly electrical system  2200 . The percent change in resistance threshold may be set by a manufacturer of the nicotine pod assembly  300  based on empirical data, the nicotine pre-vapor formulation, the construction of the heater  336 , a sub-combination thereof, a combination thereof, or the like. According to at least some example embodiments, the percent change in resistance threshold may be between about 0.1% and 25.5% (in about 0.1% increments). In one example, the percent change in resistance may be about 2.0% for heaters constructed from  316 L grade stainless steel. 
     In one example, dry puff conditions may exist because nicotine pre-vapor formulation is not being supplied to the wick  338  with a sufficient flow rate to maintain a standard temperature profile for the heater  336 . Accordingly, the percent change in resistance may be indicative of a rate of flow of the nicotine pre-vapor formulation to the wick  338 , and the dryness detection sub-system  2610  may be characterized as being configured to determine whether dry puff conditions exist based on the rate of flow of nicotine pre-vapor formulation to the wick  338 . Moreover, dry puff conditions may result from depletion of nicotine pre-vapor formulation in the nicotine pod assembly  300 . Accordingly, detection of dry puff conditions may also be indicative of a depleted and/or empty nicotine pod assembly. 
     The controller  2105  may utilize a sliding measurement window of N samples of resistance of the heater  336  such that the determination is made over a most recent time slice during vaping. This enables the controller  2105  to accommodate relatively long applications of negative pressure by an adult vaper, while also providing for more rapid detections of dry puff conditions, wherein the resistance of the heater  336  begins to change relatively rapidly while negative pressure is applied. 
     In response to detecting dry puff conditions, the controller  2105  may control the heating engine control circuit  2127  to cut-off power to the heater  336  (heater-off) and/or disable vaping at the nicotine e-vaping device  500  (vaping-off). 
     According to at least one example embodiment, a first-in-first-out (FIFO) memory storing about 100 samples (N=100) may be used to set a sliding measurement window of about 100 milliseconds (ms) in which the resistance of the heater  336  is periodically updated (e.g., recalculated) on a 1 ms ‘tick’. The FIFO memory may be internal to the controller  2105  or included in the memory  2130  shown in  FIG.  29   . 
     According to at least some example embodiments, the sliding window may not begin until the resistance measurement of the heater  336  becomes relatively stable, or else spurious values inserted in the FIFO may cause false positives later in the process. The resistance measurement is considered to be relatively stable when the resistance measurement reaches an operating condition where the expected measurement error is less than the percent change in resistance threshold. In one example, the resistance of the heater  336  may become relatively stable once the current flowing through the heater  336  exceeds a ‘wetting’ current threshold (e.g., about 100 milliamps (mA)). The controller  2105  may determine that a ‘wetting’ current threshold has been achieved by monitoring the current through the heater  336  based on signals from the heater current measurement circuit  21258 . 
       FIG.  31    is a flow chart illustrating a dryness detection method according to example embodiments. For example purposes, the flow chart shown in  FIG.  31    will be discussed with regard to the electrical systems shown in  FIG.  29   . It should be understood, however, that example embodiments should not be limited to this example. Rather, example embodiments may be applicable to other nicotine e-vaping devices and electrical systems thereof. Moreover, the example embodiment shown in  FIG.  31    will be described with regard to operations performed by the controller  2105 . However, it should be understood that the example embodiment may be described similarly with regard to the auto shutdown control system  2300  and/or the dryness detection sub-system  2610  performing one or more of the functions/operations shown in  FIG.  31   . 
     Referring to  FIG.  31   , when the nicotine pod assembly  300  is inserted into the device body  100  and the nicotine e-vaping device  500  is powered on, at step S 2702  the controller  2105  obtains the percent change in resistance threshold (also referred to as a percent resistance change parameter) Δ% R_THRESHOLD stored in the NVM  2205  at the nicotine pod assembly electrical system  2200 . 
     At step S 2704 , the controller  2105  determines whether vaping conditions exist at the nicotine e-vaping device  500 . According to at least one example embodiment, the controller  2105  may determine whether vaping conditions exist at the nicotine e-vaping device  500  based on output from the sensor  364 . In one example, if the output from the sensor  364  indicates application of negative pressure above a threshold at the mouthpiece  102  of the nicotine e-vaping device  500 , then the controller  2105  may determine that vaping conditions exist at the nicotine e-vaping device  500 . 
     If the controller  2105  detects vaping conditions at step S 2704 , then at step S 2705  the controller  2105  controls the heating engine control circuit  2127  to apply power to the heater  336  for vaping. Example control of the heating engine control circuit  2127  to apply power to the heater  336  will be discussed in more detail later with regard to  FIGS.  38  and  39   . 
     At step S 2706 , the controller  2105  determines whether the resistance of the heater  336  has stabilized. As mentioned above, the controller  2105  may determine that the resistance of the heater  336  has stabilized once the current through the heater  336  reaches a ‘wetting’ current threshold (e.g., about 100 milliamps (mA)). The controller  2105  may determine that the current through the heater  336  has reached the ‘wetting’ current threshold based on output signals from the heater current measurement circuit  21258 . 
     If the controller  2105  determines that the resistance of the heater  336  has stabilized at step S 2706 , then the controller  2105  begins storing resistance measurements for the heater  336  in the FIFO memory at 1 ms intervals (at a 1 ms ‘tick’). 
     At step S 2710 , the controller  2105  determines whether the FIFO memory is full (e.g., a threshold number of samples have been collected). In one example, the FIFO memory may be full when about 100 samples of the resistance of the heater  336  have been stored (e.g., about 100 ms after the resistance of the heater  336  is determined to have stabilized at step S 2706 ). 
     If the controller  2105  determines that the FIFO memory is full, then at step S 2712  the controller  2105  calculates the percent change in resistance Δ% R between the first resistance value R t_0  (at t 0 ) and a last (most recent) resistance value R t_N-1  (at time t N-1 ) stored in the FIFO memory. 
     At step S 2714 , the controller  2105  compares the calculated percent change in resistance Δ% R with the percent change in resistance threshold Δ% R_THRESHOLD obtained from the NVM  2205  at step S 2702 . 
     If the calculated percent change in resistance Δ% R is greater than the percent change in resistance threshold Δ% R_THRESHOLD, then at step S 2716  the controller  2105  controls the heating engine control circuit  2127  to shutdown (e.g., cut power to) the heater  336 . In one example, the controller  2105  may control the heating engine control circuit  2127  to perform a vaping-off operation. As mentioned above, the vaping-off operation may disable all energy to the heater  336 , thereby preventing vaping until corrective action is taken (e.g., by an adult vaper). As discussed in more detail later, the controller  2105  may control the heating engine control circuit  2127  to disable all energy to the heater  336  by outputting a vaping shutdown signal COIL_SHDN having a logic high level ( FIG.  38   ) and/or by de-asserting (or stopping output of) a vaping enable signal COIL_VGATE_PWM ( FIG.  39   ). In at least one example, at least the vaping enable signal COIL_VGATE_PWM may be a pulse width modulation (PWM) signal. Example corrective action will also be discussed in more detail later. 
     Returning to step S 2714 , if the calculated percent change in resistance Δ% R is less than or equal to the percent change in resistance threshold Δ% R_THRESHOLD, then the process returns to S 2708  and continues as discussed above. 
     Returning to step S 2710 , if the controller  2105  determines that the FIFO memory is not yet full, then the process returns to step S 2708  and continues as discussed above. 
     Returning to step S 2706 , if the controller  2105  determines that the resistance of the heater  336  has not yet stabilized, then the controller  2105  continues to monitor the resistance of the heater  336 . Once the resistance of the heater  336  has stabilized, the process proceeds to step S 2708  and continues as discussed above. 
     Returning to step S 2704 , if the controller  2105  determines that vaping conditions are not yet present, then the controller  2105  continues to monitor output of the sensor  364  for vaping conditions. Once vaping conditions are detected, the process continues as discussed above. 
       FIG.  32    illustrates graphs of resistance versus time when dry puff conditions exist at the start of a puff (‘Dry Puff’), when dry puff conditions occur during a puff (‘Drying Puff’), and when dry puff conditions are not present (‘Standard Puff’). 
     As shown in  FIG.  32   , when dry puff conditions exist at the start of a puff, the resistance increases more sharply over time. In this example, the controller  2105  may shutdown the vaping function of the nicotine e-vaping device  500  at the end of the initial sampling interval (e.g., about 100 ms) because the percent change in resistance Δ% R of the heater  336  at the end of the initial time interval is greater than the percent change in resistance threshold Δ% R_THRESHOLD. 
     When dry puff conditions begin to present during a puff, the heater resistance begins to increase more sharply (the slope of the graph increases). In this case, the controller  2105  shuts down the vaping function at time t SHUTOFF  when the percent change in resistance Δ% R of the heater  336  between the oldest heater resistance and the most recent heater resistance in the FIFO exceeds the percent change in resistance threshold Δ% R_THRESHOLD. 
     When dry puff conditions are not present (standard puff conditions exist), the puff ends and power to the heater  336  is cut-off in response to stopping of application of negative pressure or after expiration of a threshold time interval. In this case, a heater-off operation, rather than a vaping-off operation, may be performed. 
     As mentioned above, dry puff conditions are an example of a hard pod fault event at the nicotine e-vaping device  500 . 
       FIG.  33    is a flow chart illustrating an example method of operation of a nicotine e-vaping device after shutdown of the vaping function (a vaping-off operation) in response to detecting a hard fault pod event, such as dry puff conditions, according to example embodiments. For example purposes, the example embodiment shown in  FIG.  33    will be discussed with regard to dry puff conditions. However, example embodiments should not be limited to this example. 
     Also for example purposes, the flow chart shown in  FIG.  33    will be discussed with regard to the electrical systems shown in  FIG.  29   . It should be understood, however, that example embodiments should not be limited to this example. Rather, example embodiments may be applicable to other nicotine e-vaping devices and electrical systems thereof. Moreover, the example embodiment shown in  FIG.  33    will be described with regard to operations performed by the controller  2105 . However, it should be understood that the example embodiment may be described similarly with regard to the auto shutdown control system  2300  and/or the dryness detection sub-system  2610  performing one or more of the functions/operations shown in  FIG.  33   . 
     Referring to  FIG.  33   , at step S 3804  the controller  2105  logs the occurrence of the dry puff conditions in the memory  2130 . In one example, the controller  2105  may store an identifier of the event (dry puff conditions or a dry puff event) in association with the consequent action (e.g., the vaping-off operation) and the time at which the event and consequent action occurred. 
     At step S 3806 , the controller  2105  controls the vaper indicators  2135  to output an indication that dry puff conditions have been detected. In one example, the indication may be in the form of a sound, visual display and/or haptic feedback to an adult vaper. For example, the indication may be a blinking red LED, a software message containing an error code that is sent (e.g., via Bluetooth) to a connected “App” on a remote electronic device, which may subsequently trigger a notification in the App providing information on a corrective action to the adult vaper, any combination thereof, or the like. 
     At step S 3808 , the controller  2105  determines whether the nicotine pod assembly  300  has been removed (corrective action) from the device body  100  within (prior to expiration of) a removal threshold time interval after (e.g., in response to) indicating the dry puff conditions to the adult vaper. In at least one example embodiment, the controller  2105  may determine that the nicotine pod assembly  300  has been removed from the device body  100  digitally by checking that the set of five contacts  326  of the nicotine pod assembly have been removed. In another example, the controller  2105  may determine that the nicotine pod assembly has been removed from the device body  100  by sensing that the electrical contacts  324   a ,  324   b  and/or  326  of the nicotine pod assembly  300  have been disconnected from the device electrical connector  132  of the device body  100 . In at least one example, the controller  2105  may sense that the electrical contacts  324   a ,  324   b  and/or  326  of the nicotine pod assembly  300  have been disconnected from the device electrical connector  132  of the device body  100  by detecting an infinite resistance between the electrical contacts  324   a ,  324   b  and/or  326  of the nicotine pod assembly  300  and the device electrical connector  132  of the device body  100 . 
     If the controller  2105  determines that the nicotine pod assembly  300  has been removed from the device body  100  within the removal threshold time interval after (e.g., in response to) indicating the dry puff conditions to the adult vaper, then at step S 3814  the controller  2105  controls the nicotine e-vaping device  500  to return to normal operation (a non-fault state). In this case, although energy to the heater  336  is still disabled because the nicotine pod assembly  300  has been removed, the nicotine e-vaping device  500  is otherwise ready to vape in response to application of negative pressure by an adult vaper once a new nicotine pod assembly has been inserted. 
     At step S 3812 , the controller  2105  determines whether a new nicotine pod assembly has been inserted into the device body  100  within (prior to expiration of) an insert threshold time interval after removal of the nicotine pod assembly  300  and returning of the nicotine e-vaping device  500  to normal operation at step S 3814 . In at least one example, the insert threshold time interval may have a length between about 5 minutes and about 120 minutes. The insert threshold time interval may be set to a length within this range by an adult vaper. In at least one example embodiment, the controller  2105  may determine that a new nicotine pod assembly has been inserted into the device body  100  by sensing the resistance of the heater  336  (e.g., between about 0.5 Ohms to about 5.0 Ohms) between the electrical contacts  324   a  and  324   b  of the nicotine pod assembly  300  and the device electrical connector  132  of the device body  100 . In a further example embodiment, the controller  2105  may determine that a new nicotine pod assembly has been inserted into the device body  100  by sensing the presence of a pull-up resistor contained in the nicotine pod assembly  300  between the electrical contacts  326  of the nicotine pod assembly  300  and the device electrical connector  132  of the device body  100 . 
     If the controller  2105  determines that a new nicotine pod assembly has been inserted into the device body  100  within the insert threshold time interval, then at step S 3810  the controller  2105  controls the heating engine control circuit  2127  to re-enable the vaping module (e.g., enable application of power to the heater  336 ). As discussed in more detail later, the controller  2105  may control the heating engine control circuit  2127  to re-enable the vaping module by outputting the vaping shutdown signal COIL_SHDN having a logic low level ( FIG.  38   ) and/or asserting the vaping enable signal COIL_VGATE_PWM ( FIG.  39   ). 
     Returning to step S 3812 , if the controller  2105  determines that a new nicotine pod assembly has not been inserted into the device body  100  within the insert threshold time interval, then at step S 3816  the controller  2105  outputs another one or more control signals to perform an auto-off operation, in which the nicotine e-vaping device  500  is powered off or enters a low-power mode. According to at least some example embodiments, in the context of a normal software auto-off the controller  2105  may output a multitude or plurality of GPIO control lines (signals) to turn off all or substantially all peripherals of the nicotine e-vaping device  500  and cause the controller  2105  to enter a sleep state. 
     Returning now to step S 3808 , if the nicotine pod assembly  300  is not removed within the removal threshold time interval, then the process proceeds to step S 3816  and continues as discussed above. 
       FIG.  34    illustrates an example embodiment of the heater voltage measurement circuit  21252 . 
     Referring to  FIG.  34   , the heater voltage measurement circuit  21252  includes a resistor  3702  and a resistor  3704  connected in a voltage divider configuration between a terminal configured to receive an input voltage signal COIL_OUT and ground. The input voltage signal COIL_OUT is the voltage input to (voltage at the input terminal of) the heater  336 . A node N 3716  between the resistor  3702  and the resistor  3704  is coupled to a positive input of an operational amplifier (Op-Amp)  3708 . A capacitor  3706  is connected between the node N 3716  and ground to form a low-pass filter circuit (an R/C filter) to stabilize the voltage input to the positive input of the Op-Amp  3708 . The filter circuit may also reduce inaccuracy due to switching noise induced by PWM signals used to energize the heater  336 , and have the same phase response/group delay for both current and voltage. 
     The heater voltage measurement circuit  21252  further includes resistors  3710  and  3712  and a capacitor  3714 . The resistor  3712  is connected between node N 3718  and a terminal configured to receive an output voltage signal COIL_RTN. The output voltage signal COIL_RTN is the voltage output from (voltage at the output terminal of) the heater  336 . 
     Resistor  3710  and capacitor  3714  are connected in parallel between node N 3718  and an output of the Op-Amp  3708 . A negative input of the Op-Amp  3708  is also connected to node N 3718 . The resistors  3710  and  3712  and the capacitor  3714  are connected in a low-pass filter circuit configuration. 
     The heater voltage measurement circuit  21252  utilizes the Op-Amp  3708  to measure the voltage differential between the input voltage signal COIL_OUT and the output voltage signal COIL_RTN, and output a scaled heater voltage measurement signal COIL_VOL that represents the voltage across the heater  336 . The heater voltage measurement circuit  21252  outputs the scaled heater voltage measurement signal COIL_VOL to an ADC pin of the controller  2105  for digital sampling and measurement by the controller  2105 . 
     The gain of the Op-Amp  3708  may be set based on the surrounding passive electrical elements (e.g., resistors and capacitors) to improve the dynamic range of the voltage measurement. In one example, the dynamic range of the Op-Amp  3708  may be achieved by scaling the voltage so that the maximum voltage output matches the maximum input range of the ADC (e.g., about 1.8V). In at least one example embodiment, the scaling may be about 267 mV per V, and thus, the heater voltage measurement circuit  21252  may measure up to about 1.8V/0.267V=6.74V. 
       FIG.  35    illustrates an example embodiment of the heater current measurement circuit  21258  shown in  FIG.  29   . 
     Referring to  FIG.  35   , the output voltage signal COIL_RTN is input to a four terminal (4T) measurement resistor  3802  connected to ground. The differential voltage across the four terminal measurement resistor  3802  is scaled by an Op-Amp  3806 , which outputs a heater current measurement signal COIL_CUR indicative of the current through the heater  336 . The heater current measurement signal COIL_CUR is output to an ADC pin of the controller  2105  for digital sampling and measurement of the current through the heater  336  at the controller  2105 . 
     In the example embodiment shown in  FIG.  35   , the four terminal measurement resistor  3802  may be used to reduce error in the current measurement using a ‘Kelvin Current Measurement’ technique. In this example, separation of the current measurement path from the voltage measurement path may reduce noise on the voltage measurement path. 
     The gain of the Op-Amp  3806  may be set to improve the dynamic range of the measurement. In this example, the scaling of the Op-Amp  3806  may be about 0.577 V/A, and thus, the heater current measurement circuit  21258  may measure up to about 
     
       
         
           
             
               
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                 3 
                 . 
                 1 
               
               ⁢ 
               2 
               ⁢ 
               
                   
               
               ⁢ 
               
                 A 
                 . 
               
             
           
         
       
     
     Referring to  FIG.  35    in more detail, a first terminal of the four terminal measurement resistor  3802  is connected to a terminal of the heater  336  to receive the output voltage signal COIL_RTN. A second terminal of the four terminal measurement resistor  3802  is connected to ground. A third terminal of the four terminal measurement resistor  3802  is connected to a low-pass filter circuit (R/C filter) including resistor  3804 , capacitor  3808  and resistor  3810 . The output of the low-pass filter circuit is connected to a positive input of the Op-Amp  3806 . The low-pass filter circuit may reduce inaccuracy due to switching noise induced by the PWM signals applied to energize the heater  336 , and may also have the same phase response/group delay for both current and voltage. 
     The heater current measurement circuit  21258  further includes resistors  3812  and  3814  and a capacitor  3816 . The resistors  3812  and  3814  and the capacitor  3816  are connected to the fourth terminal of the four terminal measurement resistor  3802 , a negative input of the Op-Amp  3806  and an output of the Op-Amp  3806  in a low-pass filter circuit configuration, wherein the output of the low-pass filter circuit is connected to the negative input of the Op-Amp  3806 . 
     The Op-Amp  3806  outputs a differential voltage as the heater current measurement signal COIL_CUR to an ADC pin of the controller  2105  for sampling and measurement of the current through the heater  336  by the controller  2105 . 
     According to at least this example embodiment, the configuration of the heater current measurement circuit  21258  is similar to the configuration of the heater voltage measurement circuit  21252 , except that the low-pass filter circuit including resistors  3804  and  3810  and the capacitor  3808  is connected to a terminal of the four terminal measurement resistor  3802  and the low-pass filter circuit including the resistors  3812  and  3814  and the capacitor  3816  is connected to another terminal of the four terminal measurement resistor  3802 . 
     The controller  2105  may average multiple samples (e.g., of voltage) over a time window (e.g., about 1 ms) corresponding to the ‘tick’ time used in the nicotine e-vaping device  500 , and convert the average to a mathematical representation of the voltage and current across the heater  336  through application of a scaling value. The scaling value may be determined based on the gain settings implemented at the respective Op-Amps, which may be specific to the hardware of the nicotine e-vaping device  500 . 
     The controller  2105  may filter the converted voltage and current measurements using, for example, a three tap moving average filter to attenuate measurement noise. The controller  2105  may then use the filtered measurements to calculate: resistance R HEATER  of the heater  336   
               (       R   HEATER     =       V   HEATER       I   HEATER         )     ,         
power P HEATER  applied to the heater  336 
 
               (       P   HEATER     =       V   HEATER     *     I   HEATER         )     ,         
power supply current
 
               (       I   BATT     =       P   in       V   BATT         )     ,         
where
 
               (       P   in     =       P   HEATER     *     1   Efficiency         )     ,         
or the like. Efficiency is the ratio of power P in  delivered to the heater  336  across all operating conditions. In one example, Efficiency may be at least 85%.
 
     According to one or more example embodiments, the gain settings of the passive elements of the circuits shown in  FIGS.  34  and/or  35    may be adjusted to match the output signal range to the input range of the controller  2105 . 
       FIGS.  36  and  37    illustrate pod temperature measurement circuits according to example embodiments. 
     Referring to  FIG.  36   , the pod temperature measurement circuit  21250 A includes a driver stage  3902 A and a measurement stage  3904 A. The driver stage  3902 A is configured to generate a pod temperature measurement power signal HW_POWER to deliver power to the pod sensor  2220  in response to a pod temperature measurement control signal HW_ENB. The pod temperature measurement power signal HW_POWER may be a PWM signal. The measurement stage  3904 A is configured to generate a pod temperature measurement output signal HW_SIGNAL based on a DAC comparison signal HW_DAC from the DAC (not shown) at the controller  2105  and a pod sensor signal SP_HW from the pod sensor  2220 . The pod temperature measurement output signal HW_SIGNAL may be a differential voltage signal indicative of a temperature of one or more elements of the nicotine pod assembly  300 . Input to and output from an example embodiment of a pod sensor  2220  will be discussed in more detail later. 
     In more detail with regard to  FIG.  36   , the driver stage  3902 A receives the pod temperature measurement control signal HW_ENB from the controller  2105 . In this example, the pod temperature measurement control signal HW_ENB may be a PWM signal having a duty cycle regulated by the controller  2105  to vary power based on the pod sensor signal SP_HW from the pod sensor  2220 . When the pod temperature measurement control signal HW_ENB is asserted (active), the driver stage  3902 A may be enabled and output the pod temperature measurement power signal HW_POWER, otherwise the output of the driver stage  3902 A may be disabled. 
     The pod temperature measurement control signal HW_ENB is input into an enable pin EN of a Low Dropout voltage regulator (LDO) U 10 , which translates the pod temperature measurement control signal HW_ENB, which is a low current drive strength processor signal, into the pod temperature measurement power signal HW_POWER, which is a high current drive strength PWM signal. 
     A resistor R 80  is connected as a pull-down resistor between the enable pin EN of the LDO U 10  and ground to ensure that the output of the driver stage  3902 A is disabled if the pod temperature measurement control signal HW_ENB is in an indeterminate state. 
     The driver stage  3902 A further includes capacitors C 43  and C 44 . Capacitor C 44  is connected to an input pin IN of the LDO U 10  and a voltage source to provide a nicotine reservoir and filter, which may improve the speed at which the pod temperature measurement power signal HW_POWER reaches its ON voltage. The capacitor C 43  is connected between the output pin and ground to provide filtering and a nicotine reservoir for the pod temperature measurement power signal HW_POWER. 
     Resistors R 60  and R 61  form a feedback network  39028  in the form of a voltage divider circuit. The feedback network  39028  outputs a feedback voltage to an adjustment or feedback terminal ADJ of the LDO U 10 . The LDO U 10  sets the precision voltage output of the pod temperature measurement power signal HW_POWER based on the feedback voltage input to the feedback terminal ADJ. According to at least some example embodiments, the relationship between precision voltage output for the pod temperature measurement power signal HW_POWER and the feedback voltage V ADJ  output is given by 
                 V     HW   ⁢           ⁢   _   ⁢           ⁢   POWER       =       V   ADJ     ⁡     (     1   +       R     6   ⁢   1         R     6   ⁢   0           )         .         
In this example, the resistances of resistors R 60  and R 61  have known resistances, and the voltage V ADJ  is also known based on the type of the LDO U 10 .
 
     At the measurement stage  3904 A, the pod sensor signal SP_HW from the pod sensor  2220  is input to the negative input of an Op-Amp U 11 A via resistor R 66  to gain scale the voltage of the pod sensor signal SP_HW for measurement by the ADC at the controller  2105 . The Op-Amp U 11 A is an inverting amplifier with a gain set according to the resistance of resistor R 66  and a resistance of resistor R 67 , which is connected between the negative input and the output of the Op-Amp U 11 A. The capacitor C 47  is connected in parallel with resistor R 67  to form a low-pass filter circuit to filter out high-frequency noise from the pod sensor signal SP_HW. 
     The DAC comparison signal HW_DAC from the DAC at the controller  2105  is input to the positive input of the Op-Amp U 11 A through a voltage divider circuit  39042  including resistors R 63  and R 64 . The DAC comparison signal HW_DAC sets a reference voltage level for the Op-Amp U 11 A, which in effect selects the differential voltage applied to the Op-Amp U 11 A and suppresses or prevents saturation of the Op-Amp U 11 A. In other words, the DAC comparison signal HW_DAC sets an operating point for the Op-Amp U 11 A to suppress saturation of the pod temperature measurement output signal HW_SIGNAL output by the Op-Amp U 11 A. The voltage divider  39042  reduces each DAC step in voltage to provide finer control of the range setting. The ratio of the resistors R 63  and R 64  may approximate the balance resistor and pod sensor  2220  (e.g., at its max temperature). A capacitor C 46  is connected in parallel with the resistor R 64  to form a low-pass filter circuit to filter out noise from the DAC comparison signal HW_DAC. A resistor R 69  is connected between the output of the voltage divider  39042  and the positive input of the Op-Amp U 11 A. 
     The pod sensor signal SP_HW from the pod sensor  2220  may have a relatively small voltage level (e.g., about 2 mV), and thus, the relatively high gain of the Op-Amp U 11 A may be used to match the pod temperature measurement signal HW_SIGNAL to the dynamic signal range of the ADC at the controller  2105  (e.g., about 1.8V). Accordingly, the Op-Amp U 11 A amplifies the pod sensor signal SP_HW and outputs the amplified signal as the pod temperature measurement output signal HW_SIGNAL to the ADC for sampling and measurement at the controller  2105 . 
     Referring to  FIG.  37   , the pod temperature measurement circuit  21250 B includes a driver stage  3902 B and a measurement stage  3904 B. In the example embodiment shown in  FIG.  37   , the driver stage  3902 B and the measurement stage  3904 B are similar to the driver stage  3902 A and the measurement stage  3904 A, respectively, shown in  FIG.  36   , except that the driver stage  3902 B further includes a measurement balancing resistor R 93  and the capacitance of the capacitor C 43  may be reduced in value to increase the rise/fall time of the pod sensor signal SP_HW. In at least one example, the measurement balancing resistor R 93  may have a resistance of about 3 Ohms and may be moved from the nicotine pod assembly electrical system  2200  to the device body assembly electrical system  2100  to reduce cost of the nicotine pod assembly  300 . Additionally, in at least the example embodiment shown in  FIG.  37   , the passive elements may be arranged and adjusted to configure the gain settings such that the output signal range is matched to the input signal range of the controller  2105 . 
       FIG.  38    is a circuit diagram illustrating a heating engine control circuit according to some example embodiments. The heating engine control circuit shown in  FIG.  38    is an example of the heating engine control circuit  2127  shown in  FIG.  29   . 
     Referring to  FIG.  38   , the heating engine control circuit  2127 A includes a CMOS charge pump U 2  configured to supply a power rail (e.g., about 7V power rail (7V_CP)) to one or more gate driver integrated circuits (ICs) to control the power FETs (heater power control circuitry, also referred to as a heating engine drive circuit or circuitry, not shown in  FIG.  38   ) that energize the heater  336  in the nicotine pod assembly  300 . 
     In example operation, the charge pump U 2  is controlled (selectively activated or deactivated) based on the vaping shutdown signal COIL_SHDN (device power state signal; also referred to as a vaping enable signal) from the controller  2105 . In the example shown in  FIG.  38   , the charge pump U 2  is activated in response to output of the vaping shutdown signal COIL_SHDN having a logic low level, and deactivated in response to output of the coil shutdown signal COIL-SHDN having a logic high level. Once the power rail 7V_CP has stabilized after activation of the charge pump U 2  (e.g., after a settling time interval has expired), the controller  2105  may enable the heater activation signal GATE_ON to provide power to the heater power control circuitry and the heater  336 . 
     According to at least one example embodiment, the controller  2105  may perform a vaping-off operation by outputting (enabling) the vaping shutdown signal COIL_SHDN having a logic high level to disable all power to the heater  336  until the vaping shutdown signal COIL_SHDN is disabled (transitioned to a logic low level) by the controller  2105 . 
     The controller  2105  may output the heater activation signal GATE_ON (another device power state signal) having a logic high level in response to detecting the presence of vaping conditions at the nicotine e-vaping device  500 . In this example embodiment, the transistors (e.g., field-effect transistors (FETs)) Q 5  and Q 7 A′ are activated when the controller  2105  enables the heater activation signal GATE_ON to the logic high level. The controller  2105  may output the heater activation signal GATE_ON having a logic low level to disable power to the heater  336 , thereby performing a heater-off operation. 
     If a power stage fault occurs, where the transistors Q 5  and Q 7 A′ are unresponsive to the heater activation signal GATE_ON, then the controller  2105  may perform a vaping-off operation by outputting the vaping shutdown signal COIL_SHDN having a logic high level to cut-off power to the gate driver, which in turn also cuts off power to the heater  336 . 
     In another example, if the controller  2105  fails to boot properly resulting in the vaping shutdown signal COIL_SHDN having an indeterminate state, then the heating engine control circuit  2127 A automatically pulls the vaping shutdown signal COIL_SHDN to a logic high level to automatically cut-off power to the heater  336 . 
     In more detail with regard to  FIG.  38   , capacitor C 9 , charge pump U 2  and capacitor C 10  are connected in a positive voltage doubler configuration. The capacitor C 9  is connected between pins C− and C+ of the charge pump U 2  and serves as a nicotine reservoir for the charge pump U 2 . The input voltage pin VIN of the charge pump U 2  is connected to voltage source BATT at node N 3801 , and capacitor C 10  is connected between ground and the output voltage pin VOUT of the charge pump U 2  at node N 3802 . The capacitor C 10  provides a filter and nicotine reservoir for the output from the charge pump U 2 , which may ensure a more stable voltage output from the charge pump U 2 . 
     The capacitor C 11  is connected between node N 3801  and ground to provide a filter and nicotine reservoir for the input voltage to the charge pump U 2 . 
     Resistor R 10  is connected between a positive voltage source and the shutdown pin SHDN. The resistor R 10  serves as a pull-up resistor to ensure that the input to the shutdown pin SHDN is high, thereby disabling the output (VOUT) of the charge pump U 2  and cutting off power to the heater  336 , when the vaping shutdown signal COIL_SHDN is in an indeterminate state. 
     Resistor R 43  is connected between ground and the gate of the transistor Q 7 A′ at node N 3804 . The resistor R 43  serves as a pull-down resistor to ensure that the transistor Q 7 A′ is in a high impedance (OFF) state, thereby disabling power rail 7V_CP and cutting off power to the heater  336 , if the heater activation signal GATE_ON is in an indeterminate state. 
     Resistor R 41  is connected between node N 3802  and node N 3803  between the gate of the transistor Q 5  and the drain of the transistor Q 7 A′. The resistor R 41  serves as a pull-down resistor to ensure that the transistor Q 5  switches off more reliably. 
     Transistor Q 5  is configured to selectively isolate the power rail 7V_CP from the VOUT pin of charge pump U 2 . The gate of the transistor Q 5  is connected to node N 3803 , the drain of the transistor Q 5  is connected to the output voltage terminal VOUT of the charge pump U 2  at node N 3802 , and the source of the transistor Q 5  serves as the output terminal for the power rail 7V_CP. This configuration allows the capacitor C 10  to reach an operating voltage more quickly by isolating the load, and creates a fail-safe insofar as the vaping shutdown signal COIL_SHDN and heater activation signal GATE_ON must both be in the correct state to provide power to the heater  336 . 
     Transistor Q 7 A is configured to control operation of the transistor Q 5  based on the heater activation signal GATE_ON. For example, when the heater activation signal GATE_ON is logic high level (e.g., above ˜2V), the transistor Q 7 A in is in its low impedance (ON) state, which pulls the gate of the transistor Q 5  to ground thereby resulting in the transistor Q 5  transitioning to a low impedance (ON) state. In this case, the heating engine control circuit  2127 A outputs the power rail 7V_CP to the heating engine drive circuit (not shown), thereby enabling power to the heater  336 . 
     If the heater activation signal GATE_ON has a logic low level, then transistor Q 7 A transitions to a high impedance (OFF) state, which results in discharge of the gate of the transistor Q 5  through resistor R 41 , thereby transitioning the transistor Q 5  into a high impedance (OFF) state. In this case, the power rail 7V_CP is not output and power to the heating engine drive circuit (and heater  336 ) is cut-off. 
     In the example shown in  FIG.  38   , since the transistor Q 5  requires a gate voltage as high as the source voltage (˜7V) to be in the high impedance (OFF) state, the controller  2105  does not control the transistor Q 5  directly. The transistor Q 7 A provides a mechanism for controlling the transistor Q 5  based on a lower voltage from the controller  2105 . 
       FIG.  39    is a circuit diagram illustrating another heating engine control circuit according to example embodiments. The heating engine control circuit shown in  FIG.  39    is another example of the heating engine control circuit  2127  shown in  FIG.  29   . 
     Referring to  FIG.  39   , the heating engine control circuit  2127 B includes a rail converter circuit  39020  (also referred to as a boost converter circuit) and a gate driver circuit  39040 . The rail converter circuit  39020  is configured to output a voltage signal 9V_GATE (also referred to as a power signal or input voltage signal) to power the gate driver circuit  39040  based on the vaping enable signal COIL_VGATE_PWM (also referred to as a vaping shutdown signal). The rail converter circuit  39020  may be software defined, with the vaping enable signal COIL_VGATE_PWM used to regulate the 9V_GATE output. 
     The gate driver circuit  39040  utilizes the input voltage signal 9V_GATE from the rail converter circuit  39020  to drive the heating engine drive circuit  3906 . 
     In the example embodiment shown in  FIG.  39   , the rail converter circuit  39020  generates the input voltage signal 9V_GATE only if the vaping enable signal COIL_VGATE_PWM is asserted (present). The controller  2105  may disable the 9V rail to cut power to the gate driver circuit  39040  by de-asserting (stopping or terminating) the vaping enable signal COIL_VGATE_PWM. Similar to the vaping shutdown signal COIL_SHDN in the example embodiment shown in  FIG.  38   , the vaping enable signal COIL_VGATE_PWM may serve as a device state power signal for performing a vaping-off operation at the nicotine e-vaping device  500 . In this example, the controller  2105  may perform a vaping-off operation by de-asserting the vaping enable signal COIL_VGATE_PWM, thereby disabling all power to the gate driver circuit  39040 , heating engine drive circuit  3906  and heater  336 . The controller  2105  may then enable vaping at the nicotine e-vaping device  500  by again asserting the vaping enable signal COIL_VGATE_PWM to the rail converter circuit  39020 . 
     Similar to the heater activation signal GATE_ON in  FIG.  38   , the controller  2105  may output the first heater enable signal GATE_ENB having a logic high level to enable power to the heating engine drive circuit  3906  and the heater  336  in response to detecting vaping conditions at the nicotine e-vaping device  500 . The controller  2105  may output the first heater enable signal GATE_ENB having a logic low level to disable power to the heating engine drive circuit  3906  and the heater  336 , thereby performing a heater-off operation. 
     Referring in more detail to the rail converter circuit  39020  in  FIG.  39   , a capacitor C 36  is connected between the voltage source BATT and ground. The capacitor C 36  serves as a nicotine reservoir for the rail converter circuit  39020 . 
     A first terminal of inductor L 1006  is connected to node Node 1  between the voltage source BATT and the capacitor C 36 . The inductor L 1006  serves as the main storage element of the rail converter circuit  39020 . 
     A second terminal of the inductor L 1006 , a drain of a transistor (e.g., an enhancement mode MOSFET) Q 1009  and a first terminal of a capacitor C 1056  are connected at node Node 2 . The source of the transistor Q 1009  is connected to ground, and the gate of the transistor Q 1009  is configured to receive the vaping enable signal COIL_VGATE_PWM from the controller  2105 . 
     In the example shown in  FIG.  39   , the transistor Q 1009  serves as the main switching element of the rail converter circuit  39020 . 
     A resistor R 29  is connected between the gate of the transistor Q 1009  and ground to act as a pull-down resistor to ensure that transistor Q 1009  switches off more reliably and that operation of the heater  336  is prevented when the vaping enable signal COIL_VGATE_PWM is in an indeterminate state. 
     A second terminal of the capacitor C 1056  is connected to a cathode of a Zener diode D 1012  and an anode of a Zener diode D 1013  at node Node 3 . The anode of the Zener diode D 1012  is connected to ground. 
     The cathode of the Zener diode D 1013  is connected to a terminal of the capacitor C 35  and an input of a voltage divider circuit including resistors R 1087  and R 1088  at node Node 4 . The other terminal of the capacitor C 35  is connected to ground. The voltage at node Node 4  is also the output voltage 9V_GATE output from the rail converter circuit  39020 . 
     A resistor R 1089  is connected to the output of the voltage divider circuit at node Node 5 . 
     In example operation, when the vaping enable signal COIL_VGATE_PWM is asserted and at a logic high level, the transistor Q 1009  switches to a low impedance state (ON), thereby allowing current to flow from the voltage source BATT and capacitor C 36  to ground through inductor L 1006  and transistor Q 1009 . This stores energy in inductor L 1006 , with the current increasing linearly over time. 
     When the vaping enable signal COIL_VGATE_PWM is at a logic low level, the transistor Q 1009  switches to a high impedance state (OFF). In this case, the inductor L 1006  maintains current flow (decaying linearly), and the voltage at node Node 2  rises. 
     The duty cycle of the vaping enable signal COIL_VGATE_PWM determines the amount of voltage rise for a given load. Accordingly, the vaping enable signal COIL_VGATE_PWM is controlled by the controller  2105  in a closed loop using feedback signal COIL_VGATE_FB output by the voltage divider circuit at node Node 5  as feedback. The switching described above occurs at a relatively high rate (e.g., about 2 MHz, however different frequencies may be used depending on the parameters required and element values). 
     Still referring to the rail converter circuit  39020  in  FIG.  39   , the capacitor C 1056  is an AC coupling capacitor that provides a DC block to remove the DC level. The capacitor C 1056  blocks current flow from voltage source BATT through the inductor L 1006  and the diode D 1013  to the gate driver circuit  39040  when the vaping enable signal COIL_VGATE_PWM is low to save battery life (e.g., when the nicotine e-vaping device  500  is in a standby mode). The capacitance of the capacitor C 1056  may be chosen to provide a relatively low impedance path at the switching frequency. 
     The Zener diode D 1012  establishes the ground level of the switching signal. Since capacitor C 1056  removes the DC level, the voltage at node Node 3  may normally be bipolar. In one example, the Zener diode D 1012  may clamp the negative half cycle of the signal to about 0.3V below ground. 
     The capacitor C 35  serves as the output nicotine reservoir for the rail converter circuit  39020 . The Zener diode D 1013  blocks current from the capacitor C 35  from flowing through capacitor C 1056  and transistor Q 1009  when the transistor Q 1009  is ON. 
     As the decaying current from inductor L 1006  creates a voltage rise at node Node 4  between Zener diode D 1013  and capacitor C 35 , current flows into capacitor C 35 . The capacitor C 35  maintains the 9V_GATE voltage while energy is being stored in the inductor L 1006 . 
     The voltage divider circuit including resistors R 1087  and R 1088  reduces the voltage to an acceptable level for measurement at the ADC at the controller  2105 . This reduced voltage signal is output as the feedback signal COIL_VGATE_FB. 
     In the circuit shown in  FIG.  39   , the feedback signal COIL_VGATE_FB voltage is scaled at about 0.25×, therefore the 9V output voltage is reduced to about 2.25V for input to the ADC at the controller  2105 . 
     The resistor R 1089  provides a current limit for an over-voltage fault at the output of the rail converter circuit  39020  (e.g., at node Node 4 ) to protect the ADC at the controller  2105 . 
     The 9V output voltage signal 9V_GATE is output from the rail converter circuit  39020  to the gate driver circuit  39040  to power the gate driver circuit  39040 . 
     Referring now to the gate driver circuit  39040  in more detail, the gate driver circuit  39040  includes, among other things, an integrated gate driver U 2003  configured to convert low-current signal(s) from the controller  2105  to high-current signals for controlling switching of the transistors (e.g., MOSFETs) of the heating engine drive circuit  3906 . The integrated gate driver U 2003  is also configured to translate voltage levels from the controller  2105  to voltage levels required by the transistors of the heating engine drive circuit  3906 . In the example embodiment shown in  FIG.  39   , the integrated gate driver U 2003  is a half-bridge driver. However, example embodiments should not be limited to this example. 
     In more detail, the 9V output voltage from the rail converter circuit  39020  is input to the gate driver circuit  39040  through a filter circuit including resistor R 2012  and capacitor C 2009 . The filter circuit including the resistor R 2012  and the capacitor C 2009  is connected to the VCC pin (pin 4) of the integrated gate driver U 2003  and the anode of Zener diode  52002  at node Node 6 . The second terminal of the capacitor C 2009  is connected to ground. The anode of the Zener diode D 2002  is connected to a first terminal of capacitor C 2007  and a boost pin BST (pin 1) of the integrated gate driver U 2003  at node Node 7 . A second terminal of the capacitor C 2007  is connected to the switching node pin SWN (pin 7) of the integrated gate driver U 2003  and the heating engine drive circuit  3906  (e.g., between two MOSFETs) at node Node 8 . In the example embodiment shown in  FIG.  39   , the Zener diode D 2002  and the capacitor C 2007  form part of a boot-strap charge-pump circuit connected between the input voltage pin VCC and the boost pin BST of the integrated gate driver U 2003 . Because the capacitor C 2007  is connected to the 9V input voltage signal 9V_GATE from the rail converter circuit  39020 , the capacitor C 2007  charges to a voltage almost equal to the voltage signal 9V_GATE through the diode D 2002 . 
     Still referring to  FIG.  39   , a high side gate driver pin DRVH (pin 8), a low side gate driver pin DRVL (pin 5) and an EP pin (pin 9) of the integrated gate driver U 2003  are also connected to the heating engine drive circuit  3906 . 
     A resistor R 2013  and a capacitor C 2010  form a filter circuit connected to the input pin IN (pin 2) of the integrated gate driver U 2003 . The filter circuit is configured to remove high frequency noise from the second heater enable signal COIL_Z input to the input pin. The second heater enable signal COIL_Z may be a PWM signal from the controller  2105 . 
     A resistor R 2014  is connected to the filter circuit and the input pin IN at node Node 9 . The resistor R 2014  is used as a pull-down resistor, such that if the second heater enable signal COIL_Z is floating (or indeterminate), then the input pin IN of the integrated gate driver U 2003  is held at a logic low level to prevent activation of the heating engine drive circuit  3906  and the heater  336 . 
     The first heater enable signal GATE_ENB from the controller  2105  is input to the OD pin (pin 3) of the integrated gate driver U 2003 . A resistor R 2016  is connected to the OD pin of the integrated gate driver U 2003  as a pull-down resistor, such that if the first heater enable signal GATE_ENB from the controller  2105  is floating (or indeterminate), then the OD pin of the integrated gate driver U 2003  is held at a logic low level to prevent activation of the heating engine drive circuit  3906  and the heater  336 . 
     In the example embodiment shown in  FIG.  39   , the heating engine drive circuit  3906  includes a transistor (e.g., a MOSFET) circuit including transistors (e.g., MOSFETs)  39062  and  39064  connected in series between the voltage source BATT and ground. The gate of the transistor  39064  is connected to the low side gate driver pin DRVL (pin 5) of the integrated gate driver U 2003 , the drain of the transistor  39064  is connected to the switching node pin SWN (pin 7) of the integrated gate driver U 2003  at node Node 8 , and the source of the transistor  39064  is connected to ground GND. 
     When the low side gate drive signal output from the low side gate driver pin DRVL is high, the transistor  39064  is in a low impedance state (ON), thereby connecting the node Node 8  to ground. 
     As mentioned above, because the capacitor C 2007  is connected to the 9V input voltage signal 9V_GATE from the rail converter circuit  39020 , the capacitor C 2007  charges to a voltage equal or substantially equal to the 9V input voltage signal 9V_GATE through the diode D 2002 . 
     When the low side gate drive signal output from the low side gate driver pin DRVL is low, the transistor  39064  switches to the high impedance state (OFF), and the high side gate driver pin DRVH (pin 8) is connected internally to the boost pin BST within the integrated gate driver U 2003 . As a result, transistor  39062  is in a low impedance state (ON), thereby connecting the switching node SWN to the voltage source BATT to pull the switching node SWN (Node 8) to the voltage of the voltage source BATT. 
     In this case, the node Node 7  is raised to a boost voltage V(BST)≈V(9V_GATE)+V(BATT), which allows the gate-source voltage of the transistor  39062  to be the same or substantially the same as the voltage of the 9V input voltage signal 9V_GATE (e.g., V(9V_GATE)) regardless (or independent) of the voltage from the voltage source BATT. As a result, the switching node SWN (Node 8) provides a high current switched signal that may be used to generate a voltage output to the heater  336  that is substantially independent of the voltage output from the battery voltage source BATT. 
       FIGS.  40  and  41    illustrate example embodiments of temperature sensing transducers included in the pod sensors  2220  shown in  FIG.  29   . 
     Referring to  FIG.  40   , the temperature sensing transducer  3600 A includes a resistor R 3602  and a sensor transducer R 3604 . In at least one example embodiment the resistor R 3602  may have a fixed resistance of about 3 Ohms. The sensor transducer R 3604  may be a resistor having a variable resistance that varies with temperature. The resistor R 3602  and the sensor transducer R 3604  are arranged in a voltage divider circuit so that the voltage across the sensor transducer R 3604  (voltage at measurement node N 3606 ) may be output to the pod temperature measurement circuit  21250  for scaling and then use in measuring the temperature of the nicotine pod assembly  300  or one or more elements of the nicotine pod assembly  300 . 
     In example operation, a driver stage  3902 A of the pod temperature measurement circuit  21250 A ( FIG.  36   ) applies a pod temperature measurement power signal HW_POWER to the temperature sensing transducer  3600 A and a measurement stage  3904 A of the pod temperature measurement circuit  21250 A scales the sensed voltage of the pod sensor signal SP_HW at the measurement node N 3606 , and outputs the scaled voltage to the controller  2105  as the pod temperature measurement output signal HW_SIGNAL. The controller  2105  then determines the temperature of the nicotine pod assembly  300  or one or more elements of the nicotine pod assembly  300  based on the pod temperature measurement output signal HW_SIGNAL. 
     In at least one example embodiment, the voltage of the pod temperature measurement power signal HW_POWER may be fixed, and thus, the pod temperature measurement circuit  21250 A may also calculate the current through resistors R 3602  and R 3604  because the resistance of the resistor R 3602  is a known resistance. 
     Referring to the example embodiment shown in  FIG.  41   , the temperature sensing transducer  3600 B is similar to the temperature sensing transducer  3600 A in  FIG.  40   , except that, as mentioned above with regard to  FIG.  37   , the resistor R 3602  is omitted from the temperature sensing transducer  3600 B and relocated to the driver stage  3902 B of the pod temperature measurement circuit  21250 B in  FIG.  37   . By relocating the resistor R 3602  to the driver stage  3902 B of the pod temperature measurement circuit  21250 B, the cost of the nicotine pod assembly electrical system  2200  and/or the number of pins required for the interface between the device body  100  and the nicotine pod assembly  300  may be reduced. Moreover, the resistance of the sensor transducer R 3606  in the example embodiment shown in  FIG.  41    may be larger than the resistance of the sensor transducer R 3604  in  FIG.  40    to reduce current consumption by the temperature sensing transducer  3600 B. 
     Example embodiments have been disclosed herein, however, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.