U.S. patent application number 16/197618 was filed with the patent office on 2019-08-29 for cordless curling iron and wand.
This patent application is currently assigned to Lunata Inc.. The applicant listed for this patent is Lunata Inc.. Invention is credited to Monica Abramov, Anastassia Boguslavskaya.
Application Number | 20190261757 16/197618 |
Document ID | / |
Family ID | 67685350 |
Filed Date | 2019-08-29 |
![](/patent/app/20190261757/US20190261757A1-20190829-D00000.png)
![](/patent/app/20190261757/US20190261757A1-20190829-D00001.png)
![](/patent/app/20190261757/US20190261757A1-20190829-D00002.png)
![](/patent/app/20190261757/US20190261757A1-20190829-D00003.png)
![](/patent/app/20190261757/US20190261757A1-20190829-D00004.png)
United States Patent
Application |
20190261757 |
Kind Code |
A1 |
Abramov; Monica ; et
al. |
August 29, 2019 |
CORDLESS CURLING IRON AND WAND
Abstract
A cordless hair care appliance easily convertible between a
curling wand and a curling iron. The appliance features a removable
clamp formed as a ring portion and hinged clamp, where the ring
portion slidably fits onto the barrel of the curling wand. The
appliance has an enlarged diameter portion at the interface between
the barrel and a main body. The removable clamp is friction fit to
the barrel when slid into place at the interface. The appliance may
operate by battery alone or using battery plus a DC current
supplied by a corded AC adaptor. An internal processing unit
manages power usage and determines whether the device is operating
in battery mode or corded mode.
Inventors: |
Abramov; Monica; (Concord,
CA) ; Boguslavskaya; Anastassia; (Toronto,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lunata Inc. |
Concord |
|
CA |
|
|
Assignee: |
Lunata Inc.
Concord
CA
|
Family ID: |
67685350 |
Appl. No.: |
16/197618 |
Filed: |
November 21, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62636295 |
Feb 28, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A45D 2/2464 20130101;
A45D 2/30 20130101; A45D 2001/045 20130101; A45D 1/04 20130101 |
International
Class: |
A45D 2/24 20060101
A45D002/24; A45D 2/30 20060101 A45D002/30; A45D 1/04 20060101
A45D001/04 |
Claims
1. A hair care appliance, comprising: a main body housing
electrical components, including a battery and a processing unit; a
barrel attached to and extending from the main body and having a
heat conductive exterior surface, the barrel having an outer
diameter, wherein an interface between the main body and the barrel
includes an enlarged diameter portion axially aligned with the
barrel and having an exterior surface diameter greater than the
outer diameter; and removable clamp having a ring portion sized to
slidably fit over the barrel and, on an outer face of the ring
portion, a hinged clamp extending in an axial direction along the
barrel and spring-biased to be urged against the barrel, wherein
the ring portion has an inner diameter sized to friction fit when
slid along the barrel to the enlarged diameter portion.
2. The hair care appliance of claim 1, wherein the enlarged
diameter portion comprises a frustoconically-shaped outer surface
having a narrow-diameter end attached to the barrel and matching
the outer diameter of the barrel, and having a wide-diameter end
attached to the main body.
3. The hair care appliance of claim 2, wherein the inner diameter
of the ring portion is greater than the outer diameter of the
barrel and less than the wide-diameter end of the enlarged diameter
portion, such that the ring portion friction fits on the
frustoconically-shaped outer surface of the enlarged diameter
portion.
4. The hair care appliance of claim 1, wherein the barrel includes
an annular groove in its exterior surface proximate the
interface.
5. The hair care appliance of claim 4, wherein the enlarged
diameter portion includes a retaining ring disposed within the
annular groove, the retaining ring having a thickness such that its
outer surface has a diameter larger than the outer diameter of the
barrel when the retaining ring is disposed within the annular
groove.
6. The hair care appliance of claim 4, wherein the ring portion has
an inner surface in contact with the exterior surface of the
barrel, and wherein the inner surface includes a protuberance sized
to snap-fit into the annular groove.
7. The hair care appliance of claim 6, wherein the protuberance
includes at least one of a rib or a boss.
8. The hair care appliance of claim 1, wherein the hinged clamp is
formed from a heat conductive material such that the hinged clamp
becomes heated when the barrel is heated.
9. The hair care appliance of claim 8, wherein the ring portion
further includes a lever connected to the hinged clamp and
extending in a direction opposite from the hinged clamp, the lever
being depressable against a bias spring to pivot the hinged clamp
apart from the barrel.
10. The hair care appliance of claim 9, wherein the lever includes
a heat-insulated thumb pad.
11. The hair care appliance of claim 1, wherein an outer surface of
the barrel proximate the interface includes one of a projection or
a groove and wherein an inner surface of the ring portion includes
a corresponding one of a groove or a projection, respectively, that
engages said one of the projection or the groove on the outer
surface of the barrel when the ring portion is slidably positioned
at the interface so as to prevent rotation of the ring portion, in
use.
12. The hair care appliance of claim 1, wherein the removable clamp
includes a heat-insulated stand on a side of the ring portion
opposite the hinged clamp, to support the hair care appliance with
the barrel elevated when resting on a surface.
13. The hair care appliance of claim 12, wherein the heat-insulated
stand includes a projecting structure having at least two
projection points extending outwards from the ring portion in a
direction substantially away from the side of the ring portion to
which the hinged clamp is attached.
14. The hair care appliance of claim 1, further including a DC
voltage plug socket for receiving a DC current supply, a heating
element for converting electrical current to heat for heating the
barrel, and a digital potentiometer for regulating the power
supplied to the heating element under control of the processing
unit.
15. The hair care appliance of claim 14, further including a
charging circuit for charging the battery from the DC current
supply received via the DC voltage plug socket.
16. The hair care appliance of claim 14, wherein the processing
unit is to determine whether the DC current supply is connected to
the DC voltage plug socket and, if so, to supply current to the
heating element from both the battery and the DC current supply
when heating the heating element.
17. A hair care appliance, comprising: a main body housing
electrical components, including a battery and a processing unit; a
barrel attached to and extending from the main body and having a
heat conductive exterior surface, the barrel having an outer
diameter, wherein an interface between the main body and the barrel
includes an enlarged diameter portion axially aligned with the
barrel and having an exterior surface diameter greater than the
outer diameter; removable clamp having a ring portion sized to
slidably fit over the barrel and, on an outer face of the ring
portion, a hinged clamp extending in an axial direction along the
barrel and spring-biased to be urged against the barrel; and
retention means for resisting axial movement of the removable clamp
when slid onto the barrel to a point proximate the interface.
18. The hair care appliance claimed in claim 17, wherein the
retention means includes friction fit means for causing friction
between the ring portion and the barrel so as to resist axial
movement of the ring portion once at the point.
19. The hair care appliance claimed in claim 18, wherein the
retention means further resists rotational movement of the ring
portion when the ring portion is positioned at the point.
Description
FIELD
[0001] The present application generally relates to hair care
appliances and, in particular, to a cordless curling iron that
easily converts into a curling wand.
BACKGROUND
[0002] Curling irons are common hair care appliances. Most curling
irons are corded, since the heating element draws a high current
and needs a significant power source. Attempts have been made to
produce cordless curling irons that are butane-powered, but these
often fail to achieve a high enough temperature to be useful.
Gas-powered curling irons are also considered more inherently
dangerous and would be prohibited in some situations, such as on
airplanes.
[0003] Another common hair care appliance is a curling wand.
Individuals or hair care professionals typically have both a
curling iron and a curling wand since each appliance is used to
achieve a different stylistic effect. When traveling, this means
that both appliances must be carried if a full range of hair
styling options is desired.
[0004] It would be advantageous to provide for an improved cordless
hair care appliance that, at least in part, addresses some of the
shortcomings of existing hair care appliances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Reference will now be made, by way of example, to the
accompanying drawings which show example embodiments of the present
application, and in which:
[0006] FIG. 1 shows a perspective view of one example embodiment of
a hair care appliance configured to operate in a curling wand
mode;
[0007] FIG. 2 shows the hair care appliance of FIG. 1 in a
partially-exploded view;
[0008] FIG. 3 shows a perspective view of another example
embodiment of a hair care appliance in a partially-exploded view;
and
[0009] FIG. 4 shows, in block diagram form, one example of the
electrical components of an embodiment of the hair care
appliance.
[0010] Similar reference numerals may have been used in different
figures to denote similar components.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0011] Various examples and aspects of the present application will
be described with reference to the details discussed herein. The
following description and drawings are illustrative of the present
application and are not to be construed as limiting the present
application. Numerous details are described to provide a thorough
understanding of various embodiments. However, in certain
instances, well-known or conventional details are not described in
order to provide a concise discussion of the embodiments of the
present application. It will also be appreciated that various
aspects and features may be implemented in sub-combinations, and
that an aspect or feature from one described embodiment may be
incorporated into other described embodiments.
[0012] The present application describes, in some examples, a
battery-powered hair care appliance that functions as both a
curling iron and a curling wand. A removable clamp on a ring may be
slid onto or off of the barrel to convert the appliance between
iron and wand.
[0013] In one aspect, the present application describes a hair care
appliance that includes a main body housing electrical components,
including a battery and a processing unit. The appliance includes a
barrel attached to and extending from the main body and having a
heat conductive exterior surface, the barrel having an outer
diameter, wherein an interface between the main body and the barrel
includes an enlarged diameter portion axially aligned with the
barrel and having an exterior surface diameter greater than the
outer diameter, and removable clamp having a ring portion sized to
slidably fit over the barrel and, on an outer face of the ring
portion, a hinged clamp extending in an axial direction along the
barrel and spring-biased to be urged against the barrel. The ring
portion has an inner diameter sized to friction fit when slid along
the barrel to the enlarged diameter portion.
[0014] In another aspect, the present application describes a hair
care appliance that includes a main body housing electrical
components, including a battery and a processing unit; a barrel
attached to and extending from the main body and having a heat
conductive exterior surface, the barrel having an outer diameter,
wherein an interface between the main body and the barrel includes
an enlarged diameter portion axially aligned with the barrel and
having an exterior surface diameter greater than the outer
diameter; removable clamp having a ring portion sized to slidably
fit over the barrel and, on an outer face of the ring portion, a
hinged clamp extending in an axial direction along the barrel and
spring-biased to be urged against the barrel; and retention means
for resisting axial movement of the removable clamp when slid onto
the barrel to a point proximate the interface.
[0015] Other aspects and features of the present application will
be understood by those of ordinary skill in the art from a review
of the following description of examples in conjunction with the
accompanying figures.
[0016] In the present application, the terms "comprises" and
"comprising" are intended to be inclusive and open ended, and not
exclusive. Specifically, when used in the specification and claims,
the terms "comprises" and "comprising" and variations thereof mean
the specified features, steps, or components are included. These
terms are not to be interpreted to exclude the presence of other
features, steps, or components.
[0017] In the present application, the term "exemplary" means
"serving as an example, instance, or illustration", and should not
be construed as preferred or advantageous over other configurations
disclosed herein.
[0018] In the present application, the terms "about",
"approximately", and "substantially" are meant to cover variations
that may exist in the upper and lower limits of the ranges of
values, such as variations in properties, parameters, and
dimensions. In a non-limiting example, the terms "about",
"approximately", and "substantially" may mean plus or minus 10
percent or less.
[0019] In the present application, the term "and/or" is intended to
cover all possible combinations and sub-combinations of the listed
elements, including any one of the listed elements alone, any
sub-combination, or all of the elements, and without necessarily
excluding additional elements.
[0020] In the present application, the phrase "at least one of . .
. or . . . " is intended to cover any one or more of the listed
elements, including any one of the listed elements alone, any
sub-combination, or all of the elements, without necessarily
excluding any additional elements, and without necessarily
requiring all of the elements.
[0021] There are a number of hair care appliances used to style
hair, including curling irons, curling wands, and hair
straighteners, among others. Both curling irons and curling wands
features a cylindrical heated barrel, but the curling iron further
includes a clamp to press locks of hair against the barrel,
allowing for tighter curls to be imparted to the locks.
Straighteners feature flat-surfaced heated jaws between which locks
of hair can be clamped in order to remove curl. All three of these
examples contain heating elements that cause a heat-conductive
portion of the appliance to become hot during use. To power the
heating element, these devices tend to draw large currents and rely
on a corded power connection to conventional power outlets.
Moreover, each device is designed for a different purpose and those
users that which to achieve different hair care looks typically own
at least one of each of these devices.
[0022] In accordance with one aspect of the present application, a
hair care appliance is provided that functions as both a curling
iron and a curling wand and is easily converted between iron and
wand modes of operation.
[0023] In another aspect of the present application, a hair care
appliance is provided that operates in both battery-powered and
wall-plug powered modes. In particular, in some implementations,
the wall-plug is a DC power supply, such as through a plug-in AC/DC
adaptor. This DC power supply is sufficient to recharge the
internal battery over time, but insufficient to power the hair care
heating element on its own. In some instances, the DC power supply
comes from a USB-connection or some other similar DC current
source, as opposed to an AC/DC adaptor plugged into the power
mains.
[0024] Accordingly, when plugged in to the DC power supply, the
heating element draws current from both the DC power supply and the
internal battery when heating. When not heating the element, the DC
power supply recharges the internal battery. In some embodiments,
an internal power sensor determines whether the appliance is
receiving power via a DC power supply and, if not, then it relies
solely on battery power for heating the appliance and, otherwise,
relies on both the DC power supply and the internal battery for
current to heat the heating element.
[0025] Reference is now made to FIG. 1, which shows one example of
a hair care appliance 10. The appliance 10 features a generally
cylindrical main body 12 and an axially-aligned generally
cylindrical barrel 14. The main body 12 serves as a handle and
houses the battery, a processing unit, and associated circuitry.
The barrel 14 is formed from a heat-conductive metal, whereas the
main body 12 may be formed from a generally heat-insulated material
so that the heat generated by a heating element does not heat the
main body 12.
[0026] The main body 12 may include user interface elements, such
as an input device 16 and a display device 18. In this example, the
display device 18 includes at least a numeric display for
indicating a temperature setting or reading. The input device 16 in
this example includes a power on/off button 20, a temperature up
button 22 and a temperature down button 24. The display device 18
may alternatively or additionally include other display elements
such as LED lights for indicate modes of operation or other state
information. In some instances, LED lights may be incorporated into
the main body 12. In some instances, LED lights may be incorporated
into the input device 16. For example the input device 16 or a
portion of it may be illuminated. The colour of illumination may
signal a state or mode of operation. For example, a particular
colour, such as green, illuminating the power button 20 may signal
that the appliance 10 is turned on. The LED lights may be pulsed or
flash to signal other state or mode information, such as if the
battery is being charged, or to signal a low battery state, or
other such information.
[0027] The main body 12 may include an end cap 24 that is generally
circular. The end cap may be friction fit, screwed in, or otherwise
attached so as to secure the end of the main body 12 and retain one
or more rechargeable batteries within an internal battery
compartment (not illustrated). In one example implementation the
battery may be a 3.7V 5000 mAh rechargeable and replaceable
battery.
[0028] The main body 12 further includes a plug socket (not shown)
for receiving a connector from an AC/DC adapter. The AC/DC adapter
plugs into a wall socket and supplies DC power via its connector.
The connector may be a coaxial connector in some examples. The DC
power supplied by the AC adapter may be, for example, 9 Volts DC,
although other implementations may use different voltage levels. In
one example, a USB connector is used and 5 VDC is supplied via the
USB connection. In yet another example, a USB connector is used to
obtain higher power (and higher voltage) in compliance with the USB
Power Deliver Specification revision 3.0.
[0029] The hair care appliance 10 further includes a removable
clamp 30. The removable clamp includes a ring portion 32 and a
hinged clamp 34 pivotably mounted to the ring portion 32. The
hinged clamp 34 extends in an axial direction parallel to the
barrel 14 and is spring-biased at the hinged area to urge the
hinged clamp 34 against the outer surface of the barrel 14. The
removable clamp 30 includes a lever 36 connected to the hinged
clamp 34 and extending away from the hinged clamp 34. The lever 36
is positioned so as to be thumb-depressible in opposition go the
spring-biasing, thereby pivoting the hinged clamp 34 up and away
from the outer surface of the barrel 14.
[0030] The hinged clamp 34 may be constructed from a
heat-conductive material such that heat generated for heating the
barrel 14 is conductively transferred to the hinged clamp 34 when
the hinged clamp 34 is in contact with the barrel 14. The lever 36
may be made, at least in part, from a non-heat-conductive material
so that it does not heat up and can be touched by a user. The ring
portion 32 may be made from head-conductive material,
non-heat-conductive material, or a combination thereof.
[0031] Reference is now also made to FIG. 2, which shows the
example hair care appliance 10 in exploded view. In this view, the
removable clamp 30 is slid off the barrel 14. With the removable
clamp 30 detached from the barrel 14, the appliance 10 may function
as a curling wand, whereas with the removable clamp 30 attached it
functions as a curling iron.
[0032] In some embodiments, the removable clamp 30 may incorporate
a stand for the appliance 10. That is, the ring portion 32 may
include a non-heat-conductive stand 40, formed as a projection from
its underside. The projection may be a two-point projection with or
without a relatively flat portion interconnecting the two-points.
The projection extends from the outer surfaces of the ring portion
32 on a side opposite to the side of the ring portion 32 to which
the hinged clamp 34 is pivotably attached.
[0033] In this example, the barrel 14 and the main body 12 meet at
an interface. The barrel 14 has an outer diameter that is
substantially constant along its length. The interface between the
barrel 14 and the main body 12 includes an enlarged diameter
portion having an exterior surface diameter greater than the outer
diameter of the barrel 12. In this example, the enlarged diameter
portion may be formed as a flared frustoconically-shaped outer
surface 40. The enlarged diameter portion may function as a stop
that prevents the removable clamp 30 from being slid onto the main
body 12 and off of the barrel 14. In some examples, the flared
frustoconically-shaped outer surface 40 may aid in friction fitting
the removable clamp 30 when mounting, as the friction fit gets more
secure as the ring portion 32 is advanced further onto the flared
frustoconically-shaped outer surface 40. In yet other embodiments,
the enlarged diameter portion may not be flared and may not be
frustoconical in shape. In some embodiments, the enlarged diameter
portion may be implemented as a projection or other non-annular
element extending from the outer surface of the barrel 14 or the
main body 12 proximate the interface so as to stop axial movement
of the ring portion 32 in the direction of the main body 12. In
such embodiments, the enlarged diameter portion may be referred to
as a stop member.
[0034] In some examples, the barrel 14 may include an annular
groove into which is fit a retaining ring 42 in a location
proximate the interface. The retaining ring 42 may be slightly
larger in its outer diameter than the outer diameter of the barrel
12, such that when in place in the annular groove, the thickness of
the retaining ring 42 results in a slightly bulged annular part of
the barrel 14. The retaining ring 42 may be formed from a
heat-resistant material having a higher coefficient of friction
than the material used to form the barrel 12. In use, the retaining
ring 42 resists movement of the ring portion 32 once the removable
clamp 30 is in place on the appliance 10, and resists both axial
sliding of the removable clamp 30 and rotational movement of the
removable clamp 30.
[0035] Some implementations of the appliance 10 may feature the
retaining ring 42 or may feature the enlarged diameter portion, or
may feature both or neither. In some implementations, alternative
mechanisms may be used to retain the removable clamp 30 in position
once slid onto the barrel 14 towards the interface.
[0036] In one example, the appliance 10 may feature the annular
groove with no retaining ring 42. The ring portion 32 may include a
projection on its inner surface sized to snap-fit into the annular
groove. The projection may include an annular projection in the
form of a rib that extends for substantially the full inner
circumference of the inner surface. The projection may include a
single point protuberance, i.e. a boss, or multiple such
protuberances aligned along the inner circumferentially along the
inner surface. The rib or boss/bosses may snap-fit into the groove
when the ring portion 32 is slid into place proximate the
interface. The rib or boss/bosses in cooperation with the groove
may resist axial movement of the removable clamp 30.
[0037] Reference is now made to FIG. 3, which shows another example
embodiment of a hair care appliance 110. In this example, the
appliance 110 includes a barrel 114 that features a shallow
longitudinal channel 162. A removable clamp 130 has a ring portion
132 that features a projection 160 on its interior surface. The
projection 160 is sized to fit within the channel 162, such that
the removable clamp 130 may only be slid onto the barrel 114 when
oriented correctly to rotationally align the projection 160 with
the channel 162. This may prevent incorrect rotational movement of
the removable clamp 130 in some implementations. The end of the
channel 162 proximate the interface may include a ridge at the
channel bottom over which the projection 160 is to snap-fit, or a
deeper portion into which the projection 160 is to snap-fit so as
to resist further axial movement of the removable clamp 130 once
slid into place.
[0038] In some implementations, and as shown in this example, the
channel 162 may further include a partial annular channel 164 at
the end of the channel 162, into which the projection 160 is
rotated. The partial annular channel 164 prevents axial movement of
the removable clamp 130 once the projection 160 has been rotated
into the partial annular channel 164. The partial annular channel
164 may feature a ridge at the channel bottom over which the
projection 160 is to snap-fit, or a deeper portion into which the
projection 160 is to snap-fit so as to resist further rotational
movement of the removable clamp 130 once slid into place.
[0039] In this sense the barrel 114 and ring portion 132 are keyed
to ensure correct rotational alignment and to prevent rotation and
to prevent or resist axial movement once in place. It will be
appreciated that the groove/channel combination may be switched
such that the ring portion 132 features a groove and the barrel 114
features a projection in some implementations.
[0040] Reference is now made to FIG. 4, which shows, in block
diagram form, an example of a cordless hair care appliance 200. The
appliance 200 in this example includes a microcontroller 202 and a
rechargeable battery 204. The microcontroller 202 operates under
program control to coordinate and control operation of the other
components and circuitry in the appliance 200. The appliance 200
may include output devices, such as a display 210 and/or LED 212
indicators. The appliance 200 may further include input devices,
such as a power on/off button 214 or switch, and a temperature up
button 216 and a temperature down button 218. Signals from the
buttons 214, 216, 218 may be provided, subject to suitable
conditioning, to the microcontroller 202 for taking consequent
action. One or more temperature sensors 220 may also provide sensor
signals to the microcontroller 202 for regulating power supplied to
a heating element 228 dependent upon a current temperature setting.
In some implementations, the appliance 200 may further incorporate
additional components for safety purposes. For example, the
microcontroller 202 may be connected to an inertial sensor (not
shown), such as an accelerometer, to determine if the appliance 200
has been stationary for more than a threshold period of time while
being switched on and heated. If so, then the microcontroller 202
may be configured to turn the appliance 200 off. Similarly, the
appliance 200 may include a battery chamber temperature sensor (not
shown) to monitor the temperature proximate the battery(ies) and to
turn off the appliance 200 if the temperature exceeds a danger
level.
[0041] A DC voltage plug socket 206 is provided to accept a
connector from an AC adaptor to receive the DC power supply. In
some embodiments the AC adaptor supplies 9 VDC, however it will be
understood that the DC voltage supply may range from, for example,
5 VDC to 14 VDC. When the DC voltage plug socket 206 is connected
to a DC power supply, in this example, 9 VDC is provided to a
battery charge circuit 208 for recharging the battery 204.
[0042] The battery charge circuit 208 may be implemented using a
variety of possible configurations for recharging the battery 204
from an input DC supply current; however, in one example the
battery charge circuit 208 may step the 9 VDC down using, for
example, a DC voltage regulator. One example of such a regulator is
an LM7805 from Texas Instruments. The battery charge circuit 208
may further include a charge management control chip, such as the
MCP73831 chip from Microchip Technology Inc. for example. One or
more of the LEDs 212 may be incorporated into the battery charge
circuit 208 for signaling status of the charging operation, such as
whether the battery 204 is charging or is fully charged. The
microcontroller 202 may monitor the charges status and may cut off
the charge current when the battery 204 has been fully charged.
[0043] The heating element 228 requires certain power
characteristics in order to reach desired temperature levels. The
microcontroller 202 may adjust the maximum temperature setting
permissible dependent upon a number of factors, such as the current
battery charge level and/or whether a connector from an AC adaptor
is supplying current via the DC voltage plug socket 206. In some
implementations, if the appliance 200 is relying on battery power
alone, then the microcontroller 202 may impose a lower maximum
temperature setting. Moreover, the power supplied by the AC adaptor
is at 9 Volts DC, whereas the battery 204 offers 3.7 VDC in this
example. Accordingly, the appliance 200 includes a voltage booster
222 to provide an output of 9 VDC from the 3.7 VDC input by the
battery 204.
[0044] The heating element 228 is powered by a power controller 224
operating under control of the microcontroller 202. The power
controller 224, in this embodiment, may include a digital
potentiometer for dynamic adjustment of the power supplied to the
heating element 228. In one example the digital potentiometer is a
9-bit digital potentiometer featuring 100 k.OMEGA. end-to-end
resistance with an SPI serial interface. The wiper position varies
linearly and is controlled via the SPI interface, which operates
under control of the microcontroller 202 in response to adjustments
made via the temperature up/down buttons 216, 218. The digital
potentiometer controls the output current supplied to the heating
element 228 in both battery and battery-plus-plugged in modes.
[0045] One example implementation employs an 8-Bit microcontroller
as the microcontroller 202. One such example is the Atmel.TM.
ATmega32A microcontroller, although many others may be used in
other implementations. The microcontroller 202 may monitor and
control the other elements of the appliance 200, including shutting
down or powering off some elements in a power saving mode when
operating on battery power in order to better preserve battery
life.
[0046] Certain adaptations and modifications of the described
embodiments can be made. Therefore, the above discussed embodiments
are considered to be illustrative and not restrictive.
* * * * *