Note: Descriptions are shown in the official language in which they were submitted.
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ELECTRIC BLANKET CONTROL SYSTEM
FIELD OF THE INVENTION
The present invenr_ion relates to electric blanket control
devices, and more spec-~'ically to a digital, RF-signal,
electric blanket remote control system.
BACKGROUND INFORMATION
The fundamental a~~pects of electric blankets are well-
known in the art. An electric blanket generates heat as
electricity passes through the resistive wiring integral to
the blanket.. The amourat of heat generated depends on many
factors, but: two primary variables are the amount of
electricity allowed to glow through the blanket, affecting the
intensity oi: the heap, and its duration. Typically, a control
device is u~~ed to regulate the intensity and duration of heat
:LS generated. The duration of heat generation generally is
dependent on the time during which the blanket is turned on.
A simple ON/OFF power switch is a basic control device,
in that a presumably fixed amount of electricity passes
through the blanket while the control device is in the ON
:?0 state, generating a relatively constant intensity of heat.
Apart from residual heap dissipation, no heat is generated in
the OFF state. More so:chisticated control devices have used
timers to alternate between the ON and OFF states, effectively
regulating relative hear_ generation by controlling the
~!5 duration of heat generation, without altering the amount of
electricity passing through the blanket while in the ON state.
Another means or controlling the relative heat generation
while the blanket is turned on is to marginally adjust the
flow of electricity within the blanket through the use of a
30 variable flow control, analogous to a dimmer switch.
Increments o:E electric current adjustment may be coarse, such
as with control setting=~ of Low and High, or relatively fine,
such as with settings o.: 1 to 10, with 1 corresponding to the
lowest intensity of heap. and 10 corresponding to the highest
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intensity of heat. Relative heat generation in this context
is dependent: on electric energy consumption, independent of
the ambient temperatv~e near the blanket.
Electric blanket control devices may also regulate heat
generation by means ~:~ a thermostat in conjunction with a
variable cm-rent control device. Whereas a simple variable
current cont:rcl device operating by itself may maintain a
constant electric flow in the blanket, a thermostat may use a
variable current conr_rol to maintain a constant blanket
:~0 temperature by varying the electric flow in the blanket.
Ambient temperatures around the blanket will affect the
blanket temperature as heat is exchanged between them. As
ambient temF>eratures rise or fall, the thermostat may decrease
or increase, respectively, the flow of electricity to the
3.5 blanket to maintain a desired temperature.
Remote control systems are also well-known in the art.
Two popular methods of remote control involve infrared (IR)
signals and radio frequency (RF) signals. Infrared signals
are easily absorbed by objects in their path, so IR remote
a!0 control devices requ~:re a direct, 'unobstructed line-of-sight
between the IR remote control device and the base IR receiver.
Most television remote control systems, ~cr example, use IR
remote control device's .
Remote control ;systems that do not use IR signaling
25 typically may use other RF signals that are not easily
absorbed by objects i:: their path. RF remote control devices
generally do not require a direct, unobstructed line-of-sight
between the RF remotEe control and the base RF receiver.
Therefore, an RF remoc:e control may be operated to control a
?0 base unit from almost: any location within the effective range
of the RF transmission. The effective range of the RF
transmission will. depend largely on the strength and frequency
of the signal. Garage door openers, for example, typically
use RF remote control. systems .
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Digital displays are also well-known in the art. A
digital display typica:Lly may use either a liquid crystal
display (LCD) or a light:-emitting diode (LED) display. A
common digita:L sports watch, =or example, uses a digital
display havin<~ an LCD t:o ~3ispiay such data as the time, the
date, an alarm, and a stopwatch. Similarly, a common digital
microwave oven display, for example, uses an LED display, so
that it may be. read i:. little or no light, to display such
data as the time, the c:ooJcing intensity, and possibly the
temperature oi: the food.
Therefore:, it would be advantageous to design an electric
blanket control system that incorporates many of the benefits
of previous e3.ectric blanket control devices in a remote
control system using Rf sugnaling and having a user-friendly,
digital display.
SUMMARY OF THE INZ'EN:.'ION
The present invention relates to electric blanket control
devices, and more specifically to a digital, RF-signal,
electric blanket remote control system. An electric blanket
remote control. system according to the present invention may
include a remote contrcl device and a base unit. The remote
control device may include a case, a digital display, an RF
transceiver, electronic circuitry, a thermostat, a
microprocessor and a battery power supply connection. The
2!~ base unit may include a container, an RF transceiver, a
variable current control circuit, a safety detection circuit,
blanket connection circuitry, electronic circuitry, a
microprocessor, and power supply connection circuitry.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. lA-1B show block diagrams of an electric blanket
remote control device and an electric blanket base unit,
respectively, according to exemplary embodiments of the
present invention.
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FIG. 2 shows a perspective view of an electric blanket
remote contro:L device according to an exemplary embodiment of
the present invention.
FIG. 3 shows a plan view of the electric blanket remote
control device. of FIG. ...
FIG. 4 shows a perspective view of an electric blanket
base unit according to an exemplary embodiment of the present
invention.
Other features and advantages of the present invention
will be appare°_nt from tale following description of the
exemplary embodiments thereof, and from the claims.
DETAILED DESCRIPT7:ON
An electric blanket: :.emote contro_ system 1 according to
the present invention may znclude a remote control device 100
and a base un:Lt 200. Refc=rring to FIGS. lA-1B, FIG. lA shows
a block diagram of an electric blanket remote control device
100 according to an exemp:Lary embodiment of the present
invention. The remote control device 100 may include a case
110 (shown in FIGS. 2 and 3), a keypad 120, a digital display
130, an RF int:erface assembly 140, electronic circuitry 150, a
microcontrolle=r 160 anti a power suppler 170.
As shown in FIG. :.A, the microcontroller 160 may be
coupled to each of the k:e~rpad 120, the digital display 130,
the RF interface assembly 140, and the power supply 170. The
microcontrolle:r 160 may include, for example, a central
processing un::t (CPU) 1.61,, read-only memory (ROM) 162, random-
access memory (RAM) 16., an input port 164, an output port
165, and a display driver 166. Furthermore, the input port
164 interfaces the kevz~ad 120 with the CPU 161, the output
port interfaces the RF i.nt:er=ace assembly 140 with the CPU
161, and the display driver 166 interfaces the digital display
130 with the (:PU 161.
The keypad 120 may include an LED backlight 122.
Likewise, the digital cii.splay 130 may include a LED backlight
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132. The RF' interface assembly 140 may include an RF
transmitter 141 connected to an antenna 142. The power supply
170 may inc7.ude, for example, a battery bay to hold 2 ~~AAA"
sized batten-ies. Alternatively, the power supply 170 may
5 include a rechargeable power cell that is recharged by a
separate rec:harger assembly, which could be attached by a
detachable recharges cord.
Although not shown in FIG. lA, the remote control 100
also may include a thermostat 180 having a thermometer 181
:l0 with which remote con~rol 100 measures the ambient
temperature. The remote control 100 therefore may display the
ambient temperature o;z the display 130. Furthermore, the
system 1 may use the ambient temperature instead of the
blanket temperature as a variable in adjusting the heat
:L5 intensity level applied by the base unit 200. Thus, the
thermostat 180 may compensate the blanket heat level for the
ambient room temperar_ure. First, the thermometer 181 may
measure the ambient temperature, and second, the thermostat
180 may apply temperature compensation to the heat level
:?0 commands sent to the base unit 200 to maintain constant
blanket temperature as the ambient temperature varies. An
algorithm 182 stored in the remote control 100 calculates how
much to adjust the heat level relative to the ambient
temperature to maintain a desired blanket temperature.
:?5 Likewise, the thermostat 180, thermometer 181, and the
algorithm 182 may be .Located on the base unit 200 instead of
on the remote contro:~ device 100, but this would require that
the remote control device 100 be able to receive data
transmitted by the base unit 200 in order for the display 130
:SO of the remote contro__ device 100 to show the ambient
temperature measured at the base unit 200. Such a
configuration would require the use of RF transceivers in both
the remote control device 100 and base unit 200, as discussed
in detail below. If RF transceivers are used, the thermometer
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181 may be separated from the thermostat 180 and the algorithm
182, allowing for the ambient temperature data to be compiled
at one place and transmitted to another place.
By comparison, FIc.;. 1B shows a block diagram of an
electric blanket base unit 200 according to an exemplary
embodiment of the present invention. The base unit 200 may
include an RF interf:ace assembly 210, a microcontroller 220,
electronic circuitry 2:30, power supply connection circuitry
240, blanket connection circuitry 250, a safety detection
circuit 260, a variable current control circuit 270 and a
container 280 (shown in FIG. 4).
As shown in FICJ. :LB, the microcontroller 220 may be
coupled via the electronic circuitry 230 to each of the RF
interface assembly 210,, the power supply connection circuitry
240, the blanket connection circuitry 250, the safety
detection circuit 260, and the variable current control
circuit 270. The mi.crocontroller 220 may include, for
example, a central processing unit (CPU) 221, read-only memory
(ROM) 222, random-access memory (RAM) 223, input ports 224,
and an output port 225. Furthermore, the input ports 224
interface the RF interface assembly 210 and the safety
detection circuit 260 caith the CPU 221, and the output port
225 interfaces the war_Lable control circuit 270 with the CPU
221.
The RF interface assembly 210 may include an RF receiver
211 connected to an antenna 212. The power supply connection
circuitry 240 may include an alternating current-to-direct
current (AC/DC) converter 241 and a power cord 242 (shown in
FIG. 4) adapted to pi.u<3 into a power outlet. The AC/DC
converter 241 supplies a direct current to the microcontroller
220. The power supply connection circuitry 240 may provide
120V AC to the variable control circuit 270. The blanket
connection circuitry 250 may include a blanket cord 251 (shown
in FIG. 4) coupling the base unit 200 to the blanket. For
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easier disassembly and storage, power cord 242 and blanket
cord 251 ma~r attach and detach from the base unit 200, and
blanket cord 251 may attach and detach from the blanket. The
variable control circuit 270 interfaces the power supply with
the blanket connection circuitry X50 and modulates the duty
cycle of the' power supplied to the blanket. The safety
detection circuit 260 may monitor blanket sensors (not shown)
or it may simply monitor the electrical feed-back from the
power supplied by the variable control circuit 270. If for
20 example the safety detection circuit 260 detects a drop in
resistance that may indicate a local short circuit, the safety
detection c:.rcuit 260 may instruct the microcontroller 220 to
deactivate t:he blanket.
In the event that the remote control system 1 intends to
have the remote control device 100 receive data transmitted
from the base unit 200 as well as have the base unit 200
receive data transmitted from the remote control device 100,
RF transmitt:er 141 of F'IG. lA and RF receiver 211 of FIG. 1B
may be replaced with Rf transceivers 143, 213 (not shown)
coupled to both the input and output ports, respectively 164,
165 and 224, 225. T:he use of RF transceivers 143, 213 would
permit the base uni~ 200 to communicate the status of the
blanket to t:he remote control device 100.
For example, base unit 200 could inform the remote
;Z5 control device 100 t:~at the blanket is not plugged in to the
base unit 200, preventing the execution of any instructions
received from the remote control device 100. Similarly, if a
battery were coupled to the base unit 200, the base unit 200
would have z>ower to inform the remote control 100 that the
:30 power supply connection 240 is not plugged into a power
outlet. They base unit 200 could also relay intermediate
status information tc~ the remote control device 100. For
example, the blanket may include a blanket thermometer coupled
to the safety detection circuit 260, allowing the base unit
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200 to transmit the current blanket temperature compared to
the programmed blanJzet temperature. Similarly, the safety
detection circuit 260 may measure the electrical resistance of
the blanket, and the. microcontrolier 220 may calculate the
current blanket temperature using a temperature algorithm
dependent on the measured electrical resistance of the blanket
relative to the electrical power supplied to the blanket.
FIGS. 2 and 3 respectively show a perspective view and a
plan view of an electric blanket remote control device 100
according to an exemplary embodiment of the present invention.
The case 110 may house the keypad 120, the digital display
130, the RF interfac:e assembly 140 (shown in FIG. lA), the
electronic circuitr~r 150 (shown in FIG. lA), the
microcontroller 160 (shown in FIG. lA) and the power supply
I5 170 (shown in FIG. 1.A). The keypad 120 may include buttons
121 and a keypad LED backlight 122 (shown in FIG. lA) to
illuminate the buttons 121. The display 130 may include a
multifuncti«nal, digital LCD 131 and a display LED backlight
132 (shown :in FIG. 1A) .
FIG. 4 shows a perspective view of an electric blanket
base unit 200 according to an exemplary embodiment of the
present invention. T'he container 280 may house the RF
interface assembly 210 (shown in FIG. 1B), the microcontroller
220 (shown :in FIG. 1B), electronic circuitry 230 (shown in
FIG. 1B), the power supply connection circuitry 240, the
blanket connection circuitry 250, the safety detection circuit
260 (shown _~n FIG. 1B), and the variable current control
circuit 270 (shown in F'IG. 1B).
The container 280 also may include one or more LED
indicators a?81 and a sound generator 282, both of which are
coupled to microcontrol.ler 220. In the event that the base
unit 200 separately controls two blankets or two halves of one
blanket, two LED indicators 281 may indicate the independent
activation of each blanket or blanket half. The LED indicator
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281 may luminesce when the associated electric blanket is
activated. The sound generator 282 may beep or chirp to
acknowledge reception of instructions from the remote control
100 or to wound an alarm signaled by the safety detection
circuit 260. The sound generator 282 may comprise a
loudspeaker, a piezoelectric element, or the like.
Given the intelligence of microcontrollers 160 and 220,
the remote control sy~~tem 1 rnay perform a wide variety of
functions. Generally, each function will have an associated
field on the digital display 130. The LCD 131 may have fixed
fields 133 and variable fields 134 that are activated when the
associated function is being programmed and displayed. For
example, a preheat function may be disgiayed by a fixed field
133 to indicate tha~~ the preheat function is active or being
programmed. Conversely, a clock function requires a variable
field 134 t.o display the passage of time. As shown in FIGS. 2
and 3, an exemplary LCD 131 may display information regarding
the status of up to two electric blankets (e.g., left and
right), including among others the power status (On/Off/Auto),
heating level, the time, heating times, and the heating
duration.
As discussed, an electric blanket control device may
employ several diffe~re:nt methods to regulate the heating of
the blanket. In con~iu;nction with the microcontroller 160 of
the remote control 1.UU, the microcontroller 220 of the base
unit 200 regulates t:he heating of a blanket coupled to the
base unit 200. A user will input a desired heating regime
into the remote cont.ro:1 10U, and the remote control 100
programs the base ur.,~.t 200 accordingly. The base unit 200 may
regulate the heatino~ of a blanket by varying start and stop
times, the duration of the heating, the intensity level of the
heat, and tine desired temperature of the blanket.
By combining two or more of these variables, the base
unit 200, fc~r example, may preheat a blanket quickly to a
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desired temperature or level by applying the maximum heat for
a short period until the desired status is reached and then
reducing the heat t:o maintain the desired status. Similarly,
the base unit 200 rnay be programmed to intermittently heat the
5 blanket over a longer period, such as while a user sleeps.
Intermittent ramping of heat may generate heat more
efficiently with less excess, avoid overheating the blanket,
and prolong the life of the blanket.
Note that while a remote control system 1 according to
10 the present invention generally will be sold with one or two
removably attached electric blankets, it may be feasible to
use the system 1 with a different blanket, so long as the
blanket is compatible with the power source connection 250 and
the electrical output of the base unit 200. As is often the
case, a power cord plugged into an electric blanket may be
detachable from the blanket to facilitate laundering of the
blanket. Accordingly, assuming a compatible match, an
existing blanket control device may be unplugged from an
existing blanket arad replaced with the base unit 200 for use
of the system 1 with t:he existing blanket.
A number of embodiments of the present invention have
been described above. Nevertheless, it will be understood
that various modifications may be made without departing from
the spirit and scope of the invention. Accordingly, other
embodiments are within the scope of the following claims. It
is intended that all matter contained in the above description
or shown i:n the accompanying drawings shall be interpreted as
illustrative and not in a limiting sense. It is also
understood that the following claims are intended to cover all
of the generic and specific features of the invention herein
described and all statements regarding the scope of the
invention.
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