Note: Descriptions are shown in the official language in which they were submitted.
21~053~
ELECTRONIC DEVICE HAVING INTERNAL CHARGE
REGULATOR FOR CONTROLLING APPLICATION
OF A CHARGING CURRENT THERETO AND
ASSOCIATED METHOD THEREFOR
Background of the Invention
The present invention relates generally to electronic devices
10 which may be powered by rechargeable power supplies and, more
particularly, to an electronic device, and an associated method,
connectable to an external power source capable of providing
operative power to power an electronic device and also to recharge a
rechargeable power supply of the electronic device.
Many electronic devices are constructed of designs which
permit powering thereof by a battery comprised of one or more battery
cells. In some instances, use of a battery power supply to power the
electronic device is necessitated when the electronic device is not, or
cannot be, positioned proximate to a permanent, or other fixed, power
~0 supply. In other instances, a battery power supply is utilized to
power the electronic device to increase the portability of the device as
no power cable is required to interconnect the electronic device to the
permanent, or other fixed, power supply. Typically, the one or more
battery cells comprising the battery power supply utilized to power
25 the electronic device are carried directly with, or housed within, the
electronic device.
However, because a battery power supply is capable of storing
only a finite amount of energy, powering of the electronic device with
the battery power supply is limited by the energy storage capacity of
30 the battery power supply. Powering of the electronic device by the
battery power supply causes discharge of the stored energy of the
battery power supply. Once the stored energy of the battery power
supply is discharged beyond a certain level, replacement of the
battery power supply is necessitated to permit continued operation of
35 the electronic device. Increasing the energy storage capacity of a
214V5~5
-
- 2 -
battery power supply, such as by increasing the number of battery
cells comprising such power supply, increases the size (and weight)
of the power supply. Such manner of increasing the energy storage
capacity of a battery power supply reduces the portability of the
5 electronic device when the battery power supply is carried with the
electronic device. Accordingly, when designing a battery power
supply, a compromise is made between increased energy storage
capacity and reduced portability of the electronic device which carries
such a battery power supply.
A portable or transportable radiotelephone is one such
electronic device which is typically powered by a battery power
supply. The battery power supply is typically carried directly with the
radiotelephone and is of a size and weight which does not unduly
constrain the portability of the radiotelephone. A radiotelephone
15 includes radio transceiver circuitry including transmitter circuitry
and receiver circuitry which is operative to transmit and to receive,
respectively, modulated signals. In typical operation of a
radiotelephone, receiver circuitry portions thereof are powered
continuously while awaiting reception of signals indicative of an
20 incoming call to the radiotelephone. Thereafter, the transmitter
circuitry portions of the radiotelephone are also powered to permit
transmission of modulated signals therefrom. .
Radiotelephones operative in many cellular communication
systems are constructed to transmit modulated signals therefrom
25 and also simultaneously to receive modulated signals transmitted
thereto (the modulated signals transmitted by and to the
radiotelephone are transmitted upon separate frequency channels).
Radiotelephones operative in other cellular communication systems
are constructed to transmit and to receive modulated signals during
30 nonsimultaneous time periods and, during two-way communication
with the radiotelephone, the receiver and transmitter circuitry
portions are powered during nonsimultaneous time periods.
Times during which the receiver circuitry portions of the
radiotelephone are powered while awaiting transmission thereto of
35 signals indicative of an incoming call shall hereinafter be referred to
214~35
- 3 -
as times in which the radiotelephone is in the "standby" mode. (It
should, of course, be noted that a user of a radiotelephone also
oftentimes provides operative power to the radiotelephone only when
the user desires to initiate and thereafter effectuate a telephone call;
5 during other times no operative power is provided to the
radiotelephone, and the radiotelephone is not powered to receive
signals transmitted thereto. That is to say, the user of the
radiotelephone may choose not operate the radiotelephone in the
"standby" mode to receive an incoming call transmitted to the
10 radiotelephone, but rather power the radiotelephone only during
times in which the user initiates a telephone call.)
Generally, the amounts of energy required to operate the
transmitter circuitry portions of the radiotelephone are greater than
the amounts of energy required to operate the receiver circuitry
15 portions thereof. And, because practical devices are of less than ideal
efficiencies, a certain portion of the energy applied to the
radiotelephone is converted into heat energy which results in heat
build-up of the radiotelephone. As more energy is required to operate
the transmitter circuitry portions of the radiotelephone, there is a
~0 correspondingly greater amount of heat generation during operation
of the transmitter circuitry portions of the radiotelephone than when
only the receiver circuitry portions are operable,
Rechargeable battery power supplies have been developed and
are commercially available. Some of such commercially-available,
25 rechargeable battery power supplies are of constructions designed for
use to power radiotelephones. The use of rechargeable battery power
supplies is advantageous as the rechargeable batteries may be
recharged by applying a charging current generated by a power
supply thereto. Once recharged, the rechargeable battery power
30 supply may be reused. Some constructions of rechargeable battery
power supplies may be recharged, and reused, up to, and even in
excess of, five hundred times.
As mentioned previously, a battery power supply is typically
comprised of one or more battery cells. The cells are connected in a
35 series (or other) connection, and are typically housed within a
21~U5~5
common housing. The housing, together with the battery cells,
comprise the battery power supply which is also oftentimes referred
to as a battery pack. For purposes of simplicity, such constructions
are also generically referred to by the general term "battery". The
5 present disclosure shall, at times, utilize such simplified
term inology.
The battery cells of a rechargeable battery power supply are
formed of various different materials of construction. For instance, a
rechargeable battery cell may be comprised of a lithium (Li) material,
10 a nickel-cadmium (Ni-Cd) material, or a nickel metal hydride
(NiMHO2) material. Battery cells constructed of these different
materials exhibit different characteristics during charging thereof.
Battery charging apparatus is also commercially available to
permit recharging of rechargeable batteries. A battery charger
15 comprising such battery charging apparatus is typically comprised
of a power source for supplying operative power to recharge the
rechargeable battery power supply when suitably connected to the
charging apparatus to receive the operative power.
The energy of the operative power applied to the rechargeable
20 battery power supply is converted into chemical energy which is
stored by the rechargeable battery cells of the battery power supply.
Application of the operative power to the battery.cells over an elapsed
period of time permits the rechargeable battery cells to become fully
recharged. Again, however, because practical devices are of less
25 than ideal efficiencies, a certain portion of the energy applied to the
battery cells are converted into heat energy which causes heat build-
up of the battery cells.
Some battery charging apparatus are of construction-types
which permit the electronic device and also the battery power supply
30 both to receive operative power. Such battery charging apparatus
provides operative power not only to recharge the rechargeable
battery cells of the battery power supply but further provides operative
power to permit operation of the electronic device.
For instance, battery charging apparatus of construction-types
35 permitting a radiotelephone together with a rechargeable battery
21~0S35
pack to receive operative power to recharge the battery cells of the
battery pack and also to permit operation of the circuitry of the
radiotelephone is available. As mentioned previously, however, in
practical devices, heat is generated as a byproduct of operation of the
5 circuitry of the radiotelephone. And, heat is also generated as a
byproduct of the process of recharging the battery cells of the battery
power supply.
As also noted previously, greater amounts of energy are
required to operate the transmitter circuitry portions of the circuitry
10 of the radiotelephone. Because a portion of the operative power
applied to the radiotelephone is converted into heat energy, and heat
energy is also generated during recharging of the rechargeable
battery cells of the battery pack, an excessive amount of heat build-up
of the radiotelephone may occur when operative power is provided
15 both to recharge the battery cells of the battery pack and also to
operate portions of the circuitry of the electronic device, here the
radiotelephone and particularly during times in which the
transmitter circuitry portions of the radiotelephone are operable.
What is needed, therefore, is means by which operative power
20 may be provided to an electronic device including a rechargeable
power supply but which prevents excessive heat build-up as a result
of application of the operative power to the electronic device.
Summary of the Invention
The present invention, accordingly, provides a device, and
associated method, which overcomes the problems associated with
the existing art.
The present invention further advantageously provides an
30 electronic device including a rechargeable power supply wherein the
electronic device is connectable to a variable-level power source
which provides operative power to recharge the rechargeable power
supply and also to provide operative power to operate electronic
circuitry of the electronic device.
21~3~
The present invention includes further advantages and
features, the details of which will become more apparent upon
reading the following detailed description of the preferred
embodiments.
In accordance with the present invention, therefore, a
electronic device, and associated method, releasably connectable to a
variable-level power source is disclosed. The electronic device is
operable to receive operative power of either of at least two power
levels generated by the variable-level power source. The electronic
device comprises connecting elements which permit releasable
connection with the variable-level power source. The connecting
elements include at least a first connecting element and a second
connecting element wherein the first connecting element permits
connection of the variable-level power source to receive operative
power thereat. A rechargeable power supply is coupled to receive a
charging signal responsive to times in which the variable-level power
source is connected to the first connecting element of the connecting
elements and generates the operative power of a first power level of
the either of the at least two power levels. Electronic circuitry is
coupled to receive alternately either the operative power generated by
the variable-level power source provided at the first connecting
element or power generated by energy stored by the rechargeable
power supply. Control circuitry is coupled to the electronic circuitry
and is operative to generate a power-source control signal for
application to the second connecting element of the connecting
elements wherein the power-source control signal is of either of at
least a first signal level to cause the operative power of the variable-
level power source to be of a first of the at least two power levels or of a
second signal level to cause the operative power of the variable level
power source to be of a second of the at least two power levels.
~u53~
Brief Description of the Drawings
The present invention will be better understood when read in
light of the accompanying drawings in which:
FIG. 1 is a block diagram of an electrical device of a preferred
embodiment of the present invention connected to a variable-level
power source;
FIG. 2 is a block diagram, similar to that of FIG. 1, but of a
preferred embodiment of the present invention connected to a
variable-level power source;
FIG. 3 is a partial block, partial circuit schematic diagram of a
charge regulator which forms a portion of the electronic device of
FIG. 1 and the radio transceiver of FIG. 2;
FIG. 4 is a schematic representation of a cellular
radiotelephone, similar to the radio transceiver shown in block form
in FIG. 3, of a preferred embodiment of the present invention;
FIG. 5 is a flow diagram listing the method steps of an
algorithm executable by control circuitry which forms a portion of the
radio transceiver of FIG. 2 and the electronic device of FIG. 1; and
FIG. 6 is a flow diagram listing the method steps of the method
of a preferred embodiment of the present invention.
Description of the Preferred Embodiments
As mentioned hereinabove, a portable electronic device is
oftentimes powered by a rechargeable power supply. When the
rechargeable power supply is depleted of stored energy, battery
charging apparatus is utilized to recharge rechargeable battery cells
of the rechargeable power supply.
Several constructions of battery charging apparatus are
available which permit the portable electronic device to be positioned
together with the rechargeable power source carried therewith such
that operative power is provided both to the rechargeable battery cells
of the rechargeable power supply and also to the circuitry of the
electronic device.
2140~3~
However, because power transfer between the battery charging
apparatus and the electronic device is not wholly efficient, a certain
portion of the energy of the operative power generated by the battery
charging apparatus is converted into heat energy which, during
5 dissipation thereof, elevates the temperature of the electronic device.
When operative power generated by the battery charging apparatus is
utilized both to recharge the battery cells of the rechargeable power
supply and also to operate the circuitry of the electronic device, heat
energy is generated during operation of both processes.
In the particular instance in which the electronic device
comprises a radiotelephone operative in a cellular communication
system, battery charging apparatus may be constructed to provide
operative power to recharge the rechargeable battery cells of the
rechargeable power supply carried with the radiotelephone while
15 also providing operative power to permit operation of transmitter and
receiver circuitry portions of the radiotelephone.
As mentioned hereinabove, greater amounts of power are
required to operate transmitter circuitry portions of the
radiotelephone than to operate receiver c.ircuitry portions thereof.
~0 Hence, when a radiotelephone (or other radio transceiver) having a
rechargeable power supply is positioned to recharge the battery cells
of the rechargeable power supply and the radiotelephone is
simultaneously operated, greater amounts of power are required
during times in which the radiotelephone is operative to transmit
25 modulated signals than during times in which the radiotelephone is
operative only to receive modulated signals. (As also noted
hereinabove, a radiotelephone is oftentimes operated in the "standby"
mode in which only the receiver circuitry portions of the
radiotelephone are operable while awaiting reception of modulated
30 signals indicative of an incoming telephone call. Only during times
in which two-way communication is to be, or is, effectuated between
the radiotelephone and a remote location must the transmitter
circuitry portion of the radiotelephone be operable.) Accordingly,
because greater amounts of power are required during times in
35 which the transmitter circuitry portions of the radiotelephone are
214053~
operated than during times in which only the receiver circuitry
portions of the radiotelephone are operated, greater amounts of heat
energy are produced during times in which the transmitter circuitry
portions of the radiotelephone are operated.
Battery charging apparatus operative to permit both
recharging of the battery cells of the rechargeable power supply and
also to power the circuitry of the electronic device must generate
power at power levels permitting both such recharging and such
operation. Battery charging apparatus operative to generate a
charging signal of only a single power level must generate the signal
to be of a power level permitting simultaneous recharging of the
battery cells of the rechargeable battery power supply and also to
operate the electronic circuitry of the electronic device. When the
electronic device is not being operated, such battery charging
apparatus generates a charging signal of the same power level as the
power level of the charging signal generated when the circuitry of the
electronic device is being operated. The power which would
otherwise be utilized to power the circuitry of the electronic device is
not utilized for any useful purpose and is, instead, converted into
~0 heat energy.
In the particular instance in which the electronic device
comprises a radiotelephone, battery charging apparatus operative to
permit both recharging of the battery cells of a rechargeable power
supply carried with the radiotelephone and also to power the
transceiver circuitry thereof may be constructed. But when such
battery charging apparatus is operative to generate a charging signal
of only a single power level, the power level must be great enough to
permit, simultaneously, recharging of the battery cells of the
rechargeable power supply and also operation of both the receiver
circuitry portion and the transmitter circuitry portion of the
radiotelephone.
While the receiver circuitry portion of the radiotelephone is
oftentimes powered to be in the "standby" mode of operation, the
transmitter circuitry portion is only powered during times in which
two-way communication is to be effectuated with a remote site. As
0~35
- 10-
the transmitter circuitry portion of the radiotelephone is operative
only during times in which two-way communication is, or is to be,
effectuated, in many instances, when the radiotelephone together
with the rechargeable power supply is positioned to receive the
5 charging signal generated by the battery charging apparatus
operative to generate the charging signal of only a single power level,
the radiotelephone is even more susceptible to overheating as
excessive amounts of power are converted into heat energy.
Battery charging apparatus operative to generate a charging
10 signal of a power level which is variable responsive to power
requirements of the electronic device which carries the rechargeable
battery source would be advantageous.
In the particular instance of the radio transceiver such as the
radiotelephone, battery charging apparatus operative to prevent
15 overheating of the transceiver when the transmitter circuitry portion
thereof is operative would be particularly advantageous.
Turning first then to the block diagram of FIG. 1, an electronic
device, referred to generally by reference numeral 10, of a preferred
embodiment of the present invention is positioned in releasable
20 connection with variable-level power source 16. Variable-level power
source 16 is connected to electronic device 10 by way of lines 22 and 28,
respectively, at connecting elements 34 and 40, here shown to be plug
connectors represented by plug terminals enclosed by rectangles,
indicated in dash. Variable-level power supply 16 may, in turn, be
25 connected to a conventional household power supply (by way of
connection with plug connector 36) or other suitable power supply.
Variable-level power source 16 is operative to generate a
charging signal on line 22 which is of either of at least two separate
power levels. (In a further embodiment of the present invention,
30 power source 16 is operable to generate a charging signal on line 22
which is of any of many levels between a maximum and minimum
charging level.)
Line 46 of electronic device 10 is coupled to receive the charging
signal generated by variable-level power source 16 on line 22. Line 46,
35 in turn, is coupled to electronic circuitry 52 of electronic device 10 to
~1~0~3~
- 11-
provide operative power thereto when power source 16 is connected to
connecting element 34 by way of line 22 to provide operative power
thereto.
Line 46 is further coupled to charge regulator 58 which
regulates the value of the charging signal applied thereto on line 46
and generates a regulated, charging signal on line 64 which is
coupled to rechargeable battery power supply 70. Power supply 70 is
comprised of one or more rechargeable battery cells. Through such
connection, the charging signal generated by power source 16 on line
22 is applied to rechargeable battery power supply 70 to recharge the
rechargeable battery cells thereof.
The battery cells of rechargeable battery power supply 70
convert the energy of the charging signal generated by power source
16 and regulated by charge regulator 58 into chemical energy which
is stored in the battery cells of the rechargeable battery power supply.
Battery power supply 70 is coupled to electronic circuitry 52 by
way of line 76. When power source 16 is not connected to electronic
device 10 to apply a charging signal thereto, the stored energy of
battery power supply 70 is utilized to power circuitry 52 to permit
operation of electronic device 10 thereby. Powering of circuitry 52
with the stored energy of battery power supply 70, however, and as
noted hereinabove, discharges the stored energy of the battery power
supply. Once the stored energy of battery power supply 70 is depleted
beneath a certain level, the battery cells of the battery power supply
must be recharged by applying a charging current to the battery
power supply to recharge the battery cells thereof.
Control circuitry 82 further forms a portion of electronic device
10. Control circuitry 82 is coupled to electronic circuitry 52 by way of
line 88 and to charge regulator 58 by way of line 94. Control circuitry
82 is further coupled to connecting element 40 by way of line 100,
thereby to permit connection of control circuitry 82 to line 28 which,
in turn, is connected to variable-level power source 16. And, control
circuitry 82 is also preferably coupled to rechargeable battery power
supply 70 by way of line 106.
~0535
- 12-
Electronic device 10 further includes input element 112 which
is coupled to electronic circuitry 52 by way of line 118. Similarly,
display element 124, comprised of, for example, light emitting diodes,
is also coupled to electronic circuitry 52, here by way of line 128. A
5 user of electronic device 10 operates device 10 by appropriate
actuation of input element 112 (such as, for example, actuating an
off/on actuation switches which may comprise portions of input
element 112). Portions of electronic circuitry 52 operative responsive
to such inputs connect circuit elements thereof to receive operative
10 power on either line 46 which is generated by power source 16 when
connected to device 10 by way of connecting element 34 or, otherwise,
to battery power supply 70. When electronic circuitry 52 is operative,
a signal indicative of such operation is supplied to control circuitry 82
by way of line 88.
Responsive to the signal supplied thereto on line 88, control
circuitry 82 generates a signal of a first signal value on line 100
which, in turn, is supplied to line 28 by way of connecting element 40
to be applied to variable-level power source 16 when connected to
connecting element 40 by way of line 28. When, conversely, electronic
circuitry 52 is not to be operated, a signal of a second signal value (or
no signal) is generated on line 88 and applied to control circuitry 82.
In such instances, control circuitry 82 generates-a signal of a second
signal level value (or no signal) on line 100 which similarly may be
applied to variable-level power source 16.
When variable-level power source 16 is connected to connecting
element 40, power source 16 thereby receives a signal on line 28
indicating whether electronic circuitry 52 is being operated.
When electronic circuitry 52 is being operated and power
source 16 is connected to electronic device 10, the charging signal
generated by power source 16 on line 22 must be of a power level great
enough to power circuitry 52. When, conversely, electronic circuitry
52 is not to be operable, power source 16 need not generate a charging
signal of a power level to cause operation of circuitry 52.
As the charging signal generated by power source 22 is further
utilized to recharge the battery cells of battery power supply 70, the
- ~14053~
- 13-
charging signal generated by power source 16 must be of a power
level to recharge adequately the battery cells of the battery power
supply. Charge regulator 58, operative to regulate the level of the
charging signal generated by power source 16 on line 22 generates a
5 regulated charging signal on line 64 which is applied to the battery
cells of battery power supply 70.
Control circuitry 82 is further operative to generate a control
signal on line 94 to control the level of the regulated charging signal
applied to the battery cells of the battery power supply. The value of
10 the control signal generated on line 94 by control circuitry 82 may, at
least in part, be determined by measured voltage levels taken across
battery power supply 70 and supplied to control circuitry 82 by way of
line 106. (Voltage levels taken across power supply 70 may be
measured in any conventional manner.)
In a first preferred embodiment of the present invention, when
power source 16 is connected to electronic device 10 by way of
connecting elements 34 and 40, power source 16 generates a signal of
a low power level on line 22 during times in which electronic
circuitry 52 is operative. And, power source 16 generates a signal on
line 22 of a high power level when electronic circuitry 52 is not, or is
not to be, operative. When electronic circuitry 52 is not, or is not to be,
operative, the signal generated on line 22 by power source 16 is of a
sufficiently high power level to recharge the battery cells of battery
power supply 70.
In another preferred embodiment, power source 16 is operative
in a similar manner, but the signal generated on line 22 is further
dependent upon the amount of charge stored in battery power supply
70. (And the amount of charge stored in power supply 70 is
proportional to the voltage levels taken thereacross.) That is to say,
when the value of the signal generated by control circuitry 82 on line
100 is of a value dependent, at least in part, upon the value of the
signal applied to control circuitry 82 on line 106, variable-level power
source 16 generates a signal on line 22 at a level between the
aforementioned two power levels wherein the particular power level
2~4~535
- 14-
of the signal is dependent upon the amount of charge already stored
in the battery cells of battery power supply 70.
In either embodiment, however, the power level of the signal
generated by variable-level power source 16 on line 22 is selected to be
of a value to minimize excessive heat generation during operation of
electronic device or recharging of the battery cells of battery power
supply 70.
Turning next to the block diagram of FIG. 2, a radio
transceiver, here a radiotelephone, referred to generally by reference
numeral 210, of a preferred embodiment of the present invention is
shown. Radiotelephone 210 corresponds to electronic device 10 of
FIG. 1. Variable-level power source 216 is releasably connectable to
radiotelephone 210 by way of lines 222 and 228 which are connected to
connecting elements 234 and 240, here shown to be plug connectors,
represented by plug terminals positioned within the rectangles
shown in dash. Variable-level power source 216 may, in turn, be
connected to a conventional, household power supply (by way of
connection with plug connector 236) or the power supply of a motor
vehicle. Power source 216 is operative to generate a charging signal
on line 222 of a selected power level.
Line 246 of radiotelephone 210 interconnects connecting
element 234 and transceiver circuitry of radiotelephone 210, here
shown to be comprised of receiver circuitry portion 250 and
transmitter circuitry portion 252. When power source 216 is
connected to connecting element 234 of radiotelephone 210, the signal
generated by power source 216 is permitted to be applied to receiver
and transmitter circuitry portions 250 and 252 to provide circuitry
portions 250 and 252 with operative power to operate the respective
circuitry portions.
Charge regulator 258 also forms a portion of radiotelephone 210
and is coupled to line 246 to receive the signal generated by power
source 216 when power source 216 is connected to connecting element
234 by way of line 222. Charge regulator 258 is operative to regulate
the value of the signal applied thereto on line 246 and to generate a
regulated, charging signal on line 264 which is applied to
~0~3~
- 15-
rechargeable battery power supply 270 to permit recharging of the
battery cells thereof.
Rechargeable battery power supply is coupled to receiver and
transmitter circuitry portions 250 and 252 by way of line 276. When
variable-level power source 216 is not connected to radiotelephone 210,
energy stored within the battery cells of rechargeable battery power
supply 270 is utilized to provide the operative power to operate
receiver and transmitter circuitry portions 250 and 252.
Control circuitry 282 is coupled to the receiver and transmitter
circuitry portions 250 and 252 by way of line 288, to charge regulator
258 by way of line 294, to connecting element 240 by way of line 300,
and to rechargeable battery power supply 270 by way of line 306.
Signals provided to control circuitry 282 on line 288 are
indicative of times in which circuitry portions 250 and 252 are
operative. (As mentioned previously, during operation of
radiotelephone 210, receiver circuitry portion 250 is oftentimes
powered in the "standby" mode while the transmitter circuitry
portion of the radiotelephone is typically operative only during times
in which two-way communication is to be effectuated by the
radiotelephone.)
When only receiver circuitry portion 250 or neither receiver nor
transmitter circuitry portions 250 or 252 are operable, control
circuitry 282 generates a signal on line 300 for application to variable-
level power source 216 by way of connecting element 240 and line 228
of a first signal level. Conversely, when signals applied to control
circuitry 282 on line 288 indicate that transmitter circuitry portion
252 is, or is to be, operable, control circuitry 282 generates the signal
on line 300 to be of a second signal level. Responsive thereto, power
source 216 generates a signal on line 222 of a power level dependent
upon the signal level of the signal generated on line 300 by control
circuitry 282.
In a preferred embodiment of operation of radiotelephone 210,
when transmitter circuitry portion 252 is not, or is not to be, operable,
the signal of the first signal level generated on line 300 by control
circuitry 282 causes power source 216 to generate a signal on line 222
~4~35
- 16-
of a power level to permit recharging of the battery cells of battery
power supply 270.
When transmitter circuitry portion 252 is operative, control
circuitry 282 generates the signal on line 300 of the second signal
level value to cause power source 216 to generate a signal on line 222
which is of a second power level which permits operation of the
transmitter circuitry portion 252 (and also receiver circuitry portion
250) but not to recharge the battery cells of rechargeable battery power
supply 270. In such manner, recharging of the battery cells of
rechargeable battery power supply 270 occurs only when transmitter
circuitry portion 252 is not operative. Thereby, overheating of
radiotelephone 210 responsive to simultaneous recharging and
transmission is avoided.
The control signal generated by control circuitry 282 on line 294
is operative to control operation of charge regulator 258. When the
signal generated by power source 216 is to be utilized to apply a
charging current to recharge the battery cells of battery power supply
270, the charge control signal generated by control circuitry 282 on
line 294 is of a level to cause the regulated charging signal generated
on line 264 to be of a value to effectuate such recharging. The precise
value of the regulated charging signal is maintained by way of a
feedback control loop.
When, conversely, the battery cells of battery power supply 270
are not to be recharged (e.g., during times in which transmitter
circuitry portion 252 is to be operable), the charging control signal
generated by control circuitry 282 on line 294 is of a level to cause no
regulated charging signal to be generated by charge regulator 258 on
line 264.
Accordingly, in the preferred embodiment, when transmitter
circuitry portion 252 of radiotelephone 210 is to be operative to
transmit modulated signals, control circuitry 282 generates a signal
on line 294 to prevent application of a regulated charging signal to the
battery cells of the battery power supply 270 and also to generate a
signal of the first signal level on line 300 to cause power source 216 to
21~53~
generate a signal on line 222 of a reduced level required to power only
receiver and transmitter circuitry portions 250 and 252.
Conversely, when transmitter circuitry portion 252 is not to be
operative, the charge control signal generated on line 294 is of a level
to permit a regulated charging signal to be applied to the battery cells
of battery power supply 270, and the signal of the second signal level
is generated on line 300 to cause power source 216 to generate a
signal on line 222 of a power level to permit recharging of the battery
cells of battery power supply 270. (Circuitry internal to receiver and
transmitter circuitry portions 250 and 252 prevent application of
power on line 246 to power the respective circuitry portions 250 and
252.)
Radiotelephone 210 is further shown to include input element
312 which is coupled to receiver and transmitter circuitry portions
250 and 252 by way of line 318. Similarly, display element 324 is also
coupled to portions 250 and 252, here by way of line 328.
Turning next to the partial block, partial schematic diagram of
FIG. 3, a charge regulator, here designated by reference numeral
358, is shown. Charge regulator 358 is analogous to charge regulator
258 of radiotelephone 210 of FIG. 2 and to charge regulator 58 of
electronic device 10 of FIG. 1. A charging signal similar to the signal
generated by power sources 216 and 16 of the preceding figures, is
applied to charge regulator 358 on line 446. A charge control signal
is applied to charge regulator 358 on line 494 in a manner analogous
to the manner in which the charge control signal is generated on
lines 94 and 294 of charge regulators 58 and 258 of FIGs. 1 and 2,
respectively. And, a regulated charging signal is generated on line
464 in a manner analogous to the manners in which regulated
charging signals are generated on lines 64 and 264 of FIGs. 1 and 2,
respectively.
The signal generated on line 446 is applied to a source electrode
of field effect transistor 504. The drain electrode of transistor 504 is
coupled to line 464 across resistor 510 and diode 516.
Comparator 524, configured to form a differential amplifier,
includes a positive input coupled to the left-hand side of resistor 510
- 18-
by way of resistor 530. A negative input of comparator 524 is coupled
to a right-hand side of resistor 510 by way of resistor 536. Shunt
resistors 542 and 548 are further coupled to the positive and negative
inputs, respectively, of comparator 524.
Comparator 524 generates a differential output signal on line
554 representative of differences between the signal applied at the
positive and negative inputs thereof. As the signals applied to the
positive and negative inputs of comparator 524 are indicative of the
voltage levels at the left- and right-hand side portions of resistor 510,
the signal generated on line 554 is representative of the voltage drop
across resistor 510 (and, as voltage is related to the current at the
drain electrode, the signal generated on line 554 is related to the
current at line 464).
Line 554 is coupled to a positive input of comparator 560.
Comparator 560 is also configured to form a differential amplifier. A
charge control signal generated on line 494 is applied to a negative
input of comparator 560. The differential output of amplifier 560
generated on line 566 is applied to a gate electrode of transistor 504 by
way of resistor 572. Shunt capacitor 578 is further connected between
the gate electrode of transistor 504 and ground. The loop formed
between the drain electrode of transistor 504 and the gate electrode
thereof forms a feedback loop which permits control of the current
(and, hence, the power level) of the signal generated on line 464 as the
value of the signal applied to the gate electrode of transistor 504
causes transistor 504 to operate in a conventional manner (analogous
to operation of a valve) to control the current level of the drain
electrode and line 464. And, the value of the charge control signal
applied on line 494 controls the value of the signal applied to the gate
electrode. Appropriate variation of the value of the signal generated
on line 494 results in a signal generated on line 464 to be of any
desired value.
Turning next to the schematic view of FIG. 4, a
radiotelephone, referred to generally by reference numeral 610 is
shown. Radiotelephone 610 corresponds to radiotelephone 210 shown
in the block diagram of FIG. 2. Elements of radiotelephone 210
21~0~3~
- 19-
shown in block form in FIG. 2 are disposed within the housing of
radiotelephone 610 of FIG. 4 but for rechargeable battery power
supply 270 which here is shown to comprise battery pack 614
Radiotelephone 610 is connected to variable-level power source
616 by way of lines 622 and 628 which connect power source 616 to
connecting elements of radiotelephone 610 through plug connector
630. (Connecting elements of radiotelephone 610 are hidden from
view in the figure, but correspond to connecting elements 234 and 240
of FIG. 2.) Plug connector 636 is also shown in the figure permitting
connection of power source 616 to a conventional household power
supply. (While plug connector 636 comprises a plug connector
permitting connection to a conventional household power supply,
other plug connectors permitting connection to other types of power
supplies are, of course, similarly possible.)
Because power source 616 is positioned remote from
radiotelephone 610, but connected thereto by way of lines 622 and 628,
radiotelephone 610 may be conveniently operated by a user in spite of
the connection between radiotelephone 610 and power source 616.
When radiotelephone 610 is operative to be in the "standby"
mode, a control signal generated by radiotelephone 610 on line 628
causes power source 616 to generate a signal of a relatively high
power level on line 622 to permit recharging of the battery cells of
battery pack 614 comprising a rechargeable power supply. When,
however, radiotelephone 610 is operative to transmit modulated
signals, radiotelephone 610 generates a control signal on line 628 to
cause power source 616 to generate a signal on line 622 of a relatively
low power level; the battery cells of battery pack 614 are not recharged
and the signal generated on line 622 is of a power level to permit
powering of the transmitter and receiver circuitry portions of the
radiotelephone. In such manner, overheating of radiotelephone 610
is prevented as the transmitter circuitry portions of radiotelephone
610 and recharging of the battery cells of battery pack 614 do not occur
simultaneously.
Turning next to the flow diagram of FIG. 5, an algorithm,
referred to generally by reference numeral 700 which is executable by
21q~53~
- 20 -
control circuitry of radiotelephone 210 of FIG. 2 is shown. When
executed, algorithm 700 causes control circuitry 282 to generate
control signals on lines 294 and 300 to control application of charging
currents to rechargeable battery power supply 270 (or, with respect to
radiotelephone 610 of FIG. 4, battery pack 614) and also the power
level of the signal generated by power source 216 (or, with respect to
radiotelephone 610, power source 616).
First, and as indicated by decision block 706, a determination is
made as to whether the variable-level power source is connected to
the radiotelephone. If the power source is not connected to the
radiotelephone, the no branch is taken, and the receiver and
transmitter circuitry portions 250 and 252 of radiotelephone 210 are
powered with the stored energy of battery power supply 270.
If, however, the power source is connected to the
radiotelephone, the yes branch is taken to decision block 718 and a
determination is made as to whether transmitter circuitry portion
252 is operable to transmit modulated signals. If the radiotelephone
is in the "standby" mode or transmitter circuitry portion 252 is
otherwise not to be operable, the no branch is taken, a control signal
of the first signal level is generated on line 300, as indicated by block
724, and the charge control signal generated on line 294 is generated
to be of a value, and as indicated by block 730, to-permit charge
regulator 258 to generate a regulated charging signal on line 264 to
recharge the battery cells of battery power supply 270.
If, however, transmitter circuitry portion 252 is to be operable,
the yes branch is taken from decision block 718, the control signal
generated on line 300 is of a second signal level value, as indicated by
block 736, and the charge control signal generated on line 294 is of a
signal level, as indicated by block 742 to cause charge regulator 258
not to generate a regulated charging signal on line 264. Algorithm
700 is repeated during operation of radiotelephone 210.
FIG. 6 is a logical flow diagram listing the method steps of the
method, referred to generally by reference numeral 800, of a
preferred embodiment of the present invention. Method 800 permits
powering of transceiver circuitry of a radiotelephone which is
21~053~
operable to receive operative power of either of at least two power
levels generated by a variable-level power source when the variable-
level power source is connected to the radiotelephone.
First, and as indicated by block 806, the variable-level power
5 source is releasably connected to the radiotelephone to provide
operative power to the radiotelephone.
Next, and as indicated by block 812, a rechargeable power
supply is coupled to receive a charging signal responsive to times in
which the variable-level power source is coupled to provide operative
10 power of a first power level to the electronic device.
Next, and as indicated by block 818, the transceiver circuitry is
provided with either the operative power generated by the variable-
level power source or power generated by energy stored by the
rechargeable power supply.
1~ Finally, and as indicated by block 824, a power-source control
signal is generated for application to the variable-level power source
wherein the power source control signal is of either of at least a first
signal level to cause the operative power of the variable-level power
source to be a first of the at least two power levels or of a second signal
20 level to cause the operative power of the variable-level power source to
be of a second of the at least two power levels.
Because the electronic device of the preferred embodiment of
the present invention, and the method therefor, causes the power
level of an externally-generated signal to be of a level dependent upon
25 the power needs of such electronic device, generation of excessive
amounts of heat caused as a result of applying large amounts of
power to the electronic device is avoided.
2~ A1~5 35
.
- 22 -
While the present invention has been described in connection
with the preferred embodiments shown in the various f1gures, it is to
be understood that other similar embodiments may be used and
modifications and additions may be made to the described
5 embodiments for performing the same function of the present
invention without deviating therefrom. Therefore, the present
invention should not be limited to any single embodiment, but rather
construed in breadth and scope in accordance with the recitation of
the appended claims.
