U.S. patent number 5,734,254 [Application Number 08/759,693] was granted by the patent office on 1998-03-31 for battery pack and charging system for a portable electronic device.
This patent grant is currently assigned to Hewlett-Packard Company. Invention is credited to Charles S. Stephens.
United States Patent |
5,734,254 |
Stephens |
March 31, 1998 |
Battery pack and charging system for a portable electronic
device
Abstract
A battery pack, adapter and integrated charging system for
charging a battery pack of the type used in a portable electronic
device such as a notebook computer, a cellular telephone, etc. The
battery pack includes a battery coupled through a power converter
to a secondary transformer winding. A communication link is
provided to the adapter which includes control logic and a power
selector. The adapter may be configured to provide DC or AC power
to charge a portable electronic device and the processor of a
portable electronic device may be used to control charging of an
external battery pack.
Inventors: |
Stephens; Charles S.
(Corvallis, OR) |
Assignee: |
Hewlett-Packard Company (Palo
Alto, CA)
|
Family
ID: |
25056609 |
Appl.
No.: |
08/759,693 |
Filed: |
December 6, 1996 |
Current U.S.
Class: |
320/106;
D13/107 |
Current CPC
Class: |
H02J
50/80 (20160201); H02J 50/10 (20160201); H02J
50/90 (20160201); H02J 7/025 (20130101); H02J
7/00036 (20200101); H01M 10/44 (20130101); Y02E
60/10 (20130101) |
Current International
Class: |
H01M
10/42 (20060101); H01M 10/44 (20060101); H01M
010/46 () |
Field of
Search: |
;320/2,48
;429/90,96,97,98,99,100 ;D13/107 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tso; Edward
Claims
I claim:
1. A battery pack for use with a portable electronic device,
comprising:
a housing;
a battery mounted within said housing;
a secondary transformer winding mounted within said housing for
coupling an AC power signal;
power converting means coupled between said battery and said
secondary transformer winding for converting an AC power signal
coupled by said secondary transformer winding into a DC power
signal for charging said battery;
a first communication port formed in an exterior of said housing;
and
means coupled to said battery and said first communication port for
propagating signals indicative of battery charge status from said
battery to said first communication port, said signals indicating
at least the need for charging at a first level and a second level
different from said first level, and for propagating the status
signals outside of said battery pack.
2. The battery pack of claim 1, further comprising a proximity
indicating device.
3. The battery pack of claim 1, wherein said first communication
port is an IR port.
4. The battery pack of claim 1, further comprising a second
communication port.
5. An AC adapter for use in charging a battery of the type used in
a portable electronic device, comprising:
a housing;
a first primary transformer winding mounted within said housing for
emitting an AC power signal outside of said housing;
power selecting means coupled between said primary transformer
winding and an AC input for selecting a level of power emitted from
said primary transformer winding;
a communication port for receiving battery status signals from a
battery pack in the proximity of said adapter that indicates at
least the need for charging at a first level and a second level;
and
control logic means coupled to said communication port and said
power selecting means for generating control signals that control
the charging of a battery pack in the proximity of said
adapter.
6. The adapter of claim 5, wherein said control signals are
propagated through an IR port to an exterior of said adapter to
regulate a power converter of said battery pack in the proximity of
said adapter.
7. The adapter of claim 5, further comprising proximity detecting
means for detecting the presence of a proximity indicating device
within a predefined proximity of said adapter.
8. The adapter of claim 5, further comprising:
an AC/DC converter coupled to said AC input for converting an AC
power signal to a DC power signal; and
output port means for coupling said DC signal exterior of said
adapter.
9. The adapter of claim 5, further comprising:
a second primary transformer winding mounted within said housing
for emitting a second AC power signal outside of said housing;
and
second power selecting means coupled between said second primary
transformer winding and said AC input for selecting a level of
power emitted from said second primary transformer winding.
10. A battery pack for use with a portable electronic device,
comprising:
a housing;
a battery mounted within said housing;
a secondary transformer winding mounted within said housing for
coupling an AC power signal;
power converting means coupled between said battery and said
secondary transformer winding for converting an AC power signal
coupled by said secondary transformer winding into a DC power
signal for charging said battery;
a first communication port formed in an exterior of said
housing;
means coupled to said battery and said first communication port for
propagating signals indicative of battery charge status from said
battery to said first communication and for propagating the status
signals outside of said battery pack; and
feedback control means coupled between said battery and said power
converting means for controlling an output of said power converting
means based on sensed battery status signals input from said
battery.
11. A battery pack for use with a portable electronic device,
comprising:
a housing;
a battery mounted within said housing;
a secondary transformer winding mounted within said housing for
coupling an AC power signal;
power converting means coupled between said battery and said
secondary transformer winding for converting an AC power signal
coupled by said secondary transformer winding into a DC power
signal for charging said battery;
a first communication port formed in an exterior of said housing;
and
means coupled to said battery and said first communication port for
propagating signals indicative of battery charge status from said
battery to said first communication and for propagating the status
signals outside of said battery pack;
wherein said power converting means is coupled to said
communication port in such a manner as to receive power converting
means control signals via the communication port that control the
DC power output to the battery.
12. A battery charging system, comprising:
a battery pack containing a battery;
an adapter;
portable electronic device, separate from said battery pack;
and
a communication link between said battery pack and said portable
computing device for propagating battery status information to said
portable electronic device;
wherein said adapter comprises means for simultaneously charging
said battery and said portable electronic device.
Description
FIELD OF THE INVENTION
The present invention relates to battery packs, AC adapters and
charging systems for use with portable electronic devices, such as
computers, cellular telephones, etc.
BACKGROUND OF THE INVENTION
The prior art teaches various systems for charging a battery pack
for use in a portable computing device. One such prior art system
includes a wall adapter unit connected by a cord to a battery
charger. The battery charger contains one or more vertical slots in
a top surface thereof in which battery packs are inserted for
charging. Charging is achieved through direct electrical contact to
external electrodes. A disadvantage of this design is that as new
batteries are developed for new or different portable computing
devices, new battery chargers having slots that conform to the
shape and electrode arrangement of the new batteries must be
developed.
The prior art also includes a system for providing wireless
powering of a laptop computer. This system, disclosed in U.S. Pat.
No. 5,455,466, issued to Parks et al, includes a desk top computer
that controls a power amplifier used to inductively couple power to
a portable computer. Disadvantages of this system include the
complexity and size of the computers used to control the inductive
transfer of power and that the system does not provide simultaneous
charging of a battery pack and separate portable computing
device.
Other relevant aspects of the prior art include that the prior art
does not disclose battery packs having charge control logic
provided exterior to the battery pack (i.e., in the charger) to
thereby reduce weight, cost and size of the battery pack.
SUMMARY OF THE INVENTION
Accordingly it is an object of the present invention to provide a
battery and corresponding charger that permits a battery of any
size and voltage to be charged by the charger.
It is another object of the present invention to provide a battery
charger that can simultaneously charge both a battery and power a
portable electronic device.
It is also an object of the present invention to provide a battery
charging unit that can simultaneously charge batteries of varying
size and power a portable electronic device.
These and related objects of the present invention are achieved by
use of battery pack, adapter and charging systems disclosed
herein.
In one embodiment of the present invention, a battery pack is
disclosed that comprises a battery mounted within a housing and
coupled through a power converter to a secondary transformer
winding. A communication port formed in an exterior of said housing
permits propagation of battery status signals outside of the
housing. The communication port may be implemented using infrared
technology and a proximity indicating device may be provided to
indicate the presence of the battery pack to a charger. Feedback
control logic controls an output of the power converter based on
sensed battery status signals.
In another embodiment of the present invention, an AC adapter is
disclosed that comprises a primary transformer winding mounted
within a housing for emitting an AC power signal outside of said
housing, a power selector coupled between the primary transformer
winding and an AC input for selecting a level of power emitted from
the primary transformer winding, a communication port for receiving
propagated battery status signals from a battery pack within the
proximity of said adapter, and control logic coupled to the
communication port for generating control signals controlling the
charging of a battery pack in the proximity of the adapter. The
adapter may be configured such that the control signals control the
level of an AC power signal output from the power selector or an
output of a power converter in the battery pack (in this instance
the control signals are propagated through the wireless
communication port to the battery pack), or both. The adapter may
also provide a proximity detector for detecting when a battery pack
is proximate the adapter and an AC/DC converter to produce a DC
power signal. The adapter may also be provided with a second power
selector and primary transformer winding for inductively charging
another battery pack or portable electronic device.
In yet another embodiment of the present invention, a charging
system is disclosed including a battery pack containing a battery,
an adapter, a portable electronic device separate from the battery
pack, and a communication link between the battery pack and the
portable electronic device for propagating battery status
information to the portable electronic device. The adapter may be
configured to simultaneously charge a first battery pack and a
second battery pack/portable electronic device. The communication
link is preferably IR.
The attainment of the foregoing and related advantages, features
and configurations of the present invention should be more readily
apparent to those skilled in the art, after review of the following
more detailed description of the invention taken together with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a battery pack and adapter in
accordance with the present invention.
FIG. 2 is a block diagram of a battery pack and charging system in
accordance with the present invention.
FIG. 3 is a block diagram of another battery pack and charging
system in accordance with the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1, a block diagram of a battery pack and adapter
in accordance with the present invention is shown. The battery pack
10 is suitable for use in a portable electronic device such as a
notebook computer, cellular telephones, and the like and includes a
battery 12 having a plurality of surface electrodes 13-16.
Electrode 13-14 for example, provide a supply and return voltage,
while electrodes 15-16 provide serial data transfer. The content of
this serial data may include battery status and sensing information
such as charge status, voltage level, instantaneous current, and
temperature, etc. A memory 18 may also be provided for accumulating
a history of status and sensing information.
Battery 12 is preferably a lithium ion, N metal hydride or like
battery. Both of these batteries are known in the art for their
generally compact size and ability to hold extended charges.
Lithium ion batteries are generally regarded as being lightweight.
Battery 12 also contains sensors for collection of the type of data
mentioned immediately above and such sensors are normally provided
by the battery vendor.
During charging, as discussed in more detail below, lithium ion
batteries are normally charged by a high power charge until a
threshold voltage is reached, after which a lower power charge is
applied. N metal hydride batteries are normally charged until a
predefined temperature or rate of temperature change is reached,
after which charging is more closely regulated.
Block 20 represents sensing, feedback and control logic. Block 20
is coupled to battery 12, a power converter 30 and a communication
port 24. Block 20 is represented in dashed lines because the
functions of the block can be, and in one preferred embodiment are,
provided externally to the battery pack as discussed below.
The composition of the sensing logic which receives signals from
the sensors will vary in a known manner depending on the type of
battery used at battery 12. The output of the sensing logic
provides feedback signals to the control logic which in turn
regulates AC/DC power converter 30 by setting known parameters
therein. For example, in the case of a lithium ion battery, after a
threshold voltage across battery 12 is sensed, the control logic in
block 20 (or block 50 of adapter 40 as discussed below) propagates
control signals to the power converter 30. These control signals
cause power converter 30 to reduce the rate at which the battery is
being charged and to discontinue charging once a full charge is
reached and sustained. In the case of a N metal hydride battery, a
predetermined rate of change of battery temperature, when battery
voltage is within a specified range, causes the control logic 20
(or 50 of adapter 40) to propagate similar control signals to power
converter 30 to achieve a regulated reduction in charging level.
The regulation of lithium ion and N metal hydride batteries is
known in the art.
Power converter 30 is coupled to a secondary transformer winding 32
and to battery 12. The configuration of power converter 30 depends
on the type of battery provided at battery 12, and may include
voltage and drive level control, current limiting, decoupling
relays and stepped or ramped voltage, amongst other known
configurations. Charging specifications are provided by battery
manufacturers.
The communication port 24 is preferably implemented as a wireless
IR port (which is conventionally implemented with LEDs and
photodetectors) though other wireless and wired techniques may be
used and are included within the present invention. It should be
recognized that the entire exterior housing of battery pack 10 or a
subset thereof may be made of IR propagating media to eliminate
communication alignment limitations.
Battery pack 10 also includes a proximity indicating device 38. The
device 38 operates in conjunction with a proximity detector 68 in
adapter 40 to indicate to the adapter that a battery pack is
positioned for charging. Proximity indicating device 38 may be a
magnet, while detector 68 is a magnetic sensor propagating a binary
signal to controller 50. Additional proximity indicating devices
may be provided within battery pack 10, for example, on the
opposing surface, to further reduce alignment limitations.
Adapter 40 includes the controller 50 which is preferably an Intel
8051 or like processor. Controller 50 is coupled to a communication
port (configured as an IR port) 54, proximity detector 68, a power
selector 60 and an AC/DC converter 70. In one preferred embodiment
of battery pack 10, the sensing, feedback and control logic of
block 20 are provided in the controller 50. In this embodiment,
sensed battery conditions are propagated from battery 12 through IR
port 24 to controller 50 in adapter 40. The controller provides
feedback control signals through the wireless communication ports
24,54 to power converter 30. Such a configuration, in which the
control logic for battery pack 10 is provided external to the
battery pack, achieves a basal level battery that has more
universal application and is relatively inexpensive to
manufacture.
Power selector 60 provides power amplification levels and may be
configured to facilitate the voltage and current limiting
properties discussed above for power converter 30. The output of
power selector 60 is propagated to a primary transformer winding 62
(which forms a complete transformer with secondary transformer
winding 32) from where it is inductively coupled to secondary
transformer winding 32 in battery pack 10.
AC/DC converter 70 is preferably designed to receive an input AC
signal ranging from 90-260 V and to produce a regulated output
consisting of a positive voltage and corresponding negative return
voltage. In one preferred embodiment for use with a conventional
notebook computer, such as those of Hewlett-Packard Company, the
output voltage is preferably 12 V DC.
Referring to FIG. 2, a block diagram of a battery pack and charging
system in accordance with the present invention is shown. This
system provides simultaneous charging of a battery pack and
portable electronic device.
Battery pack 110 is similar to battery pack 10 of FIG. 1 in that it
includes a battery 112 coupled to external electrodes 113-116, a
power converter 130, optional control logic 120, a proximity
indicating device 138 and a communication port 124. Battery pack
110 also includes a second communication port 125. Both of these
ports 124,125 are preferably configured as wireless IR ports. Port
125 permits communication with a like port of a portable computing
device 190 or a docking station 191 for such a portable computing
device. At least one of the computing device and docking station
provides a wireless communication port 192 or 193 to achieve
communication with battery pack 110. The communication port may be
configured in the docking station and propagate signals via
conductor 181 or be provided directly in the portable computing
device 190 (with the docking station being configured so as to not
obstruct communication between the device 190 and battery pack
110.
The establishment of communication between a portable computing
device 190 and a battery pack to-be-charged permits utilization of
the processor 195 for control of charging and thus eliminates the
need for same in control block 120 or 150. To achieve requisite
control with processor 195, the processor is configured to receive
sensed signals from battery 112 (output through port 125) and to
generate power converter 130 control signals based on the sensed
signals. The control signals are propagated directly to power
converter 130 (i.e., block 120 merely act as a pass through for
sensing and control signals). When battery 112 is fully charged,
the processor disables power converter 130 and communicates through
port 124 to the adapter 140 to disable its charging function.
Though use of processor 195 may achieve some advantages, retaining
control logic in block 50 is advantageous in that it permits
charging of a battery pack when a portable computing device (and
the processor therein) are not available.
The adapter 140 is analogous to adapter 40 of FIG. 1 and includes a
primary transformer 162, a power selector 160, an AC/DC converter
170, a communication port 154 and a proximity detector 168. A DC
output of adapter 140 (and 40 of FIG. 1) may be used to power a
portable computing device coupled to a DC output port.
Referring to FIG. 3, a block diagram of another battery pack and
charging system in accordance with the present invention is
shown.
Adapter unit 240 provides wireless charging of a battery pack 210
and a portable computing device 290. To provide this feature,
adapter 240 includes first and second power selectors 260,261 and
first and second primary transformers windings 262,263. Primary
transformer winding 263 couples electrical energy to secondary
transformer winding 283 for powering the portable computing device
and for charging a battery therein. An AC/DC converter-regulator
284 converts the input AC power signal to DC for use by portable
computing device circuits, including a known battery charging
circuit. Feedback from these circuits is utilized by the processor
295 to control the charge output from AC/DC converter 284 in a
manner discussed above for power converter 30 of FIG. 1. Portable
computing device 290 also includes a proximity detector 286 and a
communication port 285.
Adapter 240 includes a proximity detector 268, proximity indicating
device 269 and two wireless communication ports 254,255 for
communicating with the battery pack 210 and portable computing
device 290, respectively. These components are as discussed above
with reference to FIG. 1. Block 250 represents control logic for
charging a battery pack (as discussed above for controller 50) and
battery pack 210 is analogous to battery pack 10.
It should be recognized that adapter 240 could be used to charge
two battery packs, instead of one battery pack and one portable
electronic device. In this instance, adapter 240 would be provided
with a second proximity detector for detecting the presence of the
second battery pack and known control logic in block 250 for
regulating charging of the second battery pack.
While the invention has been described in connection with specific
embodiments thereof, it will be understood that it is capable of
further modification, and this application is intended to cover any
variations, uses, or adaptations of the invention following, in
general, the principles of the invention and including such
departures from the present disclosure as come within known or
customary practice in the art to which the invention pertains and
as may be applied to the essential features hereinbefore set forth,
and as fall within the scope of the invention and the limits of the
appended claims.
* * * * *