as) United States
`a2) Patent Application Publication co) Pub. No.: US 2011/0148344 Al
`
` Manoret al. (43) Pub. Date: Jun. 23, 2011
`
`
`US 20110148344A1
`
`Publication Classification
`
`(
`
`51)
`
`Int. Cl.
`(2006.01)
`HO02J 7/00
`(52) US. C1. eeeecessessesseessessessessesecueesceucenecneaneats 320/103
`
`(57)
`
`ABSTRACT
`
`Achargerfor rechargingthe batteries of a portable electronic
`device even when no external power source is available. A
`battery orcell is installed within the charger, and when no
`access is available to a fixed power source into which the
`charger can be plugged,the internal battery or cell can be used
`to recharge the electronic device. The internal battery can be
`a primary battery or a secondary battery.In the latter case, the
`internalbattery can be maintained in a charged state by means
`ofcircuitry which, whenthe chargeris pluggedinto the exter-
`nal power source, charges the internal battery as well as the
`battery of the electronic device. The external power source
`can be either an AC power wall socket, in which case the
`charger includes AC/DC voltage conversion circuits, or a car
`lighter socket, or the DC output of a conventional wall
`
`(54) BATTERY POWERED CHARGER
`(75)
`Inventors:
`Dror Manor, Hertzlia IL); Amnon
`.
`.
`:
`Saar, Tel Aviv (IL); Guy
`Weinstein, Neve Monosson(IL);
`Daniel Breiting, Zerufa (IL); Hans
`Vercoulen, Helden (NL)
`
`(73) Assignee:
`
`Techtium Ltd., Tel Aviv (IL)
`
`(21) Appl. No.:
`
`12/520,093
`
`(22)
`
`PCTFiled:
`
`Dec. 20, 2007
`
`(86) PCT No::
`
`PCT/IL2007/001582
`
`§ 371 (¢)(1),
`Jun. 4, 2010
`(2), (4) Date:
`Related U.S. Application Data
`
`(60) Provisional application No. 60/875,814,filed on Dec.
`20, 2006, provisional application No. 60/996,220,
`filed on Nov. 7, 2007.
`
`charger.
`
`1
`
`APPLE 1117
`Apple v. GUI
`IPR2021-00470
`
`APPLE 1117
`Apple v. GUI
`IPR2021-00470
`
`1
`
`

`

`Patent Application Publication
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`Jun. 23, 2011 Sheet 1 of 2
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`US 2011/0148344 Al
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`FIG.1
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`2
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`Patent Application Publication
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`Jun. 23, 2011 Sheet 2 of 2
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`US 2011/0148344 Al
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`3
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`US 2011/0148344 Al
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`Jun. 23, 2011
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`BATTERY POWERED CHARGER
`
`FIELD OF THE INVENTION
`
`[0001] The present invention relatesto the field of charging
`devices for portable electronic equipment, especially those
`for use with mobile telephones.
`
`BACKGROUND OF THE INVENTION
`
`Portable electronic devices generally use internal
`[0002]
`rechargeable batteries for operation. In order to maintain the
`internal batteries in a state of charge, the device is generally
`rechargedat regular intervals using a wall mains adaptorunit,
`whosefunction is to convert the comparatively high voltage
`AC mains voltage available at wall sockets, to a low voltage
`suitable for inputting to the device’s charging input. At the
`same time, such a wall charger often regulates the charging
`profile to the internal batteries of the electronic device, in
`order to maximize charging efficiency, and to ensure safe
`charging. Other types of charger unit utilize the low voltage
`DC powersource available in automobiles, such as the ciga-
`rette lighter socket, in order to charge the device’s internal
`batteries. Such external powersources will be knownasfixed
`power sources in this application. Furthermore, the term
`“wall charger” will generally be used in this application to
`include any type of charger which is generally plugged into a
`fixed powersource.
`[0003] However, anAC mains powersource, ora carlighter
`socket, is not always available when the battery of the por-
`table device requires charging, and the user thenhasto either
`carry with him spare charged batteries, which could be a
`safety hazard, or must purchase such batteries, which is not
`always a simple task, as many portable devices, and espe-
`cially mobile phones, use dedicated battery packs which are
`not widely available. Even then, such battery packs are often
`supplied in a non-chargedstate.
`[0004] One solution to this problem is described in U.S.
`Pat. No. 6,479,963, for “Rechargeable Battery Packs”, to the
`inventors of the present application, in which a novel battery
`pack is disclosed which can be fitted with a widely available
`primary cell to recharge the rechargeable cells of the portable
`device. Another solution is described in co-pending PCT
`Application published as International Patent Application
`No. WO/2006/095353 for “Portable Battery Operated Power
`Supply”, also to inventors ofthe present application, in which
`a special external battery pack, preferably containing a
`rechargeable cell, is used to enable recharging ofthe device at
`any location.
`[0005] Each of these solutions has its own disadvantage.
`The former requires that the device be equipped with the
`specialbattery pack such as that describedin the patent, while
`the latter requires of the device owner to carry with him/her
`the special external battery pack, and to ensure that the exter-
`nal battery pack is kept charged by connectingit to a conven-
`tional wall charger at the required intervals.
`[0006] There therefore exists a need for a portable charging
`system which overcomesat least some of the disadvantages
`of prior art systems and methods, to enable the user of por-
`table electronic devices to simply recharge the internal bat-
`teries of the device, without the need to have accessto a fixed
`source of charging power.
`[0007] Though the term battery is strictly speaking under-
`stood to mean a packofat least two cells, in common usage
`the term is also understood to mean a single cell. Conse-
`
`quently, these two terms, battery and cell, may have been used
`interchangeably in this application, and may also have been
`thuswise claimed, and the numberofcells in the device ofthe
`invention is not meantto be limited by use of one or the other
`term.
`
`[0008] The disclosures of each of the publications men-
`tioned in this section and in othersections ofthe specification,
`are hereby incorporated by reference, each in its entirety.
`
`SUMMARY OF THE INVENTION
`
`[0009] The present invention seeks to provide a new device
`for providing powerto a portable electronic device, either for
`poweringthe portable electronic device, or for recharging the
`batteries of the portable electronic device when no access to
`an external fixed power source is available. The invention is
`based on the use ofan external charger, such as a wall charger,
`with an associated auxiliary battery orcell, such that when no
`access is available to a fixed power source into which the
`external charger can be plugged, such as a wall powerpoint,
`ora car lighter socket, the associated auxiliary battery orcell
`can be used to recharge the battery of the electronic device.
`The charging device ofthe present invention preferably incor-
`porates charge control and conversion circuitry for converting
`the input voltage supplied from the external source to that
`required to charge the associated auxiliary battery or cell, and
`to that required for input to the external charger input socket
`ofthe electronic device, for powering the electronic device or
`for charging the electronic device’s internal battery. The
`charge control and converter circuit is preferably a bidirec-
`tional converter, in order to control both the charging current
`from the external source into the associated auxiliary battery,
`and to control the discharge current from the associated aux-
`iliary battery into the portable electronic device. The circuitry
`ofthe battery powered chargerofthe present invention differs
`from that of prior art multi-source chargers, such as that
`described in U.S. Pat. No. 7,166,987 to K. S. Lee etal, for
`“Portable Charger for Mobile Phone”, in that the use of a
`single bi-directional DC/DC converter as the charge control-
`ler for the auxiliary battery enables the provision of a simpler
`charger structure. The DC output from the external source,
`whether directly from a car socket, or from an AC/DC wall
`charger, can be at such a voltage level that it can be supplied
`directly to the mobile electronic device power input socket,
`or, by means of a single bidirectional DC/DC voltage con-
`verter, to the auxiliary battery. This same DC/DC converter,
`by virtue of its bidirectionality, is able also to handle, when
`required, the flow of current and the voltage conversion from
`the battery out to the mobile device, such that effectively all of
`the charge control and conversion functions are performed
`with a single bidirectional controlcircuit.
`[0010] The charge control circuit also preferably incorpo-
`rates battery chemistry detection circuitry, such as that
`described in co-pending International Patent Application
`PCT/IL2007/001532 for “Charging Methods for Battery
`Powered Devices”, or in similar battery chemistry detection
`circuits with simpler algorithms, as is knownin the art, such
`that if the associated auxiliary battery or cell is detected as
`being primary, recharging thereof is disenabled. This feature
`is even more important in a battery powered wall charger than
`in a conventional battery charger, since the additional heat
`generated in a battery powered wall charger when operating,
`increases the internal temperature, and the possibility that a
`primary cell being charged therein may fail catastrophically
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`Jun. 23, 2011
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`[0011] Accordingtoafirst preferred embodiment, the aux- not. This then ensuresthat the internal battery of the charger
`
`remains charged even whenthe chargeris in stand-by mode.
`iliary battery or cell is installed within the external charger
`[0015] The circuits ofthe wall chargerofthe present inven-
`itself, preferably within a dedicated battery cavity. An advan-
`tion are generally multifunctional and bidirectional, in that
`tage of this embodimentoverthe prior art devices described
`they have to be capable of performing at least some of the
`hereinaboveis that the electronic device user generally car-
`following functions:
`ries a normal wall charger, to enable the electronic device to
`(1) When the charger is plugged into a fixed power source,
`be charged in the conventional manner. Therefore, the use of
`whether an AC wall powersource, or a car socket, or the DC
`the charger ofthis embodimentofthe present invention, while
`output of a conventional wall charger unit, the circuits should
`providing the user with an in-the-field charging capability,
`preferably convert the voltage up or down, depending on the
`does not involve the need to carry any additional equipment
`voltage supplied, and the voltage required,to a suitable level
`which the user would not otherwise have to carry with him/
`to provide current for charging or powering the electronic
`her.
`device when it is attached.
`(11) When the chargeris pluggedinto a fixed powersource, (as
`described above) the circuits should be able to convert the
`voltage to a suitable level to provide current for charging the
`auxiliary battery or cell of the wall charger.
`(111) The circuits should preferably ascertain whether the aux-
`iliary battery or cell of the wall charger is primary or second-
`ary, so that if primary, the internal battery charging circuit is
`not enabled.
`(iv) Whenan electronic device is attached to the wall charger,
`and the charger is not connected to a fixed power source, the
`circuits should enable the device to draw charging current
`from the auxiliary battery, whether primary or secondary.
`(v) Since the wall charger auxiliary battery, if a secondary
`battery, needs to be both charged and discharged, the circuitry
`which controls these functions preferably has bidirectional
`characteristics, such as is described in PCT Application No.
`PCT/IL2006/000317, published as
`International Patent
`Application No. WO/2006/095352 for Bidirectional Battery
`Charge Controller, incorporated herein by reference in its
`entirety. If the wall charger is intended for use only with a
`primary battery, then bidirectionality is not required.
`[0016] There is thus provided in accordance with a pre-
`ferred embodimentof the present invention, a charger for a
`battery operated electronic device, the charger comprising:
`(i) an input for connection to an external power source sup-
`plying currentata first voltage,
`(11) an output for connectionto the battery operated electronic
`device,
`(111) circuitry for supplying the electronic device with current
`when the charger is connected to the external source,
`(iv) a cavity for mounting in the chargerat least one battery
`having a terminal voltage different from thefirst voltage, and
`different from the voltage required for inputting to the elec-
`tronic device, the battery supplying the electronic device with
`current when the charger is not connected to the external
`powersource,
`(v) a bidirectional converter and charge controller adapted to
`control current supplied from theat least one battery mounted
`in the charger to the electronic device, and to control current
`flowing into the at least one battery when the charger is
`connected to the external power source, and
`(vi) circuitry for detecting the chemistry of least one battery.
`[0017]
`In the above described charger, the bidirectional
`converter and charge controller may preferably be further
`adapted to convert the first voltage to a voltage suitable for
`charging the at least one battery, and to convert the terminal
`voltage to a voltage suitable for inputting to the electronic
`device. Additionally, the external power source can simulta-
`neously cause currentto charge the at least one battery, and to
`supply the electronic device with current. Furthermore, the
`current supplied by the chargerto the electronic device may
`preferably be utilized to perform at least one of operating the
`electronic device and charging the battery of the electronic
`device.
`
`[0012] According to a second preferred embodimentof the
`present invention, the associated auxiliary battery or cell and
`its charge control circuitry are not housed within the external
`charger unit itself, but are contained within a separate hous-
`ing, which can be connected to a conventional external
`charger by meansofa flying lead. Connection to the portable
`electronic device is performed in the usual manner, through
`the charging input socket of the device, either by means of a
`plug, or by meansof another flying lead. This embodiment
`differs from the first embodimentin thatthe auxiliary battery
`is housed in a compartmentseparate from that of the external
`charger circuits. In that respect, the external charger output
`can be considered as being equivalent to the wall source of
`power, or to the car lighter socket source of power.
`[0013] The auxiliary battery of the wall charger of the
`present invention may be either a primary cell, which is
`readily available from numerous sources for replacement
`when expended, or a rechargeable cell, in which case, the
`chargercircuits can be arranged such that, once the presence
`of a secondary cell has been detected, the cell is maintained
`ready for use in a charged condition,either by being charged
`if necessary, or by being just trickle charged if already essen-
`tially fully charged, every time that the wall charger is con-
`nected to the fixed power source.
`[0014] According to a further preferred embodimentofthe
`present invention, the presence of a battery in the charger
`provides it with an advantage over conventional chargers, in
`enabling easier compliance with the current policy of reduc-
`ing “stand-by power”of electronic devices. If the associated
`battery is fully charged, the circuitry of the charger of the
`present invention need only be powered up whenthere is need
`to provide powerto the portable electronic device. The pres-
`ence of the on-board battery enables the charging circuits of
`the charger to be completely disconnected from the external
`source, such that no stand-by powerat all is used from the
`wall socket or from the car socket. The internal battery can be
`used to power a very low-powerdetection circuit for moni-
`toring the portable electronic device for renewed power
`demand. Once such a demandis detected, the charging cir-
`cuits can be reconnectedto the external source, and can draw
`powerfrom the external source as needed. This is in contrast
`to conventional chargers, which generally have to be left
`connected in a stand-by status to the external source, drawing
`a trickle charge current whose need may not be immediate,
`but which consumes typically 250 mW for a small wall
`charger unit typically of the order of 5 Watts or less. Addi-
`tionally, the detection circuits can also monitor the state of
`charge of the on-board chargerbattery, either by meansofits
`terminalvoltage,or by the elapsed time since the last charging
`operation, and can then reconnect the external source when
`the state of charge falls below a predeterminedlevel, regard-
`less ofwhetherthe electronic device has demandedcurrent or
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`US 2011/0148344 Al
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`Jun. 23, 2011
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`[0018] There is further provided in accordance with yet
`another preferred embodiment of the present invention, a
`charger as described above, wherein the converter and charge
`control circuit further comprises circuitry to prevent supply of
`charging currentto the at least one battery when the chargeris
`connected to the external power source.
`[0019]
`In accordance with still another preferred embodi-
`mentof the present invention, the circuitry for detecting the
`chemistry of the at least one battery may preferably be
`adapted to prevent supply of charging currentto theat least
`one battery when the battery chemistry detection circuitry
`determines thattheat least one battery is a primary battery. In
`all ofthe above charger embodiments, theat least one battery
`mounted within the charger
`is preferably replaceably
`mounted. Additionally, the charger may further comprise
`conversion circuitry for converting the voltageofthe external
`power source to that suitable for inputting to the electronic
`device.
`
`Inconnection with the above described chargers, the
`[0020]
`external power source may preferably be either an AC mains
`powersource, or the low voltage DC output of a conventional
`wall charger, or the output of a car lighter socket.
`[0021] There is further provided in accordance withstill
`another preferred embodiment of the present invention, a
`charger for a battery operated electronic device, comprising:
`(i) an input for connection to an external powersource,
`(i1) an output for connectionto the battery operated electronic
`device,
`(iii) a cavity for mounting at least one battery within the
`charger which can supply the electronic device with current
`when the charger is not connected to the external power
`source: and
`
`(iv) control circuitry powered by theat least one battery, for
`disconnecting the charger from the external source when the
`at least one battery is fully charged and when the electronic
`device is not drawing current from the charger.
`[0022]
`In such a charger, the at least one battery may be
`either a primary or a secondary battery. Furthermore, the
`control circuit may preferably be adapted to monitor the
`current drawnbythe portable electronic device, and to recon-
`nect the charger to the external source when such current
`demand exceedsa predeterminedlevel, or to monitorthestate
`of charge of the at least one battery, and to reconnect the
`charger to the external source whenthe state of charge falls
`below a predeterminedlevel. In the latter case, the state of
`charge is monitored by monitoringat least one ofthe terminal
`voltage of the at least one battery, and the elapsed time since
`the at least one battery was charged.Finally, in such chargers,
`the external source maypreferably be the mains supply, and
`disconnection of the charger from the external source essen-
`tially eliminates the stand-by current drawn from the mains
`supply.
`Inany ofthe above described charger embodiments,
`[0023]
`the charger may preferably be in a physically separate hous-
`ing from the electronic device.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0024] The present invention will be understood and appre-
`ciated more fully from the following detailed description,
`taken in conjunction with the drawings in which:
`[0025]
`FIG.1 illustrates schematically a wall charger, con-
`structed and operative accordingto a first preferred embodi-
`mentofthe present invention, and its connection to a portable
`electronic device;
`
`FIG. 2 is a schematic block diagram showing one
`[0026]
`preferred embodiment of the internal circuitry of the wall
`charger of the present invention;
`[0027]
`FIG.3 illustrates schematically a wall charger, con-
`structed and operative according to a second preferred
`embodimentof the present invention, differing from that of
`FIG.1 in that the auxiliary battery is mounted in a housing
`separate from the external charger; and
`[0028]
`FIG. 4 is a schematic block diagram showing a
`preferred embodimentofthe internal circuitry of the battery
`charger of the FIG.3.
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`[0029] Reference is now madeto FIG.1, which illustrates
`schematically a wall charger 10, constructed and operative
`according to a first preferred embodiment of the present
`invention, The wall charger preferably has conventional
`power pins 12 for inserting into a wall socket (not shown),
`though it may also use a conventional plug on the end of a
`flying lead cable, or a push-in plug for use with a cigarette
`lighter socket in a car. A cable 13 provides connection to a
`mobile telephone 14, used as an example ofa portable elec-
`tronic device which can be charged by the wall charger. The
`output may equally well be provided in the form ofa cradle in
`which the phone or other electronic device sits without a
`connection cable. The wall charger 10 differs, however, from
`a conventional wall charger in that it also contains a battery
`cavity 15, inside ofwhich can be installed one or more cells or
`batteries 16, which are preferably secondary. Alternatively
`and preferably, primary cells or batteries may be used, this
`being understoodto include a fuel cell also. The wall charger
`can be used in the conventional manner, wherebythe cable 13
`is plugged into the charging socket 17 ofthe phone 14, andthe
`phoneoperated or the internal battery of the phone charged
`from the fixed power supply. At the same timethat the wall
`charger is operating the phone or charging the phone’s inter-
`nal battery, it can also charge the wall charger internal battery
`16, if it is a secondary battery, so as to maintainit in a state of
`full charge. If it is desired to operate the phone or charge the
`phonebattery in a situation where no fixed powersource is
`available into which to plug the wall charger, then the wall
`charger is connected to the phone by meansofits cable 13, or
`by means ofmounting into the charging cradle, and the phone
`is supplied with current from the wall charger’s internal bat-
`tery 16. The internal circuitry ofthe wall chargeris preferably
`designedto prevent charging ofits internal battery 16 ifitis a
`primary battery.
`[0030] Reference is now madeto FIG.2, whichis a sche-
`matic block diagram showing one preferred embodimentof
`the internal circuitry of the wall charger 10 of the present
`invention shownin FIG. 1. The comparatively high AC mains
`voltage, input through the powerpins 12 from the fixed power
`source, is first preferably converted down to a comparatively
`low DC voltage in the AC/DC converter circuit 20. This DC
`voltage is preferably chosen to be suitable for direct applica-
`tion to the powerinput socket ofthe mobile device.In the case
`of a “wall charger” for plugging into an automobile cigarette
`lighter socket, the circuit 20 would be a DC-DC converter,
`which converts the 12 V DC input from the cigarette lighter
`socket to a preferably lower DC voltage output for use
`directly at the input to the mobile device. In the case that the
`external source ofpoweris a conventional wall charger which
`provides a low voltage DC output, the AC/DC convertercir-
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`cuitry 20 may be omitted since the external power source
`contains these functions. This last embodimentis described
`further in the embodiments of FIGS. 3 and 4. The converter
`circuit 20 is preferably configured as a current source,as is the
`usualcase in battery charging adapters, simply driving charge
`current into the power input socket of the phone or other
`device connected to the charging cable 13. A current sensing
`resistor 24 preferably provides a feedback sense signal 21 to
`the AC/DC converter circuit 20, to limit the charge current it
`can supply to the phoneor other device.
`[0031] The DC output of the converter circuit 20 is also
`preferably connectedto a bidirectional DC/DC converter and
`charge control circuit 22, which is directly connected to the
`internal battery 16 of the wall charger. The bidirectional con-
`verter and charging circuit 22 controls the flow of charging
`current from the DC output ofthe AC/DC convertercircuit 20,
`or from the DC power source whenapplicable, into the inter-
`nal battery 16 when the charger is plugged into the external
`power source, and converts the voltage to that suitable for
`charging the internal battery 16. The DC/DC converterpref-
`erably includes a battery chemistry detection circuit 26, such
`that charging current can be disabled ifthe circuit detects that
`the internal battery 16 is not a secondary battery, or is a
`secondary battery but is in a condition that indicates that
`charging would not be advised.
`[0032] The DC/DC converter also controls the flow of
`charging current from the internal battery 16 to the phone or
`other device through the charging cable 13, when the charger
`is not pluggedinto the external powersource, and performs
`the voltage conversion to enable the internal battery to power
`the mobile device. The bidirectional charge control circuit 22
`is thus functional to fully control the flow of current into and
`out ofthe internal battery 16 of the charger, and to convert the
`voltages to levels suitable for charging the battery 16 or for
`powering the mobile device 14. An optional STATUSsignal
`line 23 maypreferably be providedto notify the charge con-
`trol and conversion circuit 22 when the wall charger is
`plugged into an external power source, so that it can enable
`charging of the internal battery 16, but may disable discharg-
`ing thereof. This feature may be useful since the external
`power source, when plugged in, can generally supply all of
`the current required by the phoneor other mobile device, and
`there may be no needto draw current from theinternalbattery.
`With or without the STATUSsignal input, the battery pow-
`ered charger of the present invention also differs from those
`generally described in the priorart, in that the circuit arrange-
`ment ofthe present invention, when pluggedinto the external
`powersource, is able to both recharge its own internal battery
`16, and to supply the phoneor other mobile device 14 with
`current for operating or for charging its own internal battery.
`[0033]
`In embodiments of the charger which are intended
`only for use with a primary battery, the bidirectional charging
`circuit 22 can be replaced by a unidirectional circuit which
`needs to control only the flow of charging current from the
`internal battery 16 out to the charging cable 13.
`[0034] Although for clarity, each of the circuit functions
`have been schematically shownin FIG.2 as separate blocks,
`it is to be understood that in practice, all or some of the
`functions may preferably be performed by one multi-func-
`tional circuit.
`
`[0035] Reference is now madeto FIG.3, which is a sche-
`matic illustration of a further preferred embodiment of the
`battery powered charger 30 of the present invention. The
`charger contains an auxiliary battery or cell or cells 32,
`
`replaceable ifneeded, and charge control circuitry (not shown
`in FIG.3) for controlling flow of current out of this battery or
`cell to the mobile telephone 14 (used as a non-limiting
`example of the portable electronic device), andinto this bat-
`tery or cell when charged by the external source. This
`embodimentis thus similar in concept to that shown in FIGS.
`1 and 2, with the difference that in this embodiment, use is
`made ofa conventional wall charger 31, such asthat generally
`supplied with the phone14,as the external powersource. This
`conventional wall charger supplies a low DC voltage both for
`powering the mobile phone 14 or charging its internal battery,
`and for charging the auxiliary battery or cells 32 ofthe battery
`powered charger 30 of this embodiment. In the preferred
`example shown in FIG. 3, the battery powered charger 30
`contains twocells, but it could equally well contain a single
`cell or battery, or more than two cells. The advantageofthis
`embodimentis that the battery powered charger30 is then an
`independentunit, which can be providedas an optional acces-
`sory in addition to the normal wall charger 31 ofthe device.
`The battery powered charger30 is preferably connected to the
`charging port 17 ofthe portable electronic device by means of
`a cable 33. In order to provide interchangeability with the
`conventional charger 31, the plug 34 provided on the end of
`this cable is preferably of the same type as the plug 35 pro-
`vided on the conventional wall charger of the electronic
`device. The conventional wall charger can thus be used to
`powerthe phoneor charge the phone’sinternal battery in one
`of two different modes; either with the conventional wall
`charger pluggeddirectly into the phone, or with the conven-
`tional wall charger feeding the battery powered charger 30 of
`this embodiment, which then operates in a feed through
`charging configuration.
`[0036] Reference is now madeto FIG.4, whichis a sche-
`matic block diagram showing one preferred embodimentof
`the internal circuitry of the battery powered charger 30 of the
`embodimentof FIG. 3 of the present invention. The circuit
`structure is essentially similar to that of FIG. 2 except that the
`AC/DC converter circuitry 20 of the embodiment of FIG. 2
`now preferably resides within the conventional wall charger
`31 of FIG. 3. The DC output current from the conventional
`wall charger 31 is preferably input from its cable plug 35
`through an input socket 36. The conventional wall chargeris
`preferably configured as a current source,as is the usual case
`in battery charging adapters, simply driving charge current
`from the input socket 36, straight through the battery powered
`charger30, and into the charging input socket 17 ofthe phone.
`A current sensing resistor 44 may preferably be provided to
`supply a feedback sense signal 41 back to the conventional
`wall charger 31, to limit the charge currentit can supply to the
`phone.
`[0037] The DC output of the conventional wall charger
`external power source is also connected to a bidirectional
`DC/DC converter and charge control circuit 42, which is
`directly connected to the internal battery 32 of the battery
`powered charger. The DC/DC converter preferably includes a
`battery chemistry detection circuit 46, such that charging
`current can be disabled if the circuit detects that the internal
`battery 32 is not a secondary battery, or is a secondary battery
`but is in a condition that indicates that charging would not be
`advised. The bidirectional converter and charging circuit 42
`controls the flow of charging current from the input DC power
`source into the internal battery 32 when the battery powered
`chargeris connected to the conventional wall charger external
`power source, and converts the voltage to that suitable for
`charging the internal battery 32. It also controls the flow of
`charging current from the internal battery 32 to the phone or
`other device through the charging cable 33, when the battery
`powered charger is not connected to the conventional wall
`
`7
`
`

`

`US 2011/0148344 Al
`
`Jun. 23, 2011
`
`charger external powersource, and performsthe voltage con-
`version to enable the internal battery to power the mobile
`device. The bidirectional charge controller 42 is thus func-
`tional to fully control the flow of current into and out of the
`internal battery 32 of the battery powered charger, and to
`convert the voltagesto levels suitable for charging the battery
`32 or for powering the mobile device 14. An optional STA-
`TUSsignal line 43 may preferably be providedto notify the
`charge control circuit 42 when the wall charger is plugged
`into an external powersource, so thatit can enable charging of
`the internal battery 16, but disables discharging thereof.
`[0038]
`In embodiments of the charger which are intended
`only for use with a primary battery, the bidirectional converter
`and charging circuit 42 can be replaced by a unidirectional
`circuit which needs to control only the flow of charging cur-
`rent from the internal battery 32 out to the charging cable 33.
`[0039]
`Itis appreciated by personsskilledin the art that the
`present invention is not limited by what has been particularly
`shown and described hereinabove. Rather the scope of the
`present i