United States Patent [191
`Hakkarainen
`
`US 00564871 1A
`[11] Patent Number:
`[45] Date of Patent:
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`‘
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`r
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`1
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`5,648,711
`Jul. 15, 1997
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`[54] METHOD AND SWITCHING
`ARRANGEMENT FOR IDENTIFYING THE
`
`CHARGER OF RECHARGABLE BATTERIES
`0F PORTABLE DEVICES
`
`4,024,528
`4,634,903
`
`5/1977 Boggs et a1. .......................... .. 340/310
`1/1987 Montorfano . . . . . .
`. . . .. 307/571
`
`izhailtien et el
`
`, 5,506,490 4/1996 DeMuro .................................. .. 320/23 IISSOll ..... ..
`
`
`
`[75] Inventor: Kalle Hakkarainen, S2110, Finland
`
`FOREIGN PATENT DOCUMENTS
`
`[73] Assignee: Nokia Mobile Phones Ltd., Sale,
`Finland
`
`[21] Appl. No.: 434,934
`_
`_
`May 4’ 1995
`[22] Elm’
`[30]
`Foreign Application Priority Data
`
`Fmlaud .................................. .. 942271
`[PI]
`May 16, 1994
`[51] Int. Cl.6 .................................................. .. H01M 10/44
`[52] U.S. Cl. ............................................... .. 320/2; 323/283
`[58] Field of Search ................................... .. 323/282, 283,
`323/284, 351; 320/2, 5, 15, 23
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`0038877 11/1981 European Pat. 01f. ....... .. H02J 13/00
`0409226A3 1/1991 European Pat. on. ......... .. H02] 3/00
`3528659A1 2/1987 Germany ........................ .. H02] 7/00
`Primary Examiner-Peter S. Wong
`Assistant Examiner-Gregory J. Toaley, Jr.
`Attomey, Agent, or Finn-Penman & Green, LLP
`[57]
`ABSTRACT
`
`The object of the Invention is a method and a switching
`arrangement for identifying the charger of the rechargeable
`batteries of portable devices. In the solution according to the
`inventie11_the eharger transmits the identi?cation ef the
`charger we a ehargmg cable by swltehmg the ehargmg
`voltage on and off by using a certain pulse ratio, pulse
`length, or pulse count. The solution according to the inven
`tion can be applied in mobile phone sets.
`
`3,610,828 10/1971 Girard et a1. ....................... .. 179/15 s
`
`13 Claims, 2 Drawing Sheets
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`Apple 1014 - Page 1
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`US. Patent
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`Jul. 15, 1997
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`Sheet 1 0f 2
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`5,648,711
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`Apple 1014 - Page 2
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`

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`U.S. Patent
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`Jul. 15, 1997
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`Sheet 2 0f 2
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`5,648,711
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`Apple 1014 - Page 3
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`

`
`1
`METHOD AND SWITCHING
`ARRANGEMENT FOR IDENTIFYING THE
`CHARGER OF RECHARGABLE BATTERIES
`OF PORTABLE DEVICES
`
`FIELD OF INVENTION
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`5,648,711
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`devices. Some chargers can even be unsuitable, i.e,, hazard
`ous for the batteries. Consequently, portable devises should
`be able to somehow identify the charger and its properties.
`Similar problems exist for accessory devices generally for
`all types of electronic device, not just battery chargers or
`portable telephones.
`
`The present invention relates to identi?cation apparatus
`and a method therefor.
`In particular, it relates to apparatus and method for
`accessory devices of electronic devices such as portable
`telephones.
`
`BACKGROUND TO INVENTION
`
`There are many types of peripheral devices used with
`electronic devices. A particularly common accessory device
`is a battery charger for portable devices such as portable
`telephones The present invention will now be discussed in
`terms of the state of the art and by way of example, with
`reference to battery chargers.
`There are a number of known methods for charging
`rechargeable batteries for portable devices, such as nickel
`cadmium batteries. Many of these chargers require the
`removal of the batteries from the device to enable recharg
`ing. Removal of the batteries from the device is considered
`a drawback, since the device is out of operation during the
`recharging. However, a number of different chargers have
`been developed which can be attached to a battery powered
`device and the batteries charged in situ in the device. In this
`way, the functionality of the device can be maintained while
`charging the batteries. Even though the functionality of the
`device is maintained, a portable device, such as a mobile
`phone, is unavailable for operation in the manner intended,
`i.e., as a portable device. Since chargers often recharge a
`battery using a fairly low charging current, the battery
`powered device is not available for portable operation for
`extended periods of time, such as eight hours or more dining
`which time the batteries are being recharged.
`Many battery powered devices, such as mobile phones,
`are extremely energy intensive, expending considerable
`amounts of power during the receive functions and more
`particularly during the transmit functions. Because of
`lengthy recharging times, “rapid” chargers have been devel
`oped which can charge batteries fairly rapidly, for example
`In less than an hour as compared with the charging time of
`eight hours for previous battery chargers.
`In order to charge batteries rapidly, numerous problems
`had to be overcome. One of the most serious problems was
`overcharging of the batteries, resulting in turn in the over
`heating of the batteries. Overheating may damage the battery
`case seals, resulting in rupturing of the battery case and In
`extreme instances in explosive rupturing of the battery case.
`In known “rapid” battery chargers most of these problems
`have been solved in one way or another, e.g., by monitoring
`given battery parameters, such as the charging rate of the
`battery, internal battery temperatures or charge state of the
`battery. In some “rapid” chargers, attempts have been made
`to prevent overcharging of the batteries by utilizing timed
`charging of the battery. However, using these known solu
`tions It Is not always possible to prevent overcharging of
`batteries, for instance, when the charger type is not exactly
`a correct one or designed to be used with the battery being
`charged
`Numerous different types of chargers are on the market
`which comprise different charging capacities and charging
`parameters for charging rechargeable batteries of portable
`
`BRIEF SUMMARY OF INVENTION
`
`According to a ?rst aspect of the present invention, there
`is provided identi?cation apparatus for an accessory device,
`comprising coupling means for coupling the accessory
`device to an electronic device and modulation means for
`modulating a signal on the coupling means in accordance
`with identity data for the accessory device.
`According to a second aspect of the present invention,
`there is provided an identi?cation method for an accessory
`device, comprising transmitting an Identity signal from the
`accessory device to an electronic device coupled thereto by
`modulating a signal transmitted therebetween In accordance
`with identity data for the accessory device.
`The present invention provide the advantage that the
`accessory device can indicate to an electronic device to
`which it is connected which peripheral device it is. Thus,
`there is provided a solution to a problem of identifying
`accessory devices.
`In a preferred embodiment the modulation means com
`prises a switch means operable to activate and de-activate
`the coupling means.
`Preferably, the Identi?cation apparatus further comprises
`a bit generator or corresponding charger for generating the
`identity data.
`Suitably, there is provided control means adopted to
`control the modulation means in accordance with the iden
`tity data for superimposing a pulse ratio, pulse length, pulse
`count or the like signal on the on the coupling means.
`Advantageously, there is provided timing means for deter
`mining a time during which the modulation means is
`operable, in particular the timing means comprises a timer
`and a switch operable in accordance with the timer to
`decouple the identity data from the control and/or modula
`tion means.
`Optionally, the switch means comprises a switching tran
`sistor or ?eld effect transistor.
`Identi?cation may be implemented after a certain start-up
`period, before operation, e.g. charging, is started or in the
`initial stage of operation of the accessory device.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`FIG. 1 shows a diagrammatic illustration of the imple
`mentation of apparatus in accordance with the invention,
`FIG. 2 shows a more detailed diagrammatic illustration of
`the apparatus of FIG. 1
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`DETAILED DESCRIPTION OF EMBODIMENTS
`IN ACCORDANCE WITH THE INVENTION
`
`Embodiments in accordance with the Invention are now
`described. by way of example only, and with reference to the
`appended drawings.
`In a device in accordance with the invention a battery
`charger for a transportable device transmits an Identi?cation
`code for the charger via a charging cable, by switching the
`charging voltage on and o? using a certain pulse ratio or
`pulse length or pulse count. Such identi?cation can be
`implemented after a certain start-up time or before starting
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`Apple 1014 - Page 4
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`an actual charging routine It can also be carried out in the
`initial stage of charging after having switched the charging
`on or entered a charging routine.
`FIG. 1 shows an implementation of an embodiment in
`accordance with the Invention. The Identi?cation of the
`charger is formed by using bit generator 1 from which the
`Identi?cation is taken via switching block 2, controlled by
`timing block 3, to control block 4 of a pulse width modu
`lator. A switching transistor or ?eld effect transistor func
`tions as switch 8 and takes a charging voltage containing the
`identi?cation as a modulation imposed thereon, via induc
`tance 6 to the output of the charger. Timing block 3 can also
`operate to control switch 8 to stay on after the pulse
`identi?cation has been transmitted from the charger, The
`main circuit comprises, in a known manner, parallel diode 5
`and parallel capacitor 7 coupled to ground. The charging
`voltage may be the output of a DC/DC converter, the output
`of which is then switched on or oif by switch 8.
`FIG. 2 shows a slightly more detailed diagrammatic
`illustration of the apparatus in accordance with the inven
`tion. The identi?cation of the charger is formed by using
`logic NAND circuit 9 (an AND circuit having an inverting
`output), from where the identi?cation is transmitted to
`control block 4 of the pulse width modulator. The resistances
`shown in FIG. 2 are marked with numbers 10 and 11 and the
`capacitors are marked with numbers 12 and 13. A switching
`transistor or ?eld eifect transistor functions as switch 8 and
`takes the charging voltage containing the identi?cation via
`inductance 6 to the output of the charger. The pulse identi
`?cation is formed until capacitor 12 is charged, switch 8
`being left switched on thereafter.
`In view of the foregoing description it will be evident to
`a person skilled in the art that various modi?cations may be
`made within the scope of the invention. For example, the
`accessory device need not be a battery charger but could be
`some other accessory, and the electronic device need not be
`just a portable telephone. Additionally, the modulation of the
`charging voltage may comprise varying the charging voltage
`as well as switching it on or 011“.
`The scope of the present disclosure includes any novel
`feature or combination of features disclosed therein either
`explicitly or implicitly or any generalization thereof irre
`spective of whether or not it relates to the claimed invention
`or mitigates any or all of the problems addressed by the
`present invention. The applicant hereby gives notice that
`new claims may be formulated to such features during
`prosecution of this application or of any such further appli
`cation derived therefrom
`What I claim is:
`1. Identi?cation apparatus for identifying a charger device
`for rechargeable batteries of portable electronic devices,
`comprising a charger device for providing a charging
`voltage, a low pass ?lter coupling means connected between
`the charger device and for coupling the charging voltage of
`the charger accessory to the electronic device, and modula
`tion means for modulating a signal on the coupling means to
`provide an identi?cation signal in accordance with identity
`data for the charger device.
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`2. Identi?cation apparatus according to claim 1, wherein
`the modulation means includes a switch means operable to
`activate and dc-activate the coupling means.
`3. Identi?cation apparatus according to claim 1, further
`including means connected to the modulation means for
`generating the identify data.
`4. Identi?cation apparatus according to claim 1, wherein
`the modulation means includes control means connected to
`the means for generating the identity data to control the
`modulation means in accordance with the identity data for
`superimposing a pulse ratio, pulse length, or pulse count
`signal on the signal on the coupling means.
`5. Identi?cation apparatus according to claim 1, wherein
`the modulation means includes a control means and wherein
`there is further provided timing means connected to the
`control means of the modulation means for determining a
`time during which the modulation means is operable.
`6. Identi?cation apparatus according to claim 5, wherein
`the ?rming means comprises a timer and a switch operable in
`accordance with the timer to decouple the identity data from
`the control means.
`7. Identi?cation apparatus according to claim 2 wherein
`the switch means comprises a switching transistor or ?eld
`e?’ect transistor.
`8. Identi?cation apparatus according to claim 4 further
`including:
`a logic NAND circuit connected to said control means for
`providing identity data to the control means,
`a ?rst resistance means, and
`a ?rst capacitance means connected to one input of the
`NAND circuit and a second resistance and a second
`capacitance connected to another input of the NAND
`circuit, wherein
`the identity data is formed by using the logic NAND
`circuit, ?'om where the identity data is coupled to the
`control means for a pulse width modulator.
`9. An identi?cation method for a charger device, com
`prising transmitting an identity signal from the charger
`device to an electronic device coupled thereto by modulating
`a signal transmitted between the charger device and the
`electronic device in accordance with identity data for the
`charger device.
`10. A method according to claim 9, wherein the identity
`signal is modulated by switching the identity signal on or
`off.
`11. Identi?cation apparatus according to claim 3 wherein
`said means for generating the identity data is a bit generator.
`12. Identi?cation apparatus according to claim 3 wherein
`said means for generating the identity data is a charger
`device.
`13. Amethod for identifying a charger device providing a
`charging voltage for rechargeable batteries of portable
`devices, characterized in that the charger device transmits an
`identi?cation of the charger device to the portable device via
`a charging cable by switching the charging voltage on and
`off by using given pulse ratio, pulse length or pulse count
`signals.
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`Apple 1014 - Page 5