GB2309360A - Portable terminal power supply with primary and secondary cells - Google Patents

Portable terminal power supply with primary and secondary cells Download PDF

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Publication number
GB2309360A
GB2309360A GB9701298A GB9701298A GB2309360A GB 2309360 A GB2309360 A GB 2309360A GB 9701298 A GB9701298 A GB 9701298A GB 9701298 A GB9701298 A GB 9701298A GB 2309360 A GB2309360 A GB 2309360A
Authority
GB
United Kingdom
Prior art keywords
cell
transmission
circuit
power supply
portable terminal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9701298A
Other versions
GB9701298D0 (en
Inventor
Mamoru Yataka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP8007987A priority Critical patent/JPH09200967A/en
Application filed by NEC Corp filed Critical NEC Corp
Publication of GB9701298D0 publication Critical patent/GB9701298D0/en
Publication of GB2309360A publication Critical patent/GB2309360A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0209Power saving arrangements in terminal devices
    • H04W52/0261Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0296Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level switching to a backup power supply
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/3827Portable transceivers
    • H04B1/3883Arrangements for mounting batteries or battery chargers
    • Y02D70/40

Description

POWER SUPPLY CIRCUIT DEVICE FOR PORTABLE TERMINAL The present invention relates to a power supply circuit device used in a portable terminal such as a bidirectional pager or PDA (Personal Digital Assistants) and, more particularly, to a power supply circuit for a portable terminal having a radio transmission unit which consumes a large power in transmission and uses a cell as a power supply.
A conventional power supply circuit device for a portable terminal of this type uses, as a power supply, a disposable primary cell such as a manganese dry cell or an alkali dry cell, which is relatively easily accessible, or a secondary cell such as a lithium-ion cell or a nickel-cadmium cell which can be charged and repeatedly used.
When a primary cell such as a manganese dry cell or an alkali dry cell is used, the voltage drop of the cell becomes large during the operation of the transmission unit which requires a large current because of the relatively large internal resistance of the primary cell. Accordingly, the number of dry cells must be increased to increase the cell capacity as compared with a required one so that there is no problem when the voltage drop of the dry cells occurs. As a result, this increases the volume of the cell storage unit to result in a bulky device. Since size reduction is required for portable terminals, an increase in the size of the device poses a serious problem because it does not meet the demand of the users.
On the other hand, when a secondary cell such as a lithium-ion cell or a nickel-cadmium cell is used, a charger is necessary, and the charge operation is inconvenient and requires a bulky external charger.
The present invention has been made in consideration of the above situation, and has as an object of at least its preferred embodiment to provide a compact power supply circuit for a portable terminal, which can prevent the voltage drop of a cell in transmission without increasing the number of primary cells, and which also avoids an inconvenient recharging operation.
Accordingly, a first aspect of the present invention provides a power supply circuit for a portable terminal, comprising: means configured for accommodating a secondary cell for supplying power to a radio transmission circuit of the terminal during transmission therefrom; and means configured for accommodating a primary cell for charging said secondary cell following the supply of power to said transmission circuit.
According to a second aspect of the present invention, there is provided a power supply for a portable terminal, comprising: a low impedance output secondary cell arranged for supplying a power to a radio transmission circuit; and a primary cell arranged for charging said secondary cell to replace power consumed in transmission.
In a third aspect the invention provides a power supply circuit device for a portable terminal, comprising: a primary cell for supplying power to operative circuits of the terminal except for a transmission circuit thereof; a secondary cell for supplying power exclusively to said transmission circuit; a step-up circuit for boosting voltage of said primary cell; means controllable to apply an output voltage from said step-up circuit to said secondary cell for a predetermined period of time to charge said secondary cell immediately after completion of transmission by said transmission circuit.
According to a fourth aspect of the present invention, there is provided a power supply circuit device for a portable terminal, comprising a primary cell for supplying a power to operation units except a transmission unit of the portable terminal, a secondary cell for exclusively supplying a power to the transmission unit, a step-up circuit for boosting a voltage of the primary cell, switch means controlled to apply an output voltage from the step-up circuit to the secondary cell to charge the secondary cell immediately after completion of transmission by the transmission unit, and a control circuit for outputting a charge control signal to the switch means to turn on a switch of the switch means for a predetermined charge time.
The invention also provides a portable radio transmission circuit with a power supply circuit as set forth above.
According to a preferred embodiment of the present invention, in the power supply circuit device of the portable terminal, the power from the secondary cell having a low internal resistance is supplied to the transmission unit which instantaneously requires a large current in transmission unit, and immediately after completion of transmission, the secondary cell which has consumed the power for transmission is charged with the output voltage from the primary cell serving as the power supply for the operation units except the transmission unit. With this arrangement, the capacity in a steady state except the transmission mode suffices for the primary cell, so that the entire device can be made compact without increasing the number of dry cells as primary cells. In addition, the dry cells as primary cells can be easily exchanged. Furthermore, the inconvenience of the charge Operation can be uced in nparision to a case in which only a secondary ceU. is used as the power supply.
The above and many other advantages and feaaes of the present invention will become manifest to those versed in the art upon making reference to the following detailed description and accompanying drawings in which preferred embodiments incorporating the principles of the present invention are shown by way of illustrative example.
Fig. 1 is a block diagram showing the overall arrangement of an embodiment of the present invention; and Fig. 2 is a timing chart for explaining the operation of the embodiment shown in Fig. 1.
An embodiment of the present invention will be described below with reference to the accompanying drawings.
Fig. 1 is a block diagram showing the overall arrangement of the embodiment of the present invention. Fig. 2 is a timing chart for explaining the operation of the embodiment shown in Fig. 1.
Referring to Fig. 1, reference numeral 1 denotes a primary cell such as a manganese dry cell or an alkali dry cell which is connected to a step-up circuits 2. An output from the primary cell 1 is boosted to a voltage slightly higher than an output voltage from a secondary cell 4 such as a lithium-ion cell or a nickel-cadmium cell. The voltage boosted by the step-up circuit is applied to a switch unit 3 and a control unit 5.
The control unit 5 outputs a transmission control signal S1 for controlling transmission by a transmission unit 6 and a charge control signal S2 for turning on the ON/OFF switch of the switch unit 3 immediately after completion of transmission.
The switch unit 3 holds the ON/OFF switch in an ON state for a predetermined period of time in accordance with the charge control signal 52 and applies an output voltage from the step-up circuit 2 to the secondary cell 4 to charge the secondary cell 4.
The primary cell is used as the power supply for the operation units except the transmission unit of the portable terminal in the steady state while the secondary cell 4 is exclusively used as the power supply for the transmission unit.
The operation associated with the embodiment shown in Fig. 1 will be described below.
When transmission by the transmission unit 6 is to be performed, the transmission control signal S1 is output from the control unit 5 to operate the transmzssion unit. At this time, the charge control signal S2 is not output from the control unit, and the ON/OFF switch of the switch unit 3 its in an OFF state. Since the switch unit 3 is in the OFF state, the transmission unit 6 is disconnected from the primary cell 1, so that the secondary cell 4 exclusively serves as the power supply for the transmission unit 6.
That is, the power necessary for transmission is exclusively supplied from the secondary cell 4.
Upon completion of transmission, the transmission control signal S1 is not output from the control unit 5.
Instead, the charge control signal S2 is immediately output from the control unit 5. With this operation, the ON/OFF switch of the switch unit 3 is held in an ON state for a predetermined period of time. Consequently, the output voltage from the primary cell 1, which is boosted by the step-up circuit 2, is applied to the secondary cell 4 to charge the secondary cell 4.
The charge time of the secondary cell 4 by the primary cell 1 will be described below.
The electric energy of the secondary cell 4, which has been consumed by transmission, is calculated by transmission current x transmission time. As the transmission current, generally, a predetermined value is set in units of types of portable terminals. The transmission time for one packet in packet transmission is as short as 6 msec.
Referring to Figs. 1 and 2, a charge time t2 in charging the secondary cell 4 for the electric energy consumed in transmission is calculated. Assuming that the transmission current is 1 A, a transmission time tl is 10 msec, and the charge current by the primary cell 1 is 100 mA, 1 A x 10 msec = 100 mA x t2 Therefore, the calculated charge time t2 is 100 msec.
However, assuming that the charge efficiency of the secondary cell 4 is 70%, the actual charge time t2 is 140 msec.
The charge time of the secondary cell 4 equals the ON-state holding time of the switch unit 3 in accordance with the charge control signal S2.
As described above, the charge time t2 of the secondary cell 4, i.e., the ON-state holding time of the switch unit 3 is set depending on the transmission time tl. Therefore, when a plurality of charge time data are stored in advance in a device such as a timer and/or a memory (neither are shown) arranged in the control unit 5 in correspondence with a plurality of transmission time patterns, the charge time t2 can be easily set.
Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other disclosed and/or illustrated features.
The text of the abstract filed herewith is repeated here as part of the specification.
A power supply circuit device for a portable terminal includes a primary cell for supplying a power to operation units except a transmission unit of the portable terminal, a secondary cell for exclusively supplying a power to the transmission unit, a step-up circuit for boosting a voltage of the primary cell, a switch unit controlled to apply an output voltage from the step-up circuit to the secondary cell to charge the secondary cell immediately after completion of transmission by the transmission unit, and a control for outputting a charge control signal to the switch unit to turn on a switch of the switch unit for a predetermined charge time.

Claims (8)

1. A power supply circuit for a portable terminal, comprising: means configured for accommodating a secondary cell for supplying power to a radio transmission circuit of the terminal during transmission therefrom; and means configured for accommodating a primary cell for charging said secondary cell following the supply of power to said transmission circuit.
2. A power supply for a portable terminal, comprising: a low impedance output secondary cell arranged for supplying power to a radio transmission circuit; and a primary cell arranged for charging said secondary cell to replace power consumed in transmission.
3. A circuit or power supply according to Claim 1 or Claim 2, further comprising: switch means controllable to apply a voltage output from said primary cell to said secondary cell to charge said secondary cell following completion of the transmission by said transmission circuit; and control means for outputting a control signal to said switch means to apply said voltage for a predetermined period of time.
4. A circuit or power supply according to any preceding claim, further comprising: means for boosting the output voltage of said primary cell.
5. A power supply circuit device for a portable terminal, comprising: a primary cell for supplying power to operative circuits of the terminal except for a transmission circuit thereof; a secondary cell for supplying power exclusively to said transmission circuit; a step-up circuit for boosting voltage of said primary cell; means controllable to apply an output voltage from said step-up circuit to said secondary cell for a predetermined period of time to charge said secondary cell immediately after completion of transmission by said transmission circuit.
6. A device according to Claim 5, wherein the said time period is set depending on the duration of transmission by said transmission circuit.
7. A power supply circuit substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.
8. A portable radio transmission terminal comprising a power supply circuit or a power supply according to any preceding claim.
GB9701298A 1996-01-22 1997-01-22 Portable terminal power supply with primary and secondary cells Withdrawn GB2309360A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8007987A JPH09200967A (en) 1996-01-22 1996-01-22 Power circuit for portable remote terminal

Publications (2)

Publication Number Publication Date
GB9701298D0 GB9701298D0 (en) 1997-03-12
GB2309360A true GB2309360A (en) 1997-07-23

Family

ID=11680783

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9701298A Withdrawn GB2309360A (en) 1996-01-22 1997-01-22 Portable terminal power supply with primary and secondary cells

Country Status (4)

Country Link
JP (1) JPH09200967A (en)
AU (1) AU1227397A (en)
GB (1) GB2309360A (en)
TW (1) TW312057B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2332824A (en) * 1997-12-29 1999-06-30 Samsung Electronics Co Ltd Power supply device for mobile communication terminal
EP1742373A1 (en) * 2005-07-05 2007-01-10 Somfy SAS Autonomous domestic sensor-transmitter and its method of operation
WO2010127725A1 (en) * 2009-05-07 2010-11-11 Telefonaktiebolaget Lm Ericsson (Publ) Managing a power consumption of a mobile communication device
EP2899833A4 (en) * 2012-09-18 2015-10-14 Meisei Electric Co Ltd Radiosonde power source device and radiosonde

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013044221A2 (en) * 2011-09-23 2013-03-28 Honda Motor Co., Ltd Selective current reduction enabled with electrically deactivated key fob

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0620655A2 (en) * 1993-04-16 1994-10-19 Nec Corporation Selective-calling radio receiver
EP0641089A2 (en) * 1993-08-31 1995-03-01 Nec Corporation Portable radio apparatus having batteries for supplying a plurality of voltages
US5438696A (en) * 1993-07-26 1995-08-01 Motorola, Inc. Method and apparatus for controlling radio frequency interference generated by a voltage multiplier
EP0688082A1 (en) * 1994-06-17 1995-12-20 Kabushiki Kaisha Mimasu Kinzoku Seisakusho Portable communication apparatus preventing trouble when battery wears

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01144327A (en) * 1987-11-27 1989-06-06 Matsushita Electric Ind Co Ltd Charging of electronic machinery
JPH0678465A (en) * 1991-04-24 1994-03-18 Fujitsu Ltd Combination battery
JPH07297785A (en) * 1994-04-27 1995-11-10 Casio Comput Co Ltd Electronic apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0620655A2 (en) * 1993-04-16 1994-10-19 Nec Corporation Selective-calling radio receiver
US5438696A (en) * 1993-07-26 1995-08-01 Motorola, Inc. Method and apparatus for controlling radio frequency interference generated by a voltage multiplier
EP0641089A2 (en) * 1993-08-31 1995-03-01 Nec Corporation Portable radio apparatus having batteries for supplying a plurality of voltages
EP0688082A1 (en) * 1994-06-17 1995-12-20 Kabushiki Kaisha Mimasu Kinzoku Seisakusho Portable communication apparatus preventing trouble when battery wears

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2332824A (en) * 1997-12-29 1999-06-30 Samsung Electronics Co Ltd Power supply device for mobile communication terminal
GB2332824B (en) * 1997-12-29 2000-03-08 Samsung Electronics Co Ltd Power supply device for mobile communication terminal
EP1742373A1 (en) * 2005-07-05 2007-01-10 Somfy SAS Autonomous domestic sensor-transmitter and its method of operation
FR2888425A1 (en) * 2005-07-05 2007-01-12 Somfy Sas AUTONOMOUS DOMOTIC TRANSMITTER SENSOR AND METHOD FOR OPERATING SAME
WO2010127725A1 (en) * 2009-05-07 2010-11-11 Telefonaktiebolaget Lm Ericsson (Publ) Managing a power consumption of a mobile communication device
RU2531356C2 (en) * 2009-05-07 2014-10-20 Телефонактиеболагет Лм Эрикссон (Пабл) Control of power consumption of mobile communication device
US10206177B2 (en) 2009-05-07 2019-02-12 Telefonaktiebolaget Lm Ericsson (Publ) Managing a power consumption of a mobile communication device
EP2899833A4 (en) * 2012-09-18 2015-10-14 Meisei Electric Co Ltd Radiosonde power source device and radiosonde

Also Published As

Publication number Publication date
TW312057B (en) 1997-08-01
GB9701298D0 (en) 1997-03-12
JPH09200967A (en) 1997-07-31
AU1227397A (en) 1997-07-31

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)