GB2130029A

GB2130029A - Improvements in battery power supply units

Info

Publication number: GB2130029A
Application number: GB08227689A
Authority: GB
Inventors: Thye Nam Mak
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-09-28
Filing date: 1982-09-28
Publication date: 1984-05-23

Abstract

The supply unit (20) has a set of battery cells 26, 36, to 52, switches 61 to 77 associated with respective cells, positive and negative terminals 21, 22 for connecting the unit to external apparatus and circuitry for connecting together the cells, switches and terminals such that with the switch 61 associated with a first cell (26) in a first position, the first cell 26 is connected across the terminals to enable power to be supplied and the further cell or cells are isolated from the terminals. Position changes of successive switches bring in further cells in series to enable further power to be supplied. The unit may be used to supplement the battery supply of, for example, a radio/cassette player (10, Fig. 1) when the batteries of the player runs down. <IMAGE>

Description

SPECIFICATION Improvements in battery power supply units The invention relates to battery power supply units.

According to the invention, there is provided a battery power supply unit comprising a plurality of battery cells, a switch associated with each cell except one, positive and negative terminals for connecting the unit to external apparatus and means for connecting together the cells, the switch or switches and the time terminals such that with the switch associated with a first cell in a first position, the first cell is connected across the terminals of the unit to enable power to be supplied externally therefrom and the further cell or cells are isolated from the terminals whereby power is not supplied externally therefrom, and with the switch associated with the first cell in a second position, a second cell is connected to the first cell across the terminals to enable power to be supplied externally from both said first and second cells.

The or each switch is preferably a two position switch, and the cells are preferably connected in series to enable power to be supplied.

There is preferably a multiplicity of cells and associated switches.

There is preferably a main switch for controlling output of the unit.

There is preferably a voltmeter for indicating the potential difference across the terminals.

The unit preferably comprises an ammeter for indicating the current flowing through the unit.

Indicator means, for example a lamp, is preferable connected across the terminals, for indicating whether a potential difference exists across the terminals. A switch is preferably included in the indicator means circuit to allow the indicator means to be disconnected or connected as desired.

The unit preferably comprises a housing for the cells, switches, terminals and circuitry.

By way of example, one embodiment of a battery power supply unit according to the invention will now be described with reference the accompanying drawings, in which: Fig. 1 is a diagrammatic illustration of a unit according to the invention supporting a 12 volt power supply of a piece of apparatus; Fig. 2 is a plan view of a unit according to the invention; and Fig. 3 is a circuit diagram of the unit of Fig. 2.

As shown in Fig. 1, a piece of apparatus in this case a radio/cassette player 10 has a 1 2 volt DC power supply from a set of battery cells 11. With continued use of the apparatus 10, the ability of the cells 11 to supply the required power is reduced and the apparatus 10 ceases to function properly.

In order to supplement the power supply 11, a unit generally indicated at 12 can be brought into operation. The unit 12 has a series of cells 13, 14, 1 5 and further cells (not shown) with each of which cells is associated a switch. Switch 1 6 is associated with cell 13, switch 17 is associated with cell 14 and switch 1 8 is associated with cell 1 5. With the switches in the position shown in Fig.

1, the cells 13, 14, and 1 5 are isolated from the power supply 11 so that power is not being supplied from them. However, if switch 1 6 is switched to its second position to close the right hand pair of contacts, cell 1 3 will be connected to the supply 11 to supplement the power supply to the apparatus 1 0. It will be appreciated that a similar position change of switch 1 7 will connect the cell 14 on the power supply and that a similar operation on switch 1 8 will connect the cell 1 5 to the power supply.

Fig. 2 shows an embodiment of a power supply unit according to the invention and Fig. 3 shows a circuit diagram of the unit of Fig. 2.

The unit 20 of Figs. 2 and 3 has positive and negative terminals 21 and 22 respectively to allow the unit to be connected to apparatus or appliances to be powered. The positive terminal 21 is connected by a wire 23 to an ammeter 24 and by a further wire 25 to the positive side of a first cell 26. The negative terminal 22 is connected by a wire 27 to a power switch 28 and then to a wire 29 which can be connected to the negative side cells in the unit 20.

A voltmeter 30 is connected across the terminals 21 and 22 by contact between the wires 27 on the negative side and 25 on the positive side. A voltmeter switch 31 is provided to bring the voltmeter 30 into circuit or take it out of circuit.

A lamp 32 is also connected between the wires 27 and 25 to serve as an indicator of power being supplied by the unit 20. A light switch 33 is provided to cut in or cut out the lamp line.

This embodiment of a unit according to the invention has eighteen cells, the first cell being referred to by reference numeral 26, the second by reference numeral 36, the third by reference numeral 37 and the remaining cells being referred to by reference numerals 38 to 52. The negative side of each cell is connected to a movable contact 60 of an associated two position switch, the eighteen switches being numbered from 61 to 78 although it will be appreciated that the switch 78 associated with the last cell 52 may be omitted because in both positions of the contact 60 the negative side of the cell 52 is connected to the wire 29.

With the movable contacts 60 in the positions shown in Fig. 3, the positive side of the first cell 26 is connected to the positive terminal 21 and the negative side of the first cell 26 is connected to the negative terminal 22 so that the first cell 26 is able to supply power to an external appliance or apparatus if required. The ammeter 24 will indicate the current flowing and the voltmeter 30 will indicate the potential difference across the terminals 21 and 22. The remaining 17 cells are isolated and unable to supply power.

Should it be necessary to supply further power to an appliance or other apparatus, the movable contact 60 of the first switch 61 can be moved to its second position, whereupon the second cell 36 is connected in series with the first cell 26 and both cells 26 and 36 can supply power to an external appliance or apparatus. Similarly, if further power is required, further cells can be successively brought into the circuit to supply power.

As shown in Fig. 2, a housing 80 conveniently a plastics moulding carries the metres, terminals, main switches and lamp in one section and has a series of 18 contact pairs 81 and 82 each for contacting a dry cell battery. The switches 61 to 78 associated with the cells are arranged in rows adjacent the cells.

The advantage of this embodiment of a power supply unit according to the invention is that the power supply to any appartus or appliance using a DC supply can be maintained by successively switching the switches associated with individual cells instead of having to replace at once the power supply of the apparatus or appliance.

Claims

1. A battery power supply unit comprising a plurality of battery cells, a switch associated with each cell except one, positive and negative terminals for connecting the unit to external apparatus and means for connecting the cells, the switch or switches and the terminals such that with the switch associated with a first cell in a first position, the first cell is connected across the terminals of the unit to enable power to be supplied externally therefrom and the further cell or cells are isolated from the terminals whereby power is not supplied externally therefrom, and with the switch associated with the first cell in a second position, a second cell is connected to the first cell across the terminals to enable power to be supplied externally from both said first and second cells.

2. A unit as claimed in claim 1 wherein the or each switch is a two position switch.

3. A unit as claimed in claim 1 or claim 2 wherein the cells are connected in series to enable power to be supplied.

4. A unit as claimed in any preceding claim comprising a housing for the cells, switches, terminals and circuitry.

5. A unit as claimed in any preceding claim comprising a multiplicity of cells and associated switches.

6. A unit as claimed in any preceding claim comprising a main switch for controlling output of the unit.

7. A unit as claimed in any preceding claim comprising a vol meter for indicating the potential difference across the terminals.

8. A unit as claimed in any preceding claim comprising an ammeter for indicating the current flowing through the unit.

9. A unit as claimed in any preceding claim comprising indicator means connected across the terminals for indicating whether a potential difference exists across the terminals.

10. A unit as claimed in claim 9 wherein the indicator means is a lamp.

11. A unit as claimed in claim 9 or claim 10 comprising a switch in the indicator means circuit to allow the indicator means to be disconnected or connected as desired.

12. A battery power supply unit substantially as hereinbefore described with reference to and as shown in the accompanying drawings.