WO1998025253A1

WO1998025253A1 - Components for electrical and electronic circuits

Info

Publication number: WO1998025253A1
Application number: PCT/NZ1997/000161
Authority: WO
Inventors: Leslie Allan Black; John Dunbier
Original assignee: Chapman, Dennis, Alan
Priority date: 1996-12-06
Filing date: 1997-12-04
Publication date: 1998-06-11
Also published as: NZ299897A; AU5140898A

Abstract

A kit of components for use in constructing electrical and electronic circuits for hobby or instructional purposes is characterized by including a component (2) comprising electrically insulating permanently magnetic material (2a) having an electrically conductive layer (2b) supported thereon. The component (2) serves to locate and hold joining strips (3) and other electronic components (4) in place by magnetic attraction while completing the electrical circuit via the conductive layer (2b).

Description

TITLE: COMPONENTS FOR ELECTRICAL AND ELECTRONIC CIRCUITS

Technical Field

The present invention relates to a component for electrical and

electronic circuits, and in particular to a component suitable for use in hobby

kits and instructional kits for educational use, for making up electrical and

electronic circuits.

Background Art

At present, electrical and electronic construction kits contain a variety

of electrical/electronic components which have to be assembled into circuits by

connecting the components together with wire, using soldered connections or

using screw threaded connections of known type. Construction kits requiring

soldering are well known. However, soldering is a relatively skilled task, and

requires the use of a hot soldering iron; this is difficult and/or dangerous for

many children to use, and is a particular drawback in a classroom situation

where hot soldering irons frequently cause minor burns and other accidents.

Even though it is possible to use screw threaded or similar types of

connections, these are fiddly to make. Thus, for a child to assemble an

electrical or electronic circuit that works can be a long and tedious job often

involving considerable manual skill. This slows down electrical and electronic

experimental work in the classroom, simply because building each

demonstration circuit takes a disproportionately long time.

To overcome at least some of these drawbacks, a number of such

educational kits have employed magnets to secure electrical/electronic components in various ways, as disclosed in the following patents;

EP 526090 discloses an electronic teaching kit in which the electronic

components are mounted on individual tiles. Each tile has a layer of plastic

magnetic material which enables each piece to be secured by magnetic

attraction to a board with an electrically insulated surface.

The components on the tiles are electrically connected to each other by means

of coiled extension springs mounted on each tile and connecting wires. The

springs are bent over to open the coils and a connecting wire is introduced

between two coils. Releasing the spring secures the wire. This design

overcomes the problem of soldering connections between wires and

components, but the connections between the wires and the components

nevertheless require a reasonable degree of manual dexterity:- insulation has

to be stripped from the ends of the wires, and the striped ends of the wires

must be carefully inserted into the coils, or a good connection will not be

achieved. Further, the coils are relatively easily damaged in use:- if they are

stretched or over bent, they will not contact the wire firmly enough to make a

good electrical connection.

U.S. 384573 also uses magnets to attach electrical components to a

electrically insulated base plate. The components can be either mounted on a

tile (in a similar fashion to EP 526090) or direct to small magnets attached to

each component 'leg'.

The tile uses electrically conductive magnetic blocks to attract both the

electrical components (via small metal pieces attached to the component legs/wires) and the base plate. Several embodiments are disclosed including

mounting the electrical components directly (via the magnets) onto the base

plate without using the tiles.

However, common to all embodiments is the means of interconnecting

different components by the use of 'jumpers' (lengths of flexible wire with rod or

disc shaped end pieces) inserted into appropriately shaped 'connectors'

attached to the component/tile.

In addition to the cost of producing such a connector system, an

additional drawback is the difficulty that would be experienced by children in

manipulating the rather intricate connectors.

U.S. 3510963 also uses magnets to mount electrical components onto

a board (a classroom chalk-board in the preferred embodiment) in a similar

fashion to the above prior art with the following difference in implementation

and operation;

• Multiple circuit components are wired together on a common

'circuit panel' magnetically attached to a board, though mention is made of

mounting a single component on a circuit panel.

• The majority of the component wiring is placed underneath the

circuit panels,

• Separate circuit panels are connected both to each other and to

the power distribution system with flexible ('stretchable') conductive leads via

pins/u-shaped connector interfaces. Although useful for demonstrating/teaching to a large audience, this

system is not readily adaptable for use by individuals or small groups. The

cost of manufacturing the required power distribution system and connector

means is a further disadvantage for teaching system intended for widespread

distribution amongst schools or similar.

U.S. 3205407 discloses a series of 'contact members' (securable to a

base plate) consisting of an electrically insulating material with a central cavity

and an electrical contact unit located within the cavity. Pins or prongs/pegs

can be inserted into the cavities to provide a secure electrical contact, said pins

being attached either to the ends of connecting leads/wires or to boards

mounting an electrical component. While one embodiment makes use of

magnets as a means of securing the contact members to the base plate, all the

interconnections between components is via the friction fit of a pin/peg inside

the cavities within contact members.

The connecting system requires the production of specialised

components (pegs, contact members etc) specific to this application, which

would be very expensive to manufacture.

U.S. Patent No. 3447249 employs a system of assembling

electric/electronic circuits from identically sized (or multiple thereof) blocks or

bricks. The blocks are held together by magnets on at least two faces with the

electrical component for each block contained internally. The external

electrical connections are such that the magnetic bond between two bricks

produces a suitable electrical contact protected from outside interference/contact. The upper surface of the block is printed with the

electrical symbols and connections corresponding to the actual internal layout

and enabling a circuit to be thus assembled by connecting together the blocks

to form the pictorial representation of the required circuit.

Whilst this system has several attractive features, the cost of

manufacturing blocks with such complicated internal structure would lead to a

prohibitive retail price for schools/colleges.

Disclosures of Invention

It is therefore an object of the present invention to provide a

component for constructing electrical and electronic circuits which enables

those circuits to be built up rapidly and accurately, even by a person lacking in

manual skill.

The present invention provides a component for an electrical or

electronic circuit comprising a strip of electrically-insulating permanently

magnetic material, one surface of which supports an electrically conductive

material.

The electrically conductive material may be a coating of an electrically

conductive material (for example copper or aluminium) or may be a strip of

copper or other conductive material secured along one surface of the

permanently magnetic base material.

The invention further provides the combination of the above described

component, a magnetic base plate, joining strips of electrically conductive

magnetic material, and a selection of electrical or electronic components mounted upon magnetic or permanently magnetic bases, each said electrical

or electronic component being provided with at least two electrical contacts.

As used herein, the term "permanently magnetic material" means a

material which has a permanent magnetic field, and the term "magnetic

material" means a material such as iron which becomes magnetised when in a

magnetic field.

Brief Description of Drawings

By way of example only, a preferred embodiment of the present

invention is described in detail with reference to the accompanying drawings, in

which;

Fig. 1 shows a diagrammatic sectional view through part of an

electronic circuit constructed with the components of the present invention.

Fig. 2 shows a perspective view of a second preferred embodiment of

an electrical/electronic component and mounting board.

Fig. 3 shows an exploded plan view of the underside of the mounting

board shown in fig. 2.

Fig. 4 shows a plan view of the underside of a third preferred

embodiment of a mounting board;

Fig. 5 shows a perspective view of a fourth preferred embodiment of

an electronic component and mounting board.

Best Mode(s) for carrying out the Invention

Referring to the drawings, part of an electronic circuit is formed by a

series of spaced permanently magnetic strips 2 connected together either by joining strips 3 or by electronic components 4.

Each magnetic strip 2 comprises a base 2a of electrically insulating

permanently magnetic material of known type and an electrically conductive

layer 2b covering the upper surface of each strip 2. The layer 2b may be

formed as a coating (e.g. sprayed on) or as a strip but preferably is an

adhesive strip of tinned copper or copper. The permanently magnetic strips 2

may be made in any desired length, and preferably are made in a range of

lengths and/or shapes, so that they can conveniently assembled to form a wide

range of circuits, as required.

A circuit is laid out on a base plate 5 of magnetic material (e.g. a steel

sheet) simply by placing the magnetic strips 2 on the base plate in the desired

configuration to construct the circuit. For teaching purposes, or as part of an

instructional kit, a paper sheet 6 showing the desired circuit in printed form may

be laid on top of the base plate 5, to indicate where to put the magnetic strips

2.

If it is necessary to electrically join two adjacent magnetic strips 2, a

joining strip 3, in the form of a strip of magnetic material such as a magnetic

steel is used to bridge across between the conductive upper surfaces of

adjacent strips 2. The strip 3 is held securely in place by magnetic attraction to

the magnetic strips 2; the magnetic attraction ensures electrical connection.

The strips 3 may be flat, or arched for easier handling.

The electrical and electronic components 4 are mounted on an

insulating base 7 and permanently connected by wires (not shown) to steel rivets 8 which project through the insulating base 7 to contact the connection

wires and the surface 2b of the adjacent strips. Thus, an electronic component

may be connected between two adjacent strips 2 simply by placing the

component on its insulating base 7 as a bridge between the adjacent strips,

with each rivet 8 contacting the electrically conductive layer 2b of one of said

strips.

As shown in fig. 2 and 3, in one embodiment, the legs 9 of the

component 4 pass through holes in the insulating base, emerging through

apertures on the lower surface 10 encompassed by an etched copper track 11 ,

12. The etched tracks 11 , 12 (of the type commonly employed in PCB

manufacture) connect each component leg to the attachment point for a rivet 8.

The whole component board is flow soldered by conventional means so that

the solder adheres only to the exposed copper track. The rivets 8 are added

after the soldering, to form electrical connections with the copper track.

Alternatively, (as shown in fig 4) the insulating base 7 of each

electronic component may be surfaced on its underside with strips 13 of

conductive material which are connected through to the component by any

suitable means.

Large electrical/electronic components 14 or those requiring several

electrical contacts such as transformers or relays may be mounted on an

insulating base 7 with its wires soldered to a plurality of electrical contact areas

15 located on the upper surface (as shown in fig. 5). Permanently magnetic

material 2 is attached to the underside of the board 7 to enable the board to be attached directly to the base 5. Electrical connections to components mounted

in this way be made by joining strips 3 contacting a contact area 15 and held in

contact by the magnetic attraction between the strip 3 and the permanently

magnetic material 2 on the base of the component.

Where the joining of the components 4 would require an unduly long

strip 3, or if a connection is required to 'bridge' other connections/components,

a flexible lead may be employed with a rivet 8 fixed to each end.

It will be appreciated that the above described components enable an

electronic or electrical circuit to be assembled and disassembled rapidly,

accurately and safely, and thus greatly reduce the assembly and disassembly

time needed for such circuits, without compromising the efficiency of the circuit

once assembled.

Claims

CLAIMS:

1. A component for an electrical or electronic circuit comprising a strip of

electrically-insulating permanently magnetic material, one surface of which

supports an electrically conductive material.

2. A component as claimed in claim 1 wherein the electrically conductive

material is a coating of an electrically conductive material.

3. A component as claimed in claim 1 wherein the electrically conductive

material is a strip of copper or other conductive material secured along one

surface of the permanently magnetic base material.

4. A kit including two or more components as claimed in any one of claims 1-3

and one or more joining strips of electrically conductive material.

5. A kit comprising a combination of a plurality of the component as claimed in

any one of claims 1-3, a magnetic base plate, joining strips of electrically

conductive magnetic material, and a selection of electrical or electronic

components each mounted upon an electrically insulated base and including

magnetic or permanently magnetic elements, each said electrical or

electronic component being provided with at least two electrical contacts.

6. A kit as claimed in claim 5 wherein at least some of said electrical/electronic

components comprise a component connected to electrically conductive

rivets projecting through the electrically insulated base to form said electrical

contacts.

7. A kit as claimed in claim 5 or claim 6 wherein at least some of said

electrical/electronic components comprise components mounted on an

upper surface of the electrically insulated base with component connecting

wires passing through apertures in said insulated base and connected via

flow soldered etched tracks on the lower surface of the electrically insulated

base to conductive rivets which form said electrical contacts and also

provide said magnetic elements.

8. A kit as claimed in any one of claims 5-7 wherein for a least some of the

electrical/electronic components, the said electrical contacts are formed on

the upper surface of the electrically insulated base and permanently

magnetic material is provided on a lower surface of the electrically insulated

base.

9. A kit as claimed in any one of claims 5-8 wherein for a least some of the

electrical/electronic components, the said electrical contacts are formed as

strips of conductive material on the underside of the electrically insulated base through which the electrical/electronic component is electrically

connected to said strips.