NZ299897A - Construction of electronic circuits using magnetic strips with one conducting surface as the conductive track; for student use - Google Patents

Description

N.Z. PATENT OFFICE DEC 1397 RECEIVED Patents Form No. 5 Patent No: 299897 Dated: 6th December 1996 Patents Act 1953 COMPLETE SPECIFICATION COMPONENTS FOR ELECTRICAL AND ELECTRONIC CIRCUITS I, LESLIE ALLAN BLACK of 153 Waimari Road, Christchurch, NEW ZEALAND, a New Zealand citizen, hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: 1 (to be followed by 1a) 299897 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 1a 9897 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 5 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 10 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 15 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 20 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 L''*) iv. ft f\- a i# it & Jjl 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 5 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 10 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. 3 299897 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 5 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 10 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 20 bricks. The blocks are hsld 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 9989 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 10 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 15 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 20 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 299897 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 7 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, 5 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, 10 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. 15 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 20 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 8 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. -299897

Claims (11)

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. 10 97

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 11 connected to said strips.

10.A component substantially as herein before described with reference to and as shown in the accompanying drawings.

11.A kit substantially as herein before described with reference to and as shown in the accompanying drawings. LESLIE ALLAN BLACK. by his authorised agents, P.L. BERRY & ASSOCIATES. END OF CLAIMS 12