WO2012143873A1

WO2012143873A1 - Electrical device

Info

Publication number: WO2012143873A1
Application number: PCT/IB2012/051957
Authority: WO
Inventors: Mauro Possanza
Original assignee: Indesit Company S.P.A.
Priority date: 2011-04-19
Filing date: 2012-04-19
Publication date: 2012-10-26
Also published as: ITRN20110030A1

Abstract

An electrical device comprising: - an outer casing (2); - a plurality of electrical connection terminals accessible from outside the casing (2), comprising in turn of at least one first, second and third terminal (31, 32, 33); - at least one electrical jumper (41), positioned inside the casing (2), which electrically connects the first and second terminal (31, 32); said first electrical jumper (41), at 20°C, having an electrical resistance between 0 and 0.05 ohm; inside the casing (2) said third terminal (33) being electrically insulated from the first and the second terminals (32, 32).

Description

Description Electrical device Technical Field

This invention relates to an electrical device and a method for constructing an electronic board.

Background Art

During the design of electronic equipment, one sometimes becomes aware that it would be possible to use the electrical/electronic arrangement of a board used for a different function by simply modifying some components. This normally requires a complete revision of the layout of the electronic board in order to correctly position all the electronic components. This is necessary because each component has its own particular dimensions standardised by specific regulations. This operation is not without problems, the first being the time physically necessary to redesign and construct the correct layout of the board.

Disclosure of the Invention

In this context, the technical purpose which forms the basis of this invention is to propose an electrical device and a method for constructing an electronic board that overcome the above mentioned drawbacks of the prior art.

More specifically, the aim of this invention is to provide an electrical device capable of making it possible to replace a single component intended to be part of an electronic board by modifying the electrical/electronic arrangement, but without radically changing the layout.

The technical purpose indicated and the aims specified are substantially achieved by a method comprising the technical features described in one or more of the appended claims.

Brief Description of the Drawings

Further features and advantages of the invention are more apparent in the non-limiting description which follows of a preferred embodiment of an electrical device illustrated in the accompanying drawings, in which:

- figures 1 and 2 illustrate right-angled schematic views of a device in accordance with this invention;

- figure 3 illustrates another embodiment of a device in accordance with this invention;

- figures 4 and 5 illustrate the circuit diagram of an electronic board before and after the implementation of an adaptation method in accordance with this invention.

In particular, this invention is based on the idea of being able to use (replacing just one component) an electronic board previously used to control a LED (fig. 4) in order to control a sensor of a household appliance, typically a turbidity sensor (fig. 5) .

Detailed Description of the Preferred Embodiments of the Invention

This invention relates to an electrical device 1. The device 1 comprises:

- an outer casing 2;

- a plurality of electrical connection terminals which protrude externally from the casing 2, said plurality of electrical connection terminals comprising at least one first, second and third terminal 31, 32, 33. Said plurality of terminals are made from electrical conduction material and protrude externally from inside the casing 2. Said plurality of terminals extend in cantilever fashion from the casing 2.

The device 1 comprises at least a first electrical jumper 41 which electrically connects the first and second terminal 31,

32. The first jumper 41 is positioned inside the casing 2.

Conveniently, the casing 2 is made of electrically insulating material (typically of plastic material). Metal fins could be present (solution not illustrated) on the plastic casing (to improve cooling) . The first electrical jumper 41, at 20°C, has an electrical resistance between 0 and 0.05 ohm, preferably between 0 and 0.03 ohm. The first electrical jumper 41 can be made with materials and technologies known for the production of electrical resistances in chip form.

Inside the casing 2, the third terminal 33 is electrically insulated from the first and second terminals 31, 32. There is therefore no electrical pathway inside the casing 2 that electrically connects the first and second terminal 31, 32. This electrical insulation is provided by the casing 2. Conveniently, the first jumper 41 is countersunk in the casing 2. The first jumper 41 consists of an electrical pathway that connects the first and second terminal 31, 32. Said plurality of terminals of the device 1 comprises at least one additional terminal (solution not illustrated). In a first embodiment, said additional terminal, inside the casing 2, is electrically insulated from all the other terminals of said plurality of terminals. In particular, there is therefore no electrical pathway inside the casing 2 that connects the additional terminal to the first and to the second terminal 31, 32.

In an alternative solution, said additional terminal is connected to at least one of the remaining terminals, except for the third one 33, by means of an additional electrical jumper having a resistance between 0 and 0.05 ohm at 20°C (preferably between 0 and 0.03 ohm at 20°C) . This additional electrical jumper is also inside the casing 2.

The casing 2 comprises an outer surface 20 in turn comprising:

- first and second opposite bases 21, 22;

- a side surface 23 developing between the first and second base 21, 22; the first, the second and the third terminals 31, 32, 33 extending externally from the casing 2 starting from said side surface 23.

Conveniently, the first and second base 21, 22 are substantially quadrilateral and the side surface 23 comprises a first, a second, a third and a fourth face 24, 25, 26, 27. The casing 2 is substantially a prismatic body.

In the example illustrated in figure 2, at least two terminals among the first, the second and the third terminals 31, 32, 33 are on the first face 24 and the remaining terminal is on the third face 26. In the example illustrated in figure 2, the second 32 and the third terminal 33 are on the first face 24. The third face 26 is opposite the first face 24. In an alternative embodiment (see figure 3), the first, the second and the third terminal 31, 32, 33 are on the first base 21.

Conveniently, the first connection terminal 31 does not intersect the imaginary extension of the second connection terminal 32. The extension is at right angles to the plane tangent to the casing 2 in the zone where the second terminal 32 protrudes externally from the casing 2. The positioning of the various terminals with respect to the casing 2 does in fact follow the standardised and precoded dimensions of certain already existing electronic components.

Conveniently, the electrical device 1 has one of the following standardised dimensions:

-SOT-89, SOT-23, SOT-323, SOT-416, SOT-63, SOT-723, SOT-883

(with three terminals);

-SOT-223 (four terminals);

-DPAK (three or five terminals);

-D2PAK (three, five, six, seven, eight, or nine terminals)

-D3PAK;

-SOT-23-5, SOT-23-6, SOT-23-8, SOT-353, SOT-363, SOT-563, SOT- 665, SOT-666, SOT-886, SOT-891, SOT-953, SOT-963 (five or six terminals ) ;

Alternatively, the device 1 presents the dimensions of an electronic component belonging to one of the following standardised dimensional families: DIP, SOIC, SOJ, PLCC (with eight or nine terminals) .

The dimensions indicated above are well known and unambiguously identified in the technical sector. They correspond to standard dimensions of well known electronic components.

Advantageously, the electrical device 1 comprises visual means of recognition. For example, the casing 2 could be coloured red to distinguish it from other electrical/electronic components with a different colour casing.

The subject of this invention is also a method for the assembly of an electronic board comprising the step of connecting it to an electrical device 1 having one or more of the technical features described above. The step of connecting the board to an electrical device 1 comprises the step of electrically and physically connecting the first terminal 31 of said electrical device 1 to a first contact 71 on the board, the second terminal

32 of said electrical device 1 to a second contact 72 on the board 7, and the third terminal 33 of said electrical device 1 to a third contact 73 on the board 7.

Conveniently, all the electrical terminals of the electrical device 1 are connected to corresponding contacts on the board 7.

A subject of this invention is a method for construction of a second electronic board using at least one printed circuit developed for a first electronic board. The first electronic board can be used for a first application and foresees the use of :

- said printed circuit provided with predetermined electrical tracks ;

- a first electronic component 6 connected to said printed circuit in a first zone of said printed circuit and physically connected to a first, a second and a third contact 71, 72, 73 of the printed circuit (in particular of the electrical tracks). The method comprises the step of assembling a second electronic board which can be used for a second application different from the first application; the step of assembling said second board comprising the steps of procuring at least the printed circuit of the first board and connecting it to an electrical device 1 having one or more of the technical features described above (instead of said electronic component 6) . The step of connecting the electrical device 1 to said printed circuit comprises the step of electrically and physically connecting the third terminal 33 of said electrical device 1 to the third contact 73 of the printed circuit, the second terminal 32 of said electrical device 1 to the second contact 72 of the printed circuit, and the first terminal 31 of said electrical device 1 to the first contact 71 of the printed circuit.

Advantageously, the method for construction of the second electronic board comprises the design of said first electronic board (in this case this step is carried out before assembly of the second electronic board) .

Conveniently, the electronic component 6 is a transistor (for example bjt or mosfet) or a triac and comprises:

- an input of the electrical current;

- an output of the electrical current;

- a control port for the transfer of current from the input to the output;

In said first board the first and second contacts 71, 72 of the printed circuit are connected one to said input and one to said output .

A bjt transistor typically comprises three terminals, conventionally called base, collector and transmitter. In this case, the collector and transmitter are represented one by said input and one by said output. In the case of a mosfet, the collector is usually called a drain, the transmitter a source and the base a gate.

In the case of a triac, said input and said output are typically represented one by the terminal MT1 of the triac and the other by the terminal MT2 of the triac.

The electronic component 6 could also be an integrated circuit. The electrical device 1 has substantially the same dimensions as the electronic component 6 which it replaces.

The subject of this invention is also a method for modification of an electronic board (which can be used for a first application) to adapt it to the functioning of a different application. For example, the diagram in figure 4 is used by the Applicant to control a LED. With the modification shown in figure 5, the board can instead be used to control a turbidity sensor in a household appliance. Electronic boards of the type indicated herein can be used in various electrical/electronic applications not necessarily limited to the sector of household appliances. The method comprises the step of disconnecting from the board an electronic component 6 positioned in a first zone 70 of the board 7, said electronic component 6 being electrically and physically connected to at least a first, a second and a third contact 71, 72, 73 of the board 7. The method for the modification also comprises connecting the board 7, in said first zone 70, to an electrical device 1 having one or more of the technical features described above. The possibility of using the first electrical jumper 41 of the device 1 therefore allows the short-circuiting of two contacts of the board, obtaining a new board which is perfectly stable from a functional point of view. It is not, on the other hand, possible to propose the connection of a commercial resistance with 0 ohm directly between the two contacts of the board to be short-circuited. In fact, commercial resistances with 2 terminals have standardised dimensions and the pitch between the two contacts of the board is normally incompatible with the distance between the terminals of a two-terminal resistance. The step of connecting the electrical device 1 to the board comprises the step of electrically and physically connecting the third terminal 33 of said electrical device 1 to the third contact 73, the second terminal 32 of said electrical device 1 to the second contact 72, and the first terminal 31 of said electrical device 1 to the first contact 71.

Conveniently, all the electrical terminals of the electrical device 1 are connected to corresponding contacts on the board 7. This makes it possible to obtain a board that is more stable from the functional point of view and at the same time to make the connection of the electrical device 1 on the board 7 more mechanically stable. Conveniently, the above-indicated connections between the terminals of the electrical device 1 and the contacts of the board are made by soldering.

Conveniently, the electronic component 6 is a transistor (for example bjt or mosfet), a triac or an integrated circuit. A bjt transistor typically comprises three terminals, conventionally called base, collector and transmitter. An electrical control signal that arrives on the base typically makes it possible to control the passage of current between the collector and the transmitter. In a non-limiting embodiment, in a first application of the electronic board which comprises the assembly of the electronic component 6, said first contact 71 of the board is connected to the collector of the transistor while the second contact 72 of the board is connected to the transmitter of the transistor. The third contact 73 is instead connected to the base of the transistor. This makes it possible, replacing the transistor with the device 1, to short-circuit the first and second contacts 71, 72. On the new board obtained in this way, the electrical connection between the first and the second contacts 71, 72 will therefore be independent of the signal which reaches the third contact 73 (originally connected to the base of the transistor).

In an alternative embodiment, in a first application of the electronic board which comprises the assembly of the electronic component 6, said first contact 71 of the board is connected to the terminal MT1 of a triac while the second contact 72 of the board is connected to the terminal MT2 of the triac. The third contact 73 is instead connected to the gate of the triac. This makes it possible, replacing the triac with the device 1, to connect the first and second contacts 71, 72 independently of the signal which reaches the third contact 73.

The subject of this invention is also a method for modification of an electronic board if it is necessary to replace a component with just two electrical terminals. The subject of this invention is also a method for modification of an electronic board which can be used for a first application to adapt it to the functioning of a different application. The method comprises the following steps:

i) disconnection from the board of an electronic component 6 positioned in a first zone 70 of the board 7, said electronic component 6 being electrically and physically connected to at least a first and a second electrical contact 71, 72 of the board 7;

ii) connection to the board in the first zone 70 of an electrical device 1 comprising:

- an outer casing 2 ;

- at least one first and one second electrical connection terminal 31, 32 accessible from the outside of the casing 2 ;

- at least one first electrical jumper 41, positioned inside the casing 2, which electrically connects the first and second terminal 31, 32; said first electrical jumper 41, at 20°C, having an electrical resistance between 0 and 0.01 ohm. The step of connecting the electrical device 1 to the board comprises the step of electrically and physically connecting the first terminal 31 to the first contact 71 and the second terminal 32 to the second contact 72.

The electrical device 1 has substantially the same dimensions as the electronic component 6 which it replaces. This makes it possible to position the electrical device 1 without modifying the layout of the board. This also makes it possible to avoid unreliable connections to short-circuit two contacts on a board, which would lead to an increase of the instability of the board and the risk of unwanted short-circuits between two points on the board.

The invention as described herein brings numerous advantages.

In particular, it allows easy and rapid adaptation of existing electronic boards with minimal intervention. It also makes it possible to obtain a modified board with a high level of reliability .

It shall be understood that the invention described above may be modified and adapted in several ways without departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by other technically equivalent elements. In practice, all the materials used, as well as the dimensions, may vary according to requirements.

Claims

1. An electrical device comprising:

- an outer casing (2);

- a plurality of electrical connection terminals which protrude externally from the casing (2), said plurality of electrical connection terminals comprising at least one first, second and third terminal (31, 32, 33);

characterised in that it comprises at least one electrical jumper (41), positioned inside the casing (2), which electrically connects the first and second terminal (31, 32); said first electrical jumper (41), at 20°C, having an electrical resistance between 0 and 0.05 ohm; inside the casing (2) said third terminal (33) being electrically insulated from the first and the second terminals (31, 32) .

2. A device according to claim 1, characterised in that said plurality of terminals comprises at least one additional terminal which protrudes from the casing (2), said additional terminal inside the casing (2) being electrically insulated from all the other terminals of said plurality of terminals.

3. A device according to claim 1, characterised in that said plurality of terminals comprises at least one additional terminal, said additional terminal being connected to at least one of the remaining terminals, except for the third one (33), by means of an additional electrical jumper having a resistance between 0 and 0.05 ohm at 20°C, said additional electrical jumper being inside the casing (2) .

4. A device according to any of the foregoing claims, characterised in that the first connection terminal (31) does not intersect the imaginary extension of the second connection terminal (32), said extension being at right angles to the plane tangent to the casing (2) in the zone where the second terminal (32) protrudes externally from the casing (2).

5. A device according to any of the foregoing claims, characterised in that said casing (2) comprises an outer surface

(20) in turn comprising:

- first and second opposite bases (21, 22); - a side surface (23) developing between the first and second base (21, 22); the first, the second and the third terminal (31, 32, 33) extending externally from the casing (2) starting from said side surface (23).

6. A device according to claim 5, characterised in that the first and second base (21, 22) are substantially quadrilateral and the side surface (23) comprises a first, a second, a third and a fourth face (24, 25, 26, 27); among the first, the second and the third terminals (31, 32, 33) at least two terminals are on the first face (24) and the remaining terminal is on the third face (26); said third face (26) being opposite the first face (24) .

7. A device according to claim 1, characterised in that it has one of the following standardised dimensions: SOT-89, SOT-23, SOT-323, SOT-416, SOT-63, SOT-723, SOT-883, SOT-223,

DPAK, D2PAK, D3PAK, SOT-23-5, SOT-23-6, SOT-23-8, SOT-353, SOT- 363, SOT-563, SOT-665, SOT-666, SOT-886, SOT-891, SOT-953, SOT- 963.

8. A device according to claim 1, characterised in that it presents the dimensions of an electronic component belonging to one of the following standardised dimensional families: DIP, SOIC, SOJ, PLCC.

9. A method for the assembly of an electronic board comprising the step of connecting the board to an electrical device (1) according to any of the foregoing claims from 1 to 8; the step of connecting the electrical device (1) to the board comprises the step of electrically and physically connecting the first terminal (31) of said electrical device (1) to a first contact (71) on the board, the second terminal (32) of said electrical device (1) to a second contact (72) on the board, and the third terminal (33) of said electrical device (1) to a third contact (73) on the board.

10. A method according to claim 9, characterised in that all the electrical terminals of the electrical device (1) are connected to corresponding contacts on the board (7) .

11. A method for construction of a second electronic board using at least one printed circuit developed for a first electronic board, said first electronic board being usable for a first application and being destined to comprise:

- said printed circuit provided with predetermined electrical tracks ;

- a first electronic component (6) connected to said printed circuit in a first zone of said printed circuit and physically connected to a first, a second and a third contact (71, 72, 73) of the printed circuit;

said method comprising the step of assembling the second electronic board which can be used for a second application different from the first application; the step of assembling said second board comprising the step of: procuring at least the printed circuit of the first board and connecting it to an electrical device (1) according to any of the foregoing claims from 1 to 8 instead of to said electronic component (6); the step of connecting the electrical device (1) to said printed circuit comprises the step of connecting electrically and physically the third terminal (33) of said electrical device (1) to the third contact (73) of the printed circuit, the second terminal (32) of said electrical device (1) to the second contact (72) of the printed circuit, and the first terminal (31) of said electrical device (1) to the first contact (71) of the printed circuit.

12. A method according to claim 11, characterised in that said electronic component (6) is a transistor or a triac and comprises :

- an input of the electrical current;

- an output of the electrical current;

- a control port for the transfer of current from the input to the output;

in said first board the first and second contact (71, 72) of the printed circuit being connected one to the to said input and one to said output.

13. A method according to claim 11 or 12, characterised in that said electrical device (1) has substantially the same dimensions as the electronic component (6) which it replaces.