AU5624798A

AU5624798A - Movable coil for loudspeakers and microphones

Info

Publication number: AU5624798A
Application number: AU56247/98A
Authority: AU
Inventors: Dragic Dragicevic
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-02-21
Filing date: 1998-01-27
Publication date: 1998-09-09
Also published as: EP0861013A1; WO1998037734A1; CA2320150A1; EA199900760A1; EP0962121A1; YU6497A

Description

The area of engineering the invention relates to

Movable coil for loudspeakers and microphones

The invention belongs to the area of electrical engin ering and electroaeoustics and relates to loudspeakers and microphones with movable coils designed based on electrically conductive strip.

The invention resolves the problem of more precise conversion of electrical signals into sound waves in the case of loudspeakers, and more precise receiving of sound waves and their conversion into electrical signals in the case of microphones.

The movable coil of a loudspeaker allows electrical signals to. be converted into sound waves, whereas the coil of a microphone turns the sound waves into electrical signals.

The known designs of the loudspeaker and microphone movable coil are based on a rectangular wire, with the narrow side adjacent to the coil mounting and wound coil-lo-coil in one row, or made of a round wire wound coil-to-coil in one or more rows. Both these designs have a long coil, and with the round wire there are voids between coils, so that end coils at both ends are out of the permanent magnetic field. Λs the coil assembly moves, the number of cυils not affected by the magnetic field increases and causing thereby less precise turning of electric signals into sound waves, and vice- versa - less precise turning of sound waves into electric signals.

The movable coil for loudspeakers and microphones is made in two ways, and consists of electrically conductive strip wound with one or more beginnings, laid one over the other and with the strip folded or twisted, once or more times along its longitudinal axis and laid with its wider side on the coil carrier. With the first method of making the coil, the strip is wound coil over the coil (in a cross section appears like strip spiral). One or more spirals may be wound one next to the other depending on the planned power and Ohm rating of the coil. With the other method, the strip is wound coil-lo-coil in one or more rows. The advantages of these coils are: production and winding tooling are cheaper, each coil is equally located within the permanent magnetic field in the case of the first production method.and with the other production method a majority of coils is within the field, so that the coil in loudspeakers allows higher dynamics, higher efficiency and precise turning of electric signals into sound waves, as well as higher sensitivity and precise turning of sound waves into electric signals in the case of microphone. Short Description of figures/Drawings

The invention is described in details on an example of the design shown is drawings:

Fig.l -Represents a longitudinal cross section of the loudspeaker and microphone coil with the movable coil system and the coil wound coil over the coil in one spiral.

Fig.2 -Represents a longitudinal cross section of the loudspeaker and microphone coil wound coil over the coil in several spirals one next to the other.

Fig.3 -Represents a longitudinal cross section of the loudspeaker and microphone coil wound coil-to-coil one row.

Fig.4 -Represents a longitudinal cross section of the loudspeaker and microphone coil wound coil-to-coil in several rows.

Fig.5 -Represents a cross section of the strip twisted along its own axis.

Fig.6 -Represents a cross section of the strip folded along its own longitudinal axis.

Fig.7 -Represents the strip having two beginnings for simultaneous coil winding.

Fig.1,2,3,4 -Represent the coil having one beginning for winding.

Fig.l shows a longitudinal cross section of the loudspeaker and microphone with the moving sistem and coil assembled of electrically conductive strip (l),coil (2), coil carrier (3), membrane (4), centering piece (5 ), permanent magnet (6) with magnet poles extensions (7).

In compliance with the concept of this invention, the coil would be wound in two ways with an electrically conductive strip having one beginning ( 1 ) (Figs.1,2,3,4), with two beginnings of the strip laid one over the other for simultaneous winding (Fig.7), and with the strip folded once or several times along its own axis (Fig.5), or with the strip twisted once or several times along its own axis (Fig.6), the strip beign laid with the wider side on the coil carrier (3). For the first method of making the coil, select the sn p type (Fig.5,6,7) and wind coil over the coil (in the cross section the coil would appear like a strip spiral) (Fig. l) wound in one or several spirals one next to the other to obtain the planned power and Ohm rating of the coil (2) (Fig.2). For the second method of making the coil, select the type of the strip and wind coil-to-coil in one row (Fig.3) or in several rows (Fig.4) on the coil carrier (3) (which is not absolutely necessary since the coil can be fitted directly) and fix the coil with the carrier to the membrane (4) and center it with the centering piece (5) at the level and between the permanent magnet pole extensions N and S (7). In compliance with the accomplishment of the invention, the movable coil is wound with electrically conductive strip having one beginning ( 1 ) with the wider side of the strip laid on the coil carrier (3). With the first method, the strip is wound coil over the coil as a strip spiral (2)(Fig. l ), or the coil is wound in several spirals (2) (Fig.2). With the second method l making the coil, the strip is wound coii-to-coil in one row (2) (Fig.3), or in several rows (2) (Fig.4) on the coil carrier (3), the coil with the carrier being fixed to the membrane (4) and centred by means of the centering piece (5) at the level and between the magnet pole extensions N and S (7).

Claims

Patent Claims

1. Movable coil for loudspeakers and microphones made in two ways and consisting of an electrically conductive strip (with one beginning) (1 ) Figs.1,2,3,4 and with several beginnings laid one over the other (Fig.7) and form the strip folded once or several times along its own axis(Fig.5), or from the strip twisted once or several times along its own axis (Fig.6). With either of these methods, the strip is laid with its wider side on the coil carrier, so that in the case of the first method it is wound coil over the coil as a strip spiral (Fig. l) or in several strip spirals (Fig.2), whereas with the second method the strip is wound with its wider side coil-to-coil in one row (Fig.3 ) or in several rows (Fig.4).

2. Movable coil in accordance with claim 1, characterized by that the strip has one beginning (1 ) (Figs.1,2,3,4) or several beginnings of the strip laid one over the other (Fig.7).

3. Movable coil in accordance with claim 1 , characterized by that the strip is folded once or several limes along its londgiludinal axis (Fig.5).

4. Movable coil in accordance with claim 1 , characterized by that the strip is twisted once or several limes around its own axis (Fig.6).

5. Movable coil in accordance with claim 1 , characterized by that the strip in any of the above described alternatives is laid with its wider side on the coil carrier (3).

6. Movable coil in accordance with claim 1 , characterized by that it is wound coil over coil in the form of a strip spiral (2) (Fig.l).

7. Movable coil in accordance with claim 1, characterized by that it is wound in several spirals one next to the other (2) (Fig.2).

8. Movable coil in accordance with claim 1 , characterized by that the strip is wound coil-to-coil in one row (2) (Fig.3).

9. Movable coil in accordance with claim 1 , characterized by that the strip is wound is several rows (2) (Fig.4). AMENDED CLAIMS

[received by the International Bureau on 6 May 1998 (06.05.98); original claims 1-9 replaced by amended claims 1-2 (1 page)]

1. Movable coil for loudspeakers and microphones characterized in that it consists of an electrically conductive strip with one beginning or of several conductive strips with several beginnings laid one over the other or from a strip folded at least once along at least one its longitudinal axis, whereby the strip is laid with its wider side on the coil carrier, so that it is wound coil over coil as one strip spiral, or in several strip spirals one within another.

2. Movable coil in accordance witi claim 1 , characterized that it consists of plurality of mutually connected coils separated by gaps.

STATEMENT UNDER ARTICLE 19

I enclose herewith amended claims 1 and 2. Claims 1 to 9 on file should be replaced by amended claims 1 to 2, now enclosed.

The amended claims 1 and 2 are actually reworded originally filled claims 1 and 7. The purpose of this amendment is to show a clear difference between this invention and the prior art cited in the International Search Report.

The first essence of this invention is in using one electrically conductive strip to make a movable coil whereby that strip is wound at least once around a bobbin, and preferably more than once.

The second essence of this mvention is that the strip is unfolded or folded once or more times along one or more longitudinal axes, before winding.

The third essence of this invention is that the movable coil is made of a plurality of coils defined in first and second essence of this invention, wound one next to the other around the bobbin, with a gap between the neighboring coils.

Practically it is my intention to retain Fig.1,2,5,6 and 7 and to abandon Fig.3 and 4 as contained in the prior art.