GB2315183A - Coil formers for loudspeaker drive units - Google Patents
Coil formers for loudspeaker drive units Download PDFInfo
- Publication number
- GB2315183A GB2315183A GB9614396A GB9614396A GB2315183A GB 2315183 A GB2315183 A GB 2315183A GB 9614396 A GB9614396 A GB 9614396A GB 9614396 A GB9614396 A GB 9614396A GB 2315183 A GB2315183 A GB 2315183A
- Authority
- GB
- United Kingdom
- Prior art keywords
- body portion
- coil former
- coil
- voice coil
- former
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/06—Arranging circuit leads; Relieving strain on circuit leads
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
- H04R9/02—Details
- H04R9/04—Construction, mounting, or centering of coil
- H04R9/046—Construction
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
Abstract
A coil former 1 for winding the voice coil 2 of a loudspeaker drive unit comprises a body portion 3 for receiving the winding and flexible support means 4 projecting from the body portion and integral with it, to support electrical connections to the voice coil 2. The support means comprises two diametrically opposed flexible printed circuit boards, carrying printed conductors to make electrical contact with the voice coil. This invention has a particular application in tweeter drive units, where mechanical failure of the lead out connections between the voice coil and the tweeter terminals is caused by metal fatigue.
Description
Coil Formers for Loudspeaker Drive Units
This invention relates to coil formers for loudspeaker drive units.
In a loudspeaker drive unit, it is common practice to wind the voice coil on a former and connect the voice coil to terminals on the drive unit by means of lead out connections.
It is an object of the invention to provide an improved coil former for a loudspeaker drive unit.
The present invention provides a coil former for winding the voice coil of a loudspeaker drive unit, the former comprising a body portion for receiving the winding and flexible support means projecting from the body portion to support electrical connections to the voice coil.
Such a coil former is of particular value for use in high frequency loudspeaker drive unit, commonly called a "tweeter".
The invention is based on the realization that the majority of failures of tweeters are caused by mechanical failure of the lead out connections between the voice coil itself and the terminals of the tweeter. The failure is believed to be caused by metal fatigue of the connections owing to the very high number of cycles of operation made by the voice coil to which they are attached.
With a coil former according to the invention the lead out connections are provided with support by the flexible support means and are better able to withstand the cyclic stresses to which they are subjected.
Preferably, the flexible support means is integral with the body portion. Such an arrangement avoids adhesive connections which might become detached in use.
Preferably, the body portion comprises a ring of insulating material. Such a ring can made very simply by wrapping a strip of flexible material around a mandrel and winding the voice coil over the ring.
Preferably, the flexible support means comprises a pair of flexible legs. One leg can then be used for each connection to the voice coil.
Advantageously, the legs are located diametrically opposite each other on the body portion. Such a construction has the advantage of being symmetrical.
Preferably, both legs project from the same side of the body portion.
Advantageously, a respective slot is provided on each side of each leg where the legs join the body portion. Such slots enable the legs to bend in a gentle arc whilst avoiding local stress where they join the body portion.
Preferably, the flexible support is in the form of a flexible printed circuit board and carries printed conductors for making connection to the voice coil.
There is then no problem of mounting conductors or the flexible support means.
Advantageously, the printed conductors terminate at the opposite side of the body portion to the side from which the legs project. The terminations of the printed conductors are likely to be stiffer because of the need to make connections to them and it is therefore an advantage to keep the connections away from the location where the legs join the body portion.
Preferably, a respective bonding pad is provided at each end of each printed conductor. It is then a simple matter to make connections by soldering to the bonding pads.
Preferably, the printed circuit board comprises copper clad polyimide.
The invention also provides a voice coil for a loudspeaker drive unit comprising a coil former as claimed in any preceding claim and a winding wound on the body portion with electrical connections to the winding supported on the flexible support means.
The invention also provides a loudspeaker drive unit including a voice coil as defined above.
Advantageously the loudspeaker drive unit the unit is a tweeter. The invention is of particular benefit in the construction of tweeters from the reasons explained above.
A coil former constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawing, in which:
Fig. 1 is a diagrammatic cross-section through the coil former and shows a voice coil winding and dome diaphragm applied to the former;
Fig. 2 is a partial view, to an enlarged scale, of a strip of flexible printed circuit board for making the coil former; and
Fig. 3 is an overall view of the strip shown in Fig. 2.
Referring to the accompanying drawings, a coil former 1 for winding the voice coil 2 of a loudspeaker drive unit comprises a body portion 3 for receiving the voice coil winding 2 and flexible support means 4 projecting from the body portion to support electrical connections to the voice coil. A dome diaphragm 10 is mounted on the former 1.
The flexible support means 4 are integral with the body portion 3 and comprise a pair of flexible legs 4A, 4B. The legs 4A, 4B are located diametrically opposite each other on the body portion 3 and both legs project from the same side of the body portion..
The body portion 3 comprises a ring of insulating material formed by wrapping the strip shown in Figures 2 and 3 around a mandrel (not shown). It is not essential to secure the adjacent ends of the strip to each other although this may be done if desired,
As shown in Figure 2, a respective slot 5, 6 is provided on each side of each leg 4A, 4B where the legs join the body portion 3.
The flexible support is in the form of a flexible printed circuit board comprising copper clad polyimide and carries printed conductors 7 for making connection to the voice coil 2.
As shown in Figure 2, the printed conductors 7 terminate at the opposite side of the body portion 3 to the side from which the legs project and a respective bonding pad 8 is provided at each end of each printed conductor 7. The remainder of the printed conductor has an insulating layer over it.
A practical example of the coil former had the following materials and dimensions:
Kapton polyimide 35m copper clad single-sided flexible printed circuit board with printed cover coating to total board thickness of 0.08mm. Dimensions in millimetres for the reference letters marked in the drawings:
A = 1.70, B = 2.0, C = 2.8, D = 2.0, E = 1.50, F = 2.50, G = 101.50, H = 50.90, I = 20 and J = 5.90.
Claims (15)
1. A coil former for winding the voice coil of a loudspeaker drive unit, the former comprising a body portion for receiving the winding and flexible support means projecting from the body portion to support electrical connections to the voice coil.
2. A coil former as claimed in claim 1, wherein the flexible support means is integral with the body portion.
3. A coil former as claimed in claim 1 or claim 2, wherein the body portion comprises a ring of insulating material.
4. A coil former as claimed in any preceding claim, wherein the flexible support means comprises a pair of flexible legs.
5. A coil former as claimed in claim 4, wherein the legs are located diametrically opposite each other on the body portion.
6. A coil former as claimed in claim 4 or claim 5, wherein both legs project from the same side of the body portion.
7. A coil former as claimed in claim 4, claim 5 or claim 6, wherein a respective slot is provided on each side of each leg where the legs join the body portion.
8. A coil former as claimed in any preceding claim, wherein the flexible support is in the form of a flexible printed circuit board and carries printed conductors for making connection to the voice coil.
9. A coil former as claimed in claim 8 when dependent on claim 6, wherein the printed conductors terminate at the opposite side of the body portion to the side form which the legs project.
10. A coil former as claimed in claim 8 or claim 9, wherein a respective bonding pad is provided at each end of each printed conductor.
11. A coil former as claimed in claim 7, wherein the printed circuit board comprises copper clad polyimide.
12. A coil former substantially as herein described with reference to, and as illustrated by, the accompanying drawing.
13. A voice coil for a loudspeaker drive unit comprising a coil former as claimed in any preceding claim and a winding wound on the body portion with electrical connections to the winding supported on the flexible support means.
14. A loudspeaker drive unit including a voice coil as claimed in claim 13.
15. A loudspeaker drive unit as claimed in claim 14, wherein the unit is a tweeter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9614396A GB2315183A (en) | 1996-07-09 | 1996-07-09 | Coil formers for loudspeaker drive units |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9614396A GB2315183A (en) | 1996-07-09 | 1996-07-09 | Coil formers for loudspeaker drive units |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9614396D0 GB9614396D0 (en) | 1996-09-04 |
| GB2315183A true GB2315183A (en) | 1998-01-21 |
Family
ID=10796606
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9614396A Withdrawn GB2315183A (en) | 1996-07-09 | 1996-07-09 | Coil formers for loudspeaker drive units |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2315183A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108600932B (en) * | 2018-03-29 | 2023-12-08 | 山东共达电声股份有限公司 | Moving coil, manufacturing method thereof and loudspeaker |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0197605A2 (en) * | 1985-03-30 | 1986-10-15 | Blaupunkt-Werke GmbH | Moving part of a dynamic loudspeaker |
| US4680800A (en) * | 1984-04-24 | 1987-07-14 | Wharfedale Loudspeaker Limited | Moving-coil loudspeaker unit |
| US5008945A (en) * | 1988-05-23 | 1991-04-16 | Pioneer Electronic Corp. | Water-proof speaker unit |
| US5249236A (en) * | 1989-12-01 | 1993-09-28 | Kabushiki Kaisha Kenwood | Wiring structure of loudspeaker |
| EP0622970A1 (en) * | 1993-04-19 | 1994-11-02 | Kabushiki Kaisha Kenwood | Voice coil and loudspeaker structure |
-
1996
- 1996-07-09 GB GB9614396A patent/GB2315183A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4680800A (en) * | 1984-04-24 | 1987-07-14 | Wharfedale Loudspeaker Limited | Moving-coil loudspeaker unit |
| EP0197605A2 (en) * | 1985-03-30 | 1986-10-15 | Blaupunkt-Werke GmbH | Moving part of a dynamic loudspeaker |
| US5008945A (en) * | 1988-05-23 | 1991-04-16 | Pioneer Electronic Corp. | Water-proof speaker unit |
| US5249236A (en) * | 1989-12-01 | 1993-09-28 | Kabushiki Kaisha Kenwood | Wiring structure of loudspeaker |
| EP0622970A1 (en) * | 1993-04-19 | 1994-11-02 | Kabushiki Kaisha Kenwood | Voice coil and loudspeaker structure |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9614396D0 (en) | 1996-09-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |