| (19) |
 |
|
(11) |
EP 0 339 820 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
20.03.1991 Bulletin 1991/12 |
| (43) |
Date of publication A2: |
|
02.11.1989 Bulletin 1989/44 |
| (22) |
Date of filing: 10.04.1989 |
|
| (51) |
International Patent Classification (IPC)4: H04R 9/02 |
|
| (84) |
Designated Contracting States: |
|
AT BE DE ES FR GB IT NL SE |
| (30) |
Priority: |
26.04.1988 GB 8809805
|
| (71) |
Applicants: |
|
- Gabr, Saad
Camberley
Surrey (GB)
- Gabr, Yasser
Camberley
Surrey (GB)
|
|
| (72) |
Inventors: |
|
- Gabr, Saad
Camberley
Surrey (GB)
- Gabr, Yasser
Camberley
Surrey (GB)
|
| (74) |
Representative: Purvis, William Michael Cameron et al |
|
D. Young & Co.,
21 New Fetter Lane
London EC4A 1DA
London EC4A 1DA (GB) |
|
| |
|
| (54) |
Electromagnetic transducer |
(57) In a moving coil electro magnetic transducer, a top plate (12), a back plate (16)
and a pole piece (18) of the magnetic circuit of a magnet (14) may act as a shorted
secondary coil around a moving coil (24). To prevent current flow in such a secondary
coil wasting energy, the invention provides that at least one and preferably all such
components are made electrically discontinuous by providing them with a radial slit
(20) thereby to reduce energy dissipated by induction.