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Re: Young Physicists/animation/loudspeaker



At 06:56 9/23/98 +0930, Scott wrote:
... One of my year eleven students is trying to find some
historical info on the invention of the loudspeaker (as an application of
magnetic fields), try as we may we can get nothing from the texts available
to us or from the internet. Again any help on this would be greatly
appreciated.

Thanks in advance
Scott.

The telephone earpiece was in use when broadcast radio provided a new use
for them: first as earphones or headphones, then with a tumbler or dish or
horn to broadcast the sound. By 1925, the solenoid coil with the iron
diaphragm, the 'moving iron' speaker arrangement, was giving way to the
moving coil speaker with a permanent magnet, or with an electromagnet.

Brian
brian whatcott <inet@intellisys.net>
Altus OK