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Microphone.
The microphone
works by producing a small induced
voltage in a coil
from the effect of sound
waves hitting a diaphragm.
It is very similar to a loudspeaker
in reverse
with a diaphragm instead of a paper
cone.
This type of microphone is called a moving
coil microphone.
The sound waves
strike the diaphragm and move
it
backwards and forwards
at the same frequency
as the sound
(like the way the ear drum is moved inside the ear).
The moving diaphragm moves the coil
backwards and forwards
which induces a changing
current at the same frequency
as the sound.
This changing current (called the signal)
is sent to an amplifier
which makes the changing current big enough to be used
for recording or to drive loudspeakers.
The
loudspeaker reconverts the changing
current
back into the original sound.
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Copyright © 2007 Dr. Colin France. All Rights Reserved.