User Manual

142 / 223
capacitor and works on the principle of a variable capacitance. It consists of two
plates, one fixed (called the back plate) and the other moveable (called the
diaphragm) with a small gap between them. An electric potential charges the plate.
When sound strikes the diaphragm it starts moving, thereby changing the
capacitance between the plates which in turn results in a variable electric current to
flow.
These microphones are widely used in electronic circuits to detect minor sounds or
air vibrations which in turn are converted to electrical signals for further use. The
two legs as shown in the image above are used to make electrical connection with
the circuit.
A solid conducting metal body encapsulates the various parts of the microphone.
The top face is covered with a porous material with the help of glue. It acts as a filter
for the dust particles. The sound signals/air vibrations passes through the porous
material and falls on the diaphragm through the hole shown in the image above.