About Crystal microphone

1. CRYSTAL MICROPHONE
SUBMITTED BY:
GYAN JYOTI GOGOI.
POWIET, JORHAT
ASSAM

2. WORKING
Crystals which demonstrate the piezoelectric
effect produce voltages when they are deformed. The
crystal microphone uses a thin strip of piezoelectric
material attached to a diaphragm. The two sides of the
crystal acquire opposite charges when the crystal is
deflected by the diaphragm. The charges are proportional
to the amount of deformation and disappear when the
stress on the crystal disappears. Early crystal microphones
used Rochelle salt because of its high output, but it was
sensitive to moisture and somewhat fragile. Later
microphones used ceramic materials such as barium titan
ate and lead zirconated. The electric output of crystal
microphones is comparatively large, but the frequency
response is not comparable to a good dynamic

3. CONSTRUCTION

4. Crystal Microphone