Page 241 - Concise Encyclopedia of Robotics

Tone Piezoelectric Transducer
generator
Modulated
light source

Frequency
sensitive
amplifier
Photodetector

Microcomputer

Locomotion
system
Light-scattering
surface
Photoelectric proximity sensor

If an AC signal is applied to the plates, it causes the crystal to vibrate
“in sync” with the current. The result is that the metal plates vibrate also,
producing an acoustic disturbance.
Piezoelectric transducers are common in ultrasonic applications, such
as intrusion detectors and alarms. They are useful in robotic systems be-
cause they are small, light in weight, and demand little current for their
operation. They are sensitive and can function underwater. Compare
DYNAMIC TRANSDUCER and ELECTROSTATIC TRANSDUCER.

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