Transducer

A transducer is a device that converts one form of energy into another, usually for the purpose of measuring or exchanging information. There are several varieties of transducers:

• Photoelectric transducers convert electrical energy to light, or vice versa.
• Ultrasonic transducers convert mechanical waves (sound) into electrical signals.
• Antennas convert radio waves to electrical signals.
• Electrochemical transducers convert chemical composition information to electrical signals.
• Pressure transducers convert a pressure reading to an electrical signal.