Transducer

A device which converts a non-electrical signal into an electrical one.
It is generally a device that changes energy from one form to another.A microphone is an example of a transducer. It changes variations in air pressure into variations in electrical voltage.
There are many transducers in aircraft systems that are responsible for making and sending electrical signals to detect the status of their systems.Like a wheel speed transducer that generates an electrical signal based on the amount of rotation of the aircraft wheel.
Also for example pressure transducer and......
Transducers are voltage-output devices that can be used with simple signal conditioning but are more sensitive to electromagnetic interference. The electrical resistance of the connecting cable can cause significant errors if the cable is long. They require three or four connecting wires to supply power and deliver the output signal.