transducer
1. A device for converting sound, temperature, pressure, light
or other signals to or from an electronic signal.
2. {Finite State Machine}.
This term is used particularly in language theory where
automata are often considered as {abstract machine}s capable
of recognising the language defined by a {regular expression}.
[M. Crochemore "tranducters and repetitions",
Theoritical. Comp. Sc. 46 (1986)].
(1995-02-15)