A transducer is a device that usefully converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.
Transducers are often employed at the boundaries of automation, measurement, and control systems, where electrical signals are converted to and from other physical quantities (energy, force, torque, light, motion, position, etc.). The process of converting one form of energy to another is known as transduction.
Types
thumb|Mechanical transducer
- Mechanical transducers convert physical quantities into mechanical outputs or vice versa;
- Electrical transducers convert physical quantities into electrical outputs or signals. Examples of these are:
- a thermocouple that changes temperature differences into a small voltage;
- a linear variable differential transformer (LVDT), used to measure displacement (position) changes by means of electrical signals.
Sensors, actuators and transceivers
Transducers can be categorized by the direction information passes through them:
- A sensor is a transducer that receives and responds to a signal or stimulus from a physical system.