Transducer

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This article is about an engineering device. For the similarly named concept in computer science, see Finite state transducer.

A transducer is a device that converts one form of energy to another. Usually a transducer converts a signal in one form of energy to a signal in another.[1]

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.).

Types of Transducers[edit]

Active Transducers[edit]

Active transducers convert energy directly from one form to another. They require no external power source to operate. For example, a thermocouple converts a temperature differential directly into an (resistance which can be measured by the amount of electrical voltage which it passed thru) electrical voltage.

Passive Transducers[edit]

Passive transducers produce a change in some passive electrical quantity, such as capacitance, resistance, or inductance, as a result of stimulation. These usually require additional electrical energy for excitation.

Sensors[edit]

A sensor is a transducer whose purpose is to sense (i.e. detect) some characteristic of its environs; it is used to detect a parameter in one form of energy and report it in another, often an electrical signal. For example, a pressure sensor might detect pressure (a mechanical form of energy) and convert it to electrical signal for display at a remote gauge. Transducers are widely used in measuring instruments.

Actuators[edit]

An actuator is a type of motor that is responsible for moving or controlling a mechanism or system.

It is operated by a source of energy, typically electric current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion. An actuator is the mechanism by which a control system acts upon an environment. The control system can be simple (a fixed mechanical or electronic system), software-based (e.g. a printer driver, robot control system), a human, or any other input.

Bidirectional[edit]

Bidirectional transducers convert physical phenomena to electrical signals and also convert electrical signals into physical phenomena. Examples of inherently bidirectional transducers are antennas, which can convert conducted electrical signals to or from propagating electromagnetic waves, and voice coils, which convert electrical signals into sound (when used in a loudspeaker) or sound into electrical signals (when used in a microphone). Likewise, DC electric motors may be used to generate electrical power if the motor shaft is turned by an external torque.

Ideal Transducer Characteristics[edit]

Applications[edit]

Transducers are used in electronic communications systems to convert signals of various physical forms to electronic signals, and vice versa. In this example, the first transducer could be a microphone, and the second transducer could be a speaker.

See also[edit]

References[edit]

  • Agarwal, Anant. Foundations of Analog and Digital Electronic Circuits.Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 2005, p. 43.
  1. ^ Agarwal, Anant. Foundations of Analog and Digital Electronic Circuits.Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 2005, p. 43

External links[edit]