The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Just about any device that is used to convert energy from one form into another can be called a transducer. Most electronic measuring devices use some type of transducer in order to display their measurements.
An example of one type of transducer is an automobile's fuel gauge. In this system a float within the fuel tank is allowed to rise and fall according to the amount of fuel beneath it. The rise and fall is measured by a potentiometer as relative displacement, and the electrical signal produced by the potentiometer is used to control the position of the dashboard's fuel gauge. Like most transducers, this system utilizes a two-step process by which first a mechanical and then an electrical element are used to produce an electrical signal.
The transducer described above would be called a potentiometric transducer, since it uses a potentiometer as its electrical element. Other types are the inductive and capacitive transducers, strain gauges, ultrasonic transducers, as well as anemometers, flowmeters, and accelerometers.
One of the first kinds of transducers was the microphone, developed in the late 1800s by the American inventor Thomas Edison. The microphone converts sound waves by allowing them to vibrate a sensitive cone, later changing that vibration into an electrical signal. In order to reproduce the sound, one must use a speaker (another type of transducer) to reverse the process; here, the same signal is used to vibrate a similar cone, thus creating sound waves.
Another, more recent variety of transducer is the photoelectric cell. These solar cells consist of certain elements--often selenium or silicon--that readily lose electrons when exposed to bright light, particularly sunlight. The liberated electrons will produce an electric current across the cell. Photoelectric cells are often employed as light meters, measuring the intensity of light by recording the strength of the electric current it produces. A cousin to the photoelectric cell, the photovoltaic cell, is also used to convert sunlight into usable energy; though usually encountered in watches and pocket calculators. Photovoltaic cells have shown promise as a potential replacement for fossil fuels when assembled into large solar arrays.