An adjustable resistor used to regulate current. Rheostats can be metallic, carbon or electrolytic systems. The metallic rheostat uses a metal wire or ribbon and a sliding contact such that the length of the wire from switch to contact increases as the dial is turned. This increases the resistance and decreases the current output. Rheostats were first used for light dimmer switches in Chicago's F.G. Robie house designed by Frank Lloyd Wright in 1909.
Synonyms and Related Terms
rhéostat (Fr.); reóstato (Port.);