rheostat
Datecirca 1925
Inventory NumberWJ0132
ClassificationRheostat
Subject
Manufacturer
Central Scientific Company
1889 - 2000
Cultural Region
Place of Origin
Dimensions13.2 × 36.5 × 9.8 cm (5 3/16 × 14 3/8 × 3 7/8 in.)
cylinder diam.: 5.2 cm (2 1/16 in.)
cylinder diam.: 5.2 cm (2 1/16 in.)
Material
Bibliography
DescriptionThis is a slide-wire type rheostat. It is supported by four feet, each having a hole so the rheostat can be bolted down. A wire is wound on a porcelain tube to ensure insulation. At each end of the wire is a terminal. An electric point contact slides on a rod over the wire. At one end of the slider rod is a third terminal, so this rheostat can also be used as a potentiometer. The resistance of this rheostat is 96 ohms for a current of 2.2 amps.
Current is applied to one of the wire's terminals. It passes through the wire and is picked up by the point contact on the slider, exiting from the terminal at the end of the slider rod. The further away the slider gets from the current's point of entry, the lesser the it is at the exit.
Current is applied to one of the wire's terminals. It passes through the wire and is picked up by the point contact on the slider, exiting from the terminal at the end of the slider rod. The further away the slider gets from the current's point of entry, the lesser the it is at the exit.
Signedon slider: CENTRAL SCIENTIFIC CO.
FunctionA rheostat functions as a variable resistance or as a voltage divider. If one end of the metal strip and the electrical contact suspended from the bar are connected to a circuit, the rheostat works as a variable resistance. It can be altered by moving the point of contact with the strip around the cylinder. If one connects the other end of the metal strip, the movable contact becomes a voltage divider.
ProvenancePsychology Department, William James Hall, Harvard University.
James G. Biddle Company
Date: circa 1920
Object number: RS0774
Rudolph Koenig
Date: circa 1863
Accessories: repeater (item 8000b)
Object number: 8000a
Central Scientific Company
Date: circa 1920
Object number: 2007-1-0114