Skip to main content

The National MagLab is funded by the National Science Foundation and the State of Florida.

Rheostat - 1820

The rheostat was developed in the mid-1800s by Charles Wheatstone as a means of varying resistance in a circuit.

Rheostat thumbnail

Most early rheostats consisted of a coil of resistance wire wound around an insulated tube above which a metal bar was positioned.

A sliding contact connected the wire to the bar and could be moved to change the amount of coiled wire an electric current traveled through before it was passed on to the bar, which was less resistant to flow.

The more the current has to flow through the coiled wire, the higher the resistance.