Zenith 2 Amp Rheostat

This is an older type high power variable resistor in a metal case.

The Video

View this video on Youtube.


The blue case is sheet steel, and contains numerous ventilation slots. Connections are made to the terminals on the end - one for the sliding contact and two others for each end of the resistance.
End to end resistance is 113 ohms, and the whole device is rated for 2 amps.


The resistance is formed from wire wrapped around a tubular ceramic former. The sliding contact has six sprung metal fingers which press onto the wire and a further spring to ensure good contact with the metal rod that it slides on.
The wire shows slight signs of wear, the rest of the device is in excellent condition and has probably had very little use.

These devices are only suitable for use at extra low voltages, and are intended for laboratory experiments or educational use.