Question

Please explain me the use of rheostat and the types of rheostat.

Answer 1

A rheostat is a variable resistor which is used to control current. They are able to vary the resistance in a circuit without interrupting the flow of current

Types of Rheostats

1. Linear Rheostat:

These rheostats have a linear resistive path. The sliding terminal glides over this path. There are two fixed terminals however only one of the two is used. The other terminal is connected to the slider.

These are mostly used in laboratory applications. Mostly wire-wound resistive path along a linear cylinder shaped material, is used.

2. Rotary Rheostat

With full justice to its name, a rotary rheostat has a rotary resistive path. These are mostly used in power applications. These rheostats have a shaft on which the wiper is mounted. Wiper is nothing but the sliding contact for a rotary rheostat, which can rotate over ¾ of a circle.

The function and working principle are all same for both types of rheostats.

3. Preset Rheostat

When rheostats are used in a printed circuit board, they are used as trimmers or preset rheostats. Trimmers are nothing but a small rheostat, mostly used in calibration circuits. Two terminal trimmers are available, although in most cases three terminal potentiometer trimmer is used as a two terminal rheostat.