We offer a wide range of rheostats, with power ratings from 25W to 1kW. Track resistances range from 0.5Ohm to 50kOhm. Like potentiometers, rheostats have a uniform resistance track and a sliding contact – however they are connected into an external circuit differently, and they have a different function. They have two terminals rather than three, where one terminal is connected to the resistance track and the other to the sliding contact. As two-terminal devices they are wired in series with a load such as a lamp. Moving the sliding contact alters the series resistance in circuit, controlling the level of current flowing through the lamp and therefore its brightness.
Types of rheostats
Rotary Rheostats are usually used in power applications; as the name suggests, their resistance tracks are rotary. Linear Rheostats have a linear movement for changing the resistance path length and therefore the resistance. This type is usually found in laboratory applications. Preset Rheostats are usually found on printed circuit boards, and used for calibration purposes.
Rheostat applications
Rheostats are used in dimmer circuits, heaters and ovens, and speed control circuits for motors. They are also used for easily varying currents in teaching applications.
