Potentiometers, rheostats and trimmers are three-terminal resistors that are used to measure or divide voltages, and to protect or control circuits. Potentiometers are variable resistors that are adjusted with a knob or dial. Potentiometers, rheostats and trimmers carry specifications for potentiometer category and actuator configuration. In terms of actuator configuration, choices include single-turn, multi-turn, and slide. With single-turn devices, the shaft rotation is limited to less than or equal to 360 degrees. By contrast, multi-turn potentiometers, rheostats and trimmers can be rotated multiple times, with as many as 15 or 20 turns from stop to stop. Slide-actuated products require the user to move a handle instead of rotating a knob.
Semec Trimming Potentiometers 3296, 3386, 3362, 3266 and 3006 are most popular products in the market.