Trimmer-Variable Capacitor

Description

A trimmer variable capacitor (or simply a “trimmer”) is a small, adjustable capacitor used for fine-tuning circuits during manufacturing or maintenance. Unlike the large tuning knobs you might find on an old radio, trimmers are “set and forget” components—usually adjusted once with a screwdriver and then left alone.

How They Work

Trimmers consist of two sets of metal plates separated by a dielectric material (like ceramic, mica, or plastic). When you turn the adjustment screw, the overlap area between the plates changes, which varies the capacitance.