Quick Guide to Trimmer Capacitors

This post is a quick guide to trimmer capacitors!

As you already know, trimmer capacitor is a variable capacitor which can be used to trim the performance of both active and passive circuits.

Trimmer capacitors typically cover a capacitance range of 1 pF to 2 pF but can extend up to 200 pF or more.

While a fixed capacitor is essentially two fixed metal plates that hold charge, in a trimmer capacitor the plates (the stator and rotator plates) are either adjusted in distance from each other or the amount of exposed area is shifted to change the amount of capacitance.

Also, like a fixed capacitor, some form of dielectric such as air, ceramic, glass, polytetrafluoroethylene, or sapphire is used as electrical insulation between the plates or other metalized surfaces.

Further Reading ↗ https://blog.knowlescapacitors.com/blog/your-quick-guide-to-trimmer-capacitor-selection-part-1

Note that there are a variety of trimmer types available. What is important is choosing the right one for each application.

Each of the trimmer capacitor types has its positive and negative aspects, and some are better suited to particular circuits than others. Understanding how to make the most of a trimmer capacitor involves an array of choices in packages, dielectric materials, and performance parameters.

Trimmers are available in precision Multi-Turn and Half/Single turn formats. Ceramic half-turn trimmers are the most common types as they are well suited to applications in which low cost and small size are the overriding concerns.

At higher frequencies, a multi-turn trimmer with Air, Teflon or Sapphire dielectrics provides the best solution. In an air trimmer, capacitance is created by a movable set of concentric metal rings fitted into a fixed set of parallel rings. As the rings mesh, capacitance increases. A fine-thread screw provides many turns of resolution for setting to the exact desired value.

Learn More ↗ https://www.mwrf.com/technologies/components/article/21846602/evaluating-trimmer-capacitor-choices

And see the datasheet of muRata TZC3 series ceramic trimmer capacitors in PDF