How Trimmer Capacitor Used In Radio Tuning Circuits?

       Trimmer is a miniature adjustable electrical component, used to be set correctly when installed in some device, and never seen or adjusted by the device's user. We can see trimmers in the types of variable resistors (potentiometers), variable trimmer capacitor, or trimmable inductors. Speaking of variable capacitors, they are mostly used in radio tuning circuits and they are sometimes called “tuning capacitors.” They have very small capacitance values, typically between 100pF and 500pF. Many variable capacitors have very short spindles which are not suitable for the standard knobs used for variable resistors and rotary switches. It would be wise to check that a suitable knob is available before ordering a variable capacitor.

       Trimmer capacitor is the miniature variable capacitors, designed to be mounted directly onto the circuit board and adjusted only when the circuit is built. A small screwdriver or similar tool is required to adjust trimmers. The process of adjusting them requires patience, because the presence of your hand and the tool will slightly change the capacitance of the circuit in the region of the trimmer.