What is the purpose of trimmer capacitor?
Trimmer capacitors are used to initially set oscillator frequency values, latencies, rise and fall times and other variables in a circuit. Should the values drift over time, these trimmer capacitors allow repairmen to re-calibrate equipment when needed.
What is the use of variable capacitor?
Variable capacitors are often used in L/C circuits to set the resonance frequency, e.g. to tune a radio (therefore it is sometimes called a tuning capacitor or tuning condenser), or as a variable reactance, e.g. for impedance matching in antenna tuners.
What are the types of variable capacitors?
These types of capacitors are classified into two types namely air trimmer & ceramic trimmer. This capacitor includes three leads where one lead is linked to the immobile part; the second lead is linked to the rotary and the last lead is common.
Where are the capacitors located on a trimmer?
Trimmer Capacitors Trimmer capacitors are miniature variable capacitors. Trimmer capacitors are mounted directly on the printed circuit board with a provision to vary their value using a small screwdriver. The trimmer capacitors are set during production or servicing of the electrical equipment and are not meant to be varied by the end user.
What kind of dielectric is used in trimmer capacitors?
The dielectric used could be air or ceramic. Trimmer capacitors can be made of semi-circular metal plates. One of the plates is fixed while the other can be rotated using a screwdriver. The capacitance changes when the shaft is rotated thereby increasing or reducing the amount of overlap between the two plates.
How many Pico farads are in trimmer capacitors?
To improve the precision of the capacitance values, simple gear mechanisms can be used that allow multiple turns between the lowest and highest settings. The value of trimmer capacitors is less than 100 pico farads. Trimmer capacitors are commonly used in various RF, VHF and microwave frequency band circuits.