023 Introduction of common electronic components (G)

Introduction of common electronic components (G)

2. Capacitor

C. Classification of capacitor

(1) According to the structure of three categories: fixed capacitor, variable capacitor and fine tuning capacitor.
Variable capacitor: it is composed of a set of fixed plate and a set of movable plate, its capacity can be continuously changed with the rotation of the movable plate. Two sets of variable capacitors installed together coaxial rotation, called double connection. Variable capacitance media are air and polystyrene. Air medium variable capacitor is large in volume and small in loss, so it is used in valve radio. Polystyrene dielectric variable capacitors made of sealed, small size, used in transistor radios.
Semi-variable capacitor: also called trimmer capacitor. It is made of two or two sets of small metal shrapnel with a medium in between. Change the distance or area between the two pieces as you adjust. Its medium has air, ceramic porcelain, mica, film and so on.

(2) According to the shape: plug-in type, patch type (SMD).

(3) According to the purpose: high frequency bypass, low frequency bypass, filtering, tuning, high frequency coupling, low frequency coupling, small capacitor.

(4) According to the dielectric material is divided into: ceramic medium, mica, paper, film, electrolytic capacitor.

(5) Mica capacitor: a capacitor with mica as a dielectric. Excellent performance, high stability, high precision.

(6) Ceramic capacitor: ceramic material with high dielectric constant and low loss, small volume and small inductance.

(7) Paper capacitor: the electrode of paper capacitor is made of aluminum foil or tin foil, the insulation medium is wax-soaked paper, folded into a cylinder, coated with moisture-proof material, sometimes the shell is sealed with iron paper, folded into a cylinder, coated with moisture-proof material, sometimes the shell is sealed with iron shell to improve moisture resistance. Low price, large capacity. Shell to improve moisture resistance. Low price, large capacity.

(8) Film capacitors: various capacitors made of polystyrene, polytetrafluoroethylene or polyester organic films instead of paper media. Small size, but large loss, unstable. Quality, made of a variety of capacitors. Small size, but large loss, unstable.

(9) Electrolytic capacitor: capacitor with aluminum, pole, saw, titanium and other metal oxide film as the medium. Large capacity, poor stability. (pay attention to polarity when using) large, poor stability.

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Post time: Jun-19-2022