1. Structural characteristics of the capacitor

The capacitor is composed of two metal electrode plates which are close to each other and sandwiched by a layer of insulating medium. When a voltage is applied to the two electrodes of the capacitor, the capacitor can store electrical energy.

Capacitors have the characteristics of "AC, DC blocking". The polarity and voltage of the DC current are fixed and cannot pass through the capacitor. The polarity of the alternating current and the magnitude of the voltage are constantly changing, so that the capacitor can be continuously charged and discharged to form a charging and discharging current.

2. Capacitor function

Capacitors are widely used in various high and low frequency circuits and power supply circuits, decoupling (referring to the method of eliminating or mitigating interaction between two or more circuits in some way), coupling (connecting two or more circuits) Method of affecting each other) filtering (filtering out interference signals, clutter, etc.), bypass (parallel to a component or a circuit, one of which is grounded), resonance (referring to parallel or in series with the inductor, The phenomenon that the oscillation frequency is the same as the input frequency is a phenomenon that occurs, for example, tuning to select the radio frequency, buck, timing, and the like.