condensatori

Condensatori, known in English as capacitors, are passive two-terminal electrical components that store energy in an electric field created by charges on two conductors separated by a dielectric. When connected to a voltage source, charges accumulate on the plates and the device stores energy according to E = 1/2 C V^2, where C is the capacitance. They are designed to be charged and discharged repeatedly with minimal energy loss in ideal conditions.

Capacitance depends on the geometry of the conductors and the properties of the dielectric material between them. Capacitors are widely categorized by their dielectric: ceramic, film (such as polypropylene or polyester), electrolytic (aluminum, tantalum), mica, paper, and supercapacitors. Ceramic and film types are generally non-polar and suitable for high-frequency applications; electrolytic types provide large capacitance in a compact form but are polarized and have higher leakage and lower reliability in some conditions. Supercapacitors offer very high capacitance for energy storage but operate at moderate voltages and have longer charging times.

Key electrical characteristics include capacitance (C), rated voltage (Vmax), tolerance, leakage current, equivalent series resistance (ESR), and temperature coefficient. The dielectric influences many of these parameters. In circuits, condensatori are used for filtering and decoupling, coupling and signal shaping, energy storage in power supplies, and timing networks. Polarized electrolytic capacitors require correct polarity and can be sensitive to voltage reversal or overheating.

Historically, condensatori date to early capacitance experiments in the 18th century and have evolved into a wide range of types for modern electronics, from consumer devices to high-rereliability aerospace applications.