kapacitních

Kapacitní is an adjective used in physics, electronics and engineering to describe phenomena, devices or methods that rely on capacitance, the ability to store electric charge between conductive bodies separated by a dielectric. In Czech, kapacitní terms appear in expressions such as kapacitní senzor, kapacitní dotykový panel or kapacitní měření.

Capacitance is the property of a system to store electric charge for a given voltage. A simple capacitor consists of two conductors (plates) with a dielectric between them. The capacitance C depends on geometry and the dielectric constant: C = ε0 εr A / d. The SI unit is the farad (F), with practical circuits using picofarads to nanofarads (pF–nF). Energy stored is E = 1/2 C V^2.

In practice, the term kapacitní also refers to devices and sensors that operate through changes in capacitance. Kapacitní capacitors store energy; kapacitní senzory detect changes in capacitance caused by the presence or proximity of objects, especially a human finger. This principle underpins touch screens, proximity switches and some liquid-level sensors. Measurement methods include oscillator-based circuits, RC time constants or charge-displacement techniques, often with calibration to compensate for parasitic and environmental effects.

Common advantages include non-contact operation, robustness to dust and mechanical wear, and fast response. Limitations involve sensitivity to stray capacitances, humidity, temperature and the need for careful layout and calibration. Kapacitní approaches are widely used in consumer electronics, instrumentation and industrial sensing to provide user interfaces or non-contact sensing capabilities.