Kapasitativt

Kapasitativt is an adjective used in electronics to describe phenomena related to capacitance, the property of a system to store electric charge in an electric field. In English, the corresponding terms are capacitive or capacitively. The concept applies to capacitors, capacitive sensing, and any circuit where reactive current is dominated by capacitance.

Capacitance C depends on geometry and material; for a parallel-plate capacitor, C = ε0 εr A/d. In AC circuits, a capacitor presents an impedance Zc = 1/(j ω C) and causes current to lead voltage by 90 degrees. At higher frequencies, capacitive reactance Xc = 1/(2π f C) decreases, altering impedance and current flow.

Capacitive behavior is exploited in many applications: energy storage, filtering, coupling between circuit stages, timing with RC networks, and capacitive sensing and touch detection. Capacitive sensors detect changes in capacitance caused by the presence of a finger, a dielectric material, or proximity. In power electronics, capacitive loads affect power factor and voltage regulation.

Design considerations include dielectric properties, temperature dependence, leakage currents, parasitic elements such as equivalent series resistance and inductance, and effects of parasitic capacitances at high frequency. Understanding capacitive behavior is essential for impedance matching, signal integrity, and sensor calibration.