Värähtelypiirin

Värähtelypiiri, often translated as resonant circuit or oscillating circuit, is an electrical circuit that exhibits electrical resonance, a phenomenon where the circuit oscillates at a particular frequency. These circuits are fundamental components in a wide range of electronic devices. The most basic form of a värähtelypiiri consists of an inductor (L) and a capacitor (C). When these components are connected, they can store and release electrical energy cyclically, leading to oscillations.

The resonant frequency of an LC circuit is determined by the values of the inductor and capacitor according to the formula f = 1 / (2π√(LC)). At this frequency, the impedance of the inductor and capacitor are equal in magnitude but opposite in phase, resulting in a minimal overall impedance for a series circuit and a maximal impedance for a parallel circuit. This frequency selectivity is the key characteristic that makes värähtelypiiri useful.

Värähtelypiiri are extensively used in radio transmitters and receivers for tuning into specific frequencies, in signal generators to produce waveforms, and in filters to select or reject certain frequency bands. They are also crucial in switching power supplies and various other electronic applications where controlled oscillation or frequency selection is required. The presence of resistance in the circuit, though often minimized, can dampen the oscillations and affect the quality factor of the resonance.