• $summary_{type}$: application
• $word_{count}$: 150

In parallel AC circuits, voltage is common and currents add as phasors. For parallel LCR: total current I = sqrt($I_R^2$ + ($I_L$ - $I_C$)^2), where $I_R$ = $\frac{V}{R}$, $I_L$ = $\frac{V}{X_L}$, $I_C$ = $\frac{V}{X_C}$. The admittance Y = 1/Z. At resonance in a parallel LC circuit (anti-resonance): $I_L$ = $I_C$, total current is minimum (ideally zero for pure L and C), and impedance is maximum. This is the opposite of series resonance (where Z is minimum). Resonant frequency: same formula $omega_0$ = 1/sqrt(LC). A parallel LC circuit at resonance acts as a band-stop filter (rejects the resonant frequency). In practice, the inductor has resistance r: at resonance, Z = $\frac{L}{Cr}$ (dynamic impedance), and the circuit draws a small current V*Cr/L. Parallel resonant circuits are used in oscillators and frequency-selective networks.