RLC Impedance Calculator
Calculate complex impedance, phase angle, and AC circuit parameters for series and parallel RLC circuits
Calculate RLC Circuit Impedance
Resistance value in the RLC circuit
Inductance value of the inductor
Capacitance value of the capacitor
Operating frequency of the AC signal
RLC Impedance Analysis Results
Series RLC Circuit:
Impedance: Z = √(R² + (ωL - 1/ωC)²)
Phase angle: φ = arctan((ωL - 1/ωC)/R)
Angular frequency: ω = 0.00 rad/s
Impedance Characteristics
Example Calculation
Audio Crossover Network
Application: Audio speaker crossover at 1 kHz
Resistance (R): 8 Ω (speaker impedance)
Inductance (L): 2 mH (tweeter protection)
Capacitance (C): 10 μF (woofer coupling)
Frequency: 1 kHz (crossover frequency)
Circuit Type: Series RLC for frequency filtering
Calculation Results
ω = 2π × 1000 = 6283.18 rad/s
XL = ωL = 6283.18 × 0.002 = 12.57 Ω
XC = 1/(ωC) = 1/(6283.18 × 10×10⁻⁶) = 15.92 Ω
X = XL - XC = 12.57 - 15.92 = -3.35 Ω
Z = √(8² + (-3.35)²) = √(64 + 11.22) = 8.67 Ω
φ = arctan(-3.35/8) = -22.7° (capacitive)
Impedance Components
Resistance (R)
Real component that dissipates energy as heat. Independent of frequency.
Inductive Reactance (XL)
Reactive component from inductors. XL = ωL, increases with frequency.
Capacitive Reactance (XC)
Reactive component from capacitors. XC = 1/(ωC), decreases with frequency.
Phase Angle Guide
φ = 0°
Purely resistive - V and I in phase
φ > 0°
Inductive - voltage leads current
φ < 0°
Capacitive - voltage lags current
φ = ±90°
Purely reactive - no power dissipation
Quick Reference
Understanding RLC Circuit Impedance
What is Impedance?
Impedance is the total opposition to current flow in an AC circuit, combining both resistance (real part) and reactance (imaginary part). Unlike resistance, impedance varies with frequency and can be represented as a complex number with both magnitude and phase components.
Complex Impedance
- •Z = R + jX (rectangular form)
- •|Z| = √(R² + X²) (magnitude)
- •φ = arctan(X/R) (phase angle)
- •X = XL - XC (net reactance)
Frequency Response
Series RLC Circuit
- • Same current flows through all components
- • Voltages add: V = VR + VL + VC
- • Impedance: Z = R + j(XL - XC)
- • Minimum impedance at resonance
- • Used in bandpass filters and tuned circuits
Parallel RLC Circuit
- • Same voltage across all components
- • Currents add: I = IR + IL + IC
- • Admittance: Y = G + j(BC - BL)
- • Maximum impedance at resonance
- • Used in tank circuits and oscillators