This document compares series and parallel resonance circuits. It shows that parallel resonance circuits have maximum impedance and minimum supply current, while series resonance circuits have minimum impedance and maximum supply current. Both have a phase angle of zero degrees for the supply current. The key difference is that parallel resonance can produce a voltage across the inductor and capacitor that exceeds the supply voltage, while series resonance produces a circulating current between the inductor and capacitor.

1. Comparing series and parallel circuits
Parallel resonance Series resonance
Impedance (Z) maximum minimum
Supply current (I) minimum maximum
Phase angle of I 0⁰ (zero) 0⁰ (zero)
voltage across L and C
circulating current
Effect can exceed the supply
between L and C
voltage

2. Comparing series and parallel circuits
Parallel resonance Series resonance
Impedance (Z) maximum minimum
Supply current (I) minimum maximum
Phase angle of I 0⁰ (zero) 0⁰ (zero)
voltage across L and C
circulating current
Effect can exceed the supply
between L and C
voltage

3. Comparing series and parallel circuits
Parallel resonance Series resonance
Impedance (Z) maximum minimum
Supply current (I) minimum maximum
Phase angle of I 0⁰ (zero) 0⁰ (zero)
voltage across L and C
circulating current
Effect can exceed the supply
between L and C
voltage

10. Refer to Electrical Trade
Principles p. 202-207 by
Hampson & Hanssen