AC2 Fundamentals Unit 2 – Series Resonance
Exercise 1 – Series Resonant Circuits
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to compute the resonant frequency,
total current, and impedance in a series RLC circuit by using standard formulas and procedures.
You will verify your results with an oscilloscope.
DISCUSSION
- This formula is used to calculate resonant frequency: fr = 1/[2π(sqrt(LC))]
- Capacitive reactance and inductive reactance are equal at the circuit resonant frequency.
- The total circuit impedance, at the resonant frequency, is equal to the circuit resistance.
- At resonance, total circuit current is calculated using Ohm’s law, total circuit resistance, and
applied voltage. - Individual voltage drops can be calculated using Ohm’s law when the component reactance
and total circuit current are known. - A circuit operating at resonance behaves as if it were a completely resistive circuit; therefore,
the applied voltage and circuit current are in phase. - The voltage drop across the reactive components is equal since this is a series circuit.