RLC series circuit

Learning objectives

To study the harmonic response of a second order circuit.
To illustrate the influence of different parameters on the form of the response.

An RLC series circuit is powered by a sinusoidal voltage source of variable frequency v_E(t) = V_E.cos(2πft). The current i(t)is the same throughout the circuit. It is, like the entry voltage, sinusoidal but its amplitude and phase depend on the frequency: i(t) = I.cos(2πft + φ)

The voltage v_R(t) observed on the oscilloscope is a reflection of the current (v_R(t) = Ri(t)). The amplitude reaches a maximum for a certain frequency, called the resonance frequency f₀. It depends only on L and C.