# RLC CIRCUIT

Cuthbert Nyack
The RLC circuit is shown schematically above.

The differential equation shown above obtained from Kirchoff's eqns can be used to determine the output for any arbitrary input. The applet below shows the transient behaviour of the series RLC circuit for several different inputs. Changing the parameter Fn changes the input. The current i in the circuit is given by i = dq/dt

In the applet below Scrollbar 0 sets the parameter Fn which sets the function of the applet.

Fn = 0 shows the unit step response. Fn = 1,2 and 3 shows underdamped, critically damped and overdamped cases.

Fn = 4 shows the response to a sine. Fn = 5 and 6 shows resonant and off resonant cases for a sine input.

Fn = 7 shows the response to a steady state sinusoid. Fn = 8, 9 and 10 show low freq, res freq and high freq responses.

Fn = 11 shows the response to a swept frequency input. Fn = 12 and 13 are special cases.

Fn = 14 shows the response to a rectified sine. Fn = 15 and 16 show resonant and off resonant cases.

Fn = 17 shows the response to a square wave. Fn = 18, 19 and 20 show low freq, res freq and harmonic frequency response.

Fn = 21 shows the response to a triangle wave. Fn = 22, 23 and 24 show low freq, res freq and harmonic frequency response.

Fn = 25 shows the response to a ramp wave. Fn = 26 and 27 show low freq, and res frequency response.

Fn = 28 shows the response to a rectangular pulse sequence. Fn = 29 the low frequency response and Fn = 30 shows the circuit driven to resonance by a narrow rectangular pulse.

Fn = 31 shows the wave packet response. Fn = 32, 33 and 34 show special cases for different values of zeta.

Fn = 35 shows the response to an AM signal. Fn = 36, 37 and 38 show special cases for the AM response.

Fn = 39 shows the response to an FM signal. Fn = 40, 41, 42 and 43 show special cases for the FM response.