3.3.1 - I'' + RI'/L + I/LC = F/L cos wt

Electric circuit

Solutions to Second Order Differential Equations

Variation of parameters

Laplace Transform

Undetermined Coefficients

f(t) = exponential exp(st), y(t) = Y exp(st)

f(t) = Acos wt + Bsin wt, y(t) = MCos wt + NSin wt

f(t) = polynomial t, y(t) = polynomial t

yp(t) = c1(t) y1(t) + c2(t) y2(t)

Wronskian

Transform of f(t) = integral 0 to infinite of f(t) * exp(-st)

Damping

Overdamping

R > 2 sqrt(L/C)

2 Real Roots

Critical damping

R = 2 sqrt(L/C)

2 Equal Real Roots

Underdamping

R < 2 sqrt(L/C)

2 Complex Roots

No damping

R = 0

2 Real Roots

R = Resistor, C = Capacitor, L = Inductor

Series

Series RL Circuit

Series RC Circuit

Series RLC Circuit image

Series LC Circuit

Parallel

Parallel RL Circuit

Parallel RC Circuit

Parallel RLC Circuit

Parallel LC Circuit