U_0 = 5 (slider from -5 to 5, step 1)
φ = -1.1331853071795859 (slider from -6.283185307179586 to 6.28318531, step 0.05)
ω = 11.75 (slider from 0 to 50, step 0.05)
ψ: φ - atan(ω)
E_m = 3 (slider from -5 to 5, step 0.05)
U_m: E_m / sqrt(1 + ω)
A: U_0 - (U_m * cos(ψ))
e(t) = (E_m * cos((ω * t) + φ))
u_C(t) = If[t > 0, (A * ℯ^((-t))) + (U_m * cos((ω * t) + ψ)), U_0]