Suppose D = 0; tuning the stiffnesses ratio B/A the corresponding eigenfrequencies of the system are varied; the maximum coupling
corresponds to B = A, where all the eigenvectors have equal electrical and mechanical contents.

Eigenfrequencies versus B/A.

When B = A, then there is a complete energy transformation from mechanical to electrical form.

Consider the system with purely mechanical initial conditions; the plot represents the time-evolutions of the four energies involved:
- blue scales: the elastic and   kinetic energies,
- yellow and green:     the capacitive and inductive energies