A conventional E-t curve for a.c. cyclic oscillochronopotentiometry can be parameterized approximately by three groups of quantities reflecting the inflection potentials, the phase angles of the inflections and the steepness of the oscillogram. Expressions are given in terms of these three parameters for the amplitudes of all the Fourier components of an E-t curve. Verification of the theoretical prediction is carried out with reference to experimental results. Application of the harmonic potentials to practical analysis is explored.