a) Time evolution of the volume averaged magnetic energy in the domain scaled with the equipartition energy for models with R_m = 2 × 10³ and κ₀ = 10^-5 (∗ ) as well as with R_m = 2 × 10⁵ and κ₀ = 10^-5 (solid line) for the interface dynamo model of Sect. 3.1 with dynamical α quenching. The saturation curve for zero fluxes for the model with R_m = 2 × 10⁵ has been shown by the dashed line; b) and c) show time-latitude diagrams for the toroidal field at the depths indicated for models with R_m = 2 × 10³ and κ₀ = 10^-5.