  We assess the global-scale dynamo action achieved in a simulation of a
sun-like star rotating at three times the solar rate. The 3-D MHD Anelastic
Spherical Harmonic code, using slope-limited diffusion, is employed to capture
convection and dynamo processes in such a young sun. The simulation is carried
out in a spherical shell that encompasses 3.8 density scale heights of the
solar convection zone. We find that dynamo action with a high degree of time
variation occurs, with many periodic polarity reversals every 6.2 years. The
magnetic energy also rises and falls with a regular period, with two magnetic
energy cycles required to complete a polarity cycle. These magnetic energy
cycles arise from a Lorentz-force feedback on the differential rotation,
whereas the polarity reversals are present due to the spatial separation of the
equatorial and polar dynamos. Moreover, an equatorial migration of toroidal
field is found, which is linked to the changing differential rotation and to a
near-surface shear layer. This simulation also enters a grand minimum lasting
roughly 20 years, after which the dynamo recovers its regular polarity cycles.
