  We obtain the latitude-time distribution of the averaged tilt angle of solar
bipoles. For large bipoles, which are mainly bipolar sunspot groups, the
spatially averaged tilt angle is positive in the Northern solar hemisphere and
negative in the Southern, with modest variations during course of the solar
cycle. We consider the averaged tilt angle to be a tracer for a crucial element
of the solar dynamo, i.e. the regeneration rate of poloidal large-scale
magnetic field from toroidal. The value of the tilt obtained crudely
corresponds to a regeneration factor corresponding to about 10% of r.m.s.
velocity of solar convection. These results develop findings of Kosovichev and
Stenflo (2012) concerning Joy's law, and agree with the usual expectations of
solar dynamo theory. Quite surprisingly, we find a pronounced deviation from
these properties for smaller bipoles, which are mainly solar ephemeral regions.
They possess tilt angles of approximately the same absolute value, but of
opposite sign compared to that of the large bipoles. Of course, the tilt data
for small bipoles are less well determined than those for large bipoles;
however they remain robust under various modifications of the data processing.
