The
auto-transformer is a particular type of transformer consisting of a single
winding equipped with intermediate sockets.
Compared to
the common transformer, having only one winding greatly simplifies
construction, greatly
reduces ohmic losses due to conductor resistance and eliminates insulation
problems between windings.
For these reasons, the autotransformer will be
cheaper, smaller and lighter than the standard transformer.
On the other hand,
unlike the normal transformer, it does not offer galvanic isolation between the
windings, an important feature in certain types of applications and work
contexts.