Just for quick reference, what would the effect be if a transformer's secondary and primary windings had the same number of turns? This might be ablittle vague, so let's say 12v AC supplying 12 Amps at 60Hz or 12v DC supplying 12 amps.
Generally it is converted to AC first, put thru a transformer, then converted back to DC at the other end..(normal with stepping up, not so common with stepping down).
If its just a small step down, then the DC can just be divided/series passed/shunt passed.