[Amps] buck-boost (b-b)

[carl seyersdahl]

 In using an "external" transformer secondary (maybe 12vac) to raise or
lower the line voltage in subject manner, what is the current requirement of
the added winding?? will it be the same as the total current , as it seems ,
or just the additional current ( or power) needed to raise (or lower) the
line voltage.?? (power)
   I'm building a line voltage adjustment unit and altho my transformer can
easily handle 10 amps I'm still curious about this.!!
      (it's the little things that make me curious )
      carl / kz5ca