Stepping AC line voltage regulator

A stepping voltage regulator comprising a pair of input terminals connectable to a source of AC power, a pair of output terminals connectable to a load, a pair of lines connecting the two pair of terminals, a transformer having a secondary winding connected in series in one line and having at least four primary windings, a first primary winding being connected [through a first switch] in a first series circuit from one line through a first switch to the other line, a second primary winding being connected [through a second switch] in a second series circuit from said one line through a second switch to the other line, a third primary winding having one end connected through a third switch to the [end of] first series circuit between the first winding and the first switch, a fourth primary winding having one end connected through a fourth switch to the [end of] second series circuit between the second winding and the second switch , said one end of the third winding and said one end of the fourth [windings] winding having a common junction, a fifth switch connected between the other end of the third winding and the other line, a sixth switch connected between the other end of the fourth winding and the other line, [each of said windings having the same number of turns,] said first and third windings when energized inducing one direction of correcting voltage in the secondary winding and said second and fourth windings inducing the opposite direction of correcting voltage, switch control means for providing a selected conduction state [of only one of either] among plural conduction states of said switches including at least (a ) the first switch only , [or] ( b) only the third and fifth switches simultaneously, [or] ( c) only the fifth and sixth switches simultaneously, [or] ( d) only the fourth and sixth switches simultaneously [or] and (e) the second switch only, and detector means for sensing the value of the output voltage and providing a correcting signal to the switch control means to cause the switch control means to change to a different conduction state when the value of the output voltage exceeds a selected range of values.