A high-voltage transformer (100, 600) comprising: a transformer core having a toroid shape; a primary winding comprising a conductive sheet that is wound at least partially around the transformer core; a secondary winding comprising a single conductor wound around the transformer core a plurality of times in two or more groupings of windings arranged around different sections of the transformer core such that each grouping of windings comprises a first winding having a first turn distance (a i, A i) along a circumference of the transformer core between adjacent turns of the first winding, and a first core to turn distance (r i, R i) along a radial direction between turns of the first winding and the transformer core; and a second winding having a second turn distance (a i, A i) along the circumference of the transformer core between adjacent turns of the second winding, and a second core to turn distance (r i, R i) along the radial direction turns of the second winding and the transformer core; wherein the second turn distance is greater than the first turn distance and the second core o turn distance is greater than the first core to turn distance; an input (V in) electrically coupled with the primary winding; and an output (V out) electrically coupled with the secondary winding that provides a voltage greater than 1200 volts. a transformer core having a toroid shape; a primary winding comprising a conductive sheet that is wound at least partially around the transformer core; a secondary winding comprising a single conductor wound around the transformer core a plurality of times in two or more groupings of windings arranged around different sections of the transformer core such that each grouping of windings comprises a first winding having a first turn distance (a i, A i) along a circumference of the transformer core between adjacent turns of the first winding, and a first core to turn distance (r i, R i) along a radial direction between turns of the first winding and the transformer core; and a second winding having a second turn distance (a i, A i) along the circumference of the transformer core between adjacent turns of the second winding, and a second core to turn distance (r i, R i) along the radial direction turns of the second winding and the transformer core; wherein the second turn distance is greater than the first turn distance and the second core o turn distance is greater than the first core to turn distance; an input (V in) electrically coupled with the primary winding; and an output (V out) electrically coupled with the secondary winding that provides a voltage greater than 1200 volts. a first winding having a first turn distance (a i, A i) along a circumference of the transformer core between adjacent turns of the first winding, and a first core to turn distance (r i, R i) along a radial direction between turns of the first winding and the transformer core; and a second winding having a second turn distance (a i, A i) along the circumference of the transformer core between adjacent turns of the second winding, and a second core to turn distance (r i, R i) along the radial direction turns of the second winding and the transformer core; wherein the second turn distance is greater than the first turn distance and the second core o turn distance is greater than the first core to turn distance; an input (V in) electrically coupled with the primary winding; and an output (V out) electrically coupled with the secondary winding that provides a voltage greater than 1200 volts.