A supercharger comprising a switched reluctance motor with a busbar assembly and a stator assembly, the stator assembly comprising a plurality of pairs of windings (203 A-C), each pair of windings comprising a first winding, for forming a first pole, connected in parallel with a second winding, for forming a second, diametrically opposite, pole, each winding having an input termination and an output termination, wherein the busbar assembly further comprises a plurality of pairs of busbars (209 A-C), each pair of busbars being substantially identical and being associated with a respective pair of windings, the plurality of pairs of busbars is rotationally symmetrical about a longitudinal axis of the stator assembly, and each pair of busbars (209 A-C)comprising: an input busbar connecting the input terminations of the first and second windings in the respective pair of windings (203 A-C), and an output busbar connecting the output terminations of the first and second windings in the respective pair of windings (203 A-C) and wherein the motor includes a control module for selectively energising each of the pairs of windings in the stator assembly, and wherein the input busbar of each pair of busbars being radially inside the input terminations of the first and second windings and the output busbar of each pair of busbars being radially inside the output terminations of the first and second windings, and wherein the busbars are arranged to radially overlap one after the other in a circle. each pair of windings comprising a first winding, for forming a first pole, connected in parallel with a second winding, for forming a second, diametrically opposite, pole, each winding having an input termination and an output termination, wherein the busbar assembly further comprises a plurality of pairs of busbars (209 A-C), each pair of busbars being substantially identical and being associated with a respective pair of windings, the plurality of pairs of busbars is rotationally symmetrical about a longitudinal axis of the stator assembly, and each pair of busbars (209 A-C)comprising: an input busbar connecting the input terminations of the first and second windings in the respective pair of windings (203 A-C), and an output busbar connecting the output terminations of the first and second windings in the respective pair of windings (203 A-C) and wherein the motor includes a control module for selectively energising each of the pairs of windings in the stator assembly, and wherein the input busbar of each pair of busbars being radially inside the input terminations of the first and second windings and the output busbar of each pair of busbars being radially inside the output terminations of the first and second windings, and wherein the busbars are arranged to radially overlap one after the other in a circle. an input busbar connecting the input terminations of the first and second windings in the respective pair of windings (203 A-C), and an output busbar connecting the output terminations of the first and second windings in the respective pair of windings (203 A-C) and wherein the motor includes a control module for selectively energising each of the pairs of windings in the stator assembly, and wherein the input busbar of each pair of busbars being radially inside the input terminations of the first and second windings and the output busbar of each pair of busbars being radially inside the output terminations of the first and second windings, and wherein the busbars are arranged to radially overlap one after the other in a circle.