A circuit for use with a stator winding of a rotating or linear electrical machine, the stator winding having a number of coils linked by the same number of points of common coupling, includes an electronic commutator circuit having the same number of switching stages, each connected between a respective one of the points of common coupling and first and second main dc lines. Each switching stage includes first and second reverse blocking semiconductor power devices. A voltage clamping circuit includes the same number of clamping stages, each connected between a respective one of the points of common coupling and first and second auxiliary dc lines. Each clamping stage includes first and second diodes and first and second capacitors common to the various clamping stages. A dc to dc converter selectively discharges the first and second capacitors to the first and second main dc lines.