An electromagnetic interference suppression circuit, comprising: a sensing circuit with an input adapted to be connected on a power line and in series between a load and a shunt circuit connected across power lines between a power source and the load; an output operatively coupled with the input, and adapted to provide a signal (Vs) associated with an electromagnetic interference signal (Vn) generated by or at the load and arranged to be experienced by the shunt circuit for determining a suppression signal (Vn') for reducing, or substantially eliminating, the electromagnetic interference signal (Vn); a transformer with primary and secondary coils; and a capacitive circuit; a regulator circuit adapted to regulate the signal (V s) provided by the sensing circuit to provide a regulated signal; and a controlled signal source adapted to provide, based on the regulated signal, a suppression signal (V n') for reducing, or substantially eliminating, the electromagnetic interference signal (V n); characterized in that: the capacitive circuit is connected in parallel with the transformer; one of the transformer and the capacitive circuit provides the input and the other one of the transformer and the capacitive circuit provides the output; and the transformer and the capacitive circuit define a resonator circuit providing the input, the output, or both the input and the output. a sensing circuit with an input adapted to be connected on a power line and in series between a load and a shunt circuit connected across power lines between a power source and the load; an output operatively coupled with the input, and adapted to provide a signal (Vs) associated with an electromagnetic interference signal (Vn) generated by or at the load and arranged to be experienced by the shunt circuit for determining a suppression signal (Vn') for reducing, or substantially eliminating, the electromagnetic interference signal (Vn); a transformer with primary and secondary coils; and a capacitive circuit; an input adapted to be connected on a power line and in series between a load and a shunt circuit connected across power lines between a power source and the load; an output operatively coupled with the input, and adapted to provide a signal (Vs) associated with an electromagnetic interference signal (Vn) generated by or at the load and arranged to be experienced by the shunt circuit for determining a suppression signal (Vn') for reducing, or substantially eliminating, the electromagnetic interference signal (Vn); a transformer with primary and secondary coils; and a capacitive circuit; a regulator circuit adapted to regulate the signal (V s) provided by the sensing circuit to provide a regulated signal; and a controlled signal source adapted to provide, based on the regulated signal, a suppression signal (V n') for reducing, or substantially eliminating, the electromagnetic interference signal (V n); characterized in that: the capacitive circuit is connected in parallel with the transformer; one of the transformer and the capacitive circuit provides the input and the other one of the transformer and the capacitive circuit provides the output; and the transformer and the capacitive circuit define a resonator circuit providing the input, the output, or both the input and the output. the capacitive circuit is connected in parallel with the transformer; one of the transformer and the capacitive circuit provides the input and the other one of the transformer and the capacitive circuit provides the output; and the transformer and the capacitive circuit define a resonator circuit providing the input, the output, or both the input and the output.