Patent ID: 7672147

Claim:
A power converter comprising: an output filter circuit including first and second inductive elements; a voltage source coupled to the output filter circuit, the voltage source for generating a voltage across the output filter circuit, the voltage including an alternating voltage component, the alternating voltage component causing the application of an alternating current to the first inductive element of the output filter circuit; and an attenuation filtering circuit comprising: a first magnetically coupled inductive arrangement for generating a first opposing alternating current in response to the alternating voltage applied to the first inductive element of the output filter circuit; a first combining element for combining the first opposing alternating current with the alternating current to partially cancel the alternating current, thereby producing an attenuated alternating current applied to the second inductive element of the output filter circuit, the first magnetically coupled inductive arrangement and the first combining element forming a first filter stage; a second magnetically coupled inductive arrangement for generating a second opposing alternating current in response to the attenuated alternating current applied to the second inductive element of the output filter circuit; a second combining element for combining the second opposing alternating current with the attenuated alternating current to substantially cancel the attenuated alternating current, the second magnetically coupled inductive arrangement and the second combining element forming a second filter stage; and an intermediate capacitor between the first and second filter stages.