Apparatus for noise current reduction in power converters

A switching power converter with reduced common mode noise, the switching power converter comprising:

• a transformer with a primary winding and a secondary winding;
• at least one terminal on an input side;
• at least one terminal on an output side;
• and
• at least one counter-acting winding coupled to the primary winding and the secondary winding, the at least one counter-acting winding providing a counter-acting voltage to reduce a signal potential difference corresponding to the common mode noise.

A method for reduction of common mode noise comprising:

• providing a switching power converter having an input side terminal and an output side terminal;
• providing means for sensing a signal potential difference corresponding to a common mode noise;
• providing an amplifying device having at least one input connection that receives the signal potential difference, and at least one output connection that provides a counter-acting voltage in response to the signal potential difference;
• and
• providing means for coupling the at least one output connection of the amplifying device to a path connecting the input terminal to the output terminal whereby the counter-acting voltage produced by the amplifying device reduces the potential difference between the input side terminal and the output side terminal.