US 6,982,621 B2
Method and apparatus for substantially reducing electrical displacement current flow between input and output windings of an energy transfer element
Chan Woong Park, San Jose, Calif. (US)
Assigned to Power Integrations, Inc., San Jose, Calif. (US)
Filed on Apr. 01, 2003, as Appl. No. 10/405,373.
Prior Publication US 2004/0196668 A1, Oct. 07, 2004
Int. Cl. H01F 27/02 (2006.01)
U.S. Cl. 336—84C 9 Claims
OG exemplary drawing
 
1. An energy transfer element, comprising:
an input winding to be coupled to an input circuit;
an output winding to be coupled to an output circuit;
an electrically conductive shield coupled to the input winding; and
a first cancellation winding to be coupled through a switch to the input winding only when the switch is closed, the first cancellation winding wound to substantially reduce a net capacitive displacement current between the input circuit and the output circuit.