Patent ID: 7746670

Claim:
A two-transformer type of DC-to-DC converter comprising a first transformer having a first winding, a second winding and a third winding, and a second transformer having a fourth winding, a fifth winding and a sixth winding, with respective first ends of said first and fourth windings connected to form a first winding pair, respective first ends of said second and fifth windings connected to form a second winding pair, and respective second ends of said fourth and fifth windings connected together, a first DC terminal and second DC terminal for connecting said DC-to-DC converter to a first external circuit, and a third DC terminal and fourth DC terminal for connecting said DC-to-DC converter to a second external circuit, a first AC/DC conversion circuit connected between said first and second DC terminals and said first, second, fourth and fifth windings, for performing conversion between DC electrical power and AC electrical power, a second AC/DC conversion circuit connected between said third and fourth DC terminals and said second and third windings, for performing conversion between DC electrical power and AC electrical power, and a control circuit adapted to control said conversion operations of said first A/D converter and said second AC/DC conversion circuit; wherein said first AC/DC conversion circuit comprises: a first switching element controlled to periodically switch between closed and opened states for respectively connecting and disconnecting said first DC terminal to/from a junction of said second ends of the fourth and fifth windings, a second switching element controlled to periodically switch between said opened and closed states for respectively connecting and disconnecting said second DC terminal to/from said junction, a first capacitor connected between said first DC terminal and a second end of said second winding, and a second capacitor connected between said second DC terminal and a second end of said first winding.