Patent ID: 7355373

Claim:
A DC-DC-converter comprising an inductive element, a unidirectional element coupled to the inductive element, a switching element coupled to the inductive element and the unidirectional element, control circuitry comprising an integrated circuit and coupled to a control electrode of the switching element for alternately rendering the switching element conductive and maintaining the switching element in a conductive state and rendering the switching element non-conductive and maintaining the switching element in a non-conductive state, characterized in that the control circuitry further comprises a secondary winding magnetically coupled to the inductive element and electrically coupled to a control electrode of the switching element, in that the secondary winding provides part of the energy for rendering the switching element conductive directly to the control electrode of the switching element, in that the switching element is rendered non-conductive by means of a signal generated by the integrated circuit and is maintained in the conductive and in the non-conductive state by a voltage across the secondary winding.