Abstract: A current drive apparatus in a DC-converter including a pair of alternately conducting power transistors. The drive apparatus includes two drive transistors and a first and second drive transformer. The primary winding of the two transformers is connected via a drive transistor to one terminal of the DC-source and the secondary winding is connected to the control circuit of each power transistor. A further transformer, not being magnetically coupled to the two drive transformers, has two windings connected to the main current path of the power transistors and a further winding connected to one end of the primary windings of the drive transformer in order to couple a fraction of the current through a conducting power transistor to the control circuit of the same transistor. A capacitor is connected across each of said primary windings and each of said drive transistors to provide additional blocking voltage to the non-conducting power transistor.