Patent ID: 7078868

Claim:
A DC—DC converter of the voltage reduction-buck type comprising: a direct current source (Vin); an ON-OFF-controllable main switching device (Qx); a main coil (Lx) which is series connected to the main switching device (Qx); a fly-wheel diode (Dx) arranged such that the induction current of the main coil (Lx) flows when the main switching device (Qx) is shifted into the OFF state; a smoothing capacitor (Cx) for smoothing the output of the main coil (Lx); an auxiliary coil (Lw); a resonant capacitor (Cw); and an ON-OFF-controllable auxiliary switching device (Qw), wherein the auxiliary switching device (Qw) and the resonant capacitor (Cw) are series-connected to form a series connection, the series connection, the auxiliary coil (Lw) and the DC source (Vin) being connected in series to form a closed loop, wherein the series connection, the main switching device (Qx) and the fly-wheel diode (Dx) are series connected and form a closed loop, and wherein the main switching device (Qx) and the auxiliary switching device (Qw) are controlled such that they are alternatively shifted into the ON state and the main switching device (Qw) is shifted into the ON state within a given time after the auxiliary switching device (Qw) has been shifted into the OFF state.